WorldWideScience

Sample records for central amazon basin

  1. Impact of seasonal hydrological variation on the distributions of tetraether lipids along the Amazon River in the central Amazon basin: implications for the MBT/CBT paleothermometer and the BIT index

    NARCIS (Netherlands)

    Zell, C.; Kim, J.-H.; Abril, G.; Lima Sobrinho, R.; Dorhout, D.; Moreiro-Turcq, P.; Sinninghe Damsté, J.S.

    2013-01-01

    Suspended particulate matter (SPM) was collected along the Amazon River in the central Amazon basin and in three tributaries during the rising water (RW), high water (HW), falling water (FW) and low water (LW) season. Changes in the concentration and the distribution of branched glycerol dialkyl gly

  2. Aerosol emissions from forest and grassland burnings in the southern amazon basin and central Brazil

    Science.gov (United States)

    Leslie, Alistair C. D.

    1981-03-01

    hypothesized. A much more extensive field program for the summer of 1980 is planned to take place in the central Amazon basin using ground and airborne aerosol samplers, to capitalize on the work pioneered in this study.

  3. Spatial and seasonal contrasts of sedimentary organic matter in floodplain lakes of the central Amazon basin

    Science.gov (United States)

    Sobrinho, R. L.; Bernardes, M. C.; Abril, G.; Kim, J.-H.; Zell, C. I.; Mortillaro, J.-M.; Meziane, T.; Moreira-Turcq, P.; Sinninghe Damsté, J. S.

    2016-01-01

    In this study, we investigated the seasonal and spatial pattern of sedimentary organic matter (SOM) in five floodplain lakes of the central Amazon basin (Cabaliana, Janauaca, Canaçari, Mirituba and Curuai) which have different morphologies, hydrodynamics and vegetation coverages. Surface sediments were collected in four hydrological seasons: low water (LW), rising water (RW), high water (HW) and falling water (FW) in 2009 and 2010. We investigated commonly used bulk geochemical tracers such as the C : N ratio and the stable isotopic composition of organic carbon (δ13Corg). These results were compared with lignin phenol parameters as an indicator of vascular plant detritus and branched glycerol dialkyl glycerol tetraethers (brGDGTs) to trace the input of soil organic matter (OM) from land to the aquatic settings. We also applied the crenarchaeol as an indicator of aquatic (rivers and lakes) OM. Our data showed that during the RW and FW seasons, the surface sediments were enriched in lignin and brGDGTs in comparison to other seasons. Our study also indicated that floodplain lake sediments primarily consisted of allochthonous, C3 plant-derived OM. However, a downstream increase in C4 macrophyte-derived OM contribution was observed along the gradient of increasing open waters - i.e., from upstream to downstream. Accordingly, we attribute the temporal and spatial difference in SOM composition to the hydrological dynamics between the floodplain lakes and the surrounding flooded forests.

  4. Monoterpene Compositions of Three Forested Ecosystems in the Central Amazon Basin

    Science.gov (United States)

    Jardine, A.; Fuentes, J. D.; Manzi, A. O.; Higuchi, N.; Chambers, J. Q.; Jardine, K.

    2014-12-01

    Monoterpenes play fundamental roles as secondary metabolites in forested ecosystems and as gas and liquid phase secondary organic aerosol (SOA) precursors in their surrounding atmospheres. While the chemical pathways involved in ozonolysis driven SOA formation from individual monoterpene precursors is known, local and regional chemical transport models are still lacking observations of speciated monoterpenes from forested atmospheres. Here, we present high vertically resolved mixing ratio profiles of speciated monoterpenes from the ambient air of three neighboring forested ecosystems in the central Amazon Basin. Two well-drained plateau primary forests and one seasonally flooded valley forest were sampled during the afternoon hours (13:00 - 16:30) on walkup towers from the initiation of the 2013-14 wet season through the onset of the 2014 dry season (Nov 2013 - Jul 2014). Ambient mixing ratios in all three ecosystems were greatest in the upper canopy with secondary sources of some monoterpenes within the sub-canopies. Relative vertical compositions of monoterpenes did not change significantly throughout the seasons for either ecosystem type. Both ecosystem types were dominated by d-limonene (up to 1.6 ppb) with equally strong mixing ratios of alpha-pinene in the valley compared to the much weaker a-pinene mixing ratios on the plateaus (up to 200 ppt). The highly reactive cis- and trans-beta-ocimene were consistently present in both ecosystems (up to 250 ppt) with the addition of equally high camphene mixing ratios in the valley forest (up to 200 ppt) which is present in the plateau ecosystems in low quantities (50 ppt). With respect to clean atmosphere mixing ratios of 10 ppb ozone, lifetimes are below 2 hours for camphene and below 30 minutes for ocimene, suggesting a potentially large impact on local and possibly regional ozonolysis and subsequent SOA composition.

  5. Spatial variability of soil carbon stock in the Urucu river basin, Central Amazon-Brazil.

    Science.gov (United States)

    Ceddia, Marcos Bacis; Villela, André Luis Oliveira; Pinheiro, Érika Flávia Machado; Wendroth, Ole

    2015-09-01

    The Amazon Forest plays a major role in C sequestration and release. However, few regional estimates of soil organic carbon (SOC) stock in this ecoregion exist. One of the barriers to improve SOC estimates is the lack of recent soil data at high spatial resolution, which hampers the application of new methods for mapping SOC stock. The aims of this work were: (i) to quantify SOC stock under undisturbed vegetation for the 0-30 and the 0-100 cm under Amazon Forest; (ii) to correlate the SOC stock with soil mapping units and relief attributes and (iii) to evaluate three geostatistical techniques to generate maps of SOC stock (ordinary, isotopic and heterotopic cokriging). The study site is located in the Central region of Amazon State, Brazil. The soil survey covered the study site that has an area of 80 km(2) and resulted in a 1:10,000 soil map. It consisted of 315 field observations (96 complete soil profiles and 219 boreholes). SOC stock was calculated by summing C stocks by horizon, determined as a product of BD, SOC and the horizon thickness. For each one of the 315 soil observations, relief attributes were derived from a topographic map to understand SOC dynamics. The SOC stocks across 30 and 100 cm soil depth were 3.28 and 7.32 kg C m(-2), respectively, which is, 34 and 16%, lower than other studies. The SOC stock is higher in soils developed in relief forms exhibiting well-drained soils, which are covered by Upland Dense Tropical Rainforest. Only SOC stock in the upper 100 cm exhibited spatial dependence allowing the generation of spatial variability maps based on spatial (co)-regionalization. The CTI was inversely correlated with SOC stock and was the only auxiliary variable feasible to be used in cokriging interpolation. The heterotopic cokriging presented the best performance for mapping SOC stock.

  6. Spatial variability of soil carbon stock in the Urucu river basin, Central Amazon-Brazil

    International Nuclear Information System (INIS)

    The Amazon Forest plays a major role in C sequestration and release. However, few regional estimates of soil organic carbon (SOC) stock in this ecoregion exist. One of the barriers to improve SOC estimates is the lack of recent soil data at high spatial resolution, which hampers the application of new methods for mapping SOC stock. The aims of this work were: (i) to quantify SOC stock under undisturbed vegetation for the 0–30 and the 0–100 cm under Amazon Forest; (ii) to correlate the SOC stock with soil mapping units and relief attributes and (iii) to evaluate three geostatistical techniques to generate maps of SOC stock (ordinary, isotopic and heterotopic cokriging). The study site is located in the Central region of Amazon State, Brazil. The soil survey covered the study site that has an area of 80 km2 and resulted in a 1:10,000 soil map. It consisted of 315 field observations (96 complete soil profiles and 219 boreholes). SOC stock was calculated by summing C stocks by horizon, determined as a product of BD, SOC and the horizon thickness. For each one of the 315 soil observations, relief attributes were derived from a topographic map to understand SOC dynamics. The SOC stocks across 30 and 100 cm soil depth were 3.28 and 7.32 kg C m−2, respectively, which is, 34 and 16%, lower than other studies. The SOC stock is higher in soils developed in relief forms exhibiting well-drained soils, which are covered by Upland Dense Tropical Rainforest. Only SOC stock in the upper 100 cm exhibited spatial dependence allowing the generation of spatial variability maps based on spatial (co)-regionalization. The CTI was inversely correlated with SOC stock and was the only auxiliary variable feasible to be used in cokriging interpolation. The heterotopic cokriging presented the best performance for mapping SOC stock. - Highlights: • The SOC stocks across 30 and 100 cm depth were 3.28 and 7.32 kg C m−2, respectively. • SOC stocks were 34 and 16%, respectively, lower

  7. Spatial variability of soil carbon stock in the Urucu river basin, Central Amazon-Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Ceddia, Marcos Bacis, E-mail: marcosceddia@gmail.com [Department of Soil, Institute of Agronomy, Universidade Federal Rural do Rio de Janeiro (UFRRJ), Seropédica, RJ 23890-000 (Brazil); Villela, André Luis Oliveira [Colégio Técnico da UFRRJ, RJ, Seropédica 23890-000 (Brazil); Pinheiro, Érika Flávia Machado [Department of Soil, Institute of Agronomy, Universidade Federal Rural do Rio de Janeiro (UFRRJ), Seropédica, RJ 23890-000 (Brazil); Wendroth, Ole [Department of Plant & Soil Sciences, University of Kentucky, College of Agriculture, Lexington, KY (United States)

    2015-09-01

    The Amazon Forest plays a major role in C sequestration and release. However, few regional estimates of soil organic carbon (SOC) stock in this ecoregion exist. One of the barriers to improve SOC estimates is the lack of recent soil data at high spatial resolution, which hampers the application of new methods for mapping SOC stock. The aims of this work were: (i) to quantify SOC stock under undisturbed vegetation for the 0–30 and the 0–100 cm under Amazon Forest; (ii) to correlate the SOC stock with soil mapping units and relief attributes and (iii) to evaluate three geostatistical techniques to generate maps of SOC stock (ordinary, isotopic and heterotopic cokriging). The study site is located in the Central region of Amazon State, Brazil. The soil survey covered the study site that has an area of 80 km{sup 2} and resulted in a 1:10,000 soil map. It consisted of 315 field observations (96 complete soil profiles and 219 boreholes). SOC stock was calculated by summing C stocks by horizon, determined as a product of BD, SOC and the horizon thickness. For each one of the 315 soil observations, relief attributes were derived from a topographic map to understand SOC dynamics. The SOC stocks across 30 and 100 cm soil depth were 3.28 and 7.32 kg C m{sup −2}, respectively, which is, 34 and 16%, lower than other studies. The SOC stock is higher in soils developed in relief forms exhibiting well-drained soils, which are covered by Upland Dense Tropical Rainforest. Only SOC stock in the upper 100 cm exhibited spatial dependence allowing the generation of spatial variability maps based on spatial (co)-regionalization. The CTI was inversely correlated with SOC stock and was the only auxiliary variable feasible to be used in cokriging interpolation. The heterotopic cokriging presented the best performance for mapping SOC stock. - Highlights: • The SOC stocks across 30 and 100 cm depth were 3.28 and 7.32 kg C m{sup −2}, respectively. • SOC stocks were 34 and 16

  8. Modelling conservation in the Amazon basin

    Science.gov (United States)

    Soares-Filho, Britaldo Silveira; Nepstad, Daniel Curtis; Curran, Lisa M.; Cerqueira, Gustavo Coutinho; Garcia, Ricardo Alexandrino; Ramos, Claudia Azevedo; Voll, Eliane; McDonald, Alice; Lefebvre, Paul; Schlesinger, Peter

    2006-03-01

    Expansion of the cattle and soy industries in the Amazon basin has increased deforestation rates and will soon push all-weather highways into the region's core. In the face of this growing pressure, a comprehensive conservation strategy for the Amazon basin should protect its watersheds, the full range of species and ecosystem diversity, and the stability of regional climates. Here we report that protected areas in the Amazon basin-the central feature of prevailing conservation approaches-are an important but insufficient component of this strategy, based on policy-sensitive simulations of future deforestation. By 2050, current trends in agricultural expansion will eliminate a total of 40% of Amazon forests, including at least two-thirds of the forest cover of six major watersheds and 12 ecoregions, releasing 32 +/- 8Pg of carbon to the atmosphere. One-quarter of the 382 mammalian species examined will lose more than 40% of the forest within their Amazon ranges. Although an expanded and enforced network of protected areas could avoid as much as one-third of this projected forest loss, conservation on private lands is also essential. Expanding market pressures for sound land management and prevention of forest clearing on lands unsuitable for agriculture are critical ingredients of a strategy for comprehensive conservation.

  9. Impact of seasonal hydrological variation on the distributions of tetraether lipids along the Amazon River in the central Amazon basin: implications for the MBT/CBT paleothermometer and the BIT index.

    Science.gov (United States)

    Zell, Claudia; Kim, Jung-Hyun; Abril, Gwenaël; Sobrinho, Rodrigo Lima; Dorhout, Denise; Moreira-Turcq, Patricia; Sinninghe Damsté, Jaap S

    2013-01-01

    Suspended particulate matter (SPM) was collected along the Amazon River in the central Amazon basin and in three tributaries during the rising water (RW), high water (HW), falling water (FW) and low water (LW) season. Changes in the concentration and the distribution of branched glycerol dialkyl glycerol tetraethers (brGDGTs), i.e., the methylation index of branched tetraethers (MBT) and the cyclization of brGDGTs (CBT), were seen in the Amazon main stem. The highest concentration of core lipid (CL) brGDGTs normalized to particulate organic carbon (POC) was found during the HW season. During the HW season the MBT and CBT in the Amazon main stem was also most similar to that of lowland Amazon (terra firme) soils, indicating that the highest input of soil-derived brGDGTs occurred due to increased water runoff. During the other seasons the MBT and CBT indicated an increased influence of in situ production of brGDGTs even though soils remained the main source of brGDGTs. Our results reveal that the influence of seasonal variation is relatively small, but can be clearly detected. Crenarchaeol was mostly produced in the river. Its concentration was lower during the HW season compared to that of the other seasons. Hence, our study shows the complexity of processes that influence the GDGT distribution during the transport from land to ocean. It emphasizes the importance of a detailed study of a river basin to interpret the MBT/CBT and BIT records for paleo reconstructions in adjacent marine setting.

  10. Bold enterprise in Amazon basin

    Energy Technology Data Exchange (ETDEWEB)

    Johnston, D.

    1980-08-30

    The aim of the Jari project in Brazil is to produce food and forest products for world markets by developing a 15,000 square km tract in the Amazon basin. A pumpmill and power plant came on stream in 1979 and since then have been meeting production targets of high quality bleached pulp. The key to the success of the project has been the introduction of a fast-growing hardwood native to S.E. Asia- Gmelina arborea which reaches a height of 30 m after 10 years, and is suitable for most wood products: pulp, sawn timber, veneer, plywood and particleboard. It is stated that preparations are under-way to introduce Jari hardwood to European markets.

  11. Impact of seasonal hydrological variation on the distributions of branched and isoprenoid tetraether lipids along the Amazon River in the central Amazon basin: Implications for the MBT/CBT paleothermometer and the BIT index

    Science.gov (United States)

    Zell, Claudia; Kim, Jung-Hyun; Lima Sobrinho, Rodrigo; Moreira-Turcq, Patricia; Abril Abril, Gwenaël; Sinninghe Damsté, Jaap S.

    2013-04-01

    We assessed the effects of hydrodynamical variations on the distributions and sources of branched and isoprenoid glycerol dialkyl glycerol tetraethers (brGDGTs and isoGDGTs, respectively) transported by the Amazon River in the central Amazon basin. Particulate suspended matter was collected in the Amazonian rivers and floodplain lakes at four different seasons (rising water, high water, falling water, and low water) at 6 stations along the main stem of the Amazon River, 3 tributaries (Negro, Madeira, and Tapajós) and 5 floodplain lakes (Manacapuru, Janauacá, Mirituba, Canaçari and Curuai). The concentration and distribution of brGDGTs of both core lipid (CL) and intact polar lipid (IPL)-derived fractions were investigated applying IPL-derived brGDGTs as an indicator of brGDGTs derived from recently-living cells. The organic carbon (OC)-normalized concentrations of CL brGDGTs mimicked the trend of the hydrological variation with highest concentrations during the high water season. The CL brGDGT distributions were most alike those of lowland Amazon (terra firme) soils during the high water season, indicating that input of soil-derived, allochthonous brGDGTs to the Amazon River was highest at that period. Accordingly, the methylation index of branched tetraethers (MBT) and the cyclization ratio of branched tetraethers (CBT) varied corresponding to the hydrological changes, with the increasing influence of in situ produced brGDGTs in rivers and floodplain lakes during the low water season. The concentrations of CL crenarchaeol were highest during the low water season, due to increased autochthonous production. The concentration changes of both brGDGTs and crenarchaeol lead to a variation of the branched and isoprenoid tetraether (BIT) index between 0.4 (low water) and 0.9 (high water). Hence, our study hints at the effect of hydrodynamical variations on the source of brGDGTs and isoGDGTs transported by rivers to the ocean and emphasized the importance of a detailed

  12. Methane emissions from floodplain trees of the Amazon basin

    Science.gov (United States)

    Pangala, Sunitha; Bastviken, David; Enrich-Prast, Alex; Gauci, Vincent

    2016-04-01

    Wetlands are the largest source of methane to the atmosphere, but emission estimates are highly uncertain leading to large discrepancies between emission inventories and much larger estimates of the Amazon methane source derived at larger scales. We examined methane emissions from all emission pathways including aquatic surfaces, emergent soils and herbaceous vegetation and more than 2000 trees from 13 locations across the central Amazon floodplain in 2014. Our data are the first measurements of stem emission from emergent portions of inundated trees in the Amazon and they demonstrate that regionally, tree stems are the dominant means of emissions for soil produced methane to the atmosphere. Emissions via the range of egress pathways varied substantially between sample locations and water-table exerted some control over emissions from ~2m below the soil surface upto 0.5-1m of inundation. Higher water (upto ~10m of inundation) exerted no further control over emissions. Applying our measurements to models of whole tree emission and scaling to the entire Amazon lowland basin demonstrates the significant contribution of trees to regional emissions that can close the Amazon basin methane budget.

  13. Distribution of Aboveground Live Biomass in the Amazon Basin

    Science.gov (United States)

    Saatchi, S. S.; Houghton, R. A.; DosSantos Alvala, R. C.; Soares, J. V.; Yu, Y.

    2007-01-01

    The amount and spatial distribution of forest biomass in the Amazon basin is a major source of uncertainty in estimating the flux of carbon released from land-cover and land-use change. Direct measurements of aboveground live biomass (AGLB) are limited to small areas of forest inventory plots and site-specific allometric equations that cannot be readily generalized for the entire basin. Furthermore, there is no spaceborne remote sensing instrument that can measure tropical forest biomass directly. To determine the spatial distribution of forest biomass of the Amazon basin, we report a method based on remote sensing metrics representing various forest structural parameters and environmental variables, and more than 500 plot measurements of forest biomass distributed over the basin. A decision tree approach was used to develop the spatial distribution of AGLB for seven distinct biomass classes of lowland old-growth forests with more than 80% accuracy. AGLB for other vegetation types, such as the woody and herbaceous savanna and secondary forests, was directly estimated with a regression based on satellite data. Results show that AGLB is highest in Central Amazonia and in regions to the east and north, including the Guyanas. Biomass is generally above 300Mgha(sup 1) here except in areas of intense logging or open floodplains. In Western Amazonia, from the lowlands of Peru, Ecuador, and Colombia to the Andean mountains, biomass ranges from 150 to 300Mgha(sup 1). Most transitional and seasonal forests at the southern and northwestern edges of the basin have biomass ranging from 100 to 200Mgha(sup 1). The AGLB distribution has a significant correlation with the length of the dry season. We estimate that the total carbon in forest biomass of the Amazon basin, including the dead and below ground biomass, is 86 PgC with +/- 20% uncertainty.

  14. Bold enterprise in Amazon basin. [Gmelina arborea

    Energy Technology Data Exchange (ETDEWEB)

    Johnston, D.

    1980-08-30

    The aim of the Jari project in Brazil is to produce food and forest products for world markets by developing a 15,000 square km tract in the Amazon basin. A pulpmill and power plant came on stream in 1979 and since then have been meeting production targets of high quality bleached pulp. The key to the success of the project has been the introduction of a fast-growing hardwood native to S.E. Asia, Gmelina arborea, which reaches a height of 30 m after 10 years, and is suitable for most wood products, pulp, sawn timber, veneer, plywood, and particleboard. It is stated that preparations are under-way to introduce Jari hardwood to European markets.

  15. The impact of Amazonian deforestation on Amazon basin rainfall

    OpenAIRE

    Spracklen, DV; Garcia-Carreras, L.

    2015-01-01

    We completed a meta-analysis of regional and global climate model simulations (n=96) of the impact of Amazonian deforestation on Amazon basin rainfall. Across all simulations, mean (±1σ) change in annual mean Amazon basin rainfall was -12±11%. Variability in simulated rainfall was not explained by differences in model resolution or surface parameters. Across all simulations we find a negative linear relationship between rainfall and deforestation extent, although individual studies often simu...

  16. Forecasting terrestrial water storage changes in the Amazon Basin using Atlantic and Pacific sea surface temperatures

    Directory of Open Access Journals (Sweden)

    C. de Linage

    2013-10-01

    Full Text Available Floods and droughts frequently affect the Amazon River basin, impacting transportation, river navigation, agriculture, and ecosystem processes within several South American countries. Here we examined how sea surface temperatures (SSTs influence interannual variability of terrestrial water storage anomalies (TWSAs in different regions within the Amazon basin and propose a modeling framework for inter-seasonal flood and drought forecasting. Three simple statistical models forced by a linear combination of lagged spatial averages of central Pacific (Niño 4 index and tropical North Atlantic (TNAI index SSTs were calibrated against a decade-long record of 3°, monthly TWSAs observed by the Gravity Recovery And Climate Experiment (GRACE satellite mission. Niño 4 was the primary external forcing in the northeastern region of the Amazon basin whereas TNAI was dominant in central and western regions. A combined model using the two indices improved the fit significantly (p < 0.05 for at least 64% of the grid cells within the basin, compared to models forced solely with Niño 4 or TNAI. The combined model explained 66% of the observed variance in the northeastern region, 39% in the central and western regions, and 43% for the Amazon basin as a whole with a 3 month lead time between the SST indices and TWSAs. Model performance varied seasonally: it was higher than average during the rainfall wet season in the northeastern Amazon and during the dry season in the central and western regions. The predictive capability of the combined model was degraded with increasing lead times. Degradation was smaller in the northeastern Amazon (where 49% of the variance was explained using an 8 month lead time vs. 69% for a 1 month lead time compared to the central and western Amazon (where 22% of the variance was explained at 8 months vs. 43% at 1 month. These relationships may enable the development of an early warning system for flood and drought risk. This work also

  17. The Late Miocene paleogeography of the Amazon Basin and the evolution of the Amazon River system

    Science.gov (United States)

    Latrubesse, Edgardo M.; Cozzuol, Mario; da Silva-Caminha, Silane A. F.; Rigsby, Catherine A.; Absy, Maria Lucia; Jaramillo, Carlos

    2010-05-01

    On the basis of paleontological content (vertebrates and palynology) and facies analysis from river banks, road cuts, and three wells, we have assigned the uppermost levels of the Solimões Formation in western Amazonia, Brazil, to the Late Miocene. The vertebrate fossil record from outcropping sediments is assigned to the Huayquerian-Mesopotamian mammalian biozones, spanning 9-6.5 Ma. Additionally, we present results that demonstrate that deposits in Peruvian Amazonia attributed to Miocene tidal environments are actually fluvial sediments that have been misinterpreted (both environmentally and chronologically) by several authors. The entire Late Miocene sequence was deposited in a continental environment within a subsiding basin. The facies analysis, fossil fauna content, and palynological record indicate that the environment of deposition was dominated by avulsive rivers associated with megafan systems, and avulsive rivers in flood basins (swamps, lakes, internal deltas, and splays). Soils developed on the flatter, drier areas, which were dominated by grasslands and gallery forest in a tropical to subtropical climate. These Late Miocene sediments were deposited from westward of the Purus arch up to the border of Brazil with Peru (Divisor Ranges) and Bolivia (Pando block). Eastward of the Iquitos structural high, however, more detailed studies, including vertebrate paleontology, need to be performed to calibrate with more precision the ages of the uppermost levels of the Solimões Formation. The evolution of the basin during the late Miocene is mainly related to the tectonic behavior of the Central Andes (˜ 3°-15°S). At approximately 5 Ma, a segment of low angle of subduction was well developed in the Nazca Plate, and the deformation in the Subandean foreland produced the inland reactivation of the Divisor/Contamana Ranges and tectonic arrangements in the Eastern Andes. During the Pliocene southwestern Brazilian Amazonia ceased to be an effective sedimentary

  18. The impact of Amazonian deforestation on Amazon basin rainfall

    Science.gov (United States)

    Spracklen, D. V.; Garcia-Carreras, L.

    2015-11-01

    We completed a meta-analysis of regional and global climate model simulations (n = 96) of the impact of Amazonian deforestation on Amazon basin rainfall. Across all simulations, mean (±1σ) change in annual mean Amazon basin rainfall was -12 ± 11%. Variability in simulated rainfall was not explained by differences in model resolution or surface parameters. Across all simulations we find a negative linear relationship between rainfall and deforestation extent, although individual studies often simulate a nonlinear response. Using the linear relationship, we estimate that deforestation in 2010 has reduced annual mean rainfall across the Amazon basin by 1.8 ± 0.3%, less than the interannual variability in observed rainfall. This may explain why a reduction in Amazon rainfall has not consistently been observed. We estimate that business-as-usual deforestation (based on deforestation rates prior to 2004) would lead to an 8.1 ± 1.4% reduction in annual mean Amazon basin rainfall by 2050, greater than natural variability.

  19. Regional nitrous oxide flux in Amazon basin

    International Nuclear Information System (INIS)

    Nitrous oxide (N2O) is the third most important anthropogenic greenhouse gas. Globally, the main sources of N2O are nitrification and denitrification in soils. About two thirds of the soil emissions occur in the tropics and approximately 20% originate in wet rain forest ecosystems, like the Amazon forest. The work presented here involves aircraft vertical profiles of N2O from the surface to 4 km over two sites in the Eastern and Central Amazon: Tapajos National Forest (2000-2009) and Cuieiras Biologic Reserve (2004-2007), and the estimation of N2O fluxes for regions upwind of these sites using two methods: Column Integration Technique and Inversion Model - FLEXPART. To our knowledge, these regional scale N2O measurements in Amazonia are unique and represent a new approach to looking regional scale emissions. For the both methods, the fluxes upwind of Cuieiras Biologic Reserve exhibited little seasonality, and the annual mean was 1.9 ±1.6 mgN2Om-2day-1 for the Column Integration Technique and 2.3±0.9 mgN2Om-2day-1 for Inversion Model - FLEXPART. For fluxes upwind of Tapajos Nacional Forest, the Inversion Model - FLEXPART presented about half (0.9±1.7 mgN2Om-2day-1) of the Column Integration Technique (2.0±1.1 mgN2Om-2day-1) for the same period (2004-2008). One reason could be because the inversion model does not consider anthropic activities, once it had a good representation for less impacted area. Both regions presented similar emission during wet season. By Column Integration Technique, fluxes upwind Tapajos Nacional Forest were similar for dry and wet seasons. The dry season N2O fluxes exhibit significant correlations with CO fluxes, indicating a larger than expected source of N2O from biomass burning. The average CO:N2O ratio for all 38 profiles sampled during the dry season was 82±69 mol CO:molN2O and suggests a larger biomass burning contribution to the global N2O budget than previously reported. (author)

  20. Modelling basin-wide variations in Amazon forest photosynthesis

    Science.gov (United States)

    Mercado, Lina; Lloyd, Jon; Domingues, Tomas; Fyllas, Nikolaos; Patino, Sandra; Dolman, Han; Sitch, Stephen

    2010-05-01

    Given the importance of Amazon rainforest in the global carbon and hydrological cycles, there is a need to use parameterized and validated ecosystem gas exchange and vegetation models for this region in order to adequately simulate present and future carbon and water balances. Recent research has found major differences in above-ground net primary productivity (ANPP), above ground biomass and tree dynamics across Amazonia. West Amazonia is more dynamic, with younger trees, higher stem growth rates and lower biomass than central and eastern Amazon (Baker et al. 2004; Malhi et al. 2004; Phillips et al. 2004). A factor of three variation in above-ground net primary productivity has been estimated across Amazonia by Malhi et al. (2004). Different hypotheses have been proposed to explain the observed spatial variability in ANPP (Malhi et al. 2004). First, due to the proximity to the Andes, sites from western Amazonia tend to have richer soils than central and eastern Amazon and therefore soil fertility could possibly be highly related to the high wood productivity found in western sites. Second, if GPP does not vary across the Amazon basin then different patterns of carbon allocation to respiration could also explain the observed ANPP gradient. However since plant growth depends on the interaction between photosynthesis, transport of assimilates, plant respiration, water relations and mineral nutrition, variations in plant gross photosynthesis (GPP) could also explain the observed variations in ANPP. In this study we investigate whether Amazon GPP can explain variations of observed ANPP. We use a sun and shade canopy gas exchange model that has been calibrated and evaluated at five rainforest sites (Mercado et al. 2009) to simulate gross primary productivity of 50 sites across the Amazon basin during the period 1980-2001. Such simulation differs from the ones performed with global vegetation models (Cox et al. 1998; Sitch et al. 2003) where i) single plant functional

  1. Spectrometry of pasture condition and biogeochemistry in the central Amazon

    Science.gov (United States)

    Asner, Gregory P.; Townsend, Alan R.; Bustamante, Mercedes M. C.

    Regional analyses of Amazon cattle pasture biogeochemistry are difficult due to the complexity of human, edaphic, biotic and climatic factors and persistent cloud cover in satellite observations. We developed a method to estimate key biophysical properties of Amazon pastures using hyperspectral reflectance data and photon transport inverse modeling. Remote estimates of live and senescent biomass were strongly correlated with plant-available forms of soil phosphorus and calcium. These results provide a basis for monitoring pasture condition and biogeochemistry in the Amazon Basin using spaceborne hyperspectral sensors.

  2. Staphylococcus aureus causing tropical pyomyositis, Amazon Basin, Peru.

    NARCIS (Netherlands)

    Garcia, C.; Hallin, M.; Deplano, A.; Denis, O.; Sihuincha, M.; Groot, R. de; Gotuzzo, E.; Jacobs, J.

    2013-01-01

    We studied 12 Staphylococcus aureus isolates causing tropical pyomyositis in the Amazon Basin of Peru. All isolates were methicillin-susceptible; 11 carried Panton-Valentine leukocidin-encoding genes, and 5 belonged to multilocus sequence type 25 and possessed an extensive set of enterotoxins. Our f

  3. Andes hantavirus variant in rodents, southern Amazon Basin, Peru.

    Science.gov (United States)

    Razuri, Hugo; Tokarz, Rafal; Ghersi, Bruno M; Salmon-Mulanovich, Gabriela; Guezala, M Claudia; Albujar, Christian; Mendoza, A Patricia; Tinoco, Yeny O; Cruz, Christopher; Silva, Maria; Vasquez, Alicia; Pacheco, Víctor; Ströher, Ute; Guerrero, Lisa Wiggleton; Cannon, Deborah; Nichol, Stuart T; Hirschberg, David L; Lipkin, W Ian; Bausch, Daniel G; Montgomery, Joel M

    2014-02-01

    We investigated hantaviruses in rodents in the southern Amazon Basin of Peru and identified an Andes virus variant from Neacomys spinosus mice. This finding extends the known range of this virus in South America and the range of recognized hantaviruses in Peru. Further studies of the epizoology of hantaviruses in this region are warranted.

  4. Placentation in dolphins from the Amazon River Basin

    DEFF Research Database (Denmark)

    da Silva, Vera M F; Carter, Anthony M; Ambrosio, Carlos E;

    2007-01-01

    A recent reassessment of the phylogenetic affinities of cetaceans makes it timely to compare their placentation with that of the artiodactyls. We studied the placentae of two sympatric species of dolphin from the Amazon River Basin, representing two distinct families. The umbilical cord branched...

  5. Large-scale Modeling of Inundation in the Amazon Basin

    Science.gov (United States)

    Luo, X.; Li, H. Y.; Getirana, A.; Leung, L. R.; Tesfa, T. K.

    2015-12-01

    Flood events have impacts on the exchange of energy, water and trace gases between land and atmosphere, hence potentially affecting the climate. The Amazon River basin is the world's largest river basin. Seasonal floods occur in the Amazon Basin each year. The basin being characterized by flat gradients, backwater effects are evident in the river dynamics. This factor, together with large uncertainties in river hydraulic geometry, surface topography and other datasets, contribute to difficulties in simulating flooding processes over this basin. We have developed a large-scale inundation scheme in the framework of the Model for Scale Adaptive River Transport (MOSART) river routing model. Both the kinematic wave and the diffusion wave routing methods are implemented in the model. A new process-based algorithm is designed to represent river channel - floodplain interactions. Uncertainties in the input datasets are partly addressed through model calibration. We will present the comparison of simulated results against satellite and in situ observations and analysis to understand factors that influence inundation processes in the Amazon Basin.

  6. Basin-Wide Amazon Forest Tree Mortality From a Large 2005 Storm

    Science.gov (United States)

    Negron Juarez, R. I.; Chambers, J. Q.; Guimaraes, G.; Zeng, H.; Raupp, C.; Marra, D. M.; Ribeiro, G.; Saatchi, S. S.; Higuchi, N.

    2010-12-01

    Blowdowns are a recurrent characteristic of Amazon forests and are produced, among others, by squall lines. Squall lines are aligned clusters (typical length of 1000 km, width of 200 km) of deep convective cells that produce heavy rainfall during the dry season and significant rainfall during the wet season. These squall lines (accompanied by intense downbursts from convective cells) have been associated with large blowdowns characterized by uprooted, snapped trees, and trees being dragged down by other falling trees. Most squall lines in Amazonia form along the northeastern coast of South America as sea breeze-induced instability lines and propagate inside the continent. They occur frequently (~4 times per month), and can reach the central and even extreme western parts of Amazonia. Squall lines can also be generated inside the Amazon and propagate toward the equator. In January 2005 a squall line propagated from south to north across the entire Amazon basin producing widespread forest tree mortality and contributed to the elevated mortality observed that year. Over the Manaus region (3.4 x104 km2), disturbed forest patches generated by the squall produced a mortality of 0.3-0.5 million trees, equivalent to 30% of the observed annual deforestation reported in 2005 over the same area. The elevated mortality observed in the Central Amazon in 2005 is unlikely to be related to the 2005 Amazon drought since drought did not affect Central or Eastern Amazonia. Assuming a similar rate of forest mortality across the basin, the squall line could have potentially produced tree mortality estimated at 542 ± 121 million trees, equivalent to 23% of the mean annual biomass accumulation estimated for these forests. Our results highlight the vulnerability of Amazon trees to wind-driven mortality associated with convective storms. This vulnerability is likely to increase in a warming climate with models projecting an increase in storm intensity.

  7. Backwater effects in the Amazon River basin of Brazil

    Science.gov (United States)

    Meade, R.H.; Rayol, J.M.; Da Conceicao, S.C.; Natividade, J.R.G.

    1991-01-01

    The Amazon River mainstem of Brazil is so regulated by differences in the timing of tributary inputs and by seasonal storage of water on floodplains that maximum discharges exceed minimum discharges by a factor of only 3. Large tributaries that drain the southern Amazon River basin reach their peak discharges two months earlier than does the mainstem. The resulting backwater in the lowermost 800 km of two large southern tributaries, the Madeira and Puru??s rivers, causes falling river stages to be as much as 2-3 m higher than rising stages at any given discharge. Large tributaries that drain the northernmost Amazon River basin reach their annual minimum discharges three to four months later than does the mainstem. In the lowermost 300-400 km of the Negro River, the largest northern tributary and the fifth largest river in the world, the lowest stages of the year correspond to those of the Amazon River mainstem rather than to those in the upstream reaches of the Negro River. ?? 1991 Springer-Verlag New York Inc.

  8. Influence Deforestation on Hydrological Cycle at Amazon Basin

    Science.gov (United States)

    Cohen, J. C.; Beltrao, J.; Gandu, A. W.

    2007-05-01

    The last three decades, the Amazon Basin has been affected for the occupation with consequence large deforestation. The principal area deforested is located from Maranhao state to Rondonia state. This area is common called "Arc Deforestation", and representing the transition between two important Brazilian ecosystems, Amazon Forest and Savanna Region. Theses ecosystems have precious biodiversity, and it has population about 10.331.000. The objective of this work was to evaluate the impact of arc deforestation on the hydrological cycle at Amazon basin, using BRAMS (Brazilian developments on the Regional Atmospheric Modeling System) including a model of dynamic vegetation, called GEMTM (General Energy and Mass Transport Model). In this study, numerical simulations were performed with a high spatial resolution regional model that allows capture some mesoscale aspects associated to the land used, topography, coastlines and large rivers. In order to predict the impact of the arc deforestation over the hydrological cycle, it was run two model simulations, conducted over a one-year period. In the first simulation, designated "control", it was used the scenarios derived from Soares Filho (2002), for the year 2002, in governance situation. In the second simulation called "deforestation", it was used the scenarios for the 2050, derived from results of Soares-Filho with governance, too. The higher-resolution regional modeling revealed important features of the deforestation process, displaying some associated mesoscale effects that are not typically represented in similar Global Circulation Model simulations. Near coastal zones and along large rivers, deforestation resulted in reduced precipitation. However, it was predicted increased precipitation over mountainous areas, especially on mountain slopes facing river valleys. Then, these higher-resolution simulations showed that, in general, orography, coastline profile and large river distribution play important roles in

  9. Estimation of the evapotranspiration in the Amazon Basin

    International Nuclear Information System (INIS)

    The establishment of a water balance for the Amazon Basin constitutes a problem of difficult solution, not only on the account of its extension and characteristics, but also for lack of sufficient meteorological and hydrological data. In an attempt to estimate the magnitude of the main components of the water balance, a study was made with data from the Brazilian Amazon Region and from some observation stations in other countries. An energy balance was made and based on this balance the water balance of the region was established, having the Penman method been adapted to forest conditions. The data obtained indicate that 90% of the evaportranspiration is due to the energy balance. The evaportranspiration in this area should be very close to the potential evaportranspiration, and the average found was of the order of 4mm/day, i.e., 1460mm/year. As a first approximation it was found that the Amazon Basin system receives 14,4X1012m3 water/year through precipitation, this total being balanced by a surface discharge of 5,5 x1012m3 /year and an evaportranspiration of 8,9x1012m3/year. Since transpiration by plants represents 61,8% of the water balance, all seems to indicate that intensive deforestation shall bring about alterations of the hydrological cycle

  10. Rickettsial Disease in the Peruvian Amazon Basin.

    Science.gov (United States)

    Kocher, Claudine; Morrison, Amy C; Leguia, Mariana; Loyola, Steev; Castillo, Roger M; Galvez, Hugo A; Astete, Helvio; Flores-Mendoza, Carmen; Ampuero, Julia S; Bausch, Daniel G; Halsey, Eric S; Cespedes, Manuel; Zevallos, Karine; Jiang, Ju; Richards, Allen L

    2016-07-01

    Using a large, passive, clinic-based surveillance program in Iquitos, Peru, we characterized the prevalence of rickettsial infections among undifferentiated febrile cases and obtained evidence of pathogen transmission in potential domestic reservoir contacts and their ectoparasites. Blood specimens from humans and animals were assayed for spotted fever group rickettsiae (SFGR) and typhus group rickettsiae (TGR) by ELISA and/or PCR; ectoparasites were screened by PCR. Logistic regression was used to determine associations between patient history, demographic characteristics of participants and symptoms, clinical findings and outcome of rickettsial infection. Of the 2,054 enrolled participants, almost 2% showed evidence of seroconversion or a 4-fold rise in antibody titers specific for rickettsiae between acute and convalescent blood samples. Of 190 fleas (Ctenocephalides felis) and 60 ticks (Rhipicephalus sanguineus) tested, 185 (97.4%) and 3 (5%), respectively, were positive for Rickettsia spp. Candidatus Rickettsia asemboensis was identified in 100% and 33% of the fleas and ticks tested, respectively. Collectively, our serologic data indicates that human pathogenic SFGR are present in the Peruvian Amazon and pose a significant risk of infection to individuals exposed to wild, domestic and peri-domestic animals and their ectoparasites.

  11. Rickettsial Disease in the Peruvian Amazon Basin.

    Science.gov (United States)

    Kocher, Claudine; Morrison, Amy C; Leguia, Mariana; Loyola, Steev; Castillo, Roger M; Galvez, Hugo A; Astete, Helvio; Flores-Mendoza, Carmen; Ampuero, Julia S; Bausch, Daniel G; Halsey, Eric S; Cespedes, Manuel; Zevallos, Karine; Jiang, Ju; Richards, Allen L

    2016-07-01

    Using a large, passive, clinic-based surveillance program in Iquitos, Peru, we characterized the prevalence of rickettsial infections among undifferentiated febrile cases and obtained evidence of pathogen transmission in potential domestic reservoir contacts and their ectoparasites. Blood specimens from humans and animals were assayed for spotted fever group rickettsiae (SFGR) and typhus group rickettsiae (TGR) by ELISA and/or PCR; ectoparasites were screened by PCR. Logistic regression was used to determine associations between patient history, demographic characteristics of participants and symptoms, clinical findings and outcome of rickettsial infection. Of the 2,054 enrolled participants, almost 2% showed evidence of seroconversion or a 4-fold rise in antibody titers specific for rickettsiae between acute and convalescent blood samples. Of 190 fleas (Ctenocephalides felis) and 60 ticks (Rhipicephalus sanguineus) tested, 185 (97.4%) and 3 (5%), respectively, were positive for Rickettsia spp. Candidatus Rickettsia asemboensis was identified in 100% and 33% of the fleas and ticks tested, respectively. Collectively, our serologic data indicates that human pathogenic SFGR are present in the Peruvian Amazon and pose a significant risk of infection to individuals exposed to wild, domestic and peri-domestic animals and their ectoparasites. PMID:27416029

  12. Rickettsial Disease in the Peruvian Amazon Basin

    Science.gov (United States)

    Kocher, Claudine; Morrison, Amy C.; Leguia, Mariana; Loyola, Steev; Castillo, Roger M.; Galvez, Hugo A.; Astete, Helvio; Flores-Mendoza, Carmen; Ampuero, Julia S.; Bausch, Daniel G.; Halsey, Eric S.; Cespedes, Manuel; Zevallos, Karine; Jiang, Ju; Richards, Allen L.

    2016-01-01

    Using a large, passive, clinic-based surveillance program in Iquitos, Peru, we characterized the prevalence of rickettsial infections among undifferentiated febrile cases and obtained evidence of pathogen transmission in potential domestic reservoir contacts and their ectoparasites. Blood specimens from humans and animals were assayed for spotted fever group rickettsiae (SFGR) and typhus group rickettsiae (TGR) by ELISA and/or PCR; ectoparasites were screened by PCR. Logistic regression was used to determine associations between patient history, demographic characteristics of participants and symptoms, clinical findings and outcome of rickettsial infection. Of the 2,054 enrolled participants, almost 2% showed evidence of seroconversion or a 4-fold rise in antibody titers specific for rickettsiae between acute and convalescent blood samples. Of 190 fleas (Ctenocephalides felis) and 60 ticks (Rhipicephalus sanguineus) tested, 185 (97.4%) and 3 (5%), respectively, were positive for Rickettsia spp. Candidatus Rickettsia asemboensis was identified in 100% and 33% of the fleas and ticks tested, respectively. Collectively, our serologic data indicates that human pathogenic SFGR are present in the Peruvian Amazon and pose a significant risk of infection to individuals exposed to wild, domestic and peri-domestic animals and their ectoparasites. PMID:27416029

  13. Branch xylem density variations across the Amazon Basin

    Directory of Open Access Journals (Sweden)

    S. Patiño

    2009-04-01

    Full Text Available Xylem density is a physical property of wood that varies between individuals, species and environments. It reflects the physiological strategies of trees that lead to growth, survival and reproduction. Measurements of branch xylem density, ρx, were made for 1653 trees representing 598 species, sampled from 87 sites across the Amazon basin. Measured values ranged from 218 kg m−3 for a Cordia sagotii (Boraginaceae from Mountagne de Tortue, French Guiana to 1130 kg m−3 for an Aiouea sp. (Lauraceae from Caxiuana, Central Pará, Brazil. Analysis of variance showed significant differences in average ρx across regions and sampled plots as well as significant differences between families, genera and species. A partitioning of the total variance in the dataset showed that species identity (family, genera and species accounted for 33% with environment (geographic location and plot accounting for an additional 26%; the remaining "residual" variance accounted for 41% of the total variance. Variations in plot means, were, however, not only accountable by differences in species composition because xylem density of the most widely distributed species in our dataset varied systematically from plot to plot. Thus, as well as having a genetic component, branch xylem density is a plastic trait that, for any given species, varies according to where the tree is growing in a predictable manner. Within the analysed taxa, exceptions to this general rule seem to be pioneer species belonging for example to the Urticaceae whose branch xylem density is more constrained than most species sampled in this study. These patterns of variation of branch xylem density across Amazonia suggest a large functional diversity amongst Amazonian trees which is not well understood.

  14. Deforestation, floodplain dynamics, and carbon biogeochemistry in the Amazon Basin

    Science.gov (United States)

    Bryan, M. L.; Dunne, T.; Richey, J.; Melack, J.; Simonett, D. S.; Woodwell, G.

    1984-01-01

    Three aspects of the physical geographic environment of the Amazon Basin are considered: (1) deforestation and reforestation, (2) floodplain dynamics, and (3) fluvial geomorphology. Three independent projects are coupled in this experiment to improve the in-place research and to ensure that the Shuttle Imaging Radar-B (SIR-B) experiment stands on a secure base of ongoing work. Major benefits to be obtained center on: (1) areal and locational information, (2) data from various depression angles, and (3) digital radar signatures. Analysis will be conducted for selected sites to define how well SIR-B data can be used for: (1) definition of extent and location of deforestation in a tropical moist forest, (2) definition and quantification of the nature of the vegetation and edaphic conditions on the (floodplain) of the Amazon River, and (3) quantification of the accuracy with which the geometry and channel shifting of the Amazon River may be mapped using SIR-B imagery in conjunction with other remote sensing data.

  15. Artisanal fisheries of the Xingu River basin in Brazilian Amazon.

    Science.gov (United States)

    Isaac, V J; Almeida, M C; Cruz, R E A; Nunes, L G

    2015-08-01

    The present study characterises the commercial fisheries of the basin of the Xingu River, a major tributary of the Amazon River, between the towns of Gurupá (at the mouth of the Amazon) and São Félix do Xingu. Between April, 2012, and March, 2014, a total of 23,939 fishing trips were recorded, yielding a total production of 1,484 tons of fish, harvested by almost three thousand fishers. The analysis of the catches emphasizes the small-scale and artisanal nature of the region's fisheries, with emphasis on the contribution of the motorised canoes powered by "long-tail" outboard motors. Larger motorboats operate only at the mouth of the Xingu and on the Amazon. Peacock bass (Cichla spp.), croakers (Plagioscion spp.), pacu (a group containing numerous serrasalmid species), aracu (various anostomids), and curimatã (Prochilodus nigricans) together contributed more than 60% of the total catch. Mean catch per unit effort was 18 kg/fisher-1.day-1, which varied among fishing methods (type of vessel and fishing equipment used), river sections, and time of the year. In most cases, yields varied little between years (2012 and 2013). The technical database provided by this study constitutes an important resource for the regulation of the region's fisheries, as well as for the evaluation of future changes resulting from the construction of the Belo Monte dam on the Xingu River.

  16. Erosion of particulate organic material from an Andean river and its delivery to the Amazon Basin

    Science.gov (United States)

    Clark, Kathryn; Hilton, Robert; West, A. Joshua; Robles Caceres, Arturo; Grocke, Darren; Marthews, Toby; Asner, Greg; New, Mark; Mahli, Yadvinder

    2016-04-01

    Organic carbon and nutrients discharged by mountainous rivers can play an important role in biogeochemical cycles from regional to global scales. The eastern Andes host productive forests on steep, rapidly eroding slopes, a combination that is primed to deliver sediment, carbon and nutrients to the lowland Amazon River. We quantify clastic sediment and particulate organic carbon (POC) discharge for the Kosñipata River, Peru, an Andean tributary of the Madre de Dios River, using suspended sediment samples and discharge measurements over one year at two gauging stations. Calculations of sediment yield on the basis of this data suggest that the Madre de Dios basin may have erosion rates ˜10 times greater than the Amazon Basin average. The total POC yield over the sampling period was up to five times higher than the yield in the lowland Amazon Basin, with most POC (70-80%) exported between December and March in the wet season. We use radiocarbon, stable C isotopes and C/N ratios to distinguish between the erosion and discharge of POC from sedimentary rocks (petrogenic POC) and POC eroded from the modern terrestrial biosphere, from vegetation and soil (biospheric POC). We find that biospheric POC discharge was significantly enhanced during flood events, over that of clastic sediment and petrogenic POC. The ultimate fate of the eroded POC may play a central role in the net carbon budget of Andean forest. In these forests, net productivity minus heterotrophic respiration is close to zero at the scale of forest plots, and the erosion of biospheric POC by this Andean river is sufficiently rapid that its fate downstream (sedimentary burial/preservation versus oxidation/degradation) may determine whether the mountain forest is a carbon sink or source to the atmosphere. In addition, the measured discharge of petrogenic POC suggests that fluxes from the Andes may be considerably higher than measured downstream in the Madeira River. If this petrogenic POC is oxidised rather

  17. Simulating hydrologic and hydraulic processes throughout the Amazon River Basin

    Science.gov (United States)

    Beighley, R.E.; Eggert, K.G.; Dunne, T.; He, Y.; Gummadi, V.; Verdin, K.L.

    2009-01-01

    Presented here is a model framework based on a land surface topography that can be represented with various degrees of resolution and capable of providing representative channel/floodplain hydraulic characteristics on a daily to hourly scale. The framework integrates two models: (1) a water balance model (WBM) for the vertical fluxes and stores of water in and through the canopy and soil layers based on the conservation of mass and energy, and (2) a routing model for the horizontal routing of surface and subsurface runoff and channel and floodplain waters based on kinematic and diffusion wave methodologies. The WBM is driven by satellite-derived precipitation (TRMM_3B42) and air temperature (MOD08_M3). The model's use of an irregular computational grid is intended to facilitate parallel processing for applications to continental and global scales. Results are presented for the Amazon Basin over the period Jan 2001 through Dec 2005. The model is shown to capture annual runoff totals, annual peaks, seasonal patterns, and daily fluctuations over a range of spatial scales (>1, 000 to basin-wide total water storage changes in the Amazon vary by approximately +/-5 to 10 cm, and the fractional components accounting for these changes are: root zone soil moisture (20%), subsurface water being routed laterally to channels (40%) and channel/floodplain discharge (40%). Annual variability in monthly water storage changes by +/-2.5 cm is likely due to 0D5 to 1 month variability in the arrival of significant rainfall periods throughout the basin. Copyright ?? 2009 John Wiley & Sons, Ltd.

  18. Sensitivity of Regional Climate to Deforestation in the Amazon Basin

    Science.gov (United States)

    Eltahir, Elfatih A. B.; Bras, Rafael L.

    1994-01-01

    The deforestation results in several adverse effect on the natural environment. The focus of this paper is on the effects of deforestation on land-surface processes and regional climate of the Amazon basin. In general, the effect of deforestation on climate are likely to depend on the scale of the defrosted area. In this study, we are interested in the effects due to deforestation of areas with a scale of about 250 km. Hence, a meso-scale climate model is used in performing numerical experiments on the sensitivity of regional climate to deforestation of areas with that size. It is found that deforestation results in less net surface radiation, less evaporation, less rainfall, and warmer surface temperature. The magnitude of the of the change in temperature is of the order 0.5 C, the magnitudes of the changes in the other variables are of the order of IO%. In order to verify some of he results of the numerical experiments, the model simulations of net surface radiation are compared to recent observations of net radiation over cleared and undisturbed forest in the Amazon. The results of the model and the observations agree in the following conclusion: the difference in net surface radiation between cleared and undisturbed forest is, almost, equally partioned between net solar radiation and net long-wave radiation. This finding contributes to our understanding of the basic physics in the deforestation problem.

  19. Iron cycling in the Amazon River Basin: the isotopic perspective

    Science.gov (United States)

    Poitrasson, Franck; Vieira, Lucieth; Mulholland, Daniel; Seyler, Patrick; Sondag, Francis; Allard, Thierry

    2014-05-01

    With the global climate change and increasing anthropic pressure on nature, it is important to find new indicators of the response of complex systems like the Amazon River Basin. In particular, new tracers like iron isotopes may tell us much on processes such as the chemical exchanges between rivers, soils and the biosphere. Pioneering studies revealed that for some river waters, large δ57Fe fractionations are observed between the suspended and dissolved load (Bergquist and Boyle, 2006), and isotopic variations were also recognized on the suspended matter along the hydrological cycle (Ingri et al., 2006). On land, soil studies from various locations have shown that δ57Fe signatures depend mostly on the weathering regime (Fantle and DePaolo, 2004; Emmanuel et al., 2005; Wiederhold et al., 2007; Poitrasson et al., 2008). It thus seems that Fe isotopes could become an interesting new tracer of the exchanges between soils, rivers and the biosphere. We therefore conducted Fe isotope surveys through multidisciplinary field missions on rivers from the Amazon Basin. It was confirmed that acidic, organic-rich black waters show strong Fe isotope fractionation between particulate and dissolved loads. Furthermore, this isotopic fractionation varies along the hydrological cycle, like previously uncovered in boreal waters suspended matter. In contrast, unfiltered waters show very little variation with time. It was also found that Fe isotopes remain a conservative tracer even in the case of massive iron loss during the mixing of chemically contrasted waters such as the Negro and Solimões tributaries of the Amazon River. Given that >95% of the Fe from the Amazon River is carried as detrital materials, our results lead to the conclusion that the Fe isotope signature delivered to the Atlantic Ocean is undistinguishable from the continental crust value, in contrast to previous inferences. The results indicate that Fe isotopes in rivers represent a promising indicator of the

  20. Chemodiversity of dissolved organic matter in the Amazon Basin

    Science.gov (United States)

    Gonsior, Michael; Valle, Juliana; Schmitt-Kopplin, Philippe; Hertkorn, Norbert; Bastviken, David; Luek, Jenna; Harir, Mourad; Bastos, Wanderley; Enrich-Prast, Alex

    2016-07-01

    Regions in the Amazon Basin have been associated with specific biogeochemical processes, but a detailed chemical classification of the abundant and ubiquitous dissolved organic matter (DOM), beyond specific indicator compounds and bulk measurements, has not yet been established. We sampled water from different locations in the Negro, Madeira/Jamari and Tapajós River areas to characterize the molecular DOM composition and distribution. Ultrahigh-resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) combined with excitation emission matrix (EEM) fluorescence spectroscopy and parallel factor analysis (PARAFAC) revealed a large proportion of ubiquitous DOM but also unique area-specific molecular signatures. Unique to the DOM of the Rio Negro area was the large abundance of high molecular weight, diverse hydrogen-deficient and highly oxidized molecular ions deviating from known lignin or tannin compositions, indicating substantial oxidative processing of these ultimately plant-derived polyphenols indicative of these black waters. In contrast, unique signatures in the Madeira/Jamari area were defined by presumably labile sulfur- and nitrogen-containing molecules in this white water river system. Waters from the Tapajós main stem did not show any substantial unique molecular signatures relative to those present in the Rio Madeira and Rio Negro, which implied a lower organic molecular complexity in this clear water tributary, even after mixing with the main stem of the Amazon River. Beside ubiquitous DOM at average H / C and O / C elemental ratios, a distinct and significant unique DOM pool prevailed in the black, white and clear water areas that were also highly correlated with EEM-PARAFAC components and define the frameworks for primary production and other aspects of aquatic life.

  1. Green Leaf Volatile Emissions during High Temperature and Drought Stress in a Central Amazon Rainforest

    Directory of Open Access Journals (Sweden)

    Kolby J. Jardine

    2015-09-01

    Full Text Available Prolonged drought stress combined with high leaf temperatures can induce programmed leaf senescence involving lipid peroxidation, and the loss of net carbon assimilation during early stages of tree mortality. Periodic droughts are known to induce widespread tree mortality in the Amazon rainforest, but little is known about the role of lipid peroxidation during drought-induced leaf senescence. In this study, we present observations of green leaf volatile (GLV emissions during membrane peroxidation processes associated with the combined effects of high leaf temperatures and drought-induced leaf senescence from individual detached leaves and a rainforest ecosystem in the central Amazon. Temperature-dependent leaf emissions of volatile terpenoids were observed during the morning, and together with transpiration and net photosynthesis, showed a post-midday depression. This post-midday depression was associated with a stimulation of C5 and C6 GLV emissions, which continued to increase throughout the late afternoon in a temperature-independent fashion. During the 2010 drought in the Amazon Basin, which resulted in widespread tree mortality, green leaf volatile emissions (C6 GLVs were observed to build up within the forest canopy atmosphere, likely associated with high leaf temperatures and enhanced drought-induced leaf senescence processes. The results suggest that observations of GLVs in the tropical boundary layer could be used as a chemical sensor of reduced ecosystem productivity associated with drought stress.

  2. The Amazon Tall Tower Observatory (ATTO in the remote Amazon Basin: overview of first results from ecosystem ecology, meteorology, trace gas, and aerosol measurements

    Directory of Open Access Journals (Sweden)

    M. O. Andreae

    2015-04-01

    Full Text Available The Amazon Basin plays key roles in the carbon and water cycles, climate change, atmospheric chemistry, and biodiversity. It already has been changed significantly by human activities, and more pervasive change is expected to occur in the next decades. It is therefore essential to establish long-term measurement sites that provide a baseline record of present-day climatic, biogeochemical, and atmospheric conditions and that will be operated over coming decades to monitor change in the Amazon region as human perturbations increase in the future. The Amazon Tall Tower Observatory (ATTO has been set up in a pristine rain forest region in the central Amazon Basin, about 150 km northeast of the city of Manaus. An ecological survey including a biodiversity assessment has been conducted in the forest region surrounding the site. Two 80 m towers have been operated at the site since 2012, and a 325 m tower is nearing completion in mid-2015. Measurements of micrometeorological and atmospheric chemical variables were initiated in 2012, and their range has continued to broaden over the last few years. The meteorological and micrometeorological measurements include temperature and wind profiles, precipitation, water and energy fluxes, turbulence components, soil temperature profiles and soil heat fluxes, radiation fluxes, and visibility. A tree has been instrumented to measure stem profiles of temperature, light intensity, and water content in cryptogamic covers. The trace gas measurements comprise continuous monitoring of carbon dioxide, carbon monoxide, methane, and ozone at 5 to 8 different heights, complemented by a variety of additional species measured during intensive campaigns (e.g., VOC, NO, NO2, and OH reactivity. Aerosol optical, microphysical, and chemical measurements are made above the canopy as well as in the canopy space. They include light scattering and absorption, aerosol fluorescence, number and volume size distributions, chemical

  3. The recent extreme hydrological events in the Western Amazon Basin: The role of the Pacific and Atlantic Oceans

    Science.gov (United States)

    Espinoza, J.; Ronchail, J.; Guyot, J.; Santini, W.; Lavado, W.; Ore-Hybam Observatory

    2013-05-01

    The Peruvian Amazonas River, the main western tributary of the Amazon basin, has a huge drainage (750 000 km2, 50% of which lies in the Andes) and a mean discharge estimated in 32 000 m3/s, which correspond to 15% of the Amazon discharge at the estuary. Recently, in a context of significant discharge diminution during the low-water season (1970-2012), severe hydrological events, as intense droughts and floods, have been reported in the Peruvian Amazonas River. As they have not been always observed in other regions of the Amazon basin and because they have strong impacts on vulnerable riverside residents, we shall focus on the origin and the predictability of the western Amazon extremes, providing a review of the main findings about the climate features during recent extreme hydrological events in western Amazon. While the lowest discharge value was observed in September 2010 (8 300 m3/s) at the hydrological Tamshiyacu station (near to Iquitos city), a rapid transition toward a high discharge was noticed in April 2011 (45 000 m3/s). Finally, in April 2012, during the on going high waters period, the Amazonas River is experimenting its historical highest discharge (55 000 m3/s). Our work is based on several datasets including in-situ discharge and rainfall information from ORE-HYBAM observatory. Extreme droughts (1995, 2005 and 2010) are generally associated with positive SST anomalies in the tropical North Atlantic and weak trade winds and water vapor transport toward the western Amazon, which, in association with increased subsidence over central and southern Amazon, explain the lack of rainfall and very low discharge values. But, in 1998, toward the end of the 1997-98 El Niño event, the drought has been more likely related to an anomalous divergence of water vapor in the western Amazon that is characteristic of a warm event in the Pacific. The years with a rapid transition form low waters to very high floods (e.g. September 2010 to April 2011) are characterized

  4. Forest response to increased disturbance in the Central Amazon and comparison to Western Amazonian forests

    Directory of Open Access Journals (Sweden)

    J. A. Holm

    2014-05-01

    Full Text Available Uncertainties surrounding vegetation response to increased disturbance rates associated with climate change remains a major global change issue for Amazon forests. Additionally, turnover rates computed as the average of mortality and recruitment rates in the Western Amazon basin are doubled when compared to the Central Amazon, and notable gradients currently exist in specific wood density and aboveground biomass (AGB between these two regions. This study investigates the extent to which the variation in disturbance regimes contributes to these regional gradients. To address these issues, we evaluated disturbance-recovery processes under two scenarios of increased disturbance rates in a complex Central Amazon forest using first ZELIG-TROP, a dynamic vegetation gap model which we calibrated using long-term inventory data, and second using the Community Land Model (CLM, a global land surface model that is part of the Community Earth System Model (CESM. Upon doubling the mortality rate in the Central Amazon to mirror the natural disturbance regime in the Western Amazon of ∼2% mortality, at steady-state, AGB significantly decreased by 41.9% and there was no significant difference between the modeled AGB of 104 Mg C ha−1 and empirical AGB from the western Amazon datasets of 107 Mg C ha−1. We confirm that increases in natural disturbance rates in the Central Amazon will result in terrestrial carbon loss associated with higher turnover. However, different processes were responsible for the reductions in AGB between the models and empirical datasets. We observed that with increased turnover, the subsequent decrease in wood density drives the reduction in AGB in empirical datasets. However, decrease in stand basal area was the driver of the drop in AGB in ZELIG-TROP, and decreased leaf area index (LAI was the driver in CLM. Further comparisons found that stem density, specific wood density, and basal area growth rates differed between the two

  5. Micrometeorological Conditions at the ATTO - Site in the Amazon Basin

    Science.gov (United States)

    Tsokankunku, Anywhere; Sörgel, Matthias; Acevedo, Otávio C.; Araùjo, Alessandro; Berger, Martina; de Abreu Sá, Leonardo D.; de Oliveira Sá, Marta; Dias, Nelson L.; Dlugi, Ralph; Manzi, Antonio O.; Oliveira, Pablo E. S.; Zelger, Michael

    2016-04-01

    The ATTO site is located in a pristine rainforest environment in the Amazon basin about 150 km north east of Manaus. The site is currently equipped with two walk-up towers (325 m and 80 m) and an 80 m high mast. The canopy height is about 35 m. A detailed description of the site and the ongoing measurements is given in the overview paper by Andreae et al. (2015). The 325 m tower was completed in 2015 and will be equipped in 2016. The 80 m walk-up tower is operational since 2012 with a full set of micrometeorological measurements (e.g. wind and temperature profile, radiation, and a few levels for flux measurements). Measurements of vertical profiles of wind velocity components, temperature, humidity, and energy fluxes, together with 3d sonic anemometer measurements at 150 m on the ATTO tower, are analysed to determine characteristics of momentum, heat and water vapour exchange. In addition, the day time influences of secondary circulation on energy fluxes is described, together with the interaction of these circulations with cloud development. The diurnal cycle of stability and the onset and development of convection is shown to be strongly dependent on the onset of cloud formation. Implications on trace gas transport are discussed.

  6. Isotope geochemistry of the Amazon Basin: A reconnaissance

    Science.gov (United States)

    Longinelli, A.; Edmond, J. M.

    1983-04-01

    On the transects of the Amazon River made by the Alpha Helix in 1976 and 1977, an extensive suite of samples was collected for isotopic analyses. The water isotopes (18O/16O, D/H) were determined in atmospheric water vapour and in river, rain, and leaf waters. 13C/12C ratios were measured in the dissolved and atmospheric CO2. Determinations were made of 34S/32S and oxygen isotopes in dissolved sulphate. The effect of `continentality' on the water isotopes is minor reflecting the large scale recycling by evapotranspiration from the huge area of forest within the basin. Variations in the isotopic abundances between 1976 (June-July, dry season) and 1977 (May-June, end of wet season) are consistent with the changes in meteorological conditions. The isotopic composition of the CO2, both atmospheric and dissolved, is dominated by biological effects. In 1976 the dissolved CO2 showed downstream variations from -14‰ at Iquitos in Peru to -22‰ in the lower reaches. In 1977, no systematic trend was apparent, the data ranging around -19‰. The values for atmospheric CO2 decrease inland from marine values at the mouth to around -15‰ at Manaus. During the dry season (1976) the values in the interior, western basin were homogeneous at -20‰. In the wet season there were considerable variations reflecting atmospheric instabilities with the average value being about -13‰. The sulphur isotopic composition of the dissolved sulphate is remarkably uniform at around 7‰. In 1977 the 18O values in the sulphate decreased systematically downstream from 8‰ in Peru to 3‰ at the mouth, consistent with a progressive, redox-mediated exchange with water and dissolved oxygen. In 1977 the values increased to over 11‰, apparently indicating exchange with a highly fractionated reservoir of dissolved oxygen perhaps in the semireducing environment of the flood plain lakes.

  7. Ecological diversity of Trypanosoma cruzi transmission in the Amazon basin. The main scenaries in the Brazilian Amazon.

    Science.gov (United States)

    Coura, J R; Junqueira, A C V

    2015-11-01

    The ecological diversity of Trypanosoma cruzi transmission in the Brazilian Amazon region is directly interlinked with the parasite's extensive reservoir, composed of 33 species of wild mammals within the following orders: Marsupialia, Chiroptera, Rodentia, Xenarthra, Carnivora and Primates; and of 16 species of wild triatomines, of which ten may be infected with T. cruzi. Four scenarios for the diversity of T. cruzi transmission in the Brazilian Amazon region are evident: (i) T. cruzi transmission between vectors and wild mammals, which is characterized as a wild enzooty encompassing the entire Amazon basin; (ii) accidental T. cruzi transmission from vectors and wild mammals to humans, when they invade the wild ecotope or when these vectors and wild mammals invade human homes; (iii) occupational Chagas disease among piassava (Leopoldinia piassaba) palm fiber gatherers, transmitted by the vector Rhodnius brethesi, for which these palm trees are the specific ecotope; (IV) oral T. cruzi transmission to humans through food contamination, particularly in juices from plants such as assai, which today is considered to be endemic in the Brazilian Amazon region, with more than 1500 cases notified.

  8. Validation and analysis of MOPITT CO observations of the Amazon Basin

    Science.gov (United States)

    Deeter, M. N.; Martínez-Alonso, S.; Gatti, L. V.; Gloor, M.; Miller, J. B.; Domingues, L. G.; Correia, C. S. C.

    2016-08-01

    We analyze satellite retrievals of carbon monoxide from the MOPITT (Measurements of Pollution in the Troposphere) instrument over the Amazon Basin, focusing on the MOPITT Version 6 "multispectral" retrieval product (exploiting both thermal-infrared and near-infrared channels). Validation results based on in situ vertical profiles measured between 2010 and 2013 are presented for four sites in the Amazon Basin. Results indicate a significant negative bias in retrieved lower-tropospheric CO concentrations. The possible influence of smoke aerosol as a source of retrieval bias is investigated using collocated Aerosol Robotic Network (AERONET) aerosol optical depth (AOD) measurements at two sites but does not appear to be significant. Finally, we exploit the MOPITT record to analyze both the mean annual cycle and the interannual variability of CO over the Amazon Basin since 2002.

  9. Source area and seasonal Sr-87/Sr-86 variations in rivers of the Amazon basin

    OpenAIRE

    R. V. Santos; Sondag, Francis; Cochonneau, Gérard; Lagane, C.; Brunet, P.; Hattingh, K.; Chaves, J. G. S.

    2015-01-01

    We report the results of a detailed study of dissolved Sr isotopes in the Solimoes and Beni-Madeira Rivers of the Amazon basin. This study developed data collected over 8years indicating large spatial and temporal variations in dissolved Sr isotopes among the rivers of the Amazon basin. The large Sr-87/Sr-86 variations were found to be correlated with the geology of the source areas of the suspended sediments. The Beni-Madeira River displays a high average Sr-87/Sr-86 ratio and large Sr-87/Sr...

  10. Exploring the Geomorphology of the Amazon's Planalto and Understanding the Origin of the Modern Amazon Basin with Imaging Radar:

    Science.gov (United States)

    Islam, R.; McDonald, K. C.; Azarderakhsh, M.; Campbell, K.; Cracraft, J.; Carnaval, A. C.

    2015-12-01

    The Amazon basin is a biodiversity biome and plays a significant role into shaping the earth's climate, ocean and atmospheric gases. Understanding the history of the formation of the basin is essential to our understanding of the region's biodiversity loss and response to climate change. Ancient River channels in lowland Amazonia exhibit right angle branching structures as well as intricately intertwined channels. Past research has attributed these characteristic as a result of subsurface faults but makes it difficult to validate this augment due to dense vegetation and sedimentation. We seek to employ remote sensing techniques for examining geomorphological features and the relationship to evolutionary processes that shaped biodiversity in the modern Amazon River Basin. We utilize UAVSAR imagery gathered from the NASA/JPL airborne imaging radar over the Planalto, in the Madre de Dios region of Southeastern Peru in an assessment of the underlying geomorphology, its relationship to the current distribution of vegetation, and geologic processes through deep time. In the late Neogene, the Amazonian lowlands comprised either a series of independent basins or a single sedimentary basin. The Amazonian Planalto is variously described as either erosional surface or a surface of deposition. We employ UAVSAR data collection to assess (1) the utility of these radar data for use in identifying associated geomorphologic features, and (2) UAVSAR's utility in aiding interpretation of ALOS PALSAR and STRM datasets to support a basin-wide characterization. We derive maps of river networks using a canny based edge detection method applied on the UAVSAR backscatter images. We develop an algorithm, which separates the river networks into various catchments based on connected component and then calculates angles at each branch point. We then assess distribution of right angle branching structure throughout the entire region. The results of the analysis will have a major impact on

  11. Geology, Soils and Basin-wide variations in Amazon Forest Structure and function

    Science.gov (United States)

    Quesada, Carlos Alberto; Phillips, Oliver; Lopes-Gonzales, Gabriela; Lloyd, Jon; Rainfor Team

    2015-04-01

    Forest productivity, tree turnover time and above ground biomass vary across the Amazon Basin in an east-west gradient in a pattern which coincides with variations in soil nutrient availability and geology. Forest productivity rates are higher on the most nutrient rich soils close to the Andes while is lower in the ancient, highly weathered soils of central Amazonia. On the other hand above ground biomass is lower in the most productive forests and higher on the least, this being a consequence of higher tree turnover rates in the forests over less weathered and nutrient rich soils. Major geological events have influenced Amazonian soil characteristics profoundly and play an important role in explaining Basin-wide variations in forest biomass, growth and stem turnover rates. Here we show how geology and soil development combine to shape the functioning of Amazonian forests and its carbon stocks and fluxes. To assess the importance of edaphic properties in affect forest structure and dynamics, soil samples were collected in a total of 154 different forest plots across nine different Amazonian countries. Samples were analyzed for exchangeable cations, C, N, pH with various P fractions and soil physical properties also determined. Overall, forest structure and dynamics were found to be strongly and quantitatively related to edaphic conditions.

  12. Spectral dependence of aerosol light absorption over the Amazon Basin

    Science.gov (United States)

    Rizzo, L. V.; Correia, A. L.; Artaxo, P.; Procópio, A. S.; Andreae, M. O.

    2011-09-01

    In this study, we examine the spectral dependence of aerosol absorption at different sites and seasons in the Amazon Basin. The analysis is based on measurements performed during three intensive field experiments at a pasture site (Fazenda Nossa Senhora, Rondônia) and at a primary forest site (Cuieiras Reserve, Amazonas), from 1999 to 2004. Aerosol absorption spectra were measured using two Aethalometers: a 7-wavelength Aethalometer (AE30) that covers the visible (VIS) to near-infrared (NIR) spectral range, and a 2-wavelength Aethalometer (AE20) that measures absorption in the UV and in the NIR. As a consequence of biomass burning emissions, about 10 times greater absorption values were observed in the dry season in comparison to the wet season. Power law expressions were fitted to the measurements in order to derive the absorption Ångström exponent, defined as the negative slope of absorption versus wavelength in a log-log plot. At the pasture site, about 70 % of the absorption Ångström exponents fell between 1.5 and 2.5 during the dry season, indicating that biomass burning aerosols have a stronger spectral dependence than soot carbon particles. Ångström exponents decreased from the dry to the wet season, in agreement with the shift from biomass burning aerosols, predominant in the fine mode, to biogenic and dust aerosols, predominant in the coarse mode. The lowest absorption Ångström exponents (90 % of data below 1.5) were observed at the forest site during the dry season. Also, results indicate that low absorption coefficients were associated with low Ångström exponents. This finding suggests that biogenic aerosols from Amazonia have a weaker spectral dependence for absorption than biomass burning aerosols, contradicting our expectations of biogenic particles behaving as brown carbon. In a first order assessment, results indicate a small (<1 %) effect of variations in absorption Ångström exponents on 24-h aerosol forcings, at least in the spectral

  13. Sediment budget in the Ucayali River basin, an Andean tributary of the Amazon River

    OpenAIRE

    W. Santini; Martinez, J. -M.; Espinoza-Villar, R.; G. Cochonneau; Vauchel, P.; Moquet, J.-S.; Baby, P.; Espinoza, J.-C.; Lavado, W.; Carranza, J.; Guyot, J.-L.

    2015-01-01

    Formation of mountain ranges results from complex coupling between lithospheric deformation, mechanisms linked to subduction and surface processes: weathering, erosion, and climate. Today, erosion of the eastern Andean cordillera and sub-Andean foothills supplies over 99% of the sediment load passing through the Amazon Basin. Denudation rates in the upper Ucayali basin are rapid, favoured by a marked seasonality in this region and extreme precipitation cells above sedimentary strata, uplifted...

  14. Exploring the Geomorphology of the Amazon's Planalto with Imaging Radar: Understanding the Origins of the Modern Amazon Basin

    Science.gov (United States)

    McDonald, K. C.; Campbell, K.; Islam, R.; Azarderakhsh, M.; Cracraft, J.

    2013-12-01

    Amazonia is Earth's most iconic center of biological diversity and endemism and, owing to its contributions to global systems ecology, is arguably Earth's most important terrestrial biome . Amazonia includes a vast landscape of mostly lowland rainforest found in Brazil, Peru, Colombia, Ecuador, Bolivia, and Venezuela. It harbors the world's highest species diversity, the largest fresh-water ecosystem in the world, and contributes substantially to shaping the Earth's atmospheric gasses and oceans and consequently its climate. Despite this global importance, we still have an incomplete understanding of how this biodiversity-rich biome developed over time. Knowing its history is crucially important for understanding how the short and long-term effects of biodiversity loss and climate change will impact the region, and the globe, in the future. Hence, we seek to understand the evolutionary and environmental-ecological history of Amazonia over the past 10 million years through a comparative approach that integrates across the disciplines of systematic biology, population biology, ecosystem structure and function, geology, Earth systems modeling and remote sensing, and paleoenvironmental history. During springtime 2013, the NASA/JPL airborne imaging radar, UAVSAR, conducted airborne studies over many regions of South America including portions of the western Amazon basin. We utilize UAVSAR imagery acquired over the Madre de Dios region of southeastern Peru in an assessment of the underlying geomorphology of the Amazon's planalto, its relationship to the current distribution of vegetation, and its relationship to geologic processes through deep time. In the late Neogene, the Amazonian lowlands comprised either a series of independent basins or a single sedimentary basin. The Amazonian planalto is variously described as either an erosional surface or a surface of deposition. We employ UAVSAR data collections to assess (1) the utility of these high quality imaging radar

  15. Mayaro virus infection, Amazon Basin region, Peru, 2010-2013.

    Science.gov (United States)

    Halsey, Eric S; Siles, Crystyan; Guevara, Carolina; Vilcarromero, Stalin; Jhonston, Erik J; Ramal, Cesar; Aguilar, Patricia V; Ampuero, Julia S

    2013-11-01

    During 2010-2013, we recruited 16 persons with confirmed Mayaro virus infection in the Peruvian Amazon to prospectively follow clinical symptoms and serologic response over a 12-month period. Mayaro virus infection caused long-term arthralgia in more than half, similar to reports of other arthritogenic alphaviruses.

  16. Description of Lutzomyia (Trichophoromyia) nautaensis n. sp. (Diptera: Psychodidae) from the Peruvian Amazon Basin.

    Science.gov (United States)

    Fernandez, Roberto; Lopez, Victor; Cardenas, Roldan; Requena, Edwin

    2015-07-01

    A new species of sand fly, which we describe as Lutzomyia (Trichophoromyia) nautaensis n. sp., was collected in the northern Peruvian Amazon Basin. In this region of Peru, cutaneous leishmaniasis is transmitted primarily by anthropophilic sand flies; however, zoophilic sand flies of the subgenus Trichophoromyia may also be incriminated in disease transmission. Detection of Leishmania spp. in Lutzomyia auraensis Mangabeira captured in the southern Peruvian Amazon indicates the potential of this and other zoophilic sand flies for human disease transmission, particularly in areas undergoing urban development. Herein, we describe Lutzomyia (Trichophoromyia) nautaensis n. sp., and report new records of sand flies in Peru. PMID:26335468

  17. Description of Lutzomyia (Trichophoromyia) nautaensis n. sp. (Diptera: Psychodidae) from the Peruvian Amazon Basin.

    Science.gov (United States)

    Fernandez, Roberto; Lopez, Victor; Cardenas, Roldan; Requena, Edwin

    2015-07-01

    A new species of sand fly, which we describe as Lutzomyia (Trichophoromyia) nautaensis n. sp., was collected in the northern Peruvian Amazon Basin. In this region of Peru, cutaneous leishmaniasis is transmitted primarily by anthropophilic sand flies; however, zoophilic sand flies of the subgenus Trichophoromyia may also be incriminated in disease transmission. Detection of Leishmania spp. in Lutzomyia auraensis Mangabeira captured in the southern Peruvian Amazon indicates the potential of this and other zoophilic sand flies for human disease transmission, particularly in areas undergoing urban development. Herein, we describe Lutzomyia (Trichophoromyia) nautaensis n. sp., and report new records of sand flies in Peru.

  18. The size distribution of organic carbon in headwater streams in the Amazon basin.

    Science.gov (United States)

    de Paula, Joana D'Arc; Luizão, Flávio Jesus; Piedade, Maria Teresa Fernandez

    2016-06-01

    Despite the strong representativeness of streams in the Amazon basin, their role in the accumulation of coarse particulate organic carbon (CPOC), fine particulate organic carbon (FPOC), and dissolved organic carbon (DOC) in transport, an important energy source in these environments, is poorly known. It is known that the arboreal vegetation in the Amazon basin is influenced by soil fertility and rainfall gradients, but would these gradients promote local differences in organic matter in headwater streams? To answer this question, 14 low-order streams were selected within these gradients along the Amazon basin, with extensions that varied between 4 and 8 km. The efficiency of the transformation of particulate into dissolved carbon fractions was assessed for each stream. The mean monthly benthic organic matter storage ranged between 1.58 and 9.40 t ha(-1) month(-1). In all locations, CPOC was the most abundant fraction in biomass, followed by FPOC and DOC. Rainfall and soil fertility influenced the distribution of the C fraction (p = 0.01), showing differentiated particulate organic carbon (POC) storage and DOC transportation along the basin. Furthermore, the results revealed that carbon quantification at the basin level could be underestimated, ultimately influencing the global carbon calculations for the region. This is especially due to the fact that the majority of studies consider only fine particulate organic matter and dissolved organic matter, which represent less than 50 % of the stored and transported carbon in streambeds.

