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Sample records for chilean volcanic soils

  1. Preparative treatment with NaOH to selectively concentrate iron oxides of a Chilean volcanic soil material to produce effective heterogeneous Fenton catalyst

    International Nuclear Information System (INIS)

    A Chilean volcanic Ultisol material was first size-fractionated so as to obtain the fraction with mean particle sizes φ  − 1 NaOH, in an attempt to evaluate the effectiveness of the selective chemical dissolution to concentrate iron oxides, as a preparation procedure before using the materials as heterogeneous Fenton catalysts. The effects of those treatments on the iron oxides mineralogy were monitored with Mössbauer spectroscopy. The NaOH-treated samples were tested as catalysts towards the H2O2 decomposition. Three or five sequential NaOH treatments were found to be comparably effective, by concentrating nearly the same proportion of iron oxides in the remaining solid phase (25.1 ± 0.4 and 23.3 ± 0.2 mass%, respectively). 298 K-Mössbauer patterns were similar for both samples, with a central (super)paramagnetic Fe3 +  doublet and a broad sextet, assignable to several closely coexisting magnetically ordered forms of iron oxides. Despite of this nearly similar effect of the two treatments, the Ultisol material treated three times with NaOH presents higher heterogeneous catalytic efficiency and is more suitable to decompose H2O2 than that with five treatments.

  2. Young volcanoes in the Chilean Southern Volcanic Zone: A statistical approach to eruption prediction based on time series

    Science.gov (United States)

    Dzierma, Y.; Wehrmann, H.

    2010-03-01

    Forecasting volcanic activity has long been an aim of applied volcanology with regard to mitigating consequences of volcanic eruptions. Effective disaster management requires both information on expected physical eruption behaviour such as types and magnitudes of eruptions as typical for the individual volcano, usually reconstructed from deposits of past eruptions, and the likelihood that a new eruption will occur within a given time. Here we apply a statistical procedure to provide a probability estimate for future eruptions based on eruption time series, and discuss the limitations of this approach. The statistical investigation encompasses a series of young volcanoes of the Chilean Southern Volcanic Zone. Most of the volcanoes considered have been active in historical times, in addition to several volcanoes with a longer eruption record from Late-Pleistocene to Holocene. Furthermore, eruption rates of neighbouring volcanoes are compared with the aim to reveal possible regional relations, potentially resulting from local to medium-scale tectonic dynamics. One special focus is directed to the two currently most active volcanoes of South America, Llaima and Villarrica, whose eruption records comprise about 50 historical eruptions over the past centuries. These two front volcanoes are considered together with Lanín Volcano, situated in the back-arc of Villarrica, for which the analysis is based on eight eruptions in the past 10 ka. For Llaima and Villarrica, affirmed tests for independence of the repose times between successive eruptions permit to assume Poisson processes; which is hampered for Lanín because of the more limited availability of documented eruptions. The assumption of stationarity reaches varying degrees of confidence depending on the time interval considered, ameliorating towards the more recent and hence probably more complete eruption record. With these pre-requisites of the time series, several distribution functions are fit and the goodness of

  3. Comparison of water availability effect on ammonia-oxidizing bacteria and archaea in microcosms of a Chilean semiarid soil

    OpenAIRE

    Bustamante, Mauricio; Verdejo, Valentina; Zúñiga, Catalina; Espinosa, Fernanda; Orlando, Julieta; Carú, Margarita

    2012-01-01

    Water availability is the main limiting factor in arid soils; however, few studies have examined the effects of drying and rewetting on nitrifiers from these environments. The effect of water availability on the diversity of ammonia-oxidizing bacteria (AOB) and archaea (AOA) from a semiarid soil of the Chilean sclerophyllous matorral was determined by microcosm assays. The addition of water every 14 days to reach 60% of the WHC significantly increased nitrate content in rewetted soil microcos...