  19. Indications of regional scale groundwater flows in the Amazon Basins: Inferences from results of geothermal studies

    Science.gov (United States)

    Pimentel, Elizabeth T.; Hamza, Valiya M.

    2012-08-01

    The present work deals with determination groundwater flows in the Amazon region, based on analysis of geothermal data acquired in shallow and deep wells. The method employed is based on the model of simultaneous heat transfer by conduction and advection in permeable media. Analysis of temperature data acquired in water wells indicates down flows of groundwaters with velocities in excess of 10-7 m/s at depths less than 300 m in the Amazonas basin. Bottom-hole temperature (BHT) data sets have been used in determining characteristics of fluid movements at larger depths in the basins of Acre, Solimões, Amazonas, Marajó and Barreirinhas. The results of model simulations point to down flow of groundwaters with velocities of the order of 10-8 to 10-9 m/s, at depths of up to 4000 m. No evidence has been found for up flow typical of discharge zones. The general conclusion compatible with such results is that large-scale groundwater recharge systems operate at both shallow and deep levels in all sedimentary basins of the Amazon region. However, the basement rock formations of the Amazon region are relatively impermeable and hence extensive down flow systems through the sedimentary strata are possible only in the presence of generalized lateral movement of groundwater in the basal parts of the sedimentary basins. The direction of this lateral flow, inferred from the basement topography and geological characteristics of the region, is from west to east, following roughly the course of surface drainage system of the Amazon River, with eventual discharge into the Atlantic Ocean. The estimated flow rate at the continental margin is 3287 m3/s, with velocities of the order of 218 m/year. It is possible that dynamic changes in the fluvial systems in the western parts of South American continent have been responsible for triggering alterations in the groundwater recharge systems and deep seated lateral flows in the Amazon region.

  20. Chemical and carbon isotope composition of Varzeas sediments and its interactions with some Amazon basin rivers

    International Nuclear Information System (INIS)

    Varzea sediment samples were collected on the banks of Amazon rivers and in the most important tributaires. The samples were taken in three different river stages. The major cations, pH, total nitrogen, total phosphorus, carbon and δ13C values were determined. The concentration of major basic cations - Ca,Mg,K e Na were greater in the main channel sediments than in the tributaires. Probably the differences in the substrats geology and erosion regimes of the basins account for this patterns, generally. The major basic cation, total phosphorus and carbon concentration were lower in the low Amazon Varzeas. Between the three differents sampling periods, pratically the elements concentration in Varzea sediment was constant. Finally, the datas showed that the most parts of Varzea carbon sediment had it's origin in the fine particulated organic matter transported by the Amazon river. (C.D.G.)

  1. Clay mineral composition of river sediments in the Amazon Basin

    OpenAIRE

    Guyot, Jean-Loup; Jouanneau, J.M.; Soares, L; Boaventura, G.R.; Maillet, N; Lagane, Christelle

    2007-01-01

    Clay minerals are important in evaluating the maturity of suspended sediments, weathering intensity and source area. However, there are processes that can change the mineral assemblage such as river transportation, deposition, remobilization and tributary inputs. In terms of water discharge and sediment yield, the Amazon is one of the largest rivers in the world. Most of the suspended sediments come from the Andes, crossing the lowlands before reaching the ocean. This study measures the spati...

  2. Ballast water: a threat to the Amazon Basin.

    Science.gov (United States)

    Pereira, Newton Narciso; Botter, Rui Carlos; Folena, Rafael Dompieri; Pereira, José Pinheiro Fragoso Neto; da Cunha, Alan Cavalcanti

    2014-07-15

    Ballast water exchange (BWE) is the most efficient measure to control the invasion of exotic species from ships. This procedure is being used for merchant ships in national and international voyages. The ballast water (BW) salinity is the main parameter to evaluate the efficacy of the mid-ocean ballast water exchange. The vessels must report to the Port State Control (PSC), via ballast water report (BWR), where and how the mid-ocean BWE was performed. This measure allows the PSC to analyze this information before the ship arrives at the port, and to decide whether or not it should berth. Ship BW reporting forms were collected from the Captaincy of Santana and some ships were visited near the Port of Santana, located in Macapá (Amazon River), to evaluate the BW quality onboard. We evaluated data submitted in these BWR forms and concluded that the BWE efficacy might be compromised, because data contained in these BWR indicate that some ships did not change their BW. We found mistakes in filling the BWR forms and lack of information. Moreover, these ships had discharged BW with high level of salinity, Escherichia coli and total coliforms into the Amazon River. We concluded that the authorities of the Amazon Region need to develop more efficient proceedings to evaluate the ballast water reporting forms and BW quality, as there is potential risk of future invasion of exotic species in Brazilian ports.

  3. Annual Carbon Emissions from Deforestation in the Amazon Basin between 2000 and 2010.

    Science.gov (United States)

    Song, Xiao-Peng; Huang, Chengquan; Saatchi, Sassan S; Hansen, Matthew C; Townshend, John R

    2015-01-01

    Reducing emissions from deforestation and forest degradation (REDD+) is considered one of the most cost-effective strategies for mitigating climate change. However, historical deforestation and emission rates-critical inputs for setting reference emission levels for REDD+-are poorly understood. Here we use multi-source, time-series satellite data to quantify carbon emissions from deforestation in the Amazon basin on a year-to-year basis between 2000 and 2010. We first derive annual deforestation indicators by using the Moderate Resolution Imaging Spectroradiometer Vegetation Continuous Fields (MODIS VCF) product. MODIS indicators are calibrated by using a large sample of Landsat data to generate accurate deforestation rates, which are subsequently combined with a spatially explicit biomass dataset to calculate committed annual carbon emissions. Across the study area, the average deforestation and associated carbon emissions were estimated to be 1.59 ± 0.25 M ha•yr(-1) and 0.18 ± 0.07 Pg C•yr(-1) respectively, with substantially different trends and inter-annual variability in different regions. Deforestation in the Brazilian Amazon increased between 2001 and 2004 and declined substantially afterwards, whereas deforestation in the Bolivian Amazon, the Colombian Amazon, and the Peruvian Amazon increased over the study period. The average carbon density of lost forests after 2005 was 130 Mg C•ha(-1), ~11% lower than the average carbon density of remaining forests in year 2010 (144 Mg C•ha(-1)). Moreover, the average carbon density of cleared forests increased at a rate of 7 Mg C•ha(-1)•yr(-1) from 2005 to 2010, suggesting that deforestation has been progressively encroaching into high-biomass lands in the Amazon basin. Spatially explicit, annual deforestation and emission estimates like the ones derived in this study are useful for setting baselines for REDD+ and other emission mitigation programs, and for evaluating the performance of such efforts.

  4. Annual Carbon Emissions from Deforestation in the Amazon Basin between 2000 and 2010.

    Directory of Open Access Journals (Sweden)

    Xiao-Peng Song

    Full Text Available Reducing emissions from deforestation and forest degradation (REDD+ is considered one of the most cost-effective strategies for mitigating climate change. However, historical deforestation and emission rates-critical inputs for setting reference emission levels for REDD+-are poorly understood. Here we use multi-source, time-series satellite data to quantify carbon emissions from deforestation in the Amazon basin on a year-to-year basis between 2000 and 2010. We first derive annual deforestation indicators by using the Moderate Resolution Imaging Spectroradiometer Vegetation Continuous Fields (MODIS VCF product. MODIS indicators are calibrated by using a large sample of Landsat data to generate accurate deforestation rates, which are subsequently combined with a spatially explicit biomass dataset to calculate committed annual carbon emissions. Across the study area, the average deforestation and associated carbon emissions were estimated to be 1.59 ± 0.25 M ha•yr(-1 and 0.18 ± 0.07 Pg C•yr(-1 respectively, with substantially different trends and inter-annual variability in different regions. Deforestation in the Brazilian Amazon increased between 2001 and 2004 and declined substantially afterwards, whereas deforestation in the Bolivian Amazon, the Colombian Amazon, and the Peruvian Amazon increased over the study period. The average carbon density of lost forests after 2005 was 130 Mg C•ha(-1, ~11% lower than the average carbon density of remaining forests in year 2010 (144 Mg C•ha(-1. Moreover, the average carbon density of cleared forests increased at a rate of 7 Mg C•ha(-1•yr(-1 from 2005 to 2010, suggesting that deforestation has been progressively encroaching into high-biomass lands in the Amazon basin. Spatially explicit, annual deforestation and emission estimates like the ones derived in this study are useful for setting baselines for REDD+ and other emission mitigation programs, and for evaluating the performance of such

  5. Annual Carbon Emissions from Deforestation in the Amazon Basin between 2000 and 2010.

    Science.gov (United States)

    Song, Xiao-Peng; Huang, Chengquan; Saatchi, Sassan S; Hansen, Matthew C; Townshend, John R

    2015-01-01

    Reducing emissions from deforestation and forest degradation (REDD+) is considered one of the most cost-effective strategies for mitigating climate change. However, historical deforestation and emission rates-critical inputs for setting reference emission levels for REDD+-are poorly understood. Here we use multi-source, time-series satellite data to quantify carbon emissions from deforestation in the Amazon basin on a year-to-year basis between 2000 and 2010. We first derive annual deforestation indicators by using the Moderate Resolution Imaging Spectroradiometer Vegetation Continuous Fields (MODIS VCF) product. MODIS indicators are calibrated by using a large sample of Landsat data to generate accurate deforestation rates, which are subsequently combined with a spatially explicit biomass dataset to calculate committed annual carbon emissions. Across the study area, the average deforestation and associated carbon emissions were estimated to be 1.59 ± 0.25 M ha•yr(-1) and 0.18 ± 0.07 Pg C•yr(-1) respectively, with substantially different trends and inter-annual variability in different regions. Deforestation in the Brazilian Amazon increased between 2001 and 2004 and declined substantially afterwards, whereas deforestation in the Bolivian Amazon, the Colombian Amazon, and the Peruvian Amazon increased over the study period. The average carbon density of lost forests after 2005 was 130 Mg C•ha(-1), ~11% lower than the average carbon density of remaining forests in year 2010 (144 Mg C•ha(-1)). Moreover, the average carbon density of cleared forests increased at a rate of 7 Mg C•ha(-1)•yr(-1) from 2005 to 2010, suggesting that deforestation has been progressively encroaching into high-biomass lands in the Amazon basin. Spatially explicit, annual deforestation and emission estimates like the ones derived in this study are useful for setting baselines for REDD+ and other emission mitigation programs, and for evaluating the performance of such efforts. PMID

  6. Rivers, refuges and population divergence of fire-eye antbirds (Pyriglena) in the Amazon Basin.

    Science.gov (United States)

    Maldonado-Coelho, M; Blake, J G; Silveira, L F; Batalha-Filho, H; Ricklefs, R E

    2013-05-01

    The identification of ecological and evolutionary mechanisms that might account for the elevated biotic diversity in tropical forests is a central theme in evolutionary biology. This issue is especially relevant in the Neotropical region, where biological diversity is the highest in the world, but where few studies have been conducted to test factors causing population differentiation and speciation. We used mtDNA sequence data to examine the genetic structure within white-backed fire-eye (Pyriglena leuconota) populations along the Tocantins River valley in the south-eastern Amazon Basin, and we confront the predictions of the river and the Pleistocene refuge hypotheses with patterns of genetic variation observed in these populations. We also investigated whether these patterns reflect the recently detected shift in the course of the Tocantins River. We sampled a total of 32 individuals east of, and 52 individuals west of, the Tocantins River. Coalescent simulations and phylogeographical and population genetics analytical approaches revealed that mtDNA variation observed for fire-eye populations provides little support for the hypothesis that populations were isolated in glacial forest refuges. Instead, our data strongly support a key prediction of the river hypothesis. Our study shows that the Tocantins River has probably been the historical barrier promoting population divergence in fire-eye antbirds. Our results have important implications for a better understanding of the importance of large Amazonian rivers in vertebrate diversification in the Neotropics.

  7. Biogenic Aerosols Over the Amazon Basin: Optical Properties and Relationship With Elemental and Ionic Composition

    Science.gov (United States)

    Artaxo, P.; Martin, S. T.; Andreae, M. O.; Godoy, J. M.; Godoy, M. L.; Rizzo, L. V.; Paixao, M.

    2008-12-01

    We investigated the optical properties of natural biogenic aerosol particles over the central Amazon Basin near Manaus during the wet season in February and March 2008. The measurements were conducted as part of the AMAZE-08 (Amazonian Aerosol Characterization Experiment) sampling campaign. Light absorption was determined with the use of an Aethalometer and an MAAP (Multi Angle Absorption Photometer). Light scattering was measured with a 3 wavelength TSI nephelometer and an Ecotech nephelometer. The elemental composition was measured trough PIXE and IC. Single scattering albedo shows relatively low values varying from 0.86 to 0.95. Very low fine mode aerosol mass was measured, and coarse mode particles are responsible for a significant fraction of scattering and absorption. Sulfur was observed in very low concentrations, and most of the aerosol mass was organic. Long range transport of soil dust from Sahara were observed and reflected in the light scattering coefficient. Wavelength dependence of absorption indicates the strong influence of coarse mode aerosol. Aerosol optical thickness shows low values, but with significant single scattering albedo values, showing strong absorption properties of these biogenic aerosols. Size distribution measurements shows consistence with the scattering coefficients measured, if the coarse mode particles are taken into account.

  8. Seroprevalence of Toxoplasma gondii in free-living Amazon River dolphins (Inia geoffrensis) from central Amazon, Brazil.

    Science.gov (United States)

    Santos, P S; Albuquerque, G R; da Silva, V M F; Martin, A R; Marvulo, M F V; Souza, S L P; Ragozo, A M A; Nascimento, C C; Gennari, S M; Dubey, J P; Silva, J C R

    2011-12-29

    Toxoplasma gondii is an important pathogen in aquatic mammals and its presence in these animals may indicate the water contamination of aquatic environment by oocysts. Serum samples from 95 free-living Amazon River dolphins (Inia geoffrensis) from the Mamirauá Sustainable Development Reserve (RDSM), Tefé, Amazonas, Central Amazon, Brazil were tested for T. gondii antibodies using the modified agglutination test (MAT). Antibodies (MAT ≥ 25) to T. gondii were found in 82 (86.3%) dolphins with titers of 1:25 in 24, 1:50 in 56, and 1:500 in 2. Results suggest a high level contamination of the aquatic environment of the home range of these animals. PMID:21764516

  9. The effects of forest structure on occurrence and abundance of three owl species (Aves: Strigidae in the Central Amazon forest

    Directory of Open Access Journals (Sweden)

    Obed G. Barros

    2009-03-01

    Full Text Available We investigated how forest structure affects the occurrence and abundance of three owl species: the crested owl Lophostrix cristata Daudin, 1800, the Amazon pygmy owl Glaucidium hardyi Vielliard, 1990, and the tawny-bellied screech owl Megascops watsonii Cassin, 1849. We surveyed the owls mostly between 07:00 and 11:00 pm from July 2001 to April 2002, in eighteen 8 km transects along trails at the Ducke Reserve, Manaus, Central Amazon, Brazil. We staked out 50 x 50 m plots where the presence and absence of the owls were recorded. We compared some components of the forest structure between plots where owls were present and plots where they were absent. The spatial variation in these components were related to the occurrence and abundance of the owls using models of multiple logistic and multiple linear regressions analysis, respectively. Lophostrix cristata is rare in many other areas of the Amazon forest, but it was the most abundant in our study area. Lophostrix cristata and G. hardyi were more concentrated along the uplands (central plateau, which divide the reserve into two drainage water-basins. Megascops watsonii was distributed mainly in the southeastern part of the reserve. Glaucidium hardyi was more often found in areas with larger canopy openness. In areas with higher abundance of snags, there was significantly higher occurrence of L. cristata and M. watsonii. Megascops watsonii was also more abundant in areas with higher abundance of forest trees and in areas bearing shallower leaf litter on the forest floor. This study is the first to analyze at large spatial scale the effects of forest structure on neotropical forest top predator nocturnal birds. The results indicate that forest structure can affect the occurrence and abundance of owls in the Amazon forest.

  10. The cycle of biogenic sulfur compounds over the Amazon Basin. I - Dry season

    Science.gov (United States)

    Andreae, M. O.; Andreae, T. W.

    1988-01-01

    The concentrations of SO2, methylmercaptan, dimethylsulfide, H2S, aerosol sulfate, and methanesulfonate over the Amazon Basin during the July/August dry season were determined from samples collected by the NASA research aircraft. The results indicate that biogenic emissions represent an important, if not the dominant, source of sulfur to the atmosphere over Amazonia. Per unit area, the wet continental tropics appear to have about the same reduced sulfur emission flux as the oceanic area average (about 6 nmol/sq m per min), consistent with the fact that the aerosol sulfate concentration over the Amazon Basin is similar to the excess sulfate levels over the remote oceans. However, since the wet tropical continents represent only about 3 percent of the earth's surface, their global contribution is modest; it is also small relative to the anthropogenic emissions from fossil fuel burning.

  11. Palms and Palm Communities in the Upper Ucayali River Valley - a Little-Known Region in the Amazon Basin

    DEFF Research Database (Denmark)

    Balslev, Henrik; Eiserhardt, Wolf L.; Kristiansen, Thea;

    2010-01-01

    The Amazon region and its palms are inseparable. Palms make up such an important part of the rain forest ecosystem that it is impossible to imagine the Amazon basin without them. Palms are visible in the canopy and often fill up the forest understory. Palms – because of their edible fruits...... – are cornerstone species for the survival of many animals, and palms contribute substantially to forest inventories in which they are often among the ten most important families. Still, the palms and palm communities of some parts of the Amazon basin remain poorly studied and little known. We travelled to a little......-explored corner of the western Amazon basin, the upper Ucayali river valley. There, we encountered 56 different palms, 18 of which had not been registered for the region previously, and 21 of them were found 150–400 km beyond their previously known limits....

  12. Hemiodus iratapuru, a new species of Hemiodontidae from the Rio Jari, Amazon Basin, Brazil (Teleostei, Characiformes).

    Science.gov (United States)

    Langeani, F; Moreira, C R

    2013-04-01

    Hemiodus iratapuru, a new species of the Hemiodontidae from the Rio Iratapuru, a left bank tributary of the Rio Jari, Amazon Basin, Brazil, is described. The new species is diagnosed from other species of Hemiodus by modifications in the ectopterygoid, tooth form, scale counts, dorsal-fin form and colour pattern. The new species is proposed to be related to the Hemiodus quadrimaculatus species group.

  13. TOTAL MERCURY (HgT) BIOACCUMULATION AND FISH FOOD HABITS IN NEGRO RIVER BASIN, AMAZON, BRAZIL

    OpenAIRE

    Jean Louchard Ferreira Soares; Ynglea Georgina de Freitas Goch; José Reinaldo Pacheco Peleja; Bruce Rider Forsberg; Edivaldo Júnior de Souza Lemos; Otávio Peleja de Sousa

    2016-01-01

    In the Amazon, the fish is the main nutritional source for the riverine. Thus, fish have been commonly used in environmental monitoring work to be good biomonitors. This study analyzed the total mercury concentration (THg) in fish of different species and feeding habits in order to investigate the existence of bioaccumulation in species in the basin of the Negro river and verify that the THg levels found are in accordance with the stipulated limit for consumption human. Sampling points were d...

  14. Use of GNSS Data for Hydrological Surveys in the Amazon Basin

    Science.gov (United States)

    Medeiros Moreira, Daniel; Calmant, Stephane; Perosanz, Félix; Rotunno, Otto; Santos da Silva, Joecila; Santos, Andre

    2016-04-01

    GNSS data are constantly being used in hydrology. The key applications are the levelling of hydrological gauge stations, that of ADCP profiles for discharge and bathymetry of the cross-sections, and characterization of river's longitudinal slope of the free . These information are required to develop hydrological and hydrodynamic studies and to assess the quality of water level data obtained through space altimetry techniques. Establishing quality altimetry data from GNSS receivers to obtain gauge levelling and rivers profiles in the Amazon Basin is challenging. The GNSS reference network is sparse, the distance between survey points and reference stations is large, the major part of the basin can be only accessed by boat and rivers can have an extension of several thousands of kilometres. All these factors limit the efficiency of classical techniques of GNSS data processing like those based on double differences (DD). In addition, the Amazon Basin is strongly affected by loading effects, mainly caused by the hydrological cycle. In this basin, vertical displacements of these effects can reach more than 10 cm of amplitude. In the present work, we discuss the capability of calculating thousands of kilometres long altimetric profiles along the major rivers of the Amazon basin. GNSS data coming from receivers installed on-board boats are used together with GNSS stations fixed on gauges. First, differential techniques implemented in the GINS-PC software developed at the CNES-CLS IGS AC are used. These results are compared to those obtained with the Precise Point Position (PPP) technique. The impacts of fixing ambiguities to integer values in PPP technique are discussed as the use of Glonass data. We point on the specific corrections and cautions that are necessary during the data collection and the data processing. The accuracy of the profiles is assessed by comparing the results with fix points at gauge stations. The base application of the method is to enable fast

  15. Comparisons of observed and modeled elastic responses to hydrological loading in the Amazon basin

    Science.gov (United States)

    Moreira, D. M.; Calmant, S.; Perosanz, F.; Xavier, L.; Rotunno Filho, O. C.; Seyler, F.; Monteiro, A. C.

    2016-09-01

    In large hydrological basins, water mass loading can produce significant crustal deformation. We compare the monthly vertical component of 18 GPS sites located in the Amazon basin, with the deflection models derived from Gravity Recovery and Climate Experiment (GRACE) observations on the one hand and derived from HYDL, a global hydrological model, on the other hand. The GPS data set includes the largest deflections by hydrological loading ever recorded at two stations located in the center of the basin. The main result of the study is that the GRACE solution produced by GRGS (Groupe de Recherche en Géodesie Spatiale, Toulouse, France) produces the best agreement with the Global Navigation Satellite Systems series with a correlation coefficient up to 0.9 in the center of the basin, although 70% at best of the RMS variation in the GPS series is accounted for.

  16. Severe convection features in the Amazon Basin: a TRMM-based 15-year evaluation

    Science.gov (United States)

    Pereira Nunes, Ana; Silva Dias, Maria; Anselmo, Evandro; Rodriguez, Carlos

    2016-04-01

    Rainfall in the Amazon Basin is very heterogeneous, mainly because the area encompassed is quite large. Among the systems responsible for rainfall, some stand out as extreme storm events. This study presents a criterion for identifying potentially severe convection in the Amazon region from the Tropical Rainfall Measuring Mission (TRMM) database, specifically from Precipitation Features (PF) - 1998-2012 - generated and stored by the University of Utah. The seasonal and spatial distributions are similar to distributions of Mesoscale Convective Systems already catalogued in previous studies based on GOES satellite images. The seasons with the highest number of cases are austral spring, winter, and fall. With the Amazon region divided into six subregions and cases accumulated by quarter (JFM, AMJ, JAS, OND) the south of the Amazon subregion (SA) accounts for the largest number of cases with the OND quarter with higher occurrence and the lowest in AMJ. Different diurnal cycles of potentially severe convection are observed across the region with the more western areas, closer to the Andes, favoring nighttime cases, especially in the austral spring and summer. The diurnal cycle of the number of the most extreme cases is more pronounced than the diurnal cycle when a large collection of deep convection cases are included.

  17. Dynamics of Dissolved Organic Matter in Amazon Basin: Insights into Negro River Contribution

    Science.gov (United States)

    Moreira-Turcq, P.; Perez, M. P.; Benedetti, M.; Oliveira, M. A.; Lagane, C.; Seyler, P.; Oliveira, E.

    2006-12-01

    The study of global carbon cycle requires a precise knowledge of spatial and temporal distributions and exportation from continents to oceans. Organic carbon fluxes represent approximately half of the total carbon budget carried by rivers. Tropical rivers transport two third of the total organic carbon discharged into the world oceans but important gaps still exist in the knowledge of the tropical river carbon biochemistry. The Amazon River is responsible for 10% of the annual amount of organic carbon transported from rivers to oceans. The most important portion of total organic matter transported in the Amazon Basin is the dissolved fraction (between 80% and 95%). Amazonian annual flux of dissolved organic matter is directly related to hydrological variations. All rivers in the Amazon basin are characterized by monomodal hydrograms, with a low water period in october/november and a high water period in may/june. Temporal variations in Amazon dissolved organic carbon (3.0 to 9.1 mg l^{- 1}) are mainly controled by Negro River inputs. DOC and DON contributions from the Negro River can vary between 120 kgC s-1 and 520 kg C s-1, and between 5 kgN s--1 and 15 kgN s-1, during low and high water period, respectivelly. In the Negro River, during high water stages, while DOC concentrations are stable from the upstream stations to the downstream ones (about 11 mg l-1), discharge increases from 16000 to 46000 m3 s-1 and NOD can quintuple from upstream (0.071 mg l-1) to downstream (0.341 mg l-1). Then the nature of dissolved organic matter is variable (C/N ratio varied from 33 to 120 from upstream to downstream). During low water stages DOC concentrations are lower (mean DOC of 8.1 mg l-1) while DON is in the same range, discharge is about 10000 m3 s-1 at downstream stations of Negro River and the C/N ratio is lower and steadier along the River. Finaly, despite a low basin surface (12%) compared with the two other main Amazon tributaries, Solimões and Madeira Rivers, and a

  18. Reactive and dissolved meteoric 10Be/9Be ratios in the Amazon basin

    Science.gov (United States)

    Wittmann, Hella; Dannhaus, Nadine; von Blanckenburg, Friedhelm; Bouchez, Julien; Suessenberger, Annette; Guyot, Jean-Loup; Maurice, Laurence; Filizola, Naziano; Gaillardet, Jerome; Christl, Marcus

    2014-05-01

    Recently, the ratio of the meteoric cosmogenic nuclide 10Be to stable 9Be has been established as a weathering and erosion proxy where meteoric 10Be/9Be ratios in reactive phases of secondary weathering products leached from detrital Amazonian river sediment were measured[1]. For this dataset, we derived a new 10Be-based mass balance, which compares the fluxes exported during erosion and weathering, Fout, calculated by the sum of [10Be]reac multiplied by gauging-derived sediment discharge and [10Be]dissmultiplied by water discharge, to the meteoric depositional flux Fin. This assessment allows evaluating the weathering state of the Amazon basin. Further, in order to assess equilibration of reactive phases in the water column, we measured (10Be/9Be)reac ratios leached from suspended sediments for two depth profiles of the Amazon (55m depth) and Madeira (12m depth) Rivers, their corresponding surface dissolved 10Be/9Be ratios, as well as dissolved ratios of smaller Amazon tributaries (Beni, Madre de Dios) to compare with published reactive ratios[1]. In these rivers, modest pH and salinity fluctuations help to constrain a 'simple' system that might however still be affected by seasonally changing isotopic compositions between water and suspended sediment[2] and seasonal fluctuations of TSS and TDS[3]. The 10Be-based mass balance shows that in Andean source areas Fout/Fin ≡1, indicating a balance between ingoing and exported flux, whereas in the Shield headwaters, Fout/Fin=0.3, indicating a combination of decay of 10Be during storage and little export of 10Be associated with particulate and dissolved loads. In central Amazonia, the export of 10Be decreases slightly relative to its atmospheric flux as evidenced by Fout/Fin=0.8 for the Amazon and Madeira Rivers. This value is interpreted as being close to steady state, but its modification could be due to additions of Shield-derived sediment to sediment carried in the main river[4]. Regarding the depth profiles, our

  19. Potential negative effects of groundwater dynamics on dry season convection in the Amazon River basin

    Science.gov (United States)

    Lin, Yen-Heng; Lo, Min-Hui; Chou, Chia

    2016-02-01

    Adding a groundwater component to land surface models affects modeled precipitation. The additional water supply from the subsurface contributes to increased water vapor in the atmosphere, resulting in modifications of atmospheric convection. This study focuses on how groundwater dynamics affect atmospheric convection in the Amazon River basin (ARB) during July, typically the driest month. Coupled groundwater-land-atmosphere model simulations show that groundwater storage increases evapotranspiration rates (latent heat fluxes) and lowers surface temperatures, which increases the surface pressure gradient and thus, anomalous surface divergence. Therefore, the convection over the Southern Hemispheric ARB during the dry season becomes weaker when groundwater dynamics are included in the model. Additionally, the changes in atmospheric vertical water vapor advection are associated with decreases in precipitation that results from downwelling transport anomalies. The results of this study highlight the importance of subsurface hydrological processes in the Amazon climate system, with implications for precipitation changes during the dry season, observed in most current climate models.

  20. Biogenic cloud nuclei in the central Amazon during the transition from wet to dry season

    Science.gov (United States)

    Whitehead, James D.; Darbyshire, Eoghan; Brito, Joel; Barbosa, Henrique M. J.; Crawford, Ian; Stern, Rafael; Gallagher, Martin W.; Kaye, Paul H.; Allan, James D.; Coe, Hugh; Artaxo, Paulo; McFiggans, Gordon

    2016-08-01

    The Amazon basin is a vast continental area in which atmospheric composition is relatively unaffected by anthropogenic aerosol particles. Understanding the properties of the natural biogenic aerosol particles over the Amazon rainforest is key to understanding their influence on regional and global climate. While there have been a number of studies during the wet season, and of biomass burning particles in the dry season, there has been relatively little work on the transition period - the start of the dry season in the absence of biomass burning. As part of the Brazil-UK Network for Investigation of Amazonian Atmospheric Composition and Impacts on Climate (BUNIAACIC) project, aerosol measurements, focussing on unpolluted biogenic air masses, were conducted at a remote rainforest site in the central Amazon during the transition from wet to dry season in July 2013. This period marks the start of the dry season but before significant biomass burning occurs in the region. Median particle number concentrations were 266 cm-3, with size distributions dominated by an accumulation mode of 130-150 nm. During periods of low particle counts, a smaller Aitken mode could also be seen around 80 nm. While the concentrations were similar in magnitude to those seen during the wet season, the size distributions suggest an enhancement in the accumulation mode compared to the wet season, but not yet to the extent seen later in the dry season, when significant biomass burning takes place. Submicron nonrefractory aerosol composition, as measured by an aerosol chemical speciation monitor (ACSM), was dominated by organic material (around 81 %). Aerosol hygroscopicity was probed using measurements from a hygroscopicity tandem differential mobility analyser (HTDMA), and a quasi-monodisperse cloud condensation nuclei counter (CCNc). The hygroscopicity parameter, κ, was found to be low, ranging from 0.12 for Aitken-mode particles to 0.18 for accumulation-mode particles. This was consistent

  1. Manaus city Flow Warning system and extreme events monitoring in the Amazon Basin

    Science.gov (United States)

    Santos, A. L. M. R.; Oliveira, D.; Oliveira, M. A.; Moreira, D.; Maciel, J. S. C.

    2012-04-01

    The Amazon basin is the biggest watershed in the world, in the center of this basin, there is a city called Manaus, with population next to 2 million habitants. Manaus city is bounded by Negro River; one of the main rivers in Amazon, this river has its level checked by Fluvial Station in the Manaus harbor, which has a range of 100 years of hydrological data records. The hydrological cycle in the region next to Manaus has certain regularity, its common variety is considered of 7 months of rising river, in other words, the fluvial quotes rising and 5 months of falling (ebb). Although, the water level variation in Manaus Harbor, from its draft to flow can achieve the variation up to 16 meters of water level height, this difference can affect all the Amazon region, happening impacts such as the interference of regional agriculture and fluvial transportation, besides the economic activities in the harbor and local population welfare, arising from extreme events. Considering the relevance of prediction and accompanying of flows and drafts, the Geologic Survey of Brazil implemented, since 1989, a warning system to these extreme events. This paper focused to demonstrate the a warning system implemented from equations based on the Manaus Harbor quotes, since Negro River has a regular hydrological cycle, thus, it is possible to predict the highest quotes in the hydrological year, in advance till 75 days with accurate prediction, in a gap of 45 to 15 days before the flow. This paper presents, also, the biggest events occurred in a hundred years of records collected by Manaus Harbor, as example, the draft happened in December 2010 and the flow in June 2009, as well demonstrating the values and impacts in the Amazon region.

  2. Sediment budget in the Ucayali River basin, an Andean tributary of the Amazon River

    Science.gov (United States)

    Santini, W.; Martinez, J.-M.; Espinoza-Villar, R.; Cochonneau, G.; Vauchel, P.; Moquet, J.-S.; Baby, P.; Espinoza, J.-C.; Lavado, W.; Carranza, J.; Guyot, J.-L.

    2015-03-01

    Formation of mountain ranges results from complex coupling between lithospheric deformation, mechanisms linked to subduction and surface processes: weathering, erosion, and climate. Today, erosion of the eastern Andean cordillera and sub-Andean foothills supplies over 99% of the sediment load passing through the Amazon Basin. Denudation rates in the upper Ucayali basin are rapid, favoured by a marked seasonality in this region and extreme precipitation cells above sedimentary strata, uplifted during Neogene times by a still active sub-Andean tectonic thrust. Around 40% of those sediments are trapped in the Ucayali retro-foreland basin system. Recent advances in remote sensing for Amazonian large rivers now allow us to complete the ground hydrological data. In this work, we propose a first estimation of the erosion and sedimentation budget of the Ucayali River catchment, based on spatial and conventional HYBAM Observatory network.

  3. Water balance in the Amazon basin from a land surface model ensemble

    Energy Technology Data Exchange (ETDEWEB)

    Getirana, Augusto; Dutra, Emanuel; Guimberteau, Matthieu; Kam, Jonghun; Li, Hongyi; Decharme, Bertrand; Zhang, Zhengqiu J.; Ducharne, Agnes; Boone, Aaron; Balsamo, Gianpaolo; Rodell, Matthew; Mounirou Toure, Ally; Xue, Yongkang; Peters-Lidard, Christa D.; Kumar, Sujay V.; Arsenault, Kristi Rae; Drapeau, Guillaume; Leung, Lai-Yung R.; Ronchail, Josyane; Sheffield, Justin

    2014-12-06

    Despite recent advances in modeling and remote sensing of land surfaces, estimates of the global water budget are still fairly uncertain. The objective of this study is to evaluate the water budget of the Amazon basin based on several state-of-the-art land surface model (LSM) outputs. Water budget variables [total water storage (TWS), evapotranspiration (ET), surface runoff (R) and baseflow (B)] are evaluated at the basin scale using both remote sensing and in situ data. Fourteen LSMs were run using meteorological forcings at a 3-hourly time step and 1-degree spatial resolution. Three experiments are performed using precipitation which has been rescaled to match monthly global GPCP and GPCC datasets and the daily HYBAM dataset for the Amazon basin. R and B are used to force the Hydrological Modeling and Analysis Platform (HyMAP) river routing scheme and simulated discharges are compared against observations at 165 gauges. Simulated ET and TWS are compared against FLUXNET and MOD16A2 evapotranspiration, and GRACE TWS estimates in different catchments. At the basin scale, simulated ET ranges from 2.39mm.d-1 to 3.26mm.d-1 and a low spatial correlation between ET and P indicates that evapotranspiration does not depend on water availability over most of the basin. Results also show that other simulated water budget variables vary significantly as a function of both the LSM and precipitation used, but simulated TWS generally agree at the basin scale. The best water budget simulations resulted from experiments using the HYBAM dataset, mostly explained by a denser rainfall gauge network the daily rescaling.

  4. Late Quaternary Vegetation and Climate Change in the Amazon Basin Based on a 50,000 Year Pollen Record from the Amazon Fan, ODP Site 932

    Science.gov (United States)

    Haberle, Simon G.; Maslin, Mark A.

    1999-01-01

    Hemipelagic sediments from the Amazon deep-sea fan, ODP Site 932 (5° 12.7‧N, 47° 1.8‧W), and continental shelf provide a 50,000-yr-long pollen record of Amazon Basin vegetation. The age model for Hole 932A is constrained by eight magnetic remanence intensity features, one paleomagnetic excursion, and three AMS14C dates.Alchornea,Melastomataceae, Myrtaceae, and Moraceae/Urticaceae are dominant taxa in the pollen record between 40,200 and 19,800 cal yr B.P. Andean taxa, such asPodocarpusandHedyosmum,increase in abundance between 19,800 and 11,000 cal yr B.P. and prior to 40,200 cal yr B.P. The Holocene pollen assemblage, derived from Amazon River and continental shelf sediments, is dominated by secondary growth taxa, such asCecropia.Climatic factors influencing the development of glacial and interglacial tropical vegetation are considered by comparing marine with terrestrial records of vegetation change. This comparison shows that the Amazon Basin forests were not extensively replaced by savanna vegetation during the glacial period, contradicting the refugia hypothesis.

  5. Concept design of a clinic ship for the health care system in the Peruvian Amazon basin

    OpenAIRE

    Mendoza Vassallo, Pedro Nicolás; Biot, Marco; Bresciani, Ferruccio

    2013-01-01

    In the Peruvian Amazon basin rivers are the only link among the small communities, scattered on a wide territory. With that in mind and according to the needs of local communities, a health care network system based on mobile clinic units onboard small crafts has been conceived, within a cooperation programme between the Universidad Católica Santo Toribio de Mogrovejo (Perú) and the University of Trieste (Italy). This way, patients along the inland waterways can be reached. Ships to be operat...

  6. A new Hyphessobrycon (Ostariophysi: Characiformes: Characidae) from the middle Amazon basin, Brazil.

    Science.gov (United States)

    Lima, Flávio C T; Coutinho, Daniel P; Wosiacki, Wolmar B

    2014-10-08

    Hyphessobrycon montagi, new species, is described from tributaries of the Rio Arapiuns, a left margin affluent of the lower Rio Tapajós, Amazon basin, Pará, Brazil. The new species can be diagnosed from all its congeners by the possession of a combination of two well-defined humeral blotches, connected by a narrow stripe, and a caudal peduncle blotch. A putatively monophyletic Hyphessobrycon heterorhabdus species-group, restricted to H. heterorhabdus, H. amapaensis, and H. eschwartzae, is herein proposed based on shared derived features of color pattern. Alternative proposals of a "Hyphessobrycon heterorhabdus group" presented in the recent literature are evaluated and criticized.

  7. Globalization and the Spatial Economy: Implications for the Amazon Basin in the 21st Century

    Science.gov (United States)

    Arima, E.; Walker, R.; Richards, P.

    2011-12-01

    Global demand for food and energy will increase in the next decades as world population grows, incomes in developing countries rise, and new energy sources from biofuels are sought. Despite gains in productivity, much of the future demand for those agricultural products will be met by bringing new lands into production. Tropical forests, and in particular the Brazilian Amazon, the focus of our article, are already facing pressures from expanding production of soy, beef, cotton, and biofuels as deforestation advances the agricultural frontier. This article begins by reviewing the recent literature and provides evidences of indirect land cover change in the Amazon driven by the tandem soy - cattle, whereby mechanized agriculture encroaches on existing pastures, displacing them to the Amazonian frontier. We then consider conditions in the spatial economy that potentially inhibit ongoing forest loss. In particular, we address the prospect of forest transition in the Amazon basin. This necessitates a review of the so-called Borlaug hypothesis, and the circumstances under which land sparing occurs. Land sparing, a sufficient if not necessary condition for forest transition, represents a potential solution to environmental problems associated with land change, one that promotes sustainability by furthering rural development with improved technologies. The paper concludes by contrasting the current Brazilian agricultural and environmental policies with the conditions set in the previous section.

  8. Theorizing Land Cover and Land Use Change: The Peasant Economy of Colonization in the Amazon Basin

    Science.gov (United States)

    Caldas, Marcellus; Walker, Robert; Arima, Eugenio; Perz, Stephen; Aldrich, Stephen; Simmons, Cynthia

    2007-01-01

    This paper addresses deforestation processes in the Amazon basin. It deploys a methodology combining remote sensing and survey-based fieldwork to examine, with regression analysis, the impact household structure and economic circumstances on deforestation decisions made by colonist farmers in the forest frontiers of Brazil. Unlike most previous regression-based studies, the methodology implemented analyzes behavior at the level of the individual property. The regressions correct for endogenous relationships between key variables, and spatial autocorrelation, as necessary. Variables used in the analysis are specified, in part, by a theoretical development integrating the Chayanovian concept of the peasant household with spatial considerations stemming from von Thuenen. The results from the empirical model indicate that demographic characteristics of households, as well as market factors, affect deforestation in the Amazon. Thus, statistical results from studies that do not include household-scale information may be subject to error. From a policy perspective, the results suggest that environmental policies in the Amazon based on market incentives to small farmers may not be as effective as hoped, given the importance of household factors in catalyzing the demand for land. The paper concludes by noting that household decisions regarding land use and deforestation are not independent of broader social circumstances, and that a full understanding of Amazonian deforestation will require insight into why poor families find it necessary to settle the frontier in the first place.

  9. Contribution of regional sources to atmospheric methane over the Amazon Basin in 2010 and 2011

    Science.gov (United States)

    Wilson, Chris; Gloor, Manuel; Gatti, Luciana V.; Miller, John B.; Monks, Sarah A.; McNorton, Joey; Bloom, A. Anthony; Basso, Luana S.; Chipperfield, Martyn P.

    2016-03-01

    We present an assessment of methane (CH4) atmospheric concentrations over the Amazon Basin for 2010 and 2011 using a 3-D atmospheric chemical transport model, two wetland emission models, and new observations made during biweekly flights made over four locations within the basin. We attempt to constrain basin-wide CH4 emissions using the observations, and since 2010 was an unusually dry year, we assess the effect of this drought on Amazonian methane emissions. We find that South American emissions contribute up to 150 ppb to concentrations at the sites, mainly originating from within the basin. Our atmospheric model simulations agree reasonably well with measurements at three of the locations (0.28 ≤ r2 ≤ 0.63, mean bias ≤ 9.5 ppb). Attempts to improve the simulated background CH4 concentration through analysis of simulated and observed sulphur hexafluoride concentrations do not improve the model performance, however. Through minimisation of seasonal biases between the simulated and observed atmospheric concentrations, we scale our prior emission inventories to derive total basin-wide methane emissions of 36.5-41.1 Tg(CH4)/yr in 2010 and 31.6-38.8 Tg(CH4)/yr in 2011. These totals suggest that the Amazon contributes significantly (up to 7%) to global CH4 emissions. Our analysis indicates that factors other than precipitation, such as temperature variations or tree mortality, may have affected microbial emission rates. However, given the uncertainty of our emission estimates, we cannot say definitively whether the noncombustion emissions from the region were different in 2010 and 2011, despite contrasting meteorological conditions between the two years.

  10. Neogene vegetation development in the Amazon Basin: evidence from marine well-2, Foz do Amazonas (Brazil)

    Science.gov (United States)

    Bogota-Angel, Raul; Chemale Junior, Farid; Davila, Roberto; Soares, Emilson; Pinto, Ricardo; Do Carmo, Dermeval; Hoorn, Carina

    2014-05-01

    Origen and development of the highly diverse Amazon tropical forest has mostly been inferred from continental sites. However, sediment records in the marine Foz do Amazonas Basin can provide important information to better understand the influence of the Andes uplift and climate change on its plant biomes evolution since the Neogene. Sediment analyses of samples from BP-Petrobras well 1 and 2, drilled in the Amazon Fan, allowed to infer the onset of the transcontinental Amazon river and the fan phase during the middle to late Miocene (c. 10.5 Ma). As part of the CLIMAMAZON research programme we performed pollen analysis on the 10.5 to 0.4 Ma time interval. 76 ditch cutting samples of the upper 4165 m sediments of well 2 permitted us to infer changes in floral composition in the Amazon Basin. The palynological spectra across this interval (nannofossil based age model) include pollen, fern spores, dinocysts and foram lignings. When possible pollen and fern spores were grouped in four vegetation types: estuarine, tropical, mountain forest and high mountain open treeless vegetation. Pollen is generally corroded and reflects the effects of sediment transportation while reworked material is also common. Good pollen producers such as Poaceae, Asteraceae and Cyperaceae are common and reflect indistinctive vegetation types particularly those associated to riverine systems. Rhizophora/Zonocostites spp. indicate "close-distance" mangrove development. Tropical forest biomes are represented by pollen that resemble Moraceae-Urticaceae, Melastomataceae-Combretaceae, Sapotaceae, Alchornea, Euphorbiaceae, Rubiaceae, Bignoniaceae, Mauritia and Arecaceae. Myrica, and particularly sporadic occurrences of fossil fern spores like Lophosoria, and Cyathea suggest the development of a moist Andean forest in areas above 1000 m. First indicators of high altitudes appear in the last part of late Miocene with taxa associated to current Valeriana and particularly Polylepis, a neotropical taxon

  11. Amazon dams and waterways: Brazil's Tapajós Basin plans.

    Science.gov (United States)

    Fearnside, Philip M

    2015-09-01

    Brazil plans to build 43 "large" dams (>30 MW) in the Tapajós Basin, ten of which are priorities for completion by 2022. Impacts include flooding indigenous lands and conservation units. The Tapajós River and two tributaries (the Juruena and Teles Pires Rivers) are also the focus of plans for waterways to transport soybeans from Mato Grosso to ports on the Amazon River. Dams would allow barges to pass rapids and waterfalls. The waterway plans require dams in a continuous chain, including the Chacorão Dam that would flood 18,700 ha of the Munduruku Indigenous Land. Protections in Brazil's constitution and legislation and in international conventions are easily neutralized through application of "security suspensions," as has already occurred during licensing of several dams currently under construction in the Tapajós Basin. Few are aware of "security suspensions," resulting in little impetus to change these laws.

  12. A new species of the armored catfish Parotocinclus (Loricariidae: Hypoptopomatinae, from the Amazon basin in Colombia

    Directory of Open Access Journals (Sweden)

    Pablo Lehmann A.

    2015-03-01

    Full Text Available A new species of hypoptopomatine cascudinho is described from a creek tributary to the Amazon River in Leticia, Amazonas Departament, Colombia. The new species of Parotocinclus is distinguished from congeners from northeastern to southeastern Brazilian rivers in having the cheek canal plate elongated posteriorly on the ventral surface of head and contacting the cleithrum. It is diagnosed from P. collinsae (Essequibo River basin, Guiana and P. halbothi (rio Trombetas basin, Brazil and Marowijne River, Suriname, by having a triangular patch of dark pigmentation on the anterior portion of the dorsal-fin membrane, by the absence of unicuspid accessory teeth on both the premaxilla and dentary, and by having a Y-shaped light mark on the snout. The new species of Parotocinclus is distinguished from all remaining congeners by having a pigmentation pattern consisting of conspicuous dark dots smaller than a pupil diameter, broadly distributed dorsally and ventrally.

  13. Validation of SARAL/AltiKa data in the Amazon basin

    Science.gov (United States)

    Santos da Silva, Joecila; Calmant, Stephane; Medeiros Moreira, Daniel; Oliveira, Robson; Conchy, Taina; Gennero, Marie-Claude; Seyler, Frederique

    2015-04-01

    SARAL/AltiKa is a link between past missions (since it flies on the ERS-ENVISAT orbit with Ku band nadir altimeters in LRM) and future missions such as SWOT's Ka band interferometry swaths. In the present study, we compare the capability of its altimeter AltiKa to that of previous missions working in the Ku band such as ENVISAT and Jason-2 in retrieving water levels over the Amazon basin. Same as for the aforementioned preceding missions, the best results were obtained with the ICE-1 retracking algorithm. We qualitatively analyze the impact of rainfalls in the loss of measurements. Since making long -multi mission- time series is of major importance either for hydro-climatic studies or for basin management, we also present an estimate of the altimeter bias in order that the SARAL series of water level can be appended to those of these previous missions.

  14. Assessment of climate change impacts on streamflow dynamics in the headwaters of the Amazon River basin

    Science.gov (United States)

    Yoon, Y.; Beighley, E.

    2015-12-01

    The Amazon River basin is the largest watershed in the world containing thousands of tributaries. Although the mainstream and its larger tributaries have been the focus on much research, there has been few studies focused on the hydrodynamics of smaller rivers in the foothills of the Andes Mountains. These smaller rivers are of particular importance for the fishery industry because fish migrate up these headwater rivers to spawn. During the rainy season, fish wait for storm event to increase water depths to a sufficient level for their passage. Understanding how streamflow dynamics will change in response to future conditions is vital for the sustainable management of the fishery industry. In this paper, we focus on improving the accuracy of river discharge estimates on relatively small-scale sub-catchments (100 ~ 40,000 km2) in the headwaters of the Amazon River basin. The Hillslope River Routing (HRR) hydrologic model and remotely sensed datasets are used. We provide annual runoff, seasonal patterns, and daily discharge characteristics for 81 known migration reaches. The model is calibrated for the period 2000-2014 and climate forecasts for the period 2070-2100 are used to assess future changes in streamflow dynamics. The forecasts for the 2070 to 2100 period were obtained by selecting 5 climate models from IPCC's Fifth Assessment Report (AR5) Coupled Model Intercomparison Project Phase 5 (CMIP5) based on their ability to represent the main aspects of recent (1970 to 2000) Amazon climate. The river network for the HRR model is developing using surface topography based on the SRTM digital elevation model. Key model forcings include precipitation (TRMM 3B42) and evapotranspiration (MODIS ET, MOD16). Model parameters for soil depth, hydraulic conductivity, runoff coefficients and lateral routing were initially approximated based on literature values and adjusted during calibration. Measurements from stream gauges located near the reaches of interest were used for

  15. A Behavioral Model of Landscape Change in the Amazon Basin: The Colonist Case

    Science.gov (United States)

    Walker, R. A.; Drzyzga, S. A.; Li, Y. L.; Wi, J. G.; Caldas, M.; Arima, E.; Vergara, D.

    2004-01-01

    This paper presents the prototype of a predictive model capable of describing both magnitudes of deforestation and its spatial articulation into patterns of forest fragmentation. In a departure from other landscape models, it establishes an explicit behavioral foundation for algorithm development, predicated on notions of the peasant economy and on household production theory. It takes a 'bottom-up' approach, generating the process of land-cover change occurring at lot level together with the geography of a transportation system to describe regional landscape change. In other words, it translates the decentralized decisions of individual households into a collective, spatial impact. In so doing, the model unites the richness of survey research on farm households with the analytical rigor of spatial analysis enabled by geographic information systems (GIs). The paper describes earlier efforts at spatial modeling, provides a critique of the so-called spatially explicit model, and elaborates a behavioral foundation by considering farm practices of colonists in the Amazon basin. It then uses, insight from the behavioral statement to motivate a GIs-based model architecture. The model is implemented for a long-standing colonization frontier in the eastern sector of the basin, along the Trans-Amazon Highway in the State of Para, Brazil. Results are subjected to both sensitivity analysis and error assessment, and suggestions are made about how the model could be improved.

  16. Beyond the model democracy: observational constraints indicate risk of drying in the Amazon basin

    Science.gov (United States)

    Shiogama, Hideo; Emori, Seita; Hanasaki, Naota; Abe, Manabu; Masutomi, Yuji; Takahashi, Kiyoshi; Nozawa, Toru

    2013-04-01

    Climate warming due to human activities will be accompanied by hydrological cycle changes. Economies, societies and ecosystems in South America (SA) are vulnerable to such water resource changes. Hence, water resource impact assessments for SA, and corresponding adaptation and mitigation policies, have attracted increased attention. However, substantial uncertainties remain in the current water resource assessments that are based on multiple coupled Atmosphere Ocean General Circulation models. This uncertainty varies from significant wetting to catastrophic drying. By applying a statistical method, we characterised the uncertainty and identified global-scale metrics for measuring the reliability of water resource assessments in SA. Here we show that, whereas the ensemble mean assessment suggested wetting across most of SA, the observational constraints indicate a higher probability of drying in the Amazon basin. Naive over-reliance on the consensus of models can lead to inappropriate decision making. Reference: Shiogama, H. et al. Observational constraints indicate risk of drying in the Amazon basin. Nature Communications 2:253 doi: 10.1038/ncomms1252 (2011).

  17. Isolation of viruses from mosquitoes (Diptera: Culicidae) collected in the Amazon Basin region of Peru.

    Science.gov (United States)

    Turell, M J; O'Guinn, M L; Jones, J W; Sardelis, M R; Dohm, D J; Watts, D M; Fernandez, R; Travassos da Rosa, A; Guzman, H; Tesh, R; Rossi, C A; Ludwig, V; Mangiafico, J A; Kondig, J; Wasieloski, L P; Pecor, J; Zyzak, M; Schoeler, G; Mores, C N; Calampa, C; Lee, J S; Klein, T A

    2005-09-01

    As part of a comprehensive study on the ecology of arthropod-borne viruses in the Amazon Basin region of Peru, we assayed 539,694 mosquitoes captured in Loreto Department, Peru, for arboviruses. Mosquitoes were captured either by dry ice-baited miniature light traps or with aspirators while mosquitoes were landing on human collectors, identified to species, and later tested on Vero cells for virus. In total, 164 virus isolations were made and included members of the Alphavirus (eastern equine encephalomyelitis, Trocara, Una, Venezuelan equine encephalomyelitis, and western equine encephalomyelitis viruses), Flavivirus (Ilheus and St. Louis encephalitis), and Orthobunyavirus (Caraparu, Itaqui, Mirim, Murutucu, and Wyeomyia viruses) genera. In addition, several viruses distinct from the above-mentioned genera were identified to the serogroup level. Eastern equine encephalomyelitis virus was associated primarily with Culex pedroi Sirivanakarn & Belkin, whereas Venezuelan equine encephalomyelitis virus was associated primarily with Culex gnomatos Sallum, Huchings & Ferreira. Most isolations of Ilheus virus were made from Psorophora ferox (Von Humboldt). Although species of the Culex subgenus Melanoconion accounted for only 45% of the mosquitoes collected, 85% of the virus isolations were made from this subgenus. Knowledge of the viruses that are being transmitted in the Amazon Basin region of Peru will enable the development of more effective diagnostic assays, more efficient and rapid diagnoses of clinical illnesses caused by these pathogens, risk analysis for military/civilian operations, and development of potential disease control measures.

  18. Dependence of hydropower energy generation on forests in the Amazon Basin at local and regional scales.

    Science.gov (United States)

    Stickler, Claudia M; Coe, Michael T; Costa, Marcos H; Nepstad, Daniel C; McGrath, David G; Dias, Livia C P; Rodrigues, Hermann O; Soares-Filho, Britaldo S

    2013-06-01

    Tropical rainforest regions have large hydropower generation potential that figures prominently in many nations' energy growth strategies. Feasibility studies of hydropower plants typically ignore the effect of future deforestation or assume that deforestation will have a positive effect on river discharge and energy generation resulting from declines in evapotranspiration (ET) associated with forest conversion. Forest loss can also reduce river discharge, however, by inhibiting rainfall. We used land use, hydrological, and climate models to examine the local "direct" effects (through changes in ET within the watershed) and the potential regional "indirect" effects (through changes in rainfall) of deforestation on river discharge and energy generation potential for the Belo Monte energy complex, one of the world's largest hydropower plants that is currently under construction on the Xingu River in the eastern Amazon. In the absence of indirect effects of deforestation, simulated deforestation of 20% and 40% within the Xingu River basin increased discharge by 4-8% and 10-12%, with similar increases in energy generation. When indirect effects were considered, deforestation of the Amazon region inhibited rainfall within the Xingu Basin, counterbalancing declines in ET and decreasing discharge by 6-36%. Under business-as-usual projections of forest loss for 2050 (40%), simulated power generation declined to only 25% of maximum plant output and 60% of the industry's own projections. Like other energy sources, hydropower plants present large social and environmental costs. Their reliability as energy sources, however, must take into account their dependence on forests.

  19. TOTAL MERCURY (HgT BIOACCUMULATION AND FISH FOOD HABITS IN NEGRO RIVER BASIN, AMAZON, BRAZIL

    Directory of Open Access Journals (Sweden)

    Jean Louchard Ferreira Soares

    2016-03-01

    Full Text Available In the Amazon, the fish is the main nutritional source for the riverine. Thus, fish have been commonly used in environmental monitoring work to be good biomonitors. This study analyzed the total mercury concentration (THg in fish of different species and feeding habits in order to investigate the existence of bioaccumulation in species in the basin of the Negro river and verify that the THg levels found are in accordance with the stipulated limit for consumption human. Sampling points were distributed in the basin of the Negro river during the period of high water. After the fisheries specimens were identified, measured and weighed. Then muscle samples were taken and subjected to acid digestion and analyzed by Cold Vapor Atomic Fluorescence Spectrophotometer - CVAFS. To research data was used analysis of variance and linear regression. A total of 264 specimens distributed into 10 species were analyzed, and the THg of the concentrations ranged from 0.030 for 1,670 mg.kg-1. The species Hoplias malabaricus, Serrasalmus rhombeus, Hemiodus immaculatus and Cichla temensis showed bioaccumulation. High concentrations of THg were found in carnivorous, piscivorous, planctívos and omnivores fish. No specimen showed mean concentrations of THg in violation to ANVISA, but this occurred in relation to FAO and WHO. keywords: Brazilian Amazon; biomonitoring; high waters; Hg.

  20. Improving Terrestrial Carbon and Water Simulations with Dynamic Root Distribution over the Amazon Basin

    Science.gov (United States)

    Wang, Y.; Xie, Z.; Jia, B.

    2015-12-01

    Realistic representation of roots and their behavior are important in hydrological, ecological and climate modeling. However, land surface models currently prescribe rooting profiles as a function of only the plant functional types, with no consideration of the dynamic rooting strategies in response to the changing environments. In this study, a new dynamic rooting scheme which taking the controlling effects of soil water and nitrogen on rooting strategies into account was incorporated into the version 4.5 of the Community Land Model with carbon-nitrogen interactions (CLM4.5-CN). Two pairs of experiments were conducted to study the effects of dynamic root distribution on eco-hydrological modeling for the Tapajos National Forest km83 (BRSa3) site and the Amazon Basin. For site-level comparisons, the dynamic rooting scheme can improve the carbon and water cycle modeling by reducing the root-mean-square error (RMSE) in gross primary production (GPP) by 0.4 g C m-2 day-1, net ecosystem exchange (NEE) by 1.96 g C m-2 day-1, latent heat (LE) by 5.0 W m-2, soil moisture (SM) by 0.03 m3 m-3. In the Amazon basin, the vegetation responses (including GPP and LE) to seasonal drought and server 2005 drought are also better captured with dynamic root distribution incorporated.

  1. The atmospheric sulfur cycle over the Amazon Basin. II - Wet season

    Science.gov (United States)

    Andreae, M. O.; Bingemer, H.; Berresheim, H.; Jacob, D. J.; Lewis, B. L.

    1990-01-01

    The fluxes and concentrations of atmospheric sulfur species were determined at ground level and from aircraft over the Amazon Basin during the 1987 wet season, providing a comprehensive description of the sulfur cycle over a remote tropical region. The vertical profile of dimethylsulfide (DMS) during the wet season was found to be very similar to that measured during the dry season, suggesting little seasonal variation in DMS fluxes. The concentrations of H2S were almost an order of magnitude higher than those of DMS, which makes H2S the most important biogenic source species in the atmosheric sulfur cycle over the Amazon Basin. Using the gradient-flux approach, the flux of DMS at the top of the tree canopy was estimated. The canopy was a source of DMS during the day, and a weak sink during the night. Measurements of sulfur gas emissions from soils, using the chamber method, showed very small fluxes, consistent with the hypothesis that the forest canopy is the major source of sulfur gases. The observed soil and canopy emission fluxes are similar to those measured in temperate regions. The concentrations of SO2 and sulfate aerosol in the wet season atmosphere were similar to dry season values.

  2. Complete Genome Sequence of Mayaro Virus Imported from the Amazon Basin to São Paulo State, Brazil.

    Science.gov (United States)

    Mota, Mânlio Tasso Oliveira; Vedovello, Danila; Estofolete, Cassia; Malossi, Camila Dantas; Araújo, João Pessoa; Nogueira, Maurício Lacerda

    2015-11-25

    Mayaro (MAYV) is a neglected arbovirus from the tropical Americas. Here, we report the complete genome of an MAYV isolate from a patient returning from the Amazon basin and complaining of arthralgia, high fever, and headache, who was attended at an emergency service of São José do Rio Preto, São Paulo state, Brazil.

  3. Large-scale circulation patterns and related rainfall in the Amazon Basin: a neuronal networks approach

    Energy Technology Data Exchange (ETDEWEB)

    Espinoza, Jhan Carlo [LOCEAN - IPSL (IRD, CNRS, MNHN, UPMC), Paris Cedex 05 (France); Universidad Agraria La Molina UNALM, Lima (Peru); Lengaigne, Matthieu; Janicot, Serge [LOCEAN - IPSL (IRD, CNRS, MNHN, UPMC), Paris Cedex 05 (France); Ronchail, Josyane [LOCEAN - IPSL (IRD, CNRS, MNHN, UPMC), Paris Cedex 05 (France); Universite Paris 7, Paris (France)

    2012-01-15

    This study describes the main circulation patterns (CP) in the Amazonian Basin over the 1975-2002 period and their relationship with rainfall variability. CPs in the Amazonian Basin have been computed for each season from the ERA-40 daily 850 hPa winds using an approach combining artificial neural network (Self Organizing Maps) and Hierarchical Ascendant Classification. A 6 to 8 cluster solutions (depending on the season considered) is shown to yield an integrated view of the complex regional circulation variability. For austral fall, winter and spring the temporal evolution between the different CPs shows a clear tendency to describe a cycle, with southern wind anomalies and their convergence with the trade winds progressing northward from the La Plata Basin to the Amazon Basin. This sequence is strongly related to eastward moving extra tropical perturbations and their incursion toward low latitude that modulate the geopotential and winds over South America and its adjoining oceans. During Austral summer, CPs are less spatially and temporally organized compared to other seasons, principally due to weaker extra tropical perturbations and more frequent shallow low situations. Each of these CPs is shown to be associated with coherent northward moving regional rainfall patterns (both in in situ data and ERA-40 reanalysis) and convective activity. However, our results reveals that precipitation variability is better reproduced by ERA-40 in the southern part of the Amazonian Basin than in the northern part, where rainfall variability is likely to be more constrained by local and subdaily processes (e.g. squall lines) that could be misrepresented in the reanalysis dataset. This analysis clearly illustrates the existing connections between the southern and northern part of the Amazonian Basin in terms of regional circulation/rainfall patterns. The identification of these CPs provide useful information to understand local rainfall variability and could hence be used to

  4. Late Quaternary Paleohydrology of the Madre de Dios River, southwestern Amazon Basin, Peru

    Science.gov (United States)

    Rigsby, Catherine A.; Hemric, Erin M.; Baker, Paul A.

    2009-12-01

    Late Quaternary climatic and hydrologic variability triggered changes in fluvial deposition and erosion along the course of the Madre de Dios River, Peru, the largest tributary basin of the Madeira basin, itself the largest tributary basin of the Amazon. Three laterally extensive, Quaternary-age, terrace tracts are present within the Madre de Dios basin. Analysis of sedimentary facies, present in the modern cut banks and terraced sequences, along with radiocarbon dates on fossil wood and leaf material preserved in the terraced strata, allow reconstruction of the Late Quaternary depositional history of the sedimentary sequences, including determination of the approximate timing of aggradation and downcutting episodes and its relationship to the timing of past climate change in this portion of the Amazon basin and beyond. The Quaternary sediments underlying the terraces most often recorded deposition in a coarse-grained meandering fluvial system. The T3 terrace, the highest terrace, is underlain by the Miocene (?) Ipururi Formation, which is unconformably overlain by the late Miocene-Pleistocene (?) (> 48,000 cal yrs BP) Madre de Dios Formation, a multistory coarse-sandy to gravelly channel and point bar complex. The latter was downcut before 29,850 ± 100 cal yrs BP. This downcut landscape was infilled by meandering fluvial strata characterized by gravelly channel deposits in a sequence dominated by floodplain and lateral accretion deposits. These strata were in turn downcut to form the T2 terrace before 11,970 ± 100 cal yrs BP. A third episode of aggradation resulted in the deposition of a sand-dominated meandering channel complex that infilled the T2 valley and was subsequently downcut after 3780 ± 50 cal yrs BP. This most recent terrace is infilled by the modern fluvial sediment, which has been actively aggrading since at least 870 ± 50 cal yrs BP. Importantly, the Madre de Dios fluvial system actively aggraded between 30,000 and 25,000 cal yrs BP, (and likely

  5. Stage-discharge rating curves based on satellite altimetry and modeled discharge in the Amazon basin

    Science.gov (United States)

    Paris, Adrien; Dias de Paiva, Rodrigo; Santos da Silva, Joecila; Medeiros Moreira, Daniel; Calmant, Stephane; Garambois, Pierre-André; Collischonn, Walter; Bonnet, Marie-Paule; Seyler, Frederique

    2016-05-01

    In this study, rating curves (RCs) were determined by applying satellite altimetry to a poorly gauged basin. This study demonstrates the synergistic application of remote sensing and watershed modeling to capture the dynamics and quantity of flow in the Amazon River Basin, respectively. Three major advancements for estimating basin-scale patterns in river discharge are described. The first advancement is the preservation of the hydrological meanings of the parameters expressed by Manning's equation to obtain a data set containing the elevations of the river beds throughout the basin. The second advancement is the provision of parameter uncertainties and, therefore, the uncertainties in the rated discharge. The third advancement concerns estimating the discharge while considering backwater effects. We analyzed the Amazon Basin using nearly one thousand series that were obtained from ENVISAT and Jason-2 altimetry for more than 100 tributaries. Discharge values and related uncertainties were obtained from the rain-discharge MGB-IPH model. We used a global optimization algorithm based on the Monte Carlo Markov Chain and Bayesian framework to determine the rating curves. The data were randomly allocated into 80% calibration and 20% validation subsets. A comparison with the validation samples produced a Nash-Sutcliffe efficiency (Ens) of 0.68. When the MGB discharge uncertainties were less than 5%, the Ens value increased to 0.81 (mean). A comparison with the in situ discharge resulted in an Ens value of 0.71 for the validation samples (and 0.77 for calibration). The Ens values at the mouths of the rivers that experienced backwater effects significantly improved when the mean monthly slope was included in the RC. Our RCs were not mission-dependent, and the Ens value was preserved when applying ENVISAT rating curves to Jason-2 altimetry at crossovers. The cease-to-flow parameter of our RCs provided a good proxy for determining river bed elevation. This proxy was validated

  6. Simulation of Water Sources and Precipitation Recycling for the MacKenzie, Mississippi and Amazon River Basins

    Science.gov (United States)

    Bosilovich, Michael G.; Chern, Jiun-Dar

    2005-01-01

    An atmospheric general circulation model simulation for 1948-1997 of the water budgets for the MacKenzie, Mississippi and Amazon River basins is presented. In addition to the water budget, we include passive tracers to identify the geographic sources of water for the basins, and the analysis focuses on the mechanisms contributing to precipitation recycling in each basin. While each basin s precipitation recycling has a strong dependency on evaporation during the mean annual cycle, the interannual variability of the recycling shows important relationships with the atmospheric circulation. The MacKenzie River basin has only a weak interannual dependency on evaporation, where the variations in zonal moisture transport from the Pacific Ocean can affect the basin water cycle. On the other hand, the Mississippi River basin has strong interannual dependencies on evaporation. While the precipitation recycling weakens with increased low level jet intensity, the evaporation variations exert stronger influence in providing water vapor for convective precipitation at the convective cloud base. High precipitation recycling is also found to be partly connected to warm SSTs in the tropical Pacific Ocean. The Amazon River basin evaporation exhibits small interannual variations, so that the interannual variations of precipitation recycling are related to atmospheric moisture transport from the tropical south Atlantic Ocean. Increasing SSTs over the 50-year period are causing increased easterly transport across the basin. As moisture transport increases, the Amazon precipitation recycling decreases (without real time varying vegetation changes). In addition, precipitation recycling from a bulk diagnostic method is compared to the passive tracer method used in the analysis. While the mean values are different, the interannual variations are comparable between each method. The methods also exhibit similar relationships to the terms of the basin scale water budgets.

  7. Succession-inducing disturbances and the old-growth forest mosaic of a Central Amazon landscape

    Science.gov (United States)

    Chambers, J. Q.; Negron Juarez, R. I.; Marra, D.; Roberts, D. A.; Di Vittorio, A. V.; Higuchi, N.; Trumbore, S.

    2011-12-01

    Old-growth forest ecosystems comprise a mosaic of patches in different successional stages, with the fraction of the landscape in any particular state relatively constant over large temporal and spatial scales. Tropical forest studies commonly assume that plots covering only a small fraction of the landscape representatively sample this mosaic, and that departures from steady-state represent trends. Here a critical test of this equilibrium assumption for a Central Amazon old-growth forest landscape is carried out by combining extensive forest field plot data, remote sensing analysis to generate disturbance probability distribution functions, and simulation modeling to place plot-level results into a landscape context. Results show that succession-inducing disturbances had a return frequency of ~100 years, and that these episodic events have been poorly sampled by existing forest sample plots. Overall, key ecosystem attributes of small patches are expected to constantly change in the Central Amazon, and long significant trends can result from purely stochastic processes. The role of episodic disturbances will be discussed in terms of Amazon forest carbon balance, and regional tree diversity patterns.

  8. Incidence of childhood leukemia and oil exploitation in the Amazon basin of Ecuador.

    Science.gov (United States)

    Hurtig, Anna-Karin; San Sebastián, Miguel

    2004-01-01

    To determine whether there was any difference in childhood leukemia incidence rates between populations living in the proximity to oil fields and those living in areas free from oil exploitation in the Amazon basin of Ecuador, 91 cancer cases among children (0-14 years) from the provinces of Sucumbios, Orellana, Napo, and Pastaza during the period 1985-2000 were studied. The relative risks for all leukemias indicated significantly elevated levels in the youngest age group (0-4 years), both genders combined (RR 3.48, 95% CI 1.25-9.67), and in all age groups (0-14 years) combined for females (RR 2.60, 95% CI 1.11-6.08) and both genders combined (RR 2.56, 95% CI 1.35-4.86). There was no significant difference between the two groups in all other cancer sites combined. Study results are compatible with a relationship between childhood leukemia incidence and living in the proximity of oil fields in the Ecuadorian Amazon.

  9. Evaluation of organic compounds and trace elements in Amazon Creek Basin, Oregon, September 1990

    Science.gov (United States)

    Rinella, F.A.

    1993-01-01

    Water and bottom sediment were collected from Amazon Creek, Oregon during a summer low-flow condition and analyzed for different classes of organic compounds, including many from the U.S. Environmental Protection Agency's priority pollutant list. Bottom sediment also was analyzed for trace elements typically associated with urban runoff. Trace-element concentrations in the less than 63 micrometer fraction of Amazon Creek bottom-sediment samples were compared with baseline concentrations (expected 95 percent confidence range) for soils from the Western United States and with concen- trations found in bottom sediment from the Willamette River Basin. Total-digestion concentrations of antimony, arsenic, cadmium, chromium, cobalt, copper, lead, manganese, mercury, nickel, silver, titanium, and zinc were enriched at some or all sites sampled. Whole-water samples from some sites contained concentrations of several chlorophenoxy-acid herbicides, the organophosphorus insecticide diazinon, and several semivolatile priority pollutants. Classes of compounds not detected in whole-water samples included carbamate insecticides, triazine and other nitrogen-containing herbicides, and purgeable organic compounds. Bottom-sediment samples contained many organochlorine compounds, including chlordane, DDT plus metabolites, dieldrin, endrin, heptachlor epoxide (a metabolite of heptachlor), and PCBs at some or all sites sampled. Twenty-four of 54 semivolatile compounds were detected in bottom- sediment samples at some or all sites sampled.

  10. Loggers and Forest Fragmentation: Behavioral Models of Road Building in the Amazon Basin

    Science.gov (United States)

    Arima, Eugenio Y.; Walker, Robert T.; Perz, Stephen G.; Caldas, Marcellus

    2005-01-01

    Although a large literature now exists on the drivers of tropical deforestation, less is known about its spatial manifestation. This is a critical shortcoming in our knowledge base since the spatial pattern of land-cover change and forest fragmentation, in particular, strongly affect biodiversity. The purpose of this article is to consider emergent patterns of road networks, the initial proximate cause of fragmentation in tropical forest frontiers. Specifically, we address the road-building processes of loggers who are very active in the Amazon landscape. To this end, we develop an explanation of road expansions, using a positive approach combining a theoretical model of economic behavior with geographic information systems (GIs) software in order to mimic the spatial decisions of road builders. We simulate two types of road extensions commonly found in the Amazon basin in a region: showing the fishbone pattern of fragmentation. Although our simulation results are only partially successful, they call attention to the role of multiple agents in the landscape, the importance of legal and institutional constraints on economic behavior, and the power of GIs as a research tool.

  11. Outbreak of Cutaneous Leishmaniasis in Peruvian Military Personnel Undertaking Training Activities in the Amazon Basin, 2010

    Science.gov (United States)

    Oré, Marianela; Sáenz, Eliana; Cabrera, Rufino; Sanchez, Juan F.; De Los Santos, Maxy B.; Lucas, Carmen M.; Núñez, Jorge H.; Edgel, Kimberly A.; Sopan, Justino; Fernández, Jorge; Carnero, Andres M.; Baldeviano, G. Christian; Arrasco, Juan C.; Graf, Paul C. F.; Lescano, Andres G.

    2015-01-01

    Military personnel deployed to the Amazon Basin are at high risk for cutaneous leishmaniasis (CL). We responded to an outbreak among Peruvian Army personnel returning from short-term training in the Amazon, conducting active case detection, lesion sample collection, and risk factor assessment. The attack rate was 25% (76/303); the incubation period was 2–36 weeks (median = 8). Most cases had one lesion (66%), primarily ulcerative (49%), and in the legs (57%). Real-time polymerase chain reaction (PCR) identified Leishmania (Viannia) braziliensis (59/61 = 97%) and L. (V.) guyanensis (2/61 = 3%). Being male (risk ratio [RR] = 4.01; P = 0.034), not wearing long-sleeve clothes (RR = 1.71; P = 0.005), and sleeping in open rooms (RR = 1.80; P = 0.009) were associated with CL. Sodium stibogluconate therapy had a 41% cure rate, less than previously reported in Peru (∼ 70%; P < 0.001). After emphasizing pre-deployment education and other basic prevention measures, trainees in the following year had lower incidence (1/278 = 0.4%; P < 0.001). Basic prevention can reduce CL risk in deployed militaries. PMID:26078320

  12. Outbreak of Cutaneous Leishmaniasis in Peruvian Military Personnel Undertaking Training Activities in the Amazon Basin, 2010.

    Science.gov (United States)

    Oré, Marianela; Sáenz, Eliana; Cabrera, Rufino; Sanchez, Juan F; De Los Santos, Maxy B; Lucas, Carmen M; Núñez, Jorge H; Edgel, Kimberly A; Sopan, Justino; Fernández, Jorge; Carnero, Andres M; Baldeviano, G Christian; Arrasco, Juan C; Graf, Paul C F; Lescano, Andres G

    2015-08-01

    Military personnel deployed to the Amazon Basin are at high risk for cutaneous leishmaniasis (CL). We responded to an outbreak among Peruvian Army personnel returning from short-term training in the Amazon, conducting active case detection, lesion sample collection, and risk factor assessment. The attack rate was 25% (76/303); the incubation period was 2-36 weeks (median = 8). Most cases had one lesion (66%), primarily ulcerative (49%), and in the legs (57%). Real-time polymerase chain reaction (PCR) identified Leishmania (Viannia) braziliensis (59/61 = 97%) and L. (V.) guyanensis (2/61 = 3%). Being male (risk ratio [RR] = 4.01; P = 0.034), not wearing long-sleeve clothes (RR = 1.71; P = 0.005), and sleeping in open rooms (RR = 1.80; P = 0.009) were associated with CL. Sodium stibogluconate therapy had a 41% cure rate, less than previously reported in Peru (~70%; P < 0.001). After emphasizing pre-deployment education and other basic prevention measures, trainees in the following year had lower incidence (1/278 = 0.4%; P < 0.001). Basic prevention can reduce CL risk in deployed militaries.

  13. Mercury contamination in humans linked to river chemistry in the Amazon basin

    Energy Technology Data Exchange (ETDEWEB)

    Silva-Forsberg, M.C. [Indiana Univ., Bloomington, IN (United States). CIPEC-Center for the study of Institutions, Populations and Environmental Change; Forsberg, B.R.; Zeidemann, V.K. [Instituto Nacional de Pesquisas da Amazonia (INPA), Manaus, AM (Brazil). Coordenacao de Pesquisas em Ecologia

    1999-09-01

    Dissolved organic carbon (DOC) and pH are key variables influencing mercury levels in freshwater biota. DOC complexes with mercury, facilitates its transport to and accumulation in aquatic ecosystems. Low pH favors the methylation and bioaccumulation of mercury in aquatic food chains. Mercury concentrations in predatory fish tend to be positively correlated with DOC and negatively correlated with pH. We encountered a similar pattern for fish-eating human populations in the upper Rio Negro, a black water tributary of the Amazon river. The highest levels of human contamination were encountered in effluents with exceptionally high DOC and low pH. When data from other Amazonian tributaries were included, a general pattern emerged. Hair mercury was positively correlated with river DOC and negatively correlated with pH. No clear effect of gold-mining activities was encountered. The results demonstrate the importance of river chemistry in determining the pattern of mercury contamination in the Amazon basin 15 refs, 2 figs, 1 tab

  14. Moenkhausia celibela: a new species from the Amazon basin, Brazil (Characiformes: Characidae).

    Science.gov (United States)

    Marinho, M M F; Langeani, F

    2010-09-01

    A new species of Characidae, Moenkhausia celibela, is described from the Rio Amazonas at Santarém, Rio Maraú, several localities in the Rio Tapajós, Rio Curuá-Una, Rio Xingu and Rio Jari, all from the Amazon basin, Brazil. The new species is distinguished from its congeners, except species included in Géry's 1992 Moenkhausia lepidura group, by presenting a dark blotch on the upper caudal-fin lobe, and the lower lobe is hyaline or light grey. Moenkhausia celibela is distinguished from the species of the M. lepidura group by the absence of a humeral spot and the presence of a roughly triangular and dark spot at the caudal-fin base, extending posteriorly along the middle caudal-fin rays, and distinctly separate from the spot on the upper caudal-fin lobe. PMID:20840617

  15. New species of Cyphocharax (Characiformes: Curimatidae from the upper rio Negro, Amazon basin

    Directory of Open Access Journals (Sweden)

    Bruno F. Melo

    2014-06-01

    Full Text Available A new species of Cyphocharax, Curimatidae, apparently endemic to the blackwater upper rio Negro of the Amazon basin in northern Brazil, is described.The new species is readily distinguished from its congeners by the presence of a distinctly longitudinally elongate, posteriorly vertically expanding patch of dark pigmentation along the midlateral surface of the caudal peduncle, with the patch extending from the base of the middle caudal-fin rays anteriorly past the vertical through the posterior terminus of the adipose fin. The new species additionally differs from all congeners in details of body and fin pigmentation and meristic and morphometric ratios. Evidence for the assignment of the species to Cyphocharax and the occurrence of other species of the Curimatidae apparently endemic to the upper rio Negro catchment is discussed.

  16. Trend and uncertainty in spatial-temporal patterns of hydrological droughts in the Amazon basin

    Science.gov (United States)

    Lopes, A. V.; Chiang, J. C. H.; Thompson, S. A.; Dracup, J. A.