  4. Comparison of water availability effect on ammonia-oxidizing bacteria and archaea in microcosms of a Chilean semiarid soil

    OpenAIRE

    JulietaOrlando

    2012-01-01

    Water availability is the main limiting factor in arid soils; however few studies have examined the effects of drying and rewetting on nitrifiers from these environments. The effect of water availability on the diversity of ammonia-oxidizing bacteria (AOB) and archaea (AOA) from a semiarid soil of the Chilean sclerophyllous matorral was determined by microcosm assays. The addition of water every 14 days to reach 60% of the WHC significantly increased nitrate content in rewetted soil microcosm...

  5. Micromorphological Characterization of Some Volcanic Soil In West Java

    OpenAIRE

    Mahfud Arifin; Rina Devnita

    2014-01-01

    http://dx.doi.org/10.17014/ijog.vol3no4.20082Micromorphological characterization has been studied on six pedons of soils developing in volcanic materials in West Java. The pedons represent deposits of different volcanoes (Mount Tangkuban Perahu, Mount Patuha and Mount Papandayan) with different ages (Pleistocene, Holocene) within two types of volcanisms (andesitic, basaltic), and three agroclimatic zones (A, B1, B2). Undisturbed soil samples were taken from each identifiable horizon for thin ...

  6. Aluminium fractionation of European volcanic soils by selective dissolution techniques

    NARCIS (Netherlands)

    Garcia-Rodeja, E.; Novoa, J.C.; Pontevedra, X.; Martinez-Cortizas, A.; Buurman, P.

    2004-01-01

    Several selective dissolution methods were used to differentiate Al forms in 12 soils formed from volcanic materials (64 andic, vitric and organic horizons) in Iceland, Azores (Portugal), Tenerife (Spain) and Italy. The soils differ in many properties because of differences in parent materials, clim

  7. Micromorphological Characterization of Some Volcanic Soil In West Java

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    Mahfud Arifin

    2014-06-01

    Full Text Available http://dx.doi.org/10.17014/ijog.vol3no4.20082Micromorphological characterization has been studied on six pedons of soils developing in volcanic materials in West Java. The pedons represent deposits of different volcanoes (Mount Tangkuban Perahu, Mount Patuha and Mount Papandayan with different ages (Pleistocene, Holocene within two types of volcanisms (andesitic, basaltic, and three agroclimatic zones (A, B1, B2. Undisturbed soil samples were taken from each identifiable horizon for thin section preparations. Observations were carried out by means of a magnifying lens, binocular stereomicroscope, polarization microscope, and scanning electron microscope (SEM. The result demonstrates that micromorphological characteristics of volcanic soils developing from different ages, types of parent material, and climate were different through their c/f related distribution 2µ patterns, c/f ratios, sorting, infillings and coatings of voids, and microstructure.  

  8. Improving Water Quality Through Better Soil Management in Chilean Vineyard Plantations

    International Nuclear Information System (INIS)

    Sixty per cent of arable land in Chile is affected by erosion, the rate having increased by almost 50% during the past 30 years. In Central Chile, a shortage of flat land has increasingly compelled wine growers to plant vineyards on the hillsides. This has resulted in further soil erosion and degradation that already covers 20% of the region, equivalent to 90,500 ha. The sustainability of vineyard operations is further aggravated by the negative impact that this erosion has on downstream water quality, caused by herbicides and nutrients being carried down the hillsides by excess water runoff. The central region of Chile has therefore placed priority on the challenge to develop and implement appropriate land management practices designed to improve water quality and minimise soil erosion in vineyards. Through three consecutive IAEA technical cooperation projects, the Agriculture Section of the Chilean Nuclear Energy Commission, in cooperation with the Faculty of Agricultural Sciences at the University of Chile and the Agriculture and Livestock Service, compared current soil management practices in vineyards in the Apalta valley 200 km south of Santiago de Chile. The fallout radionuclide, Beryllium-7 (7Be), was used as a tracer to estimate short-term (less than a month) soil erosion and deposition across agricultural landscapes. Herbicides labelled with the radioactive carbon-14 (14C) were used to determine the mobility of herbicides during erosion events and hence their influence on water quality. The projects compared planting on terraces with the traditional downslope rows, both with only scarce soil cover during the rainy season. Net annual rates of soil loss from the terraced site (76 t/ha) were only about 7% less than those from the downslope site (82 t/ha), indicating that soil losses were substantial on both terraces and downslopes. The lack of sufficient cover particularly during the first month of the rainy seasons could explain the severity of the observed

  9. Mercury content in volcanic soils across Europe and its relationship with soil properties

    Energy Technology Data Exchange (ETDEWEB)

    Pena-Rodriguez, Susana; Fernandez-Calvino, David; Arias-Estevez, Manuel; Novoa-Munoz, Juan Carlos [Vigo Univ., Ourense (Spain). Area de Edafoloxia e Quimica Agricola; Pontevedra-Pombal, Xabier; Taboada, Teresa; Martinez-Cortizas, Antonio; Garcia-Rodeja, Eduardo [Universidad de Santiago, Coruna (Spain). Dept. Edafoloxia e Quimica Agricola

    2012-04-15

    Volcanoes are a natural source of Hg, whose deposition can occur in neighbouring soils. This study examines the role of soil compounds in the geochemical behaviour of total Hg (Hg{sub T}) in volcanic soils. An estimation of Hg from lithological origin is also assessed to ascertain the relevance of other sources in Hg{sub T} accumulated in volcanic soils. Twenty soil profiles developed from volcanic materials and located across European volcanic regions were selected for this study. The general characterisation of soils included total C, N and S content and Al and Fe distribution determined using traditional methods. The total content of major and trace elements was determined using X-ray fluorescence spectrometry (XRF). The total Hg content of soil samples was measured with atomic absorption spectroscopy using a solid sample Hg analyser. Lithogenic Hg was calculated in the uppermost soil considering Al, Ti and Zr as conservative reference elements. Several statistical analyses (Pearson correlations, Mann-Whitney tests, stepwise multiple regressions and analysis of variance) were carried to ascertain the role of soil parameters and characteristics in the Hg accumulation in volcanic soils. The total Hg ranged from 3.0 to 640 ng g{sup -1} and it tended to diminish with soil depth except in some soils where the lithological discontinuities resulted in high values of Hg{sub T} in the Bw horizons. More than 75% of the Hg{sub T} variance could be attributed to distinct contents of organic matter, Al- and Fe-humus complexes and inorganic non-crystalline Al and Fe compounds in ''andic'', ''vitric'' and ''non-andic'' horizons. The degree of pedogenetic soil evolution notably influenced the Hg{sub T} soil content. Lithogenic Hg (1.6-320 ng g{sup -1}) was correlated with Al-humus complexes and clay content, suggesting the relevance of pedogenetic processes, whereas exogenic Hg (1.4-180 ng g{sup -1}) was correlated

  10. Volcanism and soil mercury on Mars - Consequences for terrestrial microorganisms

    Science.gov (United States)

    Siegel, B. Z.; Siegel, S. M.

    1978-01-01

    An earth-Mars depletion formula proposed by Anders and Owen for volatiles is used to calculate a range of putative Hg levels for Martian volcanic soils based upon analyzed samples from Hawaii. The range is about 50-150 microgram per kg. When applied either in conventional or special media (e.g., basalt powder), these levels of Hg are effective inhibitors of the growth of earth microorganisms. Taken together with other hostile chemical and physical factors, volcanic toxicants would appear to provide a further deterrent to the accidental establishment of terrestrial microbiota on Mars.

  11. REGIONAL SOIL WATER RETENTION IN THE CONTIGUOUS US: SOURCES OF VARIABILITY AND VOLCANIC SOIL EFFECTS

    Science.gov (United States)

    Water retention of mineral soil is often well predicted using algorithms (pedotransfer functions) with basic soil properties but the spatial variability of these properties has not been well characterized. A further source of uncertainty is that water retention by volcanic soils...