    2016-04-01

    Spatial-temporal patterns of hydrological droughts in the Amazon basin are derived from drought indices computed from existing streamflow data. Principal component analysis and Monte Carlo simulations are employed to account for the uncertainty and overcome the limitations of missing data in streamflow records. Results show that northern and southern subbasins differ in drought trends and in patterns of correlation between drought indices and climate anomalies originating from the Pacific (El Niño-Southern Oscillation) and Atlantic (differences in sea surface temperature across the equator) Oceans. A significant trend toward more intense droughts is found in the southern subbasins, which is highly correlated to tropical Atlantic Ocean sea surface temperature anomalies. That drying trend might have distinct causes in each subbasin and can lead to potential intensification of regional impacts.

  17. Chromosomal diversity in three species of electric fish (Apteronotidae, Gymnotiformes) from the Amazon Basin.

    Science.gov (United States)

    Silva, Fernando Henrique Ramos; Pieczarka, Julio Cesar; Cardoso, Adauto Lima; da Silva, Patrícia Corrêa; de Oliveira, Jonas Alves; Nagamachi, Cleusa Yoshiko

    2014-10-01

    Cytogenetic studies were carried out on samples of Parapteronotus hasemani, Sternarchogiton preto and Sternarchorhamphus muelleri (Apteronotidae, Gymnotiformes) from the Amazon basin. The first two species exhibited both a 2n = 52 karyotype, but differed in their karyotypic formulae, distribution of constitutive heterochromatin, and chromosomal location of the NOR. The third species, Sternarchorhamphus muelleri, was found to have a 2n = 32 karyotype. In all three species the DAPI and chromomycin A3 staining results were consistent with the C-banding results and nucleolar organizer region (NOR) localization. The 18S rDNA probe confirmed that there was only one pair of ribosomal DNA cistron bearers per species. The telomeric probe did not reveal interstitial telomeric sequences (ITS). The karyotypic differences among these species can be used for taxonomic identification. These data will be useful in future studies of these fishes and help understanding the phylogenetic relationships and chromosomal evolution of the Apteronotidae.

  18. Formaldehyde and Glyoxal Measurements as Tracers of Oxidation Chemistry in the Amazon Basin

    Science.gov (United States)

    Thayer, M. P.; Dorris, M. R.; Keutsch, F. N.; Springston, S. R.; Jimenez, J. L.; Palm, B. B.; Seco, R.; Kim, S.; Yee, L.; Wernis, R. A.; Goldstein, A. H.; Isaacman-VanWertz, G. A.; Liu, Y.; Martin, S. T.

    2015-12-01

    Formaldehyde (HCHO) and glyoxal (CHOCHO) are important tracers for oxidative processes in the atmosphere such as oxidation of volatile organic compounds (VOCs) and production of HO2 radicals by photolysis or reaction with OH. Products of VOC oxidation and radical cycling, such as aerosols and tropospheric ozone, have direct impacts on human health. During the Green Ocean Amazon campaign (GoAmazon2014/5), HCHO and CHOCHO measurements were obtained together with OH, RO2+HO2, CO, CO2, O3, NOx, (o)VOCs, and aerosol particle size distribution. HCHO concentration was measured by the Madison FIber Laser-Induced Fluorescence (FILIF) instrument, while CHOCHO concentrations were collected by the Madison Laser-Induced Phosphorescence (Mad-LIP) instrument. Here we present data collected during 2014 at the T3 field site, 60 km to the west of Manaus, Brazil (3°12'47.82"S, 60°35'55.32"W). The T3 GoAmazon site varies between sampling strictly pristine (biogenic) emissions and influence from anthropogenic emissions from Manaus, depending on meteorological conditions. Here we present overall trends and regimes observed during the campaign, with a focus on HCHO, CHOCHO, and related species within the context of VOC oxidation and secondary pollutant production. We acknowledge the support from the Central Office of the Large Scale Biosphere Atmosphere Experiment in Amazonia (LBA), the Instituto Nacional de Pesquisas da Amazonia (INPA), and the Universidade do Estado do Amazonia (UEA). The work was conducted under 001030/2012-4 of the Brazilian National Council for Scientific and Technological Development (CNPq). Data were collected from the Atmospheric Radiation Measurement (ARM) Climate Research Facility, a U.S. Department of Energy Office of Science user facility sponsored by the Office of Biological and Environmental Research. Additionally, we acknowledge logistical support from the ARM Climate Research Facility. Additional funding from: NSF GRFP DGE-1256259, and NSF AGS-1051338

  19. Monitoring water level in large trans-boundary ungauged basins with altimetry: the example of ENVISAT over the Amazon basin

    Science.gov (United States)

    Seyler, Frederique; Calmant, Stephane; da Silva, Joecila; Filizola, Naziano; Roux, Emmanuel; Cochonneau, Gerard; Vauchel, Philippe; Bonnet, Marie-Paule

    2009-01-01

    Brasil and Bolivia have water plans projects on the Beni-Madeira river, a major tributary of the Amazon. There are four main tributaries to the Rio Madeira: the Guapore, the Mamore and the Beni rivers into the Bolivian territory, and the Madre de Dios River crossing the North of Bolivia, coming from Peru. Most parts of these rivers are very far from the Andean capital cities of Bolivia and Peru, unreachable for long periods of time. Very few gauging stations are in operation, either for the Bolivian or the Peruvian part, most of them being located at the Andes piedmont or near the confluence at the Brazilian border as they form the Madeira river. This situation is exemplary of large transboundary basins in the tropical part of the world. We have computed 39 water level time series using ENVISAT altimetry data over the four tributaries of the Madeira and the Madeira itself. We present a preliminary study mostly conducted onto the Guapore river, in order to assess the quality of these time series for a variety of situations, but mostly narrow and meandering riverbeds. Comparison between water levels variation in the mainstream and within the inundations plains and lakes are drawn. We conclude by the perspectives offered by the combined use of radar altimetry and SAR imagery for the global monitoring of water resources, in large tropical transboundary basins.

  20. Two soil hydrology formulations of ORCHIDEE (version Trunk.rev1311 tested for the Amazon basin

    Directory of Open Access Journals (Sweden)

    M. Guimberteau

    2014-01-01

    to a satellite-based dataset. The dry-season length between 4 and 7 months over the entire Amazon basin was found to be critical in distinguishing differences in hydrological feedbacks between the soil and the vegetation cover simulated by the two soil models. Overall, the 11 layer soil diffusion scheme provided little improvement in simulated hydrology on average over the wet tropical Amazonian sub-basins but a more significant improvement over the drier sub-basins. However, the use of the 11 layer soil diffusion scheme might become critical for assessments of future hydrological changes, especially in southern regions of the Amazon basin where longer dry season and more severe droughts are expected in the next century.

  1. The nitrogen budget for different forest types in the central Congo Basin

    Science.gov (United States)

    Bauters, Marijn; Verbeeck, Hans; Cizungu, Landry; Boeckx, Pascal

    2016-04-01

    Characterization of fundamental processes in different forest types is vital to understand the interaction of forests with their changing environment. Recent data analyses, as well as modeling activities have shown that the CO2 uptake by terrestrial ecosystems strongly depends on site fertility, i.e. nutrient availability. Accurate projections of future net forest growth and terrestrial CO2 uptake thus necessitate an improved understanding on nutrient cycles and how these are coupled to the carbon (C) cycle in forests. This holds especially for tropical forests, since they represent about 40-50% of the total carbon that is stored in terrestrial vegetation, with the Amazon basin and the Congo basin being the largest two contiguous blocks. However, due to political instability and reduced accessibility in the central Africa region, there is a strong bias in scientific research towards the Amazon basin. Consequently, central African forests are poorly characterized and their role in global change interactions shows distinct knowledge gaps, which is important bottleneck for all efforts to further optimize Earth system models explicitly including this region. Research in the Congo Basin region should combine assessments of both carbon stocks and the underlying nutrient cycles which directly impact the forest productivity. We set up a monitoring network for carbon stocks and nitrogen fluxes in four different forest types in the Congo Basin, which is now operative. With the preliminary data, we can get a glimpse of the differences in nitrogen budget and biogeochemistry of African mixed lowland rainforest, monodominant lowland forest, mixed montane forest and eucalypt plantations.

  2. Astyanax ajuricaba: a new species from the Amazon basin in Brazil (Characiformes: Characidae

    Directory of Open Access Journals (Sweden)

    Manoela M. F. Marinho

    2009-06-01

    Full Text Available A new Astyanax species is described from several localities in the rio Negro, rio Solimões and lower rio Tapajós basins, Amazon basin, Brazil. The new species is distinguished from all remaining characids by its unique color pattern consisting of the combination of presence of a conspicuous, narrow dark midlateral stripe, a well-developed vertically-elongated dark humeral spot, and upper caudal-fin lobe and middle caudal-fin rays dark, with a rounded clear ocellated spot present at anterior third of caudal-fin lobe.Uma nova espécie de Astyanax é descrita de diversas localidades nas bacias dos rios Negro, Solimões e baixo Tapajós, bacia Amazônica, Brasil. A nova espécie pode ser distinguida de todos os demais Characidae por um padrão de colorido único, que consiste na combinação da presença de uma linha médio-lateral estreita e escura, uma mácula umeral escura bem desenvolvida e verticalmente alongada e o lobo superior da nadadeira caudal e raios medianos escuros, com uma mancha ocelada clara presente no terço anterior do lobo.

  3. Water discharge estimates from large radar altimetry datasets in the Amazon basin

    Directory of Open Access Journals (Sweden)

    A. C. V. Getirana

    2012-06-01

    Full Text Available In this study, we evaluate the use of a large radar altimetry dataset as a complementary gauging network capable of providing water discharge in ungauged regions within the Amazon basin. A rating-curve-based methodology is adopted to derive water discharge from altimetric data provided by Envisat at 444 virtual stations (VS. The stage-discharge relations at VS are built based on radar altimetry and outputs from a global flow routing scheme. In order to quantify the impact of modeling uncertainties on rating-curve based discharges, another experiment is performed using simulated discharges derived from a simplified data assimilation procedure. Discharge estimates at 90 VS are evaluated against observations during the curve fitting calibration (2002–2005 and evaluation (2006–2008 periods, resulting in mean relative RMS errors as high as 52% and 12% for experiments without and with assimilation, respectively. Without data assimilation, uncertainty of discharge estimates can be mostly attributed to forcing errors at smaller scales, generating a positive correlation between performance and drainage area. Mean relative errors (RE of altimetry-based discharges varied from 15% to 92% for large and small drainage areas, respectively. Rating curves produced a mean RE of 54% versus 68% from model outputs. Assimilating discharge data decreases the mean RE from 68% to 12%. These results demonstrate the feasibility of applying the proposed methodology to the regional or global scales. Also, it is shown the potential of satellite altimetry for predicting water discharge in poorly-gauged and ungauged river basins.

  4. Characterization, analysis and dating of archaeological ceramics from the Amazon basin through nuclear techniques

    International Nuclear Information System (INIS)

    The aim of this work is to contribute to the research in the reconstruction of part of the pre-history of the Amazon Basin by means of an analytical methods combined with multivariate analysis, given a analytic basis that can be continued by the archaeological work, through the identification, classification, provenance and dating the ceramics found in different archaeological sites of the Hydro graphic Basin of the Purus river. Neutron activation analysis in conjunction multivariate statistical methods were used for the identification and classification and thermoluminescence was used for the dating. Chemical composition results were in better agreement with archaeological classification for the archaeologically define Iquiri, Quinan and Xapuri phases and less characteristics the Iaco and Jacuru archaeological phase were not well characterized. An homogeneous group was established by most of the samples collected from the Los Angeles Archaeological Site (LA) and was distinct from all the other groups analysed. The provenance studies made with ceramics collected at this site shows that they were made with clay from nearby river (Rio Ina). From the LA ceramics dating the average date of site occupation was 1660 years. The ceramic dating results from the external wall of a circular earth wall construction confirm the relation with the local pre-history. Beyond the Acre material two urns were dated from the Archaeological Site Morro Grande and Sao Jose at Araruama, Rio de Janeiro. (author)

  5. Study of ceramics from circular archaeological sites of Amazonic Basin by geochemical methods: dating and characterization

    International Nuclear Information System (INIS)

    The aim of this work is to examine by means of characterization and dating pottery recently discovery inside archaeological sites recognized with circular earth structure in Acre State - Brazil which may contribute to the research in the reconstruction of part of the pre-history of the Amazonic Basin. These sites are located mainly in the Hydrographic Basin of High Purus River. Three of them were strategic chosen which provide the ceramics: Lobao, in Sena Madureira County at north; Alto Alegre, in Rio Branco County at east and Xipamanu I, in Xapuri County at south. The X-ray diffraction mineral analysis made possible to identify two types of crystal structures of ceramic minerals: quartz and M-Kaolinite. Neutron activation analysis in conjunction with multivariate statistical methods were applied for the ceramic characterization and classification. An homogeneous group was established by all sherds collected from Alto Alegre and was distinct from all the other two groups analyzed. Some of the sherds collected from Xipamanu I appeared in Lobao's urns, probably because they had the same fabrication process. The Lobao's urns presented a homogeneous group. Geochronology of these materials was carried out by Thermoluminescence. The Xipamanu I was the oldest site and Lobao the youngest. The average age of Xipamanu I and Alto Alegre were 2600 and 2070 years respectively. The average age of of occupation was 400 years to Alto Alegre and 970 years to Xipamanu I. The most probably date for Lobao was 1880 years. (author)

  6. Trace elements in aerosols from background air pollution monitoring stations in the Amazon Basin using nuclear-related techniques

    International Nuclear Information System (INIS)

    In order to study the natural release of aerosol particles by the Amazon Basin tropical rain forest, the composition and size distribution of biogenic aerosol particles were analyzed. The role of the atmospheric emissions from the Amazon Basin rain forest in the global atmosphere will be investigated. The atmosphere was studied in long-term sampling stations in three different locations. The elemental composition of aerosol particles released during biomass burning was also measured in several different ecosystems, from primary forest to Savannah. One of the main focuses was to identify and quantify important physical and chemical processes in the generation, transformation and deposition of aerosol particles. Also important was to obtain a better understanding of natural aerosol sources concerning identification, their characteristics and strength, to be able to understand the natural chemistry in the atmosphere on a global scale. 36 refs, 3 figs, 3 tabs

  7. Genetic diversity of vaccine candidate antigens in Plasmodium falciparum isolates from the Amazon basin of Peru

    Directory of Open Access Journals (Sweden)

    Lucas Carmen M

    2008-05-01

    Full Text Available Abstract Background Several of the intended Plasmodium falciparum vaccine candidate antigens are highly polymorphic and could render a vaccine ineffective if their antigenic sites were not represented in the vaccine. In this study, characterization of genetic variability was performed in major B and T-cell epitopes within vaccine candidate antigens in isolates of P. falciparum from Peru. Methods DNA sequencing analysis was completed on 139 isolates of P. falciparum collected from endemic areas of the Amazon basin in Loreto, Peru from years 1998 to 2006. Genetic diversity was determined in immunological important regions in circumsporozoite protein (CSP, merozoite surface protein-1 (MSP-1, apical membrane antigen-1 (AMA-1, liver stage antigen-1 (LSA-1 and thrombospondin-related anonymous protein (TRAP. Alleles identified by DNA sequencing were aligned with the vaccine strain 3D7 and DNA polymorphism analysis and FST study-year pairwise comparisons were done using the DnaSP software. Multilocus analysis (MLA was performed and average of expected heterozygosity was calculated for each loci and haplotype over time. Results Three different alleles for CSP, seven for MSP-1 Block 2, one for MSP-1 Block 17, three for AMA-1 and for LSA-1 each and one for TRAP were identified. There were 24 different haplotypes in 125 infections with complete locus typing for each gene. Conclusion Characterization of the genetic diversity in Plasmodium isolates from the Amazon Region of Peru showed that P. falciparum T and B cell epitopes in these antigens have polymorphisms more similar to India than to Africa. These findings are helpful in the formulation of a vaccine considering restricted repertoire populations.

  8. Neotropical Hemerodromia Meigen (Diptera: Empididae), a world of discovery I: new generic record and new species from Brazilian Amazon Basin.

    Science.gov (United States)

    Câmara, J T; Plant, A R; Rafael, J A

    2014-12-08

    Ten new species of Hemerodromia Meigen, 1822 are described and illustrated from the Brazilian state of Amazonas: H. amazonensis sp. nov., H. breviradia sp. nov., H. cercusdilatata sp. nov., H. collini sp. nov., H. epandriocurvialis sp. nov., H. jauensis sp. nov., H. lamellata sp. nov., H. longilamellata sp. nov., H. maturaca sp. nov., H. smithi sp. nov. This is the first record of the genus from the Brazilian Amazon Basin.

  9. Palm oil production in Peruvian Amazon Basin. A case study of current effects and emerging localized alternatives in Loreto district

    OpenAIRE

    Jensen, Charlotte Bratberget

    2015-01-01

    An analysis of palm oil production in the Peruvian Amazon basin was carried out in a systemic way, as part of a whole, with its complexities. With an agroecological perspective, the social, ecological and economic effects of this production are discussed. Additionally, alternatives that could better fulfil the necessities of farmers were explored. The oil palm, Elaeis guineensis, originally from West Africa, is a common plant in an enormous industry that is extensive in South East Asia, ma...

  10. Transport of North African dust from the Bodélé depression to the Amazon Basin: a case study

    Directory of Open Access Journals (Sweden)

    Y. Ben-Ami

    2010-08-01

    Full Text Available Through long-range transport of dust, the North-African desert supplies essential minerals to the Amazon rain forest. Since North African dust reaches South America mostly during the Northern Hemisphere winter, the dust sources active during winter are the main contributors to the forest. Given that the Bodélé depression area in southwestern Chad is the main winter dust source, a close link is expected between the Bodélé emission patterns and volumes and the mineral supply flux to the Amazon.

    Until now, the particular link between the Bodélé and the Amazon forest was based on sparse satellite measurements and modeling studies. In this study, we combine a detailed analysis of space-borne and ground data with reanalysis model data and surface measurements taken in the central Amazon during the Amazonian Aerosol Characterization Experiment (AMAZE-08 in order to explore the validity and the nature of the proposed link between the Bodélé depression and the Amazon forest.

    This case study follows the dust events of 11–16 and 18–27 February 2008, from the emission in the Bodélé over West Africa (most likely with contribution from other dust sources in the region the crossing of the Atlantic Ocean, to the observed effects above the Amazon canopy about 10 days after the emission. The dust was lifted by surface winds stronger than 14 m s−1, usually starting early in the morning. The lofted dust, mixed with biomass burning aerosols over Nigeria, was transported over the Atlantic Ocean, and arrived over the South American continent. The top of the aerosol layer reached above 3 km, and the bottom merged with the boundary layer. The arrival of the dusty air parcel over the Amazon forest increased the average concentration of aerosol crustal elements by an order of magnitude.

  11. Phorcotabanus cinereus (Wiedemann, 1821 (Diptera, Tabanidae, an ornithophilic species of Tabanid in Central Amazon, Brazil

    Directory of Open Access Journals (Sweden)

    Limeira-de-Oliveira Francisco

    2002-01-01

    Full Text Available In Central Amazon, Brazil, the tabanid Phorcotabanus cinereus (Wiedemann was recorded attacking the native duck Cairina moschata (Linnaeus (Anseriformes, Anatidae. The flight and behavior of the tabanid during the attacks and the host's defenses were videotaped and analyzed in slow motion. The tabanid was recorded flying rapidly around the heads of the ducks before landing. Landing always took place on the beak, and then the tabanid walked to the fleshy caruncle on the basal part of the beak to bite and feed. Firstly the duck defends itself through lateral harsh head movements, and then, when it is being bitten, it defends itself by rubbing its head on the body, or dipping the head into water, when swimming. If disturbed, the fly resumed the same pattern of flight as before and would generally try to land again on the same host and bite in the same place. This feeding activity was observed predominantly between 9:30 am and 4:30 pm and always in open areas, near aquatic environments, from June 1996 to January 1997, the dry season in Central Amazon. To test the attractiveness of other animals to P. cinereus, mammals, caimans and domestic and wild birds were placed in suitable habitat and the response of P. cinereus observed. P. cinereus did not attack these animals, suggesting that this species has a preference for ducks, which are plentiful in the region.

  12. Seroprevalence of Toxoplasma gondii in free-living Amazon river dolphins (Inia geoffrensis) from central Amazon, Brazil

    Science.gov (United States)

    Toxoplasma gondii is an important pathogen in aquatic mammals and its presence in these animals may indicate water contamination of aquatic environment by oocysts. Serum samples from 95 dolphins from free-living Amazon River dolphins (Inia geoffrensis) from Sustainable Development Reserve Mamirauá (...

  13. Seroprevalence of Toxoplasma gondii in free-living amazon river dolphins (Inia geoffrensis) from central Amazon, Brazil

    Science.gov (United States)

    Toxoplasma gondii is an important pathogen in aquatic mammals and its presence in these animals may indicate water contamination of aquatic environment by oocysts. Serum samples from 95 dolphins from free-living Amazon River dolphins (Inia geoffrensis) from Sustainable Development Reserve Mamirauá (...

  14. Genetic structure and historical diversification of catfish Brachyplatystoma platynemum (Siluriformes: Pimelodidae) in the Amazon basin with implications for its conservation.

    Science.gov (United States)

    Ochoa, Luz Eneida; Pereira, Luiz Henrique G; Costa-Silva, Guilherme Jose; Roxo, Fábio F; Batista, Jacqueline S; Formiga, Kyara; Foresti, Fausto; Oliveira, Claudio

    2015-05-01

    Brachyplatystoma platynemum is a catfish species widely distributed in the Amazon basin. Despite being considered of little commercial interest, the decline in other fish populations has contributed to the increase in the catches of this species. The structure, population genetic variability, and evolutionary process that have driven the diversification of this species are presently unknown. Considering that, in order to better understand the genetic structure of this species, we analyzed individuals from seven locations of the Amazon basin using eight molecular markers: control region and cytochrome b mtDNA sequences, and a set of six nuclear microsatellite loci. The results show high levels of haplotype diversity and point to the occurrence of two structured populations (Amazon River and the Madeira River) with high values for F ST. Divergence time estimates based on mtDNA indicated that these populations diverged about 1.0 Mya (0.2-2.5 Mya 95% HPD) using cytochrome b and 1.4 Mya (0.2-2.7 Mya 95% HPD) using control region. During that time, the influence of climate changes and hydrological events such as sea level oscillations and drainage isolation as a result of geological processes in the Pleistocene may have contributed to the current structure of B. platynemum populations, as well as of differences in water chemistry in Madeira River. The strong genetic structure and the time of genetic divergence estimated for the groups may indicate the existence of strong structure populations of B. platynemum in the Amazon basin.

  15. East Central Uplift Belt of Junggar Basin

    Institute of Scientific and Technical Information of China (English)

    1996-01-01

    @@ Mosuowandong ( Z3 ) and Dongdaohaizi (Z4) are two bidding blocks located in the east part of central uplift Belt, the hinterland of Junggar Basin. Xinjiang Uygur Autonomous Region. It totally covers an area of 8 100km2. Topographically, the two blocks are quite gentle with elevation of 380-400 m on average. The north part is desert and the south area is good for farming. There are three ephemeral streams flowing across the desert from south to north. The ground water is buried at the depth ranging from 6 to 8 m. It belongs to continental climate with the annually averaged precipitation of 80 mm. The traffic is rather convenient in the south part of both blocks. There are several sand-paved roads and two asphalt roads connected with the highway from Karamay to Urumqi City.

  16. Detailed bathymetric surveys in the central Indian Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Kodagali, V.N.; KameshRaju, K.A.; Ramprasad, T.; George, P.; Jaisankar, S.

    Over 420,000 line kilometers of echo-sounding data was collected in the Central Indian Basin. This data was digitized, merged with navigation data and a detailed bathymetric map of the Basin was prepared. The Basin can be broadly classified...

  17. Detection of long-term trends in monthly hydro-climatic records of Colombia and the Amazon River basin through Empirical Mode Decomposition

    Science.gov (United States)

    Carmona, A. M.; Poveda, G.

    2011-12-01

    We search for long-term trends in 25- to 50-year records of monthly rainfall (100 stations), average river discharges (42 stations), and mean and minimum air temperature records (37 stations) in Colombia, as well as monthly records in 29 rain gauges within the Amazon River basin. Time series of average monthly river discharges are selected from 10 Colombian river basins with gauging stations located downstream along the main channel. The Empirical Mode Decomposition (EMD) method is used as a filtering process to decompose a given time series into a finite number of intrinsic mode functions (IMF), assuming that diverse simple oscillatory modes of different frequencies coexist in the series, and that the residual captures the long-term trend of the record. The Mann-Kendall test for autocorrelated data is used to assess the statistical significance of the trends, and the Sen test is used for the magnitude of the trends. Results show that 62% of monthly river discharge series exhibit decreasing trends between 0.01-1.92 m3/s yr-1. The identified trends are strongly consistent downstream, albeit with contrasting results for the ratios between the magnitude of the trend and mean discharges. Most minimum temperature series (87%) show increasing trends [0.01-0.08°C yr-1]. Results on precipitation are inconclusive as monthly records exhibit a mixed pattern of increasing (41%, between 0.1-7.0 mm yr-1) and decreasing (44%, between 0.1-7.4 mm yr-1) trends, except for the Pacific region, which shows clear-cut positive trends, consistently with an increasing trend identified in the strength of the Chocó low-level jet winds over the Pacific coast of Colombia, the main moisture advection mechanism into the region. Maximum trend magnitudes in precipitation records on the Amazon basin were found to be decreasing (53%, between 0.04 -9.1 mm yr-1), mostly around the basin's central and south-eastern regions. The highest decreasing trend magnitude in the Amazon was found to be -9.1mm

  18. Geographical genetics of Pseudoplatystoma punctifer (Castelnau, 1855) (Siluriformes, Pimelodidae) in the Amazon Basin.

    Science.gov (United States)

    Telles, M P C; Collevatti, R G; Braga, R S; Guedes, L B S; Castro, T G; Costa, M C; Silva-Júnior, N J; Barthem, R B; Diniz-Filho, J A F

    2014-05-09

    Geographical genetics allows the evaluation of evolutionary processes underlying genetic variation within and among local populations and forms the basis for establishing more effective strategies for biodiversity conservation at the population level. In this study, we used explicit spatial analyses to investigate molecular genetic variation (estimated using 7 microsatellite markers) of Pseudoplatystoma punctifer, by using samples obtained from 15 localities along the Madeira River and Solimões, Amazon Basin. A high genetic diversity was observed associated with a relatively low FST (0.057; P < 0.001), but pairwise FST values ranged from zero up to 0.21 when some pairs of populations were compared. These FST values have a relatively low correlation with geographic distances (r = 0.343; P = 0.074 by Mantel test), but a Mantel correlogram revealed that close populations (up to 80 km) tended to be more similar than expected by chance (r = 0.360; P = 0.015). The correlogram also showed a exponential-like decrease of genetic similarity with distance, with a patch-size of around 200 km, compatible with isolation-by-distance and analogous processes related to local constraints of dispersal and spatially structured levels of gene flow. The pattern revealed herein has important implications for establishing strategies to maintain genetic diversity in the species, especially considering the threats due to human impacts caused by building large dams in this river system.

  19. DNA barcodes of Rosy Tetras and allied species (Characiformes: Characidae: Hyphessobrycon) from the Brazilian Amazon basin.

    Science.gov (United States)

    Castro Paz, Francis Paola; Batista, Jacqueline da Silva; Porto, Jorge Ivan Rebelo

    2014-01-01

    DNA barcoding can be an effective tool for fast and accurate species-level identification based on sequencing of the mitochondrial cytochrome c oxidase subunit (COI) gene. The diversity of this fragment can be used to estimate the richness of the respective species. In this study, we explored the use of DNA barcoding in a group of ornamental freshwater fish of the genus Hyphessobrycon. We sequenced the COI from 10 species of Hyphessobrycon belonging to the "Rosy Tetra Clade" collected from the Amazon and Negro River basins and combined our results with published data. The average conspecific and congeneric Kimura 2-parameter distances were 2.3% and 19.3%, respectively. Six of the 10 species were easily distinguishable by DNA barcoding (H. bentosi, H. copelandi, H. eques, H. epicharis, H. pulchrippinis, and H. sweglesi), whereas the remaining species (H. erythrostigma, H. pyrrhonotus, H. rosaceus and H. socolofi) lacked reciprocal monophyly. Although the COI gene was not fully diagnostic, the discovery of distinct evolutionary units in certain Hyphessobrycon species under the same specific epithet as well as haplotype sharing between different species suggest that DNA barcoding is useful for species identification in this speciose genus.

  20. Monitoring mercury exposure in reproductive aged women inhabiting the Tapajós river basin, Amazon.

    Science.gov (United States)

    de Oliveira Corvelo, Tereza Cristina; Oliveira, Érika Abdon Fiquene; de Parijós, Amanda Magno; de Oliveira, Claudia Simone Baltazar; do Socorro Pompeu de Loiola, Rosane; de Araújo, Amélia A; da Costa, Carlos Araújo; de Lima Silveira, Luiz Carlos; da Conceição Nascimento Pinheiro, Maria

    2014-07-01

    Among Amazonian communities, exposure to methylmercury is associated mainly with fish consumption that may affect fetal development in pregnant women. Therefore a temporal assessment was performed to assess the exposure of reproductive aged women to mercury who reside in the riparian communities of São Luís do Tapajós and Barreiras located in the Tapajós basin of the Brazilian Amazon from 1999 to 2012. The total mercury concentration in the 519 hair samples was assessed by cold vapor atomic absorption spectrometry. Data analysis showed that the average total mercury concentration decreased from 1.066 to 0.743 μg/g in those years. In 1999 the proportion of volunteers with mercury levels ≥ 10 μg/g was approximately 68 %. In general, exposure to mercury decreased among women of reproductive age, but the potential risks to reproduction and human health is still an issue as 22 % of the woman continued showing high mercury levels (≥ 10 μg/g) in 2012.

  1. Rate of kaolinite transformation in lateritic soils of the middle Amazon basin

    Science.gov (United States)

    Balan, E.; Allard, T.; Fritsch, E.; Selo, M.; Falgueres, C.; Chabaux, F.; Pierret, M.; Calas, G.

    2006-05-01

    The rate of kaolinite transformation in lateritic soils is a key parameter to understand the dynamics of tropical environments. Slow rates may support the use of the isotopic composition of kaolinite in paleoclimatic reconstructions. In contrast, high rates of dissolution and precipitation support a significant contribution of kaolinite to the biogeochemical cycles of Si and Al. We have investigated the kaolinite transformation in a lateritic profile of the middle Amazon basin using infrared spectroscopy and electron paramagnetic resonance. The upward decrease of kaolinite structural order indicates the dissolution of underlying sedimentary kaolinites and the more recent precipitation of soil kaolinites. A direct assessment of the age of kaolinites was obtained using their concentration in radiation induced defects (RID), which accumulate in the mineral structure over the course of time. The underlying sedimentary kaolin provides apparent ages older than 20 Ma, whereas kaolinite samples from the lateritic soil provide apparent ages ranging from 10 to 6 Ma. The high RID content of these lateritic kaolinites implies that they cannot be representative of present day weathering conditions. Their contribution to the rapid biogeochemical cycling of silica in lateritic topsoils is thus questionable.

  2. Bioaccumulation of methylmercury in fish tissue from the Roosevelt River, Southwestern Amazon basin

    Directory of Open Access Journals (Sweden)

    Marcelo Rodrigues dos Anjos

    2016-06-01

    Full Text Available Mercury is a major pollutant in the Amazon River system, and its levels in fish and human hair are usually above the limit recommended by health agencies. The objective of this study was to analyze the methylmercury (MeHg concentration in fish tissue from the Roosevelt River. The river's water velocity, depth, pH, temperature, electrical conductivity, dissolved oxygen and substrate type were measured, and fifty specimens distributed in 14 fish species were collected. A total of 64.3% of the sampled species were of the order Characiform and 71.4% of the species were carnivores. Fifty percent of the species had MeHg concentrations above threshold limit (Hg-T 0.5 mg kg-1 established for food by the World Health Organization. Cichla monoculus had the highest value of MeHg (2.45 mg kg-1. The MeHg concentration in fish varied according to dietary habits. The study also found bioaccumulation of MeHg in fish tissue in the following descending order: carnivorous > detritivorous > frugivore. Low significant correlations were found between fish weight or length and MeHg. Further studies on MeHg contamination are recommended in tissues of fish consumed in human riverine communities in the Roosevelt River Basin.

  3. Widespread Amazon forest tree mortality from a single cross-basin squall line event

    Science.gov (United States)

    Negrón-Juárez, Robinson I.; Chambers, Jeffrey Q.; Guimaraes, Giuliano; Zeng, Hongcheng; Raupp, Carlos F. M.; Marra, Daniel M.; Ribeiro, Gabriel H. P. M.; Saatchi, Sassan S.; Nelson, Bruce W.; Higuchi, Niro

    2010-08-01

    Climate change is expected to increase the intensity of extreme precipitation events in Amazonia that in turn might produce more forest blowdowns associated with convective storms. Yet quantitative tree mortality associated with convective storms has never been reported across Amazonia, representing an important additional source of carbon to the atmosphere. Here we demonstrate that a single squall line (aligned cluster of convective storm cells) propagating across Amazonia in January, 2005, caused widespread forest tree mortality and may have contributed to the elevated mortality observed that year. Forest plot data demonstrated that the same year represented the second highest mortality rate over a 15-year annual monitoring interval. Over the Manaus region, disturbed forest patches generated by the squall followed a power-law distribution (scaling exponent α = 1.48) and produced a mortality of 0.3-0.5 million trees, equivalent to 30% of the observed annual deforestation reported in 2005 over the same area. Basin-wide, potential tree mortality from this one event was estimated at 542 ± 121 million trees, equivalent to 23% of the mean annual biomass accumulation estimated for these forests. Our results highlight the vulnerability of Amazon trees to wind-driven mortality associated with convective storms. Storm intensity is expected to increase with a warming climate, which would result in additional tree mortality and carbon release to the atmosphere, with the potential to further warm the climate system.

  4. Using GRACE Total Water Storage Changes to constrain River Routing Models in the Amazon River basin

    Science.gov (United States)

    de Linage, C.; Lo, M.; Famiglietti, J. S.; Ray, R. L.; Beighley, R. E.

    2010-12-01

    The GRACE mission provides monthly to 10-day maps of Total Water Storage Anomalies corresponding to the vertically integrated land water storage (soil moisture and groundwater) as well as storage in river channels and floodplains (surface waters). The surface water component is an important contributor to total water storage in the Amazon River basin as shown by improved agreement between GRACE observations and model simulations when runoff is routed through the river network as compared to no river routing. We use the Community Land Model version 3.5 to model land water storage along with runoff by accounting for a simple ground water model. Surface and subsurface runoff predictions are then routed using two different routing models: a simple cell-to-cell routing scheme (e.g. Branstetter and Famiglietti, 1999) and the Hillslope River Routing (Beighley et al. 2010). We evaluate model performances against the spatio-temporal variations of GRACE data by carrying out a Singular Value Decomposition of the cross-covariance matrix. We also compare the two models in the light of their respective intrinsic capabilities. We finally investigate the impact of the precipitation data on model outputs by using TRMM products instead of GLDAS (CMAP) products.

  5. Recent shift from forest to savanna burning in the Amazon Basin observed by satellite

    International Nuclear Information System (INIS)

    The numbers of fires detected on forest, savanna and transition lands during the 2002–10 biomass burning seasons in Amazonia are shown using fire count data and co-located land cover classifications from the Moderate Resolution Imaging Spectroradiometer (MODIS). The ratio of forest fires to savanna fires has varied substantially over the study period, with a maximum ratio of 0.65:1 in 2005 and a minimum ratio of 0.27:1 in 2009, with the four lowest years occurring in 2007–10. The burning during the droughts of 2007 and 2010 is attributed to a higher number of savanna fires relative to the drought of 2005. A decrease in the regional mean single scattering albedo of biomass burning aerosols, consistent with the shift from forest to savanna burning, is also shown. During the severe drought of 2010, forest fire detections were lower in many areas compared with 2005, even though the drought was more severe in 2010. This result suggests that improved fire management practices, including stricter burning regulations as well as lower deforestation burning, may have reduced forest fires in 2010 relative to 2005 in some areas of the Amazon Basin. (letter)

  6. Abiotic variability among different aquatic systems of the central Amazon floodplain during drought and flood events.

    Science.gov (United States)

    Affonso, A G; Queiroz, H L; Novo, E M L M

    2015-11-01

    This paper examines water properties from lakes, (depression lakes, sensu Junk et al., 2012), channels (scroll lakes with high connectivity, sensu Junk et al., 2012) and paleo-channels (scroll lakes with low connectivity-sensu Junk et al., 2012, locally called ressacas) located in Mamirauá Sustainable Development Reserve, in Central Amazon floodplain, Amazonas, Brazil. We analysed surface temperature, conductivity, pH, dissolved oxygen, turbidity, transparency, suspended inorganic and organic matter, chlorophyll-a, pheophytin, total nitrogen, total phosphorus, organic and inorganic carbon in 2009 high water phase, 2009 and 2010 low water phases. Multivariate statistical analyses of 24 aquatic systems (6 ressacas, 12 lakes and 6 channels, 142 samples) were applied to the variables in order to: 1) quantify differences among aquatic system types; 2) assess how those differences are affected in the different phases of the hydrological year. First, we analysed the entire set of variables to test for differences among phases of the hydrological year and types of aquatic systems using a PERMANOVA two-way crossed design. The results showed that the all measured limnological variables are distinct regarding both factors: types of aquatic systems and hydrological phases. In general, the magnitude and amplitude of all variables were higher in the low water phase than in the high water phase, except for water transparency in all aquatic system's types. PERMANOVA showed that the differences between aquatic system's types and hydrological phases of all variables were highly significant for both main factors (type and phase) and for the type x phase interaction. Limnological patterns of Amazon floodplain aquatic systems are highly dynamic, dependent on the surrounding environment, flood pulse, main river input and system type. These patterns show how undisturbed systems respond to natural variability in such a diverse environment, and how distinct are those aquatic systems

  7. Basin-wide variations in Amazon forest structure and function are mediated by both soils and climate

    Directory of Open Access Journals (Sweden)

    C. A. Quesada

    2012-06-01

    Full Text Available Forest structure and dynamics vary across the Amazon Basin in an east-west gradient coincident with variations in soil fertility and geology. This has resulted in the hypothesis that soil fertility may play an important role in explaining Basin-wide variations in forest biomass, growth and stem turnover rates.

    Soil samples were collected in a total of 59 different forest plots across the Amazon Basin and analysed for exchangeable cations, carbon, nitrogen and pH, with several phosphorus fractions of likely different plant availability also quantified. Physical properties were additionally examined and an index of soil physical quality developed. Bivariate relationships of soil and climatic properties with above-ground wood productivity, stand-level tree turnover rates, above-ground wood biomass and wood density were first examined with multivariate regression models then applied. Both forms of analysis were undertaken with and without considerations regarding the underlying spatial structure of the dataset.

    Despite the presence of autocorrelated spatial structures complicating many analyses, forest structure and dynamics were found to be strongly and quantitatively related to edaphic as well as climatic conditions. Basin-wide differences in stand-level turnover rates are mostly influenced by soil physical properties with variations in rates of coarse wood production mostly related to soil phosphorus status. Total soil P was a better predictor of wood production rates than any of the fractionated organic- or inorganic-P pools. This suggests that it is not only the immediately available P forms, but probably the entire soil phosphorus pool that is interacting with forest growth on longer timescales.

    A role for soil potassium in modulating Amazon forest dynamics through its effects on stand-level wood density was also detected. Taking this into account, otherwise enigmatic variations in stand-level biomass across the

  8. Basin-wide variations in Amazon forest structure and function are mediated by both soils and climate

    Science.gov (United States)

    Quesada, C. A.; Phillips, O. L.; Schwarz, M.; Czimczik, C. I.; Baker, T. R.; Patiño, S.; Fyllas, N. M.; Hodnett, M. G.; Herrera, R.; Almeida, S.; Alvarez Dávila, E.; Arneth, A.; Arroyo, L.; Chao, K. J.; Dezzeo, N.; Erwin, T.; di Fiore, A.; Higuchi, N.; Honorio Coronado, E.; Jimenez, E. M.; Killeen, T.; Lezama, A. T.; Lloyd, G.; López-González, G.; Luizão, F. J.; Malhi, Y.; Monteagudo, A.; Neill, D. A.; Núñez Vargas, P.; Paiva, R.; Peacock, J.; Peñuela, M. C.; Peña Cruz, A.; Pitman, N.; Priante Filho, N.; Prieto, A.; Ramírez, H.; Rudas, A.; Salomão, R.; Santos, A. J. B.; Schmerler, J.; Silva, N.; Silveira, M.; Vásquez, R.; Vieira, I.; Terborgh, J.; Lloyd, J.

    2012-06-01

    Forest structure and dynamics vary across the Amazon Basin in an east-west gradient coincident with variations in soil fertility and geology. This has resulted in the hypothesis that soil fertility may play an important role in explaining Basin-wide variations in forest biomass, growth and stem turnover rates. Soil samples were collected in a total of 59 different forest plots across the Amazon Basin and analysed for exchangeable cations, carbon, nitrogen and pH, with several phosphorus fractions of likely different plant availability also quantified. Physical properties were additionally examined and an index of soil physical quality developed. Bivariate relationships of soil and climatic properties with above-ground wood productivity, stand-level tree turnover rates, above-ground wood biomass and wood density were first examined with multivariate regression models then applied. Both forms of analysis were undertaken with and without considerations regarding the underlying spatial structure of the dataset. Despite the presence of autocorrelated spatial structures complicating many analyses, forest structure and dynamics were found to be strongly and quantitatively related to edaphic as well as climatic conditions. Basin-wide differences in stand-level turnover rates are mostly influenced by soil physical properties with variations in rates of coarse wood production mostly related to soil phosphorus status. Total soil P was a better predictor of wood production rates than any of the fractionated organic- or inorganic-P pools. This suggests that it is not only the immediately available P forms, but probably the entire soil phosphorus pool that is interacting with forest growth on longer timescales. A role for soil potassium in modulating Amazon forest dynamics through its effects on stand-level wood density was also detected. Taking this into account, otherwise enigmatic variations in stand-level biomass across the Basin were then accounted for through the

  9. Insights from Integrative Systematics Reveal Cryptic Diversity in Pristimantis Frogs (Anura: Craugastoridae) from the Upper Amazon Basin.

    Science.gov (United States)

    Ortega-Andrade, H Mauricio; Rojas-Soto, Octavio R; Valencia, Jorge H; Espinosa de Los Monteros, Alejandro; Morrone, Juan J; Ron, Santiago R; Cannatella, David C

    2015-01-01

    Pluralistic approaches to taxonomy facilitate a more complete appraisal of biodiversity, especially the diversification of cryptic species. Although species delimitation has traditionally been based primarily on morphological differences, the integration of new methods allows diverse lines of evidence to solve the problem. Robber frogs (Pristimantis) are exemplary, as many of the species show high morphological variation within populations, but few traits that are diagnostic of species. We used a combination of DNA sequences from three mitochondrial genes, morphometric data, and comparisons of ecological niche models (ENMs) to infer a phylogenetic hypothesis for the Pristimantis acuminatus complex. Molecular phylogenetic analyses revealed a close relationship between three new species-Pristimantis enigmaticus sp. nov., P. limoncochensis sp. nov. and P. omeviridis sp. nov.-originally confused with Pristimantis acuminatus. In combination with morphometric data and geographic distributions, several morphological characters such as degree of tympanum exposure, skin texture, ulnar/tarsal tubercles and sexual secondary characters (vocal slits and nuptial pads in males) were found to be useful for diagnosing species in the complex. Multivariate discriminant analyses provided a successful classification rate for 83-100% of specimens. Discriminant analysis of localities in environmental niche space showed a successful classification rate of 75-98%. Identity tests of ENMs rejected hypotheses of niche equivalency, although not strongly because the high values on niche overlap. Pristimantis acuminatus and P. enigmaticus sp. nov. are distributed along the lowlands of central-southern Ecuador and northern Peru, in contrast with P. limoncochensis sp. nov. and P. omeviridis sp. nov., which are found in northern Ecuador and southern Colombia, up to 1200 m in the upper Amazon Basin. The methods used herein provide an integrated framework for inventorying the greatly underestimated

  10. Insights from Integrative Systematics Reveal Cryptic Diversity in Pristimantis Frogs (Anura: Craugastoridae from the Upper Amazon Basin.

    Directory of Open Access Journals (Sweden)

    H Mauricio Ortega-Andrade

    Full Text Available Pluralistic approaches to taxonomy facilitate a more complete appraisal of biodiversity, especially the diversification of cryptic species. Although species delimitation has traditionally been based primarily on morphological differences, the integration of new methods allows diverse lines of evidence to solve the problem. Robber frogs (Pristimantis are exemplary, as many of the species show high morphological variation within populations, but few traits that are diagnostic of species. We used a combination of DNA sequences from three mitochondrial genes, morphometric data, and comparisons of ecological niche models (ENMs to infer a phylogenetic hypothesis for the Pristimantis acuminatus complex. Molecular phylogenetic analyses revealed a close relationship between three new species-Pristimantis enigmaticus sp. nov., P. limoncochensis sp. nov. and P. omeviridis sp. nov.-originally confused with Pristimantis acuminatus. In combination with morphometric data and geographic distributions, several morphological characters such as degree of tympanum exposure, skin texture, ulnar/tarsal tubercles and sexual secondary characters (vocal slits and nuptial pads in males were found to be useful for diagnosing species in the complex. Multivariate discriminant analyses provided a successful classification rate for 83-100% of specimens. Discriminant analysis of localities in environmental niche space showed a successful classification rate of 75-98%. Identity tests of ENMs rejected hypotheses of niche equivalency, although not strongly because the high values on niche overlap. Pristimantis acuminatus and P. enigmaticus sp. nov. are distributed along the lowlands of central-southern Ecuador and northern Peru, in contrast with P. limoncochensis sp. nov. and P. omeviridis sp. nov., which are found in northern Ecuador and southern Colombia, up to 1200 m in the upper Amazon Basin. The methods used herein provide an integrated framework for inventorying the greatly

  11. Paleo-environment in the upper amazon basin during early to middle Miocene times

    Science.gov (United States)

    van Soelen, Els; Hoorn, Carina; Santos, Roberto V.; Dantas, Elton L.; Sinninghe Damsté, Jaap S.; Kim, Jung-Hyun

    2014-05-01

    The Amazon River has the largest catchment in the world and is responsible for the largest water discharge from land to the ocean. The river system that flows from the Andes to the Atlantic Equatorial Margin exists since the late Miocene, and results from Andean uplift which strongly affected erosion/deposition and major flow patterns in northern South-America. Two outcrop sites from the Solimões basin, Mariñame (17.7-16.1 Ma) and Los Chorros (14.2-12.7 Ma), may shed light on the inland paleo-environmental conditions during a period of active Andean uplift in the early to middle Miocene. Earlier works revealed the Mariñame outcrops to represent a river born in Amazonia. Instead the Los Chorros outcrops are relics of the Amazon River system, characterized by extensive wetlands consisting of swamps, shallow lakes, crevasse splays channels and crevasse-delta lakes (e.g. Hoorn et al., 2010). The freshwater ecosystems alternate with some intervals that are rich in marine palynomorphs (such as dinocysts), mangrove pollen, brackish tolerant molluscs and ostracods, which indicate brackish conditions and a marine influence. It is thought that these marine incursion are related to phases of global sea-level rise and rapid subsidence in the Andean foreland (Marshall & Lundberg, 1996). Still, much remains unknown about the Miocene river systems, like the extent and diversity of the wetland system and the nature of the marine incursions. To get a better understanding of the sources of the (in)organic material, geochemical methods were used. Strontium (Sr) and Neodymium (Nd) isotopes were analyzed on bulk sediments, and used for a paleo-provenance study. The Sr and Nd isotopic signature in the older section (Mariñame) is in general more radiogenic compared to the Los Chorros section. The most radiogenic values are comparable to those found nowadays in the the Precambrian Guyana shield. A Guyana sediment source would suggest a distinctly different flow direction of the major

  12. Merging plot and Landsata data to estimate the frequency distribution of Central Amazon mortality event size for landscape-scale ecosystem simulations

    Science.gov (United States)

    Di Vittorio, A. V.; Chambers, J. Q.

    2012-12-01

    Mitigation strategies and estimates of land use change emissions assume initial states of landscapes that respond to prescribed scenarios. The Amazon basin is a target for both mitigation (e.g. maintenance of old-growth forest) and land use change (e.g. agriculture), but the current states of its old-growth and secondary forest landscapes are uncertain with respect to carbon cycling. Contributing to this uncertainty in old-growth forest ecosystems is a mosaic of patches in different successional stages, with the areal fraction of any particular stage relatively constant over large temporal and spatial scales. Old-growth mosaics are generally created through ongoing effects of tree mortality, with the Central Amazon mosaic generated primarily by wind mortality. Unfortunately, estimation of generalizable frequency distributions of mortality event size has been hindered by limited spatial and temporal scales of observations. To overcome these limitations we merge field and remotely sensed tree mortality data and fit the top two candidate distributions (power law and exponential) to these data to determine the most appropriate statistical mortality model for use in landscape-scale ecosystem simulations. Our results show that the power law model better represents the distribution of mortality event size than the exponential model. We also use an individual-tree-based forest stand model to simulate a 100 ha landscape using the best fit of each candidate distribution to demonstrate the effects of different mortality regimes on above ground biomass in the Central Amazon forest mosaic. We conclude that the correct mortality distribution model is critical for robust simulation of patch succession dynamics and above ground biomass.

  13. Sr and Nd isotopes of suspended sediments from rivers of the Amazon basin

    Science.gov (United States)

    Hatting, Karina; Santos, Roberto V.; Sondag, Francis

    2014-05-01

    The Rb-Sr and Sm-Nd isotopic systems are important tools to constrain the provenance of sediment load in river systems. This study presents the isotopic composition of Sr and Nd isotopes and major and minor elements in suspended sediments from the Marañón-Solimões, Amazonas and Beni-Madeira rivers. The data were used to constrain the source region of the sediments and to better understand the main seasonal and spatial transport processes within the basin based on the variations of the chemical and isotopic signals. They also allow establishing a relationship between sediment concentrations and flow rate values. The study presents data collected during a hydrological year between 2009 and 2010. The Marañón-Solimões River presents low Sr isotopic values (0.7090-0.7186), broad EpslonNd(0) range (-15.17 to -8.09) and Nd model (TDM) ages varying from 0.99 to 1.81 Ga. Sources of sediments to the Marañón-Solimões River include recent volcanic rocks in northern Peru and Ecuador, as well as rocks with long crustal residence time and carbonates from the Marañón Basin, Peru. The Beni-Madeira River has more radiogenic Sr isotope values (0.7255-0.7403), more negative EpslonNd(0) values (-20.46 to -10.47), and older Nd isotope model ages (from 1.40 to 2.35 Ga) when compared to the Marañón-Solimões River. These isotope data were related to the erosion of Paleozoic and Cenozoic foreland basins that are filled with Precambrian sediments derived from the Amazonian Craton. These basins are located in Bolivian Subandina Zone. The Amazon River presents intermediate isotopic values when compared to those found in the Marañón-Solimões and Beni-Madeira rivers. Its Sr isotope ratios range between 0.7193 and 0.7290, and its EpslonNd(0) values varies between -11.09 and -9.51. The Nd isotope model ages of the suspended sediments vary between 1.28 and 1.77 Ga. Concentrations of soluble and insoluble elements indicate a more intense weathering activity in sediments of the Beni

  14. Modeling Potential Impacts of Planting Palms or Tree in Small Holder Fruit Plantations on Ecohydrological Processes in the Central Amazon

    Directory of Open Access Journals (Sweden)

    Norbert Kunert

    2015-07-01

    Full Text Available Native fruiting plants are widely cultivated in the Amazon, but little information on their water use characteristics can be found in the literature. To explore the potential impacts of plantations on local to regional water balance, we studied plant water use characteristics of two native fruit plants commonly occurring in the Amazon region. The study was conducted in a mixed fruit plantation containing a dicot tree species (Cupuaçu, Theobroma grandiflorum and a monocot palm species (Açai, Euterpe oleracea close to the city of Manaus, in the Central Amazon. Scaling from sap flux measurements, palms had a 3.5-fold higher water consumption compared to trees with a similar diameter. Despite the high transpiration rates of the palms, our plantation had only one third of the potential water recycling capacity of natural forests in the area. Converting natural forest into such plantations will thus result in significantly higher runoff rates.

  15. Predicting biomass of hyperdiverse and structurally complex Central Amazon forests - a virtual approach using extensive field data

    Science.gov (United States)

    Magnabosco Marra, D.; Higuchi, N.; Trumbore, S. E.; Ribeiro, G. H. P. M.; dos Santos, J.; Carneiro, V. M. C.; Lima, A. J. N.; Chambers, J. Q.; Negrón-Juárez, R. I.; Holzwarth, F.; Reu, B.; Wirth, C.

    2015-09-01

    Old-growth forests are subject to substantial changes in structure and species composition due to the intensification of human activities, gradual climate change and extreme weather events. Trees store ca. 90 % of the total AGB above-ground biomass in tropical forests and AGB estimation models are crucial for forest management and conservation. In the Central Amazon, predicting AGB at large spatial-scales is a challenging task due to the heterogeneity of successional stages, high tree species diversity and inherent variations in allometry and architecture. We parameterized generic AGB estimation models applicable across species and a wide range of structural and compositional variation related to species sorting into height layers as well as frequent natural disturbances. We used 727 trees from 101 genera and at least 135 species harvested in a contiguous forest near Manaus, Brazil. Sampling from this dataset we assembled six scenarios designed to span existing gradients in floristic composition and size distribution in order to select models that best predict AGB at the landscape-level across successional gradients. We found that good individual tree model fits do not necessarily translate into good predictions of AGB at the landscape level. When predicting AGB (dry mass) over scenarios using our different models and an available pantropical model, we observed systematic biases ranging from -31 % (pantropical) to +39 %, with RMSE root-mean-square error values of up to 130 Mg ha-1 (pantropical). Our first and second best models had both low mean biases (0.8 and 3.9 %, respectively) and RMSE (9.4 and 18.6 Mg ha-1) when applied over scenarios. Predicting biomass correctly at the landscape-level in complex tropical forests, especially allowing good performance at the margins of data availability for model parametrization, requires the inclusion of predictors related to species architecture. The model of interest should comprise the floristic composition and size

  16. Consequence of forest-to-pasture conversion on CH4 fluxes in the Brazilian Amazon Basin

    Science.gov (United States)

    Steudler, Paul A.; Melillo, Jerry M.; Feigl, Brigitte J.; Neill, Christopher; Piccolo, Marisa C.; Cerri, Carlos C.

    1996-08-01

    Methane (CH4) fluxes between soils and the atmosphere were measured in two tropical forest-to-pasture chronosequences in the state of Rondônia, Brazil. Forest soils always consumed atmospheric CH4 with maximum uptake rates in the dry season. Pasture soils consumed atmospheric CH4 during the dry season, but at lower rates than those in the forests. When soil moisture increased in the pasture soils, they became a source of CH4 to the atmosphere. Integrated over the year, forest soils were a net sink of approximately 470 mg CH4-C/m2, while pastures were a net source of about 270 mg CH4-C/m2. Thus forest-to-pasture conversion resulted in a net source of CH4 from the soil of about 1 g CH4/m2/yr. The total pasture-related CH4 release for the entire Brazilian Amazon increased from 0.8 Tg CH4 in 1970 to about 2.5 Tg CH4 in 1990, with a maximum of 3.1 Tg CH4/yr in 1988. Soils accounted for a small part (about 5%) of the total CH4 release from the basin, while biomass burning and cattle emissions accounted for 95%. The average rate of increase in CH4 emission from pastures was about 0.2 Tg CH4/yr between 1975 and 1988. This represents between 12% and 14% of the global average rate of change in tropospheric CH4 content for this time period.

  17. Elemental composition of aerosol particles from two atmospheric monitoring stations in the Amazon Basin

    International Nuclear Information System (INIS)

    One key region for the study of processes that are changing the composition of the global atmosphere is the Amazon Basin tropical rain forest. The high rate of deforestation and biomass burning is emitting large amounts of gases and fine-mode aerosol particles to the global atmosphere. Two background monitoring stations are operating continuously measuring aerosol composition, at Cuiaba, and Serra do Navio. Fine- and coarse-mode aerosol particles are being collected using stacked filter units. Particle induced X-ray emission (PIXE) was used to measure concentrations of up to 21 elements: Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Se, Br, Rb, Sr, Zr, and Pb. The elemental composition was measured at the new PIXE facility from the University of Sao Paulo, using a dedicated 5SDH tandem Pelletron nuclear accelerator. Absolute principal factor analysis (APFA) has derived absolute elemental source profiles. At the Serra do Navio sampling site a very clean background aerosol is being observed. Biogenic aerosol dominates the fine-mode mass concentration, with the presence of K, P, S, Cl, Zn, Br, and FPM. Three components dominate the aerosol composition: Soil dust particles, the natural biogenic release by the forest, and a marine aerosol component. At the Cuiaba site, during the dry season, a strong component of biomass burning is observed. An aerosol mass concentration up to 120 μg/m3 was measured. APFA showed three components: Soil dust (Al, Ca, Ti, Mn, Fe), biomass burning (soot, FPM, K, Cl) and natural biogenic particles (K, S, Ca, Mn, Zn). The fine-mode biogenic component of both sites shows remarkable similarities, although the two sampling sites are 3000 km apart. Several essential plant nutrients like P, K, S, Ca, Ni and others are transported in the atmosphere as a result of biomass burning processes. (orig.)

  18. Preliminary Measurements Of N2O Partial Pressures In Rivers of Amazon Basin, Brazil

    Science.gov (United States)

    Oliveira, C. B.; Rasera, M. F.; Krusche, A. V.; Victoria, R. L.; Richey, J. E.; Cunha, H. B.; Gomes, B. M.

    2006-12-01

    The concentrations of nitrous oxide (N2O), an important component of the greenhouse effect and with a long residence time in the atmosphere, have significantly increased in this century. The reasons for this atmospheric increase in N2O are still partially unexplained. This uncertainty is worse in relation to aquatic environments. Here we report on preliminary measurements of N2O partial pressures in rivers of the Amazon basin. The study areas are in the state of Rondonia (rivers Ji Parana, Urupa, Comemoracao and Pimenta Bueno) and Amazonas (rivers Solimoes and Negro). The rivers were sampled from October 2005 to April 2006, using with immersion pumps, lowered in the middle of the channel to 60% of total depth. Water was pumped directly into a 1 l plastic bottle, which was overflown three times before closing. Using syringes, 60 ml of N2 were injected into the bottle, simultaenously to the withdrawn of 60 ml of sample. N2O was extracted into these 60 ml of N2 by shaking vigorously for 2 minutes. With the same syringes, the gas was taken from the bottles and injected into sealed evacuated 25 ml vials. Atmospheric samples were taken from one meter above the water column and stored the same way. N2O partial pressures were determined on a Shimadzu GC-14 Green House Gas Analyzer. All rivers showed little variations in N2O partial pressures. Average values in the rivers of Rondonia were around 0.41 ± 0.07 μ atm (n=46), whereas the Solimoes and Negro rivers, in the state of Amazonas, showed values around 0.43 ± 0.08 μ atm (n=131). Atmospheric averages were approximately 0.34 ± 0.04 μ atm (n=58) and 0.32 ± 0.03 μ atm (n=134) in the states of Rondonia and Amazonas, respectively. This means that, although these waters are supersatured in CO2, making evasive fluxes of this gas an important component of the C cycle in this basin, the same does not occur in the N cycle. Small differences in partial pressures of N2O between water and air will result in small fluxes of

  19. An evaluation eMergetics of Itacoatiara's city in the central Amazon, their plywood, and cultivated plain of basin of Madeira's river; Uma avaliacao eMergetica da cidade de Itacoatiara na Amazonia Central, sua industria de compensado e laminado e a varzea da bacia do rio Madeira

    Energy Technology Data Exchange (ETDEWEB)

    Comar, Vito

    1994-12-01

    The plywood production system of Itacoatiara's industry and the wooden extraction impact of cultivated plain of basin of Madeira's river are presented. The incorporated energy flows - eMergy are evaluated by the models mathematical simulation, which applies to specific indices derivation aiming at the comparison with other similar processes. Itacoatiara's city was going analyzed regarding the industry load energetics and of others urban components.

  20. Methane emissions from floodplains in the Amazon Basin: challenges in developing a process-based model for global applications

    Science.gov (United States)

    Ringeval, B.; Houweling, S.; van Bodegom, P. M.; Spahni, R.; van Beek, R.; Joos, F.; Röckmann, T.

    2014-03-01

    Tropical wetlands are estimated to represent about 50% of the natural wetland methane (CH4) emissions and explain a large fraction of the observed CH4 variability on timescales ranging from glacial-interglacial cycles to the currently observed year-to-year variability. Despite their importance, however, tropical wetlands are poorly represented in global models aiming to predict global CH4 emissions. This publication documents a first step in the development of a process-based model of CH4 emissions from tropical floodplains for global applications. For this purpose, the LPX-Bern Dynamic Global Vegetation Model (LPX hereafter) was slightly modified to represent floodplain hydrology, vegetation and associated CH4 emissions. The extent of tropical floodplains was prescribed using output from the spatially explicit hydrology model PCR-GLOBWB. We introduced new plant functional types (PFTs) that explicitly represent floodplain vegetation. The PFT parameterizations were evaluated against available remote-sensing data sets (GLC2000 land cover and MODIS Net Primary Productivity). Simulated CH4 flux densities were evaluated against field observations and regional flux inventories. Simulated CH4 emissions at Amazon Basin scale were compared to model simulations performed in the WETCHIMP intercomparison project. We found that LPX reproduces the average magnitude of observed net CH4 flux densities for the Amazon Basin. However, the model does not reproduce the variability between sites or between years within a site. Unfortunately, site information is too limited to attest or disprove some model features. At the Amazon Basin scale, our results underline the large uncertainty in the magnitude of wetland CH4 emissions. Sensitivity analyses gave insights into the main drivers of floodplain CH4 emission and their associated uncertainties. In particular, uncertainties in floodplain extent (i.e., difference between GLC2000 and PCR-GLOBWB output) modulate the simulated emissions by a

  1. The Role of Lakes and Rivers as Sources of Evaporated Water to the Atmosphere in the Amazon Basin

    International Nuclear Information System (INIS)

    Due its magnitude, the water cycle in the Amazon basin plays a key role in the biogeochemical cycles of the region, as well as affecting regional and global climate. Despite its importance, the Amazon region is under constant pressure because of its natural resources, and deforestation accounts for a major part of this human influence. The continental freshwater system in the region is not highly threatened, although human occupation follows roads and rivers pathways. Several urban and agricultural activities take place by the river's banks. Over the past 30 years, riparian regions have been cleared for agriculture and human settlements, and the floodplains are being intensely used for cattle grazing during the low water season and for fishing during high water, putting at risk highly diverse and abundant fisheries stocks in the region as whole. The floodplains are an important spawning habitat for several species. Thus understanding of biogeochemical and nutrient dynamic of the floodplains is crucial to sustain the ecological health of those systems. Identification of physical process patterns (i.e, evaporation, wind, water current) and sources of water to the floodplains are key to this knowledge. The main objective of this work was to investigate the role of the Amazon floodplains lakes and rivers as sources of evaporated water to the atmosphere. (author)

  2. Seasonality and interannual variability of CH4 fluxes from the eastern Amazon Basin inferred from atmospheric mole fraction profiles

    Science.gov (United States)

    Basso, Luana S.; Gatti, Luciana V.; Gloor, Manuel; Miller, John B.; Domingues, Lucas G.; Correia, Caio S. C.; Borges, Viviane F.

    2016-01-01

    The Amazon Basin is an important region for global CH4 emissions. It hosts the largest area of humid tropical forests, and around 20% of this area is seasonally flooded. In a warming climate it is possible that CH4 emissions from the Amazon will increase both as a result of increased temperatures and precipitation. To examine if there are indications of first signs of such changes we present here a 13 year (2000-2013) record of regularly measured vertical CH4 mole fraction profiles above the eastern Brazilian Amazon, sensitive to fluxes from the region upwind of Santarém (SAN), between SAN and the Atlantic coast. Using a simple mass balance approach, we find substantial CH4 emissions with an annual average flux of 52.8 ± 6.8 mg CH4 m-2 d-1 over an area of approximately 1 × 106 km2. Fluxes are highest in two periods of the year: in the beginning of the wet season and during the dry season. Using a CO:CH4 emission factor estimated from the profile data, we estimated a contribution of biomass burning of around 15% to the total flux in the dry season, indicating that biogenic emissions dominate the CH4 flux. This 13 year record shows that CH4 emissions upwind of SAN varied over the years, with highest emissions in 2008 (around 25% higher than in 2007), mainly during the wet season, representing 19% of the observed global increase in this year.

  3. A note on incipient spilitisation of central Indian basin basalts

    Digital Repository Service at National Institute of Oceanography (India)

    Karisiddaiah, S.M.; Iyer, S.D.

    Rocks dredged in the vicinity of the 79 degrees E fracture zone, in the Central Indian Basin, are sub-alkaline basalts, which are regarded as precursors to spilites. The minerals identified are mainly albitic plagioclase, augite, olivine, and less...

  4. New occurrences of Australasian microtektites in the Central Indian Basin

    Digital Repository Service at National Institute of Oceanography (India)

    ShyamPrasad, M.

    Thirty-three microtektites have been recovered from four different sites in the Central Indian Basin. Based on their physical properties, geographical occurrence and chemical composition, they are identified as belonging to the Australasian tektite...

  5. Factors Controlling Respiration Rates and Respired Carbon Dioxide Signatures in Riverine Ecosystems of the Amazon Basin

    Science.gov (United States)

    Ellis, E. E.; Richey, J. E.; Aufdenkampe, A. K.; Quay, P. D.; Krusche, A. V.; Alin, S. R.

    2006-12-01

    This study examined the processes controlling respiration rates observed in streams and rivers throughout the Amazon basin during the dry season by substituting spatial coverage for experimental manipulation. Throughout the Brazilian states of Amazonas and Acre, respiration rates ranged from 0.066 to 1.45 μM/hr of O2 consumed. In situ respiration was positively correlated with pH (r2=0.60), with pH values ranging from 3.95 to 8.57. Although the concentration of bulk size fractions of organic matter(dissolved organic carbon (DOC), fine particulate organic carbon, and coarse particulate organic carbon) were uncorrelated with both pH and respiration, respiration was positively correlated with the percentage of DOC that was less than 5 kDa as determined by centrifuge ultrafiltration (r2=0.52). No correlation was observed for the less than 100 kDa fraction. Further, pH was also correlated with the percentage of DOC in the <5 kDa fraction (r2=0.86), as the <5 kDa fraction increased from 34% in acidic blackwater streams to 91% in more basic whitewater rivers. These results suggest that low molecular weight organic matter (LMWOM, <5 kDa) is labile and supports higher respiration rates as compared to high molecular weight organic matter, and that pH may control the size distribution of dissolved organic matter. Further, at high pH sites with high respiration rates, net primary production ranged from 3.54 to 13.5 μM/hr of O2 produced. These rates suggest that higher pH sites are dominated by in situ production, resulting in high yields of LMWOM, which is rapidly consumed during the dry season. The 13C of respired CO2 was monitored during bottle incubations to characterize the source of organic matter being respired. Values ranged from -15.2 to -27.0‰, similar to the 13C of DIC at each site, indicating that respiration is a key process controlling the δ13C of the DIC. Furthermore, there is a positive correlation between the δ13C of respired CO2 and respiration rate (r2

  6. Potamotrygon limai, sp. nov., a new species of freshwater stingray from the upper Madeira River system, Amazon basin (Chondrichthyes: Potamotrygonidae).

    Science.gov (United States)

    Fontenelle, João Pedro; Da Silva, João Paulo C B; De Carvalho, Marcelo R

    2014-02-18

    Potamotrygon limai, sp. nov., is described from the Jamari River, upper Madeira River system (Amazon basin), state of Rondônia, Brazil. This new species differs from congeners by presenting unique polygonal or concentric patterns formed by small whitish spots better defined over the posterior disc and tail-base regions. Potamotrygon limai, sp. nov., can be further distinguished from congeners in the same basin by other characters in combination, such as two to three rows of midtail spines converging to a single irregular row at level of caudal sting origin, proportions of head, tail and disc, patterns of dermal denticles on rostral, cranial and tail regions, among other features discussed herein. Potamotrygon limai, sp. nov., is most similar to, and occurs sympatrically with, P. scobina, and is distinguished from it by lacking ocellated spots on disc, by its characteristic polygonal pattern on posterior disc, a comparatively much shorter and broader tail, greater intensity of denticles on disc, more midtail spine rows at tail-base, and other features including size at maturity and meristic characters. Potamotrygon limai, sp. nov., is also distinguished from other species of Potamotrygon occurring in the Amazon region, except P. scobina, by presenting three angular cartilages (vs. two or one). This new species was discovered during a detailed taxonomic and morphological revision of the closely related species P. scobina, and highlights the necessity for thorough and all-embracing taxonomic studies, particularly in groups with pronounced endemism and morphological variability.

  7. Response of tree biomass and wood litter to disturbance in a Central Amazon forest.

    Science.gov (United States)

    Chambers, Jeffrey Q; Higuchi, Niro; Teixeira, Liliane M; dos Santos, Joaquim; Laurance, Susan G; Trumbore, Susan E

    2004-12-01

    We developed an individual-based stochastic-empirical model to simulate the carbon dynamics of live and dead trees in a Central Amazon forest near Manaus, Brazil. The model is based on analyses of extensive field studies carried out on permanent forest inventory plots, and syntheses of published studies. New analyses included: (1) growth suppression of small trees, (2) maximum size (trunk base diameter) for 220 tree species, (3) the relationship between growth rate and wood density, and (4) the growth response of surviving trees to catastrophic mortality (from logging). The model simulates a forest inventory plot, and tracks recruitment, growth, and mortality of live trees, decomposition of dead trees (coarse litter), and how these processes vary with changing environmental conditions. Model predictions were tested against aggregated field data, and also compared with independent measurements including maximum tree age and coarse litter standing stocks. Spatial analyses demonstrated that a plot size of approximately 10 ha was required to accurately measure wood (live and dead) carbon balance. With the model accurately predicting relevant pools and fluxes, a number of model experiments were performed to predict forest carbon balance response to perturbations including: (1) increased productivity due to CO2 fertilization, (2) a single semi-catastrophic (10%) mortality event, (3) increased recruitment and mortality (turnover) rates, and (4) the combined effects of increased turnover, increased tree growth rates, and decreased mean wood density of new recruits. Results demonstrated that carbon accumulation over the past few decades observed on tropical forest inventory plots (approximately 0.5 Mg C ha(-1) year(-1)) is not likely caused by CO2 fertilization. A maximum 25% increase in woody tissue productivity with a doubling of atmospheric CO2 only resulted in an accumulation rate of 0.05 Mg C ha(-1) year(-1) for the period 1980-2020 for a Central Amazon forest, or an

  8. Efficacy of sulfadoxine-pyrimethamine and mefloquine for the treatment of uncomplicated Plasmodium falciparum malaria in the Amazon basin of Peru

    Directory of Open Access Journals (Sweden)

    Magill Alan J.

    2004-01-01

    Full Text Available In vivo antimalarial drug efficacy studies of uncomplicated Plasmodium falciparum malaria at an isolated site in the Amazon basin of Peru bordering Brazil and Colombia showed >50% RII/RIII resistance to sulfadoxine-pyrimethamine but no evidence of resistance to mefloquine.

  9. Spatiotemporal patterns of tropical deforestation and forest degradation in response to the operation of the Tucuruí hydroelectricdam in the Amazon basin

    NARCIS (Netherlands)

    Chen, Gang; Powers, Ryan P.; Carvalho, de Luis M.T.; Mora, Brice

    2015-01-01

    The planned construction of hundreds of hydroelectric dams in the Amazon basin has the potential to provide invaluable ‘clean’ energy resources for aiding in securing future regional energy needs and continued economic growth. These mega-structures, however, directly and indirectly interfere with na

  10. Some Key Issues in Intercultural Bilingual Education Teacher Training Programmes--as Seen from a Teacher Training Programme in the Peruvian Amazon Basin.

    Science.gov (United States)

    Trapnell, Lucy A.

    2003-01-01

    Presents a critical reflection of the author's 14-year experience in the Teacher Training Program for Intercultural Bilingual Education in the Peruvian Amazon Basin, developed by a national Peruvian indigenous confederation and the Loreto state teacher training college. Focuses on ethical, political, and pedagogical challenges that intercultural…

  11. Methane emissions from floodplains in the Amazon Basin: towards a process-based model for global applications

    Directory of Open Access Journals (Sweden)

    B. Ringeval

    2013-10-01

    Full Text Available Tropical wetlands are estimated to represent about 50% of the natural wetland emissions and explain a large fraction of the observed CH4 variability on time scales ranging from glacial-interglacial cycles to the currently observed year-to-year variability. Despite their importance, however, tropical wetlands are poorly represented in global models aiming to predict global CH4 emissions. This study documents the first regional-scale, process-based model of CH4 emissions from tropical floodplains. The LPX-Bern Dynamic Global Vegetation Model (LPX hereafter was modified to represent floodplain hydrology, vegetation and associated CH4 emissions. The extent of tropical floodplains was prescribed using output from the spatially-explicit hydrology model PCR-GLOBWB. We introduced new Plant Functional Types (PFTs that explicitly represent floodplain vegetation. The PFT parameterizations were evaluated against available remote sensing datasets (GLC2000 land cover and MODIS Net Primary Productivity. Simulated CH4 flux densities were evaluated against field observations and regional flux inventories. Simulated CH4 emissions at Amazon Basin scale were compared to model simulations performed in the WETCHIMP intercomparison project. We found that LPX simulated CH4 flux densities are in reasonable agreement with observations at the field scale but with a~tendency to overestimate the flux observed at specific sites. In addition, the model did not reproduce between-site variations or between-year variations within a site. Unfortunately, site informations are too limited to attest or disprove some model features. At the Amazon Basin scale, our results underline the large uncertainty in the magnitude of wetland CH4 emissions. In particular, uncertainties in floodplain extent (i.e., difference between GLC2000 and PCR-GLOBWB output modulate the simulated emissions by a factor of about 2. Our best estimates, using PCR-GLOBWB in combination with GLC2000, lead to

  12. Optically stimulated luminescence dating of archaeological ceramics from Osvaldo and Lago Grande sites in central Amazon

    Energy Technology Data Exchange (ETDEWEB)

    Hazenfratz, Roberto; Tudela, Diego R.G.; Munita, Casimiro S., E-mail: robertohm@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Mittani, Juan C.R.; Tatumi, Sonia H. [Universidade Federal de Sao Paulo (UNIFESP), Santos, SP (Brazil)

    2013-07-01

    Thermoluminescence (TL) and optically stimulated luminescence (OSL) dating are two important techniques for dating archaeological and geological material, especially suitable for archaeological ceramics, where samples for {sup 14}C dating are not available. In this work, five pottery shards from Osvaldo and Lago Grande archaeological sites were dated by OSL. For measurements, it was used the SAR protocol. The annual dose rates were estimated by the contents of U, Th and K, determined by instrumental neutron activation analysis (INAA) of the pottery shards and clay samples near both sites. Lago Grande and Osvaldo represent a microcosm of the region, and their proximity and high density of archaeological record turn them interesting to study possible relations of cultural and/or commercial exchange. Calculations showed that the water content is an important variable that cannot be neglected in OSL dating of pottery shards from central Amazon, due to the high humidity in regional soils. The results between 867 ± 101 and 1154 ± 62 years AD agreed with the average time span for the archaeological sites occupation found in the literature. (author)

  13. Optically stimulated luminescence dating of archaeological ceramics from Osvaldo and Lago Grande sites in central Amazon

    International Nuclear Information System (INIS)

    Thermoluminescence (TL) and optically stimulated luminescence (OSL) dating are two important techniques for dating archaeological and geological material, especially suitable for archaeological ceramics, where samples for 14C dating are not available. In this work, five pottery shards from Osvaldo and Lago Grande archaeological sites were dated by OSL. For measurements, it was used the SAR protocol. The annual dose rates were estimated by the contents of U, Th and K, determined by instrumental neutron activation analysis (INAA) of the pottery shards and clay samples near both sites. Lago Grande and Osvaldo represent a microcosm of the region, and their proximity and high density of archaeological record turn them interesting to study possible relations of cultural and/or commercial exchange. Calculations showed that the water content is an important variable that cannot be neglected in OSL dating of pottery shards from central Amazon, due to the high humidity in regional soils. The results between 867 ± 101 and 1154 ± 62 years AD agreed with the average time span for the archaeological sites occupation found in the literature. (author)

  14. Length variation of Gravity-Driven systems in the Amazon River Mouth Basin: a history of carbonate-siliciclastic sedimentation and post-rift subsidence

    Science.gov (United States)

    Cruz, Alberto; Gorini, Christian; Letouzey, Jean; Suc, Jean-Pierre; Reis, Tadeu; Silva, Cleverson; Le Bouteiller, Pauline; Granjeon, Didier; Haq, Bilal; Delprat-Jannaud, Florence

    2016-04-01

    This study address the post-rift sedimentary record of the Amazon River Mouth Basin with a focus on gravity tectonics. We investigate shale detachment layers and the timing of different gravity deformation phases. Our study was based on more than 20,000 km of 2D multi-channel seismic data, 4,453 km2 of 3D multi-channel seismic data and 40 exploratory well data. A reliable age model was constructed based on biostratigraphic data. Five industry wells on the shelf/upper slope region and seven scientific wells drilled by DSDP and ODP in the distal Ceará Rise region were used for platform and deep environments correlations. This allowed us to calibrate the seismic lines and compare the sedimentation rates in different domains of the basin (e.g. shelf, slope, deep basin). In the Basin's shelf a widespread carbonate sequence dated as Late Paleocene grew up over a Latest Albian to Early Paleocene prograding clastic sequence. From the Eocene to the Late Miocene a mixed siliciclastic-carbonate aggrading megasequence developed. The first gravitational deformation event took place during the Eocene. The proximal limit (normal faults) of this this gravity-deformation system occurs along the hinge line. The major and deeper detachment layer was identified within the previously deposed Late Cretaceous-Early Paleocene stratigraphic sequence (Cenomanian-Turonian deep shale source rock?). Further downslope, during the same period a stack of thrust sheets was created. In the central part of the Basin, a second gravitational deformation phase took place from Late Oligocene to early Late Miocene. During this period the basal detachment layer (Late Cretaceous?) was reactivated and the frontal thrust sheet created ridges and piggy-back basins. From the Late Miocene to present time, a major increase in the siliciclastic sedimentation rates was evidenced in the axis of the modern Amazon Delta. A huge aggrading-prograding mega-sequence forced the expansion of a third gravitational system

  15. Ranching in the Amazon basin - Large-scale changes observed by AVHRR

    Science.gov (United States)

    Malingreau, J. P.; Tucker, C. J.

    1990-01-01

    The contribution that AVHRR data can make to resolving the controversy about the deforestation of the Amazon region is discussed. The most significant types of information which such data can supply are pointed out. A color composite is shown and discussed, showing how it points out areas of deforestation.

  16. Seasonality and interannual variability of CH4 fluxes from the eastern Amazon Basin inferred from atmospheric mole fraction profiles

    Science.gov (United States)

    Gatti, Luciana V.; Gloor, Manuel; Miller, John B.; Domingues, Lucas G.; Correia, Caio S. C.; Borges, Viviane F.

    2016-01-01

    Abstract The Amazon Basin is an important region for global CH4 emissions. It hosts the largest area of humid tropical forests, and around 20% of this area is seasonally flooded. In a warming climate it is possible that CH4 emissions from the Amazon will increase both as a result of increased temperatures and precipitation. To examine if there are indications of first signs of such changes we present here a 13 year (2000–2013) record of regularly measured vertical CH4 mole fraction profiles above the eastern Brazilian Amazon, sensitive to fluxes from the region upwind of Santarém (SAN), between SAN and the Atlantic coast. Using a simple mass balance approach, we find substantial CH4 emissions with an annual average flux of 52.8 ± 6.8 mg CH4 m−2 d−1 over an area of approximately 1 × 106 km2. Fluxes are highest in two periods of the year: in the beginning of the wet season and during the dry season. Using a CO:CH4 emission factor estimated from the profile data, we estimated a contribution of biomass burning of around 15% to the total flux in the dry season, indicating that biogenic emissions dominate the CH4 flux. This 13 year record shows that CH4 emissions upwind of SAN varied over the years, with highest emissions in 2008 (around 25% higher than in 2007), mainly during the wet season, representing 19% of the observed global increase in this year.