  12. Statistical eruption forecast for the Chilean Southern Volcanic Zone: typical probabilities of volcanic eruptions as baseline for possibly enhanced activity following the large 2010 Concepción earthquake

    Directory of Open Access Journals (Sweden)

    Y. Dzierma

    2010-10-01

    Full Text Available A probabilistic eruption forecast is provided for ten volcanoes of the Chilean Southern Volcanic Zone (SVZ. Since 70% of the Chilean population lives in this area, the estimation of future eruption likelihood is an important part of hazard assessment. After investigating the completeness and stationarity of the historical eruption time series, the exponential, Weibull, and log-logistic distribution functions are fit to the repose time distributions for the individual volcanoes and the models are evaluated. This procedure has been implemented in two different ways to methodologically compare details in the fitting process. With regard to the probability of at least one VEI ≥ 2 eruption in the next decade, Llaima, Villarrica and Nevados de Chillán are most likely to erupt, while Osorno shows the lowest eruption probability among the volcanoes analysed. In addition to giving a compilation of the statistical eruption forecasts along the historically most active volcanoes of the SVZ, this paper aims to give "typical" eruption probabilities, which may in the future permit to distinguish possibly enhanced activity in the aftermath of the large 2010 Concepción earthquake.

  13. Carbon Stabilization in Wet Tropical Forest Volcanic Soils

    Science.gov (United States)

    Marin-Spiotta, E.; Chadwick, O.; Kramer, M.

    2008-12-01

    Volcanic soils, particularly Andisols, have high carbon storage capacities due to the accumulation of highly reactive, non-crystalline minerals. Previous research along a pedogenic chronosequence on volcanic lava in Hawai'i found that soils in the intermediate weathering stage, dominated by allophane, contained the largest soil C stocks with slowest turnover rates. Potential mechanisms for long-term soil C stabilization include an accumulation of chemically recalcitrant C, microenvironmental conditions unfavorable for decomposition, and strong sorption of soluble and otherwise labile C to mineral and/or metals. In well-drained soils in wet climates, dissolved organic matter (DOM) is a likely main pathway for the transport of C from the zones of highest microbial activity to deeper mineral horizons. To address the production, transformation, and fate of dissolved organic matter (DOM), we have installed tension and zero tension lysimeters throughout sequentially deeper organic and mineral horizons in an intermediate aged soil (ca. 350k years) under wet (ca. 3000 mm mean annual rainfall) native tropical forest in Hawai'i. The soils are characterized by thick O horizons and Bh horizons 20-30 cm deep, followed by mineral horizons showing redoximorphic features. Bulk soil carbon to nitrogen ratios increase with soil depth, matching that of DOM in the surface organic horizons at 40-50 cm depth. Low pH does not seem to explain this accumulation of C-rich, N-depleted OM, as soils become less acidic with depth. Soil C:N are positively correlated with alumina, oxalate-extractable Al, and dithionite citrate-extractable Al. The greatest source of DOC is the forest floor (Oie), followed by the Oa horizon, and concentrations decrease significantly in the mineral horizons. DOC concentrations increase with total dissolved Al and Fe in the Oie horizon, and with total Fe in solution in the Bg horizon. In the Bh horizon, DOM C:N are negatively correlated with total Al and Fe in

  14. Genesis of petroduric and petrocalcic horizons in Latinamerica volcanic soils

    Science.gov (United States)

    Quantin, Paul

    2010-05-01

    Introduction. In Latinamerica, from Mexico to Chile, there are indurated volcanic soils horizons, named 'tepetate' in Mexico or cangahua in the Andes Mountains. Apart from original volcanic tuffs, these horizons were produced by pedogenesis: either through a former weathering of volcanic ash layers into fragic and later to petrocalcic horizons; or after a former soil formation through a second process of transformation from clayey volcanic soils to silicified petroduric horizons. This oral presentation will briefly deal with the formation of petroduric horizons in Mexico and petrocalcic horizon in Ecuador. Petroduric horizon genesis in Mexico. A soil climato-toposequence, near to Veracruz (Rossignol & Quantin, 1997), shows downwards an evolution from a ferralic Nitisol to a petroduric Durisol. A Durisol profile comports these successive horizons: at the top A and Eg, then columnar Btg-sim, laminar Bt-sim , prismatic Bsim, plinthite Cg, over andesite lava flow. Among its main features are especially recorded: clay mineralogy, microscopy and HRTEM. These data show: an increase in cristobalite at the expenses of 0.7 nm halloysite in Egsiltans, laminar Bt-sim, around or inside the columns or prisms of Btg-sim and Bsimhorizons. HRTEM (Elsass & al 2000) on ultra thin sections reveals an 'epigenesis' of clay sheets by amorphous silica, to form successively A-opal, Ct-opal and microcrystalline cristobalite. From these data and some groundwater chemical analyses, a scenario of duripan formation from a past clayey Nitisol is inferred: clay eluviation-illuviation process? alternate redoximorphy? clay degradation, Al leaching and Si accumulation, to form successively A-opal, Ct-opal and cristobalite. Petrocalcic horizon genesis in Ecuador. A soil climato-toposequence on pyroclastic flows, near to Bolivar in Ecuador (Quantin & Zebrowski, 1997), shows downwards the evolution from fragic-eutric-vitric Cambisols to petrocalcic-vitric Phaeozems, at the piedmont under semi

  15. Adsorption of 2,4-Dichlorophenoxyacetic Acid onto Volcanic Ash Soils:

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    Ei Ei Mon

    2009-01-01

    Full Text Available The quantification of the linear adsorption coefficient (Kd for soils plays a vital role to predict fate and transport of pesticides in the soil-water environment. In this study, we measured Kd values for 2,4-Dichlorophenoxyacetic acid (2,4-D adsorption onto Japanese volcanic ash soils with different amount of soil organic matter (SOM in batch experiments under different pH conditions. All measurements followed well both linear and Freundlich adsorption isotherms. Strong correlations were found between measured Kd values and pH as well as SOM. The 2,4-D adsorption increased with decreasing pH and with increasing SOM. Based on the data, a predictive Kd equation for volcanic ash soils, log (Kd = 2.04 - 0.37 pH + 0.91 log (SOM, was obtained by the multiple regression analysis. The predictive Kd equation was tested against measured 2,4-D sorption data for other volcanic ash soils and normal mineral soils from literature. The proposed Kd equation well predicted Kd values for other volcanic ash soils and slightly over- or under-predicted Kd values for normal mineral soils. The proposed Kd equation performed well against volcanic ash soils from different sites and countries, and is therefore recommended for predicting Kd values at different pH and SOM conditions for volcanic ash soils when calculating and predicting 2,4-D mobility and fate in soil and groundwater.

  16. Soil microbial communities as suitable bioindicators of trace metal pollution in agricultural volcanic soils

    Science.gov (United States)

    Parelho, Carolina; dos Santos Rodrigues, Armindo; do Carmo Barreto, Maria; Gonçalo Ferreira, Nuno; Garcia, Patrícia

    2015-04-01

    Summary: The biological, chemical and physical properties of soil confer unique characteristics that enhance or influence its overall biodiversity. The adaptive character of soil microbial communities (SMCs) to metal pollution allows discriminating soil health, since changes in microbial populations and activities may function as excellent indicators of soil pollutants. Volcanic soils are unique naturally fertile resources, extensively used for agricultural purposes and with particular physicochemical properties that may result in accumulation of toxic substances, such as trace metals (TM). In our previous works, we identified priority TM affecting agricultural Andosols under different agricultural land uses. Within this particular context, the objectives of this study were to (i) assess the effect of soil TM pollution in different agricultural systems (conventional, traditional and organic) on the following soil properties: microbial biomass carbon, basal soil respiration, metabolic quotient, enzymatic activities (β-glucosidase, acid phosphatase and dehydrogenase) and RNA to DNA ratio; and (ii) evaluate the impact of TM in the soil ecosystem using the integrated biomarker response (IBR) based on a set of biochemical responses of SMCs. This multi-biomarker approach will support the development of the "Trace Metal Footprint" for different agricultural land uses in volcanic soils. Methods: The study was conducted in S. Miguel Island (Azores, Portugal). Microbial biomass carbon was measured by chloroform-fumigation-incubation-assay (Vance et al., 1987). Basal respiration was determined by the Jenkinson & Powlson (1976) technique. Metabolic quotient was calculated as the ratio of basal respiration to microbial biomass C (Sparkling & West, 1988). The enzymatic activities of β-glucosidase and acid phosphatase were determined by the Dick et al. (1996) method and dehydrogenase activity by the Rossel et al. (1997) method. The RNA and DNA were co-extracted from the same

  17. Eruptive stratigraphy of the Tatara-San Pedro complex, 36°S, sourthern volcanic zone, Chilean Andes: reconstruction method and implications for magma evolution at long-lived arc volcanic centers

    Science.gov (United States)

    Dungan, M.A.; Wulff, A.; Thompson, R.