  17. Chronological studies of tree-rings from the Amazon Basin using thick target PIXE and proton backscattering analysis

    International Nuclear Information System (INIS)

    A tree-core sample (Aspidosperma obscurinervium, popular name: 'pequia marfim') about 161 years old (cut in 1990), from the Ducke Reserve at the Amazon Basin, Manaus, Brazil was analyzed by PIXE (Particle Induced X-ray Emission) and proton backscattering in 136 different spots along its life. Twenty-two elements plus the density of the wood were measured (C, O, H, Al, Si, P, S, Cl, K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, Sr, Co, Rb, W and Pb). Average C, O, and H results (49.77% ± 0.15%, 44.29% ± 0.14% and 5.95% ± 0.12%, respectively) compare well with literature values for the biomass in the Amazon region. The variability of trace elements along the tree rings showed important features that could be caused by modifications in the environment during the life of the tree. The well behaved variability of some trace elements (like K, P, Mn, Ca, etc.) seems to reflect the physiological response of the tree to external changes in the environment. The concentration of K varied from about 4 up to 2000 ppm in a given period of the life of the tree. The same period also shows important changes in the bulk composition and structure of the rings (e.g. C and density series). Multivariate statistical methods (cluster and factor analyses) were used for data interpretation, helping in the separation of periods of important transformations in the tree. The elemental time series is compared with historical records of regional development and with some global events that could possibly affect the tree. The period of maximum variation in the elemental concentrations appears to be related to the Brazilian rubber boom (1859-1912), responsible for several transformations in the Amazon region. In particular in the Manaus region, large development has occurred in the beginning of the 20th century, which are reflected in the results of this tree-core analysis

  18. Late Miocene onset of the Amazon River and the Amazon deep-sea fan: Evidence from the Foz do Amazonas Basin

    NARCIS (Netherlands)

    J. Figueiredo; C. Hoorn; P. van der Ven; E. Soares

    2009-01-01

    New biostratigraphic, isotopic, and well log data from exploration wells on the outer continental shelf and uppermost Amazon deep-sea fan, Brazil, reveal that the Amazon River was initiated as a transcontinental river between 11.8 and 11.3 Ma ago (middle to late Miocene), and reached its present sha

  19. Prevalence and diversity of avian malaria parasites in migratory Black Skimmers (Rynchops niger, Laridae, Charadriiformes) from the Brazilian Amazon Basin.

    Science.gov (United States)

    Roos, F L; Belo, N O; Silveira, P; Braga, E M

    2015-10-01

    The Medium Solimões River region in the Brazilian Amazon Basin is an area utilized for reproduction and nesting by a variety of species of migratory aquatic birds such as Black Skimmers (Rynchops niger). These migratory birds form mixed-species reproductive colonies with high population densities and exhibit a large range of migration routes. This study aimed to describe the prevalence and diversity of the avian malaria parasites Plasmodium and Haemoproteus in Black Skimmers, on the basis of the association between microscopic observation of blood smears and amplification of the mitochondrial cytochrome b gene (mtDNA cyt-b). The overall prevalence rates of the parasites for juvenile and adult bird specimens were 16% (5/31) and 22% (15/68), respectively. Sequencing the mtDNA cyt-b marker revealed two Plasmodium lineages, which had been previously described in different regions of the American continent, including a Neotropical region in Southeast Brazil, and one Haemoproteus lineage. The fact that avian malarial parasites have been found infecting the Black Skimmers in the Brazilian Amazon ecosystem, which exhibits considerable diversity, highlights the importance of these migratory birds as a potential source of infection and dispersion of pathogens to other susceptible birds of the Nearctic and Neotropical regions. PMID:26193823

  20. Prevalence and diversity of avian malaria parasites in migratory Black Skimmers (Rynchops niger, Laridae, Charadriiformes) from the Brazilian Amazon Basin.

    Science.gov (United States)

    Roos, F L; Belo, N O; Silveira, P; Braga, E M

    2015-10-01

    The Medium Solimões River region in the Brazilian Amazon Basin is an area utilized for reproduction and nesting by a variety of species of migratory aquatic birds such as Black Skimmers (Rynchops niger). These migratory birds form mixed-species reproductive colonies with high population densities and exhibit a large range of migration routes. This study aimed to describe the prevalence and diversity of the avian malaria parasites Plasmodium and Haemoproteus in Black Skimmers, on the basis of the association between microscopic observation of blood smears and amplification of the mitochondrial cytochrome b gene (mtDNA cyt-b). The overall prevalence rates of the parasites for juvenile and adult bird specimens were 16% (5/31) and 22% (15/68), respectively. Sequencing the mtDNA cyt-b marker revealed two Plasmodium lineages, which had been previously described in different regions of the American continent, including a Neotropical region in Southeast Brazil, and one Haemoproteus lineage. The fact that avian malarial parasites have been found infecting the Black Skimmers in the Brazilian Amazon ecosystem, which exhibits considerable diversity, highlights the importance of these migratory birds as a potential source of infection and dispersion of pathogens to other susceptible birds of the Nearctic and Neotropical regions.

  1. Outcomes of pregnancy among women living in the proximity of oil fields in the Amazon basin of Ecuador.

    Science.gov (United States)

    San Sebastián, Miguel; Armstrong, Ben; Stephens, Carolyn

    2002-01-01

    Oil companies have released billions of gallons of untreated wastes and oil directly into the environment of the Ecuadorian Amazon. This cross-sectional study investigated the environmental conditions and reproductive health of women living in rural communities surrounded by oil fields in the Amazon basin and in unexposed communities. Water from local streams was analyzed for total petroleum hydrocarbons (TPH). The women, aged 17 to 45 years, had resided for at least three years in the study communities. Socioeconomic and reproductive histories of the last three pregnancies were obtained from interviews. Information from the questionnaire was available for 365 exposed and 283 non-exposed women. The study was conducted from November 1998 to April 1999. Streams of exposed communities had TPH concentrations above the allowable limit. After adjustment for potential confounders, the pregnancies of women in exposed communities were more likely to end in spontaneous abortion (OR: 2.47; 95% CI: 1.61-3.79; p pollution in the area is needed.

  2. Influence of seasonality on the interaction of mercury with aquatic humic substances extracted from the Middle Negro River Basin (Amazon)

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Luciana C. de, E-mail: lcamargo@ufscar.br [Federal University of Sao Carlos (UFSCar), Sorocaba, SP (Brazil); Botero, Wander G. [Federal University of Alagoas (UFAL), Arapiraca, AL (Brazil); Santos, Felipe A. [Institute of Biosciences, Sao Paulo State University (UNESP), Botucatu, SP (Brazil); Sargentini Junior, Ezio [National Amazon Research Institute (INPA), Manaus, AM (Brazil); Rocha, Julio C.; Santos, Ademir dos [Institute of Chemistry of Araraquara, Sao Paulo State University (UNESP), Araraquara, SP (Brazil)

    2012-09-15

    High mercury concentrations in different environmental matrices in the Amazon have been attributed to mining activities. However, high concentrations of mercury are also present in the soil and water in places like in the middle of the Negro River Basin, which is far away from any anthropogenic emission sources. The Amazon region is characterized by two different regional seasons, with well-defined flood and low water periods. The objective of this work was to investigate the seasonal influences of the interaction between mercury and aquatic humic substances (AHS), which are the main agents of the natural organic complexation capacity. The results of the multivariate statistical analysis of the data showed that the humic substances had different structural characteristics, depending on each season. The ability of humic substances to form complexes with Hg(II) is not directly related to their carbon content, but to the nature and availability of the functional groups present in its structure. The functional groups are carboxylic and aromatic directly related to the higher complexation capacity of AHS by mercury ions. (author)

  3. Molecular differentiation of species of the genus Zungaro (Siluriformes, Pimelodidae) from the Amazon and Paraná-Paraguay River basins in Brazil.

    Science.gov (United States)

    Boni, T A; Padial, A A; Prioli, S M A P; Lucio, L C; Maniglia, T C; Bignotto, T S; Panarari-Antunes, R S; Prioli, R A; Prioli, A J

    2011-01-01

    Fish species of the Zungaro genus (Siluriformes, Pimelodidae) are amongst the largest migratory fish in Latin America and have considerable economic importance for commercial fishing in Brazil. However, natural populations of this large catfish are experiencing a severe decline. There are significant taxonomical inconsistencies for this fish. Two geographically separated species of the fish were initially described, one endemic in the Amazon and another in the Paraná-Paraguay River basins. A taxonomic review had recently proposed that there is only one Zungaro species in Brazil, based on morphological data. We made a molecular study of Zungaro populations in an attempt to solve taxonomical inconsistencies and to analyze genetic diversity in natural populations of this genus. We analyzed two regions of the mitochondrial DNA (the control region and the ATPase 6 gene region) of individuals sampled from the Paraná-Paraguay River and Amazon River basins. Analyses based on p-distances and maximum likelihood phylogenetic models showed a genetic difference between populations corresponding to different species. Genetic differentiation between Zungaro populations was at the same level as that observed between other Siluriformes species, using the same DNA sequences. We conclude that Zungaro species of the Paraná-Paraguay River basin do not belong to the same species found in the Amazon basin. This finding has a significant implication for conservation of this fish, given that populations are disappearing at a high rate in the Paraná-Paraguay River basin, mainly due to impoundments. PMID:22095604

  4. Delimiting Evolutionarily Significant Units of the Fish, Piaractus brachypomus (Characiformes: Serrasalmidae), from the Orinoco and Amazon River Basins with Insight on Routes of Historical Connectivity.

    Science.gov (United States)

    Escobar, Maria Doris; Andrade-López, Juana; Farias, Izeni P; Hrbek, Tomas

    2015-01-01

    The freshwater fish Piaractus brachypomus is an economically important for human consumption both in commercial fisheries and aquaculture in all South American countries where it occurs. In recent years the species has decreased in abundance due to heavy fishing pressure. The species occurs in the Amazon and Orinoco basins, but lack of meristic differences between fishes from the 2 basins, and extensive migration associated with reproduction, have resulted in P. brachypomus being considered a single panmictic species. Analysis of 7 nuclear microsatellites, mitochondrial DNA sequences (D-loop and COI), and body shape variables demonstrated that each river basin is populated by a distinct evolutionarily significant unit (ESU); the 2 groups had an average COI divergence of 3.5% and differed in body depth and relative head length. Historical connection between the 2 basins most probably occurred via the Rupununi portal rather than via the Casiquiare canal. The 2 ESUs will require independent fishery management, and translocation of fisheries stocks between basins should be avoided to prevent loss of local adaptations or extinction associated with outbreeding depression. Introductions of fishes from the Orinoco basin into the Putumayo River basin, an Amazon basin drainage, and evidence of hybridization between the 2 ESUs have already been detected.

  5. Delimiting Evolutionarily Significant Units of the Fish, Piaractus brachypomus (Characiformes: Serrasalmidae), from the Orinoco and Amazon River Basins with Insight on Routes of Historical Connectivity.

    Science.gov (United States)

    Escobar, Maria Doris; Andrade-López, Juana; Farias, Izeni P; Hrbek, Tomas

    2015-01-01

    The freshwater fish Piaractus brachypomus is an economically important for human consumption both in commercial fisheries and aquaculture in all South American countries where it occurs. In recent years the species has decreased in abundance due to heavy fishing pressure. The species occurs in the Amazon and Orinoco basins, but lack of meristic differences between fishes from the 2 basins, and extensive migration associated with reproduction, have resulted in P. brachypomus being considered a single panmictic species. Analysis of 7 nuclear microsatellites, mitochondrial DNA sequences (D-loop and COI), and body shape variables demonstrated that each river basin is populated by a distinct evolutionarily significant unit (ESU); the 2 groups had an average COI divergence of 3.5% and differed in body depth and relative head length. Historical connection between the 2 basins most probably occurred via the Rupununi portal rather than via the Casiquiare canal. The 2 ESUs will require independent fishery management, and translocation of fisheries stocks between basins should be avoided to prevent loss of local adaptations or extinction associated with outbreeding depression. Introductions of fishes from the Orinoco basin into the Putumayo River basin, an Amazon basin drainage, and evidence of hybridization between the 2 ESUs have already been detected. PMID:26245778

  6. Placentation in dolphins from the Amazon River Basin: the Boto, Inia geoffrensis, and the Tucuxi, Sotalia fluviatilis

    Directory of Open Access Journals (Sweden)

    Bonatelli Marina

    2007-06-01

    Full Text Available Abstract A recent reassessment of the phylogenetic affinities of cetaceans makes it timely to compare their placentation with that of the artiodactyls. We studied the placentae of two sympatric species of dolphin from the Amazon River Basin, representing two distinct families. The umbilical cord branched to supply a bilobed allantoic sac. Small blood vessels and smooth muscle bundles were found within the stroma of the cord. Foci of squamous metaplasia occurred in the allanto-amnion and allantochorion. The interhemal membrane of the placenta was of the epitheliochorial type. Two different types of trophoblastic epithelium were seen. Most was of the simple columnar type and indented by fetal capillaries. However, there were also areolar regions with tall columnar trophoblast and these were more sparsely supplied with capillaries. The endometrium was well vascularised and richly supplied with actively secreting glands. These findings are consistent with the current view that Cetacea are nested within Artiodactyla as sister group to the hippopotamids.

  7. Anatomy and systematics of Anodontites Elongatus (Swainson from Amazon and Parana Basins, Brazil (Mollusca, Bivalvia, Unionoida, Mycetopodidae

    Directory of Open Access Journals (Sweden)

    Luiz Ricardo L Simone

    1997-12-01

    Full Text Available The anatomy of Anodontiies elongatus (Swainson, 1823, a rare species restricted to the Amazon and Parana Basins, is described by first time, showing a group of conchological and anatomical characters exclusive of this species that may be analyzed to identify it. Diagnosis of A. elongatus: shell long antero-posteriorly, umbones prominent, periostracum opaque and smooth, two posterior radial striae; middle fold of mantle edge veiy tall; gill long antero-posteriorly and short dorso-ventrally, extending about a half of it total length beyond visceral mass; palps proportionally small, several furrows in its outer surface; stomach without esophageal transversal ridjp, dorsal hood and gastric shield poorly developed, major typhlosole entering in ddd , posterior pouch of sa³ very-long; style sac reduced, without crystalline style; distal region of intestine and rectum with a well developed typhlosole, "T" in section, other intestinal regions without folds; gonad gonochoristic.

  8. Evaluation of drought indices at interannual to climate change timescales: a case study over the Amazon and Mississippi river basins

    Directory of Open Access Journals (Sweden)

    E. Joetzjer

    2012-11-01

    Full Text Available The present study compares three meteorological drought indices (scPDSI, SPI and SPEI respectively and their ability to account for the variations of annual mean river discharge on both interannual and climate change timescales. The Standardized Runoff Index (SRI is used as a proxy of river discharge. The Mississippi and Amazon river basins provide two contrasted testbeds for this analysis. All meteorological drought indices are derived from monthly 2-meter temperature and/or precipitation, using either gridded observations or outputs of a global climate model. The SPI based solely on precipitation is not outperformed by the SPEI (accounting for potential evapotranspiration and the scPDSI (based on a simplified water balance at detecting interannual SRI variations. Under increasing concentrations of greenhouse gases, the simulated response of the areal fraction in drought is highly index-dependent, suggesting that more physical water balance models are needed to account for the impact of global warming on hydrological droughts.

  9. An initial examination of the epidemiology of malaria in the State of Roraima, in the Brazilian Amazon Basin

    Directory of Open Access Journals (Sweden)

    CHAVES Sandra S.

    2000-01-01

    Full Text Available This study firstly describes the epidemiology of malaria in Roraima, Amazon Basin in Brazil, in the years from 1991 to 1993: the predominance of plasmodium species, distribution of the blood slides examined, the malaria risk and seasonality; and secondly investigates whether population growth from 1962 to 1993 was associated with increasing risk of malaria. Frequency of malaria varied significantly by municipality. Marginally more malaria cases were reported during the dry season (from October to April, even after controlling for by year and municipality. Vivax was the predominant type in all municipalities but the ratio of plasmodium types varied between municipalities. No direct association between population growth and increasing risk of malaria from 1962 to 1993 was detected. Malaria in Roraima is of the "frontier" epidemiological type with high epidemic potential.

  10. Two new species of Euptychia Hübner, 1818 from the upper Amazon basin (Lepidoptera, Nymphalidae, Satyrinae).

    Science.gov (United States)

    Neild, Andrew F E; Nakahara, Shinichi; Zacca, Thamara; Fratello, Steven; Lamas, Gerardo; Le Crom, Jean-François; Dolibaina, Diego R; Dias, Fernando M S; Casagrande, Mirna M; Mielke, Olaf H H; Espeland, Marianne

    2015-01-01

    Two new species of Euptychia Hübner, 1818 are described from the upper Amazon basin: Euptychia attenboroughi Neild, Nakahara, Fratello & Le Crom, sp. n. (type locality: Amazonas, Venezuela), and Euptychia sophiae Zacca, Nakahara, Dolibaina & Dias, sp. n. (type locality: Acre, Brazil). Their unusual facies prompted molecular and phylogenetic analyses of one of the species resulting in support for their classification in monophyletic Euptychia. Diagnostic characters for the two species are presented based on wing morphology, wing pattern, presence of androconial patches on the hindwing, and genitalia. Our results indicate that the projection of the tegumen above the uncus, previously considered a synapomorphy for Euptychia, is not shared by all species in the genus. The adults and their genitalia are documented, and distribution data and a map are provided.

  11. Past terrestrial water storage (1980–2008 in the Amazon Basin reconstructed from GRACE and in situ river gauging data

    Directory of Open Access Journals (Sweden)

    M. Becker

    2011-02-01

    Full Text Available Terrestrial water storage (TWS composed of surface waters, soil moisture, groundwater and snow where appropriate, is a key element of global and continental water cycle. Since 2002, the Gravity Recovery and Climate Experiment (GRACE space gravimetry mission provides a new tool to measure large-scale TWS variations. However, for the past few decades, direct estimate of TWS variability is accessible from hydrological modeling only. Here we propose a novel approach that combines GRACE-based TWS spatial patterns with multi-decadal-long in situ river level records, to reconstruct past 2-D TWS over a river basin. Results are presented for the Amazon Basin for the period 1980–2008, focusing on the interannual time scale. Results are compared with past TWS estimated by the global hydrological model ISBA-TRIP. Correlations between reconstructed past interannual TWS variability and known climate forcing modes over the region (e.g., El Niño-Southern Oscillation and Pacific Decadal Oscillation are also estimated. This method offers new perspective for improving our knowledge of past interannual TWS in world river basins where natural climate variability (as opposed to direct anthropogenic forcing drives TWS variations.

  12. Environmental hazard of pesticides applied in the border region between Platinum and Amazon Basins at the turn to century XXI

    Directory of Open Access Journals (Sweden)

    Arno Rieder

    2012-03-01

    Full Text Available Objective: To reveal the environmental risk of pesticide prescribed in a border region between the Amazon and Platinum Basins, at the turn of the 21st century. Methods: The study used data of agronomic prescriptions for pesticides issued in the biennium of 1999-2000 in 24 cities located in a border region between the Amazon and Platinum Basins, Mato Grosso, Brazil. Results: The most widely used pesticides in the study region are class II (very dangerous and III (dangerous in number of prescriptions (N = 2,828, 86.8% andquantity prescribed (N = 344,765, 90.4%. Among class III pesticides, a strong inversion was observed in the number of prescriptions (N = 1,274; 39.1% and quantity prescribed (N = 237,319; 62.2%, indicating a lower number of prescriptions, but with higher amountprescribed. The proportion of prescriptions for products amid the various classes of Potential of Environmental Dangers (PPA ranking model, apllied in Brazil changed over the two years (c2=20,814; DF=3; p < 0,01. The 10 most prescribed products (11 activecompounds were: glyphosate, 2,4-D, sulfluramid, chlorimuron ethyl, fipronil, diuron, paraquat, methamidophos, carbofuran, chlorpyrifos and lambda-cyhalothrin, and seven of them were ranked as PPA class I or II. Conclusions: The ratio between the number of pesticide prescriptions and the quantities prescribed among the various classes of PPA showed alteration over crop years. The most reported products in this border region were classified as the most dangerous ones, with diverse mechanisms of action and potential risksto living organisms. This suggests the need to define specific policies and carefully designed strategies to prevent environmental disaster in this region.

  13. A Conceptual model of Ecophysiological Function across the Amazon Basin using a Synthesis of Observed and Model Data.

    Science.gov (United States)

    Baker, I. T.; Denning, A. S.; Harper, A. B.

    2008-12-01

    Observations of the seasonal cycle of Net Ecosystem Exchange of Carbon (NEE) are variable across the Amazon Basin. NEE has been observed to be nearly uniform through the year at sites such as Cueiras Reserve in Amazonas. A pattern of efflux during the wet season and uptake during seasonal drought has been observed at multiple sites in the Tapajos River National Forest, while the opposite pattern (uptake during wet season, efflux during seasonal drought) has been observed at several sites in Mato Grosso . Using a synthesis of eddy covariance flux observations from multiple sites across vegetation and moisture gradients in the Amazon basin and a biophysical model (Simple Biosphere Model, SiB), we construct a conceptual model of the patterns of ecophysiological function that determine annual cycles and interannual variability in observed NEE across tropical Amazonia. We identify several factors that determine the behavior of Gross Primary Productivity (GPP) and respiration fluxes, while NEE is determined by their sum. We evaluate our conceptual model across a pseudo-latitudinal gradient from extremely wet (more than 2000 mm annual precipitation) in the north to drier cerrado (savanna) regions in the south. In the extremely wet regions near the equator we find little or no stress on photosynthesis and, subsequently, little or no variability in annual cycles of energy or carbon flux. In these regions NEE is determined by vegetation response to high-frequency meteorological events. As precipitation decreases, the flux seasonality increases and phase relationships between GPP and respiration determine annual NEE cycles. As GPP/respiration cycles transition from an out-of-phase relationship in wetter regions to an in-phase pattern in the cerrado, NEE changes from dry to wet season carbon uptake.

  14. Deforestation fires versus understory fires in the Amazon Basin: What can we learn from satellite-based CO measurements?

    Science.gov (United States)

    Martinez-Alonso, S.; Deeter, M. N.; Worden, H. M.; Gille, J. C.; Clerbaux, C.; George, M.

    2014-12-01

    Deforestation fires in the Amazon Basin abound during the dry season (July to October) and are mostly associated with "slash and burn" agricultural practices. Understory fires occur when fires escape from deforested areas into neighboring standing forests; they spread slowly below the canopy, affecting areas that may be comparable or even larger than clear-cut areas. The interannual variabilities of understory fires and deforestation rates appear to be uncorrelated. Areas burned in understory fires are particularly extensive during droughts. Because they progress below a canopy of living trees, understory fires and their effects are not as easily identifiable from space as deforestation fires. Here we analyze satellite remote sensing products for CO and fire to investigate differences between deforestation fires and understory fires in the Amazon Basin under varying climatic conditions. The MOPITT (Measurements Of Pollution In The Troposphere) instrument on board NASA's Terra satellite has been measuring tropospheric CO since 2000, providing the longest global CO record to date. IASI (the Infrared Atmospheric Sounding Interferometer) A and B are two instruments on board METOP-A and -B, respectively, measuring, among others, CO since 2006 and 2012. MODIS (the Moderate Resolution Imaging Spectroradiometer) instruments on board NASA's Terra and Aqua satellites provide, among other products, a daily record of fires and their effects since 2000 and 2002, respectively. The temporal extent of all these datasets allows for the detailed analysis of drought versus non-drought years. Initial results indicate that MOPITT CO emissions during the dry season peaked in 2005, 2007, and 2010. Those were draught years and coincide with peaks in area affected by understory fires.

  15. Offspring production in three freshwater crab species (Brachyura: Pseudothelphusidae from the Amazon region and Central America

    Directory of Open Access Journals (Sweden)

    Ingo S. Wehrtmann

    2010-01-01

    Full Text Available Freshwater crabs are an important component of the fauna of limnic environments, and out of the two true freshwater crab families present in the Neotropics, Pseudothelphusidae is the most diverse. Considering the lack of information regarding reproductive features of neotropical freshwater crabs, we studied, for the first time, the fecundity and the presence of juveniles carried by females of two pseudothelphusids from the Amazon region - Kingsleya latifrons (Randall, 1840 and Kingsleya ytupora Magalhães, 1986 - and one from Central America - Potamocarcinus magnus (Rathbun, 1896. The two Kingsleya species produced relatively few (56-114 and large eggs (1.9-3.7 mm, typical for species with an abbreviated or direct development. Recently produced eggs were substantially larger in K. latifrons (mean 2.83 mm when compared to those of K. ytupora (mean 1.87 mm; however, at the end of the embryogenesis, mean egg diameter was similar in both species. Therefore, it is assumed that hatchlings in both species should have a similar size. A brief description of attached juveniles of K. ytupora is provided. The number of juveniles varied between 30 (K. ytupora and 179 (P. magnus; two size groups of juveniles were found, which indicates that the offspring cling to their mother for a prolonged period of time. There was no significant loss of eggs and juveniles; it is assumed that parental care diminishes the loss of their offspring. We compiled the available information of reproductive aspects from freshwater crabs: egg diameter was in the range of 2-3 mm, independent of female size and fecundity, and reported egg number varied between 9 and 417 eggs.

  16. Xiphidorus amazonensis n. sp. (Nematoda: Longidoridae) from the Brazilian Amazon Basin.

    Science.gov (United States)

    Uesugi, C H; Huang, C S; Cares, J E

    1985-07-01

    Xiphidorus amazonensis n. sp. was found in the rhizospheres of Jatropha curcas, Musa sp., Anona muricata, Cassia tora, Panicum laxum, Paspalum fasciculatum, Aeschynomene sensitiva, Saccharum officinarum, Manihot esculenta, Abelmoschus esculentus, Tamarindus indica, Mangifera indica, Vigna unguiculata, Zea mays, Commelina sp., Cyperus rotundus, Fimbristylis miliacea, Citrus sinensis, and Eichhornia crassipes on the Amazon River island of Xiborena, approximately 40 km southeast of Manaus, capital of the State of Amazonas. The type habitat is flooded annually for about 6 months by the Amazon River. Xiphidorus amazonensis n. sp. differs from the closely related species Xiphidorus yepesara Monteiro, 1976 by the larger size, by a, b, and c values, and by the rounded tail terminus. It also resembles Xiphidorus tucumanensis Chaves and Coomans, 1984, but can be distinguished by its larger size, larger a, b, and c values, more conical female tail, bilobed amphidial pouch, and the presence of a spermatheca full of sperm. PMID:19294098

  17. Model for the isotopic fractionation of water in the Amazon basin

    International Nuclear Information System (INIS)

    Two models on the isotopic fractionation of water are presented. In the first model. It is assumed that the only source of water vapour for the Amazon region is the Atlantic Ocean, introduced by the predominant easterly winds. The second model contains the assumption that the forest also serves as a source of water vapour contributing an equal volume of water to the regional rains as the vapour of oceanic origin. (Author)

  18. U-Pbdating on detrital zircon and Nd and Hf isotopes related to the provenance of siliciclastic rocks of the Amazon Basin: Implications for the origin of Proto-Amazonas River

    Science.gov (United States)

    Dantas, Elton Luiz; Silva Souza, Valmir; Nogueira, Afonso C. R.; Ventura Santos, Roberto; Poitrasson, Franck; Vieira Cruz, Lucieth; Mendes Conceição, Anderson

    2014-05-01

    Previous provenance studies along the Amazonas river have demonstrated that the Amazon drainage basin has been reorganized since the Late Cretaceous with the uplift of the Andes and the establishment of the transcontinental Amazon fluvial system from Late Miocene to Late Pleistocene (Hoorn et al., 1995; Potter, 1997, Wesselingh et al., 2002; Figueiredo et al. 2009, Campbell et al., 2006, Nogueira et al. 2013).There is a lack of data from Eastern and Central Amazonia and only limited core data from the Continental Platform near to current Amazonas river mouth. Central Amazonia is strategic to unveil the origin of Amazonas River because it represents the region where the connection of the Solimões and Amazonas basin can be studied through time (Nogueira et al. 2013). Also, there is a shortage of information on the old Precambrian and Paleozoic sediment sources relative to Cretaceous and Miocene siliciclastic deposits of the Solimões and Amazonas basins. We collected stratigraphic data, detrital zircon U-Pb ages and Nd and Hf isotopes from Precambrian, Paleozoic, Cretaceous and Miocene siliciclastic deposits of the Northwestern border of Amazonas Basin. They are exposed in the Presidente Figueiredo region and in the scarps of Amazon River, and occur to the east of the Purus Arch. This Northwest-Southeast trending structural feature that divides the Solimões and Amazonas basin was active at various times since the Paleozoic. Detrital zircon ages for the Neoproterozoic Prosperança Formation yielded a complex signature, with different populations of Neoproterozoic (550, 630 and 800 Ma) and Paleoproterozoic to Archean sources (1.6, 2.1 and 2.6 Ga). Also Nd and Hf isotopes show two groups of TDM model ages between 1.4 to 1.53 Ga and 2.2 and 3.1 Ga. Sediments typical of Paleozoic sedimentary rocks of the Nhamundá and Manacapuru Formations revealed NdTDM model ages of 1.7, 2.2 and 2.7 Ga, but Hf isotopes and U-Pb zircon ages are more varied. They characterize a

  19. Linking carbon storage with functional diversity in tropical rainforest in the central Congo Basin

    Science.gov (United States)

    Verbeeck, Hans; Kearsley, Elizabeth; Bauters, Marijn; Beeckman, Hans; Huygens, Dries; Steppe, Kathy; Boeckx, Pascal

    2015-04-01

    This presentation will show an overview of results of the COBIMFO project (Congo basin integrated monitoring for forest carbon mitigation and biodiversity). In the framework of this project we have established 21 permanent 1 ha sampling plots in different forest types in the Yangambi reserve. This UNESCO Man and Biosphere reserve has an area of more than 6000 km² and is located in the heart of the Congo Basin near the Yangambi research station (DR Congo). Analysis of the inventory data of these plots revealed that carbon stocks in mature forests in this area of the Congo Basin are significantly lower (24%) than stocks recorded in the outer regions of the basin. These lower stocks are attributed to a lower maximal tree height (Kearsley et al. 2013). In addition to the carbon inventories we collected leaf and wood samples on all species within 95% basal area of each of the Yangambi plots. A total of 995 individuals were sampled, covering 123 tree species. On the samples we measured 15 traits related to leaf and wood morphology and functioning. In the presented study, relationships between the observed functional diversity and biomass are analysed. One of the remarkable results of our analysis is that species with a high functional distinctiveness have a low contribution to the basal area and the carbon stocks. In contrast, species with a high contribution to the carbon stock have a low contribution to the functional diversity. Similar patterns have been observed elsewhere (e.g. Amazon basin), but are now for the first time confirmed for central African rainforest. Finally, we also present the first results of an analysis of carbons stocks and functional diversity in tropical plantations from a unique 70-years old tree diversity experiment that was established during the colonial period at the Yangambi research station. Kearsley, E., de Haulleville, T., Hufkens, K., Kidimbu, A., Toirambe, B., Baert, G., Huygens, D., Kebede, Y., Defourny, P., Bogaert, J., Beeckman, H

  20. Impacts of climate variability and extreme events on the terrestrial carbon cycle of the Amazon basin

    Science.gov (United States)

    Harper, A. B.; Cox, P.; Wiltshire, A.; Friedlingstein, P.; Jones, C. D.; Mercado, L.; Groenendijk, M.; Sitch, S.

    2013-12-01

    Several climate models predict reduced dry season rainfall in the Amazon region as a consequence of climate change. Drier dry seasons could have profound negative consequences for the forest, since soil moisture levels are already near their lower limit during this time of the year. Two recent dry season droughts (during 2005 and 2010) could provide insight into the future of the region. These droughts were associated with sea surface temperature anomalies in the tropical North Atlantic Ocean. Additionally, El Niño-related temperature anomalies in the tropical Pacific Ocean can lead to drought in the northern Amazon. In this work, we use a land surface model with updated physiology and vegetation dynamics to investigate responses of the Amazon terrestrial carbon cycle to recent droughts. JULES (the Joint UK Land-Environment Simulator) is the land surface model in the Hadley Centre Earth System Model. Several recent model developments have improved its ability to replicate seasonal cycles of land fluxes in tropical forests, such as new plant functional types, plant trait-based physiological parameters, and a multi-layer canopy with two-stream radiation and sunfleck penetration. In addition, several non-standard updates to JULES can improve the model in this region: including a representation of deeper soils and efficient roots, and parameter optimization. The soil and rooting adjustments are based on previous work with the Simple Biosphere (SiB3) model, which has been tested extensively in the Amazon. SiB3 can include a climate-derived, spatially varying predictor of forest drought resistance, which enabled it to simulate forest response to persistent soil moisture deficits during two rainfall exclusion projects in the Amazon. We ran JULES from pre-industrial to present day, forced with observed climate, atmospheric CO2, and land use. A mixture of satellite- and ground-based observations was used to validate JULES seasonal cycles of surface fluxes, phenology

  1. Penicillium excelsum sp. nov from the Brazil Nut Tree Ecosystem in the Amazon Basin'.

    Science.gov (United States)

    Taniwaki, Marta Hiromi; Pitt, John I; Iamanaka, Beatriz T; Massi, Fernanda P; Fungaro, Maria Helena P; Frisvad, Jens C

    2015-01-01

    A new Penicillium species, P. excelsum, is described here using morphological characters, extrolite and partial sequence data from the ITS, β-tubulin and calmodulin genes. It was isolated repeatedly using samples of nut shells and flowers from the brazil nut tree, Bertolletia excelsa, as well as bees and ants from the tree ecosystem in the Amazon rainforest. The species produces andrastin A, curvulic acid, penicillic acid and xanthoepocin, and has unique partial β-tubulin and calmodulin gene sequences. The holotype of P. excelsum is CCT 7772, while ITAL 7572 and IBT 31516 are cultures derived from the holotype.

  2. Bioaccumulation of methylmercury in fish tissue from the Roosevelt River, Southwestern Amazon basin

    OpenAIRE

    Marcelo Rodrigues dos Anjos; Nadja Gomes Machado; Maria Eliana Peixoto da Silva; Wanderley Rodrigues Bastos; Márcio Rodrigues Miranda; Dario Pires Carvalho; Marília Higino Mussy; Igor Bruno Barbosa de Holanda; Marcelo Sacardi Biudes; João Ânderson Fulan

    2016-01-01

    Mercury is a major pollutant in the Amazon River system, and its levels in fish and human hair are usually above the limit recommended by health agencies. The objective of this study was to analyze the methylmercury (MeHg) concentration in fish tissue from the Roosevelt River. The river's water velocity, depth, pH, temperature, electrical conductivity, dissolved oxygen and substrate type were measured, and fifty specimens distributed in 14 fish species were collected. A total of 64.3% of the ...

  3. Study of the anabranch dynamics for different sinuosity stages in the Upper Amazon River Basin

    Science.gov (United States)

    Frias, C. E.; Mendoza, A.; Dauer, K.; Abad, J. D.; Montoro, H.; Paredes, J.; Vizcarra, J.

    2013-12-01

    The Upper Peruvian Amazon River is characterized by a sequence of anabranching structures, which are composed by several channels behaving as non-developed and quasy-freely meandering channels. The widest channel in these anabranching structures is considered as the main channel or main anabranch while the other channels are secondary anabranches. Based on satellite imagery, it is observed that the main channels show different sinuosities along the Upper Peruvian Amazon River valley. Little is known about the effects of the planform characteristics of the main channel into the morphodynamics of the secondary anabranches. Thus, two study sites were selected to characterize anabranching structures with low and medium-high sinuosity main channels. For the low sinuosity main channel case, an area at the tri-point boundary between Colombia-Brazil and Peru was selected. For the medium-high sinuosity main channel case, an area upstream of Iquitos City (the largest city in the Peruvian Amazon Rainforest) was selected. A field campaign was carried out on 2010 and 2011 for the medium-high and low sinuosity stages respectively. On this field campaign velocity measurement, bathymetry and water surface elevations were obtained. With the field data it was possible to develop and validate a two dimensional shallow water numerical model to study the hydrodynamics on both sites. This allows us to discuss the effects of the current planform configuration of the anabranching structures into the short-term behavior of individual channels. In past studies, temporal analysis of the Amazon River planform have been carried out using satellite imagery with special focus into the floodplain, main channel, number of islands and valley slope. However, the dynamics in these anabranching structures containing multiple channels have not been studied in detailed. The metrics obtained for this study were sinuosity, channel width and annual migration rates. It was confirmed that in a medium to high

  4. Delaware basin/Central basin platform margin: The development of a subthrust deep-gas province in the Permian Basin

    Energy Technology Data Exchange (ETDEWEB)

    Purves, W.J. (Mobil Oil Corp., Midland, TX (USA)); Ting, S.C. (Mobil, Farmers Branch, TX (USA))

    1990-05-01

    A deep-gas-prone province was identified along the Delaware basin/Central Basin platform margin, a margin conventionally interpreted to be bounded by high-angle normal or high-angle reverse structures. Redefinition of the tectonic style between the Delaware basin and the adjacent platform resulted in the identification of this Delaware basin/Central Basin platform subthrust province and a giant prospect within it. Definition of a giant-sized gas prospect in northern Pecos County, Texas, revealed that portions of this margin may be characterized by shingled, low-angle, eastward-dipping, basement involved thrust faults. Interpretations suggest that hidden, subthrust footwall structures may trend discontinuously for greater than 100 mi along this structural margin. Subthrust footwall structures formed as basinal buttress points for the Central Basin platform to climb over the Delaware basin. In this area, structural relief of over 19,000 ft over a 10-mi width is believed due to stacking of low-angle thrust sheets. Seismic resolution of this subthrust margin has been complexed by allochtonous hanging-wall gravity-glide blocks and folds and by velocity changes in overlying syn- and posttectonic sediments associated with basin-to-shelf lithofacies changes. Statistical studies indicate that this deep-gas province has a play potential of greater than 10 tcf of gas, with individual prospect sizes exceeding 1 tcfg. The prospects defined along this trend are deep (approximately 20,000 ft) subthrust structural traps that are indigenously sourced and reservoired by dual-matrix porosity. Vitrinite supported maturation modeling suggests that these subthrust structures formed prior to catagenic conversion of the oldest source rocks to oil and later to gas. Tectonically fractured Ordovician Ellenburger and Devonian sediments are considered the principal reservoirs. Shales overlying reservoir intervals form vertical seals.

  5. The optical properties of river and floodplain waters in the Amazon River Basin : implications for satellite-based measurements of suspended particulate matter

    OpenAIRE

    Martinez, Jean-Michel; Espinoza-Villar, R.; Armijos, E.; Moreira, L.S.

    2015-01-01

    Satellite images can now be used to assess river sediment discharge, and systematic studies over rivers and lakes are required to support such applications and document the variability of inland water optical properties at the watershed scale. The optical properties of the Amazon Basin waters were analyzed from in situ measurements of the remote sensing reflectance (R-rs) at 279 stations and downwelling diffuse attenuation coefficients (K-d) at 133 stations. Measurements of the apparent optic...

  6. Recent history of the agriculture of the Brazilian Amazon Basin : prospects for sustainable development and a first look at the biogeochemical consequences of pasture reformation

    OpenAIRE

    Cerri, C. C.,; Melillo, J M; Feigl, B. J.,; Piccolo, M.C.; Neill, C.; Steuder, P.A.; Carvalho, M. da C.S.; Godinho, V.P.; Cerri, C. E. P.,; Bernoux, Martial

    2005-01-01

    Land-use change for human settlement and agricultural purposes, especially pasture establishment, has caused major impacts on the Amazon Basin's environment. Development of strategies for reformation and restoration of already degraded pastures constitutes the main goal of the authors' research work. For some of this work, a homogeneous area of land in terms of soil characteristics was selected at Nova Vida ranch in Rondônia state to conduct a multidisciplinary experiment, w...

  7. Tracking water level changes of the Amazon Basin with space-borne remote sensing and integration with large scale hydrodynamic modelling: A review

    Science.gov (United States)

    Hall, Amanda C.; Schumann, Guy J.-P.; Bamber, Jonathan L.; Bates, Paul D.

    2011-01-01

    With the improvement of remote sensing systems, in particular active sensors, our ability to make regular observations of the Amazon Basin has greatly increased. Water levels and other related features such as discharge, floodplain-river connectivity, and flood extent are now being monitored using space-borne sensors, thereby complimenting in situ gauging networks. This review concludes that the main advances remote sensing has had on our knowledge of hydrology includes the ability observe the seasonal cycles of the Amazon River across the entire basin, including the movement of the flood wave downstream. Flood extent can now be mapped, including the direction of floodplain flow, thanks to the extensive coverage provided by various active remote sensing systems. Our knowledge of the relationship between water levels in the main channel and the floodplain has been reassessed. It is now known that floodplain levels are related to the distance of the location from the main channel. The addition of new and future satellites, such as ICESat-1 and -2, GRACE and SWOT, will guarantee the continuation of research in this field and the continued advancement of knowledge and understanding of the Amazon Basin.

  8. Characteristics and Diurnal Cycle of GPM Rainfall Estimates over the Central Amazon Region

    Directory of Open Access Journals (Sweden)

    Rômulo Oliveira

    2016-06-01

    Full Text Available Studies that investigate and evaluate the quality, limitations and uncertainties of satellite rainfall estimates are fundamental to assure the correct and successful use of these products in applications, such as climate studies, hydrological modeling and natural hazard monitoring. Over regions of the globe that lack in situ observations, such studies are only possible through intensive field measurement campaigns, which provide a range of high quality ground measurements, e.g., CHUVA (Cloud processes of tHe main precipitation systems in Brazil: A contribUtion to cloud resolVing modeling and to the GlobAl Precipitation Measurement and GoAmazon (Observations and Modeling of the Green Ocean Amazon over the Brazilian Amazon during 2014/2015. This study aims to assess the characteristics of Global Precipitation Measurement (GPM satellite-based precipitation estimates in representing the diurnal cycle over the Brazilian Amazon. The Integrated Multi-satellitE Retrievals for Global Precipitation Measurement (IMERG and the Goddard Profiling Algorithm—Version 2014 (GPROF2014 algorithms are evaluated against ground-based radar observations. Specifically, the S-band weather radar from the Amazon Protection National System (SIPAM, is first validated against the X-band CHUVA radar and then used as a reference to evaluate GPM precipitation. Results showed satisfactory agreement between S-band SIPAM radar and both IMERG and GPROF2014 algorithms. However, during the wet season, IMERG, which uses the GPROF2014 rainfall retrieval from the GPM Microwave Imager (GMI sensor, significantly overestimates the frequency of heavy rainfall volumes around 00:00–04:00 UTC and 15:00–18:00 UTC. This overestimation is particularly evident over the Negro, Solimões and Amazon rivers due to the poorly-calibrated algorithm over water surfaces. On the other hand, during the dry season, the IMERG product underestimates mean precipitation in comparison to the S-band SIPAM

  9. Evolutionary model of the oblique rift basins- Central African Rifts

    Science.gov (United States)

    Yang, Kenn-Ming; Cheng, I.-Wen; Wu, Jong-Chang

    2016-04-01

    The geometry of oblique-rifting basin is strongly related with the angle (α) between the trend of rift and that of regional major extensional stress. The main purpose of this study is to investigate characteristics of geometry and kinematics of structure and tectono-stratigraphy during basin evolution of Central African Rifts (CAS). In this study, we simulated the formation of oblique-rifting basin with Particle Flow Code 3-Dimensions-(PFC 3D) and compared the simulation results with the tectonic settings of a series of basin in CAS. CAS started to develop in Early Cretaceous (130Ma) and lasted until the Late Cretaceous (85Ma-80Ma). The following collision between the African and Eurasian plates imposed compressional stress on CAS and folded the strata in the rift basins. Although the characteristics of rift basin formation remain controversial, palinspastic sections constructed in this study show that, in the Early Cretaceous, the rift basins are mainly characterized by normal faults and half-grabens. In the Late Cretaceous, the morphology of the rift basins was altered by large-scaled tectonic compression with the active Borogop Fault of regional scale. Also, en echelon trend of normal faults in the basins were measured and the angles between the trend with that of the rift axes of each basin were demonstrated, indicating that the development of CAS was affected by the regional extensional stress with a dextral component during the rifting process and, therefore, the rift basins were formed by oblique-rifting. In this study, we simulated the oblique-rifting basin model of various α with Particle Flow Code 3-Dimensions-(PFC 3D). The main theory of PFC 3D is based on the Discrete Element Method (DEM), in which parameters are applied to every particle in the models. We applied forces acting on both sides of rift axis, which α are 45°, 60°, 75° and 90° respectively, to simulate basin formation under oblique-rifting process. The study results of simulation

  10. Towards SWOT data assimilation for hydrology : automatic calibration of global flow routing model parameters in the Amazon basin

    Science.gov (United States)

    Mouffe, M.; Getirana, A.; Ricci, S. M.; Lion, C.; Biancamaria, S.; Boone, A.; Mognard, N. M.; Rogel, P.

    2011-12-01

    The Surface Water and Ocean Topography (SWOT) mission is a swath mapping radar interferometer that will provide global measurements of water surface elevation (WSE). The revisit time depends upon latitude and varies from two (low latitudes) to ten (high latitudes) per 22-day orbit repeat period. The high resolution and the global coverage of the SWOT data open the way for new hydrology studies. Here, the aim is to investigate the use of virtually generated SWOT data to improve discharge simulation using data assimilation techniques. In the framework of the SWOT virtual mission (VM), this study presents the first results of the automatic calibration of a global flow routing (GFR) scheme using SWOT VM measurements for the Amazon basin. The Hydrological Modeling and Analysis Platform (HyMAP) is used along with the MOCOM-UA multi-criteria global optimization algorithm. HyMAP has a 0.25-degree spatial resolution and runs at the daily time step to simulate discharge, water levels and floodplains. The surface runoff and baseflow drainage derived from the Interactions Sol-Biosphère-Atmosphère (ISBA) model are used as inputs for HyMAP. Previous works showed that the use of ENVISAT data enables the reduction of the uncertainty on some of the hydrological model parameters, such as river width and depth, Manning roughness coefficient and groundwater time delay. In the framework of the SWOT preparation work, the automatic calibration procedure was applied using SWOT VM measurements. For this Observing System Experiment (OSE), the synthetical data were obtained applying an instrument simulator (representing realistic SWOT errors) for one hydrological year to HYMAP simulated WSE using a "true" set of parameters. Only pixels representing rivers larger than 100 meters within the Amazon basin are considered to produce SWOT VM measurements. The automatic calibration procedure leads to the estimation of optimal parametersminimizing objective functions that formulate the difference

  11. Salt movements within the Central European basin system

    Energy Technology Data Exchange (ETDEWEB)

    Maystrenko, Yuriy; Bayer, Ulf; Scheck-Wenderoth [GeoForschungsZentrum (GFZ), Potsdam (Germany); Littke, Ralf [RWTH Aachen (Germany). Lehrstuhl fuer Geologie, Geochemie und Lagerstaetten des Erdoels und der Kohle

    2010-04-15

    Evolution of salt structures in relation to tectonic events within central part of the Central European Basin System is described by summarizing results which have been obtained and published in frame of the research project DFG-SPP 1135. These results illustrate main phases of salt tectonics within the basin system from the Triassic to present day. During the Buntsandstein and Muschelkalk, extension triggered raft tectonics and salt movements within the Ems Trough, the Glueckstadt and the Horn Grabens. The next phase of salt movements occurred in response to a Middle-Late Keuper regional extensional event which was strongest within the Triassic depocenters of the Central European Basin System, such as the Horn Graben, the Glueckstadt Graben, the Ems and the Rheinsberg Troughs. Regional erosion truncated the study area during the Late Jurassic-Early Cretaceous time. The magnitude of Late Jurassic-Early Cretaceous erosion is declining towards southern margin of the basin system where a dextral transtensional regime was established in the Lower Saxony Basin and neighboring areas during the Late Jurassic-Early Cretaceous. The late Early Cretaceous-early Late Cretaceous is characterized by a relative tectonic quiescence without strong salt movements. The Late Cretaceous-Early Cenozoic inversion provocated renewed salt movements, causing the thick-skinned salt tectonics along the Elbe Fault System and the thin-skinned character of salt movements towards the north from the area of strain localisation. Post-inversion Cenozoic subsidence was accompanied by salt movements, related either to diapiric rise due to regional shortening and/or to local almost E-W directed extension. (orig.)

  12. Land-Use Change, Soil Process and Trace Gas Fluxes in the Brazilian Amazon Basin

    Science.gov (United States)

    Melillo, Jerry M.; Steudler, Paul A.

    1997-01-01

    We measured changes in key soil processes and the fluxes of CO2, CH4 and N2O associated with the conversion of tropical rainforest to pasture in Rondonia, a state in the southwest Amazon that has experienced rapid deforestation, primarily for cattle ranching, since the late 1970s. These measurements provide a comprehensive quantitative picture of the nature of surface soil element stocks, C and nutrient dynamics, and trace gas fluxes between soils and the atmosphere during the entire sequence of land-use change from the initial cutting and burning of native forest, through planting and establishment of pasture grass and ending with very old continuously-pastured land. All of our work is done in cooperation with Brazilian scientists at the Centro de Energia Nuclear na Agricultura (CENA) through an extant official bi-lateral agreement between the Marine Biological Laboratory and the University of Sao Paulo, CENA's parent institution.

  13. Seismic stratigraphic framework of deep central Gulf of Mexico basin

    Energy Technology Data Exchange (ETDEWEB)

    Shaub, F.J.; Buffler, R.T.; Parsons, J.G.

    1984-11-01

    The deep Gulf of Mexico basin is underlain by up to 10 km (33,000 ft) of Jurassic(.) to Holocene layered sedimentary rocks. The multichannel reflection seismic record from the deep Gulf of Mexico was divided into six seismic stratigraphic units for study of the geologic history of this accumulation. The basal Challenger unit (Jurassic (.) to middle Cretaceous) is considered coeval with early basin formation. We interpret it as a deep marine sequence overlying oceanic crust in the central basin and as continental and shallow through deep marine rocks, including thick evaporites, over adjacent transitional crust. The next three units, Campeche, Lower Mexican Ridges and Upper Mexican Ridges, indicate that from the Late Cretaceous through middle Miocene the basin filled progressively from the west and north, most probably with siliceous turbidites interlayered with pelagic deposits. By the late Tertiary, however, salt and shale deformation within thick sedimentary sections along the western and northern margins trapped much of the incoming sediment supply on the shelves and upper slopes. The late Miocene to Pliocene Cinco de Mayo unit, therefore, represents a relatively starved interval. In contrast, the uppermost, or Sigsbee unit, includes the Mississippi Fan, an accumulation up to 3 km (10,000 ft) thick of mainly mass-transported deposits that bypassed the shelf and slope and were deposited directly onto the abyssal plain. In the western and southwestern portions of the deep basin, beyond the fan pinchout, the Pleistocene section is largely a continuation of the Pliocene suspension deposits.

  14. Sensitivity of the Amazon rainforest to convective storms

    Science.gov (United States)

    Negron Juarez, R. I.; Chambers, J. Q.; Rifai, S. W.; Urquiza Munoz, J. D.; Tello, R.; Alegria Munoz, W.; Marra, D.; Ribeiro, G.; Higuchi, N.

    2012-12-01

    The Amazon rainforest is the largest contiguous continental tropical forest in the world and is a world center of carbon storage, biodiversity, biogeochemical cycles and biogeophysical processes that affect the Earth climate system. Yet anthropogenic activities have produced changes in the forest-climate system. Consequently, an increase in rainfall in both the Western and Central Amazon and a decrease in the Eastern Amazon are expected due to these anthropogenic activities. While the projected decrease in rainfall has been discussed under the context of drought, deforestation, and fires, the effect of an increase in rainfall, and associated convective processes, on forest ecosystems has been overlooked. Across the Amazon rainforest, Western Amazonia has the highest precipitation rates, wood productivity, soil fertility, recruitment and mortality rates. Yet our field-measured tree mortality data from blowdowns that occurred in Western and Central Amazonia do not show a statistical difference in tree mortality between these regions. However, downburst velocities associated with these disturbances were calculated to be lower in Western Amazonia than in the Central Amazon. This suggests the Western Amazon is more highly sensitive to intense convective systems. This result is particularly relevant given the expected increase in rainfall in the Western and Central Amazon. The increase in rainfall is associated with more intense convective systems that in turn imply an increase in low level jet stream (LLJ) intensity east of the Andes. The presence of the LLJ is the main cause of squall lines and an increase in LLJ intensity will therefore cause increased propagation of squall lines into the Amazon basin. More frequent and active squall lines have the potential to increase the intensity and frequency of downbursts responsible for large forest blowdowns that will affect the biogeophysical feedbacks on the forest ecosystem and carbon budget.

  15. Using satellite data to study the relationship between rainfall and diarrheal diseases in a Southwestern Amazon basin.

    Science.gov (United States)

    Fonseca, Paula Andrea Morelli; Hacon, Sandra de Souza; Reis, Vera Lúcia; Costa, Duarte; Brown, Irving Foster

    2016-03-01

    The North region is the second region in Brazil with the highest incidence rate of diarrheal diseases in children under 5 years old. The aim of this study was to investigate the relationship between rainfall and water level during the rainy season principally with the incidence rate of this disease in a southwestern Amazon basin. Rainfall estimates and the water level were correlated and both of them were correlated with the diarrheal incidence rate. For the Alto Acre region, 2 to 3 days' time-lag is the best interval to observe the impact of the rainfall in the water level (R = 0.35). In the Lower Acre region this time-lag increased (4 days) with a reduction in the correlation value was found. The correlation between rainfall and diarrheal disease was better in the Lower Acre region (Acrelândia, R = 0.7) and rainfall upstream of the city. Between water level and diarrheal disease, the best results were found for the Brasiléia gauging station (Brasiléia, R = 0.3; Epitaciolândia, R = 0.5). This study's results may support planning and financial resources allocation to prioritize actions for local Civil Defense and health care services before, during and after the rainy season.

  16. Adolescent pregnancies in the Amazon Basin of Ecuador: a rights and gender approach to adolescents' sexual and reproductive health.

    Science.gov (United States)

    Goicolea, Isabel

    2010-06-24

    In the Andean region of Latin America over one million adolescent girls get pregnant every year. Adolescent pregnancy (AP) has been associated with adverse health and social outcomes, but it has also been favorably viewed as a pathway to adulthood. AP can also be conceptualized as a marker of inequity, since it disproportionately affects girls from the poorest households and those who have not been able to attend school.Using results from a study carried out in the Amazon Basin of Ecuador, this paper explores APs and adolescents' sexual and reproductive health from a rights and gender approach. The paper points out the main features of a rights and gender approach, and how it can be applied to explore APs. Afterward it describes the methodologies (quantitative and qualitative) and main results of the study, framing the findings within the rights and gender approach. Finally, some implications that could be generalizable to global reserach on APs are highlighted.The application of the rights and gender framework to explore APs contributes to a more integral view of the issue. The rights and gender framework stresses the importance of the interaction between rights-holders and duty-bearers on the realization of sexual and reproductive rights, and acknowledges the importance of gender-power relations on sexual and reproductive decisions. A rights and gender approach could lead to more integral and constructive interventions, and it could also be useful when exploring other sexual and reproductive health matters.

  17. XX/XO, a rare sex chromosome system in Potamotrygon freshwater stingray from the Amazon Basin, Brazil.

    Science.gov (United States)

    de Souza Valentim, Francisco Carlos; Porto, Jorge Ivan Rebelo; Bertollo, Luiz Antonio Carlos; Gross, Maria Claudia; Feldberg, Eliana

    2013-09-01

    Potamotrygonidae is a representative family of South American freshwater elasmobranchs. Cytogenetic studies were performed in a Potamotrygon species from the middle Negro River, Amazonas, Brazil, here named as Potamotrygon sp. C. Mitotic and meiotic chromosomes were analyzed using conventional staining techniques, C-banding, and detection of the nucleolus organizing regions (NOR) with Silver nitrate (Ag-NOR). The diploid number was distinct between sexes, with males having 2n = 67 chromosomes, karyotype formula 19m + 8sm + 10st + 30a, and fundamental number (FN) = 104, and females having 2n = 68 chromosomes, karyotype formula 20m + 8sm + 10st + 30a, and FN = 106. A large chromosome, corresponding to pair number two in the female karyotype, was missing in the male complement. Male meiotic cells had 33 bivalents plus a large univalent chromosome in metaphase I, and n = 33 and n = 34 chromosomes in metaphase II. These characteristics are consistent with a sex chromosome system of the XX/XO type. Several Ag-NOR sites were identified in both male and female karyotypes. Positive C-banding was located only in the centromeric regions of the chromosomes. This sex chromosome system, which rarely occurs in fish, is now being described for the first time among the freshwater rays of the Amazon basin.

  18. Effect of artesunate-mefloquine fixed-dose combination in malaria transmission in amazon basin communities

    Directory of Open Access Journals (Sweden)

    Santelli Ana C

    2012-08-01

    Full Text Available Abstract Background Studies in South-East Asia have suggested that early diagnosis and treatment with artesunate (AS and mefloquine (MQ combination therapy may reduce the transmission of Plasmodium falciparum malaria and the progression of MQ resistance. Methods The effectiveness of a fixed-dose combination of AS and MQ (ASMQ in reducing malaria transmission was tested in isolated communities of the Juruá valley in the Amazon region. Priority municipalities within the Brazilian Legal Amazon area were selected according to pre-specified criteria. Routine national malaria control programmatic procedures were followed. Existing health structures were reinforced and health care workers were trained to treat with ASMQ all confirmed falciparum malaria cases that match inclusion criteria. A local pharmacovigilance structure was implemented. Incidence of malaria and hospitalizations were recorded two years before, during, and after the fixed-dose ASMQ intervention. In total, between July 2006 and December 2008, 23,845 patients received ASMQ. Two statistical modelling approaches were applied to monthly time series of P. falciparum malaria incidence rates, P. falciparum/Plasmodium vivax infection ratio, and malaria hospital admissions rates. All the time series ranged from January 2004 to December 2008, whilst the intervention period span from July 2006 to December 2008. Results The ASMQ intervention had a highly significant impact on the mean level of each time series, adjusted for trend and season, of 0.34 (95%CI 0.20 – 0.58 for the P. falciparum malaria incidence rates, 0.67 (95%CI 0.50 – 0.89 for the P. falciparum/P. vivax infection ratio, and 0.53 (95%CI 0.41 – 0.69 for the hospital admission rates. There was also a significant change in the seasonal (or monthly pattern of the time series before and after intervention, with the elimination of the malaria seasonal peak in the rainy months of the years following the introduction of ASMQ. No

  19. Oil development and health in the Amazon basin of Ecuador: the popular epidemiology process.

    Science.gov (United States)

    San Sebastián, Miguel; Hurtig, Anna Karin

    2005-02-01

    Recent decades have witnessed an increasing corporate access to and control over natural resources resulting in environmental degradation, inequalities and ill health. Since 1972, oil companies have extracted more than two billion barrels of crude oil from the Ecuadorian Amazon. During this process, millions of gallons of untreated toxic wastes, gas and oil have been released into the environment. Indigenous federations, peasant's movements and environmental groups have claimed that contamination has caused widespread damage to both people and the environment. This article tells the story of how the relationship between local organisations and research institutions developed around an epidemiological study constructed to address communities' concerns. Local organisations set the agenda of the research: they were involved in the hypothesis formulation, consulted in each step during the study and responsible of the dissemination of the findings. This process is known as popular epidemiology. Practical and personal issues and dilemmas faced during the research process are discussed with emphasis on the communication and dissemination of the findings. The article concludes the need of alliances between communities and researchers in order to protect health and environment. Popular epidemiology is an essential approach for public health researchers to reaffirm their roots in improving public health as a primary value.

  20. New dactylogyrids (Monogenea) parasitizing the gills of catfishes (Siluriformes) from the Amazon River basin in Peru.

    Science.gov (United States)

    Mendoza-Franco, Edgar F; Scholz, T

    2009-08-01

    Three dactylogyrid (Monogenea) species are described from the gills of siluriform fishes from the rivers around Iquitos, tributaries of the Amazon River in Peru: Demidospermus centromochli n. sp. from Centromochlus heckelii (de Filippi) (Auchenipteridae) and Demidospermus macropteri n. sp. and Ameloblastella unapi n. sp. from Calophysus macropterus (Lichtenstein) (Pimelodidae). The new species of Demidospermus differ from their congeners in having 2 different hook shapes. Ameloblastella unapi n. sp. differs from the other 3 species of the genus in having anchors with an elongate, straight shaft and a short point that forms a 90 degrees angle, a coiled (counterclockwise) male copulatory organ with 13-14 rings, and a coiled vaginal tube. Based on the present study, Pseudovancleaveus Franca, Issac, Pavanelli, and Takemoto, 2003, is regarded as a junior subjective synonym of Ameloblastella Kritsky, Mendoza-Franco, and Scholz, 2000. The finding of Demidospermus and Ameloblastella spp. on these siluriforms extends our host and geographic knowledge of species of these monogenean genera to Peru. PMID:19215149

  1. Influence of environmental variables on the density of shrub and tree seedlings in an Upland Forest in the Central Amazon

    Directory of Open Access Journals (Sweden)

    Randolpho Gonçalves Dias Terceiro

    2014-09-01

    Full Text Available This research aimed to evaluate the influence of luminosity and distance from an igarapé on seedling density in an upland forest in the Central Amazon. Twenty plots were installed, where we measured the percentage of canopy openness, and the distance from an igarapé, and we also counted the number of seedlings. We obtained a linear regression of canopy openness with the seedling density and an ANOVA of seedling density according to the distance from an igarapé. We registered a total of 229 seedling individuals (seedling density = 11 plants/m2. Among the environmental variables measured, only canopy openness has positively influenced on seedling density. Small amplitude in the increase in luminosity can cause an increased seedling density. Seedling density did not differ with regard to the distance from an igarapé, due to low competitiveness and adaptations by species occurring in the wetlands.

  2. Atmosphere-biosphere exchange of CO2 and O3 in the Central Amazon Forest

    Science.gov (United States)

    Fan, Song-Miao; Wofsy, Steven C.; Bakwin, Peter S.; Jacob, Daniel J.; Fitzjarrald, David R.

    1990-01-01

    An eddy correlation measurement of O3 deposition and CO2 exchange at a level 10 m above the canopy of the Amazon forest, conducted as part of the NASA/INPE ABLE2b mission during the wet season of 1987, is presented. It was found that the ecosystem exchange of CO2 undergoes a well-defined diurnal variation driven by the input of solar radiation. A curvilinear relationship was found between solar irradiance and uptake of CO2, with net CO2 uptake at a given solar irradiance equal to rates observed over forests in other climate zones. The carbon balance of the system appeared sensitive to cloud cover on the time scale of the experiment, suggesting that global carbon storage might be affected by changes in insolation associated with tropical climate fluctuations. The forest was found to be an efficient sink for O3 during the day, and evidence indicates that the Amazon forests could be a significant sink for global ozone during the nine-month wet period and that deforestation could dramatically alter O3 budgets.

  3. Neutrons, radiation and archaeology: a multi analytical case study of incised rim tradition ceramics in Central Amazon

    International Nuclear Information System (INIS)

    This thesis is an interdisciplinary archaeometric study involving archaeological ceramic material from two large archaeological sites in Central Amazon, namely Lago Grande and Osvaldo, on the confluence region of Negro and Solimoes rivers. It was tested a hypothesis about the existence of an exchange network between the former inhabitants of those sites, focusing on material and/or technological exchange. That hypothesis has implications for archaeological theories of human occupation of the pre-colonial Central Amazon, which try to relativise the role of ecological difficulties of the tropical forest as a limiting factor for the emergence of social complexity in the region. The physical-chemical characterization of potsherds and clay samples near the sites was carried out by: instrumental neutron activation analysis (INAA) to determine the elemental chemical composition; electron paramagnetic resonance (EPR) to determine the firing temperature; X-ray diffraction (XRD) to determine the mineralogical composition; and dating by optically stimulated luminescence (OSL). Previous studies showed that Osvaldo and Lago Grande were occupied by people which produced pottery classified in the Manacapuru and Paredao phases, subclasses of the Incised Rim Tradition, around the 5-10th and 7-12th centuries BC, respectively. INAA results were analyzed by multivariate statistical methods, whereby two chemical groups of pottery were defined for each archaeological site. Significant variation in firing temperatures and mineralogical composition were not identified for such groups. By integration of the results with archaeological data, the superposition between pairs of chemical groups was interpreted as a correlate of an ancient exchange network, although it was not possible to define if it existed exclusively between Lago Grande and Osvaldo. On the contrary, it was suggested that Lago Grande participated in a more extensive exchange network by comparison of two chemical groups

  4. A test of the cosmogenic 10Be(meteoric)/9Be proxy for simultaneously determining basin-wide erosion rates, denudation rates, and the degree of weathering in the Amazon basin

    Science.gov (United States)

    Wittmann, H.; Blanckenburg, F.; Dannhaus, N.; Bouchez, J.; Gaillardet, J.; Guyot, J. L.; Maurice, L.; Roig, H.; Filizola, N.; Christl, M.

    2015-12-01

    We present an extensive investigation of a new erosion and weathering proxy derived from the 10Be(meteoric)/9Be(stable) ratio in the Amazon River basin. This new proxy combines a radioactive atmospheric flux tracer, meteoric cosmogenic 10Be, with 9Be, a trace metal released by weathering. Results show that meteoric 10Be concentrations ([10Be]) and 10Be/9Be ratios increase by >30% from the Andes to the lowlands. We can calculate floodplain transfer times of 2-30 kyr from this increase. Intriguingly however, the riverine exported flux of meteoric 10Be shows a deficit with respect to the atmospheric depositional 10Be flux. Most likely, the actual area from which the 10Be flux is being delivered into the mainstream is smaller than the basin-wide one. Despite this imbalance, denudation rates calculated from 10Be/9Be ratios from bed load, suspended sediment, and water samples from Amazon Rivers agree within a factor of 2 with published in situ 10Be denudation rates. Erosion rates calculated from meteoric [10Be], measured from depth-integrated suspended sediment samples, agree with denudation rates, suggesting that grain size-induced variations in [10Be] are minimized when using such sampling material instead of bed load. In addition, the agreement between erosion and denudation rates implies minor chemical weathering intensity in most Amazon tributaries. Indeed, the Be-specific weathering intensity, calculated from mobilized 9Be comprising reactive and dissolved fractions that are released during weathering, is constant at approximately 40% of the total denudation from the Andes across the lowlands to the Amazon mouth. Therefore, weathering in the Amazon floodplain is not detected.

  5. Hydrochemistry of the Parauari-Maues Acu river basin (Amazon region, Brazil)

    International Nuclear Information System (INIS)

    The chemical composition of the Parauari-Maues Acu basin is studied through the determination of pH, calcium, magnesium, iron, chloride, sodium, potassium, zinc, copper and manganese. Four expeditions were made and samples were collected in 16 different points of the main course. Chemical analysis of the rivers waters shows seasonal flutuations of the concentrations of the elements in the main river as well as in the main afluents like Nambi river, Amana river and Urupadi river. (Author)

  6. Two new species of Pseudancistrus (Siluriformes, Loricariidae) from the Amazon basin, northern Brazil

    OpenAIRE

    Gabriel da Costa e Silva; Roxo, Fábio F; Claudio Oliveira

    2015-01-01

    Abstract Two new species of Pseudancistrus , a genus diagnosed by non-evertible cheek plates and hypertrophied odontodes along the snout margin, are described from two drainages of the Brazilian Shield: Pseudancistrus kayabi from the rio Teles Pires (rio Tapajós basin) and Pseudancistrus asurini from the rio Xingu. The new species are distinguished from congeners ( Pseudancistrus barbatus , Pseudancistrus corantijniensis , Pseudancistrus depressus , Pseudancistrus nigrescens , Pseudancistrus ...

  7. Impacts of extreme events of drought and flood on local communities of Amazon basin

    Science.gov (United States)

    Borma, L. D.; Roballo, S.; Zauner, M.; Nascimento, V. F.

    2013-05-01

    The analysis of drought events of 1997/98, 2005 and 2010 in terms of discharge anomalies in the Amazon region confirmed previous findings, such as: a) the influence of the El Niño in more than one hydrological year; b) the increase of the influence of the Atlantic Multidecadal Oscillation of 1998, 2005 and 2010 drought events; c) the low levels of discharge observed in the 2010 drought are attributed to the association of discharge anomalies of the northern and southern tributaries of the Amazon river, and d) the 2010 drought lasted around 1 month (August to November) more than the other drought events analized here. The riverine communities located along the river banks of Solimões/Amazonas suit their economic activities to the oscillation of the water level. In general, low water periods favor the access to important sources of food such as fish and livestock, still allowing crop cultivation on fertile agricultural areas of the floodplain. Conversely, periods of drought increases the difficulties of transport and drinking water supply. During the high water, access to the main food supply (described above) are greatly hampered. However, the floods are recognized as an importance process of natural fertilization. Thus, despite the political, social and economic shortcomings, the local community has, since the pre-colonial period, learned to get the best of each season, providing local, regional and national markets with varzea products. During periods of extreme weather, however, the advantages of each season appear to be reduced, and the drawbacks increased. In fact, during flooding extremes, the access to primary sources of food is hampered by a long period of time and families find themselves forced to leave their homes, eventually losing them. Analysis of flow data to the extreme flooding of 2009, indicate a period of about 6 months of positive anomalies discharge (occurring mainly during high water). At the same time, Civil Defense data points to a

  8. Highways and outposts: economic development and health threats in the central Brazilian Amazon region

    Directory of Open Access Journals (Sweden)

    Damacena Giseli N

    2010-06-01

    Full Text Available Abstract Background Economic development is often evoked as a driving force that has the capacity to improve the social and health conditions of remote areas. However, development projects produce uneven impacts on local communities, according to their different positions within society. This study examines the spatial distribution of three major health threats in the Brazilian Amazon region that may undergo changes through highway construction. Homicide mortality, AIDS incidence and malaria prevalence rates were calculated for 70 municipalities located within the areas of influence of the Cuiabá-Santarém highway (BR-163, i.e. in the western part of the state of Pará state and the northern part of Mato Grosso. Results The municipalities were characterized using social and economic indicators such as gross domestic product (GDP, urban and indigenous populations, and recent migration. The municipalities' connections to the region's main transportation routes (BR-163 and Trans-Amazonian highways, along with the Amazon and Tapajós rivers were identified by tagging the municipalities that have boundaries crossing these routes, using GIS overlay operations. Multiple regression was used to identify the major driving forces and constraints relating to the distribution of health threats. The main explanatory variables for higher malaria prevalence were: proximity to the Trans-Amazonian highway, high proportion of indigenous population and low proportion of migrants. High homicide rates were associated with high proportions of migrants, while connection to the Amazon River played a protective role. AIDS incidence was higher in municipalities with recent increases in GDP and high proportions of urban population. Conclusions Highways induce social and environmental changes and play different roles in spreading and maintaining diseases and health threats. The most remote areas are still protected against violence but are vulnerable to malaria. Rapid

  9. Petrology of ocean floor rocks from Central Indian Ocean basin

    Digital Repository Service at National Institute of Oceanography (India)

    Iyer, S.D.; Karisiddaiah, S.M.

    is discussed. It is believed that the basalts might have been the product of episodic eruption of submarine volcanoes. During the Deep Sea Drilling Project (DSDP) except for a single core drilling, not much work has been carried out in the Central Indian Ocean... Basin (C10B). Though information on petrological investigations ofthe Indian Ocean is available not much is known about the petrology of a major part of the C10B. During the course ofsurveys conducted by NrO for polymetallic nodules in ClOB, a large...

  10. Two new species of Pseudancistrus (Siluriformes, Loricariidae) from the Amazon basin, northern Brazil.

    Science.gov (United States)

    Silva, Gabriel S C; Roxo, Fábio F; Oliveira, Claudio

    2015-01-01

    Two new species of Pseudancistrus, a genus diagnosed by non-evertible cheek plates and hypertrophied odontodes along the snout margin, are described from two drainages of the Brazilian Shield: Pseudancistruskayabi from the rio Teles Pires (rio Tapajós basin) and Pseudancistrusasurini from the rio Xingu. The new species are distinguished from congeners (Pseudancistrusbarbatus, Pseudancistruscorantijniensis, Pseudancistrusdepressus, Pseudancistrusnigrescens, Pseudancistrusreus, and Pseudancistruszawadzkii) by the coloration pattern. Pseudancistruskayabi has dark bars on the dorsal and caudal fins which are similar to that of Pseudancistrusreus from the Caroní River, Venezuela. Pseudancistrusasurini is unique among Pseudancistrus in having whitish tips of the dorsal and caudal fins in juveniles to medium-sized adults.

  11. Mapping Aboveground Biomass in the Amazon Basin: Exploring Sensors, Scales, and Strategies for Optimal Data Linkage

    Science.gov (United States)

    Walker, W. S.; Baccini, A.

    2013-05-01

    Information on the distribution and density of carbon in tropical forests is critical to decision-making on a host of globally significant issues ranging from climate stabilization and biodiversity conservation to poverty reduction and human health. Encouraged by recent progress at both the international and jurisdictional levels on the design of incentive-based policy mechanisms to compensate tropical nations for maintaining their forests intact, governments throughout the tropics are moving with urgency to implement robust national and sub-national forest monitoring systems for operationally tracking and reporting on changes in forest cover and associated carbon stocks. Monitoring systems will be required to produce results that are accurate, consistent, complete, transparent, and comparable at sub-national to pantropical scales, and satellite-based remote sensing supported by field observations is widely-accepted as the most objective and cost-effective solution. The effectiveness of any system for large-area forest monitoring will necessarily depend on the capacity of current and near-future Earth observation satellites to provide information that meets the requirements of developing monitoring protocols. However, important questions remain regarding the role that spatially explicit maps of aboveground biomass and carbon can play in IPCC-compliant forest monitoring systems, with the majority of these questions stemming from doubts about the inherit sensitivity of satellite data to aboveground forest biomass, confusion about the relationship between accuracy and resolution, and a general lack of guidance on optimal strategies for linking field reference and remote sensing data sources. Here we demonstrate the ability of a state-of-the-art satellite radar sensor, the Japanese ALOS/PALSAR, and a venerable optical platform, Landsat 5, to support large-area mapping of aboveground tropical woody biomass across a 153,000-km2 region in the southwestern Amazon

  12. Automatic calibration of a global flow routing model in the Amazon basin using virtual SWOT data

    Science.gov (United States)

    Rogel, P. Y.; Mouffe, M.; Getirana, A.; Ricci, S. M.; Lion, C.; Mognard, N. M.; Biancamaria, S.; Boone, A.

    2012-12-01

    The Surface Water and Ocean Topography (SWOT) wide swath altimetry mission will provide a global coverage of surface water elevation, which will be used to help correct water height and discharge prediction from hydrological models. Here, the aim is to investigate the use of virtually generated SWOT data to improve water height and discharge simulation using calibration of model parameters (like river width, river depth and roughness coefficient). In this work, we use the HyMAP model to estimate water height and discharge on the Amazon catchment area. Before reaching the river network, surface and subsurface runoff are delayed by a set of linear and independent reservoirs. The flow routing is performed by the kinematic wave equation.. Since the SWOT mission has not yet been launched, virtual SWOT data are generated with a set of true parameters for HyMAP as well as measurement errors from a SWOT data simulator (i.e. a twin experiment approach is implemented). These virtual observations are used to calibrate key parameters of HyMAP through the minimization of a cost function defining the difference between the simulated and observed water heights over a one-year simulation period. The automatic calibration procedure is achieved using the MOCOM-UA multicriteria global optimization algorithm as well as the local optimization algorithm BC-DFO that is considered as a computational cost saving alternative. First, to reduce the computational cost of the calibration procedure, each spatially distributed parameter (Manning coefficient, river width and river depth) is corrupted through the multiplication of a spatially uniform factor that is the only factor optimized. In this case, it is shown that, when the measurement errors are small, the true water heights and discharges are easily retrieved. Because of equifinality, the true parameters are not always identified. A spatial correction of the model parameters is then investigated and the domain is divided into 4 regions

  13. Synthesis of morphotectonics and volcanics of the Central Indian Ocean Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Mukherjee, A.D.; Iyer, S.D.

    The Central Indian Ocean Basin (CIOB) is an enigmatic ocean basin in the young and tectonically complex Indian Ocean. Major tectonic and volcanic forms identified are fracture zones, abyssal hills, seamounts and ridges and a unique zone...

  14. Insights from Integrative Systematics Reveal Cryptic Diversity in Pristimantis Frogs (Anura: Craugastoridae) from the Upper Amazon Basin

    Science.gov (United States)

    Ortega-Andrade, H. Mauricio; Rojas-Soto, Octavio R.; Valencia, Jorge H.; Espinosa de los Monteros, Alejandro; Morrone, Juan J.; Ron, Santiago R.; Cannatella, David C.

    2015-01-01

    Pluralistic approaches to taxonomy facilitate a more complete appraisal of biodiversity, especially the diversification of cryptic species. Although species delimitation has traditionally been based primarily on morphological differences, the integration of new methods allows diverse lines of evidence to solve the problem. Robber frogs (Pristimantis) are exemplary, as many of the species show high morphological variation within populations, but few traits that are diagnostic of species. We used a combination of DNA sequences from three mitochondrial genes, morphometric data, and comparisons of ecological niche models (ENMs) to infer a phylogenetic hypothesis for the Pristimantis acuminatus complex. Molecular phylogenetic analyses revealed a close relationship between three new species—Pristimantis enigmaticus sp. nov., P. limoncochensis sp. nov. and P. omeviridis sp. nov.—originally confused with Pristimantis acuminatus. In combination with morphometric data and geographic distributions, several morphological characters such as degree of tympanum exposure, skin texture, ulnar/tarsal tubercles and sexual secondary characters (vocal slits and nuptial pads in males) were found to be useful for diagnosing species in the complex. Multivariate discriminant analyses provided a successful classification rate for 83–100% of specimens. Discriminant analysis of localities in environmental niche space showed a successful classification rate of 75–98%. Identity tests of ENMs rejected hypotheses of niche equivalency, although not strongly because the high values on niche overlap. Pristimantis acuminatus and P. enigmaticus sp. nov. are distributed along the lowlands of central–southern Ecuador and northern Peru, in contrast with P. limoncochensis sp. nov. and P. omeviridis sp. nov., which are found in northern Ecuador and southern Colombia, up to 1200 m in the upper Amazon Basin. The methods used herein provide an integrated framework for inventorying the greatly

  15. Genetic analysis of South American eastern equine encephalomyelitis viruses isolated from mosquitoes collected in the Amazon Basin region of Peru.

    Science.gov (United States)

    Kondig, John P; Turell, Michael J; Lee, John S; O'Guinn, Monica L; Wasieloski, Leonard P

    2007-03-01

    Identifying viral isolates from field-collected mosquitoes can be difficult and time-consuming, particularly in regions of the world where numerous closely related viruses are co-circulating (e.g., the Amazon Basin region of Peru). The use of molecular techniques may provide rapid and efficient methods for identifying these viruses in the laboratory. Therefore, we determined the complete nucleotide sequence of two South American eastern equine encephalomyelitis viruses (EEEVs): one member from the Peru-Brazil (Lineage II) clade and one member from the Argentina-Panama (Lineage III) clade. In addition, we determined the nucleotide sequence for the nonstructural P3 protein (nsP3) and envelope 2 (E2) protein genes of 36 additional isolates of EEEV from mosquitoes captured in Peru between 1996 and 2001. The 38 isolates were evenly distributed between lineages II and III virus groupings. However, analysis of the nsP3 gene for lineage III strongly suggested that the 19 isolates from this lineage could be divided into two sub-clades, designated as lineages III and IIIA. Compared with North American EEEV (lineage I, GA97 strain), we found that the length of the nsP3 gene was shorter in the strains isolated from South America. A total of 60 nucleotides was deleted in lineage II, 69 in lineage III, and 72 in lineage IIIA. On the basis of the sequences we determined for South American EEEVs and those for other viruses detected in the same area, we developed a series of primers for characterizing these viruses.