    2001-01-01

    The Quaternary Tatara-San Pedro volcanic complex (36°S, Chilean Andes) comprises eight or more unconformity-bound volcanic sequences, representing variably preserved erosional remnants of volcanic centers generated during 930 ky of activity. The internal eruptive histories of several dominantly mafic to intermediate sequences have been reconstructed, on the basis of correlations of whole-rock major and trace element chemistry of flows between multiple sampled sections, but with critical contributions from photogrammetric, geochronologic, and paleomagnetic data. Many groups of flows representing discrete eruptive events define internal variation trends that reflect extrusion of heterogeneous or rapidly evolving magna batches from conduit-reservoir systems in which open-system processes typically played a large role. Long-term progressive evolution trends are extremely rare and the magma compositions of successive eruptive events rarely lie on precisely the same differentiation trend, even where they have evolved from similar parent magmas by similar processes. These observations are not consistent with magma differentiation in large long-lived reservoirs, but they may be accommodated by diverse interactions between newly arrived magma inputs and multiple resident pockets of evolved magma and / or crystal mush residing in conduit-dominated subvolcanic reservoirs. Without constraints provided by the reconstructed stratigraphic relations, the framework for petrologic modeling would be far different. A well-established eruptive stratigraphy may provide independent constraints on the petrologic processes involved in magma evolution-simply on the basis of the specific order in which diverse, broadly cogenetic magmas have been erupted. The Tatara-San Pedro complex includes lavas ranging from primitive basalt to high-SiO2 rhyolite, and although the dominant erupted magma type was basaltic andesite ( 52-55 wt % SiO2) each sequence is characterized by unique proportions of

  18. Comparison of water availability effect on ammonia-oxidizing bacteria and archaea in microcosms of a Chilean semiarid soil

    Directory of Open Access Journals (Sweden)

    Mauricio eBustamante

    2012-08-01

    Full Text Available Water availability is the main limiting factor in arid soils; however few studies have examined the effects of drying and rewetting on nitrifiers from these environments. The effect of water availability on the diversity of ammonia-oxidizing bacteria (AOB and archaea (AOA from a semiarid soil of the Chilean sclerophyllous matorral was determined by microcosm assays. The addition of water every 14 days to reach 60% of the WHC significantly increased nitrate content in rewetted soil microcosms (p<0.001. This stimulation of net nitrification by water addition was inhibited by acetylene addition at 100 Pa. The composition of AOA and AOB assemblages from the soils microcosms was determined by clone sequencing of amoA genes (A-amoA and B-amoA, respectively, and the 16S rRNA genes specific for β-proteobacteria (beta-amo. Sequencing of beta-amo genes has revealed representatives of Nitrosomonas and Nitrosospira while B-amoA clones consisted only of Nitrosospira sequences. Furthermore, all clones from the archaeal amoA gene library (A-amoA were related to ‘mesophilic Crenarchaeota’ sequences (actually, reclassified as the phylum Thaumarchaeota. The effect of water availability on both microbial assemblages structure was determined by T-RFLP profiles using the genetic markers amoA for archaea, and beta-amo for bacteria. While AOA showed fluctuations in some T-RFs, AOB structure remained unchanged by water pulses. The relative abundance of AOA and AOB was estimated by the Most Probable Number coupled to Polymerase Chain Reaction (MPN-PCR assay. AOB was the predominant guild in this soil and higher soil water content did not affect their abundance, in contrast to AOA, which slightly increased under these conditions. Therefore, these results suggest that water addition to these semiarid soil microcosms could favor archaeal contribution to ammonium oxidation.