  16. Factors affecting Hg (II adsorption in soils from the Rio Negro basin (Amazon

    Directory of Open Access Journals (Sweden)

    Patricia Miretzky

    2005-06-01

    Full Text Available Mercury (II adsorption studies in top soils (top 10 cm from the Rio Negro basin show this process depends strongly on some selected parameters of the aqueous phase in contact with the soils. Maximum adsorption occurred in the pH range 3.0-5.0 (>90%. Dissolved organic matter shows an inhibitory effect on the availability of Hg (II to be adsorbed by the soils, whereas a higher chloride content of the solution resulted in a lower adsorption of Hg (II at pH 5.0. Soils with higher organic matter content were less affected by changes in the salinity. An increase in the initial Hg (II concentration increased the amount of Hg (II adsorbed by the soil and decreased the time needed to reach equilibrium. A Freundlich isotherm provided a good model for Hg (II adsorption in the two types of soil studied. The kinetics of Hg (II adsorption on Amazonian soils showed to be very fast and followed pseudo-second order kinetics. An environmental implication of these results is discussed under the real scenario present in the Negro River basin, where acidic waters are in contact with a soil naturally rich in mercury.

  17. An Intensive Study of Aerosol Optical Properties in the Outflow of the Manaus Urban Plume, in Central Amazon

    Science.gov (United States)

    Artaxo, P.; Cirino, G. G.; Brito, J.; Rizzo, L. V.; Barbosa, H. M.; Carbone, S.; Holanda, B. A.; Souza, R. A. F. D.; Tota, J.; Martin, S. T.

    2015-12-01

    In this study, one year of ground-based observations of aerosol optical properties from a site impacted by urban emissions in Central Amazon of Brazil are assessed as part of results from GoAmazon2014/5 experiment. The aerosol absorption (σa) and scattering (σs) coefficients, as well as single scattering albedo (SSA) are analyzed to aid in characterizing Manaus' urban aerosol at GoAmazon T2 site. There is a distinct diurnal variation for (σa) it was mainly attributed to the severe emission of particulate pollutants and black carbon during the morning and evening traffic rush hours. The decrease of (σa) nearly at noon (12:00-14:00 LT) was a result of strong atmospheric mixing and dilution due to the elevated height of atmospheric planetary boundary layer (PBL). After sunset (18:00 LT), the formation of stable nocturnal PBL even in atmospheric inversion led to a low atmospheric diffusion ability to aerosols and thus relatively high (σa) and (σs) throughout the night. Indeed, it was observed a strong dependence on local wind confirmed by simulated back trajectories in all two seasons. Overall, the wind dependence results provide valuable information about the locations of aerosol pollution sources and suggest that the air pollution in dry season is a regional problem but in the wet season it is mainly affected by local urban emissions. We have also seen an interesting difference in variability of (σs) and (σa) during 8:00-13:00 LT in wet season. A clear decrease was observed for (σa), while a smooth increase during 11:00-13:00 LT was presented for (σs). This is possibly a consequence of secondary aerosol production. (σa) is controlled to a large degree by primary aerosols such as black carbon that are emitted directly from pollution sources like vehicles, while (σs) is related to secondary aerosols such as sulfate and nitrate that contribute the most to light scattering. SSA was relatively low around 7:00-08:00 LT, which reflected that (σa) increased more

  18. The Floating Forest: Traditional Knowledge and Use of Matupá Vegetation Islands by Riverine Peoples of the Central Amazon

    Science.gov (United States)

    de Freitas, Carolina T.; Shepard, Glenn H.; Piedade, Maria T. F.

    2015-01-01

    Matupás are floating vegetation islands found in floodplain lakes of the central Brazilian Amazon. They form initially from the agglomeration of aquatic vegetation, and through time can accumulate a substrate of organic matter sufficient to grow forest patches of several hectares in area and up to 12 m in height. There is little published information on matupás despite their singular characteristics and importance to local fauna and people. In this study we document the traditional ecological knowledge of riverine populations who live near and interact with matupás. We expected that their knowledge, acquired through long term observations and use in different stages of the matupá life cycle, could help clarify various aspects about the ecology and natural history of these islands that field biologists may not have had the opportunity to observe. Research was carried out in five riverine communities of the Amanã Sustainable Development Reserve (Brazil). Semi-structured interviews were conducted with 45 inhabitants in order to register local understandings of how matupás are formed, biotic/abiotic factors related to their occurrence, the plants and animals that occur on them, their ecological relevance, and local uses. Local people elucidated several little-known aspects about matupá ecology, especially regarding the importance of seasonal dynamics of high/low water for matupás formation and the relevance of these islands for fish populations. Soil from matupás is especially fertile and is frequently gathered for use in vegetable gardens. In some cases, crops are planted directly onto matupás, representing an incipient agricultural experiment that was previously undocumented in the Amazon. Matupás are also considered a strategic habitat for fishing, mainly for arapaima (Arapaima gigas). The systematic study of traditional ecological knowledge proved to be an important tool for understanding this little-known Amazonian landscape. PMID:25837281

  19. The floating forest: traditional knowledge and use of matupa vegetation islands by riverine peoples of the central Amazon.

    Directory of Open Access Journals (Sweden)

    Carolina T de Freitas

    Full Text Available Matupás are floating vegetation islands found in floodplain lakes of the central Brazilian Amazon. They form initially from the agglomeration of aquatic vegetation, and through time can accumulate a substrate of organic matter sufficient to grow forest patches of several hectares in area and up to 12 m in height. There is little published information on matupás despite their singular characteristics and importance to local fauna and people. In this study we document the traditional ecological knowledge of riverine populations who live near and interact with matupás. We expected that their knowledge, acquired through long term observations and use in different stages of the matupá life cycle, could help clarify various aspects about the ecology and natural history of these islands that field biologists may not have had the opportunity to observe. Research was carried out in five riverine communities of the Amanã Sustainable Development Reserve (Brazil. Semi-structured interviews were conducted with 45 inhabitants in order to register local understandings of how matupás are formed, biotic/abiotic factors related to their occurrence, the plants and animals that occur on them, their ecological relevance, and local uses. Local people elucidated several little-known aspects about matupá ecology, especially regarding the importance of seasonal dynamics of high/low water for matupás formation and the relevance of these islands for fish populations. Soil from matupás is especially fertile and is frequently gathered for use in vegetable gardens. In some cases, crops are planted directly onto matupás, representing an incipient agricultural experiment that was previously undocumented in the Amazon. Matupás are also considered a strategic habitat for fishing, mainly for arapaima (Arapaima gigas. The systematic study of traditional ecological knowledge proved to be an important tool for understanding this little-known Amazonian landscape.

  20. Relative influence of natural watershed properties and human disturbance on stream solute concentrations in the southwestern Brazilian Amazon basin

    Science.gov (United States)

    Biggs, Trent Wade; Dunne, Thomas; Domingues, Tomas Ferreira; Martinelli, Luiz Antonio

    2002-08-01

    We use a synoptic sampling of stream water to quantify the effect of soil type, rock type, deforestation extent determined by Landsat TM imagery, and urban population density on stream solute concentrations for 60 different watersheds in the dry season and 49 in the wet season in the southwestern Brazilian Amazon basin. Catchment areas range between 18 and 12,500 km2. Soil exchangeable cation content explains most of the variance in stream concentrations of cations, dissolved silicon (Si), and acid neutralizing capacity (ANC) in both forested and deforested basins based on regression analysis (R2 range 0.61-0.81), though the mechanism underlying the relationship is unknown. We use the relationship between soil exchangeable cation content and stream solute concentrations in forested catchments to estimate the predisturbance and postdisturbance signal concentrations of stream solutes for deforested watersheds. Signal concentrations of potassium (K), sodium (Na), and chloride (Cl) increase with deforestation extent for streams on gneiss, granite, and sedimentary rock in both the dry and wet seasons after the effect of soil type has been statistically removed. Sulfate (SO4) signal concentrations increase with deforestation extent in the dry season only. For catchments >40% deforested but with no urban populations, the ratios of disturbed to predisturbance stream concentrations range from 1.2 to 3.1 (K), 0.8 to 2.2 (Na), 0.7 to 2.7 (SO4), and 2.4 to 14.6 (Cl) in the dry season and 1.2 to 2.2 (K) and 0.6 to 3.4 (Cl) in the wet season. Urban population density strongly affects Cl and SO4 concentrations in both seasons and Na concentrations in the dry season; the urban signal comprises 40-58% of the dry season Cl signal and 83-89% of the wet season Cl signal for watersheds with >250 persons per km2. Streams on mica-schist, mafic rock and carbonate shale have higher concentrations of Ca, Mg, Si, and ANC than watersheds on gneiss, granite, tertiary sediments or sandstone for

  1. Two new species of Pseudancistrus (Siluriformes, Loricariidae from the Amazon basin, northern Brazil

    Directory of Open Access Journals (Sweden)

    Gabriel da Costa e Silva

    2015-02-01

    Full Text Available Two new species of Pseudancistrus, a genus diagnosed by non-evertible cheek plates and hypertrophied odontodes along the snout margin, are described from two drainages of the Brazilian Shield: P. kayabi from the rio Teles Pires (rio Tapajós basin and P. asurini from the rio Xingu. The new species are distinguished from congeners (P. barbatus, P. corantijniensis, P. depressus, P. nigrescens, P. reus, and P. zawadzkii by the coloration pattern. Pseudancistrus kayabi has dark bars on the dorsal and caudal fins which are similar to that of P. reus from the Caroní River, Venezuela. Pseudancistrus asurini is unique among Pseudancistrus in having whitish tips of the dorsal and caudal fins in juveniles to medium-sized adults.

  2. Paleogene Sediment Character of Mountain Front Central Sumatra Basin

    Directory of Open Access Journals (Sweden)

    P. A. Suandhi

    2014-07-01

    Full Text Available DOI: 10.17014/ijog.v8i3.164The SE-NW trending Mountain Front of Central Sumatra Basin is located in the southern part of the basin. The Mountain Front is elongated parallel to the Bukit Barisan Mountain, extending from the Regencies of North Padang Lawas (Gunung Tua in the northwest, Rokan Hulu, Kampar, Kuantan Singingi, and Inderagiri Hulu Regency in the southeast. The Palaeogene sediments also represent potential exploration objectives in Central Sumatra Basin, especially in the mountain front area. Limited detailed Palaeogene sedimentology information cause difficulties in hydrocarbon exploration in this area. Latest age information and attractive sediment characters based on recent geological fieldwork (by chaining method infer Palaeogene sediment potential of the area. The Palaeogene sedimentary rock of the mountain front is elongated from northwest to southeast. Thickness of the sedimentary unit varies between 240 - 900 m. Palynology samples collected recently indicate that the oldest sedimentary unit is Middle Eocene and the youngest one is Late Oligocene. This latest age information will certainly cause significant changes to the existing surface geological map of the mountain front area. Generally, the Palaeogene sediments of the mountain front area are syn-rift sediments. The lower part of the Palaeogene deposit consists of fluvial facies of alluvial fan and braided river facies sediments. The middle part consists of fluvial meandering facies, lacustrine delta facies, and turbidity lacustrine facies sediments. The upper part consists of fluvial braided facies and transitional marine facies sediments. Volcanism in the area is detected from the occurrence of volcanic material as lithic material and spotted bentonite layers in the middle part of the mountain front area. Late rifting phase is indicated by the presence of transitional marine facies in the upper part of the Palaeogene sediments.

  3. The biomass burning aerosol influence on precipitation over the Central Amazon: an observational study

    Directory of Open Access Journals (Sweden)

    W. A. Gonçalves

    2014-07-01

    Full Text Available Understanding the aerosol influence on clouds and precipitation is an important key to reduce uncertainties in simulations of climate change scenarios with regards to deforestation fires. Here, we associate rainfall characteristics obtained by an S-Band radar in the Amazon with in situ measurements of biomass burning aerosols for the entire year of 2009. The most important results were obtained during the dry semester (July–December. The results indicate that the aerosol influence on precipitating systems is modulated by the atmospheric instability degree. For stable atmospheres, the higher the aerosol concentration, the lower the precipitation over the region. On the other hand, for unstable cases, higher concentrations of particulate material are associated with more precipitation, elevated presence of ice and larger rain cells, which suggests an association with long lived systems. The results presented were statistically significant. However, due to the limitation imposed by the dataset used, some important features such as wet scavenging and droplet size distribution need further clarification. Regional climate model simulations in addition with new field campaigns could aggregate information to the aerosol/precipitation relationship.

  4. Formic and acetic acid over the central Amazon region, Brazil. I - Dry season

    Science.gov (United States)

    Andreae, M. O.; Andreae, T. W.; Talbot, R. W.; Harriss, R. C.

    1988-01-01

    The concentrations of formic and acetic acids in the gas phase, atmospheric aerosol, and rainwater samples collected in Amazonia at ground level and in the atmosphere during the Amazon Boundary Layer Experiment in July/August 1985 were analyzed by ion exchange chromatography. The diurnal behavior of both acids at ground level and their vertical distribution in the forest canopy point to the existence of vegetative sources as well as to production by chemical reactions in the atmosphere. The concentrations of formic and acetic acids in the gas phase were about 2 orders of magnitude higher than the corresponding concentrations in the atmospheric aerosol. In rainwater, the total formate and acetate represented about one half of the anion equivalents, in contrast to less than 10 percent of the soluble anionic equivalents contributed by these acids in the atmospheric aerosol. The observed levels of these ions in rainwater are considered to be the result of a combination of chemical reactions in hydrometeors and the scavenging of the gaseous acids by cloud droplets.

  5. Karyotype structure of Hypostomus cf. plecostomus (Linnaeus, 1758) from Tapajós River basin, Southern Amazon: occurrence of sex chromosomes (ZZ/ZW) and their evolutionary implications.

    Science.gov (United States)

    Oliveira, L C; Ribeiro, M O; Dutra, E S; Zawadzki, C H; Portela-Castro, A L B; Martins-Santos, I C

    2015-06-18

    Hypostomus is a group of fish with numerical and struc-tural karyotypic variability. Among them, only six species, three of which belong to the Amazon basin, show a sex chromosome. In this study, we present the karyotype structure of Hypostomus cf. plecos-tomus from the Teles Pires river basin in the municipality of Alta Flo-resta, MT. The species has 2n = 68 and the karyotype formula 14m+ 24sm+ 14st+ 16a [fundamental number (FN) = 120] in males and 15m+ 24sm+14st+15a (FN = 121) in females and sex chromosomes ZZ/ZW. Argyrophilic nucleolar organizer regions (AgNORs) were identified in two pairs of chromosomes at different positions: short arm of the pair 21and long arm of the pair 27, matching the signals displayed by 18S FISH and indicating multiple NORs. Analysis of band C detected few blocks of constitutive heterochromatin in the pericentromeric regions of most chromosomes and the telomeric regions of some pairs, includ-ing the nucleolar pair 21. However, large blocks on the long arm of the nucleolar pair 27 still stood out. GC-rich heterochromatin (CMA3) was visualized only coincidently with nucleolar sites. Mapping of 5S rDNA sites with FISH revealed markings in eight chromosomes, demonstrat-ing synteny between the 18S and 5S sites. The data obtained for H. cf. plecostomus are important for taxonomic studies of this Amazon com-plex "H. plecostomus group". The occurrence of sex chromosomes in Amazon species of Hypostomus suggests an evolutionary event that is independent of other species in the group.

  6. Potential effects of climate change on inundation patterns in the Amazon Basin

    Directory of Open Access Journals (Sweden)

    F. Langerwisch

    2013-06-01

    Full Text Available Floodplain forests, namely the Várzea and Igapó, cover an area of more than 97 000 km2. A key factor for their function and diversity is annual flooding. Increasing air temperature and higher precipitation variability caused by climate change are expected to shift the flooding regime during this century, and thereby impact floodplain ecosystems, their biodiversity and riverine ecosystem services. To assess the effects of climate change on the flooding regime, we use the Dynamic Global Vegetation and Hydrology Model LPJmL, enhanced by a scheme that realistically simulates monthly flooded area. Simulation results of discharge and inundation under contemporary conditions compare well against site-level measurements and observations. The changes of calculated inundation duration and area under climate change projections from 24 IPCC AR4 climate models differ regionally towards the end of the 21st century. In all, 70% of the 24 climate projections agree on an increase of flooded area in about one third of the basin. Inundation duration increases dramatically by on average three months in western and around one month in eastern Amazonia. The time of high- and low-water peak shifts by up to three months. Additionally, we find a decrease in the number of extremely dry years and in the probability of the occurrence of three consecutive extremely dry years. The total number of extremely wet years does not change drastically but the probability of three consecutive extremely wet years decreases by up to 30% in the east and increases by up to 25% in the west. These changes implicate significant shifts in regional vegetation and climate, and will dramatically alter carbon and water cycles.

  7. A new species of Lycengraulis Günther, 1868 (Clupeiformes: Engraulinae) from the Amazon basin, Brazil, with comments on Lycengraulis batesii (Günther, 1868).

    Science.gov (United States)

    Loeb, Marina Vianna; Alcântara, Ayda Vera

    2013-01-01

    A new species of Lycengraulis from the Amazon basin is described. Lycengraulis figueiredoi can be distinguished from L. grossidens by a short upper maxilla, its posterior margin not reaching the lower maxilla joint (vs. upper maxilla longer, its posterior margin reaching to or a little past of mandible joint). Lycengraulis figueiredoi can be distinguished also from L. poeyi by 26 to 31 anal-fin rays (vs. 21 to 23 anal-fin rays) and by 44 to 46 vertebrae (vs. 42 vertebrae), and from L. batesii by having the anal-fin origin at vertical through base of second to fifth dorsal-fin ray (vs. anal-fin origin at vertical through base of sixth to 10th dorsal-fin ray) and by 17-21 gill rakers on the lower branch of first gill arch (vs. 12-15 gill rakers on the lower branch of first gill arch). The new species occurs in the rio Purus, Negro, Trombetas and Solimões, in the Amazon basin, Brazil.

  8. Pollination Requirements and the Foraging Behavior of Potential Pollinators of Cultivated Brazil Nut (Bertholletia excelsa Bonpl.) Trees in Central Amazon Rainforest

    OpenAIRE

    M. C. Cavalcante; F.F Oliveira; Maués, M. M.; B. M. Freitas

    2012-01-01

    This study was carried out with cultivated Brazil nut trees (Bertholletia excelsa Bonpl., Lecythidaceae) in the Central Amazon rainforest, Brazil, aiming to learn about its pollination requirements, to know the floral visitors of Brazil nut flowers, to investigate their foraging behavior and to determine the main floral visitors of this plant species in commercial plantations. Results showed that B. excelsa is predominantly allogamous, but capable of setting fruits by geitonogamy. Nineteen be...

  9. Floodplain Organic Carbon Storage in the Central Yukon River Basin

    Science.gov (United States)

    Lininger, K.; Wohl, E.

    2014-12-01

    Floodplain storage of organic carbon is an important aspect of the global carbon cycle that is not well understood or quantified. Although it is understood that rivers transport organic carbon to the ocean, little is known about the quantity of stored carbon in boreal floodplains and the influence of fluvial processes on this storage. We present results on total organic carbon (TOC) content within the floodplains of two rivers, the Dall River and Preacher Creek, in the central Yukon River Basin in the Yukon Flats National Wildlife Refuge of Alaska. The results indicate that organic carbon storage is influenced by fluvial disturbance and grain size. The Dall River, which contains a large amount of floodplain carbon, is meandering and incised, with well-developed floodplain soils, a greater percentage of relatively old floodplain surfaces and a slower floodplain turnover time, and finer grain sizes. Preacher Creek stores less TOC, transports coarser grain sizes, and has higher rates of avulsion and floodplain turnover time. Within the floodplain of a particular river, large spatial heterogeneity in TOC content also exists as a function of depositional environment and age and vegetation community of the site. In addition, saturated regions of the floodplains, such as abandoned channels and oxbow lakes, contain more TOC compared to drier floodplain environments. Frozen alluvial soils likely contain carbon that could be released into the environment with melting permafrost, and thus quantifying the organic carbon content in the active layer of floodplain soils could provide insight into the characteristics of the permafrost beneath. The hydrology in these regions is changing due to permafrost melt, and floodplain areas usually saturated could be dried out, causing breakdown and outgassing of carbon stored in previously saturated soils. Ongoing work will result in a first-order estimate of active-layer floodplain carbon storage for the central Yukon River Basin.

  10. Aerosol optical properties in pristine and biomass burning areas in the Amazon Basin

    Science.gov (United States)

    Artaxo, P.; Rizzo, L.; Lucca, S.; Paixao, M.; Sena, E. T.; Cirino, G.; Arana, A.

    2011-12-01

    Aerosol physical and chemical properties were measured in two sites in Amazonia. The clean site is at Central Amazonia, close to Manaus. A second sampling site is located in Porto Velho, Rondonia, an area strongly affected by biomass burning emissions. Long term measurements, from February 2008 are being carried out in these two sites. In the pristine central Amazonia, measurements were taken at the Cuieiras forest site, tower TT34, 55 Km North of Manaus under dry conditions (RHMAAP 5012 absorption photometer in series with a nephelometer (TSI 3563) was used to measure aerosol absorption and scattering, respectively. Aerosol size distributions were measure using a TSI SMPS system. Aerosol composition, and several trace gases that helps to characterize aerosol sources were also measured. In Rondonia, a sampling station was installed close to the city of Porto Velho. Similar instrumentation as in Manaus was used in Rondonia. In the pristine Amazonian atmosphere, aerosol scattering coefficients ranged between 1 and 200 Mm-1 at 450 nm, while absorption ranged between 1 and 20 Mm-1 at 637 nm. A strong seasonal behavior was observed, with greater aerosol loadings during the dry season (Jul-Nov) as compared to the wet season (Dec-Jun). During the wet season in Manaus, aerosol scattering (450 nm) and absorption (637 nm) coefficients averaged, respectively, 14±22 and 0.9±0.8 Mm-1. Both optical coefficients were greatly increased during the dry season, averaging 58±35 Mm-1 and 4.1±3.8 Mm-1, correspondingly. Angstrom exponents for scattering were lower during the wet season (1.6±0.4) in comparison to the dry season (1.9±0.2), which is consistent with the shift from biomass burning aerosols. Single scattering albedo, calculated at 637 nm, did not show a significant seasonal variation, averaging 0.86 ± 0.06 and 0.86 ± 0.04, respectively for wet and dry season. In Rondonia, even in the wet season it was possible to observe a strong impact from anthropogenic sources

  11. The NH4+-NO3--Cl--SO42--H2O aerosol system and its gas phase precursors at a pasture site in the Amazon Basin: How relevant are mineral cations and soluble organic acids?

    NARCIS (Netherlands)

    Trebs, I.; Metzger, S.; Meixner, F.X.; Helas, G.N.; Hoffer, A.; Rudich, Y.; Falkovich, A.H.; Moura, M.A.L.; Silva, da R.S.; Artaxo, P.; Slanina, J.; Andreae, M.O.

    2005-01-01

    Real-time measurements of ammonia, nitric acid, hydrochloric acid, sulfur dioxide and the water-soluble inorganic aerosol species, ammonium, nitrate, chloride, and sulfate were performed at a pasture site in the Amazon Basin (Rondônia, Brazil). The measurements were made during the late dry season (

  12. Introduction: Observations and Modeling of the Green Ocean Amazon (GoAmazon2014/5)

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Scot T.; Artaxo, Paulo; Machado, L.A. T.; Manzi, A.; Souza, Rodrigo A.; Schumacher, Courtney; Wang, J.; Andreae, M. O.; Barbosa, Henrique; Fan, Jiwen; Fisch, G.; Goldstein, Allen H.; Guenther, A.; Jimenez, J. L.; Poschl, U.; Silva Dias, Maria Assuncao F.; Smith, J. N.; Wendisch, Manfred

    2016-04-19

    The Observations and Modeling of the Green Ocean Amazon (GoAmazon2014/5) Experiment was carried out in the environs of Manaus, Brazil, in the central region of the Amazon basin during two years from 1 January 2014 through 31 December 2015. The experiment focused on the complex interactions among vegetation, atmospheric chemistry, and aerosol production on the one hand and their connections to aerosols, clouds, and precipitation on the other. The objective was to understand and quantify these linked processes, first under natural conditions to obtain a baseline and second when altered by the effects of human activities. To this end, the pollution plume from the Manaus metropolis, superimposed on the background conditions of the central Amazon basin, served as a natural laboratory. The present paper, as Introduction to the GoAmazon2014/5 Special Issue, presents the context and motivation of the GoAmazon2014/5 Experiment. The nine research sites, including the characteristics and instrumentation of each site, are presented. The sites range from time point zero (T0) upwind of the pollution, to T1 in the midst of the pollution, to T2 just downwind of the pollution, to T3 furthest downwind of the pollution (70 km). In addition to the ground sites, a low-altitude G-159 Gulfstream I (G1) observed the atmospheric boundary layer and low clouds, and a high-altitude Gulfstream G550 (HALO) operated in the free troposphere. During the two- year experiment, two Intensive Operating Periods (IOP1 and IOP2) also took place that included additional specialized research instrumentation at the ground sites as well as flights of the two aircraft. GoAmazon2014/5 IOP1 was carried out from 1 February to 31 March 2014 in the wet season. GoAmazon2014/5 IOP2 was conducted from 15 August to 15 October 2014 in the dry season. The G1 aircraft flew during both IOP1 and IOP2, and the HALO aircraft flew during IOP2. In the context of the Amazon basin, the two IOPs also correspond to the clean and

  13. Introduction: Observations and Modeling of the Green Ocean Amazon (GoAmazon2014/5)

    Science.gov (United States)

    Martin, S. T.; Artaxo, P.; Machado, L. A. T.; Manzi, A. O.; Souza, R. A. F.; Schumacher, C.; Wang, J.; Andreae, M. O.; Barbosa, H. M. J.; Fan, J.; Fisch, G.; Goldstein, A. H.; Guenther, A.; Jimenez, J. L.; Pöschl, U.; Silva Dias, M. A.; Smith, J. N.; Wendisch, M.

    2016-04-01

    The Observations and Modeling of the Green Ocean Amazon (GoAmazon2014/5) Experiment was carried out in the environs of Manaus, Brazil, in the central region of the Amazon basin for 2 years from 1 January 2014 through 31 December 2015. The experiment focused on the complex interactions among vegetation, atmospheric chemistry, and aerosol production on the one hand and their connections to aerosols, clouds, and precipitation on the other. The objective was to understand and quantify these linked processes, first under natural conditions to obtain a baseline and second when altered by the effects of human activities. To this end, the pollution plume from the Manaus metropolis, superimposed on the background conditions of the central Amazon basin, served as a natural laboratory. The present paper, as the introduction to the special issue of GoAmazon2014/5, presents the context and motivation of the GoAmazon2014/5 Experiment. The nine research sites, including the characteristics and instrumentation of each site, are presented. The sites range from time point zero (T0) upwind of the pollution, to T1 in the midst of the pollution, to T2 just downwind of the pollution, to T3 furthest downwind of the pollution (70 km). In addition to the ground sites, a low-altitude G-159 Gulfstream I (G-1) observed the atmospheric boundary layer and low clouds, and a high-altitude Gulfstream G550 (HALO) operated in the free troposphere. During the 2-year experiment, two Intensive Operating Periods (IOP1 and IOP2) also took place that included additional specialized research instrumentation at the ground sites as well as flights of the two aircraft. GoAmazon2014/5 IOP1 was carried out from 1 February to 31 March 2014 in the wet season. GoAmazon2014/5 IOP2 was conducted from 15 August to 15 October 2014 in the dry season. The G-1 aircraft flew during both IOP1 and IOP2, and the HALO aircraft flew during IOP2. In the context of the Amazon basin, the two IOPs also correspond to the clean and

  14. Pull-apart origin of the Satpura Gondwana basin, central India

    Indian Academy of Sciences (India)

    Chandan Chakraborty; Sanjoy Kumar Ghosh

    2005-06-01

    The Gondwana basins of peninsular India are traditionally considered as extensional-rift basins due to the overwhelming evidence of fault-controlled synsedimentary subsidence. These basins indeed originated under a bulk extensional tectonic regime, due to failure of the attenuated crust along pre-existing zones of weakness inherited from Precambrian structural fabrics. However, disposition of the basins and their structural architecture indicate that the kinematics of all the basins cannot be extensional. To maintain kinematic compatibility with other basins as well as the bulk lateral extension, some basins ought to be of strike-slip origin. The disposition, shape and structural architecture of the Satpura basin, central India suggest that the basin could be a pull-apart basin that developed above a releasing jog of a left-stepping strike-slip fault system defined by the Son-Narmada south fault and Tapti north fault in consequence to sinistral displacement along WSW-ENE. Development of a sedimentary basin under the above-mentioned kinematic condition was simulated in model experiments with sandpack. The shape, relative size, stratigraphic and structural architecture of the experimental basin tally with that of the Satpura basin. The experimental results also provide insights into the tectono-sedimentary evolution of the Satpura basin in particular and pull-apart basins in general.

  15. A scaling approach to Budyko's framework and the complementary relationship of evapotranspiration in humid environments: case study of the Amazon River basin

    Directory of Open Access Journals (Sweden)

    A. M. Carmona

    2015-10-01

    Full Text Available This paper studies a 3-D generalization of Budyko's framework designed to capture the mutual interdependence among long-term mean actual evapotranspiration (E, potential evapotranspiration (Ep and precipitation (P. For this purpose we use three dimensionless and dependent quantities: Ψ = E/P, Φ = Ep/P and Ω = E/Ep. This 3-D space and its 2-D projections provide an interesting setting to test the physical soundness of Budyko's hypothesis. We demonstrate analytically that Budyko-type equations are unable to capture the physical limit of the relation between Ω and Φ in humid environments, owing to the unfeasibility of Ep/P → 0 at E/Ep = 1. Using data from 146 sub-catchments in the Amazon River basin we overcome this inconsistency by proposing a physically consistent power law: Ψ = k Φe, with k = 0.66, and e = 0.83 (R2 = 0.93. This power law is compared with two other Budyko-type equations. Taking into account the goodness of fits and the ability to comply with the physical limits of the 3-D space, our results show that the power law is better suited to model the coupled water and energy balances within the Amazon River basin. Moreover, k is found to be related to the partitioning of energy via evapotranspiration in terms of Ω. This suggests that our power law implicitly incorporates the complementary relationship of evapotranspiration into the Budyko curve, which is a consequence of the dependent nature of the studied variables within our 3-D space. This scaling approach is also consistent with the asymmetrical nature of the complementary relationship of evapotranspiration. Looking for a physical explanation for the parameters k and e, the inter-annual variability of individual catchments is studied. Evidence of space–time symmetry in Amazonia emerges, since both between-catchment and between-year variability follow the same Budyko curves. Finally, signs of co-evolution of catchments are explored by linking spatial patterns of the power

  16. A scaling approach to Budyko's framework and the complementary relationship of evapotranspiration in humid environments: case study of the Amazon River basin

    Science.gov (United States)

    Carmona, A. M.; Poveda, G.; Sivapalan, M.; Vallejo-Bernal, S. M.; Bustamante, E.

    2016-02-01

    This paper studies a 3-D state space representation of Budyko's framework designed to capture the mutual interdependence among long-term mean actual evapotranspiration (E), potential evapotranspiration (Ep) and precipitation (P). For this purpose we use three dimensionless and dependent quantities: Ψ = E ⁄ P, Φ = Ep ⁄ P and Ω = E ⁄ Ep. This 3-D space and its 2-D projections provide an interesting setting to test the physical soundness of Budyko's hypothesis. We demonstrate analytically that Budyko-type equations are unable to capture the physical limit of the relation between Ω and Φ in humid environments, owing to the unfeasibility of Ep ⁄ P = 0 when E ⁄ Ep → 1. Using data from 146 sub-catchments in the Amazon River basin we overcome this inconsistency by proposing a physically consistent power law: Ψ = kΦe, with k = 0.66, and e = 0.83 (R2 = 0.93). This power law is compared with two other Budyko-type equations. Taking into account the goodness of fits and the ability to comply with the physical limits of the 3-D space, our results show that the power law is better suited to model the coupled water and energy balances within the Amazon River basin. Moreover, k is found to be related to the partitioning of energy via evapotranspiration in terms of Ω. This suggests that our power law implicitly incorporates the complementary relationship of evapotranspiration into the Budyko curve, which is a consequence of the dependent nature of the studied variables within our 3-D space. This scaling approach is also consistent with the asymmetrical nature of the complementary relationship of evapotranspiration. Looking for a physical explanation for the parameters k and e, the inter-annual variability of individual catchments is studied. Evidence of space-time symmetry in Amazonia emerges, since both between-catchment and between-year variability follow the same Budyko curves. Finally, signs of co-evolution of catchments are explored by linking spatial

  17. Fish assemblages of the Casiquiare River, a corridor and zoogeographical filter for dispersal between the Orinoco and Amazon basins

    Science.gov (United States)

    Winemiller, K.O.; Lopez-Fernandez, H.; Taphorn, D.C.; Nico, L.G.; Duque, A.B.

    2008-01-01

    Aim: The aim of this study was to determine whether the Casiquiare River functions as a free dispersal corridor or as a partial barrier (i.e. filter) for the interchange of fish species of the Orinoco and Negro/Amazon basins using species assemblage patterns according to geographical location and environmental features. Location: The Casiquiare, Upper Orinoco and Upper Negro rivers in southern Venezuela, South America. Methods: Our study was based on an analysis of species presence/absence data and environmental information (11 habitat characteristics) collected by the authors and colleagues between the years 1984 and 1999. The data set consisted of 269 sampled sites and 452 fish species (> 50,000 specimens). A wide range of habitat types was included in the samples, and the collection sites were located at various points along the entire length of the Casiquiare main channel, at multiple sites on its tributary streams, as well as at various nearby sites outside the Casiquiare drainage, within the Upper Orinoco and Upper Rio Negro river systems. Most specimens and field data used in this analysis are archived in the Museo de Ciencias Naturales in Guanare, Venezuela. We performed canonical correspondence analysis (CCA) based on species presence/absence using two versions of the data set: one that eliminated sites having < 5 species and species occurring at < 5 sites; and another that eliminated sites having < 10 species and species occurring at < 10 sites. Cluster analysis was performed on sites based on species assemblage similarity, and a separate analysis was performed on species based on CCA loadings. Results: The CCA results for the two versions of the data set were qualitatively the same. The dominant environmental axis contrasted assemblages and sites associated with blackwater vs. clearwater conditions. Longitudinal position on the Casiquiare River was correlated (r2 = 0.33) with CCA axis-1 scores, reflecting clearwater conditions nearer to its origin

  18. Three new species of the armored catfish genus Loricaria (Siluriformes: Loricariidae from river channels of the Amazon basin

    Directory of Open Access Journals (Sweden)

    Matthew R. Thomas

    2008-01-01

    Full Text Available Three new species of Loricaria are described from large white- and black-water river channels of the Amazon basin of Brazil, the upper rio Negro drainage of southern Venezuela, and clear waters of the lower rio Tocantins. Loricaria spinulifera and L. pumila differ from other species of Loricaria by having unique patterns of abdominal plate development and hypertrophied odontodes forming conspicuous crests on dorsal surfaces of the head and predorsal plates. Both are small species of Loricaria, reaching sexual maturity at less than 120 mm SL, and exhibiting sexually dimorphic characters consistent with members of the L. cataphracta complex. Loricaria spinulifera differs from L. pumila in having a unique arrangement of buccal papillae and large thorn-like odontodes on the dorsum of the head. Loricaria pumila is the smallest known Loricaria, reaching sexual maturity at less than 80 mm SL. Loricaria lundbergi differs from other Loricaria by having a unique abdominal plate pattern, broad head, and small basicaudal plate. Loricaria lundbergi is sympatric with L. spinulifera in the lower rio Negro drainage, but is also known from the rio Baria system of the Casiquiare drainage. Loricaria pumila occurs in the lower rio Amazonas and lower rio Tocantins. All three new species exhibit varying degrees of reduction in eye size and pigmentation seen in other fishes inhabiting deep river channels of South America.Três novas espécies de Loricaria são descritas provenientes dos canais de grandes rios de águas brancas e pretas da bacia Amazônica brasileira, da bacia do alto rio Negro no sul da Venezuela e das águas claras do baixo rio Tocantins. Loricaria lundbergi é simpátrica com L. spinulifera no baixo rio Negro, mas também é conhecida para o sistema do rio Baria, drenagem do Cassiquiare. Loricaria pumila ocorre no baixo rio Amazonas e baixo rio Tocantins. Loricaria spinulifera e L. pumila diferem de outras Loricaria por apresentarem odont

  19. Digital assessment of northern and central Appalachian basin coals

    Energy Technology Data Exchange (ETDEWEB)

    Ruppert, L.F.; Tewalt, S.J.; Braff, L.J.; Wallack, R.N. [US Geological Survey National Center, Reston, VA (US)

    1999-10-01

    The US Geological Survey (USGS) is currently conducting a coal resource assessment of the coalbeds and zones that are projected to provide the bulk of the nation's resources for the next few decades. The Pittsburgh and Upper Freeport coals are the first two beds in the northern and central Appalachian basin region to undergo fully digital coal assessments. The bed-specific assessments are being carried out in partnership with the state geologic surveys of West Virginia, Ohio, Pennsylvania and Maryland. Comprehensive stratigraphic and geochemical data-bases have been developed for both of the beds. The extent of the bed with mined areas, structure contour, isopach, and overburden thickness maps for the Pittsburgh coal bed have been realised as USGS open-file reports. The articles includes several detailed maps showing the export of the Pittsburgh coalbed, ash yield, sulphur contents and calorific value of the coal by county, structure contours, overburden thickness and isopac lines. 10 figs., 2 tabs.

  20. Effects of partial throughfall exclusion on the phenology of Coussarea racemosa (Rubiaceae) in an east-central Amazon rainforest.

    Science.gov (United States)

    Brando, Paulo; Ray, David; Nepstad, Daniel; Cardinot, Gina; Curran, Lisa M; Oliveira, Rafael

    2006-11-01

    Severe droughts may alter the reproductive phenology of tropical tree species, but our understanding of these effects has been hampered by confounded variation in drought, light and other factors during natural drought events. We used a large-scale experimental reduction of throughfall in an eastern-central Amazon forest to study the phenological response to drought of an abundant subcanopy tree, Coussarea racemosa. We hypothesized that drought would alter the production and the timing of reproduction, as well as the number of viable fruits. The study system comprised two 1-ha plots in the Tapajos National Forest, Para, Brazil: a dry plot where 50% of incoming precipitation (80% throughfall) was diverted from the soil during the six-month wet season beginning in January 2000, and a wet plot that received natural rainfall inputs. Fruit production of C. racemosa was quantified every 15 days using 100 litter traps (0.5 m(2)) in each plot. The production of new leaves and flowers was recorded monthly for C. racemosa individuals. Soil water, pre-dawn leaf water potential and solar radiation were measured to help interpret phenological patterns. Over the approximately 3.5-year period (April 2000 through December 2003), total fruit production remained similar between plots, declining by 12%. In 2003, production was four times higher in both plots than in previous years. In the dry plot, fruit fall shifted 40 and 60 days later into the dry season in 2002 and 2003, respectively. Total fruit fall dry mass production was variable across the study period. Foliage and flower production coincided with peak irradiance early in the dry season until delays in flowering appeared in the dry plot in 2002 and 2003. Plant water stress, through its influence on leaf developmental processes and, perhaps, inhibition of photosynthesis, appears to have altered both the timing of fruit fall and the quality and number of seeds produced. PMID:16955290

  1. Cytogenetic variation of repetitive DNA elements in Hoplias malabaricus (Characiformes - Erythrinidae) from white, black and clear water rivers of the Amazon basin.

    Science.gov (United States)

    Santos, Fabíola Araújo Dos; Marques, Diego Ferreira; Terencio, Maria Leandra; Feldberg, Eliana; Rodrigues, Luís Reginaldo R

    2016-03-01

    Hoplias malabaricus is a common fish species occurring in white, black and clear water rivers of the Amazon basin. Its large distribution across distinct aquatic environments can pose stressful conditions for dispersal and creates possibilities for the emergence of local adaptive profiles. We investigated the chromosomal localization of repetitive DNA markers (constitutive heterochromatin, rDNA and the transposable element REX-3) in populations from the Amazonas river (white water), the Negro river (black water) and the Tapajós river (clear water), in order to address the variation/association of cytogenomic features and environmental conditions. We found a conserved karyotypic macrostructure with a diploid number of 40 chromosomes (20 metacentrics + 20 submetacentrics) in all the samples. Heteromorphism in pair 14 was detected as evidence for the initial differentiation of an XX/XY system. Minor differences detected in the amount of repetitive DNA markers are interpreted as possible signatures of local adaptations to distinct aquatic environments.

  2. Impacts of satellite-based precipitation datasets on rainfall-runoff modeling of the Western Amazon basin of Peru and Ecuador

    Science.gov (United States)

    Zubieta, Ricardo; Getirana, Augusto; Espinoza, Jhan Carlo; Lavado, Waldo

    2015-09-01

    Satellites are an alternative source of rainfall data used as input to hydrological models in poorly gauged or ungauged regions. They are also useful in regions with highly heterogeneous precipitation, such as the tropical Andes. This paper evaluates three satellite precipitation datasets (TMPA, CMORPH, PERSIANN), as well as a dataset based only on rain gauge data (HYBAM), and their impacts on the water balance of the Western Amazon basin, a region where hydrological modeling and hydrological forecasting are poorly developed. These datasets were used as inputs in the MGB-IPH hydrological model to simulate streamflows for the 2003-2009 period. The impacts of precipitation on model parameterization and outputs were evaluated in two calibration experiments. In Experiment 1, parameter sets were separately defined for each catchment; in Experiment 2, a single parameter set was defined for the entire basin. TMPA shows overestimated precipitation over the northern region, while CMORPH and PERSIANN significantly underestimate rainfall in the same that region and along the Andes. TMPA and CMORPH lead to similar estimates of mean evapotranspiration (∼2 mm/day) for different regions along the entire basin, while PERSIANN is the least accurate (∼0.5 mm/day). Overall, better scores for streamflow simulations are obtained with Experiment 1 forced by HYBAM and TMPA. Nevertheless, results using the three satellite datasets indicate inter-basin differences, low performance in the northern and high in the southern regions. Low model performances are mainly related to scale issues and forcing errors in small basins over regions that present very low rainfall seasonality.

  3. Studies of palaeovegetation changes in the Central Amazon by carbon isotopes (12C, 13C, 14C) of soil organic matter

    International Nuclear Information System (INIS)

    The paper presents carbon isotope data δ13C and 14C on soil organic matter collected along an ecosystem transect in southern Amazon state, north-central Amazon region, that includes three distinct vegetation communities: savannah (Campos de Humaita), a savannah-forest transition and forest (Manaus). The study sites are located along road BR 319. Botanical identification and 13C analysis of modern vegetation in the savannah and forest sites indicate that most of the vegetation is C3 plants, although a few C4 plants are present at Campos de Humaita. The 13C and 14C data for soil organic matter in the Humaita region show that significant vegetation changes have occurred in the past, probably associated with climatic changes. During the early Holocene, forest vegetation extended throughout the study region, including areas occupied today by savannah vegetation. Savannah vegetation expanded at least 2 km into the modern forest ecotone during the middle Holocene, suggesting drier conditions. The last approximately 1000 years appear to indicate a recent expansion of forest vegetation, reflecting a return to a more moist climate. The study illustrates that the transition area between forest and savannah vegetation is quite sensitive to climatic changes, and this region should be the focus of more extensive research related to past climate and vegetation dynamics in the Amazon region. (author)

  4. Food resource partitioning in a fish community of the central Amazon floodplain

    Directory of Open Access Journals (Sweden)

    Bernard de Mérona

    2004-06-01

    Full Text Available Diets of most of fish species inhabiting a floodplain lake in central Amazonia were studied over a two years and half period. Based on the percentage of relative occurrence of 11 major food categories a classification of species in 11 feeding guilds is proposed. Many species were found to be specialized feeders. Fish, detritus and insects were the most important food resources supporting the fish community in both seasons, but the proportions of fruits, invertebrates and fish were reduced during the low water season. At the community level mean diet overlap between species was low, suggesting efficient resource partitioning within the community. However mean overlap between unspecialized feeders was high. Based on the 23 most abundant species belonging to the different feeding guilds, there was no difference in mean overlap between seasons. Whereas individual species exhibited diet changes between high water and low water seasons, there was no general pattern of seasonal change within feeding guilds.Os regimes alimentares da maioria das espécies de peixes de um lago de várzea da Amazônia central foram estudados durante dois anos e meio. Baseada nas percentagens de ocorrência relativa de 11 maiores categorias alimentares, uma classificação das espécies em 11 guildas alimentares é proposta. Muitas espécies foram consideradas especializadas em relação aos seus comportamentos alimentares. Peixes, detritos e insetos foram os recursos alimentares mais importantes ao longo do ano, mas as proporções relativas de frutos, invertebrados e peixes foram reduzidas durante a época de águas baixas. A nível de comunidade a sobreposição média entre espécies foi baixa, sugerindo uma partição eficiente dos recursos alimentares. Entretanto, para espécies não especializadas, os valores de sobreposição foram elevados. Baseado em 23 espécies abundantes, pertencentes a diferentes guildas alimentares, não foi observada diferença na sobreposi

  5. First Medicolegal Forensic Entomology Case of Central Amazon: A Suicide by Hanging with Incomplete Suspension

    Directory of Open Access Journals (Sweden)

    Eduardo Souza

    2014-04-01

    Resumo. Este relato descreve o primeiro caso de entomologia forense médico-legal na Amazônia Central. Um suicídio por enforcamento ocorrido em um platô de “terra firme” em floresta primária. A estimativa de intervalo pós-morte foi calculada com base na biologia da mosca varejeira Hemilucilia segmentaria (Fabricius e também pelo padrão de sucessão ecológica do besouro silfídeo Oxelytrum cayennense (Sturm. Este é o primeiro caso onde as informações ecológicas de um besouro foram usadas como indicador forense no Brasil. Estudos preliminares realizados em área urbana na cidade de Manaus e em hábitat semelhante em floresta primária, na Reserva Florestal Adolpho Ducke, próximo do local onde o caso ocorreu, foram fundamentais para ajudar para a estimativa do intervalo pós-morte.

  6. Petrology of seamounts in the Central Indian Ocean Basin: Evidence for near-axis origin

    Digital Repository Service at National Institute of Oceanography (India)

    Mukhopadhyay, R.; Batiza, R.; Iyer, S.D.

    Previous studies on the distribution and morphology of ancient seamount chains (>50 Ma) in the Central Indian Ocean basin (CIOB) indicated their generation from the fast spreading Southeast Indian Ridge. The petrology of some of these seamounts...

  7. Long-term changes in microbial and biochemical parameters in the Central Indian Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Raghukumar, C.; Nath, B.N.; Sharma, R.; LokaBharathi, P.A.; Dalal, S.G.

    Natural kilometer-scale spatial variability and seasonal variability in deepsea sediments at ~5000 m depth was studied at 2 reference sites in the Central Indian Basin. Biochemical parameters such as the labile organic matter (consisting...

  8. Variation in size, morphology and chemical composition of polymetallic nodules from the Central Indian Ocean Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Valsangkar, A.B.; Karisiddaiah, S.M.; Parthiban, G.

    Chemical composition of 613 polymetallic nodules from 150 stations in the Central Indian Ocean Basin (CIOB) are determined and variations in Mn, Fe, Cu, Ni, Co, Zn and moisture content are studied with respect to their size and surface texture...

  9. Categories used to classify the basin-fill deposits in the Central Valley

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital dataset contains the categories used to classify the basin-fill deposits in the Central Valley as either coarse-grained or fine-grained deposits. This...

  10. New ichthyoliths from ferromanganese crusts and nodules from the Central Indian Ocean Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Gupta, S.M.

    Ferromanganese encrusted hardgrounds, their intraclasts and the nuclei of manganese nodules collected from the Central Indian Ocean basin have yielded plentiful numbers of ichthyoliths. Forty well-knon ichthyoliths, one new type and 35 new subtypes...

  11. Australasian microtektites from the Central Indian Basin: Implications for ejecta distribution patterns

    Digital Repository Service at National Institute of Oceanography (India)

    ShyamPrasad, M.; Sudhakar, M.

    Microtektites belonging to the Australasian tektite strewn field have been recovered in one (SK-16/176) out of three cores examined from the Central Indian Basin. The microtektites have been identified based on their physical appearance...

  12. Marine mineral resources of the Central Indian Basin: Ferromanganese nodules and crusts

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, P.S.; Nair, R.R.

    The morphology, mineralogy and composition of ferromanganese nodules and crusts from the Central Indian Basin and southwestern flank of the Charlsberg Ridge have been characterized from the analyses of data and samples collected at more than 2000...

  13. Benthic disturbance and monitoring experiment in the Central Indian Ocean Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Sharma, R.; Nath, B.N.

    Environmental impact assessment studies for deep-sea manganese nodule mining have been initiated in the Central indian Ocean Basin since 1995. As a part of the first phase for collecting the benthic baseline data, echosounding, subbottom profiling...

  14. Somatosensory Psychophysical Losses in Inhabitants of Riverside Communities of the Tapajós River Basin, Amazon, Brazil: Exposure to Methylmercury Is Possibly Involved.

    Science.gov (United States)

    Khoury, Eliana Dirce Torres; Souza, Givago da Silva; da Costa, Carlos Araújo; de Araújo, Amélia Ayako Kamogari; de Oliveira, Cláudia Simone Baltazar; Silveira, Luiz Carlos de Lima; Pinheiro, Maria da Conceição Nascimento

    2015-01-01

    The purpose of this work was to evaluate the somatosensory system of methylmercury-exposed inhabitants living in the communities of the Tapajós river basin by using psychophysical tests and to compare with measurements performed in inhabitants of the Tocantins river basin. We studied 108 subjects from Barreiras and São Luiz do Tapajós, two communities of the Tapajós river basin, State of Pará, Amazon, Brazil, aged 13-53 years old. Mercury analysis was performed in head hair samples weighting 0.1-0.2 g by using atomic absorption spectrometry. Three somatosensory psychophysical tests were performed: tactile sensation threshold, vibration sensation duration, and two-point discrimination. Semmes-Weinstein 20 monofilaments with different diameters were used to test the tactile sensation in the lower lip, right and left breasts, right and left index fingers, and right and left hallux. The threshold was the thinner monofilament perceived by the subject. Vibration sensation was investigated using a 128 Hz diapason applied to the sternum, right and left radial sides of the wrist, and right and left outer malleoli. Two trials were performed at each place. A stopwatch recorded the vibration sensation duration. The two-point discrimination test was performed using a two-point discriminator. Head hair mercury concentration was significantly higher in mercury-exposed inhabitants of Tapajós than in non-exposed inhabitants of Tocantins (p basin is a possible but not a definitely proven cause for psychophysical somatosensory losses observed in their population. Additionally, the relatively simple psychophysical measures used in this work should be followed by more rigorous measures of the same population.

  15. Miocene transgression in the central and eastern parts of the Sivas Basin (Central Anatolia, Turkey) and the Cenozoic palaeogeographical evolution

    Science.gov (United States)

    Poisson, André; Vrielynck, Bruno; Wernli, Roland; Negri, Alessandra; Bassetti, Maria-Angela; Büyükmeriç, Yesim; Özer, Sacit; Guillou, Hervé; Kavak, Kaan S.; Temiz, Haluk; Orszag-Sperber, Fabienne

    2016-01-01

    We present here a reappraisal of the tectonic setting, stratigraphy and palaeogeography of the central part of the Sivas Basin from Palaeocene to late Miocene. The Sivas Basin is located in the collision zone between the Pontides (southern Eurasia) and Anatolia (a continental block rifted from Gondwana). The basin overlies ophiolites that were obducted onto Anatolia from Tethys to the north. The Central Anatolian Crystalline Complex (CACC) experienced similar ophiolite obduction during Campanian time, followed by exhumation and thrusting onto previously emplaced units during Maastrichtian time. To the east, crustal extension related to exhumation of the CACC created grabens during the early Tertiary, including the Sivas Basin. The Sivas Basin underwent several tectonic events during Paleogene-Neogene. The basin fill varies, with several sub-basins, each being characterised by a distinctive sequence, especially during Oligocene and Miocene. Evaporite deposition in the central part of the basin during early Oligocene was followed by mid-late Oligocene fluvio-lacustrine deposition. The weight of overlying fluvial sediments triggered salt tectonics and salt diapir formation. Lacustrine layers that are interbedded within the fluviatile sediments have locally yielded charophytes of late Oligocene age. Emergent areas including the pre-existing Sivas Basin and neighbouring areas were then flooded from the east by a shallow sea, giving rise to a range of open-marine sub-basins, coralgal reef barriers and subsiding, restricted-marine sub-basins. Utilising new data from foraminifera, molluscs, corals and nannoplankton, the age of the marine transgression is reassessed as Aquitanian. Specifically, age-diagnostic nannoplankton assemblages of classical type occur at the base of the transgressive sequence. However, classical stratigraphic markers have not been found within the planktic foraminiferal assemblages, even in the open-marine settings. In the restricted-marine sediments

  16. How many more dams in the Amazon?

    International Nuclear Information System (INIS)

    The Amazon watershed harbors a megadiversity of terrestrial and aquatic plants and animals. Mechanisms that sustain this biodiversity are the water level fluctuations the fluvial dynamics and the intense gene flux due to permanent integration of climatological, geomorphological and biological components of the system. The construction of hydroelectric reservoirs to support economic development of Brazil and other countries that share the Amazon basin will interfere with the ecological dynamics of this ecosystem changing the hydrological, hydrosocial and fundamental processes. Furthermore the construction of Andean reservoirs can disrupt the connectivity with the lower Amazon ecosystem. Principles of ecohydrologies, ecological engineering and preservation of key river basins, have to be applied in order to optimize energy production and promote conservation practices. Long term planning and integration of countries that share the Amazon basin is a strategic decision to control and develop the hydropower exploitation in the region. - Highlights: • The Amazon basin is an ecosystem of megadiversity. • The demand for energy threatens this ecosystem. • Climate, water, forests and floodplain interacts in the Amazon basin. • Dams in the Amazon basin will impact the hydrological and biological systems. • Ecohydrological principles and ecological engineering technology are necessary

  17. Annual Variations in Water Storage and Precipitation in the Amazon Basin: Bounding Sink Terms in the Terrestrial Hydrological Balance using GRACE Satellite Gravity Data

    Science.gov (United States)

    Crowley, John W.; Mitrovica, Jerry X.; Bailey, Richard C.; Tamisiea, Mark E.; Davis, James L.

    2007-01-01

    We combine satellite gravity data from the Gravity Recovery and Climate Experiment (GRACE) and precipitation measurements from the National Oceanic and Atmospheric Administration (NOAA) Climate Prediction Center's (CPC) Merged Analysis of Precipitation (CMAP) and the Tropical Rainfall Measuring Mission (TRMM), over the period from mid-2002 to mid-2006, to investigate the relative importance of sink (runoff and evaporation) and source (precipitation) terms in the hydrological balance of the Amazon Basin. When linear and quadratic terms are removed, the time series of land water storage variations estimated from GRACE exhibits a dominant annual signal of 250 mm peak-to-peak, which is equivalent to a water volume change of approximately 1800 cubic kilometers. A comparison of this trend with accumulated (i.e., integrated) precipitation shows excellent agreement and no evidence of basin saturation. The agreement indicates that the net runoff and evaporation contributes significantly less than precipitation to the annual hydrological mass balance. Indeed, raw residuals between the detrended water storage and precipitation anomalies range from plus or minus 40 mm. This range is consistent with streamflow measurements from the region, although the latter are characterized by a stronger annual signal than ow residuals, suggesting that runoff and evaporation may act to partially cancel each other.

  18. Characterization, analysis and dating of archaeological ceramics from the Amazon basin through nuclear techniques; Caracterizacao, analise e datacao de ceramicas arqueologicas da Bacia Amazonica atraves de tecnicas nucleares

    Energy Technology Data Exchange (ETDEWEB)

    Latini, Rose Mary

    1998-07-01

    The aim of this work is to contribute to the research in the reconstruction of part of the pre-history of the Amazon Basin by means of an analytical methods combined with multivariate analysis, given a analytic basis that can be continued by the archaeological work, through the identification, classification, provenance and dating the ceramics found in different archaeological sites of the Hydro graphic Basin of the Purus river. Neutron activation analysis in conjunction multivariate statistical methods were used for the identification and classification and thermoluminescence was used for the dating. Chemical composition results were in better agreement with archaeological classification for the archaeologically define Iquiri, Quinan and Xapuri phases and less characteristics the Iaco and Jacuru archaeological phase were not well characterized. An homogeneous group was established by most of the samples collected from the Los Angeles Archaeological Site (LA) and was distinct from all the other groups analysed. The provenance studies made with ceramics collected at this site shows that they were made with clay from nearby river (Rio Ina). From the LA ceramics dating the average date of site occupation was 1660 years. The ceramic dating results from the external wall of a circular earth wall construction confirm the relation with the local pre-history. Beyond the Acre material two urns were dated from the Archaeological Site Morro Grande and Sao Jose at Araruama, Rio de Janeiro. (author)

  19. Annual variations in water storage and precipitation in the Amazon Basin. Bounding sink terms in the terrestrial hydrological balance using GRACE satellite gravity data

    Science.gov (United States)

    Crowley, John W.; Mitrovica, Jerry X.; Bailey, Richard C.; Tamisiea, Mark E.; Davis, James L.

    2008-01-01

    We combine satellite gravity data from the gravity recovery and climate experiment (GRACE) and precipitation measurements from the National Oceanic and Atmospheric Administration (NOAA) Climate Prediction Center’s (CPC) Merged Analysis of Precipitation (CMAP) and the Tropical Rainfall Measuring Mission (TRMM), over the period from mid-2002 to mid-2006, to investigate the relative importance of sink (runoff and evaporation) and source (precipitation) terms in the hydrological balance of the Amazon Basin. When linear and quadratic terms are removed, the time-series of land water storage variations estimated from GRACE exhibits a dominant annual signal of 250 mm peak-to-peak, which is equivalent to a water volume change of ~1,800 km3. A comparison of this trend with accumulated (i.e., integrated) precipitation shows excellent agreement and no evidence of basin saturation. The agreement indicates that the net runoff and evaporation contributes significantly less than precipitation to the annual hydrological mass balance. Indeed, raw residuals between the de-trended water storage and precipitation anomalies range from ±40 mm. This range is consistent with stream-flow measurements from the region, although the latter are characterized by a stronger annual signal than our residuals, suggesting that runoff and evaporation may act to partially cancel each other.

  20. A new "Bat-Voiced" species of Dendropsophus Fitzinger, 1843 (Anura, Hylidae) from the Amazon Basin, Brazil.

    Science.gov (United States)

    Orrico, Victor G D; Peloso, Pedro L V; Sturaro, Marcelo J; Da Silva-Filho, Heriberto F; Neckel-Oliveira, Selvino; Gordo, Marcelo; Faivovich, Julián; Haddad, Célio F B

    2014-11-06

    We describe Dendropsophus ozzyi sp. nov., a new species of treefrog, tentatively included in the Dendropsophus microcephalus Group and most notably diagnosed by the presence of pointed fingers and an advertisement call with a very high dominant frequency. The new species is known from three localities in the Brazilian Amazon forest, two on western State of Pará and one (the type locality) in eastern State of Amazonas (03°56'50"S and 58°26'36"W, 45 m a.s.l.).

  1. Fauna de Hymenoptera em Ficus spp. (Moraceae na Amazônia Central, Brasil Fauna of Hymenoptera in Ficus spp. (Moraceae in the Central Amazon, Brazil

    Directory of Open Access Journals (Sweden)

    Alison G. Nazareno

    2007-12-01

    Full Text Available A interação Ficus (Moraceae - vespas de figo é considerada um dos exemplos mais extremos de mutualismo entre planta e inseto. Neste trabalho, descreve-se a fauna de vespas de figo associada a cinco espécies de Ficus na Amazônia Central, considerando alguns aspectos do modo de polinização nas espécies Ficus (Urostigma cremersii, Ficus (Urostigma greiffiana, Ficus (Urostigma mathewsii, Ficus (Urostigma pertusa e Ficus (Pharmacosycea maxima. O estudo foi desenvolvido durante o período de abril a julho de 2004 em Manaus e Presidente Figueiredo, Estado do Amazonas. O número de espécies de vespas de figo por hospedeiro variou de uma a 13. Vespas do gênero Pegoscapus Cameron, 1906, polinizadoras de Ficus (Urostigma spp., apresentam pentes coxais e bolsos torácicos adaptados à coleta e ao transporte de pólen, indicando modo ativo de polinização. No subgênero Pharmacosycea, a polinizadora do gênero Tetrapus Mayr, 1885, não apresenta estrutura morfológica adaptada ao transporte de pólen, condizente com o modo passivo de polinização. Além das vespas de figo, F. (Pharmacosyceae maxima e F. (Urostigma pertusa apresentaram associação com ácaros, formigas (Solenopsis sp., Formicidae, besouros (Staphylinidae e larvas de Diptera e Lepidoptera.The interaction between Ficus (Moraceae and fig wasps is considered one of the most extreme examples of plant-insect mutualism. In the present study, we reported the fig wasp fauna associated with five Ficus species in the Central Amazon, Brazil, and considered some aspects of the pollination mode found in Ficus (Urostigma cremersii, Ficus (Urostigma greiffiana, Ficus (Urostigma mathewsii, Ficus (Urostigma pertusa e Ficus (Pharmacosycea maxima. The study was carried out from April to July 2004, in the cities of Manaus and Presidente Figueiredo (state of Amazonas, Brazil. The number of fig wasp species per host tree varied from one to 13. Wasps of the genus Pegoscapus Cameron, 1906, pollinators of

  2. Isoprene photochemistry over the Amazon rainforest

    Science.gov (United States)

    Liu, Yingjun; Brito, Joel; Dorris, Matthew R.; Rivera-Rios, Jean C.; Seco, Roger; Bates, Kelvin H.; Artaxo, Paulo; Duvoisin, Sergio; Keutsch, Frank N.; Kim, Saewung; Goldstein, Allen H.; Guenther, Alex B.; Manzi, Antonio O.; Souza, Rodrigo A. F.; Springston, Stephen R.; Watson, Thomas B.; McKinney, Karena A.; Martin, Scot T.

    2016-05-01

    Isoprene photooxidation is a major driver of atmospheric chemistry over forested regions. Isoprene reacts with hydroxyl radicals (OH) and molecular oxygen to produce isoprene peroxy radicals (ISOPOO). These radicals can react with hydroperoxyl radicals (HO2) to dominantly produce hydroxyhydroperoxides (ISOPOOH). They can also react with nitric oxide (NO) to largely produce methyl vinyl ketone (MVK) and methacrolein (MACR). Unimolecular isomerization and bimolecular reactions with organic peroxy radicals are also possible. There is uncertainty about the relative importance of each of these pathways in the atmosphere and possible changes because of anthropogenic pollution. Herein, measurements of ISOPOOH and MVK + MACR concentrations are reported over the central region of the Amazon basin during the wet season. The research site, downwind of an urban region, intercepted both background and polluted air masses during the GoAmazon2014/5 Experiment. Under background conditions, the confidence interval for the ratio of the ISOPOOH concentration to that of MVK + MACR spanned 0.4-0.6. This result implies a ratio of the reaction rate of ISOPOO with HO2 to that with NO of approximately unity. A value of unity is significantly smaller than simulated at present by global chemical transport models for this important, nominally low-NO, forested region of Earth. Under polluted conditions, when the concentrations of reactive nitrogen compounds were high (>1 ppb), ISOPOOH concentrations dropped below the instrumental detection limit (Amazon rainforest.

  3. Water soluble inorganic trace gases and related aerosol compounds in the tropical boundary layer. An analysis based on real time measurements at a pasture site in the Amazon Basin

    OpenAIRE

    I. Trebs

    2005-01-01

    This dissertation investigates the behavior of water-soluble inorganic trace gases and related aerosol species in the tropical boundary layer. Mixing ratios of ammonia (NH3), nitric acid (HNO3), nitrous acid (HONO), hydrochloric acid (HCl), sulfur dioxide (SO;,) and the corresponding water-soluble aerosol species, ammonium (NH,,1), nitrate (NO3 ), nitrite (NO,), chloride (CI) and sulfate (SO,") were measured at a pasture site in the Amazon Basin (Rondónia, Brazil). Sampling was performed from...

  4. Estimation of erosion and sedimentation yield in the Ucayali river basin, a Peruvian tributary of the Amazon River, using ground and satellite methods

    Science.gov (United States)

    Santini, William; Martinez, Jean-Michel; Guyot, Jean-Loup; Espinoza, Raul; Vauchel, Philippe; Lavado, Waldo

    2014-05-01

    Since 2003, the works of HYBAM observatory (www.ore-hybam.org) has allowed to quantify with accuracy, precision and over a long period Amazon's main rivers discharges and sediments loads. In Peru, a network of 8 stations is regularly gauged and managed in association with the national meteorological and Hydrological service (SENAMHI), the UNALM (National Agrological University of La Molina) and the National Water Agency (ANA). Nevertheless, some current processes of erosion and sedimentation in the foreland basins are still little known, both in volumes and in localization. The sedimentary contributions of Andean tributaries could be there considerable, masking a very strong sedimentation in subsidence zones localized between the control points of the HYBAM's network. The development of spatial techniques such as the Altimetry and reflectance measurement allows us today to complete the ground's network: HYBAM's works have allowed establishing a relation between surface concentration and reflectance in Amazonian rivers (Martinez et al., 2009, Espinoza et al., 2012) and reconstituting water levels series (Calmant et al., 2006, 2008). If the difficulty of calibration of these techniques increases towards the upstream, their use can allow a first characterization of the tributaries contributions and sedimentation zones. At world level, erosion and sedimentation yields in the upper Ucayali are exceptional, favored by a marked seasonality in this region (Espinoza et al., 2009, Lavado, 2010, Pépin et al., 2010) and the presence of cells of extreme precipitation ("Hotspots") (Johnson et al., 1976, Espinoza et al, 2009a). The upper Ucayali drainage basin is a Piggyback where the River run with a low slope, parallel to the Andean range, deposing by gravity hundred millions a year of sands, silts and clays. In this work, we thus propose an estimation of sedimentation and erosion yield in the Ucayali river basin using ground and satellite methods.

  5. Holocene Environmental Changes from the Rio Curuá Record in the Caxiuanã Region, Eastern Amazon Basin

    Science.gov (United States)

    Behling, Hermann; da Costa, Marcondes Lima

    2000-05-01

    Holocene environments have been reconstructed by multiproxy studies of an 850-cm-long core from Rio Curuá dating to >8000 14C yr B.P. The low-energy river lies in the eastern Amazon rain forest in the Caxiuanã National Forest Reserve, 350 km west of Belém in northern Brazil. Sedimentological, mineralogical, and geochemical dates demonstrate that the deposits correspond to two different environments, sediments of an active river before 8000 14C yr B.P. and later a passive river system. The pollen analytical results indicate four different local and regional Holocene paleoenvironmental periods: (1) a transition to a passive fluvial system and a well-drained terra firme (unflooded upland) Amazon rain forest with very limited development of inundated forests (várzea and igapó) (>7990-7030 14C yr B.P.); (2) a sluggish river with a local Mauritia palm-swamp and similar regional vegetation, as before (7030-5970 14C yr B.P.); (3) a passive river, forming shallow lake conditions and with still-abundant terra firme forest in the study region (5970-2470 14C yr B.P.); and (4) a blocked river with high water levels and marked increase of inundated forests during the last 2470 14C yr B.P. Increased charcoal during this last period suggests the first strong presence of humans in this region. The Atlantic sea level rise was probably the major factor in paleoenvironmental changes, but high water stands might also be due to greater annual rainfall during the late Holocene.

  6. Tropical forest carbon balance: effects of field- and satellite-based mortality regimes on the dynamics and the spatial structure of Central Amazon forest biomass

    International Nuclear Information System (INIS)

    Debate continues over the adequacy of existing field plots to sufficiently capture Amazon forest dynamics to estimate regional forest carbon balance. Tree mortality dynamics are particularly uncertain due to the difficulty of observing large, infrequent disturbances. A recent paper (Chambers et al 2013 Proc. Natl Acad. Sci. 110 3949–54) reported that Central Amazon plots missed 9–17% of tree mortality, and here we address ‘why’ by elucidating two distinct mortality components: (1) variation in annual landscape-scale average mortality and (2) the frequency distribution of the size of clustered mortality events. Using a stochastic-empirical tree growth model we show that a power law distribution of event size (based on merged plot and satellite data) is required to generate spatial clustering of mortality that is consistent with forest gap observations. We conclude that existing plots do not sufficiently capture losses because their placement, size, and longevity assume spatially random mortality, while mortality is actually distributed among differently sized events (clusters of dead trees) that determine the spatial structure of forest canopies. (paper)

  7. Somatosensory Psychophysical Losses in Inhabitants of Riverside Communities of the Tapajos River Basin, Amazon, Brazil: Exposure to Methylmercury Is Possibly Involved.

    Directory of Open Access Journals (Sweden)

    Eliana Dirce Torres Khoury

    Full Text Available The purpose of this work was to evaluate the somatosensory system of methylmercury-exposed inhabitants living in the communities of the Tapajós river basin by using psychophysical tests and to compare with measurements performed in inhabitants of the Tocantins river basin. We studied 108 subjects from Barreiras and São Luiz do Tapajós, two communities of the Tapajós river basin, State of Pará, Amazon, Brazil, aged 13-53 years old. Mercury analysis was performed in head hair samples weighting 0.1-0.2 g by using atomic absorption spectrometry. Three somatosensory psychophysical tests were performed: tactile sensation threshold, vibration sensation duration, and two-point discrimination. Semmes-Weinstein 20 monofilaments with different diameters were used to test the tactile sensation in the lower lip, right and left breasts, right and left index fingers, and right and left hallux. The threshold was the thinner monofilament perceived by the subject. Vibration sensation was investigated using a 128 Hz diapason applied to the sternum, right and left radial sides of the wrist, and right and left outer malleoli. Two trials were performed at each place. A stopwatch recorded the vibration sensation duration. The two-point discrimination test was performed using a two-point discriminator. Head hair mercury concentration was significantly higher in mercury-exposed inhabitants of Tapajós than in non-exposed inhabitants of Tocantins (p < 0.01. When all subjects were divided in two groups independently of age-mercury-exposed and non-exposed-the following results were found: tactile sensation thresholds in mercury-exposed subjects were higher than in non-exposed subjects at all body parts, except at the left chest; vibration sensation durations were shorter in mercury-exposed than in non-exposed subjects, at all locations except in the upper sternum; two-point discrimination thresholds were higher in mercury-exposed than in non-exposed subjects at all

  8. Correction of Interferometric and Vegetation Biases in the SRTMGL1 Spaceborne DEM with Hydrological Conditioning towards Improved Hydrodynamics Modeling in the Amazon Basin

    Directory of Open Access Journals (Sweden)

    Sebastien Pinel

    2015-12-01

    Full Text Available In the Amazon basin, the recently released SRTM Global 1 arc-second (SRTMGL1 remains the best topographic information for hydrological and hydrodynamic modeling purposes. However, its accuracy is hindered by errors, partly due to vegetation, leading to erroneous simulations. Previous efforts to remove the vegetation signal either did not account for its spatial variability or relied on a single assumed percentage of penetration of the SRTM signal. Here, we propose a systematic approach over an Amazonian floodplain to remove the vegetation signal, addressing its heterogeneity by combining estimates of vegetation height and a land cover map. We improve this approach by interpolating the first results with drainage network, field and altimetry data to obtain a hydrological conditioned DEM. The averaged interferometric and vegetation biases over the forest zone were found to be −2.0 m and 7.4 m, respectively. Comparing the original and corrected DEM, vertical validation against Ground Control Points shows a RMSE reduction of 64%. Flood extent accuracy, controlled against Landsat and JERS-1 images, stresses improvements in low and high water periods (+24% and +18%, respectively. This study also highlights that a ground truth drainage network, as a unique input during the interpolation, achieves reasonable results in terms of flood extent and hydrological characteristics.

  9. The presence of sboA and spaS genes and antimicrobial peptides subtilosin A and subtilin among Bacillus strains of the Amazon basin.

    Science.gov (United States)

    Velho, Renata Voltolini; Basso, Ana Paula; Segalin, Jeferson; Costa-Medina, Luis Fernando; Brandelli, Adriano

    2013-03-01

    This report demonstrates the usefulness of PCR for the genes spaS and sboA as a means of identifying Bacillus strains with a potential to produce subtilin and subtilosin A. One collection strain and five Bacillus spp. isolated from aquatic environments in the Amazon basin were screened by PCR using primers for sboA and spaS designed specifically for this study. The sequences of the PCR products showed elevated homology with previously described spaS and sboA genes. Antimicrobial peptides were isolated from culture supernatants and analyzed by mass spectrometry. For all samples, the mass spectra revealed clusters with peaks at m/z 3300-3500 Da, corresponding to subtilosin A, subtilin and isoforms of these peptides. These results suggest that the antimicrobial activity of these strains may be associated with the production of subtilosin A and/or subtilin. The PCR used here was efficient in identifying novel Bacillus strains with the essential genes for producing subtilosin A and subtilin.

  10. The influence of changes in lifestyle and mercury exposure in riverine populations of the Madeira River (Amazon Basin) near a hydroelectric project.

    Science.gov (United States)

    Hacon, Sandra S; Dórea, José G; Fonseca, Márlon de F; Oliveira, Beatriz A; Mourão, Dennys S; Ruiz, Claudia M V; Gonçalves, Rodrigo A; Mariani, Carolina F; Bastos, Wanderley R

    2014-02-26

    In the Amazon Basin, naturally occurring methylmercury bioaccumulates in fish, which is a key source of protein consumed by riverine populations. The hydroelectric power-plant project at Santo Antônio Falls allows us to compare the Hg exposure of riverine populations sparsely distributed on both sides of the Madeira river before the area is to be flooded. From 2009 to 2011, we concluded a population survey of the area (N = 2,008; representing circa 80% of community residents) that estimated fish consumption and mercury exposure of riverine populations with different degrees of lifestyle related to fish consumption. Fish samples from the Madeira river (N = 1,615) and 110 species were analyzed for Hg. Hair-Hg was significantly lower (p < 0.001) in less isolated communities near to the capital of Porto Velho (median 2.32 ppm) than in subsistence communities in the Cuniã Lake, 180 km from Porto Velho city (median 6.3 ppm). Fish Hg concentrations ranged from 0.01 to 6.06 µg/g, depending on fish size and feeding behavior. Currently available fish in the Madeira river show a wide variability in Hg concentrations. Despite cultural similarities, riparians showed hair-Hg distribution patterns that reflect changes in fish-eating habits driven by subsistence characteristics.

  11. A new synonym for Pristimantis luscombei (Duellman and Mendelson 1995) and the description of a new species of Pristimantis from the upper Amazon basin (Amphibia: Craugastoridae).

    Science.gov (United States)

    Ortega-Andrade, H Mauricio; Venegas, Pablo J

    2014-12-12

    We consider Pristimantis achuar as junior synonym of P. luscombei, based on morphological and genetic evidence. Paratype specimens of P. luscombei are part of a new species, which lead to taxonomic confusion regarding the identity of P. luscombei. We describe and name this new species as Pristimantis miktos sp. nov. from Juyuintza, Pastaza province, eastern lowlands of Ecuador. Morphological diagnostic characters used to distinguish the new species from other brownish Amazonian Pristimantis are: (1) skin of dorsum shagreen with scattered tubercles or pustules; (2) tympanum prominent; (3) a thick X-shaped scapular dermal ridge in males; and (4) an orange iris in life. Pristimantis miktos is an inhabitant of the lowlands forests of the Pastaza and Napo drainages in eastern Ecuador and northern Loreto in Peru, reaching elevations of up to 350 m; P. luscombei is widely distributed in the upper Amazon Basin of Ecuador, northern Peru and extreme western Brazil, up to 1000 m. Phylogenetic analyses reveals that P. luscombei and the new species are not closest relatives, as also deduced from morphological evidence.

  12. A rewiew of the subgenus Trichopygomyia Barretto, 1962; with description of a new species from the brazilian Amazon Basin (Diptera: Psychodidae, Phlebotominae

    Directory of Open Access Journals (Sweden)

    Jorge R. Arias

    1983-12-01

    Full Text Available The subgenus Trichopygomyia Barreto, 1962 of the phlebotomine genus Lutzomyia França, 1924 is reviewed. This subgenus corresponds to the informal species group longispina of Theodor (1965. Lutzomyia (Trichopygomya ratcliffei n.sp. from the Brazilian Amazon Basin is described. Figures, keys, distribution maps and notes on ecology are presented for all the known forms. The better known species are most frequently encountered in armadillo burrows and, therefore, could well be vectors of Leishmania.O subgênero Trichopygomyia Barretto, 1962 do flebótomo Lutzomyia spp. França, 1924 é revisto e corresponde às espécies incomuns do grupo longispina de Theodor (1965. É também descrita Lutzomyia (Trichopygomyia ratcliffei n.sp. da Bacia Amazônica. Figuras, chaves, mapas de distribuição e notas sobre ecologia são apresentados para todas as formas conhecidas. As espécies mais conhecidas são freqüentemente encontradas em todas de tatu e, portanto, podem ser vetores de Leishmania.

  13. Manganese and Mercury Levels in Water, Sediments, and Children Living Near Gold-Mining Areas of the Nangaritza River Basin, Ecuadorian Amazon.

    Science.gov (United States)

    González-Merizalde, Max V; Menezes-Filho, José A; Cruz-Erazo, Claudia Teresa; Bermeo-Flores, Santos Amable; Sánchez-Castillo, María Obdulia; Hernández-Bonilla, David; Mora, Abrahan

    2016-08-01

    Artisanal and small-scale gold-mining activities performed in mountain areas of the Southern Ecuadorian Amazon have incorporated several heavy metals into the aquatic systems, thus increasing the risk of exposure in populations living in adjacent zones. Therefore, the objective of this study was to evaluate the contamination levels of mercury (Hg) and manganese (Mn) in several rivers of the Nangaritza River basin and assess the exposure in school-aged children residing near the gold-mining zones. River water and sediment samples were collected from a highly contaminated (HEx) and a moderately contaminated (MEx) zones. Hair Mn (MnH) and urinary Hg (HgU) levels were determined in school-aged children living in both zones. High concentrations of dissolved Mn were found in river waters of the HEx zone (between 2660 and 3990 µg l(-1)); however, Hg levels, in general, were lower than the detection limit (DL; gold-mining activities can not only produce mercurial contamination, that can also release other heavy metals (such as Mn) that may pose a risk to human health. PMID:27173830

  14. FORMATIVE MECHANISM OF AKAISHI MOUNTAINS AND ENREI BASIN IN CENTRAL JAPAN

    Institute of Scientific and Technical Information of China (English)

    Yasu'uchi KUBOTA; Takao YANO

    2001-01-01

    @@ 1 Introduction It is common in mobile belts that uplifting mountains are neighbored by synchronously subsiding basins.The coupling mechanism of such subsidence and uplift is an important target to clarify the dynamics of mobile belts.We investigate the coupled mountain uplift and basin subsidence in the Central Japan highland,the junction of three island arcs (the Northeast Japan,the Southwest Japan and the Izu-Ogasawara arcs).The highland over 3 000 m in height is composed of mountain ranges,plateaus and intramountain basins (Fig.1).

  15. FORMATIVE MECHANISM OF AKAISHI MOUNTAINS AND ENREI BASIN IN CENTRAL JAPAN

    Institute of Scientific and Technical Information of China (English)

    Yasu'uchi; KUBOTA; Takao; YANO

    2001-01-01

    1 Introduction  It is common in mobile belts that uplifting mountains are neighbored by synchronously subsiding basins.The coupling mechanism of such subsidence and uplift is an important target to clarify the dynamics of mobile belts.We investigate the coupled mountain uplift and basin subsidence in the Central Japan highland,the junction of three island arcs (the Northeast Japan,the Southwest Japan and the Izu-Ogasawara arcs).The highland over 3 000 m in height is composed of mountain ranges,plateaus and intramountain basins (Fig.1).……

  16. Oxygen and hydrogen isotope exchange of geopressured thermal water in the central Guanzhong basin

    Institute of Scientific and Technical Information of China (English)

    YU Juan; MA Zhi-yuan; WANG Zhao-wei; LI Wei-liang; SU Yan

    2009-01-01

    Geothermal water of Xi'an and Xianyang in the central Guanzhong basin is typically geopressured thermal water in China. δ18O and δD data of geopressured thermal water in Xi'an and Xianyang, combined with data from the perimeter of the basin, are analyzed to study features of hydrogen and oxygen shifts. The results show that 18O exchange of geothermal water at the pc-rimeter of the basin and in the non-geopressured thermal water in the center of the basin is not evident, while in most of the geo-pressured thermal water in the central basin, in cities such as Xi'an and Xianyang, significant oxygen exchange had taken place as well as hydrogen exchange, suggesting that isotope exchanges would slowly move the geothermal water system towards equilib-rium. Thermal water reservoirs in the central basin have passed through significant water-rock reactions. Moreover, the geothermal reservoir of Xianyang city is relatively much more enclosed than that of Xi'an city. It has been observed that the more enclosed the geological environment of geothermal water is, the more obvious the oxygen shifts are. With the increasing of the depth, residence time, total amounts of thssolute solids and temperatures of geothermal waters, the oxygen exchange accelerates.

  17. Structure of the Anayet Permian basin (Axial Zone, Central Pyrenees)

    Science.gov (United States)

    Rodriguez, L.; Cuevas, J.; Tubía, J. M.

    2012-04-01

    The Anayet Permian basin was generated by strike-slip tectonics that opened subsident basins with pull-apart geometries in the western Spanish Axial Zone (between the Aragon and Tena valleys). A continental succession of Permian age, that represents the first post-variscan deposits in the area, fills the basin and covers discordantly Devonian to Carboniferous limestones, sandstones and slates. Permian deposits have been classically divided in four main detrital groups, with three basic volcanic episodes interbedded (Gisbert, 1984, Bixel, 1987): the Grey Unit (50-120 m, Estefanian to Kungurian) with slates, conglomerates, tobaceous slates, coal and pyroclastic deposits, the Transition Unit (50 m maximum) showing grey and red sandstones and lutites with oolitic limestones intercalated, the Lower Red Unit (250 m) composed of cross-bedded red sandstones and andesitic volcanic rocks at the top, and finally the Upper Red Unit (400 m minimum, top eroded) formed by three fining up megasequences of carbonates, red sandstones and lutites with lacustrine carbonates intercalated and alkali basalts at the top. Increasingly older rocks are found towards the western part of the basin, where its depocenter is located. South-vergent angular folds deform the Permian sedimentary succession. Fold axes are N115 °E-trending, almost horizontal and are characterized by a remarkably constant orientation. Folds exhibit a long limb dipping slightly to the north and a short vertical limb, occasionally reversed. In the Anayet basin four main folds, with a wavelength of 400 m, can be distinguished, two anticlines and two synclines, with minor folds associated. Related to the angular folds an axial plane foliation, E-trending and dipping 40 to 60° to the north, is developed in the lutites. The more competent rocks, conglomerates and breccias, only locally show a spaced fracture cleavage. No main thrusts have been detected in Permian rocks. However, minor scale decollements, usually low angle

  18. Are similar the parasite communities structure of Trachelyopterus coriaceus and Trachelyopterus galeatus (Siluriformes: Auchenipteridae) in the Amazon basin?

    Science.gov (United States)

    Pantoja, Wanderson Michel de Farias; Silva, Lenise Vargas Flores; Tavares-Dias, Marcos

    2016-01-01

    The aim of this study was to compare the parasite communities in two sympatric host populations, Trachelyopterus coriaceus andTrachelyopterus galeatus, which were caught in tributary of the Amazon River in Brazil. All the specimens of T. galeatusand T. coriaceus were infected by one or more parasites, such as Ichthyophthirius multifiliis, Tripartiella tetramerii, Trichodina nobilis, Cosmetocleithrum striatuli, Contracaecumsp., Cystidicoloides sp., Dadaytremoides parauchenipteri and Gorytocephalus spectabilis. Seven species were common to both host fish, and there were 1-5 parasite species per host. In both hosts, trichodinids were dominant. Aggregate dispersion of ectoparasites and endoparasites was observed, with greater aggregation among endoparasites. Only the ectoparasites species showed differences in intensity and/or abundance. However, the parasite communities of the two hosts were taxonomically similar (99%) and characterized by high prevalence and high abundance of ectoparasites, but with low diversity, prevalence and abundance of endoparasites. Trachelyopterus galeatus, the host with the larger body size, presented greater variation of Brillouin diversity and evenness, while T. coriaceus had higher Berger-Parker dominance values and total numbers of parasites. This first study on these parasites ofT. galeatus and T. coriaceus showed that the life mode, size of the hosts and the availability of infective forms of the parasites were the main factors that influenced the parasite communities structure.

  19. Are similar the parasite communities structure of Trachelyopterus coriaceus and Trachelyopterus galeatus (Siluriformes: Auchenipteridae) in the Amazon basin?

    Science.gov (United States)

    Pantoja, Wanderson Michel de Farias; Silva, Lenise Vargas Flores; Tavares-Dias, Marcos

    2016-01-01

    The aim of this study was to compare the parasite communities in two sympatric host populations, Trachelyopterus coriaceus andTrachelyopterus galeatus, which were caught in tributary of the Amazon River in Brazil. All the specimens of T. galeatusand T. coriaceus were infected by one or more parasites, such as Ichthyophthirius multifiliis, Tripartiella tetramerii, Trichodina nobilis, Cosmetocleithrum striatuli, Contracaecumsp., Cystidicoloides sp., Dadaytremoides parauchenipteri and Gorytocephalus spectabilis. Seven species were common to both host fish, and there were 1-5 parasite species per host. In both hosts, trichodinids were dominant. Aggregate dispersion of ectoparasites and endoparasites was observed, with greater aggregation among endoparasites. Only the ectoparasites species showed differences in intensity and/or abundance. However, the parasite communities of the two hosts were taxonomically similar (99%) and characterized by high prevalence and high abundance of ectoparasites, but with low diversity, prevalence and abundance of endoparasites. Trachelyopterus galeatus, the host with the larger body size, presented greater variation of Brillouin diversity and evenness, while T. coriaceus had higher Berger-Parker dominance values and total numbers of parasites. This first study on these parasites ofT. galeatus and T. coriaceus showed that the life mode, size of the hosts and the availability of infective forms of the parasites were the main factors that influenced the parasite communities structure. PMID:27007248

  20. A Metagenomic Perspective on Changes to Nutrient-cycling Genes Following Forest-to-agriculture Conversion in the Amazon Basin

    Science.gov (United States)

    Meyer, K. M.; Womack, A. M.; Rodrigues, J.; Nüsslein, K.; Bohannan, B. J. M.

    2014-12-01

    Forest-to-agriculture conversion has been shown to alter nutrient cycling and the community composition of soil microorganisms. However, few studies have looked simultaneously at how the abundance, composition, and diversity of microbial genes involved in nutrient cycling change with conversion. We used shotgun metagenomic sequencing to analyze soil from primary rainforest and converted cattle pasture sampled at the Fazenda Nova Vida in Rondônia, Brazil. The diversity, richness, and evenness of nutrient cycling genes were significantly higher in the pasture, and the composition of nutrient cycling communities differed significantly between land use types. These results largely mirror taxonomic shifts following Amazon rainforest conversion, which tends to increase diversity, richness, and evenness of soil microbial communities. The abundance of genes related to N cycling and methane flux differed between land use types. Methanotrophy genes decreased in abundance in the pasture, whereas methanogenesis genes were not significantly different between land use types. These changes could underlie the commonly observed shift from methane sink to source following forest-to-agriculture conversion. Multiple genes in the nitrogen cycle also differed with land use, including genes related to N-fixation and ammonification. Metagenomics provides a unique perspective on the consequences of land use change on microbial community structure and function.

  1. Aeromagnetic anomalies uncover the Precambrian basement in the Chhattisgarh basin area, Central India

    Science.gov (United States)

    Ram, Bahadur; Singh, Nagendra; Murthy, A.

    2008-12-01

    This paper presents aeromagnetic images for the Chhattisgarh basin region, in Central India, to provide a new window on Precambrian basement geology and structure. On the basis of aeromagnetic patterns, the Chhattisgarh basin is sub-divided into a northern low (negative) anomaly zone and a southern high (positive) anomaly zone. The northern portion of the main Chhattisgarh basin has been further divided into two subbasins, the Hirri sub-basin in the west, and Baradwar sub-basin in the east. A prominent negative anomaly delineates a NW-SE trending greenstone belt separating these sub-basins. Positive magnetic anomalies delineate the extent of the Dongargarh granite and equivalents, while the weak magnetic anomaly in the southeast of the Dongargarh granite and equivalents reflect granulite gneisses of the Eastern Ghat Mobile Belt. By applying the reduced-to-the-equator filter we enhanced the possible magnetic sources and structural lineaments within the Chhattisgarh basin. A new sketch map of structural elements was then compiled from aeromagnetic interpretation over the Chhattisgarh basin area. It includes possible faults, folds and an inferred lithological boundary.

  2. Slope instability in the Bastardo Basin (Umbria, Central Italy – The landslide of Barattano

    Directory of Open Access Journals (Sweden)

    C. Cencetti

    2003-01-01

    Full Text Available The Bastardo Basin is one of the classics Apenninic intermontane basins of central Italy. They are en-closed tectonic basins (graben and semigraben with high anthropization, but with high vulnerability, too (seismic, hydrogeological and geomorphological. The paper concerns some aspects about slope instability in the Bastardo Basin as part of a wider research, which aims to actually define the characteristics of the liability to landslides of the Apenninic intermontane basins. In particular lithological, stratigraphical and hydrogeological conditions are analysed under which a landslide near village of Barattano has developed. This mass movement, at different times, produced partial or total occlusion of the torrent Puglia. Here geognostic investigations together with laboratory tests and subsequent monitoring of landslide area were carried out.  A back analysis, based on limit equilibrium solutions for the factor of safety of the slope, provided the residual strenght properties of the soil mass along the sliding surface.   The landslide of Barattano is representative of a very frequent situation (in terms of type, factors and causes of the movement, possible development of the movement not only within Bastardo Basin, but in general within Apenninic intermontane basins, too.  The study of landslide and the design of appropriate remedial measures are of great importance in terms of prevention and mitigation of geologic-hydraulic risk in Apenninic intermontane basins.

  3. Macrofaunal diversity in the Central Indian Ocean Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Pavithran, S.; Ingole, B.S.; Nanajkar, M.; Nath, B.N.

    in the dissolved oxygen helps the organic carbon to get oxidized (Nath and Mudholkar 1989). 16 TROPICAL CONSERVANCY conclusIon The abyss of world oceans harbors a diverse community of macrofauna. The current study reported a total of 27 species, with highest... the Council of Scientific and Industrial Research for the fellowship provided for carrying out her Ph.D work. This is NIO contribution number 4303. references Borowski, C. 2001. Physically disturbed deep-sea macrofauna in the Peru Basin, southeast Pacific...

  4. Tectonics and sedimentary evolution of the Sandino forearc basin off Nicaragua, Central America

    Science.gov (United States)

    Costa Pisani, P.; Silver, E.; McIntosh, K.; Ahmed, I.; Ranero, C. R.; Taylor, B.

    2003-04-01

    The Sandino basin is the Nicaragua sector of the Central American forearc, where the Cocos plate subducts beneath the Middle America trench. Recently, Ranero et al. have interpreted a seismic section across the margin and proposed a history of formation of the forearc which is constrained by industry drilling in the basin. They suggested a late Cretaceous to Paleocene accretion event, followed by later subduction erosion processes. The margin wedge consists of the ophiolitic Nicoya complex. The seismic units, unconformities and tectonic features record a rich history of both local and regional vertical movements occurring since the Middle Eocene, which are linked to the evolution of the Pacific convergent margin. During June, 2000, 2800 kms of multichannel seismic reflection data were collected on the R/V Ewing off Nicaragua. Analysis of the 240 channels dataset indicates rapid changes along strike in the Sandino basin. The basin is relatively thin in the southern part, thinning quite rapidly southward against the Nicoya complex of the Santa Elena peninsula of Costa Rica. The forearc sediments thickness approaches and locally exceeds 10 kms in the central and northern parts of the Sandino basin. The oldest units (Upper Cretaceous-Middle Eocene) are very thick off northern Nicaragua, with relatively thin middle to late Cenozoic deposits. However, off central Nicaragua the latter units (Middle-Upper Miocene) attain great thicknesses and the older units appear to thin. This pattern suggests a history of successive deepening of the basin from north to south, after the convergent system evolved from accretion to subduction erosion processes. Present efforts are devoted to quantifying this change in development and using it to understand the dynamics of forearc basin evolution offshore of Central America.

  5. Analysis of tectonic-controlled fluvial morphology and sedimentary processes of the western Amazon Basin: an approach using satellite images and digital elevation model

    Directory of Open Access Journals (Sweden)

    Clauzionor L. Silva

    2007-12-01

    Full Text Available An investigation of the tectonic controls of the fluvial morphology and sedimentary processes of an area located southwest of Manaus in the Amazon Basin was conducted using orbital remote sensing data. In this region, low topographic gradients represent a major obstacle for morphotectonic analysis using conventional methods. The use of remote sensing data can contribute significantly to overcome this limitation. In this instance, remote sensing data comprised digital elevation model (DEM acquired by the Shuttle Radar Topographic Mission (SRTM and Landsat Thematic Mapper images. Advanced image processing techniques were employed for enhancing the topographic textures and providing a three-dimensional visualization, hence allowing interpretation of the morphotectonic elements. This led to the recognition of main tectonic compartments and several morphostructural features and landforms related to the neotectonic evolution of this portion of the Amazon Basin. Features such as fault scarps, anomalous drainage patterns, aligned ridges, spurs and valleys, are expressed in the enhanced images as conspicuous lineaments along NE-SW, NW-SE, E-W and N-S directions. These features are associated to the geometry of alternated horst and graben structures, the latter filled by recent sedimentary units. Morphotectonic interpretation using this approach has proven to be efficient and permitted to recognize new tectonic features that were named Asymmetric Ariaú Graben, Rombohedral Manacapuru Basin and Castanho-Mamori Graben.Uma investigação do controle tectônico da morfologia fluvial e dos processos sedimentares de uma área localizada a sudoeste da cidade de Manaus, na Bacia do Amazonas, foi conduzida a partir do uso de dados de sensores remotos orbitais. Nessa região, o baixo gradiente topográfico representa o principal obstáculo para a análise morfotectônica usando métodos convencionais. O uso de dados de sensores remotos pode contribuir

  6. Amazon flood wave hydraulics

    Science.gov (United States)

    Trigg, Mark A.; Wilson, Matthew D.; Bates, Paul D.; Horritt, Matthew S.; Alsdorf, Douglas E.; Forsberg, Bruce R.; Vega, Maria C.

    2009-07-01

    SummaryA bathymetric survey of 575 km of the central Amazon River and one of its tributaries, the Purus, are combined with gauged data to characterise the Amazon flood wave, and for hydraulic modelling of the main channel for the period June 1995-March 1997 with the LISFLOOD-FP and HEC-RAS hydraulic models. Our investigations show that the Amazon flood wave is subcritical and diffusive in character and, due to shallow bed slopes, backwater conditions control significant reach lengths and are present for low and high water states. Comparison of the different models shows that it is necessary to include at least the diffusion term in any model, and the RMSE error in predicted water elevation at all cross sections introduced by ignoring the acceleration and advection terms is of the order of 0.02-0.03 m. The use of a wide rectangular channel approximation introduces an error of 0.10-0.15 m on the predicted water levels. Reducing the bathymetry to a simple bed slope and with mean cross section only, introduces an error in the order of 0.5 m. These results show that when compared to the mean annual amplitude of the Amazon flood wave of 11-12 m, water levels are relatively insensitive to the bathymetry of the channel model. The implication for remote sensing studies of the central Amazon channel, such as those proposed with the Surface Water and Ocean Topography mission (SWOT), is that even relatively crude assumptions regarding the channel bathymetry will be valid in order to derive discharge from water surface slope of the main channel, as long as the mean channel area is approximately correct.

  7. Availability of water resources in the rio Bermudez micro-basin. Central Region of Costa Rica

    International Nuclear Information System (INIS)

    The Rio Bermudez micro-basin makes up part of the principal hydrological resource area in the Central Region of Costa Rica. For this reason a study was done to determine the availability of hydrological resources in said micro-basin to identify areas with potential water availability problems. A monthly water balance was calculated using land use, geomorphology and climate parameters. From these water balance studies, the amount of available water was calculated and classified into four categories, however, in this micro-basin, only three categories were identified: high, medium and moderate water availability. No areas were identified with low water availability, indicating availability is sufficient; however, there is increasing demand on water resources because over half of the micro-basin area is classified as having moderate water availability. (Author)

  8. Middle Ordovician brachiopods from the Stairway Sandstone, Amadeus Basin, central Australia

    DEFF Research Database (Denmark)

    Jakobsen, Kristian Grube; Brock, Glenn A.; Nielsen, Arne Thorshøj;

    2014-01-01

    Middle Ordovician brachiopod faunas from the Amadeus Basin, central Australia are poorly known. The Darriwilian Stairway Sandstone was sampled stratigraphically for macrofossils in order to provide new information on marine benthic diversity in this clastic-dominated, shallow-water palaeoenvironm......Middle Ordovician brachiopod faunas from the Amadeus Basin, central Australia are poorly known. The Darriwilian Stairway Sandstone was sampled stratigraphically for macrofossils in order to provide new information on marine benthic diversity in this clastic-dominated, shallow......-water palaeoenvironment along the margin of northeastern Gondwana. The brachiopods from the Stairway Sandstone are of low diversity and represent ca 9% of the entire shelly fauna. Five brachiopod taxa are described from the Stairway Sandstone; all are endemic to the Amadeus Basin at species level. Two new species...

  9. Assessing and addressing the re-eutrophication of Lake Erie: central basin hypoxia

    Science.gov (United States)

    Scavia, Donald; Allan, J. David; Arend, Kristin K.; Bartell, Steven; Beletsky, Dmitry; Bosch, Nate S.; Brandt, Stephen B.; Briland, Ruth D.; Daloğlu, Irem; DePinto, Joseph V.; Dolan, David M.; Evans, Mary Anne; Farmer, Troy M.; Goto, Daisuke; Han, Haejin; Höök, Tomas O.; Knight, Roger; Ludsin, Stuart A.; Mason, Doran; Michalak, Anna M.; Richards, R. Peter; Roberts, James J.; Rucinski, Daniel K.; Rutherford, Edward; Schwab, David J.; Sesterhenn, Timothy M.; Zhang, Hongyan; Zhou, Yuntao

    2014-01-01

    Relieving phosphorus loading is a key management tool for controlling Lake Erie eutrophication. During the 1960s and 1970s, increased phosphorus inputs degraded water quality and reduced central basin hypolimnetic oxygen levels which, in turn, eliminated thermal habitat vital to cold-water organisms and contributed to the extirpation of important benthic macroinvertebrate prey species for fishes. In response to load reductions initiated in 1972, Lake Erie responded quickly with reduced water-column phosphorus concentrations, phytoplankton biomass, and bottom-water hypoxia (dissolved oxygen 2) requires cutting total phosphorus loads by 46% from the 2003–2011 average or reducing dissolved reactive phosphorus loads by 78% from the 2005–2011 average. Reductions to these levels are also protective of fish habitat. We provide potential approaches for achieving those new loading targets, and suggest that recent load reduction recommendations focused on western basin cyanobacteria blooms may not be sufficient to reduce central basin hypoxia to 2000 km2.

  10. Some new observations on the intra-plate deformation in the Central Indian Basin (CIB)

    Digital Repository Service at National Institute of Oceanography (India)

    Murthy, K.S.R.; Neprochnov, O.V.; Levchenko, O.V.; Rao, T.C.S.; Milanovsky, V.E.; Lakshminarayana, S.

    Single channel airgun seismic reflection data from equatorial region of the Central Indian Basin (CIB) revealed some new information on the structure and stratigraphy of the deformed blocks in this area. The data from five (N-S and E-W) traverses...

  11. Response of sedimentary nucleic acids to benthic disturbance in the Central Indian Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Fernandes, C.E.G.; DeSouza, M.J.B.D.; Nair, S.; LokaBharathi, P.A.

    Information on the response of nucleic acids (i.e., DNA and RNA) to simulated benthic disturbance was obtained from samples collected from eight sediment cores (0-10 cm) located in the Central Indian Basin (CIB). In general the total sedimentary DNA...

  12. Current structure and kinetic energy of the abyssal waters in the Central Indian Ocean Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Murty, V.S.N.; RameshBabu, V.; Suryanarayana, A.; Beena, B.S.

    Analysis of abyssal currents measured at 7 levels viz., 4, 8, 15, 30, 50, 100 and 500 mab during October 1996-April 1997 at 10 degrees 01'S, 76 degrees E in the Benthic Disturbance Experiment Site (BDES) in the Central Indian Ocean Basin...

  13. Geological evolution, regional perspectives and hydrocarbon potential of the northwest Phu Khanh Basin, offshore Central Vietnam

    DEFF Research Database (Denmark)

    Fyhn, Michael Bryld Wessel; Nielsen, Lars H.; Boldreel, Lars Ole;

    2009-01-01

      Seismic stratigraphic and structural analyses of the northwest Phu Khanh Basin, offshore Central Vietnam, based on 2-D seismic data, indicate that the initial rifting began during the latest Cretaceous? or Palaeogene controlled by left-lateral transtension along the East Vietnam Boundary Fault ...

  14. Deposition of Mn-Cu-Ni-enriched sediments during glacial period in the Central Indian Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Borole, D.V.

    Two siliceous sediment cores collected from the Central Indian Basin have been analysed for organic carbon, biogenic silica, Al, Mn, Ni and Cu content. The concentrations of Mn, Cu and Ni showed one order of magnitude variation (an enrichment by a...

  15. Satellite gravity anomalies and crustal features of the Central Indian Ocean Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, D.G.; Krishna, K.S.; Neprochnov, Y.P.; Grinko, B.N.

    Satellite free-air gravity anomaly contour map at 5 mGal interval, seismic reflection and bathymetric data lead to the identification of deformed crustal structure of the Central Indian Ocean Basin. Twenty-three NE-SW trending deformed crustal...

  16. Ferromanganese nodules and their associated sediments from the Central Indian Ocean Basin: Rare earth element geochemistry

    Digital Repository Service at National Institute of Oceanography (India)

    Pattan, J.N.; Rao, Ch.M.; Migdisov, A.A.; Colley, S.; Higgs, N.C.; Demidenko, L.

    ,whereasinthesedimenttheyarecarriedbyPandMnphases.AsimilarREEfractionationpatternwithmiddleREEenrichmentoverheavyandlightREEinboththenodulesandtheirassociatedsedimentsuggestfractionationisindependentofREEabundanceandtheircarrierphases. Keywordsmanganesenodules,deep-seasediment,REE,Ce-anomalies,fractionation,CentralIndianOceanBasin. Therareearthelement(REE)concentrationrelationshipinferromanganesenodulesandtheirassociatedsedimentsiscomplexandprovidesinformationonthefactorscontrollingtheiruptake(Elder...® eldetal.,1981).TherearediŒerentviewsregardingwhichphasescontroltheabundanceofREEinferromanganesenodulessuchas multiplephases(Elder® eldetal.,1981;Nathetal.,1992a)andsinglephase(Glasbyetal.,1987;PattanandBanakar,1993).REEanalysisofsurfacesedimentsinthe...

  17. Conventional tree height-diameter relationships significantly overestimate aboveground carbon stocks in the Central Congo Basin

    NARCIS (Netherlands)

    Kearsley, E.; Haulleville, de T.; Hufkens, K.; Kidimbu, A.; Toirambe, B.; Baert, G.; Huygens, D.; Kebede, Y.; Defourny, P.; Bogaert, J.; Beeckman, H.; Steppe, K.; Boeckx, P.; Verbeeck, H.

    2013-01-01

    Policies to reduce emissions from deforestation and forest degradation largely depend on accurate estimates of tropical forest carbon stocks. Here we present the first field-based carbon stock data for the Central Congo Basin in Yangambi, Democratic Republic of Congo. We find an average aboveground

  18. Assessment of shale-oil resources of the Central Sumatra Basin, Indonesia, 2015

    Science.gov (United States)

    Schenk, Christopher J.; Charpentier, Ronald R.; Klett, Timothy R.; Tennyson, Marilyn E.; Mercier, Tracey J.; Brownfield, Michael E.; Pitman, Janet K.; Gaswirth, Stephanie B.; Leathers-Miller, Heidi M.

    2015-11-12

    Using a geology-based assessment methodology, the U.S. Geological Survey estimated means of 459 million barrels of shale oil, 275 billion cubic feet of associated gas, and 23 million barrels of natural gas liquids in the Central Sumatra Basin, Indonesia.

  19. AN INTERDISCIPLINARY APPROACH TO RIPARIAN MEADOW CHARACTERIZATION AND PRIORITIZATION, CENTRAL GREAT BASIN

    Science.gov (United States)

    The Great Basin Ecosystem Management Research group has described the hydrological, geophysical, and geomorphic conditions that lead to the formation and maintenance of riparian meadows of central Nevada. Previous work on these systems has focused on understanding a few study mea...

  20. Early Cretaceous decapod Crustacea from the Neuquén Basin, west-central Argentina

    NARCIS (Netherlands)

    Aguirre-Urreta, Maria Beatriz

    2003-01-01

    Marine deposits of the Neuquén Basin of west-central Argentina (southern South America) are richly fossiliferous; its Mesozoic invertebrate faunas, represented mostly by molluscs, have been extensively studied since the nineteenth century. However, Early Cretaceous decapod crustaceans are far less k

  1. Preliminary geotechnical properties of deepsea sediments from the Central Indian Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Khadge, N.H.

    Geotechnical properties of the Plio-Pleistocene sediments from nodule bearing area in the Central Indian Basin have been studied to know shear strength and water content variation with depth. It reveals that surface sediments have low (less than 1 k...

  2. Physical properties of a long sediment core from the central Indian Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Khadge, N.H.

    In a 7.5 m-long box core, collected at 9 degrees S and 77 degrees E from 5400 m water depth from the Central Indian Basin, geotechnical properties clearly reflect the Plio-Pleistocene boundary. It is marked by a drastic change in the physical...

  3. Comparison of internal features and microchemistry of ferromanganese crusts from the Central Indian Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Iyer, S.D.

    SEM/probe analyses of two ferromanganese crusts from the Central Indian Basin, formed on basalt substrate, reveal botryoids and cusps. The botryoids composed of delta-MnOs2, are enriched in Co, and the cusps and laminations with todorokite...

  4. Exploration inputs for exploitation of manganese nodules in Central Indian Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Sharma, R.; Nair, R.R.

    Large reserves of manganese nodules have been indentified in the Central Indian Basin, as a result of extensive exploration comprising more than 2000 shipdays, 7 research vessels, 9000 samples, 400,000 km of narrowbeam echosounding, 300,000 sq km...

  5. Regional variability in occurrence and distribution of polymetallic nodules in the central Indian Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Valsangkar, A.B.; Rebello, J.M.S.

    Regional scale morphological studies on different-sized polymetallic nodules from the Central Indian Basin show that only 2–5 cm sized nodules have highest occurrence per station (92–94% along latitudes; 88–94% along longitudes). A nodule size shows...

  6. Seasonal variability in the vertical current structure and kinetic energy in the Central Indian Ocean Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Murty, V.S.N.; Savin, M.; RameshBabu, V.; Suryanarayana, A.

    Seasonal variability in the currents at the subsurface (450-670 m), intermediate (1150-1370 m), deeper (3450-3670 m) and near-bottom (4270-5100 m) depths at three mooring station in the Central Indian Ocean Basin (CIOB) were documented in 1995...

  7. Methanol and isoprene emissions from the fast growing tropical pioneer species Vismia guianensis (Aubl.) Pers. (Hypericaceae) in the central Amazon forest

    Science.gov (United States)

    Jardine, Kolby J.; Jardine, Angela B.; Souza, Vinicius F.; Carneiro, Vilany; Ceron, Joao V.; Gimenez, Bruno O.; Soares, Cilene P.; Durgante, Flavia M.; Higuchi, Niro; Manzi, Antonio O.; Gonçalves, José F. C.; Garcia, Sabrina; Martin, Scot T.; Zorzanelli, Raquel F.; Piva, Luani R.; Chambers, Jeff Q.

    2016-05-01

    Isoprene (Is) emissions by plants represent a loss of carbon and energy resources leading to the initial hypothesis that fast growing pioneer species in secondary tropical forests allocate carbon primarily to growth at the expense of isoprenoid defenses. In this study, we quantified leaf isoprene and methanol emissions from the abundant pantropical pioneer tree species Vismia guianensis and ambient isoprene concentrations above a diverse secondary forest in the central Amazon. As photosynthetically active radiation (PAR) was varied (0 to 3000 µmol m-2 s-1) under standard leaf temperature (30 °C), isoprene emissions from V. guianensis increased without saturation up to 80 nmol m-2 s-1. A nonlinear increase in isoprene emissions with respect to net photosynthesis (Pn) resulted in the fraction of Pn dedicated to isoprene emissions increasing with light intensity (up to 2 % of Pn). Emission responses to temperature under standard light conditions (PAR of 1000 µmol m-2 s-1) resulted in the classic uncoupling of isoprene emissions (Topt, iso > 40 °C) from net photosynthesis (Topt, Pn = 30.0-32.5 °C) with up to 7 % of Pn emitted as isoprene at 40 °C. Under standard environmental conditions of PAR and leaf temperature, young V. guianensis leaves showed high methanol emissions, low Pn, and low isoprene emissions. In contrast, mature leaves showed high Pn, high isoprene emissions, and low methanol emissions, highlighting the differential control of leaf phenology over methanol and isoprene emissions. High daytime ambient isoprene concentrations (11 ppbv) were observed above a secondary Amazon rainforest, suggesting that isoprene emissions are common among neotropical pioneer species. The results are not consistent with the initial hypothesis and support a functional role of methanol during leaf expansion and the establishment of photosynthetic machinery and a protective role of isoprene for photosynthesis during high temperature extremes regularly experienced in

  8. Edaphic, structural and physiological contrasts across Amazon Basin forest-savanna ecotones suggest a role for potassium as a key modulator of tropical woody vegetation structure and function

    Science.gov (United States)

    Lloyd, J.; Domingues, T. F.; Schrodt, F.; Ishida, F. Y.; Feldpausch, T. R.; Saiz, G.; Quesada, C. A.; Schwarz, M.; Torello-Raventos, M.; Gilpin, M.; Marimon, B. S.; Marimon-Junior, B. H.; Ratter, J. A.; Grace, J.; Nardoto, G. B.; Veenendaal, E.; Arroyo, L.; Villarroel, D.; Killeen, T. J.; Steininger, M.; Phillips, O. L.

    2015-11-01

    Sampling along a precipitation gradient in tropical South America extending from ca. 0.8 to 2.0 m a-1, savanna soils had consistently lower exchangeable cation concentrations and higher C / N ratios than nearby forest plots. These soil differences were also reflected in canopy averaged leaf traits with savanna trees typically having higher leaf mass per unit area but lower mass-based nitrogen (Nm) and potassium (Km). Both Nm and Km also increased with declining mean annual precipitation (PA), but most area-based leaf traits such as leaf photosynthetic capacity showed no systematic variation with PA or vegetation type. Despite this invariance, when taken in conjunction with other measures such as mean canopy height, area-based soil exchangeable potassium content, [K]sa , proved to be an excellent predictor of several photosynthetic properties (including 13C isotope discrimination). Moreover, when considered in a multivariate context with PA and soil plant available water storage capacity (θP) as covariates, [K]sa also proved to be an excellent predictor of stand-level canopy area, providing drastically improved fits as compared to models considering just PA and/or θP. Neither calcium, nor magnesium, nor soil pH could substitute for potassium when tested as alternative model predictors (ΔAIC > 10). Nor for any model could simple soil texture metrics such as sand or clay content substitute for either [K]sa or θP. Taken in conjunction with recent work in Africa and the forests of the Amazon Basin, this suggests - in combination with some newly conceptualised interacting effects of PA and θP also presented here - a critical role for potassium as a modulator of tropical vegetation structure and function.

  9. Optical and physical properties of aerosols in the boundary layer and free troposphere over the Amazon Basin during the biomass burning season

    Directory of Open Access Journals (Sweden)

    D. Chand

    2006-01-01

    Full Text Available As part of the Large Scale Biosphere-Atmosphere Experiment in Amazonia – Smoke, Aerosols, Clouds, Rainfall and Climate (LBA-SMOCC campaign, detailed surface and airborne aerosol measurements were performed over the Amazon Basin during the dry to wet season from 16 September to 14 November 2002. Optical and physical properties of aerosols at the surface, and in the boundary layer (BL and free troposphere (FT during the dry season are discussed in this article. Carbon monoxide (CO is used as a tracer for biomass burning emissions. At the surface, good correlation among the light scattering coefficient (σs at 545 nm, PM2.5, and CO indicates that biomass burning is the main source of aerosols. Accumulation of haze during some of the large-scale biomass burning events led to high PM2.5 (225 μg m−3, σs (1435 Mm−1, aerosol optical depth at 500 nm (3.0, and CO (3000 ppb. A few rainy episodes reduced the PM2.5, number concentration (CN and CO concentration by two orders of magnitude. The correlation analysis between σs and aerosol optical thickness shows that most of the optically active aerosols are confined to a layer with a scale height of 1617 m during the burning season. This is confirmed by aircraft profiles. The average mass scattering and absorption efficiencies (545 nm for small particles (diameter Dp2 g−1, respectively, when relating the aerosol optical properties to PM2.5 aerosols. The observed mean single scattering albedo (ωo at 545 nm for submicron aerosols at the surface is 0.92±0.02. The light scattering by particles (Δσs/Δ CN increase 2–10 times from the surface to the FT, most probably due to the combined affects of coagulation and condensation.

  10. The fate of nitrogen fertilizer added to soy-maize agriculture in the Amazon basin: Quantifying N2O flux and losses to groundwater

    Science.gov (United States)

    Jankowski, K. J.; Neill, C.; Davidson, E. A.; Macedo, M.; Costa, C., Jr.; Galford, G. L.; Coe, M. T.; O'Connell, C.; Brando, P. M.; Lefebvre, P.; Maracahipes, L.; Nunes, D.; McHorney, R.

    2015-12-01

    Deforestation and agricultural intensification are rapidly changing the landscape of southeastern Amazonia. With international pressure to reduce deforestation, many Brazilian farms have opted to intensify agriculture to a system of soybean-maize double cropping, and it has expanded rapidly in the last 10 years. Maize agriculture requires additional nitrogen (N) fertilizers, whose downstream fate is currently unknown. Typical fertilizer application rates range from 30-120 kg N ha-1, and have the potential to introduce large amounts of N to ecosystems of the Amazon basin, which can alter greenhouse gas flux and nutrient transport to groundwater and streams. Little data on the fate of added fertilizers are available in the tropics in general, especially in this critical region of agricultural expansion. Therefore, we established a field-scale experiment to evaluate the fate of N fertilizer on Tanguro Ranch in Mato Grosso, Brazil, a region of rapidly expanding soy-maize double cropping. We measured greenhouse gas fluxes (N2O, CO2, and CH4), soil N content, losses to groundwater, and corn productivity across five levels of fertilizer addition (0-200 kg N ha-1) throughout an entire growing season. We found that N2O flux increased with fertilizer addition, but was only significantly higher at 200 kg N ha-1. Surface soil N content increased after fertilizer addition, but decreased within weeks, and was quickly observed in subsurface soil water. Modeling results that scale these findings to the state of Mato Grosso suggest that this land use transition could create a substantial new source of N2O and CO2 to the atmosphere and has the potential to leach N fertilizer into groundwater and downstream. It is important to maintain forest code policies that minimize these impacts.

  11. Post-partum reproductive efficiency of pure- and cross-bred Zebu cattle under different management and nutritional conditions in the Amazon Basin of Peru

    International Nuclear Information System (INIS)

    The experiments described were carried out by the Research Centre of the Veterinary Institute for Tropical and High Altitude Research (IVITA), at an experimental station located near Pucallpa in the Amazon Basin of Peru. The aim was to study some of the factors affecting reproductive efficiency under field conditions, with special emphasis on the effects of nutrition, body weight, suckling and some adaptation related parameters in pure- and cross-bred Zebu cattle. Progesterone assay was used in combination with clinical examinations to evaluate more precisely the reproductive parameters studied. A long post-partum anoestrus interval was the most important factor limiting reproductive efficiency in pure-bred Zebu animals. The 10 month interval observed under field and experimental conditions was shortened by improving the level of nutrition. However, the first ovulation after parturition was inhibited by free or restricted suckling until weaning took place 8 months post-partum. In contrast, dual purpose cross bred Bos taurus x Bos indicus animals tended to show better reproductive performance when suckling was allowed, the difference being significant when adequate management and feeding were also provided. Body weight at calving and subsequent weight changes during the post-partum period significantly affected the onset of post-partum reproductive function in both pure- and cross-bred Zebu cows. Cross-bred animals with a low body weight at calving remained acyclic for 8 months. On small farms, only 35% of the intervals between artificial insemination services were in the range of 18 to 24 days. Progesterone profiles determined between successive oestrous periods revealed a high frequency of unobserved oestrus. The correlation between rectal palpation of ovarian structures and progesterone concentration was 0.82 and 0.96 in diagnosing luteal and non-luteal structures respectively. The combination of weekly clinical examinations and progesterone determinations gave a

  12. The optical properties of river and floodplain waters in the Amazon River Basin: Implications for satellite-based measurements of suspended particulate matter

    Science.gov (United States)

    Martinez, Jean-Michel; Espinoza-Villar, Raul; Armijos, Elisa; Silva Moreira, Luciane

    2015-07-01

    Satellite images can now be used to assess river sediment discharge, and systematic studies over rivers and lakes are required to support such applications and document the variability of inland water optical properties at the watershed scale. The optical properties of the Amazon Basin waters were analyzed from in situ measurements of the remote sensing reflectance (Rrs) at 279 stations and downwelling diffuse attenuation coefficients (Kd) at 133 stations. Measurements of the apparent optical properties, suspended particulate matter (SPM) contents, and characteristics and colored dissolved organic matter (CDOM) absorption spectra were performed during 16 cruises along the main Amazonian Rivers draining the Andes and for some tributaries. Surface-suspended sediment granulometry and mineralogy showed a stable distribution at the catchment scale, even over large distances and between tributaries. The particle number-size distribution was best described using a segmented distribution with a slope of 2.2 for the fine range (1-15 µm), and the CDOM absorption coefficient at 440 nm varied from 1.8 to 7.9 m-1. Overall, both Rrs and Kd were strongly correlated with SPM, although strong CDOM absorption limited the use of the blue spectrum. Reflectance saturation from blue to red was observed at approximately 100 g m-3, whereas the near-infrared (NIR) wavelength enabled the monitoring of the full SPM range (5-620 g m-3). In contrast, Kd showed no saturation for SPM from green to NIR, and a linear model was calculated. The use of the reflectance ratio was investigated and shown to improve the suspended sediment concentration retrieval performance.

  13. Adolescent pregnancies and girls' sexual and reproductive rights in the amazon basin of Ecuador: an analysis of providers' and policy makers' discourses

    Directory of Open Access Journals (Sweden)

    Sebastian Miguel

    2010-06-01

    Full Text Available Abstract Background Adolescent pregnancies are a common phenomenon that can have both positive and negative consequences. The rights framework allows us to explore adolescent pregnancies not just as isolated events, but in relation to girls' sexual and reproductive freedom and their entitlement to a system of health protection that includes both health services and the so called social determinants of health. The aim of this study was to explore policy makers' and service providers' discourses concerning adolescent pregnancies, and discuss the consequences that those discourses have for the exercise of girls' sexual and reproductive rights' in the province of Orellana, located in the amazon basin of Ecuador. Methods We held six focus-group discussions and eleven in-depth interviews with 41 Orellana's service providers and policy makers. Interviews were transcribed and analyzed using discourse analysis, specifically looking for interpretative repertoires. Results Four interpretative repertoires emerged from the interviews. The first repertoire identified was "sex is not for fun" and reflected a moralistic construction of girls' sexual and reproductive health that emphasized abstinence, and sent contradictory messages regarding contraceptive use. The second repertoire -"gendered sexuality and parenthood"-constructed women as sexually uninterested and responsible mothers, while men were constructed as sexually driven and unreliable. The third repertoire was "professionalizing adolescent pregnancies" and lead to patronizing attitudes towards adolescents and disregard of the importance of non-medical expertise. The final repertoire -"idealization of traditional family"-constructed family as the proper space for the raising of adolescents while at the same time acknowledging that sexual abuse and violence within families was common. Conclusions Providers' and policy makers' repertoires determined the areas that the array of sexual and reproductive

  14. Edaphic, structural and physiological contrasts across Amazon Basin forest–savanna ecotones suggest a role for potassium as a key modulator of tropical woody vegetation structure and function

    Directory of Open Access Journals (Sweden)

    J. Lloyd

    2015-11-01

    C / N ratios than nearby forest plots. These soil differences were also reflected in canopy averaged leaf traits with savanna trees typically having higher leaf mass per unit area but lower mass-based nitrogen (Nm and potassium (Km. Both Nm and Km also increased with declining mean annual precipitation (PA, but most area-based leaf traits such as leaf photosynthetic capacity showed no systematic variation with PA or vegetation type. Despite this invariance, when taken in conjunction with other measures such as mean canopy height, area-based soil exchangeable potassium content, [K]sa , proved to be an excellent predictor of several photosynthetic properties (including 13C isotope discrimination. Moreover, when considered in a multivariate context with PA and soil plant available water storage capacity (θP as covariates, [K]sa also proved to be an excellent predictor of stand-level canopy area, providing drastically improved fits as compared to models considering just PA and/or θP. Neither calcium, nor magnesium, nor soil pH could substitute for potassium when tested as alternative model predictors (ΔAIC > 10. Nor for any model could simple soil texture metrics such as sand or clay content substitute for either [K]sa or θP. Taken in conjunction with recent work in Africa and the forests of the Amazon Basin, this suggests – in combination with some newly conceptualised interacting effects of PA and θP also presented here – a critical role for potassium as a modulator of tropical vegetation structure and function.

  15. Edaphic, structural and physiological contrasts across Amazon Basin forest-savanna ecotones suggest a role for potassium as a key modulator of tropical woody vegetation structure and function

    Directory of Open Access Journals (Sweden)

    J. Lloyd

    2015-05-01

    C/N ratios than nearby forest plots. These soil differences were also reflected in canopy averaged leaf traits with savanna trees typically having higher leaf mass per unit area but lower mass-based nitrogen (Nm and potassium (Km. Both Nm and Km also increased with declining mean annual precipitation (PA, but most area-based leaf traits such as leaf photosynthetic capacity showed no systematic variation with PA or vegetation type. Despite this invariance, when taken in conjunction with other measures such mean canopy height, area-based soil exchangeable potassium content, [K]sa, proved to be an excellent predictor of several photosynthetic properties (including 13C isotope discrimination. Moreover, when considered in a multivariate context with PA and soil plant available water storage capacity (θP as covariates, [K]sa also proved to be an excellent predictor of stand-level canopy area, providing drastically improved fits as compared to models considering just PA and/or θP. Neither calcium, magnesium nor soil pH could substitute for potassium when tested as alternative model predictors (ΔAIC > 10. Nor for any model could simple soil texture metrics such as sand or clay content substitute for either [K]sa or θP. Taken in conjunction with recent work in Africa and the forests of the Amazon Basin this suggests – in combination with some newly conceptualised interacting effects of PA and θP also presented here – a critical role for potassium as a modulator of tropical vegetation structure and function.

  16. Morphometric characterization of sub-basins in the municipality of Xapuri: subsidies to land management in the Western Amazon

    Directory of Open Access Journals (Sweden)

    Éllen Albuquerque Abud

    2015-04-01

    Full Text Available This work morphometrically characterized watersheds that occur in the municipality of Xapuri and constructed a model that explains the extent of watershed impact and resilience. Emphasis was given to provide a decision-making tool for non-specialists. The study area is located in the State of Acre and has four sub-basins: Alto Acre, Rio Xapuri, Xipamanu and Riozinho do Rola. A cartographic survey was conducted, to include the morphometric characteristics of the area and land use and cover features that resulted in the soil-hydrographic zoning of the municipality. Sub-basins Xapuri, Xipamanu and Riozinho do Rôla revealed drainage densities and orders that indicate low drainage efficiency, while Alto Acre presented high drainage orders (ninth order and densities, contrary the geometric indices and drainage densities, and is considered to have efficient drainage. Considerable alterations in permanent preservation areas occur in the municipality of Xapuri, with conversion to less resilient areas highly sensitive to impacts. The soil-hydrographic zoning assists in visualizing the municipality in a land management context through an ecosystem approach and a qualitative view of the possibilities and weaknesses.

  17. Petroleum source rocks of western and central Africa : the examples of the marine Tarfaya Basin, Morocco and the continental Congo Basin, Democratic Republic of Congo

    OpenAIRE

    Sachse, Victoria Frederike

    2011-01-01

    This study comprises newly collected organic geochemical and petrological data on quality, quantity, maturity as well as the depositional environment of various organic matter-rich stratigraphic units in Morocco and the Central Congo Basin, DRC. In addition, 1D modeling was carried out for one locality in northern Morocco (Aït Moussa) and for two wells from the Central Congo Basin to obtain information on burial thermal and maturation history. For the Aït Moussa model, specific bulk kinetic p...

  18. Implementation of basic quality control tests for malaria medicines in Amazon Basin countries: results for the 2005–2010 period

    Directory of Open Access Journals (Sweden)

    Pribluda Victor S

    2012-06-01

    Full Text Available Abstract Background Ensuring the quality of malaria medicines is crucial in working toward malaria control and eventual elimination. Unlike other validated tests that can assess all critical quality attributes, which is the standard for determining the quality of medicines, basic tests are significantly less expensive, faster, and require less skilled labour; yet, these tests provide reproducible data and information on several critical quality attributes, such as identity, purity, content, and disintegration. Visual and physical inspection also provides valuable information about the manufacturing and the labelling of medicines, and in many cases this inspection is sufficient to detect counterfeit medicines. The Promoting the Quality of Medicines (PQM programme has provided technical assistance to Amazon Malaria Initiative (AMI countries to implement the use of basic tests as a key screening mechanism to assess the quality of malaria medicines available to patients in decentralized regions. Methods Trained personnel from the National Malaria Control Programmes (NMCPs, often in collaboration with country’s Official Medicine Control Laboratory (OMCL, developed country- specific protocols that encompassed sampling methods, sample analysis, and data reporting. Sampling sites were selected based on malaria burden, accessibility, and geographical location. Convenience sampling was performed and countries were recommended to store the sampled medicines under conditions that did not compromise their quality. Basic analytical tests, such as disintegration and thin layer chromatography (TLC, were performed utilizing a portable mini-laboratory. Results Results were originally presented at regional meetings in a non-standardized format that lacked relevant medicines information. However, since 2008 information has been submitted utilizing a template specifically developed by PQM for that purpose. From 2005 to 2010, the quality of 1,663 malaria medicines

  19. Reconsidering the taxonomy of the Black-Faced Uacaris, Cacajao melanocephalus group (Mammalia: Pitheciidae), from the northern Amazon Basin.

    Science.gov (United States)

    Ferrari, Stephen F; Guedes, Patrícia G; Figueiredo-Ready, Wilsea M B; Barnett, Adrian A

    2014-09-24

    The black-faced uacaris are a poorly known group of platyrrhine monkeys from the Rio Negro basin in northwestern Amazonia. Originally described as two distinct species-Cacajao melanocephalus (Humboldt 1812) and Cacajao ouakary (Spix 1823)-from opposite banks of the Negro, they were treated as a single species until the end of the twentieth century, when molecular studies reconfirmed their status as true species. One of these studies not only nominated a third (northern) species, Cacajao ayresi Boubli et al. 2008, but also identified C. ouakary as a junior synonym of C. melanocephalus, resulting in the introduction of a new nomen, Cacajao hosomi Boubli et al. 2008. In the present study, additional evidence on morphological and zoogeographic variables is analyzed, which indicates that C. ouakary should be reinstated, and supports the nomination of a neotype of C. melanocephalus. The molecular and zoogeographic data on the species status of the ayresi form are also re-assessed, leading to the conclusion that, on the basis of the evidence available at the present time, this form should be considered a subspecies of C. melanocephalus. A new taxonomic arrangement is proposed, which recognizes two species, C. ouakary and C. melanocephalus, the latter with two subspecies, C. m. melanocephalus and C. m. ayresi.

  20. Dinâmica populacional da matrinxã Brycon amazonicus (Characidae na Amazônia Central Population dynamics of matrinxã Brycon amazonicus (Characidae in Central Amazon

    Directory of Open Access Journals (Sweden)

    Leocy C. dos Santos Filho

    2009-06-01

    Full Text Available The matrinxã, Brycon amazonicus (Spix & Agassiz, 1829 is one of the most important fishery resources of the Amazonas state. Its population dynamics in Central Amazon was analyzed based on total landing and biometry data registered in the main landing port of Manaus, between 1994 and 2002. Growth and mortality rates were estimated separately for the rivers Purus, Madeira and Solimões. Differences in size structure and growth curves suggest that different population units exist among these rivers, requiring individualized evaluation and fisheries management strategies. The analysis of the yield per recruit does not indicate overexploitation. However, the highest relative exploitation rate was observed in the Madeira river. The suggested management strategies are related to restrictions to the fishery in the main fishing grounds during the migratory dispersal period, instead of restrictions during reproductive periods.

  1. Overview of the structural geology and tectonics of the Central Basin Platform, Delaware Basin, and Midland Basin, West Texas and New Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Hoak, T. [Kestrel Geoscience, Littleton, CO (United States); Sundberg, K. [Phillips Petroleum Co., Bartlesville, OK (United States); Ortoleva, P. [Indiana Univ., Bloomington, IN (United States)

    1998-12-31

    The structural geology and tectonics of the Permian Basin were investigated using an integrated approach incorporating satellite imagery, aeromagnetics, gravity, seismic, regional subsurface mapping and published literature. The two primary emphases were on: (1) delineating the temporal and spatial evolution of the regional stress state; and (2) calculating the amount of regional shortening or contraction. Secondary objectives included delineation of basement and shallower fault zones, identification of structural style, characterization of fractured zones, analysis of surficial linear features on satellite imagery and their correlation to deeper structures. Gandu Unit, also known as Andector Field at the Ellenburger level and Goldsmith Field at Permian and younger reservoir horizons, is the primary area of interest and lies in the northern part of Ector county. The field trends northwest across the county line into Andrews County. The field(s) are located along an Ellenburger thrust anticline trap on the eastern margin of the Central Basin Platform.

  2. Recharge sources and hydrogeochemical evolution of groundwater in alluvial basins in arid central Australia

    Science.gov (United States)

    Vanderzalm, J. L.; Jeuken, B. M.; Wischusen, J. D. H.; Pavelic, P.; Le Gal La Salle, C.; Knapton, A.; Dillon, P. J.

    2011-01-01

    SummaryIt is necessary to define the role of various sources of recharge in the surficial alluvial aquifer system in arid Alice Springs in central Australia, for future management of water resources in the region. Multiple sources of natural recharge include infiltration from ephemeral stream flow in the Todd River; groundwater throughflow between connected alluvial basins; regional groundwater flow from the underlying Tertiary aquifer; and diffuse recharge. In addition treatment, storage and irrigation reuse of Alice Springs' waste water has resulted in additional recharge of effluent, via infiltration. Water resource management plans for the region include effluent reuse through Soil Aquifer Treatment (SAT) within one of the connected alluvial basins, with the purpose of managing the excess waste water overflows while also supplementing groundwater resources for irrigation and protecting their quality. Hydrogeochemical tracers, chloride and the stable isotopes of water, were used in a three-member mixing model to define and quantify the major recharge sources. The mixing model was not sensitive enough to quantify minor contributions from effluent in groundwater that were identified only by an evaporated isotopic signature. The contribution of the multiple recharge sources varied spatially with proximity to the recharge source; with Todd River, effluent and Town Basin throughflow contributing to the Inner Farm Basin groundwater. The Outer Farm Basin was largely influenced by the Todd River, the Inner Farm Basin throughflow and the older Tertiary aquifer. While Inner Farm groundwater throughflow contains an effluent component, only Outer Farm Basin groundwater near the interface between the two basins clearly illustrated an effluent signature. Aside from this, effluent recharge was not evident in the Outer Farm Basin, indicating that past unmanaged recharge practices will not mask signs of Managed Aquifer Recharge through the Soil Aquifer Treatment (SAT) operation

  3. Neutrons, radiation and archaeology: a multi analytical case study of incised rim tradition ceramics in Central Amazon; Neutrons, radiacao e arqueologia: estudo de caso multianalitico de ceramicas da tradicao borda incisa na Amazonia Central

    Energy Technology Data Exchange (ETDEWEB)

    Hazenfratz-Marks, Roberto

    2014-07-01

    This thesis is an interdisciplinary archaeometric study involving archaeological ceramic material from two large archaeological sites in Central Amazon, namely Lago Grande and Osvaldo, on the confluence region of Negro and Solimoes rivers. It was tested a hypothesis about the existence of an exchange network between the former inhabitants of those sites, focusing on material and/or technological exchange. That hypothesis has implications for archaeological theories of human occupation of the pre-colonial Central Amazon, which try to relativise the role of ecological difficulties of the tropical forest as a limiting factor for the emergence of social complexity in the region. The physical-chemical characterization of potsherds and clay samples near the sites was carried out by: instrumental neutron activation analysis (INAA) to determine the elemental chemical composition; electron paramagnetic resonance (EPR) to determine the firing temperature; X-ray diffraction (XRD) to determine the mineralogical composition; and dating by optically stimulated luminescence (OSL). Previous studies showed that Osvaldo and Lago Grande were occupied by people which produced pottery classified in the Manacapuru and Paredao phases, subclasses of the Incised Rim Tradition, around the 5-10th and 7-12th centuries BC, respectively. INAA results were analyzed by multivariate statistical methods, whereby two chemical groups of pottery were defined for each archaeological site. Significant variation in firing temperatures and mineralogical composition were not identified for such groups. By integration of the results with archaeological data, the superposition between pairs of chemical groups was interpreted as a correlate of an ancient exchange network, although it was not possible to define if it existed exclusively between Lago Grande and Osvaldo. On the contrary, it was suggested that Lago Grande participated in a more extensive exchange network by comparison of two chemical groups

  4. Age and paleoenvironmental reconstruction of partially remagnetized lacustrine sedimentary rocks (Oligocene Aktoprak basin, central Anatolia, Turkey)

    Science.gov (United States)

    Meijers, Maud J. M.; Strauss, Becky E.; Özkaptan, Murat; Feinberg, Joshua M.; Mulch, Andreas; Whitney, Donna L.; Kaymakçı, Nuretdin

    2016-03-01

    The age and paleoenvironmental record of lacustrine deposits in the Aktoprak basin of south-central Turkey provides information about the evolution of topography, including the timing of development of an orographic rain shadow caused by uplift of the mountain ranges fringing the Central Anatolian Plateau. New magnetostratigraphy-based age estimates, in combination with existing biostratigraphic ages, suggest that the partially remagnetized Kurtulmuş Tepe section of the basin is Chattian (Upper Oligocene). The mean carbon and oxygen stable isotope ratios (δ18O= 24.6 ± 2.0 ‰, δ13C= -4.9 ± 1.1‰) are largely constant through the section and indicative of a subtropical, open freshwater lake. These isotopic values are also similar to those of the Chattian Mut basin to the south, on the Mediterranean side of the modern orographic barrier (Tauride Mountains), and indicate absence of an orographic barrier during Late Oligocene basin deposition. Post-depositional partial remagnetization occurred after tilting of the basin sequence and was mineralogically controlled, affecting grey, carbonate-rich rocks (average %CaCO3= 82), whereas interlayered pink carbonate-poor rocks (average %CaCO3= 38) carry a primary, pretilt magnetization. The pink rocks are rich in clay minerals that may have reduced the permeability of these rocks that carry a primary magnetization, concentrating basinal fluid flow in the carbonate-rich grey layers and leading to the removal and reprecipitation of magnetic minerals. The normal and reverse polarities recorded by the remagnetized rocks suggest that remagnetization occurred over a protracted period of time.

  5. Tectono-climatic implications of Eocene Paratethys regression in the Tajik basin of central Asia

    Science.gov (United States)

    Carrapa, Barbara; DeCelles, Peter G.; Wang, Xin; Clementz, Mark T.; Mancin, Nicoletta; Stoica, Marius; Kraatz, Brian; Meng, Jin; Abdulov, Sherzod; Chen, Fahu

    2015-08-01

    Plate tectonics and eustatic sea-level changes have fundamental effects on paleoenvironmental conditions and bio-ecological changes. The Paratethys Sea was a large marine seaway that connected the Mediterranean Neotethys Ocean with Central Asia during early Cenozoic time. Withdrawal of the Paratethys from central Asia impacted the distribution and composition of terrestrial faunas in the region and has been largely associated with changes in global sea level and climate such as cooling associated with the Eocene/Oligocene transition (EOT). Whereas the regression has been dated in the Tarim basin (China), the pattern and timing of regression in the Tajik basin, 400 km to the west, remain unresolved, precluding a test of current paleogeographic models. Here we date the Paratethys regression in Tajikistan at ca. 39 million years ago (Ma), which is several million years older than the EOT (at ca. 34 Ma) marking the greenhouse to icehouse climate transition of the Cenozoic. Our data also show a restricted, evaporitic marine environment since the middle-late Eocene and establishment of desert like environments after ca. 39 Ma. The overall stratigraphic record from the Tajik basin and southern Tien Shan points to deposition in a foreland basin setting by ca. 40 Ma in response to active tectonic growth of the Pamir-Tibet Mountains at the same time. Combined with the northwestward younging trend of the regression in the region, the Tajik basin record is consistent with northward growth of the Pamir and suggests significant tectonic control on Paratethys regression and paleoenvironmental changes in Central Asia.

  6. Seed size influence on germination responses to light and temperature of seven pioneer tree species from the Central Amazon

    Directory of Open Access Journals (Sweden)

    Fabiana F. Aud

    2012-09-01

    Full Text Available In Amazon secondary forests are dominated by pioneer species that typically produce large amounts of small and dormant seeds that are able to form a persistent soil seed bank. Seed dormancy in this group of species is overcome by environmental conditions found in open areas, such as high irradiation or alternating temperatures. Nevertheless, a variety of germination responses to environmental factors is known among pioneers; some of them may germinate in diffuse light or in darkness condition at constant temperature. Seed mass can be considered as one of the factors that promotes this variety. Regarding species with very small seeds, it seems that the trigger for germination is light and for larger seeds temperature alternation may be a more important stimulus. In this study we established a relationship between seed mass and germination response to light and alternating temperature for a group of seven woody pioneer species from the Amazon forest. We found that an increase in seed mass was followed by a decrease in the need for light and an increase in the tolerance to alternating temperatures. Understanding germination strategies may contribute with the knowledge of species coexistence in high diverse environments and also may assist those involved in forest management and restoration.Na Amazônia as florestas secundárias são dominadas por espécies pioneiras que, normalmente, produzem grandes quantidades de sementes pequenas, dormentes e capazes de formar bancos de sementes no solo. A dormência neste grupo de espécies é superada pelas condições ambientais de áreas abertas, como alta irradiação ou alternância de temperaturas. No entanto, uma variedade de respostas de germinação aos fatores ambientais é conhecida entre as pioneiras; algumas germinam em luz difusa ou no escuro sob temperatura constante. Um dos fatores promotores desta variedade é a massa das sementes. Parece que para as espécies com sementes muito pequenas, o est

  7. Methane emissions from northern Amazon savanna wetlands and Balbina Reservoir

    Science.gov (United States)

    Kemenes, A.; Belger, L.; Forsberg, B.; Melack, J. M.

    2006-12-01

    To improve estimates of methane emission for the Amazon basin requires information from aquatic environments not represented in the central basin near the Solimoes River, where most of the current data were obtained. We have combined intensive, year-long measurements of methane emission and water levels made in interfluvial wetlands located in the upper Negro basin with calculations of inundation based on a time series of Radarsat synthetic aperature radar images. These grass-dominated savannas emitted methane at an average rate of 18 mg C per m squared per day, a low rate compared to the habitats with floating grasses the occur in the Solimoes floodplains. Reservoirs constructed in the Amazon typically flood forested landscapes and lead to conditions conducive for methane production. The methane is released to the atmosphere from the reservoir and as the water exits the turbines and from the downstream river. Balbina Reservoir near Manaus covers about 2400 km squared along the Uatuma River. Annual averages of measurements of methane emission from the various habitats in the reservoir range from 23 to 64 mg C per m squared per day. Total annual emission from the reservoir is about 58 Gg C. In addition, about 39 Gg C per year are released below the dam, about 50 percent of which is released as the water passes through the turbines. On an annual areal basis, Balbina Reservoir emits 40 Mg C km squared, in contrast to 30 Mg km squared for the Solimoes mainstem floodplain

  8. 137Cs vertical distribution at the deep basins of the North and Central Aegean Sea, Greece

    International Nuclear Information System (INIS)

    Large volume seawater samples were collected for the determination of 137Cs concentration along with depth in the deep basins of North and Central Aegean Sea. The vertical 137Cs distribution showed maximum concentration at the bottom of the basins, while the minimum values corresponded to the intermediate layer, where Levantine water exists. The surface 137Cs activity is found to lie between the two limits and is originated from the Black Sea waters. The typical oceanographic advection–diffusion balance model is modified to a diffusion-settling-decay balance model to better understand the vertical distribution and variation of the 137Cs concentration in the deep basins. In addition, the diffusivity of each basin, as well as the settling speed of particulate 137Cs is also estimated. The results are compared with theoretical approach as well as with previous data. - Highlights: • Three deep basins were studied using 137Cs as a tracer. • Deep waters constitute 137Cs repositories due to deep water formation followed Chernobyl accident. • Diffusivities, as well as particulate 137Cs settling speeds are estimated

  9. Climate change adaptation in a highly urbanized snowmelt dominated basin in Central Chile

    Science.gov (United States)

    Vicuna, S.; Bustos, E.; Merino, P.; Henriquez Dole, L. E.; Jansen, S.; Gil, M.; Ocampo, A.; Poblete, D.; Tosoni, D.; Meza, F. J.; Donoso, G.; Melo, O.

    2015-12-01

    The Maipo river basin holds 40% of Chile's total population and produces almost half of the country's Gross Domestic Product. The basin is located in the semiarid and snowmelt dominated central region of the country and, aside from the typical pressures of growth in developing country basins, the Maipo river basin faces climate change impacts associated with a reduction in total runoff and changes in its seasonality. Surface water is the main water source for human settlements, natural ecosystems, and economic activities including agriculture, mining and hydropower production. In 2012 a research project, called MAPA (Maipo Plan de Adaptacion), began with the objective of articulating a climate variability and climate change adaptation plan for the Maipo river basin. The project engaged at the beginning a group of relevant water and land use stakeholders which allowed for a good representation of critical aspects of an adaptation plan such as the definition of objectives and performance indicators, future land use scenarios, modeling of the different components of the system and design of adaptation strategies. The presentation will highlight the main results of the research project with a special focus on the upper catchments of the basin. These results include the assessment of impacts associated with future climate and land use scenarios on key components of the hydrologic cycle including snowmelt and glacier contribution to runoff and subsequent impacts on water availability for the operation of hydropower facilities, satisfaction of instream (recreation and aquatic ecosystem) uses and provision of water for the city of Santiago (7 million people) and to irrigate more than 100,000 hectares of high value crops. The integrative approach followed in this project including different perspectives on the use of water in the basin provides a good opportunity to test the varying degree of impacts that could be associated with a given future scenario and also understand

  10. Recovery of deep-sea meiofauna after artificial disturbance in the Central Indian Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Ingole, B.S.; Goltekar, N.R.; Gonsalves, S.; Ansari, Z.A.

    the Central Indian Ocean Basin. Deep-sea sediment sampling was conducted prior to benthic disturbance (i.e., in June 1997, termed as pre- disturbance sampling) and immediately after the disturbance in August 1997 (termed as post-disturbance). In order... to text figures Fig. 1: Position of the sampling stations in INDEX area (counters is depths in m.). Fig. 2: Meiobenthic abundance (no.10cm-2) in individual core during three INDEX phases. Fig. 3: Vertical distribution of meiofauna in test...

  11. Spatio-Temporal Variations and Source Apportionment of Water Pollution in Danjiangkou Reservoir Basin, Central China

    OpenAIRE

    Pan Chen; Lan Li; Hongbin Zhang

    2015-01-01

    Understanding the spatio-temporal variation and the potential source of water pollution could greatly improve our knowledge of human impacts on the environment. In this work, data of 11 water quality indices were collected during 2012–2014 at 10 monitoring sites in the mainstream and major tributaries of the Danjiangkou Reservoir Basin, Central China. The fuzzy comprehensive assessment (FCA), the cluster analysis (CA) and the discriminant analysis (DA) were used to assess the water pollutio...

  12. Inter-relationship between nuclei and gross characteristics of manganese nodules, Central Indian Ocean Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Sarkar, C.; Iyer, S.D.; Hazra, S.

    1 Author Version: Mar. Georesour. Geotechnol.: 26(4); 2008; 259-289 Inter-relationship between nuclei and gross characteristics of manganese nodules, Central Indian Ocean Basin Chiranjeeb Sarkar 1 , Sridhar D. Iyer 2 and Sugata Hazra 3 1... Department of Geological Sciences, Jadavpur University, Kolkata 700 032, India 2 National Institute of Oceanography, Dona Paula, Goa 403 004, India 3 School of Oceanographic Studies, Jadavpur University, Kolkata 700 032, India ABSTRACT More than 200...

  13. A tectonically controlled basin-fill within the Valle del Cauca, West-Central Colombia

    Energy Technology Data Exchange (ETDEWEB)

    Rine, J.M.; Keith, J.F. Jr.; Alfonso, C.A.; Ballesteros, I.; Laverde, F.; Sacks, P.E.; Secor, D.T. Jr. (Univ. of South Carolina, Columbia (United States)); Perez, V.E.; Bernal, I.; Cordoba, F.; Numpaque, L.E. (Ecopetrol, Bogota (Colombia))

    1993-02-01

    Tertiary strata of the Valle del Cauca reflect a forearc/foreland basin tectonic history spanning a period from pre-uplift of the Cordillera Central to initiation of uplift of the Cordillera Occidental. Stratigraphy of the Valle del Cauca begins with Jurassic-Cretaceous rocks of exotic and/or volcanic provenance and of oceanic origin. Unconformably overlying these are Eocene to Oligocene basal quartz-rich sandstones, shallow marine algal limestones, and fine-grained fluvial/deltaic mudstones and sandstones with coalbeds. These Eocene to Oligocene deposits represent a period of low tectonic activity. During late Oligocene to early Miocene, increased tectonic activity produced conglomeratic sediments which were transported from east to west, apparently derived from uplift of the Cordillera Central, and deposited within a fluvial to deltaic setting. East-west shortening of the Valle del Cauca basin folded the Eocene to early Miocene units, and additional uplift of the Cordillera Central during the later Miocene resulted in syn-tectonic deposition of alluvial fans. After additional fold and thrust deformation of the total Eocene-Miocene basin-fill, tectonic activity abated and Pliocene-Quaternary alluvial and lacustrine strata were deposited. Within the framework of this depositional and tectonic history of the Valle del Cauca, hydrocarbon exploration strategies can be formulated and evaluated.

  14. POSITIVE INVERSION STRUCTURE OF THE CENTRAL STRUCTURE BELT IN TURPAN-HAMI BASIN

    Institute of Scientific and Technical Information of China (English)

    ZHU Wenbin; MA Ruishi; GUO Lingzhi; SUN Yan; XU Mingjie; HU Dezhao

    2003-01-01

    The central structure belt in Turpan-Hami basin is composed of the Huoyanshan structure and Qiketai structure formed in late Triassic-early Jurassic, and is characterized by extensional tectonics. The thickness of strata in the hanging wall of the growth fault is obviously larger than that in the footwall,and a deposition center was evolved in the Taibei sag where the hanging wall of the fault is located. In late Jurassic the collision between Lhasa block and Eurasia continent resulted in the transformation of the Turpan-Hami basin from an extensional structure into a compressional structure, and consequently in the tectonic inversion of the central structure belt of the Turpan-Hami basin from the extensional normal fault in the earlier stage to the compressive thrust fault in the later stage. The Tertiary collision between the Indian plate and the Eurasian plate occurred around 55Ma, and this Himalayan orogenic event has played a profound role in shaping the Tianshan area, only the effect of the collision to this area was delayed since it culminated here approximately in late Oligocene-early Miocene. The central structure belt was strongly deformed and thrusted above the ground as a result of this tectonic event.

  15. CHARACTERIZATION AND FORMATION MECHANISM OF THE CENTRAL UPLIFT OF THE QIANGTANG BASIN

    Institute of Scientific and Technical Information of China (English)

    YIN Fuguang

    2004-01-01

    The Qiangtang basin is located between Kekexili-Jingshajiang suture belt and Bangong-Lujiang suture belt, and is divided into the north part and south part by the central uplift that has no crop out of Mesozoic strata. When the Jinshajiang Ocean was closed, the subducting plate was subducted southward. In the central part of the Qiangtang basin, the cushioning effect of the asthenosphere resulted in the thermal doming of the mantle and subsequent large-scale anatexis. Mantle source materials and antectic materials were upwelled and extruded into the middle crust, leading to the thickening of the middle crust and the heating and weakening of the middle to upper crust, and resulting in the rapid deformation (detachment) and tectonic erosion, and in the isostatic uplifting and the formation of metamorphic core complex. The upwelling of anatectic materials would further enhance the buoyant repercussion, which would combine with the side stress due from extrusion in resulting in the formation of an extensional stress field. The extensional structure and detachment fault are formed under the influence of the losing stabilized gravitation. In the deformation area in both the upper part and the lower part, an extensional deposition area would be formed, and this is the generation of a new basin.The metamorphic core complex of the central uplift is comprised of gneiss, which is itself overlain by non-metamorphic to weakly metamorphic covering strata intersected by faults.

  16. An unusual, dwarf new species of Neotropical freshwater stingray, Plesiotrygon nana sp. nov., from the upper and mid Amazon basin: the second species of Plesiotrygon (Chondrichthyes: Potamotrygonidae

    Directory of Open Access Journals (Sweden)

    Marcelo R. de Carvalho

    2011-01-01

    Full Text Available A new species of the relatively poorly known Neotropical freshwater stingray genus Plesiotrygon Rosa, Castello & Thorson, 1987 is described from the main channel and smaller tributaries (Ríos Itaya and Pachitea of the upper Amazon basin in Peru. The first specimen to be collected, however, was from much farther east in Rio Solimões in 1996, just down-river from Rio Purus (specimen unavailable for this study. Plesiotrygon nana sp. nov., is a very distinctive and unusually small species of freshwater stingray (Potamotrygonidae, described here mostly from three specimens representing different size classes and stages of sexual maturity. Plesiotrygon nana sp. nov., is distinguished from its only congener, P. iwamae Rosa, Castello & Thorson, 1987, by numerous unique features, including: dorsal coloration composed of very fine rosettes or a combination of spots and irregular ocelli; very circular disc and snout; very small and less rhomboidal spiracles; short snout and anterior disc region; narrow mouth and nostrils; denticles on dorsal tail small, scattered, not forming row of enlarged spines; adult and preadult specimens with significantly fewer tooth rows; fewer caudal vertebrae; higher total pectoral radials; very small size, probably not surpassing 250 mm disc length or width, males maturing sexually at around 180 mm disc length and 175 mm disc width; distal coloration of tail posterior to caudal stings usually dark purplish-brown; and features of the ventral lateral-line canals (hyomandibular canal very narrow, infraorbital and supraorbital canals not undulated, supraorbital and infraorbital loops small and narrow, supraorbital loop very short, not extending posteriorly to level of mouth, jugular and posterior infraorbital canals short, not extending caudally to first gill slits, subpleural loop very narrow posteriorly; absence of anterior and posterior subpleural tubules. To provide a foundation for the description of P. nana sp. nov

  17. Manganese and Mercury Levels in Water, Sediments, and Children Living Near Gold-Mining Areas of the Nangaritza River Basin, Ecuadorian Amazon.

    Science.gov (United States)

    González-Merizalde, Max V; Menezes-Filho, José A; Cruz-Erazo, Claudia Teresa; Bermeo-Flores, Santos Amable; Sánchez-Castillo, María Obdulia; Hernández-Bonilla, David; Mora, Abrahan

    2016-08-01

    Artisanal and small-scale gold-mining activities performed in mountain areas of the Southern Ecuadorian Amazon have incorporated several heavy metals into the aquatic systems, thus increasing the risk of exposure in populations living in adjacent zones. Therefore, the objective of this study was to evaluate the contamination levels of mercury (Hg) and manganese (Mn) in several rivers of the Nangaritza River basin and assess the exposure in school-aged children residing near the gold-mining zones. River water and sediment samples were collected from a highly contaminated (HEx) and a moderately contaminated (MEx) zones. Hair Mn (MnH) and urinary Hg (HgU) levels were determined in school-aged children living in both zones. High concentrations of dissolved Mn were found in river waters of the HEx zone (between 2660 and 3990 µg l(-1)); however, Hg levels, in general, were lower than the detection limit (DL; <1.0 µg l(-1)). Similarly, Mn levels in sediments were also increased (3090 to 4086 µg g(-1)). Median values of MnH in children of the HEx and MEx zones were 5.5 and 3.4 µg g(-1), respectively, whereas the median values of HgU concentrations in children living in the HEx and MEx zones were 4.4 and 0.62 µg g-creat(-1), respectively. Statistically significant differences were observed between both biomarkers in children from the HEx and MEx zones. In addition, boys presented significantly greater MnH levels in both zones. The greater MnH values were found in children living in alluvial areas, whereas children living in the high mountain areas, where some ore-processing plants are located close to or inside houses and schools, had the greater HgU concentrations. In summary, the data reported in this paper highlights that artisanal and small-scale gold-mining activities can not only produce mercurial contamination, that can also release other heavy metals (such as Mn) that may pose a risk to human health.

  18. Real-time measurements of ammonia, acidic trace gases and water-soluble inorganic aerosol species at a rural site in the Amazon Basin

    Directory of Open Access Journals (Sweden)

    I. Trebs

    2004-01-01

    Full Text Available We measured the mixing ratios of ammonia (NH3, nitric acid (HNO3, nitrous acid (HONO, hydrochloric acid (HCl, sulfur dioxide (SO2 and the corresponding water-soluble inorganic aerosol species, ammonium (NH4+, nitrate (NO3-, nitrite (NO2-, chloride (Cl- and sulfate (SO42-, and their diel and seasonal variations at a pasture site in the Amazon Basin (Rondônia, Brazil. This study was conducted within the framework of LBA-SMOCC (Large Scale Biosphere Atmosphere Experiment in Amazonia - Smoke Aerosols, Clouds, Rainfall and Climate: Aerosols from Biomass Burning Perturb Global and Regional Climate. Sampling was performed from 12 September to 14 November 2002, extending from the dry season (extensive biomass burning activity, through the transition period to the wet season (background conditions. Measurements were made continuously using a wet-annular denuder (WAD in combination with a Steam-Jet Aerosol Collector (SJAC followed by suitable on-line analysis. A detailed description and verification of the inlet system for simultaneous sampling of soluble gases and aerosol compounds is presented. Overall measurement uncertainties of the ambient mixing ratios usually remained below 15%. The limit of detection (LOD was determined for each single data point measured during the field experiment. Median LOD values (3σ-definition were ≤0.015ppb for acidic trace gases and aerosol anions and ≤0.118ppb for NH3 and aerosol NH4+. Mixing ratios of acidic trace gases remained below 1ppb throughout the measurement period, while NH3 levels were an order of magnitude higher. Accordingly, mixing ratios of NH4+ exceeded those of other inorganic aerosol contributors by a factor of 4 to 10. During the wet season, mixing ratios decreased by nearly a factor of 3 for all compounds compared to those observed when intensive biomass burning took place. Additionally, N-containing gas and aerosol species featured pronounced diel variations. This is attributed to strong

  19. Real-time measurements of ammonia, acidic trace gases and water-soluble inorganic aerosol species at a rural site in the Amazon Basin

    Directory of Open Access Journals (Sweden)

    I. Trebs

    2004-02-01

    Full Text Available We measured the mixing ratios of ammonia (NH3, nitric acid (HNO3, nitrous acid (HONO, hydrochloric acid (HCl, sulfur dioxide (SO2 and the corresponding water-soluble inorganic aerosol species, ammonium (NH4+, nitrate (NO3, nitrite (NO2, chloride (Cl and sulfate (SO42−, and their diel and seasonal variations at a pasture site in the Amazon Basin (Rondônia, Brazil. This study was conducted within the framework of LBA-SMOCC (Large Scale Biosphere Atmosphere Experiment in Amazonia Smoke Aerosols, Clouds, Rainfall and Climate. Sampling was performed from 12 September to 14 November 2002, extending from the dry season (extensive biomass burning activity, through the transition period to the wet season (background conditions. Measurements were made continuously using a wet-annular denuder in combination with a Steam-Jet Aerosol Collector (SJAC followed by suitable on-line analysis. A detailed description and verification of the inlet system for simultaneous sampling of soluble gases and aerosol compounds is presented. Overall measurement uncertainties of the ambient mixing ratios usually remained below 15%. The limit of detection (LOD was determined for each single data point measured during the field experiment. Median LOD values (3σ-definition were ≤0.015 ppb for acidic trace gases and aerosol anions and ≤0.118 ppb for NH3 and aerosol NH4+. Mixing ratios of acidic trace gases remained below 1ppb throughout the measurement period, while NH3 levels were an order of magnitude higher. Accordingly, mixing ratios of NH4+ exceeded those of other inorganic aerosol contributors by a factor of 4 to 10. During the wet season, mixing ratios decreased by nearly a factor of 3 for all compounds compared to those observed when intensive biomass burning

  20. Seasonal variations in the stable oxygen isotope ratio of wood cellulose reveal annual rings of trees in a Central Amazon terra firme forest.

    Science.gov (United States)

    Ohashi, Shinta; Durgante, Flávia M; Kagawa, Akira; Kajimoto, Takuya; Trumbore, Susan E; Xu, Xiaomei; Ishizuka, Moriyoshi; Higuchi, Niro

    2016-03-01

    In Amazonian non-flooded forests with a moderate dry season, many trees do not form anatomically definite annual rings. Alternative indicators of annual rings, such as the oxygen (δ(18)Owc) and carbon stable isotope ratios of wood cellulose (δ(13)Cwc), have been proposed; however, their applicability in Amazonian forests remains unclear. We examined seasonal variations in the δ(18)Owc and δ(13)Cwc of three common species (Eschweilera coriacea, Iryanthera coriacea, and Protium hebetatum) in Manaus, Brazil (Central Amazon). E. coriacea was also sampled in two other regions to determine the synchronicity of the isotopic signals among different regions. The annual cyclicity of δ(18)Owc variation was cross-checked by (14)C dating. The δ(18)Owc showed distinct seasonal variations that matched the amplitude observed in the δ(18)O of precipitation, whereas seasonal δ(13)Cwc variations were less distinct in most cases. The δ(18)Owc variation patterns were similar within and between some individual trees in Manaus. However, the δ(18)Owc patterns of E. coriacea differed by region. The ages of some samples estimated from the δ(18)Owc cycles were offset from the ages estimated by (14)C dating. In the case of E. coriacea, this phenomenon suggested that missing or wedging rings may occur frequently even in well-grown individuals. Successful cross-dating may be facilitated by establishing δ(18)Owc master chronologies at both seasonal and inter-annual scales for tree species with distinct annual rings in each region.