  19. Characterization of volcanic ash soils in southwestern Tanzania: Morphology, physicochemical properties, and classification

    OpenAIRE

    MSANYA, Balthazar Michael; OTSUKA, Hiroo; Araki, Shigeru; Fujitake, Nobuhide

    2007-01-01

    This study examined the characteristics of volcanic ash soils in southwestern Tanzania. Twelve pedons of volcanic origin were studied, and 66 soil samples were analyzed. Soil morphology revealed volcanic ash layers of varying thicknesses. Most pedons had a dark thick humus surface and buried A, AB, and BA horizons with melanic indices of 1.7 or less. Except in two pedons, the NaF pH was 9.4 or more, reflecting an exchange complex dominated by amorphous materials and/or Al–humus complexes. The...

  20. Landscape formation and soil genesis in volcanic parent materials in humid tropical lowlands of Costa Rica.

    NARCIS (Netherlands)

    Nieuwenhuyse, A.

    1996-01-01

    The influence of volcanism on landscape genesis, and formation of soils on volcanic parent material was studied in the Atlantic lowland of Costs Rica. This lowland is a subduction basin of tectonic origin, in which thick alluvial and marine sediments are accumulated. At its southwestern side it is b

  1. PROPERTIES AND MANAGEMENT IMPLICATIONS OF SOILS FORMED FROM VOLCANIC MATERIALS IN LEMBANG AREA, WEST JAVA

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    Edi Yatno

    2016-10-01

    Full Text Available Soils formed from volcanic materials have a high potential for agricultural development, especially for horticultural crops, tea, and pine trees. Data on the characteristics of these soils are important for the management planning. Six representative soil profiles developed on andesitic volcanic ash and tuff in Lembang area, West Java were studied to determine the soil physical, chemical, and mineralogical properties, to study the relationship between the soil properties, and to classify the soils according to the Soil Taxonomy. The results indicated that all the soils had very deep (>150 cm solum. In general, the volcanic ash soils were darker colored, more granular, more friable, less sticky and less plastic than the volcanic tuff soils. Physically, the ash soils had lower bulk density (0.44-0.73 mg m-3 and higher available water content (13-33% than the tuff soils. Bulk density decreased with increasing allophane. Chemically, the ash soils had higher pHNaF (mostly > 10, higher organic carbon (4.3-6.8% in upper horizons, higher CEC (20- 44 cmolc kg-1, and higher P retention (> 85% than the tuff soils. P retention logarithmically increased with increasing oxalate extractable Al and allophane. The sand fractions of the ash soils were dominated by hornblende, while the tuff soils were predominantly composed of opaque minerals. In the clay fractions, the ash soils were dominated by allophane, whereas the tuff soils showed high contents of gibbsite and metahalloysite. Soils developed on volcanic ash were classified as Thaptic Hapludands and Typic Melanudands, while soils formed from volcanic tuff were classified as Andic Dystrudepts. The low bulk density and friable consistency of the soils contributed to favorable soil tilth. However, high P retention and Al saturation in most soils are limiting factors for plant growth. Application of P fertilizers and liming coupled with efficient placement can be recommended to enhance P availability and

  2. Methanotrophic activity and diversity of methanotrophs in volcanic-geothermal soils at Pantelleria island (Italy)

    OpenAIRE

    A. L. Gagliano; W. D'Alessandro; M. Tagliavia; Parello, F.; Quatrini, P.

    2014-01-01

    Volcanic and geothermal systems emit endogenous gases by widespread degassing from soils, including CH4, a greenhouse gas twenty-five times as potent as CO2. Recently, it has been demonstrated that volcanic or geothermal soils are not only a source of methane, but are also sites of methanotrophic activity. Methanotrophs are able to consume 10–40 Tg of CH4 a−1 and to trap more than 50% of the methane degassing through the soils. We report on methane microbial oxidation in the...

  3. Characterization, functioning and classification of two volcanic soil profiles under different land uses in Central Mexico

    OpenAIRE

    Prado, B.; Duwig, Céline; Hidalgo, C; Gomez, D.; Yee, H.; Prat, Christian; Esteves, Michel; Etchevers, J.D.

    2007-01-01

    Volcanic soils constitute an important resource for agriculture and forestry in Central Mexico, as well as in various world regions. They exhibit unique properties and high productive potential related to the amorphous materials they contain. The relationship between amorphous materials, soil characteristic and functioning, has not been well studied. The objectives of the present work were to assess the influence of land use (agricultural and forest), topography and other soil forming factors...