  1. Petrographic characterization and preliminary geochronologic data from volcanic rocks of the Iriri formation, southern-central portion of the Amazon Craton, Aripuana - Mato Grosso

    International Nuclear Information System (INIS)

    The Moriru area is located in the south-central portion of the Amazon Craton, near the border of Mato Grosso and Amazonas states. The research was carried out using eight drill cores, 200 meters deep in average. The description of these drill cores allowed the identification of felsic lavas and pyroclastics inter layered with mafic flows volcanoclastic and sedimentary rocks. Granitic intrusions are completely altered by hydrothermal metamorphism. Later stage dikes were identified. The pyroclastic successions is characterized by ignimbritic rocks generated by pumice flows. The ignimbrites are enriched in pumice and phenocrysts and are classified as crystal enriched ignimbrite. The content of fine particles is low and the welding grade ranges from good to medium. The composition of ignimbrites is rhyodacite to dacite. U-Pb zircon ages are 1801+- 11 Ma for ignimbrites and 1848+-9 Ma for mafic volcanics. However, for the mafic rocks age may represent some inherited zircon. More data from these rocks are necessary before we can make a definitive conclusion. The air fall deposits are represented by ash tuff enriched in vitroclasts. The volcanogenic sedimentary deposits occur inter layered with pyroclastic deposits and are represented by volcanoclastic conglomerates and immature tuffaceous sandstones. The volcanic particles in this sequence, partially maintain igneous characteristics, which suggests small amount of reworking and a possible proximity to the source. Sulfides occur disseminated in sub-volcanic and in late-stage quartz-carbonate-chlorite veins. (author)

  2. Aerosols Optical Depth spatial variation over the Amazon basin during winter. Comparison with AOD summer behavior over the Caribbean islands

    Science.gov (United States)

    Molinie, J.; Gobinddass, M.; Henry, J.

    2012-12-01

    Natural Atmospheric particles have important effects on climate and human health. Desert dust particles, a major part of them present the ability to be transported over long distances and impact large regions of the earth. The development of space-borne passive remote sensing of dust and their ground validations allow us to approach the dust physical characteristics on a large scale. Here we were interested to the Saharan dust transport and characteristics over French Guiana. First, we have tried to found relationships between the mass concentration repartition of different sites (closer to land interior/closer to the coast). We chose two sites separated by near 100 km on the coast, Cayenne and Sinnamary, and a site in the land interior, Rochambeau. We used a set PM10 measured mass concentration to calculate the ground spatial variability. For the same time and over the same geographical points we studied the spatial variability of the data MODIS pictures of the Aerosols Optical Depth. We compared the ground based results and the satellite one to obtain the correlation existing between low atmospheric PM10 measures and upper level AOD. We used the same approach over central Atlantic during summer dust period. A discussion about the behavior of the AOD spatial variability of the summer dust transport over the Caribbean islands and the winter transport over South America is finally led.

  3. The U.S. Geological Survey`s National Coal Resource Assessment: The Northern and Central Appalachian Basin

    Energy Technology Data Exchange (ETDEWEB)

    Ruppert, L.; Bragg, L.; Tewalt, S. [Geological Survey, Reston, VA (United States)

    1996-09-01

    The US Geological Survey (USGS) Energy Resource Surveys Program is currently conducting a five-year National Coal Resource Assessment project. Primary focus is on the quality and quantity of top-producing coal beds and coal zones in five of the nine major coal producing regions in the US. These regions include the (1) Northern and Central Appalachian Basin, (2) Gulf Coastal Plain, (3) Illinois Basin, (4) Colorado Plateau, and (5) Powder River Basin and Northern Great Plains.

  4. Salar de Atacama basin: A record of compressional tectonics in the central Andes since the mid-Cretaceous

    OpenAIRE

    ARRIAGADA, César; Cobbold, Peter,; Roperch, Pierrick

    2006-01-01

    19 p.; International audience; The Salar de Atacama basin lies in the inner fore arc of northern Chile. Topographically and structurally, it is a first-order feature of the central Andes. The sedimentary fill of the basin constrains the timing and extent of crustal deformation since the mid-Cretaceous. We have studied good exposures along the western edge of the basin and have correlated them with seismic reflection sections and data from an exploration well. Throughout most of its history, t...

  5. A study on the evolution of Indian Ocean triple junction and the process of deformation in the Central Indian Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Murthy, K.S.R.; Rao, T.C.S.

    It is generally presumed that the intraplate deformation in the Central Indian Basin (CIB) is a direct consequence of spreading across the South East Indian Ridge and the resistance to shortening at the continental collision between India...

  6. Hydrocarbons in the Bay of Bengal and Central Indian Basin bottom sediments: Indicators of geochemical processes in the lithosphere

    Digital Repository Service at National Institute of Oceanography (India)

    Chernova, T.G.; Paropkari, A.L.; Pikovskii, Yu.I.; Alekseeva, T.A.

    that the hydrocarbons are mostly derived from marine sources. Sharp increases fo hydrocarbons are found in the vicinity of the tectonically active region of the Central Indian Basin, particularly in the sediments collected from the fracture zone. The total concentration...

  7. Effect of benthic disturbance on geotechnical characteristics of sediments from nodule mining area in the Central Indian Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Khadge, N.H.

    Benthic disturbance is carried out in the Central Indian Basin for environmental impact assessment studies. Geotechnical measurements were made on sediments collected before and after disturbing the top 10-15 cm of the seafloor. Results indicate...

  8. Nature and distribution of manganese nodules from three sediment domains of the Central Indian Basin, Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Banerjee, R.; Mukhopadhyay, R.

    Manganese nodules from the Central Indian Basin (5 degrees-10 degrees S) vary in abundance, morphology, mineralogy, and chemistry with water depth and sediment type. Nodules from the southern region, dominatEd. by siliceous sediment, differ markedly...

  9. Climate Change Impacts on Runoff Regimes at a River Basin Scale in Central Vietnam

    Directory of Open Access Journals (Sweden)

    Do Hoai Nam

    2012-01-01

    Full Text Available Global warming has resulted in significant variability of global climate especially with regard to variation in temperature and precipitation. As a result, it is expected that river flow regimes will be accordingly varied. This study presents a preliminary projection of medium-term and long-term runoff variation caused by climate change at a river basin scale. The large scale precipitation projection at the middle and the end of the 21st century under the A1B scenario simulated by the CGCM model (MRI & JMA, 300 km resolution is statistically downscaled to a basin scale and then used as input for the super-tank model for runoff analysis at the upper Thu Bon River basin in Central Vietnam. Results show that by the middle and the end of this century annual rainfall will increase slightly; together with a rising temperature, potential evapotranspiration is also projected to increase as well. The total annual runoff, as a result, is found to be not distinctly varied relative to the baseline period 1981 - 2000; however, the runoff will decrease in the dry season and increase in the rainy season. The results also indicate the delay tendency of the high river flow period, shifting from Sep-Dec at present to Oct-Jan in the future. The present study demonstrates potential impacts of climate change on streamflow regimes in attempts to propose appropriate adaptation measures and responses at the river basin scales.

  10. Determination of hydrocarbon prospective areas in the Tuzgolu (Saltlake) Basin, central Anatolia, by using geophysical data

    Energy Technology Data Exchange (ETDEWEB)

    Aydemir, Attila [Turkiye Petrolleri A.O. Mustafa Kemal Mah. 2.Cad. No: 86, 06100 Sogutozu, Ankara (Turkey); Ates, Abdullah [Ankara University, Faculty of Engineering, Department of Geophysical Engineering, 06100, Besevler, Ankara (Turkey)

    2008-09-15

    Tuzgolu Basin is the largest interior basin in Central Anatolia, Turkey, with significant hydrocarbon indications in outcrops and exploration wells. However, there is no commercial discovery since 1959 which is the beginning year of exploration activities. Because of the poor seismic quality, all available geological-geophysical data and methods should be used in integration with each other to carry out exploration activities. In previous studies, the basin was modeled three dimensionally (3D) using gravity data by the authors of this paper and results of the modeling study were published recently. The model results can be evaluated to determine probable hydrocarbon generation zones. Gravity anomalies in this region exhibit many inflections that could be prospective locations for hydrocarbons. In this study, the gravity data were subjected to the vertical derivative in order to isolate inflections and to determine concealed structurally high areas in the subsurface that could have hydrocarbon potential. These potential subsurface structures were also compared with the Analytical Signal map produced from the aeromagnetic anomalies to reveal if they are originated from a magmatic intrusion. Finally, it was determined that all exploration wells were drilled off-structure and none of these potential subsurface structures was tested. According to correlation of the previous well locations and determined subsurface structures in or around the hydrocarbon generation zones, it is possible to claim that the Tuzgolu Basin with no previous discovery remains prospective for hydrocarbon exploration activities in the future. (author)

  11. Holocene mammalian change in the central Columbia Basin of eastern Washington state, USA

    Science.gov (United States)

    Lyman, R. Lee

    2016-08-01

    Predictions of changes in the Holocene mammalian fauna of the central Columbia Basin in eastern Washington (USA) based on environmental changes are largely met. Taxonomic richness is greatest during periods of cool-moist climate. Rates of input of faunal remains to the paleozoological record may suggest greater mammalian biomass during periods of greater moisture but are difficult to interpret without data on sampling intensity in the form of volume of sediment excavated. Abundances of leporids and grazing ungulates fluctuate in concert with abundance of grass. Several biogeographic records are tantalizing but require additional study and data before being accepted as valid. Records of red fox (Vulpes vulpes) indicate this species was present in the central basin during the Holocene contrary to historic records and recent suggestions modern foxes there are escapees from fur farms. Bison (Bison bison) and bighorn sheep (Ovis canadensis) underwent diminution of body size during the Holocene. Modern efforts to conserve the Columbia Basin ecosystem are advised to consider the Holocene record as indicative of what may happen to that ecosystem in the future.

  12. Conventional tree height-diameter relationships significantly overestimate aboveground carbon stocks in the Central Congo Basin

    Science.gov (United States)

    Kearsley, Elizabeth; Hufkens, Koen; Steppe, Kathy; Beeckman, Hans; Boeckx, Pascal; Verbeeck, Hans

    2014-05-01

    Accurate estimates of the amount of carbon stored in tropical forests represent crucial baseline data for recent climate change mitigation policies. Such data are needed to quantify possible emissions due to deforestation and forest degradation, and to evaluate the potential of these forests to act as carbon sinks. Currently, only rough estimates of the carbon stocks for Central African tropical forests are available due to a lack of field data, and little is known about the response of these stocks to climate change. We present the first field-based carbon stock data for the Central Congo Basin in Yangambi, Democratic Republic of Congo. We found an average aboveground carbon stock of 162 ± 20 Mg C ha-1 for intact old-growth forest, which is significantly lower than stocks recorded in the outer regions of the Congo Basin. The best available tree height-diameter relationships derived for Central Africa do not render accurate canopy height estimates for our study area. Aboveground carbon stocks would be overestimated by 24% if these inaccurate relationships were used. The studied forests have a lower stature compared with forests in the outer regions of the basin, which confirms remotely sensed patterns. We identified a significant difference in height-diameter relations across the Congo Basin as a driver for spatial differences in carbon stocks. The study of a more detailed interaction of the environment and the available tree species pool as drivers for differences in carbon storage could have large implications. The effect of the species pool on carbon storage can be large since species differ in their ability to sequester carbon, and the collective functional characteristics of plant communities could be a major driver of carbon accumulation. Numerous species-specific tree height-diameter relations are established for two sites around Kisangani, central Congo Basin, with differing stand height-diameter relationships. The species-specific relations for the two

  13. Federally owned coal and Federal lands in the northern and central Appalachian Basin coal regions

    Energy Technology Data Exchange (ETDEWEB)

    Susan J. Tewalt

    2002-02-01

    The US Geological Survey (USGS) assessed five coals beds or coal zones in the northern and central Appalachian Basin coal regions for the National Coal Resource Assessment: the Pittsburgh coal bed, the Upper Freeport coal bed, the Fire Clay coal zone, the Pond Creek coal zone, and the Pocahontas No. 3 coal bed. The assessment produced stratigraphic and geochemical databases and digital coal maps, or models, which characterized the coal beds and coal zones. Using the assessment models, the USGS estimated original and remaining (unmined) resources for these coal beds or zones. The Appalachian Basin assessment was conducted in collaboration with the State geological surveys of West Virginia, Pennsylvania, Ohio, Maryland, Kentucky, and Virginia. 3 refs., 7 figs.

  14. Coal resources of selected coal beds and zones in the northern and central Appalachian Basin

    Energy Technology Data Exchange (ETDEWEB)

    Leslie Ruppert; Susan Tewalt; Linda Bragg

    2002-02-01

    The U.S. Geological Survey (USGS) is completing a National Coal Resource Assessment of five coal-producing regions of the United States, including the Appalachian Basin. The USGS, in cooperation with the State geological surveys of Kentucky, Maryland, Ohio, Pennsylvania, Virginia, and West Virginia, has completed a digital coal resource assessment of five of the top-producing coal beds and coal zones in the northern and central Appalachian Basin coal regions -- the Pittsburgh coal bed, the Upper Freeport coal bed, the Fire Clay and Pond Creek coal zones, and the Pocahontas No. 3 coal bed. Of the 93 billion short tons of original coal in these units, about 66 billion short tons remain. 2 refs., 5 figs., 2 tabs.

  15. Preliminary description of hydrologic characteristics and contaminant transport potential of rocks in the Pasco Basin, south-central Washington

    International Nuclear Information System (INIS)

    This report aims at consolidating existing data useful in defining the hydrologic characteristics of the Pasco Basin within south-central Washington. It also aims at compiling the properties required to evaluate contaminant transport potential within individual subsurface strata in this basin. The Pasco Basin itself is a tract of semi-arid land covering about 2,000 square miles in south-central Washington. The regional geology of this basin is dominated by tholeiitic flood basalts of the Columbia Plateau. The surface hydrology of the basin is dominated by the Yakima, Snake, and Columbia rivers. Short-lived ephemeral streams may flow for a short period of time after a heavy rainfall or snowmelt. The subsurface hydrology of the Pasco Basin is characterized by an unconfined aquifer carrying the bulk of the water discharged within the basin. This aquifer overlies a series of confined aquifers carrying progressively smaller amounts of groundwater as a function of depth. The hydraulic properties of the various aquifers and non-water-bearing strata are characterized and reported. A summary of the basic properties is tabulated. The hydrochemical data obtained are summarized. The contaminant transport properties of the rocks in the Pasco Basin are analyzed with emphasis on the dispersion and sorption coefficients and the characteristics of the potential reactions between emplaced waste and the surrounding medium. Some basic modeling considerations of the hydrogeologic systems in the basin with a brief discussion of model input requirements and their relationship to available data are presented

  16. Four new combinations in Chomelia and Stenostomum (Rubiaceae, Guettardeae) from Central America, the Guianas and the Amazon Basin

    NARCIS (Netherlands)

    Delprete, P.G.; Achille, F.; Mouly, A.

    2010-01-01

    According to current generic delimitations, supported by wood anatomy, palynology, and recent molecular phylogenies, Antirhea, traditionally treated as a Pantropical genus, is instead restricted to the Paleotropics. At the same time, the Neotropical species traditionally positioned in Antirhea shoul

  17. Paleoseismological investigations and Geomorphology on the Gaenserndorf Terrace in the central Vienna Basin (Austria)

    Science.gov (United States)

    Weissl, Michael; Hintersberger, Esther; Lomax, Johanna; Decker, Kurt

    2016-04-01

    In the central Vienna Basin normal faults define the eastern and western margins of Pleistocene Danube terraces north of Vienna. The terrace body is built up of coarse sandy gravel and sand. Locally the terrace surface is covered with eolian and alluvial sediments of the last glacial revealing OSL/IRSL ages of about 15-16 ka. High resolution digital terrain models (LIDAR) show relicts of a periglacial landscape in the northern part of the Middle Pleistocene (MIS 8) terrace. Large elongated depressions in the northern parts of the terrace are interpreted as the basins of former thermokarst lakes due to analogies in recent periglacial zones. Draining valleys corrugate the fault scarps indicating advanced subsidence of the Aderklaa and Obersiebenbrunn Quaternary basins before the last Glacial. Obviously the periglacial morphology is only preserved in the elevated parts of the terrace which is located in the footwall of the bounding normal faults. In the hanging wall Quaternary basins are filled with up to 40 m thick Pleistocene and Holocene growth strata. During the last decade three faults were investigated by trenching. In contrast to the earlier trench sites on the Markgrafneusiedl Fault and the Vienna Basin Transform Fault it was not possible to provide clear evidence for offset on the Aderklaa-Bockfliess fault because cryoturbation deformed the covering fluvial sediments together with the underlying Gaenserndorf terrace gravels. However it was possible to localize this fault precisely applying an electrical resistivity tomography. The resulting ERT-section shows an offset of the 200-300 ky old terrace and the underlying Miocene sediments of about 9-10 meters suggesting a vertical slip rate of 0.03 - 0.05 mm/a.

  18. Long term spatial and temporal rainfall trends and homogeneity analysis in Wainganga basin, Central India

    Directory of Open Access Journals (Sweden)

    Arun Kumar Taxak

    2014-08-01

    Full Text Available Gridded rainfall data of 0.5×0.5° resolution (CRU TS 3.21 was analysed to study long term spatial and temporal trends on annual and seasonal scales in Wainganga river basin located in Central India during 1901–2012. After testing the presence of autocorrelation, Mann–Kendall (Modified Mann–Kendall test was applied to non-auto correlated (auto correlated series to detect the trends in rainfall data. Theil and Sen׳s slope estimator test was used for finding the magnitude of change over a time period. For detecting the most probable change year, Pettitt–Mann–Whitney test was applied. The Rainfall series was then divided into two partial duration series for finding changes in trends before and after the change year. Arc GIS was used to explore spatial patterns of the trends over the entire basin. Though most of the grid points shows a decreasing trend in annual rainfall, only seven grids has a significant decreasing trend during 1901–2012. On the basis of seasonal trend analysis, non-significant increasing trend is observed only in post monsoon season while seven grid points show significant decreasing trend in monsoon rainfall and non-significant in pre-monsoon and winter rainfall over the last 112 years. During the study period, overall a 8.45% decrease in annual rainfall is estimated. The most probable year of change was found to be 1948 in annual and monsoonal rainfall. There is an increasing rainfall trend in the basin during the period 1901–1948, which is reversed during the period 1949–2012 resulting in decreasing rainfall trend in the basin. Homogeneous trends in annual and seasonal rainfall over a grid points is exhibited in the basin by van Belle and Hughes׳ homogeneity trend test.

  19. A review of green- and blue-water resources and their trade-offs for future agricultural production in the Amazon Basin: what could irrigated agriculture mean for Amazonia?

    Science.gov (United States)

    Lathuillière, Michael J.; Coe, Michael T.; Johnson, Mark S.

    2016-06-01

    The Amazon Basin is a region of global importance for the carbon and hydrological cycles, a biodiversity hotspot, and a potential centre for future economic development. The region is also a major source of water vapour recycled into continental precipitation through evapotranspiration processes. This review applies an ecohydrological approach to Amazonia's water cycle by looking at contributions of water resources in the context of future agricultural production. At present, agriculture in the region is primarily rain-fed and relies almost exclusively on green-water resources (soil moisture regenerated by precipitation). Future agricultural development, however, will likely follow pathways that include irrigation from blue-water sources (surface water and groundwater) as insurance from variability in precipitation. In this review, we first provide an updated summary of the green-blue ecohydrological framework before describing past trends in Amazonia's water resources within the context of land use and land cover change. We then describe green- and blue-water trade-offs in light of future agricultural production and potential irrigation to assess costs and benefits to terrestrial ecosystems, particularly land and biodiversity protection, and regional precipitation recycling. Management of green water is needed, particularly at the agricultural frontier located in the headwaters of major tributaries to the Amazon River, and home to key downstream blue-water users and ecosystem services, including domestic and industrial users, as well as aquatic ecosystems.

  20. New species of Moenkhausia Eigenmann (Ostariophysi: Characidae) from the upper rio Tocantins basin in Central Brazil

    OpenAIRE

    Vinicius A. Bertaco; Fernando C Jerep; Fernando R Carvalho

    2011-01-01

    Moenkhausia dasalmas is described from the upper rio Tocantins basin, in the Chapada dos Veadeiros region, Goiás State, Central Brazil. The new species differs from all congeners by the presence of iii,9 rays in the dorsal fin. It can also be distinguished from its congeners by the presence of two humeral spots (first one vertically elongate and second one faint), by the number of branched anal-fin rays (17-19), lateral line scales (36-37), maxillary teeth (4-5), and a vertical dark spot in t...

  1. Response of meiofauna to immediate benthic disturbance in the Central Indian Ocean Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Ingole, B.S.; Ansari, Z.A.; Rathod, V.; Rodrigues, N.

    Marine Georesources and Geotechnology,18:263–272,2000Copyright ©2000 Taylor & Francis1064-119X / 00 $12.00 1 .00 Response of Meiofauna to Immediate Benthic Disturbance in the Central Indian Ocean Basin B. S. INGOLEZ. A. ANSARIV. RATHODN. RODRIGUES... will potentially produce some undesirable environmentalefects,both in the water column and on the seabed (Berge et al.,1991; Thiel et al.,1992).Possible effects are expected to involve habitat changes,resulting in biotic responses to changes as well as direct...

  2. INTEGRATING GEOPHYSICS, GEOLOGY, AND HYDROLOGY TO DETERMINE BEDROCK GEOMETRY CONTROLS ON THE ORIGIN OF ISOLATED MEADOW COMPLEXES WITHIN THE CENTRAL GREAT BASIN, NEVADA

    Science.gov (United States)

    Riparian meadow complexes found in mountain ranges of the Central Great Basin physiographic region (western United States) are of interest to researchers as they contain significant biodiversity relative to the surrounding basin areas. These meadow complexes are currently degradi...

  3. Seven new species of Lachesilla (Psocodea: 'Psocoptera': Lachesillidae, in the group forcepeta from the Amazon Basin Sete espécies novas de Lachesilla Westwood (Psocodea:'Psocoptera': Lachesillidae do grupo forcepeta da Bacia Amazônica

    Directory of Open Access Journals (Sweden)

    Alfonso N. García Aldrete

    2010-12-01

    Full Text Available Seven new species of Lachesilla in the group forcepeta, from the Amazon Basin in Brazil, Colombia and Peru, are here described and illustrated: L. amacayacuensis sp. n. (type locality: Colombia, Amazonas, Leticia, Amacayacú; L.bulbosiforceps sp. n. (type locality: Peru, Cuzco; L. cuzcoensis sp. n. (type locality: Peru, Cuzco; L. marabaensis sp. n. (type locality: Brasil, Pará, Marabá, Serra Norte; L. pilosiforceps sp. n. (type locality: Brasil, Pará, Oriximiná, Rio Trombetas; L. pilosipenna sp. n. (type locality: Peru, Cuzco; L. squamiforceps sp. n. (type locality: Colombia, Amazonas, Leticia. The Amazon Basin is the second most rich world area for species of Lachesilla.São descritas e ilustradas sete espécies de Lachesilla do grupo forcepeta, provenientes da bacia amazônica do Brasil, Colômbia e Peru: L. amacayacuensis sp. n. (localidade-tipo: Colômbia, Amazonas, Leticia, Amacayacú; L. bulbosiforceps sp. n. (localidade-tipo: Peru, Cuzco; L. cuzcoensis sp. n. (localidade-tipo: Peru, Cuzco; L. marabaensis sp. n. (localidade-tipo: Brasil, Pará, Marabá, Serra Norte; L. pilosiforceps sp. n. (localidade-tipo: Brasil, Pará, Oriximiná, Rio Trombetas; L. pilosipenna sp. n. (localidade-tipo: Peru, Cuzco; L. squamiforceps sp. n. (localidade-tipo: Colômbia, Amazonas, Letícia. A região amazônica é a segunda mais rica em número de espécies de Lachesilla.

  4. GoAmazon – Scaling Amazon Carbon Water Couplings

    Energy Technology Data Exchange (ETDEWEB)

    Dubey, Manvendra Krishna [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-09-06

    Forests soak up 25% of the carbon dioxide (CO2) emitted by anthropogenic fossil energy use (10 Gt C y-1) moderating its atmospheric accumulation. How this terrestrial CO2 uptake will evolve with climate change in the 21st century is largely unknown. Rainforests are the most active ecosystems with the Amazon basin storing 120 Gt C as biomass and exchanging 18 Gt C y-1 of CO2 via photosynthesis and respiration and fixing carbon at 2-3 kg C m-2 y-1. Furthermore, the intense hydrologic and carbon cycles are tightly coupled in the Amazon where about half of the water is recycled by evapotranspiration and the other half imported from the ocean by Northeasterly trade winds. Climate models predict a drying in the Amazon with reduced carbon uptake while observationally guided assessments indicate sustained uptake. We will resolve this huge discrepancy in the size and sign of the future Amazon carbon cycle by performing the first simultaneous regional scale high frequency measurements of atmospheric CO2, H2O, HOD, CH4, N2O and CO at the T3 site in Manacupuru, Brazil as part of DOE's GoAmazon project. Our data will be used to inform and develop DOE's CLM on the tropical carbon-water couplings at the appropriate grid scale (10-50km). Our measurements will also validate the CO2 data from Japan's GOSAT and NASA's imminent OCO-2 satellite (launch date July 2014).

  5. Evidences for Incipient Hydrothermal Event(s) in the Central Indian Basin:A Review

    Institute of Scientific and Technical Information of China (English)

    Sridhar D. IYER

    2005-01-01

    The Central Indian Basin (CIB, 10°-19°S) encompasses morphotectonic features such as seamounts, abyssal hills, faults, fracture zones and lineations and basic to silicic volcanics that were derived from different sources. Instances of incipient hydrothermal event (s) occurred as evident from: (1) spilites that probably formed due to low-temperature hydrothermal action on the precursory basalts, (2) slabs and fragments of zeolitites which are the consequent products of palagonitization of the basaltic glasses, (3) chemical variations in the ferromanganese crusts, and (4) abundance of volcanogenic-hydrothermal material (vhm) that includes ochrous sediments and magnetite spherules. The vhm suggests its origin by interaction of Fe-rich hydrothermal solutions with surrounding sediments. The CIB spherules occur in sediments of ~10 ka and ~425 to 650 ka age and are orders of magnitude younger than the 50 to 60 Ma age of the basin. Incidentally,to the north of the basin at ODP Site 717-719 (1 °S/81 °E) hydrothermal precipitates of inorganic calcite and deposition of sulphide minerals (~7.5 to 9 Ma and 0.5 Ma) occur as a result of the on-going intraplate deformation. This paper reviews the above evidences that possibly indicate episodes of localized hydrothermal events in the CIB.

  6. Ethiopian Central Rift Valley basin hydrologic modelling using HEC-HMS and ArcSWAT

    Science.gov (United States)

    Pascual-Ferrer, Jordi; Candela, Lucila; Pérez-Foguet, Agustí

    2013-04-01

    An Integrated Water Resources Management (IWRM) shall be applied to achieve a sustainable development, to increase population incomes without affecting lives of those who are highly dependent on the environment. First step should be to understand water dynamics at basin level, starting by modeling the basin water resources. For model implementation, a large number of data and parameters are required, but those are not always available, especially in some developing countries where different sources may have different data, there is lack of information on data collection, etc. The Ethiopian Central Rift Valley (CRV) is an endorheic basin covering an area of approximately 10,000 km2. For the period 1996-2005, the average annual volume of rainfall accounted for 9.1 Mm3, and evapotranspiration for 8 Mm3 (Jansen et al., 2007). From the environmental point of view, basin ecosystems are endangered due to human activities. Also, poverty is widespread all over the basin, with population mainly living from agriculture on a subsistence economy. Hence, there is an urgent need to set an IWRM, but datasets required for water dynamics simulation are not too reliable. In order to reduce uncertainty of numerical simulation, two semi-distributed open software hydrologic models were implemented: HEC-HMS and ArcSWAT. HEC-HMS was developed by the United States Army Corps of Engineers (USACoE) Hydrologic Engineering Center (HEC) to run precipitation-runoff simulations for a variety of applications in dendritic watershed systems. ArcSWAT includes the SWAT (Soil and Water Assessment Tool, Arnold et al., 1998) model developed for the USDA Agricultural Research Service into ArcGIS (ESRI®). SWAT was developed to assess the impact of land management practices on large complex watersheds with varying soils, land use and management conditions over long periods of time (Neitsch et al., 2005). According to this, ArcSWAT would be the best option for IWRM implementation in the basin. However

  7. Minibasins and salt canopy in foreland fold-and-thrust belts: The central Sivas Basin, Turkey

    Science.gov (United States)

    Kergaravat, Charlie; Ribes, Charlotte; Legeay, Etienne; Callot, Jean-Paul; Kavak, Kaan Sevki; Ringenbach, Jean-Claude

    2016-06-01

    The Sivas Basin in the Central Anatolian Plateau (Turkey), which formed in the context of a foreland fold-and-thrust belt (FTB), exhibits a typical wall and basin (WAB) province characterized by symmetric minibasins separated by continuous steep-flanked walls and diapirs. Extensive fieldwork including regional and detailed local mapping of the contacts and margins of minibasins, and interpretation of a set of 2-D regional seismic lines, provide evidence for the development of a shallow evaporite level separating two generations of minibasins within the WAB province. Here beds of symmetric exposed minibasins along diapir flank are younger than minibasins observed over autochthonous evaporites. Laterally away from the WAB province, increase in wavelength of the tectonic structures suggests a deepening of the decollement level. We interpret that a shallower evaporite level developed in the form of an evaporite canopy, triggered by significant lateral shortening. The Upper Eocene-Lower Oligocene autochthonous Tuzhisar evaporite level was remobilized by the northward migrating sedimentary load and the tilting of the southern basin margin during propagation of the foreland fold-and-thrust belt. Asymmetric and symmetric primary minibasins were overrun by an allochthonous sheet forming a canopy. A second generation of salt withdrawal minibasins subsided into the allochthonous salt sheet. The polygonal pattern of the WAB province influences the growing fold-and-thrust belt system during the late stage of the secondary minibasins development. The Sivas FTB basin is the result of the interaction between fold-and-thrust belt propagation, evaporite remobilization, and interaction between evaporite flow and sedimentation in the minibasins.

  8. Estimates of ground-water recharge rates for two small basins in central Nevada

    International Nuclear Information System (INIS)

    Estimates of ground-water recharge rates developed from hydrologic modeling studies are presented for 3-Springs and East Stewart basins, two small basins (analog sites) located in central Nevada. The analog-site studies were conducted to aid in the estimation of recharge to the paleohydrologic regime associated with ground water in the vicinity of Yucca Mountain under wetter climatic conditions. The two analog sites are located to the north and at higher elevations than Yucca Mountain, and the prevailing (current) climatic conditions at these sites is thought to be representative of the possible range of paleoclimatic conditions in the general area of Yucca Mountain during the Quaternary. Two independent modeling approaches were conducted at each of the analog sites using observed hydrologic data on precipitation, temperature, solar radiation, stream discharge, and chloride-ion water chemistry for a 6-year study period (October 1986 through September 1992). Both models quantify the hydrologic water-balance equation and yield estimates of ground-water recharge, given appropriate input data. Results of the modeling approaches support the conclusion that reasonable estimates of average-annual recharge to ground water range from about 1 to 3 centimeters per year for 3-Springs basin (the drier site), and from about 30 to 32 centimeters per year for East Stewart basin (the wetter site). The most reliable results are those derived from a reduced form of the chloride-ion model because they reflect integrated, basinwide processes in terms of only three measured variables: precipitation amount, precipitation chemistry, and streamflow chemistry

  9. Polyphase tectonic subsidence evolution of the Vienna Basin inferred from quantitative subsidence analysis of the northern and central parts

    Science.gov (United States)

    Lee, Eun Young; Wagreich, Michael

    2016-04-01

    The Vienna Basin is a tectonically complex Neogene basin situated at the Alpine-Carpathian transition. This study analyzes a detailed quantification of subsidence in the northern and central parts of the Vienna Basin to understand its tectonic subsidence evolution. About 200 wells were used to arrange stratigraphic setting, and wells reaching the pre-Neogene basement were analyzed for subsidence. To enhance the understanding of the regional subsidences, the wells were sorted into ten groups based on their position on major fault blocks. In the Early Miocene, subsidence was slow and along E-W to NE-SW trending axis, indicating the development of thrust-controlled piggyback basins. During the late Early Miocene data show abruptly increasing subsidence, making the initiation of the Vienna pull-apart basin system. From the Middle Miocene, the tectonic subsidence curves show regionally different patterns. The tectonic subsidence during the Middle Miocene varies laterally across the Vienna Basin, and the differential subsidence can be related to the changing tensional regime of weakening transtension and strengthening extension toward the late Middle Miocene. From the late Middle Miocene to the Late Miocene, the tectonic subsidence occurred dominantly along the regional active faults, and corresponds to the axis of E-W trending extension of the western parts of the Pannonian Basin system. In the Quaternary the Vienna Basin has been reactivated, and resulted in subsidence along the NE-SW trending Vienna Basin transfer fault system.

  10. Coarse fraction components in a red-clay sedimemt core, Central Indian Ocean Basin: Their occurrence and significance

    Digital Repository Service at National Institute of Oceanography (India)

    Iyer, S.D.; Fernandes, G.Q.; Mahender, K.

    on the sediment distribution and processes responsible in the Central Indian Ocean Basin (CIOB), a basin which receives sediments from two of the large rivers in the world i.e., Ganges and Brahmaputra (Nath et al., 1989) and also holds potential ferromanganese... (FeMn) nodule deposits in the world oceans. The nature and distribution of sediments in the Indian Ocean are principally controlled by interrelated factors (cf. Mukhopadhyay et al., 2008): climatic and current patterns, nutrient and organic...

  11. Structural control of the basement in the central portion of the Santos Basin-Brazil; Controle estrutural do embasamento na porcao central da Bacia de Santos

    Energy Technology Data Exchange (ETDEWEB)

    Izeli, Maira G.B.; Morales, Norberto; Souza, Iata A. de [Universidade Estadual Paulista (UNESP), Rio Claro, SP (Brazil). Inst. de Geociencias e Ciencias Exatas

    2008-07-01

    New discoveries of oil in deep water and ultra-deep water in Santos Basin suggest that it needs to be studied to better understanding of basement structures and their role in the basin control and configuration. This study characterizes the main tectonic structures of a portion at the central area of this basin, looking for their relation to the geological basement framework. The study is based on the integration of the geological and geophysical data from subsurface (offshore) and surface of the adjacent continent. These analyses include the continental structures that continue in direction of this basin (Guapiara Lineament and Ponta Grossa Arc), checking their possible influence on the basin evolution and deformation. To achieve the proposed goals, the Precambrian basement lineaments were extracted from the offshore area using remote sensing, as result was obtained strong NW-SE structural trend. According to the interpretation of seismic sections, it is possible to observe that this portion of the basin presents main NE-SW structural trend, and most of the structures are typical of passive margin and halokintics process. It is possible to see that some recognized faults in the rift deposits may be coinciding with the main continental guidelines which are projected into the basin. (author)

  12. Dimethyl sulfide in the Amazon rain forest

    Science.gov (United States)

    Jardine, K.; Yañez-Serrano, A. M.; Williams, J.; Kunert, N.; Jardine, A.; Taylor, T.; Abrell, L.; Artaxo, P.; Guenther, A.; Hewitt, C. N.; House, E.; Florentino, A. P.; Manzi, A.; Higuchi, N.; Kesselmeier, J.; Behrendt, T.; Veres, P. R.; Derstroff, B.; Fuentes, J. D.; Martin, S. T.; Andreae, M. O.

    2015-01-01

    Surface-to-atmosphere emissions of dimethyl sulfide (DMS) may impact global climate through the formation of gaseous sulfuric acid, which can yield secondary sulfate aerosols and contribute to new particle formation. While oceans are generally considered the dominant sources of DMS, a shortage of ecosystem observations prevents an accurate analysis of terrestrial DMS sources. Using mass spectrometry, we quantified ambient DMS mixing ratios within and above a primary rainforest ecosystem in the central Amazon Basin in real-time (2010-2011) and at high vertical resolution (2013-2014). Elevated but highly variable DMS mixing ratios were observed within the canopy, showing clear evidence of a net ecosystem source to the atmosphere during both day and night in both the dry and wet seasons. Periods of high DMS mixing ratios lasting up to 8 h (up to 160 parts per trillion (ppt)) often occurred within the canopy and near the surface during many evenings and nights. Daytime gradients showed mixing ratios (up to 80 ppt) peaking near the top of the canopy as well as near the ground following a rain event. The spatial and temporal distribution of DMS suggests that ambient levels and their potential climatic impacts are dominated by local soil and plant emissions. A soil source was confirmed by measurements of DMS emission fluxes from Amazon soils as a function of temperature and soil moisture. Furthermore, light- and temperature-dependent DMS emissions were measured from seven tropical tree species. Our study has important implications for understanding terrestrial DMS sources and their role in coupled land-atmosphere climate feedbacks.

  13. Estudos etnoictiológicos sobre o pirarucu Arapaima gigas na Amazônia Central Ethnoictiology studies on Pirarucu (Arapaima mock-ups in Central Amazon

    Directory of Open Access Journals (Sweden)

    Liane Galvão de Lima

    2012-09-01

    Full Text Available O presente estudo visou identificar saberes comuns entre o conhecimento científico e o conhecimento local sobre a ecologia e biologia do pirarucu (Arapaima gigas, contribuindo com informações úteis para a implementação e consolidação de projetos de manejo participativo pesqueiro na região. Foram realizadas 57 entrevistas semi-estruturadas, com pescadores profissionais de Manaus e pescadores de subsistência de Manacapuru durante o período de junho a dezembro do ano de 2002. Foi observado que os pescadores profissionais possuem informações igualmente precisas e abrangentes em relação aos saberes dos pescadores ribeirinhos de subsistência nos aspectos de reprodução, predação, migração, crescimento e mortalidade. Os aspectos que não são equivalentes entre os pescadores profissionais comerciais citadinos e ribeirinhos de subsistência são nos aspectos de tipo de alimentação e no tamanho de recrutamento pesqueiro. Concluímos que os pescadores da Amazônia central possuem os conhecimentos necessários que possibilitam o manejo participativo do pirarucu, como um profundo saber nos aspectos comportamentais, biológicos e ecológicos desta espécie, podendo assim contribuir de fato com a participação de gestão nos recursos pesqueiros locais.Present study it aimed at to identify to know common between scientific knowledge and local knowledge on ecology and biology of pirarucu (Arapaima mock-ups, contributing with useful information for implementation and consolidation of projects of participative handling fishing boat in region. 57 half-structuralized interviews had been carried through, with fishing of Manaus and Manacapuru during period of June to December of year 2002. It was observed that professional fishermen also have accurate and comprehensive information in relation to knowledge of subsistence fishermen in coastal aspects of reproduction, predation, migration, growth and mortality. Aspects that are not equivalent

  14. The evolution of the Thuringian Syncline (Central Germany) - an interdisciplinary approach to basin reconstruction

    Science.gov (United States)

    Malz, Alexander; Beyer, Daniel; Donndorf, Stephan; Navabpour, Payman; Voigt, Thomas; Aehnelt, Michaela; Kley, Jonas

    2014-05-01

    The Thuringian Syncline is a shallow synform of mainly Triassic strata in Central Germany. In general, its lithostratigraphic units are similar to that of the North German Basin. On the top of the Paleozoic basement and Permocarboniferous red beds the evaporites of the late Permian Zechstein were deposited. The Triassic super group consists of fluvial to lacustrine sandstones, shale and evaporites of the Buntsandstein group, limestone, marls and evaporites of the marine Muschelkalk group and pelitic to sandy fluvial deposits and evaporite of the Keuper group. Some relicts of Lower Jurassic deposits still cover this succession. A number of NW-SE-trending fault zones with mostly small normal offsets characterize the recent structural configuration of the Thuringian Syncline. From regional correlations, and Lower Jurassic strata affected by normal faults, the extension most likely occurred in Late Jurassic to Early Cretaceous time. Some of these normal faults were reactivated as reverse faults during a phase of contraction in the Late Cretaceous. The unknown original offsets of the normal faults and the absence of syntectonic strata deposited during extension and contraction, however, make reconstruction of the graben inversion difficult to detect. In this study we try to reconstruct the structural evolution of the Thuringian Syncline based on structural observations, detailed map analysis, interpolations of stratigraphic surfaces at depth, cross section balancing and fault slip data analysis. Vitrinite reflectance data are used to estimate the maximum thickness of the eroded overburden. Our study identified a deep, extended and later inverted palaeo-depression in the central part of the Thuringian Syncline. We show that the recent structural configuration cannot explain variations of the thermal maturity without deriving specific thickness variations in the eroded overburden. Taking in consideration that many Central European faults, formerly interpreted as purely

  15. Study of ceramics from circular archaeological sites of Amazonic Basin by geochemical methods: dating and characterization; Estudo de ceramicas de sitios arqueologicos circulares da Bacia Amazonica por meio de metodos geoquimicos: datacao e caracterizacao

    Energy Technology Data Exchange (ETDEWEB)

    Nicoli, Ieda Gomes

    2000-09-01

    The aim of this work is to examine by means of characterization and dating pottery recently discovery inside archaeological sites recognized with circular earth structure in Acre State - Brazil which may contribute to the research in the reconstruction of part of the pre-history of the Amazonic Basin. These sites are located mainly in the Hydrographic Basin of High Purus River. Three of them were strategic chosen which provide the ceramics: Lobao, in Sena Madureira County at north; Alto Alegre, in Rio Branco County at east and Xipamanu I, in Xapuri County at south. The X-ray diffraction mineral analysis made possible to identify two types of crystal structures of ceramic minerals: quartz and M-Kaolinite. Neutron activation analysis in conjunction with multivariate statistical methods were applied for the ceramic characterization and classification. An homogeneous group was established by all sherds collected from Alto Alegre and was distinct from all the other two groups analyzed. Some of the sherds collected from Xipamanu I appeared in Lobao's urns, probably because they had the same fabrication process. The Lobao's urns presented a homogeneous group. Geochronology of these materials was carried out by Thermoluminescence. The Xipamanu I was the oldest site and Lobao the youngest. The average age of Xipamanu I and Alto Alegre were 2600 and 2070 years respectively. The average age of of occupation was 400 years to Alto Alegre and 970 years to Xipamanu I. The most probably date for Lobao was 1880 years. (author)

  16. Surface water dynamics in Amazon, Congo, and Lake Chad Wetlands from remote sensing and modeling

    Science.gov (United States)

    Jung, H.; Getirana, A.; Jasinski, M. F.

    2013-05-01

    The capability of satellites to understand and monitor surface water dynamics in tropical wetlands is presented by analysis various remote sensing technologies over the Amazon, Congo, and Lake Chad regions. Although different in size and location, all these basins are tropical, representing riparian tropical, swamp tropical and inland Saharan wetlands, respectively. First, yearly flooding in the Logone floodplain is investigated using Landsat Enhanced Thematic Mapper Plus (ETM+). Flooding has a direct impact on agricultural, pastoral and fishery systems in the Lake Chad Basin. Since the flooding extent, depth, and duration are highly variable, flood inundation mapping facilitates efficient use of water resources and have more knowledge of the coupled human-natural system in the Logone floodplain. Flood maps are generated from 33 multi-temporal ETM+ images acquired during the period 2006 to 2008. The maximum flooding extent in the study area increases up to ~5.8K km2 in late October 2008. A strong correlation is observed between the flooding extents and water height variations in both the floodplain and the river. Second, interferometric processing of JERS-1 SAR data from the central portions of both Amazon and Congo Wetlands provides centimeter-scale measurements of water level change. The Amazon is marked by a myriad of floodplain channels, but the Congo has comparatively few. Amazon floodplain channels, lakes and pans are well interconnected, whereas the Congo wetlands are expanses with few boundaries or flow routes. The hydraulic processes that build the Amazon floodplain are not similarly apparent in the Congo. Third, we evaluate the potential of large altimetry datasets as a complementary gauging network capable of providing water discharge in ungauged regions. A rating-curve-based methodology is adopted to derive water discharge from altimetric data provided by the Envisat satellite within the Amazon basin. From a global-scale perspective, the stage

  17. Seismic stratigraphy of middle Cretaceous unconformity (MCU) in central Gulf of Mexico basin

    Energy Technology Data Exchange (ETDEWEB)

    Faust, M.J.

    1986-05-01

    A widespread high-amplitude reflector seen on seismic data throughout the Gulf of Mexico has been called the middle Cretaceous unconformity (MCU). This reflector seems to be a major stratigraphic boundary in the Gulf of Mexico basin. It is believed to correspond to Vail's type 1 unconformity of middle Cenomanian age (97 Ma), which records an eustatic drop in sea level of approximately 200 m. This study area includes the entire Gulf of Mexico, except areas of thick, highly deformed salt where following the MCU with any degree of confidence becomes impossible. The MCU is easy to follow in multichannel seismic reflection profiles collected by the Institute for Geophysics of the University of Texas at Austin in the Gulf of Mexico. In central, deeper part of the gulf, reflectors above and below the MCU are parallel. In the southern and eastern rims of the gulf, along the Campeche and Florida escarpments, reflectors are truncated below the MCU and show onlap relationships above it. Therefore, the MCU may be interpreted as representing an unconformity along the southern and eastern rims of the Gulf of Mexico basin. The unconformity appears to die out and grade into a conformable section toward the center of the basin, and channeling is common along the Campeche and Florida escarpments. These channels can be projected back into canyons in the escarpments, which were probably initiated by subaerial exposure of the top of the escarpments during the middle Cretaceous lowstand. The downslope channels, being sourced by the canyons, were cut in deep water.

  18. Basin Analysis and Petroleum System Characterization and Modeling, Interior Salt Basins, Central and Eastern Gulf of Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Ernest A. Mancini; Paul Aharon; Donald A. Goddard; Roger Barnaby

    2006-05-26

    The principal research effort for Phase 1 (Concept Development) of the project has been data compilation; determination of the tectonic, depositional, burial, and thermal maturation histories of the North Louisiana Salt Basin; basin modeling (geohistory, thermal maturation, hydrocarbon expulsion); petroleum system identification; comparative basin evaluation; and resource assessment. Existing information on the North Louisiana Salt Basin has been evaluated, an electronic database has been developed, and regional cross sections have been prepared. Structure, isopach and formation lithology maps have been constructed, and burial history, thermal maturation history, and hydrocarbon expulsion profiles have been prepared. Seismic data, cross sections, subsurface maps and burial history, thermal maturation history, and hydrocarbon expulsion profiles have been used in evaluating the tectonic, depositional, burial and thermal maturation histories of the basin. Oil and gas reservoirs have been found to be associated with salt-supported anticlinal and domal features (salt pillows, turtle structures and piercement domes); with normal faulting associated with the northern basin margin and listric down-to-the-basin faults (state-line fault complex) and faulted salt features; and with combination structural and stratigraphic features (Sabine and Monroe Uplifts) and monoclinal features with lithologic variations. Petroleum reservoirs include Upper Jurassic and Cretaceous fluvial-deltaic sandstone facies; shoreline, marine bar and shallow shelf sandstone facies; and carbonate shoal, shelf and reef facies. Cretaceous unconformities significantly contribute to the hydrocarbon trapping mechanism capacity in the North Louisiana Salt Basin. The chief petroleum source rock in this basin is Upper Jurassic Smackover lime mudstone beds. The generation of hydrocarbons from Smackover lime mudstone was initiated during the Early Cretaceous and continued into the Tertiary. Hydrocarbon

  19. Water resources in the Big Lost River Basin, south-central Idaho

    Science.gov (United States)

    Crosthwaite, E.G.; Thomas, C.A.; Dyer, K.L.

    1970-01-01

    The Big Lost River basin occupies about 1,400 square miles in south-central Idaho and drains to the Snake River Plain. The economy in the area is based on irrigation agriculture and stockraising. The basin is underlain by a diverse-assemblage of rocks which range, in age from Precambrian to Holocene. The assemblage is divided into five groups on the basis of their hydrologic characteristics. Carbonate rocks, noncarbonate rocks, cemented alluvial deposits, unconsolidated alluvial deposits, and basalt. The principal aquifer is unconsolidated alluvial fill that is several thousand feet thick in the main valley. The carbonate rocks are the major bedrock aquifer. They absorb a significant amount of precipitation and, in places, are very permeable as evidenced by large springs discharging from or near exposures of carbonate rocks. Only the alluvium, carbonate rock and locally the basalt yield significant amounts of water. A total of about 67,000 acres is irrigated with water diverted from the Big Lost River. The annual flow of the river is highly variable and water-supply deficiencies are common. About 1 out of every 2 years is considered a drought year. In the period 1955-68, about 175 irrigation wells were drilled to provide a supplemental water supply to land irrigated from the canal system and to irrigate an additional 8,500 acres of new land. Average. annual precipitation ranged from 8 inches on the valley floor to about 50 inches at some higher elevations during the base period 1944-68. The estimated water yield of the Big Lost River basin averaged 650 cfs (cubic feet per second) for the base period. Of this amount, 150 cfs was transpired by crops, 75 cfs left the basin as streamflow, and 425 cfs left as ground-water flow. A map of precipitation and estimated values of evapotranspiration were used to construct a water-yield map. A distinctive feature of the Big Lost River basin, is the large interchange of water from surface streams into the ground and from the

  20. Hydrologic Setting and Conceptual Hydrologic Model of the Walker River Basin, West-Central Nevada

    Science.gov (United States)

    Lopes, Thomas J.; Allander, Kip K.

    2009-01-01

    The Walker River is the main source of inflow to Walker Lake, a closed-basin lake in west-central Nevada. Between 1882 and 2008, agricultural diversions resulted in a lake-level decline of more than 150 feet and storage loss of 7,400,000 acre-ft. Evaporative concentration increased dissolved solids from 2,500 to 17,000 milligrams per liter. The increase in salinity threatens the survival of the Lahontan cutthroat trout, a native species listed as threatened under the Endangered Species Act. This report describes the hydrologic setting of the Walker River basin and a conceptual hydrologic model of the relations among streams, groundwater, and Walker Lake with emphasis on the lower Walker River basin from Wabuska to Hawthorne, Nevada. The Walker River basin is about 3,950 square miles and straddles the California-Nevada border. Most streamflow originates as snowmelt in the Sierra Nevada. Spring runoff from the Sierra Nevada typically reaches its peak during late May to early June with as much as 2,800 cubic feet per second in the Walker River near Wabuska. Typically, 3 to 4 consecutive years of below average streamflow are followed by 1 or 2 years of average or above average streamflow. Mountain ranges are comprised of consolidated rocks with low hydraulic conductivities, but consolidated rocks transmit water where fractured. Unconsolidated sediments include fluvial deposits along the active channel of the Walker River, valley floors, alluvial slopes, and a playa. Sand and gravel deposited by the Walker River likely are discontinuous strata throughout the valley floor. Thick clay strata likely were deposited in Pleistocene Lake Lahontan and are horizontally continuous, except where strata have been eroded by the Walker River. At Walker Lake, sediments mostly are clay interbedded with alluvial slope, fluvial, and deltaic deposits along the lake margins. Coarse sediments form a multilayered, confined-aquifer system that could extend several miles from the shoreline

  1. Quaternary Geology and Geomorphology of Terna River Basin in West Central India

    Directory of Open Access Journals (Sweden)

    Mohammad Babar

    2012-12-01

    Full Text Available This paper presents the morphostratigraphy, lithostratigraphy and sedimentary structures of Terna River basin in the Deccan Basaltic Province (DBP of West Central India. These Quaternary deposits have been divided into three informal formations (i dark grey silt formation – Late Holocene, (ii Light grey silt formations – Early Holocene, (iii Dark grayish brown silt formation – Late Pleistocene with the older Quaternary Alluvial deposits of Upper Pleistocene age. The fine clay and silt formations in the lower reaches reflect that the streams are of low gradient and more sinuous. The river shows evidences of channel movement by avulsion, largely controlled by lineaments. Palaeo-levees, in the form 4–5 m high ridges exist along the Terna River floodplain, specifically in the Ter, Killari, Sastur, Dhuta and Makni villages. Several lineaments occur along NE-SW, NW-SE, E-W and WNW-ESE directions, which control the basement structure in the study area. The values of the Topographic Sinuosity Index (TSI indicate rejuvenation of the area leading to the dominance of topography on the sinuosity of the river channels. The break in slope in the long profile is also indication of the Quaternary tectonic uplift of the area. Radiocarbon dating of some charcoal fragments collected from folded beddings indicates that paleoseismic activity might have taken place along the basin between AD 120 and AD 1671.

  2. Magnetic anomalies across Bastar craton and Pranhita–Godavari basin in south of central India

    Indian Academy of Sciences (India)

    I V Radhakrishna Murthy; S Bangaru Babu

    2009-02-01

    Aeromagnetic anomalies over Bastar craton and Pranhita –Godavari (P –G)basin in the south of central India could be attributed to NW –SE striking mafic intrusives in both the areas at variable depths.Such intrusions can be explained considering the collision of the Bastar and Dharwar cratons by the end of the Archaean and the development of tensile regimes that followed in the Paleoproterozoic,facilitating intrusions of mafic dykes into the continental crust.The P –G basin area,being a zone of crustal weakness along the contact of the Bastar and Dharwar cratons, also experienced extensional tectonics.The inferred remanent magnetization of these dykes dips upwards and it is such that the dykes are oriented towards the east of the magnetic north at the time of their formation compared to their present NW –SE strike.Assuming that there was no imprint of magnetization of a later date,it is concluded that the Indian plate was located in the southern hemisphere,either independently or as part of a supercontinent,for some span of time during Paleoproterozoic and was involved in complex path of movement and rotation subsequently. The paper presents a case study of the utility of aeromagnetic anomalies in qualitatively deducing the palaeopositions of the landmasses from the interpreted remanent magnetism of buried intrusive bodies.

  3. Correlation of the oldest Toba Tuff to sediments in the central Indian Ocean Basin

    Indian Academy of Sciences (India)

    J N Pattan; M Shyam Prasad; E V S S K Babu

    2010-08-01

    We have identified an ash layer in association with Australasian microtektites of ∼0.77Ma old in two sediment cores which are ∼450 km apart in the central Indian Ocean Basin (CIOB). Morphology and chemical composition of glass shards and associated microtektites have been used to trace their provenance. In ODP site 758 from Ninetyeast Ridge, ash layer-D (13 cm thick, 0.73–0.75 Ma) and layer-E (5 cm thick, 0.77–0.78 Ma) were previously correlated to the oldest Toba Tuff (OTT) eruptions of the Toba caldera, Sumatra. In this investigation, we found tephra ∼3100 km to the southwest of Toba caldera that is chemically identical to layer D of ODP site 758 and ash in the South China Sea correlated to the OTT. Layer E is not present in the CIOB or other ocean basins. The occurrence of tephra correlating to layer D suggests a widespread distribution of OTT tephra (∼3.6 × 107 km2), an ash volume of at least ∼1800 km3, a total OTT volume of 2300 km3, and classification of the OTT eruption as a super-eruption.

  4. Jinning granodiorite and diorite deeply concealed in the central Tarim Basin

    Institute of Scientific and Technical Information of China (English)

    LI; Yuejun; SONG; Wenjie; WU; Genyao; WANG; Yifen; LI; Yupi

    2005-01-01

    The 7200-m-deep Well Tacan 1 in the central Tarim Basin is the deepest in China. Purplish gray medium-grained granodiorite containing dark gray fine-grained diorite xenolith is revealed at the base of the well (7169―7200 m), and they are results of the Jinning magmatic activities. Trace-element geochemistry and REE profiles of both rock types are similar, indicating that they are calc-alkaline series I-type granitoid. Proxies of diorite signify the development of a magmatic arc due to subduction at ca. 1200 Ma. The granodiorite was formed before 890―932 Ma. However, more study is needed to clarify if the arc diorite represents a ca. 300 Ma extension of the subduction or a reactivation during the orogenic collision event at ca. 900 Ma.

  5. Group classification of mixed oils in central Junggar Basin, Northwest China and their migration

    Institute of Scientific and Technical Information of China (English)

    WANG Xulong; SHI Xinpu; CAO Jian; LAN Wenfang; TAO Guoliang; HU Wenxuan; YAO Suping

    2010-01-01

    The produced oils in central Junggar Basin are commonly mixed in origin. In this paper, in order to reveal this complexity and thereby provide valuable clues to the study of oil source and formation mechanism, genetic groups of the mixed oils were classified and their migration/accumulation was investigated. Based on the artificial oil mixing experiments, some representative biomarkers of the mixed oils showed varying tendencies according to mixing ratios of the oils. Hence, these biomarkers are useful for determining the origin of the mixed oils. According to the criteria, oils in the area were divided into four basic groups, i.e., the Lower Permian Fengcheng oil, the Middle Permian Lower Wuerhe oil, the Jurassic source derived oil, and the mixed oil (including the Lower and Middle Permian mixed oil and the Permian and Jurassic mixed oil). Oil migration and accumulation were discussed in combination with the geological background.

  6. Wet and dry nitrogen deposition in the central Sichuan Basin of China

    Science.gov (United States)

    Kuang, Fuhong; Liu, Xuejun; Zhu, Bo; Shen, Jianlin; Pan, Yuepeng; Su, Minmin; Goulding, Keith

    2016-10-01

    Reactive nitrogen (Nr) plays a key role in the atmospheric environment and its deposition has induced large negative impacts on ecosystem health and services. Five-year continuous in-situ monitoring of N deposition, including wet (total nitrogen (WTN), total dissolved nitrogen (WTDN), dissolved organic nitrogen (WDON), ammonium nitrogen (WAN) and nitrate nitrogen (WNN)) and dry (DNH3, DHNO3, DpNH4+, DpNO3- and DNO2) deposition, had been conducted since August 2008 to December 2013 (wet) and May 2011 to December 2013 (dry) in Yan-ting, China, a typical agricultural area in the central Sichuan Basin. Mean annual total N deposition from 2011 to 2013 was 30.8 kg N ha-1 yr-1, and speculated that of 2009 and 2010 was averaged 28.2 kg N ha-1 yr-1, respectively. Wet and dry N deposition accounted for 76.3% and 23.7% of annual N deposition, respectively. Reduced N (WAN, DNH3 and DpNH4+) was 1.7 times of oxidized N (WNN, DHNO3, DNO2 and DpNO3-) which accounted for 50.9% and 30.3% of TN, respectively. Maximum loadings of all N forms of wet deposition, gaseous NH3, HNO3 and particulate NH4+ in dry deposition occurred in summer and minimum loadings in winter. Whether monthly, seasonal or annual averaged, dissolved N accounted for more than 70% of the total. N deposition in the central Sichuan Basin increased during the sampling period, especially that of ammonium compounds, and has become a serious threat to local aquatic ecosystems, the surrounding forest and other natural or semi-natural ecosystems in the upper reaches of the Yangtze River.

  7. Interpretation of seismic reflection data, Central Palo Duro Basin: Technical report

    International Nuclear Information System (INIS)

    Seismic reflection data from the Central Palo Duro Basin, Texas, were studied to identify and characterize geologic structure, potential hydrocarbon traps, and anomalies suggesting adverse features such as salt dissolution or diapirism. The data included seismic reflection data, geologic and geophysical data controlled by Stone and Webster Engineering Corporation, and data from the literature. These data comprised approximately 590 line-mi of seismic profiles over approximately 4000 mi2, plus well logs from 308 wells. The study addressed the section from shallow reflectors down to basement. Structural contour maps were prepared for the Upper San Andres, Near Top of Glorieta, Wolfcamp, and Precambrian horizons. Isopach maps were prepared for intervals between the Upper and Lower San Andres and between the Upper San Andres and the Wolfcamp. Interpretation indicates southeasterly dips in the northwest part of the mapped area and southwesterly dips in the southwest part. Geologic structures show a generally northwest alignment. Faults at the Precambrian level and geologic structures show a generally northwest alignment. Faulting in the area is largely limited to the Precambrian, but interpretation is uncertain. Evidence of post-Wolfcampian faulting is not recognized. Seismic data delineating the San Andres section indicate a stable section throughout the area. Anomalous reflection events possibly associated with subsurface salt dissolution were seen at the 800- to 1200-ft level in Swisher County. Other anomalies include an overthickened zone northwest of Westway and carbonate buildup in the Wolfcamp and Pennsylvanian in Randall County. Mississippian to Middle Pennsylvanian diastrophism resulting in the Amarillo Uplift and Matador Arch is not manifested structurally in the central Palo Duro Basin. Subsidence or gentle uplift contributed to some structural deformation

  8. Leaf traits and gas exchange in saplings of native tree species in the Central Amazon Características foliares e trocas gasosas em arvoretas de espécies nativas da Amazônia Central

    Directory of Open Access Journals (Sweden)

    Keila Rego Mendes

    2010-12-01

    Full Text Available Global climate models predict changes on the length of the dry season in the Amazon which may affect tree physiology. The aims of this work were to determine the effect of the rainfall regime and fraction of sky visible (FSV at the forest understory on leaf traits and gas exchange of ten rainforest tree species in the Central Amazon, Brazil. We also examined the relationship between specific leaf area (SLA, leaf thickness (LT, and leaf nitrogen content on photosynthetic parameters. Data were collected in January (rainy season and August (dry season of 2008. A diurnal pattern was observed for light saturated photosynthesis (Amax and stomatal conductance (g s, and irrespective of species, Amax was lower in the dry season. However, no effect of the rainfall regime was observed on g s nor on the photosynthetic capacity (Apot, measured at saturating [CO2]. Apot and leaf thickness increased with FSV, the converse was true for the FSV-SLA relationship. Also, a positive relationship was observed between Apot per unit leaf area and leaf nitrogen content, and between Apot per unit mass and SLA. Although the rainfall regime only slightly affects soil moisture, photosynthetic traits seem to be responsive to rainfall-related environmental factors, which eventually lead to an effect on Amax. Finally, we report that little variation in FSV seems to affect leaf physiology (Apot and leaf anatomy (leaf thickness.Os modelos climáticos globais prevêem mudanças na extensão da época seca na Amazônia, o que pode afetar a fisiologia das árvores. Os objetivos deste trabalho foram determinar o efeito da sazonalidade da precipitação e fração de céu visível (FSV no sub-bosque da floresta nas características foliares e trocas gasosas de 10 espécies florestais da Amazônia Central. Também examinou-se a relação entre área foliar específica (SLA, espessura da folha (LT e nitrogênio foliar em parâmetros fotossintéticos. Os resultados foram coletados nos

  9. BASIN ANALYSIS AND PETROLEUM SYSTEM CHARACTERIZATION AND MODELING, INTERIOR SALT BASINS, CENTRAL AND EASTERN GULF OF MEXICO

    Energy Technology Data Exchange (ETDEWEB)

    Ernest A. Mancini; Donald A. Goddard; Ronald K. Zimmerman

    2005-05-10

    The principal research effort for Year 2 of the project has been data compilation and the determination of the burial and thermal maturation histories of the North Louisiana Salt Basin and basin modeling and petroleum system identification. In the first nine (9) months of Year 2, the research focus was on the determination of the burial and thermal maturation histories, and during the remainder of the year the emphasis has basin modeling and petroleum system identification. Existing information on the North Louisiana Salt Basin has been evaluated, an electronic database has been developed, regional cross sections have been prepared, structure and isopach maps have been constructed, and burial history, thermal maturation history and hydrocarbon expulsion profiles have been prepared. Seismic data, cross sections, subsurface maps and related profiles have been used in evaluating the tectonic, depositional, burial and thermal maturation histories of the basin. Oil and gas reservoirs have been found to be associated with salt-supported anticlinal and domal features (salt pillows, turtle structures and piercement domes); with normal faulting associated with the northern basin margin and listric down-to-the-basin faults (state-line fault complex) and faulted salt features; and with combination structural and stratigraphic features (Sabine and Monroe Uplifts) and monoclinal features with lithologic variations. Petroleum reservoirs are mainly Upper Jurassic and Lower Cretaceous fluvial-deltaic sandstone facies and Lower Cretaceous and Upper Cretaceous shoreline, marine bar and shallow shelf sandstone facies. Cretaceous unconformities significantly contribute to the hydrocarbon trapping mechanism capacity in the North Louisiana Salt Basin. The chief petroleum source rock in this basin is Upper Jurassic Smackover lime mudstone beds. The generation of hydrocarbons from Smackover lime mudstone was initiated during the Early Cretaceous and continued into the Tertiary

  10. Basin Analysis and Petroleum System Characterization and Modeling, Interior Salt Basins, Central and Eastern Gulf of Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Ernest A. Mancini

    2005-03-31

    The principal research effort for Year 2 of the project is the determination of the burial and thermal maturation histories and basin modeling and petroleum system identification of the North Louisiana Salt Basin. In the first six (6) to nine (9) months of Year 2, the research focus is on the determination of the burial and thermal maturation histories and the remainder of the year the emphasis is on basin modeling and petroleum system identification. No major problems have been encountered to date, and the project is on schedule.

  11. BASIN ANALYSIS AND PETROLEUM SYSTEM CHARACTERIZATION AND MODELING, INTERIOR SALT BASINS, CENTRAL AND EASTERN GULF OF MEXICO

    Energy Technology Data Exchange (ETDEWEB)

    Ernest A. Mancini

    2004-11-05

    The principal research effort for Year 2 of the project is the determination of the burial and thermal maturation histories and basin modeling and petroleum system identification of the North Louisiana Salt Basin. In the first six (6) to nine (9) months of Year 2, the research focus is on the determination of the burial and thermal maturation histories and the remainder of the year the emphasis is on basin modeling and petroleum system identification. No major problems have been encountered to date, and the project is on schedule.

  12. Extensional Basins in a Convergent Margin: Oligocene-Early Miocene Salar de Atacama and Calama basins, Central Andes

    Science.gov (United States)

    Jordan, T. E.; Mpodozis, C.; Blanco, N.; Pananont, P.; Dávila, F.

    2004-12-01

    The Salar de Atacama Basin (SdAB) is the largest and most persistent sedimentary basin of northern Chile, accumulating nonmarine sediment from Cretaceous to modern times. Its northwestern neighbor, the Calama, was a Cenozoic basin. Although SdAB was in the backarc zone early in the Andean orogeny, both are now forearc basins. Others demonstrated that the basins overlie anomalously cold, strong, and dense crust and lithosphere. We focus on an extensional Oligocene basin stage. Interpretation of the basin-controlling faults is based on seismic reflection studies supported by field relations. The SdAB is limited to the west by the NNE-trending, steeply east-dipping, Paciencia Fault (PF). The PF experienced 5-7 km of down-to-the-east offset during the Oligocene-early Miocene. Syntectonic strata, an arid succession of siliciclastics and evaporites, are asymmetric, with thicknesses of 5000 m and abundant halite adjacent to the PF, and of 1000 m with fine detrital clastic strata 25 km farther east. Relations in conglomeratic growth strata that overlap the PF also demonstrate normal displacement during sediment accumulation. Seismic data reveal that a buried normal fault with 1-1.5 km down-to-the-east displacement limits the western margin of the Oligocene-Miocene Calama siliciclastic basin fill. Regionally, Oligocene-early Miocene margin-parallel strike-slip deformation dominated northwest of the basins, contributing sinistral offset (West Fissure Fault) to the northern segment of the long-lived Domeyko Fault System. The new SdAB and Calama data reveal that a 20,000 km2 domain of extensional basins existed within the dominantly strike-slip region. Even if PF and the fault in the Calama Basin were transtensional, the proportion of extension to strike-slip displacement is much greater in these basins than elsewhere in northern Chile. Further study is required to understand what combination of factors caused this kinematic distinction as well as delayed the onset of CVZ

  13. Implementation of MAR within the Rio Grande Basin of Central New Mexico, USA

    Science.gov (United States)

    Marley, Robert; Blandford, T. Neil; Ewing, Amy; Webb, Larry; Yuhas, Katherine

    2014-05-01

    The U.S. Bureau of Reclamation has identified the Rio Grande basin within Central New Mexico as one of several regions where water supplies are over-allocated and future conflicts over the inadequate resource are highly likely. Local water providers have consistently identified managed aquifer recharge (MAR) as an important tool to provide conjunctive management of surface-water, groundwater, and reclaimed water sources in order to extend the useful life of existing water sources. However, MAR projects have been slow to take root partly due to rigorous demonstration requirements, groundwater quality protection concerns, and ongoing water right uncertainties. At first glance the several thousand meters of unconsolidated basin-fill sediments hosting the regional aquifer appear to provide an ideal environment for the subsurface storage of surplus water. However, the basin has a complex structural and depositional history that impacts the siting and overall effectiveness of MAR systems. Several recharge projects are now in various stages of implementation and are overcoming site specific challenges including source water and ambient groundwater compatibility, low-permeability sediments and compartmentalization of the aquifer by extensive faulting, well clogging, and overall water quality management. This presentation will highlight ongoing efforts of these water providers to develop full-scale recharge facilities. The performance of natural in-channel infiltration, engineered infiltration galleries, and direct injection systems designed to introduce from 500 to 5,000 mega-liters per annum to target intervals present from 150 to 600 meters below ground surface will be described. Source waters for recharge operations include inter-basin transferred surface water and highly treated reclaimed water sources requiring from minor to extensive treatment pre-recharge and post-recovery. Operational complexities have raised concerns related to long-term operation and maintenance

  14. Latest Permian to Middle Triassic cyclo-magnetostratigraphy from the Central European Basin, Germany: Implications for the geomagnetic polarity timescale

    OpenAIRE

    Michael Szurlies

    2007-01-01

    In Central Germany, the about 1 km thick mainly clastic Germanic Lower Triassic (Buntsandstein) consists of about 60 sedimentary cycles, which are considered to reflect variability in precipitation within the epicontinental Central European Basin, most probably due to solar-induced short eccentricity cycles. They provide a high-resolution cyclostratigraphic framework that constitutes the base for creating a composite geomagnetic polarity record, in which this paper presents a Middle Buntsands...

  15. Gravity modeling constraints on the Gatun-Chagres Basin and tectonic evolution of north-central Panama

    Science.gov (United States)

    Mynhier, Kelci

    The Oligocene-Miocene collision between Panama and South America significantly influenced ocean currents, global climate, and species diversification. Intraplate deformation of the Panama Block also played an important role in the evolution of this tectonic system, but is not well understood. A high-resolution gravity survey, coupled with geologic observations, was conducted in north-central Panama to better constrain the processes responsible for the Isthmus' modern configuration. Approximately 110 gravity stations were collected from Colon to Nombre de Dios, Panama and merged with existing data. Subsequently, four 2.5-D gravity models were produced to constrain the geometry of the Gatun-Chagres Basin using different sedimentary densities (1.8, 2.0, and 2.2 g/cm 3) to produce a realistic range of basin thicknesses. Overall, models with an average basin density of 2.0 g/cm3 are most consistent with offshore seismic profiles and field evidence, suggesting basin thickness is ~3.0--3.5 km. Previous seismic reflection data and geochemical analyses of Miocene arc volcanic rocks delineate a zone of extension in the Panama Canal Region, and gravity analysis from this study supports this hypothesis. Field evidence of multiple NW-facing normal faults suggests that they separate the basin from uplifted arc basement rocks east of the Canal, resulting in a 60 mGal gravity gradient. Beneath the basin, gravity models indicate ~5--10 km of crustal thinning. 3-D reconstruction of the 2.5-D models show a northward thickening basin and two depocenters that correspond to the Rio Indio and Toro facies of the Chagres Formation. This analysis suggests two directional extension of the Gatun-Chagres Basin; an east-west direction corresponding to the initial formation of the basin, and a modern northwest-southeast direction. To the northeast, gravity modeling indicates that there is a ~150 m-thick, Cretaceous-Holocene sedimentary basin present from Portobelo to Nombre de Dios. Sedimentary

  16. Microbial biomass and organic nutrients in the deep-sea sediments of the Central Indian Ocean Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Raghukumar, C.; Sheelu, G.; LokaBharathi, P.A.; Nair, S.; Mohandass, C.

    ChandralataRaghukumar,NationalInstituteofOceano-graphy,DonaPaula,Goa403004,India.E-mail:lata@csnio.ren.nic.inorlata@darya.nio.org InordertoassessthepotentialenvironmentalimpactofmanganesenodulesminingintheCentralIndianOceanBasin(CIOB),theAreaA1waschosenasthesiteforcarryingoutbaselinestudiesofthebiological....Maltextractagarof1=5strengthpreparedwithseawatercontaining0.05g streptomycinand10,000unitsofpenicillin/100mlofmediumtoinhibitbacterialgrowthforisolatingfungiandyeasts.Tworeplicatesweremaintainedforalltheaboveisolations.Afterincubationsfor 7±10days,at208§28...

  17. Depositional history and clay minerals of the Upper Cretaceous basin in the South-Central Pyrenees, Spain

    NARCIS (Netherlands)

    Nagtegaal, P.J.C.

    1972-01-01

    An ordered sequence of well-defined sedimentary environments reflects the deepening and shallowing stages in the depositional history of the Upper Cretaceous basin in the South-Central Pyrenees, Spain. The sequence, which has a Santonian age at its base, starts with a calcarenite barrier system on w

  18. A note on chemical composition and origin of ferromanganese oxide coated and uncoated pumice samples from central Indian Ocean basin

    Digital Repository Service at National Institute of Oceanography (India)

    Pattan, J.N.; Parthiban, G.; Moraes, C.; Rajalakshmi, R.; Lekshmi, S.; Athira, S.; JaiSankar, S.

    version: J. Geol. Soc. India, vol.87(1); 2016; 62-68 A note on Chemical Composition and Origin of Ferromanganese Oxide Coated and Uncoated Pumice samples from Central Indian Ocean Basin J. N. PATTAN1*, G. PARTHIBAN1, C. MORAES1, R...

  19. The ant (Hymenoptera: Formicidae) fauna of the cedar glades and xeric limestone prairies of the Central Basin of Tennessee

    Science.gov (United States)

    Ants may be the most thoroughly documented group of insects inhabiting the cedar glades of the Central Basin of Tennessee with two studies conducted in the late 1930s reporting ants found in cedar glades of the region. To compare the ant fauna of modern cedar glades with the lists produced in earlie...

  20. 利用重力卫星GRACE监测亚马逊流域2002-2010年的陆地水变化%Terrestrial water storage changes in the Amazon basin measured by GRACE during 2002-2010

    Institute of Scientific and Technical Information of China (English)

    冯伟; Jean-Michel LEMOINE; 钟敏; 许厚泽

    2012-01-01

    We estimate the terrestrial water storage (TWS) changes in the Amazon basin using GRACE, and compare the results with that of hydrological models and precipitation data. On inter-annual timescales, GRACE results show obvious drought events in 2002-2003 and 2005. From 2007 to 2009, TWS shows a significant increase, and reaches the maximum (772±181 km3) in June 2009. From June 2009 to December 2010, TWS reduces 1139±262 km3, which is equivalent to 3. 2 ±0. 7 mm global sea level rise. Results from hydrological models also show an obvious TWS decrease in 2010, which are consistent with GRACE's results. In drought seasons of 2005 and 2010, the precipitation in the Amazon basin decreases significantly, which indicates that the precipitation is a key factor of TWS changes. In addition, the scaling factor method we used in this study reduces GRACE post-process errors in the Amazon basin significantly.%本文利用GRACE (Gravity Recovery and Climate Experiment)卫星重力资料研究了亚马逊流域2002-2010年的陆地水变化,并与水文模式和降雨资料进行了比较分析.在年际尺度上,GRACE结果表明:2002-2003年和2005年,亚马逊流域发生明显的干旱现象;2007年至2009年,陆地水呈逐年增加的趋势,并在2009年6月变化值达到最大,为772±181 km3;自2009年6月至2010年12月,陆地水总量又急剧减少了1139±262 km3,这相当于全球海平面上升3.2±0.7 mm所需的水量.水文模式得到的亚马逊流域陆地水在2010年也表现出明显的减少.降雨资料与GRACE观测资料有很好的一致性.在2005年和2010年的干旱期,亚马逊流域的降雨显著减少,说明降雨是亚马逊流域陆地水变化的重要因素.此外,本文采用的尺度因子的方法有效地降低了GRACE后处理误差的影响.

  1. New species of Moenkhausia Eigenmann (Ostariophysi: Characidae from the upper rio Tocantins basin in Central Brazil

    Directory of Open Access Journals (Sweden)

    Vinicius A Bertaco

    2011-03-01

    Full Text Available Moenkhausia dasalmas is described from the upper rio Tocantins basin, in the Chapada dos Veadeiros region, Goiás State, Central Brazil. The new species differs from all congeners by the presence of iii,9 rays in the dorsal fin. It can also be distinguished from its congeners by the presence of two humeral spots (first one vertically elongate and second one faint, by the number of branched anal-fin rays (17-19, lateral line scales (36-37, maxillary teeth (4-5, and a vertical dark spot in the caudal peduncle end.Moenkhausia dasalmas é descrita da bacia do alto rio Tocantins, Chapada dos Veadeiros, Goiás, Brasil Central. A espécie nova difere de todas as suas congêneres pela presença de iii,9 raios na nadadeira dorsal. Ela também se distingue das suas congêneres por apresentar duas manchas umerais (a primeira verticalmente alongada e a segunda tênue, 17-19 raios ramificados na nadadeira anal, 36-37 escamas na linha lateral, quatro a cinco dentes no maxilar e uma mancha vertical e escura no final do pedúnculo caudal.

  2. Molecular markers in ambient aerosol in the Mahanadi Riverside Basin of eastern central India during winter.

    Science.gov (United States)

    Nirmalkar, Jayant; Deb, Manas K; Deshmukh, Dhananjay K; Tsai, Ying I; Verma, Santosh K

    2015-01-01

    Organic molecular markers are important atmospheric constituents. Their formation and sources are important aspects of the study of urban and rural air quality. We collected PM10 aerosol samples from the Mahanadi Riverside Basin (MRB), a rural part of eastern central India, during the winter of 2011. PM10 aerosols were characterized for molecular markers using ion chromatography. The concentration of PM10 ranged from 208.8 to 588.3 μg m(-3) with a mean concentration of 388.9 μg m(-3). Total concentration of anhydrosugars, sugar alcohols, primary sugars, and oxalate were found to be 3.25, 5.60, 10.52, and 0.37 μg m(-3), respectively, during the study period. Glucose was the most abundant species followed by levoglucosan and mannitol. Significant positive correlation between the molecular markers, anhydrosugars, sugar alcohols, primary sugars, and oxalic acid confirmed that biomass burning, biogenic activity, and re-suspension of soil particles were the main sources of aerosol in the eastern central India study area. PMID:25131681

  3. Amazon soils : a reconnaissance of the soils of the Brazilian Amazon region

    NARCIS (Netherlands)

    Sombroek, W.G.

    1966-01-01

    The study deals with soils of the Brazilian part of the Amazon basin. Most soils are Latosols, some with soft or hardened plinthite. The Latosols are characterized by a latosolic B horizon as defined in Brazil.Plinthite, its formation and morphology were extensively described. Five main types of har

  4. Extension of geographic distribution of Chrysobrycon hesperus and C. myersi (Characiformes, Characidae, Stevardiinae for several drainages flowing into the Amazon River Basin in Peru and Colombia Extensión de la distribución geográfica de Chrysobrycon hesperus y C. myersi (Characiformes, Characidae, Stevardiinae para varios drenajes fluyendo hacia la cuenca del Amazonas en Perú y Colombia

    Directory of Open Access Journals (Sweden)

    James Anyelo Vanegas-Ríos

    2013-03-01

    Full Text Available The geographic distribution of Chrysobrycon hesperus (Böhlke and C. myersi Weitzman and Menezes is extended to new localities from the upper Amazon Basin in Peru and Colombia. Chrysobrycon hesperus is recorded for the first time for the Putumayo River Basin in Colombia.Se amplía la distribución geográfica de Chrysobrycon hesperus (Böhlke y C. myersi Weitzman y Menezes para nuevas localidades de la cuenca alta del Amazonas en Perú y Colombia. Chrysobrycon hesperus se registra por primera vez para la cuenca del río Putumayo en Colombia.

  5. La géochimie organique des sédiments marins profonds, mission orgon 2, 1975 (Bassin de Cariaco et cône de l'Amazone Organic Geochemistry of Deep Marine Sediments. Orgon 2 Mission, 1975 (Cariaco Basin and Amazon Fan

    Directory of Open Access Journals (Sweden)

    Pelet R.

    2006-11-01

    opposition between the Cariaco Basin, which is on anoxic environment rich in microflora and especially in sulfate-reducing bacteria, and the Demerara Plain and Amazon Fan where the water contains only mediocre amounts of microflora and the sediments contain even fewer amounts thon the water (a phenomenon that never exists in coastal or shallow water. A direct relationship is revealed between the microflore content and the rate of sedimentation, thus giving a coherent picture of the findings obtained by both ORLON I and ORLON 2. In the field of the biochemisiry of the water, in addition ta the water overlying the sediments, an analysis was also made of the interstitial water from 95 sedimentary levels of the cores. The use of a special core cutter on cores token with a short Reineck corer enabled a thorough analysis to be made of the physical parometers (pH, Eh and the chemical constituents (dissolved Oz, dissolved 5--, PO4--, NH4 and alkalinity of the interstitiel water.

  6. Determinação de idade e crescimento do mapará (Hypophthalmus marginatus na Amazônia Central Age and growth of mapará (Hypophthalmus marginatus in the Central Amazon

    Directory of Open Access Journals (Sweden)

    Leocy Cutrim

    2005-01-01

    Full Text Available O presente trabalho visa contribuir para a conservação e manejo do mapará (Hypophthalmus marginatus, um importante recurso pesqueiro de exportação do Amazonas para o qual é necessário conhecer informações essenciais de sua dinâmica de populações. Para contribuir à esta finalidade, o presente trabalho estabeleceu como objetivo identificar o par de otólito mais adequado para leitura de anéis etários, determinar os parâmetros de crescimento do mapará (H. marginatus, Amazônia Central, Amazonas - Brasil. O trabalho foi efetuado através da análise de otólitos coletados no período de dezembro de 1996 á agosto de 1997. Os otólitos escolhidos foram os asteriscus, sendo a leitura efetuada em lupa estereoscópica com monitor acoplado. As marcas de crescimento foram validadas por meio da análise do incremento marginal relativo, sendo encontrado dois anéis/ano. Os valores estimados para os parâmetros no período foram L¥ = 52,63 cm; k = 0,555 ano; to = -0,029 e M = 0,552. O ciclo hidrológico e comportamento reprodutivo estão relacionados com a marcação de anéis etários.The present work seeks to contribute for the conservation and management of the mapará(Hypophthalmus marginatus, an important export fishing resource of Amazonas for which is necessary to know essential information of its population dynamics. To contribute to this purpose, the present work established as objective to identify a structure for reading of age rings, to determine the parameters of growth of the mapará (H. marginatus, Central Amazon, Amazonas - Brazil. The work was made through the otoliths analysis collected in the period of December of 1996 to August of 1997. The otolith chosen for reading was the asteriscus, being the reading made in a stereomicroscope with coupled monitor. The mark structures were validated by means of the analysis of the relative marginal increment, being found two rings. The values estimated for the parameters in the

  7. Modelling basin-wide variations in Amazon forest productivity – Part 1: Model calibration, evaluation and upscaling functions for canopy photosynthesis

    Directory of Open Access Journals (Sweden)

    L. M. Mercado

    2009-03-01

    Full Text Available Given the importance of Amazon rainforest in the global carbon and hydrological cycles, there is a need to parameterize and validate ecosystem gas exchange and vegetation models for this region in order to adequately simulate present and future carbon and water balances. In this study, a sun and shade canopy gas exchange model is calibrated and evaluated at five rainforest sites using eddy correlation measurements of carbon and energy fluxes.

    Results from the model-data evaluation suggest that with adequate parameterisation, photosynthesis models taking into account the separation of diffuse and direct irradiance and the dynamics of sunlit and shaded leaves can accurately represent photosynthesis in these forests. Also, stomatal conductance formulations that only take into account atmospheric demand fail to correctly simulate moisture and CO2 fluxes in forests with a pronounced dry season, particularly during afternoon conditions. Nevertheless, it is also the case that large uncertainties are associated not only with the eddy correlation data, but also with the estimates of ecosystem respiration required for model validation. To accurately simulate Gross Primary Productivity (GPP and energy partitioning the most critical parameters and model processes are the quantum yield of photosynthetic uptake, the maximum carboxylation capacity of Rubisco, and simulation of stomatal conductance.

    Using this model-data synergy, we developed scaling functions to provide estimates of canopy photosynthetic parameters for a~range of diverse forests across the Amazon region, utilising the best fitted parameter for maximum carboxylation capacity of Rubisco, and foliar nutrients (N and P for all sites.

  8. Declining fertility on the frontier: the Ecuadorian Amazon

    OpenAIRE

    Carr, David L.; Pan, William K. Y.; Bilsborrow, Richard E.

    2006-01-01

    This paper examines farm and household characteristics associated with a rapid fertility decline in a forest frontier of the Ecuadorian Amazon. The Amazon basin and other rainforests in the tropics are among the last frontiers in the ongoing global fertility transition. The pace of this transition along agricultural frontiers will likely have major implications for future forest transitions, rural development, and ultimately urbanization in frontier areas. The study here is based upon data fr...

  9. Chemical quality of water in the Walnut River basin, south-central Kansas

    Science.gov (United States)

    Leonard, Robert B.

    1972-01-01

    Improper disposal of oil-field brine and other wastes has adversely affected the naturally diverse chemical quality of much of the water in the Walnut River basin, south-central Kansas. The basin is an area of about 2,000 square miles in the shape of a rough triangle with its apex toward the south. The Whitewater River, a principal tributary, and the Walnut River below its junction with the Whitewater River flow southward toward the Arkansas River along courses nearly coincident with the contact of the Chase and overlying Sumner Groups of Permian age. The courses of many minor tributaries are parallel to a well-developed joint system in the Permian rock. Thick interbedded limestone and shale of the Chase Group underlie the more extensive, eastern part of the basin. Natural waters are dominantly of the calcium bicarbonate type. Shale and subordinate strata of limestone, gypsum, and dolomite of the Sumner Group underlie the western part of the basin. Natural waters are dominantly of the calcium sulfate type. Inflow from most east-bank tributaries dilutes streamflow of the Walnut River; west-bank tributaries, including the Whitewater River, contribute most of the sulfate. Terrace deposits and alluvial fill along the stream channels are assigned to the Pleistocene and Holocene Series. Calcium bicarbonate waters are common as a result of the dissolution of nearly ubiquitous fragments of calcareous rock, but the chemical quality of the water in the discontinuous aquifers depends mainly on the quality of local recharge. Concentrations of dissolved solids and of one or more ions in most well waters exceeded recommended maximums for drinking water. Nearly all the ground water is hard to very hard. High concentrations of sulfate characterize waters from gypsiferous aquifers; high concentrations of chloride characterize ground waters affected by drainage from oil fields. Extensive fracture and dissolution of the Permian limestones facilitated pollution of ground water by oil

  10. Diversity of palm uses in the western Amazon

    DEFF Research Database (Denmark)

    Paniagua Zambrana, N.Y.; Byg, A.; Svenning, J.-C.;

    2007-01-01

    Abstract  We used palm knowledge to understand the interaction between people and the rainforests and the factors that influence this dynamic process. We interviewed 278 informants in 12 villages in the Pastaza and Madidi areas of the western Amazon basin. Together they used 38 different palm......, the great variation in the knowledge they possess, and the fact that the differences between villages is so great, are important elements to consider when developing management plans for the sustainable use of the rainforest resources in the western Amazon. Keywords  Local knowledge - Palms - Western Amazon...

  11. Pesticides in surface water from three agricultural basins in south-central Georgia, 1993-97

    Science.gov (United States)

    Hatzell, H.H.

    1996-01-01

    Twenty-two of 43 pesticides analyzed were detected in 128 water samples collected from Tucsawhatchee Creek, the Little River, and the Withlacoochee River. These streams drain agricultural basins in south-central Georgia and were sampled from March 1993 through June 1995. Herbicides were detected more frequently than insecticides. The most frequently detected herbicides were atrazineand metolachlor and the most frequently detected insecticide was carbaryl. Pesticide concentrations in the three streams were low and did not exceed U.S. Environmental Protection Agency drinking water standards. The maximum pesticide concentration was 2.6 ug/L (micrograms per liter) for propargite, a miticide detected in only one sample. The maximum concentrations of the remaining 21 pesticides were less than 0.25 ug/L. The median concentrations were equal to the method detection limit for all pesticides except atrazine (0.008 ug/L) and metolachlor (0.012 ug/L). The ratio of herbicidedetections to nondetections was largest in the planting season, smaller in the harvest season and smallest in the fallow season for the three basins.The same pattern existed for the insecticide ratios in the Little River and the Withlacoochee River. Pairwise correlations between concentrations of atrazine and metolachlor and four parameters (discharge, and concentrations of dissolved organiccarbon, suspended organic carbon, and suspended fine sediment) were evaluated for each stream. The strongest correlations existed between metolachlor and mean daily discharge and metolachlor and fine sediment in the Withlacoochee River. The only significant correlation for the Little River was between atrazine and suspended fine sediment.

  12. A key continental archive for the last 2 Ma of climatic history of the central Mediterranean region: A pilot drilling in the Fucino Basin, central Italy

    Science.gov (United States)

    Giaccio, B.; Regattieri, E.; Zanchetta, G.; Wagner, B.; Galli, P.; Mannella, G.; Niespolo, E.; Peronace, E.; Renne, P. R.; Nomade, S.; Cavinato, G. P.; Messina, P.; Sposato, A.; Boschi, C.; Florindo, F.; Marra, F.; Sadori, L.

    2015-12-01

    An 82 m long sedimentary succession was retrieved from the Fucino Basin, the largest intermountain tectonic depression of the central Apennines. The basin hosts a succession of fine-grained lacustrine sediments (ca. 900 m-thick) possibly continuously spanning the last 2 Ma. A preliminary tephrostratigraphy study allows us to ascribe the drilled 82 m long record to the last 180 ka. Multi-proxy geochemical analyses (XRF scanning, total organic/inorganic carbon, nitrogen and sulfur, oxygen isotopes) reveal noticeable variations, which are interpreted as paleohydrological and paleoenvironmental expressions related to classical glacial-interglacial cycles from the marine isotope stage (MIS) 6 to present day. In light of the preliminary results, the Fucino sedimentary succession is likely to provide a long, continuous, sensitive, and independently dated paleoclimatic archive of the central Mediterranean area.

  13. Hydrological impact of rainwater harvesting in the Modder river basin of central South Africa

    Directory of Open Access Journals (Sweden)

    W. A. Welderufael

    2011-05-01

    Full Text Available Along the path of water flowing in a river basin are many water-related human interventions that modify the natural systems. Rainwater harvesting is one such intervention that involves harnessing of water in the upstream catchment. Increased water usage at upstream level is an issue of concern for downstream water availability to sustain ecosystem services. The upstream Modder River basin, located in a semi arid region in the central South Africa, is experiencing intermittent meteorological droughts causing water shortages for agriculture, livestock and domestic purpose. To address this problem a technique was developed for small scale farmers with the objective of harnessing rainwater for crop production. However, the hydrological impact of a wider adoption of this technique by farmers has not been well quantified. In this regard, the SWAT hydrological model was used to simulate the hydrological impact of such practices. The scenarios studied were: (1 Baseline scenario, based on the actual land use of 2000, which is dominated by pasture (combination of natural and some improved grass lands (PAST; (2 Partial conversion of Land use 2000 (PAST to conventional agriculture (Agri-CON; and (3 Partial conversion of Land use 2000 (PAST to in-field rainwater harvesting which was aimed at improving the precipitation use efficiency (Agri-IRWH.

    SWAT was calibrated using observed daily mean stream flow data of a sub-catchment (419 km2 in the study area. SWAT performed well in simulating the stream flow giving Nash and Sutcliffe (1970 efficiency index of 0.57 for the monthly stream flow calibration. The simulated water balance results showed that the highest peak mean monthly direct flow was obtained on Agri-CON land use (18 mm, followed by PAST (12 mm and Agri-IRWH land use (9 mm. These were 19 %, 13 % and 11 % of the mean annual rainfall, respectively. The Agri-IRWH scenario reduced direct flow by 38 % compared to Agri-CON. On the other

  14. Exploration for nodules in the Central Indian Ocean Basin: Past present and the future

    Digital Repository Service at National Institute of Oceanography (India)

    ShyamPrasad, M.

    was chosen out of the other basins in the Indian Ocean due to its accessibility, proximity and more importantly, the existing data bank showed this is to be the most prolific of all Indian Ocean basins for nodule occurrence....

  15. Carbon Tetrachloride Emissions from the Amazon Forest

    Science.gov (United States)

    Jardine, K.; Chambers, J. Q.; Higuchi, N.; Jardine, A. B.; Martin, S. T.; Manzi, A. O.

    2014-12-01

    As a chemically inert greenhouse gas in the troposphere with lifetimes up to 50 years but active in ozone destruction in the stratosphere, carbon tetrachloride (CCl4) plays a major role in the atmospheric chlorine budget and is widely considered strictly of anthropogenic origin deriving from numerous industrial processes and products. However, satellite remote sensing studies have shown higher concentrations at the Equator, and earlier work has suggested possible biogenic sources. Here we present highly vertically-resolved atmospheric gradients of CCl4 within and above a primary rainforest ecosystem from three towers in the Central Amazon. The observed buildup of CCl4 mixing ratios near the top of the main canopies provides new evidence for a potentially large biogenic source from the Basin. By demonstrating the need to represent tropical forests as biogenic sources of CCl4, our study may help narrow the gap between remote sensing observations of CCl4 and emission, chemistry, and transport models and therefore lead to improved predictions of its role in atmospheric chemistry and climate.

  16. Land-Cover Trends of the Central Basin and Range Ecoregion

    Science.gov (United States)

    Soulard, Christopher E.

    2006-01-01

    The U.S. Geological Survey (USGS) Land Cover Trends research project is focused on understanding the amounts, rates, trends, causes, and implications of contemporary land-use and land-cover (LU/LC) change in the United States. This project is supported by the USGS Geographic Analysis and Monitoring Program in collaboration with the U.S. Environmental Protection Agency (EPA) and the National Aeronautics and Space Administration (NASA). LU/LC change is a pervasive process that modifies landscape characteristics and affects a broad range of socioeconomic, biologic, and hydrologic systems. Understanding the impacts and feedbacks of LU/LC change on environmental systems requires an understanding of the rates, patterns, and driving forces of past, present, and future LU/LC change. The objectives of the Land Cover Trends project are to (1) determine and describe the amount, rates, and trends of contemporary LU/LC change by ecoregion for the period 1973-2000 for the conterminous United States, (2) document the causes, driving forces, and implications of change, and (3) synthesize individual ecoregion results into a national assessment of LU/LC change. The Land Cover Trends research team includes staff from the USGS National Center for Earth Resources Observation and Science (EROS), Rocky Mountain Geographic Science Center, Eastern Geographic Science Center, Mid-Continent Geographic Science Center, and the Western Geographic Science Center. Other partners include researchers at South Dakota State University, University of Southern Mississippi, and State University of New York College of Environmental Science and Forestry. This report presents an assessment of LU/LC change in the Central Basin and Range ecoregion for the period 1973-2000. The Central Basin and Range ecoregion is one of 84 Level-III ecoregions as defined by the Environmental Protection Agency. Ecoregions have served as a spatial framework for environmental resource management and to denote areas that contain

  17. Preliminary interpretation of industry two-dimensional seismic data from Susitna Basin, south-central Alaska

    Science.gov (United States)

    Lewis, Kristen A.; Potter, Christopher J.; Shah, Anjana K.; Stanley, Richard G.; Haeussler, Peter J.; Saltus, Richard W.

    2015-07-30

    Located approximately 80 kilometers northwest of Anchorage, Alaska, the Susitna Basin is a complex sedimentary basin whose tectonic history has been poorly understood. Recent interpretation of two-dimensional seismic reflection data integrated with well, aeromagnetic, and gravity data provides new insights into the structural and stratigraphic nature of the basin.

  18. Overpressure development and oil charging in the central Junggar Basin,Northwest China:Implication for petroleum exploration

    Institute of Scientific and Technical Information of China (English)

    CAI XiYuan

    2009-01-01

    The Junggar Basin is one of the largest and most petroliferous superimposed petroleum basins in China.The central depression area has become the frontier field for petroleum exploration.The characteristics of potential source rocks end reservoir sandstones,and the pressure regime in the central Junggar Basin were studied.Permian shales are dominated by hydrogen-rich,oil-prone algal organic matter,and Jurassic mudstones are dominated by hydrogen-poor,higher-plant derived organic matter.These source rocks are widespread and have been mature for hydrocarbon generation,suggesting good to excellent exploration potential,both for crude oils and for natural gases.The deeply buried Jurassic sandstones usually have low porosity and permeability.However,sandstones beneath the Jurassic/Cretaceous unconformity display relatively high porosity and permeability,suggesting that meteoric water leaching had improved the quality of the sandstones.Overpressure developed over much of the central Junggar Basin.The overpressured rocks are characterized by slightly increased interval transit time,low sandstone permeability,increased organic matter maturity,and high relative hydrocarbon-gas contents.Mudstones in the overpressured system have quite the same clay mineral compositions as mudstones in the lower part of the normally pressured system.Overpressure generation in the central Junggar Basin is best-to be explained as the result of hydrocarbon generation and fluid retention in low-permeability rocks.Petroleum generated from Permian and Jurassic source rocks could migrate laterally through preferential petroleum migration pathways and accumulated in structural traps or lithological traps in the overpressured system,or migrate vertically through faults/hydraulic fractures into the overlying,normally pressured system and accumulate in structural or lithological traps.Therefore,commercial petroleum reservoirs could be potentially found in both the overpressured system,and in the normally

  19. Overpressure development and oil charging in the central Junggar Basin,Northwest China:Implication for petroleum exploration

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The Junggar Basin is one of the largest and most petroliferous superimposed petroleum basins in China. The central depression area has become the frontier field for petroleum exploration. The characteristics of potential source rocks and reservoir sandstones, and the pressure regime in the central Junggar Basin were studied. Permian shales are dominated by hydrogen-rich, oil-prone algal organic matter, and Jurassic mudstones are dominated by hydrogen-poor, higher-plant derived organic matter. These source rocks are widespread and have been mature for hydrocarbon generation, suggesting good to excellent exploration potential, both for crude oils and for natural gases. The deeply buried Jurassic sandstones usually have low porosity and permeability. However, sandstones beneath the Jurassic/Cretaceous unconformity display relatively high porosity and permeability, suggesting that meteoric water leaching had improved the quality of the sandstones. Overpressure developed over much of the central Junggar Basin. The overpressured rocks are characterized by slightly increased interval transit time, low sandstone permeability, increased organic matter maturity, and high relative hydrocarbon-gas contents. Mudstones in the overpressured system have quite the same clay mineral compositions as mudstones in the lower part of the normally pressured system. Overpressure generation in the central Junggar Basin is best to be explained as the result of hydrocarbon generation and fluid retention in low-permeability rocks. Petroleum generated from Permian and Jurassic source rocks could migrate laterally through preferential petroleum migration pathways and accumulated in structural traps or lithological traps in the overpressured system, or migrate vertically through faults/ hydraulic fractures into the overlying, normally pressured system and accumulate in structural or lithological traps. Therefore, commercial petroleum reservoirs could be potentially found in both the overpressured

  20. Modeling Carbon Sequestration over the Large-Scale Amazon Basin, Aided by Satellite Observations. Part I: Wet- and Dry-Season Surface Radiation Budget Flux and Precipitation Variability Based on GOES Retrievals.

    Science.gov (United States)

    Gu, Jiujing; Smith, Eric A.; Cooper, Harry J.; Grose, Andrew; Liu, Guosheng; Merritt, James D.; Waterloo, Maarten J.; de Araújo, Alessandro C.; Nobre, Antonio D.; Manzi, Antonio O.; Marengo, Jose; de Oliveira, Paulo J.; von Randow, Celso; Norman, John; Silva Dias, Pedro

    2004-06-01

    detect rainfall processes, and yet they are responsive to the rapidly changing cloud fields, which are directly associated with precipitation life cycles over the Amazon basin. In conducting the validation analysis at high space time scales, the comparisons indicate systematic bias uncertainties on the order of 25%. These uncertainties are comparable to published values from an independent assessment of bias uncertainties inherent to the current highest-quality satellite retrievals, that is, from the Tropical Rainfall Measuring Mission. Because precipitation is a weak direct control on photosynthesis for the Amazon ecosystem, that is, photosynthesis is dominated by the strong diurnal controls of incoming PAR and ambient air-canopy temperatures, such uncertainties are tolerable. By the same token, precipitation is a strong control on soil thermal properties and carbon respiration through soil moisture, but the latter is a time-integrating variable and thus inhibits introduction of modeling errors caused by random errors in the precipitation forcing. The investigation concludes with analysis of the monthly, daily, and diurnal variations intrinsic to SRB and rainfall processes over the Amazon basin, including explanations of how these variations arise during wet- and dry-season periods.

  1. Field detection of eastern equine encephalitis virus in the Amazon Basin region of Peru using reverse transcription-polymerase chain reaction adapted for field identification of arthropod-borne pathogens.

    Science.gov (United States)

    O'Guinn, Monica L; Lee, John S; Kondig, John P; Fernandez, Roberto; Carbajal, Faustino

    2004-02-01

    In support of efforts to develop rapid diagnostic assays for use in the field, reverse transcription-polymerase chain reaction (RT-PCR) assays were developed to detect arboviruses circulating in the Amazon Basin region of Peru. Previous knowledge of arthropod/pathogen relationships allowed a focused evaluation to be conducted in November 2000 that assessed the feasibility and reliability of a mobile, rapid, field-expedient RT-PCR diagnostic system aimed at detecting eastern equine encephalitis virus (EEEV) in Culex (Melanoconion) pedroi mosquitoes. Modifications were made to a commercially available mobile molecular laboratory kit and assay procedures were tailored for use under harsh environmental conditions with field-collected and field-processed mosquitoes. From CO2 baited mosquito light traps, 3,227 Cx. (Mel.) pedroi mosquitoes were collected and sorted into 117 pools. The pools were processed and assayed in the field by RT-PCR and five of those pools were found positive for EEEV. Laboratory sequence analysis confirmed the presence of two distinct subtypes of EEEV.

  2. Digital resource modeling of the northern and central Appalachian Basin coal regions: Top producing coals

    Energy Technology Data Exchange (ETDEWEB)

    Ruppert, L.; Tewalt, S.; Bragg, L.; Wallack, R.; Jenkins, J.; Tully, J. [Geological Survey, Reston, VA (United States)

    1998-12-31

    The US Geological Survey is currently conducting a coal resource assessment of the coal beds and zones that are expected to provide the bulk of the Nation`s coal resources for the next few decades. In partnership with the state geologic surveys of Kentucky, Tennessee, West Virginia, Virginia, Pennsylvania, Ohio, and Maryland, six coal beds will be digitally assessed in the northern and central Appalachian Basin coal region. In ascending stratigraphic order, the beds which range from the Lower Pennsylvanian Pocahontas Formation to the Upper Pennsylvanian Monongahela Group are the Pocahontas No. 3, Pond Creek, Fire Clay, Lower Kittanning, Upper Freeport, and Pittsburgh coals. Comprehensive stratigraphic and geochemical databases have been developed for the coal beds. Maps that show the extent and mined areas of the beds, structure contour, isopach, and overburden thickness have been compiled for the Pittsburgh coal bed and are in preparation for the other coal beds. The resource model for the Pittsburgh coal bed indicates that of the original 33.6 billion short tons (30.5 billion tonnes) of Pittsburgh coal, approximately 15.9 billion short tons (14.4 billion tonnes) remain. The remaining coal is, however, higher in ash and sulfur, and generally thinner and under thicker overburden cover.

  3. Sedimentary characteristics of tide-dominated estuary in Donghetang Formation(Upper Devonian), central Tarim Basin

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The Donghetang Formation (Upper Devonian) in central Tarim Basin has been thought an important oil and gas reservoir since the abundant oil and gas resources were found in the wells W16, W20, W34, and other fields. However, the sedimentary environment of the Donghetang Formation has been disputed because it suffered from both tidal and fluvial actions and there were not rich fossils in the sandstone. After the authors analyzed sedimentary features by means of drill cores, well logging data, paleosols, and with SEM obseruations, three kinds of sedimentary environments were distinguished: alluvial fan, tide-dominated estuary, and shelf. Particularly, the sedimentary features of tide-dominated estuary were studied in detail. Besides, the authors discussed sedimentary characteristics of the Donghetang Formation which was divided into two fourth-order sequences and five system tracts. At the same time, according to the forming process of five system tracts, the whole vertical evolution and lateral transition of tide-dominated estuary were illustrated clearly. Finally, the reservoir quality was evaluated based on porosity and permeability.

  4. Evolution of the Moxizhuang Oil Field, Central Junggar Basin, Northwest China

    Institute of Scientific and Technical Information of China (English)

    Zou Huayao; Zhang Yuanchun; Liu Jianzhang; Shi Jiannan

    2008-01-01

    Current oil saturation in the Moxizhuang (莫西庄) Oil Field in central Janggar (准噶尔) basin was evaluated by logging interpretation and measured on core samples, and the paleo-oil saturation in both the pay zones and water zones was investigated by graln-containing-oil inclusion (GOI) analysis.The pay zones in this field have low oil saturation and display low resistivity and small contrast between pay zones and water zones, and are classified as low-porosity, low oil saturation, and low resistivity reservoirs. Both the current low oil-saturation pay zones and the water zones above 4 365 m have high GOI values (up to 38%), suggesting high paleo-oil saturation. The significant difference between current oil saturation from both logging interpretation and core sample measurement and paleo-oil saturation indicated by GOI analysis suggests that this low oil-saturation field evolved from a high oil-saturation pool. Lateral re-migration and spill of formally trapped oil owing to changes in structural configuration since Neogene was the most plausible mechanism for oil loss in the Moxizhuang Oil Field.The combined effects of differential accumulation in the charge phase and the differential re-migration and spill of accumulated oil in Neogene are responsible for the complicated correlation between residual oil saturation and porosity/permeability of the reservoir sandstones and the distribution of low oil-saturation pay zones and paleo-oil zones (current water zones).

  5. Geophysical Evidence about of Continental Margin Central in the Basin of Cuba

    Directory of Open Access Journals (Sweden)

    María Caridad Rifá Hernández

    2013-06-01

    Full Text Available The Central basin of Cuba, bounded by the Zaza Tuinicú and La Trocha faults, is the site of threesmall oil fields and many showings, both at the surface and in wells. The petroleum is found mainlyin volcano-sedimentary rocks and sediments laid down during the Cuban progeny. With contrastswith petroleum on the north coast of the country in the intensely folded sediments of the continentalmargin in the Provinces of Havana, Mayabeque and Matanzas. The presence of these sedimentsbeneath the Cretaceous volcanic arc has been proposed based on geological evidence. Nevertheless,these sediments have yet to be encountered in the numerous drill holes present in the area. Thisstudy offers geophysical evidence pointing to the presence of the Placetas and Camajuaní tectonicstratigraphicunits at no great depths. The present analysis given here takes into account a geologicalinterpretation as well as both regional and local gravitational, magnetic and seismic studies; well datais also included as an integral part of the study. Finally, after presenting evidence based on seismicexploration and taking into account the limitations of this method applied to the Cuban fold belt, wepropose the use of more modern techniques to locate raised portions of the Placetas and Camajuanítectono-stratigraphic units.

  6. Rainfall and land use empirically coupled to forecast landslides in the Esino river basin, central Italy

    Science.gov (United States)

    Gioia, E.; Carone, T.; Marincioni, F.

    2015-06-01

    A coupled empirical approach to highlight relationships between rainfall, vegetation segmentation, and landslide occurrence is discussed. To reveal such links, two important rainfall events, which occurred over the Esino river basin in central Italy in November 2013 and May 2014, were analysed. The correlation between rainfall and landslides was evaluated by applying an intensity-duration (ID) threshold method, whereas the correlation between vegetation segmentation and landslides was investigated using morphological spatial pattern analysis (MSPA). This coupled approach represents an attempt to find both timing and location of landslide occurrence through an empirical (black box) analysis. Results showed: (i) the ID minimum threshold proposed in a previous study (Gioia et al., 2015) to be verified as an effective equation to assess the rainfall conditions likely to trigger landslides in the study area ("when"), and (ii) the core areas and the fragmented vegetation structures defined by the MSPA to be the most affected by slope failures ("where"). These encouraging findings prompt additional testing and the application of such a coupled empirical approach so that it is possible to achieve an integrated basis for landslide forecasting.

  7. Parascolymia (Scleractinia: Lobophylliidae) in the Central Paratethys Sea (Vienna Basin, Austria) and its possible biogeographic implications.

    Science.gov (United States)

    Reuter, Markus; Wiedl, Thomas; Piller, Werner E

    2015-01-01

    Palaeobiogeographical and palaeodiversity patterns of scleractinian reef corals are generally biased due to uncertain taxonomy and a loss of taxonomic characters through dissolution and recrystallization of the skeletal aragonite in shallow marine limestones. Herein, we describe a fossil lobophylliid coral in mouldic preservation from the early middle Miocene Leitha Limestone of the Central Paratethys Sea (Vienna Basin, Austria). By using grey-scale image inversion and silicone rubber casts for the visualization of the original skeletal anatomy and the detection of distinct micromorphological characters (i.e. shape of septal teeth, granulation of septocostae) Parascolymia bracherti has been identified as a new species in spite of the dissolved skeleton. In the recent era, Parascolymia like all Lobophylliidae is restricted to the Indo-Pacific region, where it is represented by a single species. The new species proves the genus also in the Miocene Mediterranean reef coral province. A review of the spatio-temporal relationships of fossil corals related to Parascolymia indicates that the genus was probably rooted in the Eastern Atlantic‒Western Tethys region during the Paleocene to Eocene and reached the Indo-Pacific region not before the Oligocene. The revealed palaeobiogeographical pattern shows an obvious congruence with that of Acropora and tridacnine bivalves reflecting a gradual equatorwards retreat of the marine biodiversity center parallel to the Cenozoic climate deterioration. PMID:26201071

  8. Hydrogeochemical investigations in a drained lake area: the case of Xynias basin (Central Greece).

    Science.gov (United States)

    Charizopoulos, Nikos; Zagana, Eleni; Stamatis, Georgios

    2016-08-01

    In Xynias drained Lake Basin's area, central Greece, a hydrogeochemical research took place including groundwater sampling from 30 sampling sites, chemical analysis, and statistical analysis. Groundwaters present Ca-Mg-HCO3 as the dominant hydrochemical type, while their majority is mixed waters with non-dominant ion. They are classified as moderately hard to hard and are characterized by oxidizing conditions. They are undersaturated with respect to gypsum, anhydrite, fluorite, siderite, and magnesite and oversaturated in respect to calcite, aragonite, and dolomite. Nitrate concentration ranges from 4.4 to 107.4 mg/L, meanwhile 13.3 % of the samples exceed the European Community (E.C.) drinking water permissible limit. The trace elements Fe, Ni, Cr, and Cd present values of 30, 80, 57, and 50 %, respectively, above the maximum permissible limit set by E.C. Accordingly, the majority of the groundwaters are considered unsuitable for drinking water needs. Sodium adsorption ratio values (0.04-3.98) and the electrical conductivity (227-1200 μS/cm) classify groundwaters as suitable for irrigation uses, presenting low risk and medium soil alkalization risk. Factor analysis shows that geogenic processes associated with the former lacustrine environment and anthropogenic influences with the use of fertilizers are the major factors that characterized the chemical composition of the groundwaters. PMID:27450374

  9. Spatio-Temporal Variations and Source Apportionment of Water Pollution in Danjiangkou Reservoir Basin, Central China

    Directory of Open Access Journals (Sweden)

    Pan Chen

    2015-05-01

    Full Text Available Understanding the spatio-temporal variation and the potential source of water pollution could greatly improve our knowledge of human impacts on the environment. In this work, data of 11 water quality indices were collected during 2012–2014 at 10 monitoring sites in the mainstream and major tributaries of the Danjiangkou Reservoir Basin, Central China. The fuzzy comprehensive assessment (FCA, the cluster analysis (CA and the discriminant analysis (DA were used to assess the water pollution status and analyze its spatio-temporal variation. Ten sites were classified by the high pollution (HP region and the low pollution (LP region, while 12 months were divided into the wet season and the dry season. It was found that the HP region was mainly in the small tributaries with small drainage areas and low average annual discharges, and it was also found that most of these rivers went through urban areas with industrial and domestic sewages input into the water body. Principal component analysis/factor analysis (PCA/FA was applied to reveal potential pollution sources, whereas absolute principal component score-multiple linear regression (APCS-MLR was used to identify their contributions to each water quality variable. The study area was found as being generally affected by industrial and domestic sewage. Furthermore, the HP region was polluted by chemical industries, and the LP region was influenced by agricultural and livestock sewage.

  10. Cenozoic stratigraphic development in the north Chilean forearc: Implications for basin development and uplift history of the Central Andean margin

    Science.gov (United States)

    Hartley, Adrian J.; Evenstar, Laura

    2010-11-01

    Analysis of the Cenozoic stratigraphic development of the forearc of northern Chile between 18°S and 23°30'S, allows constraints to be placed on the timing and nature of basin formation and the uplift history of the Central Andes. Chronostratigraphic charts have been constructed from 20 lithostratigraphic sections distributed throughout the forearc. Sections were taken from the Longitudinal Valley, Central Depression, Calama Basin, Salar de Atacama, Precordillera and the western flank of the Western Cordillera. Correlation and timing of events is largely based on the presence of dated volcanic horizons in all the studied sections. Three chronostratigraphic units are defined based upon the presence of regional unconformities. Deposition of the Late Eocene to Early Miocene chronostratigraphic unit (38-19 Ma) commenced across an irregular unconformity surface between ˜ 38 and 30 Ma with alluvial fan and fluvial sediments derived from the east interbedded with rhyolitic ignimbrites. Aggradation after 25 Ma resulted in development of a large broad basin over much of northern Chile that expanded eastwards through onlap onto basement. Deposition terminated around 19 Ma with the development of an angular unconformity over much, but not all of the study area. During deposition of the Early to Late Miocene chronostratigraphic unit (18-10 Ma) emergent volcanic source areas to the east provided catchments for large fluvial systems that drained westwards into endorheic ephemeral lacustrine basins. Fold growth affected sedimentation restricting accommodation space to small intra-thrust basins in the Precordillera and localised disruption and unconformity development in the Longitudinal Valley. The Late Miocene to present day chronostratigraphic unit (10-0 Ma) followed the development of a regional angular unconformity at 10 Ma. Sedimentation was restricted to a series of thrust-bounded endorheic basins in both the Central Depression and the Precordillera sourced from the east

  11. Source to sink: Evolution of lignin composition in the Madre de Dios River system with connection to the Amazon basin and offshore

    Science.gov (United States)

    Feng, Xiaojuan; Feakins, Sarah J.; Liu, Zongguang; Ponton, Camilo; Wang, Renée. Z.; Karkabi, Elias; Galy, Valier; Berelson, William M.; Nottingham, Andrew T.; Meir, Patrick; West, A. Joshua

    2016-05-01

    While lignin geochemistry has been extensively investigated in the Amazon River, little is known about lignin distribution and dynamics within deep, stratified river channels or its transformations within soils prior to delivery to rivers. We characterized lignin phenols in soils, river particulate organic matter (POM), and dissolved organic matter (DOM) across a 4 km elevation gradient in the Madre de Dios River system, Peru, as well as in marine sediments to investigate the source-to-sink evolution of lignin. In soils, we found more oxidized lignin in organic horizons relative to mineral horizons. The oxidized lignin signature was maintained during transfer into rivers, and lignin was a relatively constant fraction of bulk organic carbon in soils and riverine POM. Lignin in DOM became increasingly oxidized downstream, indicating active transformation of dissolved lignin during transport, especially in the dry season. In contrast, POM accumulated undegraded lignin downstream during the wet season, suggesting that terrestrial input exceeded in-river degradation. We discovered high concentrations of relatively undegraded lignin in POM at depth in the lower Madre de Dios River in both seasons, revealing a woody undercurrent for its transfer within these deep rivers. Our study of lignin evolution in the soil-river-ocean continuum highlights important seasonal and depth variations of river carbon components and their connection to soil carbon pools, providing new insights into fluvial carbon dynamics associated with the transfer of lignin biomarkers from source to sink.

  12. An integrated framework to assess adaptation options to climate change impacts in an irrigated basin in Central North Chile

    Science.gov (United States)

    Vicuna, S.; Melo, O.; Meza, F. J.; Alvarez, P.; Maureira, F.; Sanchez, A.; Tapia, A.; Cortes, M.; Dale, L. L.

    2013-12-01

    Future climate conditions could potentially affect water supply and demand on water basins throughout the world but especially on snowmelt-driven agriculture oriented basins that can be found throughout central Chile. Increasing temperature and reducing precipitation will affect both the magnitude and timing of water supply this part of the world. Different adaptation strategies could be implemented to reduce the impacts of such scenarios. Some could be incorporated as planned policies decided at the basin or Water Use Organization levels. Examples include changing large scale irrigation infrastructure (reservoirs and main channels) either physically or its operation. Complementing these strategies it is reasonable to think that at a disaggregated level, farmers would also react (adapt) to these new conditions using a mix of options to either modify their patterns of consumption (irrigation efficiency, crop mix, crop area reduction), increase their ability to access new sources of water (groundwater, water markets) or finally compensate their expected losses (insurance). We present a modeling framework developed to represent these issues using as a case study the Limarí basin located in Central Chile. This basin is a renowned example of how the development of reservoirs and irrigation infrastructure can reduce climate vulnerabilities allowing the economic development of a basin. Farmers in this basin tackle climate variability by adopting different strategies that depend first on the reservoir water volume allocation rule, on the type and size of investment they have at their farms and finally their potential access to water markets and other water supplies options. The framework developed can be used to study these strategies under current and future climate scenarios. The cornerstone of the framework is an hydrology and water resources model developed on the WEAP platform. This model is able to reproduce the large scale hydrologic features of the basin such as

  13. Suspected Lead Poisoning in an Amazon Parrot

    OpenAIRE

    McDonald, Lawrence J.

    1986-01-01

    A double yellow headed Amazon parrot (Amazona ochrocephala tresmariae) of unknown age and sex was examined for an acute onset of anorexia, listlessness, central nervous system signs and diarrhea. A tentative diagnosis of lead toxicosis was achieved based on radiographs, clinical pathology and response to therapy. Chelation therapy (Calcium EDTA) and supportive measures resulted in an uneventful recovery.

  14. Petrogenesis of the crater-facies Tokapal kimberlite pipe, Indrāvati Basin, Central India

    Institute of Scientific and Technical Information of China (English)

    N.V. Chalapathi Rao; B. Lehmann; B.K. Panwar; Alok Kumar; D. Mainkar

    2014-01-01

    New geochemical data of the crater-facies Tokapal kimberlite system sandwiched between the lower and upper stratigraphic horizons of the Mesoproterozoic Indrāvati Basin are presented. The kimberlite has been subjected to extensive and pervasive low-temperature alteration. Spinel is the only primary phase identifiable, while olivine macrocrysts and juvenile lapilli are largely pseudomorphed (talc-serpentine-carbonate alteration). However, with the exception of the alkalies, major element oxides display systematic fractionation trends; likewise, HFSE patterns are well correlated and allow petrogenetic interpretation. Various crustal contamination indices such as (SiO2 þ Al2O3 þ Na2O)/(MgO þ K2O) and Si/Mg are close to those of uncontaminated kimberlites. Similar La/Yb (79e109) of the Tokapal samples with those from the kimberlites of Wajrakarur (73e145) and Narayanpet (72e156), Eastern Dharwar craton, southern India implies a similarity in their genesis. In the discriminant plots involving HFSE the Tokapal samples display strong affinities to Group II kimberlites from southern Africa and central India as well as to‘transitional kimberlites’ from the Eastern Dharwar craton, southern India, and those from the Prieska and Kuruman provinces of southern Africa. There is a striking similarity in the depleted-mantle (TDM) Nd model ages of the Tokapal kimberlite system, Bastar craton, the kimberlites from NKF and WKF, Eastern Dharwar craton, and the Majhgawan diatreme, Bundelkhand craton, with the emplacement age of some of the lamproites from within and around the Palaeo-Mesoproterozoic Cuddapah basin, southern India. These similar ages imply a major tectonomagmatic event, possibly related to the break-up of the supercontinent of Columbia, at 1.3e1.5 Ga across the three cratons. The ‘transitional’ geochemical features displayed by many of the Mesoproterozoic potassic-ultrapotassic rocks, across these Indian cratons are inferred to be memories of the

  15. Tectono-sedimentary evolution of the Tertiary Piedmont Basin (NW Italy) within the Oligo-Miocene central Mediterranean geodynamics

    Science.gov (United States)

    Maino, Matteo; Decarlis, Alessandro; Felletti, Fabrizio; Seno, Silvio

    2013-06-01

    analyze the tectono-sedimentary and thermochronometric constraints of the Tertiary Piedmont Basin (TPB) and its adjoining orogen, the Ligurian Alps, providing new insights on the basin evolution in response to a changing geodynamic setting. The geometry of the post-metamorphic faults of the Ligurian belt as well as the fault network that controlled the Oligo-Miocene TPB deposition has been characterized through a detailed structural analysis. Three main faulting stages have been distinguished and dated thanks to the relationships among faults and basin stratigraphy and thermochronometric data. The first stage (F1, Rupelian-Early Chattian) is related to the development of extensional NNW-directed faults, which controlled the exhumation of the orogen and the deposition of nearshore clastics. During the Late Chattian, the basin drowning is marked by mudstones and turbidites, which deposition was influenced by the second faulting stage (F2). This phase was mainly characterized by NE- to ENE-striking faults developed within a transtensional zone. Since the Miocene, the whole area was dominated by transpressive tectonics. The sedimentation was represented by a condensed succession followed by a very thick, turbiditic complex. At the regional scale, this succession of events reflects the major geodynamic reorganization in the central Mediterranean region during the Oligo-Miocene times, induced by the late-collisional processes of the Alps, by the eastward migration of the Apennines subduction and by the opening of extensional basins (i. e., the Liguro-Provençal Ocean).

  16. Sedimentology and hydrocarbon habitat of the submarine-fan deposits of the Central Carpathian Paleogene Basin (NE Slovakia)

    Energy Technology Data Exchange (ETDEWEB)

    Sotak, J. [Slovak Academy of Sciences, Banska Bystrica (Slovakia). Geological Institute; Pereszlenyi, M. [VVNP Research Oil Company for Exploration and Production, Bratislava (Slovakia); Marschalko, R.; Starek, D. [Slovak Academy of Sciences, Bratislava (Slovakia). Geological Institute; Milicka, J. [Comenius University, Bratislava (Slovakia). Dept. of Geochemistry

    2001-01-01

    The Central Carpathian Paleogene Basin accommodates a subsiding area of the destructive plate-margin. The basin history comprises marginal faulting and alluvial fan accumulation (E{sub 2}); transgressive onlap by shoreface sediments and carbonate platform deposits (E{sub 2}); glacio-eustatic regression induced by cooling (Terminal Eocene Event); forced regression, tectonic subsidence and growth-fault accumulation of basin-floor and slope fans (E{sub 3}); decelerating subsidence, aggradation and sea-level rising during the mud-rich deposition (O{sub 1}); high-magnitude drop in sea-level (Mid-Oligocene Event), retroarc backstep of depocenters and lowstand accumulation of sand-rich fans and suprafans (O{sub 2}-M{sub 1}); subduction-related shortening and basin inversion along the northern margins affected by backthrusting and transpressional deformation (O{sub 2}-M{sub 1}). The basin-fill sequence has poor (TOC {<=} 0.5%) to fair (TOC < 1.0%) quality of source rocks. Maturity of OM ranges from initial to relic stage of HC generation. Paleogene rock-extracts display a good correlation with scarce trapped oils. 'The presence of solid bitumens and HC-rich fluid inclusions indicates overpressure conditions during HC generation and migration. Potential HC reservoirs can be expected in porous lithologies (scarp breccias), in basement highs and traps related to backthrusting, fault-propagation folding and strike-slip tectonics. (author)

  17. Digital model of the seabed geomorphology of southern-central Espirito Santo basin and northern Campos basin; Modelo digital da geomorfologia do fundo oceanico do centro-sul da bacia do Espirito Santo e norte da bacia de Campos

    Energy Technology Data Exchange (ETDEWEB)

    Schreiner, Simone; Souza, Mariana Beatriz Ferraz Mendonca de; Migliorelli, Joana Paiva Robalo [Petroleo Brasileiro S. A. (PETROBRAS), Rio de Janeiro, RJ (Brazil). Unidade de Servicos de Exploracao e Producao], Emails: schreiner@petrobras.com.br, mbfms.fototerra@petrobras.com.br, joanamigli.fototerra@petrobras.com.br

    2009-05-15

    That communication brings the result of a bathymetric mosaic of converted in a digital model of the ocean topography, consisting of 17 seismic projects 3D, besides 17 multibeam bathymetry surveys of South-Central Espirito Santo Basin and Northern Campos Basin.

  18. Fate of copper complexes in hydrothermally altered deep-sea sediments from the Central Indian Ocean Basin.

    Digital Repository Service at National Institute of Oceanography (India)

    Chakraborty, P.; Sander, S.G.; Jayachandran, S.; Nath, B.N.; Nagaraju, G.; Chennuri, K.; Vudamala, K.; Lathika, N.; Mascarenhas-Pereira, M.B.L.

    -sediment interaction, deep-sea sediment, Cu, hydrothermal alteration, sequential extraction, kinetic extraction method. CAPSULE: Hydrothermally influenced deep-sea sediments from Central Indian Ocean Basin may significantly contribute to the global Cu flux during.... 2.3 Sequential Extraction methods: Modified forms of the sequential extraction protocols by BCR (Quevauviller et al.,1993) and Poulton and Canfield (2007) were used to study Cu speciation and its distribution in different binding phases...

  19. A coupled empirical approach for rainfall and land use correlation to landslide occurrence in the Esino river basin, central Italy

    OpenAIRE

    E. Gioia; T. Carone; F. Marincioni

    2015-01-01

    A coupled empirical approach for studying possible correlations among rainfall, vegetation segmentation and landslide occurrence is discussed. To reveal such links two important rainfall events, occurred over the Esino river basin in central Italy, in November 2013 and May 2014, were analysed. The correlation between rainfall and landslides was carried out applying an intensity–duration (ID) threshold method, whereas the correlation between vegetation segmen...

  20. Geology, thermal maturation, and source rock geochemistry in a volcanic covered basin: San Juan sag, south-central Colorado

    Science.gov (United States)

    Gries, R.R.; Clayton, J.L.; Leonard, C.

    1997-01-01

    The San Juan sag, concealed by the vast San Juan volcanic field of south-central Colorado, has only recently benefited from oil and gas wildcat drilling and evaluations. Sound geochemical analyses and maturation modeling are essential elements for successful exploration and development. Oil has been produced in minor quantities from an Oligocene sill in the Mancos Shale within the sag, and major oil and gas production occurs from stratigraphically equivalent rocks in the San Juan basin to the south-west and in the Denver basin to the northeast. The objectives of this study were to identify potential source rocks, assess thermal maturity, and determine hydrocarbon-source bed relationships. Source rocks are present in the San Juan sag in the upper and lower Mancos Shale (including the Niobrara Member), which consists of about 666 m (2184 ft) of marine shale with from 0.5 to 3.1 wt. % organic carbon. Pyrolysis yields (S1 + S2 = 2000-6000 ppm) and solvent extraction yields (1000-4000 ppm) indicate that some intervals within the Mancos Shale are good potential source rocks for oil, containing type II organic matter, according to Rock-Eval pyrolysis assay. Oils produced from the San Juan sag and adjacent part of the San Juan basin are geochemically similar to rock extracts obtained from these potential source rock intervals. Based on reconstruction of the geologic history of the basin integrated with models of organic maturation, we conclude that most of the source rock maturation occurred in the Oligocene and Miocene. Little to no maturation took place during Laramide subsidence of the basin, when the Animas and Blanco Basin formations were deposited. The timing of maturation is unlike that of most Laramide basins in the Rocky Mountain region, where maturation occurred as a result of Paleocene and Eocene basin fill. The present geothermal gradient in the San Juan sag is slightly higher (average 3.5??C/100 m; 1.9??F/100 ft) than the regional average for southern Rocky

  1. Mercury and flooding cycles in the Tapajos river basin, Brazilian Amazon: The role of periphyton of a floating macrophyte (Paspalum repens)

    International Nuclear Information System (INIS)

    Methylmercury (MeHg) increases mercury (Hg) toxicity and is biomagnified in the trophic chain contaminating riverine Amazon populations. Freshwater macrophyte roots are a main site of Hg methylation in different Brazilian environments. Paspalum repens periphyton was sampled in four floodplain lakes during the dry, rainy and wet seasons for measurement of total Hg (THg), MeHg, Hg methylation potentials, %C, %N, δ13C, δ15N and bacterial heterotrophic production as 3H-leucine incorporation rate. THg concentration varied from 67 to 198 ng/g and the potential of Me203Hg formation was expressive (1-23%) showing that periphyton is an important matrix both in the accumulation of Hg and in MeHg production. The concentration of MeHg varied from 1 to 6 ng/g DW and was positively correlated with Me203Hg formation. Though methylmercury formation is mainly a bacterial process, no significant correlation was observed between the methylation potentials and bacterial production. The multiple regressions analyses suggested a negative correlation between THg and %C and %N and between methylation potential and δ13C. The discriminant analysis showed a significant difference in periphyton δ15N, δ13C and THg between seasons, where the rainy season presented higher δ15N and the wet period lighter δ13C, lower THg values and higher Me203Hg formation. This exploratory study indicates that the flooding cycle could influence the periphyton composition, mercury accumulation and methylmercury production. - Research highlights: → During rainy season mercury (Hg2+) is carried out from terrestrial to aquatic systems by runoff. → Macrophyte roots accumulates Hg2+ from suspended particulate matter (SPM). → Hg methylation increases during the wet season. → Flooded forest is a source of labile organic carbon and bioavailable Hg. → Macrophytes decompose during the dry season and made up terrestrial soil.

  2. Implications for Fault and Basin Geometry in the Central California Coast Ranges from Preliminary Gravity and Magnetic Data

    Science.gov (United States)

    Langenheim, V. E.; Jachens, R. C.; Graymer, R. W.; Wentworth, C. M.

    2008-12-01

    Preliminary aeromagnetic and newly processed gravity data help define block-bounding faults and deep sedimentary basins in the central California Coast Ranges, ranging from the Hosgri fault east to the San Andreas fault and from Monterey Bay south to Pt. Conception. Interpretation of these data results in an improved framework for seismic hazard and groundwater studies. Aeromagnetic data include a new survey with a flight-line spacing of 800 m at a nominal 300 m above ground and covering 15,000 km2. More than 11,500 gravity measurements, reprocessed with terrain corrections calculated from 30-m DEMs, form a roughly 2-km grid over most of the study area. Combined potential-field data and existing geologic mapping, delineate major fault-bounded blocks in the central California Coast Ranges. Main block-bounding faults from west to east include the San Gregorio- Hosgri, San Luis-Willmar-Santa Maria River-Little Pine, Oceanic-West Huasna, Nacimiento, Rinconada-South Cuyama, San Juan-Chimineas-Morales, and San Andreas faults. Most of these faults have evidence of Quaternary activity. Gravity gradients indicate that the reach of the San Andreas fault bounding the Gabilan Range and the northern extension of the Rinconada fault bounding the Santa Lucia Range dip steeply southwestward and have a reverse component of slip. Magnetic and microseismicity data suggest that the northern reach of the Hosgri fault dips eastward. The potential-field data also delineate several deep sedimentary basins, such as the 3-4 km deep Cuyama basin, the Santa Maria basin, and several basins along and possibly offset by the Rinconada fault. Gravity data show that the main west-northwest-striking faults bounding the Cuyama basin dip away from the basin, indicating compression adjacent to the big bend in the San Andreas fault. Prominent gravity and magnetic highs northeast of the San Andreas fault immediately east of Cuyama Valley suggest that there the San Andreas fault dips southwest. Such dip

  3. Statistical prediction of seasonal discharge in the Naryn basin for water resources planning in Central Asia

    Science.gov (United States)

    Apel, Heiko; Gafurov, Abror; Gerlitz, Lars; Unger-Shayesteh, Katy; Vorogushyn, Sergiy; Merkushkin, Aleksandr; Merz, Bruno

    2016-04-01

    The semi-arid regions of Central Asia crucially depend on the water resources supplied by the mountainous areas of the Tien-Shan and Pamirs. During the summer months the snow and glacier melt water of the rivers originating in the mountains provides the only water resource available for agricultural production but also for water collection in reservoirs for energy production in winter months. Thus a reliable seasonal forecast of the water resources is crucial for a sustainable management and planning of water resources.. In fact, seasonal forecasts are mandatory tasks of national hydro-meteorological services in the region. Thus this study aims at a statistical forecast of the seasonal water availability, whereas the focus is put on the usage of freely available data in order to facilitate an operational use without data access limitations. The study takes the Naryn basin as a test case, at which outlet the Toktogul reservoir stores the discharge of the Naryn River. As most of the water originates form snow and glacier melt, a statistical forecast model should use data sets that can serve as proxy data for the snow masses and snow water equivalent in late spring, which essentially determines the bulk of the seasonal discharge. CRU climate data describing the precipitation and temperature in the basin during winter and spring was used as base information, which was complemented by MODIS snow cover data processed through ModSnow tool, discharge during the spring and also GRACE gravimetry anomalies. For the construction of linear forecast models monthly as well as multi-monthly means over the period January to April were used to predict the seasonal mean discharge of May-September at the station Uchterek. An automatic model selection was performed in multiple steps, whereas the best models were selected according to several performance measures and their robustness in a leave-one-out cross validation. It could be shown that the seasonal discharge can be predicted with

  4. Long-term agroecosystem research in the central Mississippi river basin: introduction, establishment, and overview.

    Science.gov (United States)

    Sadler, E John; Lerch, Robert N; Kitchen, Newell R; Anderson, Stephen H; Baffaut, Claire; Sudduth, Kenneth A; Prato, Anthony A; Kremer, Robert J; Vories, Earl D; Myers, D Brent; Broz, Robert; Miles, Randall J; Young, Fred J

    2015-01-01

    Many challenges currently facing agriculture require long-term data on landscape-scale hydrologic responses to weather, such as from the Goodwater Creek Experimental Watershed (GCEW), located in northeastern Missouri, USA. This watershed is prone to surface runoff despite shallow slopes, as a result of a significant smectitic clay layer 30 to 50 cm deep that restricts downward flow of water and gives rise to a periodic perched water table. This paper is the first in a series that documents the database developed from GCEW. The objectives of this paper are to (i) establish the context of long-term data and the federal infrastructure that provides it, (ii) describe the GCEW/ Central Mississippi River Basin (CMRB) establishment and the geophysical and anthropogenic context, (iii) summarize in brief the collected research results published using data from within GCEW, (iv) describe the series of papers this work introduces, and (v) identify knowledge gaps and research needs. The rationale for the collection derives from converging trends in data from long-term research, integration of multiple disciplines, and increasing public awareness of increasingly larger problems. The outcome of those trends includes being selected as the CMRB site in the USDA-ARS Long-Term Agro-Ecosystem Research (LTAR) network. Research needs include quantifying watershed scale fluxes of N, P, K, sediment, and energy, accounting for fluxes involving forest, livestock, and anthropogenic sources, scaling from near-term point-scale results to increasingly long and broad scales, and considering whole-system interactions. This special section informs the scientific community about this database and provides support for its future use in research to solve natural resource problems important to US agricultural, environmental, and science policy.

  5. Relationship between chemical composition and magnetic susceptibility in sediment cores from Central Indian Ocean Basin

    Indian Academy of Sciences (India)

    J N Pattan; G Parthiban; V K Banakar; A Tomer; M Kulkarni

    2008-04-01

    Three sediment cores in a north–south transect (3°N to 13°S) from different sediment types of the Central Indian Ocean Basin (CIOB) are studied to understand the possible relationship between magnetic susceptibility () and Al, Fe, Ti and Mn concentrations. The calcareous ooze core exhibit lowest (12.32 × 10-7m3 kg−1), Al (2.84%), Fe (1.63%) and Ti (0.14%), terrigenous clay core with moderate (29.9 × 10-7 m3 kg−1) but highest Al (6.84%), Fe (5.20%) and Ti (0.44%), and siliceous ooze core with highest (38.06 × 10-7 m3 kg−1) but moderate Al (4.49%), Fe (2.80%) and Ti (0.19%) contents. The distribution of and detrital proxy elements (Al, Fe, and Ti) are identical in both calcareous and siliceous ooze. Interestingly, in terrigenous core, the behaviour of is identical to only Ti content but not with Al and Fe suggesting possibility of Al and Fe having a non-detrital source. The occurrence of phillipsite in terrigenous clay is evident by the Al-K scatter plot where trend line intersects K axis at more than 50% of total K suggesting excess K in the form of phillipsite. Therefore, the presence of phillipsite might be responsible for negative correlation between and Al ( = −0.52). In siliceous ooze the strong positive correlations among , Alexc and Feexc suggest the presence of authigenic Fe-rich smectite. High Mn content (0.5%) probably in the form of manganese micronodules is also contributing to in both calcareous and siliceous ooze but not in the terrigenous core where mean Mn content (0.1%) is similar to crustal abundance. Thus, systematically records the terrigenous variation in both the biogenic sediments but in terrigenous clay it indirectly suggests the presence of authigenic minerals.

  6. A LEPS approach to the predictability of intense rain storms in the Central Mediterranean basin

    Directory of Open Access Journals (Sweden)

    S. Federico

    2008-04-01

    Full Text Available This study investigates a method for best member selection of a Limited area model Ensemble Prediction System (LEPS with the goal to increase quantitative precipitation forecast. A case study that occurred between 22-24 May 2002 over Calabria, southern Italy, is discussed.

    Mediterranean storms often develop under upper level disturbances which are usually associated with high values of potential vorticity. Anomalously high values of potential vorticity can be identified by the METEOSAT water vapor channel centered around 6.3 μm because they are associated with dark band on the METEOSAT image. This signature offers a chance to identify the upper level disturbance that can be exploited in data void countries as Calabria.

    The working hypothesis is that the uncertainty in the representation of the upper-level disturbance has a major impact on the precipitation forecast. This issue is utilized in an ensemble forecast where member forecasts are compatible with the analysis and forecast errors. These members are grouped in five clusters by a hierarchical clustering technique which utilizes the height of the dynamical tropopause to compute distances between members. Therefore the members of a cluster have a similar representation of the upper level disturbance. For each cluster a representative member is selected and its pseudo water vapor image is compared with the corresponding METEOSAT 7 water vapor image at a specific time, antecedent to the rain occurrence over Calabria. The subjective evaluation of the comparison allows to gain physical insight in the storm evolution and to select representative members which are more in agreement with the METEOSAT image.

    Results, even if for a case study, show the feasibility of the methodology that, if confirmed by further investigations, could be valuable in data void countries as the central Mediterranean basin.

  7. Herpetofauna of the cedar glades and associated habitats of the Inner Central Basin of middle Tennessee

    Science.gov (United States)

    Niemiller, M.L.; Graham, Reynolds R.; Glorioso, B.M.; Spiess, J.; Miller, B.T.

    2011-01-01

    The cedar glades and barrens of the Inner Central Basin (ICB) of middle Tennessee support a unique and diverse flora and fauna and represent some of the state's most valued natural areas. We conducted herpetofaunal inventories of the cedar glades, associated barrens, cedar-hardwood forest, and adjacent aquatic habitats of the Stones River drainage of Middle Tennessee, focusing our sampling effort primarily at seven state- or federally owned properties in Rutherford and Wilson counties. These properties included Stones River National Battlefield (SRNB), Flat Rock State Natural Area (FRSNA), Vesta Cedar Glade State Natural Area (VSNA), Fall Creek Recreation Area (FCRA) on J. Percy Priest Wildlife Management Area, Cedars of Lebanon State Forest (CLSF), Cedars of Lebanon State Forest Natural Area (CLSNA), and Cedars of Lebanon State Park (CLSP). We used a variety of inventory techniques in terrestrial, aquatic, and subterranean habitats to survey these properties periodically from 1989 to 2010. We documented 49 species (22 amphibian and 27 reptile) accounting for 75.4% of the 65 herpetofaunal species thought to occur in the ICB, including records for Cemophora coccinea, Aneides aeneus, Gyrinophilus palleucus, Ambystoma barbouri, and Pseudotriton montanus. We found differences in alpha and beta diversity between sites, with the CLSF complex containing a high of 41 herpetofaunal species and FRSNA containing a low of 23 species. Beta diversity comparisons indicated similarity in amphibian species composition between FRSNA and CLSF and between SRNB and CLSF (9 shared species), and in reptile species composition between VSNA and the CLSF complex (16 shared species). We compare the results of our inventory with two previous studies conducted in the area and discuss the relative abundance, conservation, and threats to the herpetofaunal community of these habitats.

  8. Geothermal energy from deep sedimentary basins: The Valley of Mexico (Central Mexico)

    Science.gov (United States)

    Lenhardt, Nils; Götz, Annette E.

    2015-04-01

    The geothermal potential of the Valley of Mexico has not been addressed in the past, although volcaniclastic settings in other parts of the world contain promising target reservoir formations. A first assessment of the geothermal potential of the Valley of Mexico is based on thermophysical data gained from outcrop analogues, covering all lithofacies types, and evaluation of groundwater temperature and heat flow values from literature. Furthermore, the volumetric approach of Muffler and Cataldi (1978) leads to a first estimation of ca. 4000 TWh (14.4 EJ) of power generation from Neogene volcanic rocks within the Valley of Mexico. Comparison with data from other sedimentary basins where deep geothermal reservoirs are identified shows the high potential of the Valley of Mexico for future geothermal reservoir utilization. The mainly low permeable lithotypes may be operated as stimulated systems, depending on the fracture porosity in the deeper subsurface. In some areas also auto-convective thermal water circulation might be expected and direct heat use without artificial stimulation becomes reasonable. Thermophysical properties of tuffs and siliciclastic rocks qualify them as promising target horizons (Lenhardt and Götz, 2015). The here presented data serve to identify exploration areas and are valuable attributes for reservoir modelling, contributing to (1) a reliable reservoir prognosis, (2) the decision of potential reservoir stimulation, and (3) the planning of long-term efficient reservoir utilization. References Lenhardt, N., Götz, A.E., 2015. Geothermal reservoir potential of volcaniclastic settings: The Valley of Mexico, Central Mexico. Renewable Energy. [in press] Muffler, P., Cataldi, R., 1978. Methods for regional assessment of geothermal resources. Geothermics, 7, 53-89.

  9. Multiple ash layers in late Quaternary sediments from the Central Indian Basin

    Science.gov (United States)

    Mascarenhas-Pereira, M. B. L.; Nagender Nath, B.; Iyer, S. D.; Borole, D. V.; Parthiban, G.; Jijin, R.; Khedekar, V.

    2016-04-01

    We have investigated three sediment cores collected from water depths > 5000 m along the transect 76°30‧E in close proximity to a fracture zone in the Central Indian Basin (CIB). The cores yielded five volcanic horizons of which four have visual and dispersed shards. Rhyolitic glass shards of bubble wall, platy, angular and blocky types were retrieved from various stratigraphic horizons in the cores. The abundance of glass shards, composition of bulk sediments, and 230Thexcess ages of the host sediments were used to distinguish the volcanic horizons. Of the four volcanic horizons, three are now newly reported and correspond to ages of ~ 85, 107-109 and 142-146 ka while the fourth horizon is of 70-75 ka. By using trace element ratios and Cr and Nb-based normative calculations, cryptotephra has been identified for the first time from the CIB sediment. The cryptotephra forms the fifth ash horizon and is of ~ 34 ka. A comparison with the published data on volcanic tephra in and around the Indian Ocean indicate the shard rich horizon (SRH) of 70-75 ka to resemble the Younger Toba Tuffs (YTT), while the other volcanic horizons that were deposited during different time periods do not correlate with any known marine or terrestrial records. These tephra layers have produced a tephrostratigraphic framework across the tectonically and volcanically complex regions of the CIB. Due to the lack of terrestrial equivalents of these tephra, it is hypothesized that the newly found volcanic horizons may have been derived from submarine volcanic eruptions. Multiple layers of submarine volcaniclastic deposits found at water depths as great as 5300 m reaffirm the growing belief that submarine phreatomagmatic eruptions are much more common in the intraplate region of the Indian Ocean than previously reported.

  10. Marine Ingressive Events Recorded in Epicontinental Sequences:Example from the Cretaceous Songliao Basin of NE China in Comparison with the Triassic Central Europe Basin of SW Germany

    Institute of Scientific and Technical Information of China (English)

    WANG Pujun; LIU Wanzhu; YIN Xiuzhen; SCHNEIDER Werner; MATTERN Frank

    2002-01-01

    Songliao Basin is filled predominantly with continental facies sediments including alluvial fan, fluvial plain, fan delta, lacustrine delta, shore - shallow lacustrine, beach salty flat, semi - deep to deep lacustrine, subaqueous gravity flow,lacustrine swamp and pyroclastic sediments. However, some event units were formed during lake - marine linking periods of the Mid - Cretaceous in the basin, which include black shales with high values for salinity (Sr/Ba) , alkalinity ( Ca + Mg)/(Si + Al) , reducibility (Ni + Zn)/Ga and sulfide sulfur as well as heavy isotopes. The Breitenholz -section to be represented for facies comparison with the Cretaceous evaporitic series in Northeast China is localized in Southwest Germany. Stratigraphically it belongs to the Crabfeld Formation of Keuper of the Germanic Triassic corresponding to Ladinian - Carnian of the international reference scale, and is generally called Lower Gipskeuper. The Germanic Triassic was deposited in the epicontinental (cratonic) central Europe Basin. It covered the area in between Great Britain, North Sea, Poland and Southern Germany. It is composed of cyclic deposits of multicolored mudstones, gypsum/anhydrite, and dolomite beds. The two cases of marine ingression - influenced sequences share some common features.

  11. Nature, source and composition of volcanic ash in sediments from a fracture zone trace of Rodriguez Triple Junction in the Central Indian Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Mascarenhas-Pereira, M.B.L.; Nath, B.N.; Borole, D.V.; Gupta, S.M.

    Volcanic glasses associated with pumice, micro nodules and palagonite like lithic fragments were recovered from a volcanic terrain in a fracture zone defined as Rodriguez Triple Junction trace in the Central Indian Basin. Morphologically, the tephra...

  12. Rainfall and surface kinematic conditions over central amazonia during ABLE 2B

    Science.gov (United States)

    Greco, Steven; Swap, Robert; Garstang, Michael; Ulanski, Stanley; Shipham, Mark

    1990-01-01

    Rainfall, rainfall systems, and surface kinematics of the central Amazon basin wet season are investigated using meteorological and chemical data collected during the wet season Amazon Boundary Layer Experiment (ABLE) near Manaus, Brazil. Through analysis of (GOES-West) imagery, it is determined that, based on location of the initial development, there are three main types of convective systems which influence a mesoscale network near Manaus, namely the Coastal Occurring Systems (COS), the Basin Occurring Systems (BOS), and the Locally Occurring Systems (LOS). Chemical analysis of rainwater delivered by these systems shows significant differences in concentrations of formate, acetate, pyruvate, sulfate, and hydrogen ion, and measurements of aerosol concentrations near Manaus show large influxes of aerosols into central Amazonia after passage of BOS and COS. Results of satellite based classification of the rain-producing systems are discussed.

  13. The Tunas Formation (Permian) in the Sierras Australes foldbelt, east central Argentina: evidence for syntectonic sedimentation in a foreland basin

    Science.gov (United States)

    Lopez-Gamundi, O. R.; Conaghan, P. J.; Rossello, E. A.; Cobbold, P. R.

    1995-04-01

    The Tunas Formation, extensively exposed in the Sierras Australes foldbelt of eastern central Argentina, completes the sedimentation of the Gondwanan (Late Carboniferous-Permian) sequence, locally known as the Pillahuincó Group. The underlying units of the Group show an integrated depositional history which can be explained in terms of glaciomarine sedimentation (Sauce Grande Formation) and postglacial transgression (Piedra Azul and Bonete Formations). This succession also has a rather uniform quartz-rich, sand-sized composition indicative of a cratonic provenance from the Tandilia Massif to the northeast. Early to Late Permian deformation folded and thrusted the southwestern basin margin (Sierras Australes) and triggered the deposition of a 1,500 m — thick, synorogenic prograding wedge, the Tunas Formation, in the adjacent foreland basin (Sauce Grande or Claromecó Basin). Sandstone detrital modes for the Tunas deposits show moderate to low contents of quartz and abundant lithics, mostly of volcanic and metasedimentary origin. Paleocurrents are consistently from the SW. Tuffs interbedded with sandstones in the upper half of Tunas Formation (Early — early Late? Permian) are interpreted as being derived from volcanic glass-rich tuffs settled in a body of water. Extensive rhyolitic ignimbrites and consanguineous airborne tuffaceous material erupted in the northern Patagonian region during that period. The age constraints and similarities in composition between these volcanics and the tuffaceous horizons present in the Sauce Grande, Parana and Karoo Basins suggest a genetic linkage between these two episodes. The intimate relationship between volcanic activity inboard of the paleo-Pacific margin, deformation in the adjacent orogenic belt and subsidence and sedimentation in the contiguous foreland basin constitutes a common motif in the Sauce Grande and Karoo Basins of southwestern Gondwana.

  14. Exhumation of the Panama basement complex and basins: Implications for the closure of the Central American seaway

    Science.gov (United States)

    Ramírez, Diego A.; Foster, David A.; Min, Kyoungwon; Montes, Camilo; Cardona, Agustín.; Sadove, Gephen

    2016-05-01

    The emergence of the Central American isthmus occurred episodically from Eocene to Pliocene time and was caused by a series of tectonic and volcanic processes. Results from zircon U-Pb geochronology, zircon (U-Th)/He (ZHe) and apatite (U-Th)/He (AHe) thermochronology, and zircon Lu-Hf isotopic data from sedimentary (sandstones and recent river sands) and plutonic rocks from the Azuero Peninsula and Central Panama document the exhumation and uplift history of the Panamanian basement complex. Our data support previous paleobotanical and thermochronological studies that suggest that by middle Eocene time some areas of Central Panama and Azuero Peninsula were exposed above sea level as a series of islands surrounded by shallow open marine waters. The Gatuncillo, Cobachón and Tonosí formations were deposited during this partial emergence. Transtension in the Oligocene-early Miocene produced various pull-apart basins (e.g., the Canal Basin) and local uplift that exhumed the Eocene strata (Gatuncillo and Cobachón formations). This event probably reduced circulation between the Pacific Ocean and the Caribbean Sea. The Tonosí Formation records late Miocene to Pleistocene cooling and exhumation, which may be related to uplift above the subducting Coiba Ridge. These results suggest that the emergence of the Isthmus of Panama followed a series of diachronous events that led to the final closure of the Central American seaway.

  15. Two-stage formation model of the Junggar basin basement: Constraints to the growth style of Central Asian Orogenic Belt

    Science.gov (United States)

    He, Dengfa

    2016-04-01

    Junggar Basin is located in the central part of the Central Asian Orogenic Belt (CAOB). Its basement nature is a highly controversial scientific topic, involving the basic style and processes of crustal growth. Some researchers considered the basement of the Junggar Basin as a Precambrian continental crust, which is not consistent with the petrological compositions of the adjacent orogenic belts and the crust isotopic compositions revealed by the volcanic rocks in the basin. Others, on the contrary, proposed an oceanic crust basement model that does not match with the crustal thickness and geophysical characteristics of the Junggar area. Additionally, there are several viewponits, such as the duplex basement with the underlying Precambrian crystalline rocks and the overlying pre-Carboniferous folded basement, and the collaged basement by the Precambrian micro-continent block in the central part and the Hercynian accretionary folded belts circling it. Anyway, it is necessary to explain the property of basement rock, its strong inhomogeneous compositions as well as the geophysical features. In this paper, based on the borehole data from more than 300 industry wells drilled into the Carboniferous System, together with the high-resolution gravity and magnetic data (in a scale of 1:50,000), we made a detailed analysis of the basement structure, formation timing and processes and its later evolution on a basis of core geochemical and isotopic analysis. Firstly, we defined the Mahu Pre-Cambrian micro-continental block in the juvenile crust of Junggar Basin according to the Hf isotopic analysis of the Carboniferous volcanic rocks. Secondly, the results of the tectonic setting and basin analysis suggest that the Junggar area incorporates three approximately E-W trending island arc belts (from north to south: Yemaquan- Wulungu-Chingiz, Jiangjunmiao-Luliang-Darbut and Zhongguai-Mosuowan- Baijiahai-Qitai island arcs respectively) and intervened three approximately E-W trending

  16. Amazon River carbon dioxide outgassing fuelled by wetlands

    Science.gov (United States)

    Abril, Gwenaël; Martinez, Jean-Michel; Artigas, L. Felipe; Moreira-Turcq, Patricia; Benedetti, Marc F.; Vidal, Luciana; Meziane, Tarik; Kim, Jung-Hyun; Bernardes, Marcelo C.; Savoye, Nicolas; Deborde, Jonathan; Souza, Edivaldo Lima; Albéric, Patrick; Landim de Souza, Marcelo F.; Roland, Fabio

    2014-01-01

    River systems connect the terrestrial biosphere, the atmosphere and the ocean in the global carbon cycle. A recent estimate suggests that up to 3 petagrams of carbon per year could be emitted as carbon dioxide (CO2) from global inland waters, offsetting the carbon uptake by terrestrial ecosystems. It is generally assumed that inland waters emit carbon that has been previously fixed upstream by land plant photosynthesis, then transferred to soils, and subsequently transported downstream in run-off. But at the scale of entire drainage basins, the lateral carbon fluxes carried by small rivers upstream do not account for all of the CO2 emitted from inundated areas downstream. Three-quarters of the world's flooded land consists of temporary wetlands, but the contribution of these productive ecosystems to the inland water carbon budget has been largely overlooked. Here we show that wetlands pump large amounts of atmospheric CO2 into river waters in the floodplains of the central Amazon. Flooded forests and floating vegetation export large amounts of carbon to river waters and the dissolved CO2 can be transported dozens to hundreds of kilometres downstream before being emitted. We estimate that Amazonian wetlands export half of their gross primary production to river waters as dissolved CO2 and organic carbon, compared with only a few per cent of gross primary production exported in upland (not flooded) ecosystems. Moreover, we suggest that wetland carbon export is potentially large enough to account for at least the 0.21 petagrams of carbon emitted per year as CO2 from the central Amazon River and its floodplains. Global carbon budgets should explicitly address temporary or vegetated flooded areas, because these ecosystems combine high aerial primary production with large, fast carbon export, potentially supporting a substantial fraction of CO2 evasion from inland waters.

  17. Programming Amazon EC2

    CERN Document Server

    Vliet, Jurg

    2011-01-01

    If you plan to use Amazon Web Services to run applications in the cloud, the end-to-end approach in this book will save you needless trial and error. You'll find practical guidelines for designing and building applications with Amazon Elastic Compute Cloud (EC2) and a host of supporting AWS tools, with a focus on critical issues such as load balancing, monitoring, and automation. How do you move an existing application to AWS, or design your application so that it scales effectively? How much storage will you require? Programming Amazon EC2 not only helps you get started, it will also keep y

  18. Ocorrência do molusco asiático Corbicula fluminea (Müller, 1774 (Bivalvia, Corbiculidae no baixo rio Negro, Amazônia central Occurrence of the Asian mollusc Corbicula fluminea (Müller, 1774 (Bivalvia, Corbiculidae in the lower Rio Negro, Central Amazon Region, Brazil

    Directory of Open Access Journals (Sweden)

    Daniel Mansur Pimpão

    2008-01-01

    Full Text Available O rio Negro é um dos maiores afluentes do rio Amazonas, mas poucos moluscos foram registrados até o momento para aquele rio, representados apenas por gastrópodes. Foi registrada a presença do molusco bivalve exótico Corbicula fluminea na margem esquerda do baixo rio Negro, no lago do Tupé e no Catalão - margem direita do rio Negro, todas localidades no município de Manaus, Brasil. O registro foi realizado por meio da coleta de conchas e espécimes vivos. É o primeiro registro de C. fluminea para o estado do Amazonas e Amazônia central.The Rio Negro is one of the biggest Rio Amazonas tributaries. Few molluscs have been registered to that river yet, represented only by gastropods. It is reported the occurrence of the exotic bivalve mollusc Corbicula fluminea in left bank margin of Rio Negro, Lago do Tupé and Catalão - right bank margin of Rio Negro, all localities in the municipality of Manaus, Brazil. The species is recorded by a collection of shells and specimens alive. This is the first occurrence of C. fluminea in the Amazon State and Central Amazon.

  19. The Wavelet ToolKat: A set of tools for the analysis of series through wavelet transforms. Application to the channel curvature and the slope control of three free meandering rivers in the Amazon basin.

    Science.gov (United States)

    Vaudor, Lise; Piegay, Herve; Wawrzyniak, Vincent; Spitoni, Marie

    2016-04-01

    The form and functioning of a geomorphic system result from processes operating at various spatial and temporal scales. Longitudinal channel characteristics thus exhibit complex patterns which vary according to the scale of study, might be periodic or segmented, and are generally blurred by noise. Describing the intricate, multiscale structure of such signals, and identifying at which scales the patterns are dominant and over which sub-reach, could help determine at which scales they should be investigated, and provide insights into the main controlling factors. Wavelet transforms aim at describing data at multiple scales (either in time or space), and are now exploited in geophysics for the analysis of nonstationary series of data. They provide a consistent, non-arbitrary, and multiscale description of a signal's variations and help explore potential causalities. Nevertheless, their use in fluvial geomorphology, notably to study longitudinal patterns, is hindered by a lack of user-friendly tools to help understand, implement, and interpret them. We have developed a free application, The Wavelet ToolKat, designed to facilitate the use of wavelet transforms on temporal or spatial series. We illustrate its usefulness describing longitudinal channel curvature and slope of three freely meandering rivers in the Amazon basin (the Purus, Juruá and Madre de Dios rivers), using topographic data generated from NASA's Shuttle Radar Topography Mission (SRTM) in 2000. Three types of wavelet transforms are used, with different purposes. Continuous Wavelet Transforms are used to identify in a non-arbitrary way the dominant scales and locations at which channel curvature and slope vary. Cross-wavelet transforms, and wavelet coherence and phase are used to identify scales and locations exhibiting significant channel curvature and slope co-variations. Maximal Overlap Discrete Wavelet Transforms decompose data into their variations at a series of scales and are used to provide

  20. Hydrogeology and hydrogeochemistry at a site of strategic importance: the Pareja Limno-reservoir drainage basin (Guadalajara, central Spain)

    Science.gov (United States)

    Molina-Navarro, Eugenio; Sastre-Merlín, Antonio; Vicente, Rosa; Martínez-Pérez, Silvia

    2014-08-01

    A small calcareo