  4. Soil radon pulses related to the initial phase of volcanic eruptions

    Energy Technology Data Exchange (ETDEWEB)

    Segovia, N. [Instituto Nacional de Investigaciones Nucleares, Mexico City (Mexico); Mena, M. [IGFUNAM, Mexico City (Mexico)

    1999-08-01

    Soil radon behaviour related to the initial phase of volcanic eruptions is analysed from reported values related to the explosiveness of four American stratovolcaneos: El Chicon (1982) and Popocatepetl (1994) in Mexico, Poas (1987-1990) in Costa Rica and Cerro Negro (1982) in Nicaragua. The measurements in the field were performed with solid-state nuclear track detectors and electrets. The ratio between the magnitudes of the radon in soil peaks generated when the eruptive period started and the average radon values corresponding to quiescence periods indicate a dependence on the volcanic eruptive index for each one of the eruptive periods.

  5. Paleomagnetic Results of th Red Soil Volcanic Rock Series of Yingfengling Section,Southern Leizhou Peninsula

    Institute of Scientific and Technical Information of China (English)

    王俊达; 梁池生

    2002-01-01

    The Yingfengling scetion composed of red soil and volcanic rocks can be distinguished into 8 stratigraphic units and 4 red soil-volcanic rock cycles.64 paleomagnetic-orientated samples were collected from the bottom to the top of the section.Naturel remanent magnetization and magnetic susceptibility were firstly measured.All the samples were stepwisely treated with thermal or/and alternating fields.Four clear polarity segments were recorded in the section.Compared with the geo-magnetc polarity scale,the section was formed since the late Olduvai subchron,about 1.37Ma.B.P.

  6. Bioavailability and cellular effects of metals on Lumbricus terrestris inhabiting volcanic soils

    Energy Technology Data Exchange (ETDEWEB)

    Amaral, Andre [Departamento de Biologia, Universidade dos Acores, R. Mae de Deus, APT 1422, PT-9501-855 Ponta Delgada (Portugal)]. E-mail: aamaral@notes.uac.pt; Soto, Manu [Biologia Zelularra eta Histologia Laborategia, Zoologia eta Biologia Zelularra Saila, Zientzi Fakultatea, Euskal Herriko Unibertsitatea, 644 PK E-48080 Bilbao (Spain); Cunha, Regina [Departamento de Biologia, Universidade dos Acores, R. Mae de Deus, APT 1422, PT-9501-855 Ponta Delgada (Portugal); Marigomez, Ionan [Biologia Zelularra eta Histologia Laborategia, Zoologia eta Biologia Zelularra Saila, Zientzi Fakultatea, Euskal Herriko Unibertsitatea, 644 PK E-48080 Bilbao (Spain); Rodrigues, Armindo [Departamento de Biologia, Universidade dos Acores, R. Mae de Deus, APT 1422, PT-9501-855 Ponta Delgada (Portugal)

    2006-07-15

    Whether the radial thickness (RT) of the chloragogenous tissue and intestinal epithelium of earthworms (Lumbricus terrestris) reflects the bioavailability of metals in soils was investigated in two areas, one with active volcanism (Furnas) and another with no volcanic activity since 3 million years ago (Santa Maria), in the Azores. Metal contents in soil samples and earthworms from the two areas were analyzed. Autometallography and measurements of the RT were performed in the chloragogenous tissue and intestinal epithelium. Earthworms from the active volcanic area demonstrated lower RT of chloragogenous tissue and intestinal epithelium as well as higher levels of bioavailable metals, especially Zn and Cd. Comparison of bioavailable metal contents between both areas suggests a higher risk for uptake of potentially toxic metals in the active volcanic area than in the non-active volcanic area, which is reflected by the lower RT of the chloragogenous tissue and intestinal epithelium in the former. - In earthworms, differences in the chloragogenous tissue morphometry may be related to the bioavailability of metals in soils.

  7. Selective Extraction Methods for Aluminium, Iron and Organic Carbon from Montane Volcanic Ash Soils

    Institute of Scientific and Technical Information of China (English)

    B. JANSEN; F. H. TONNEIJCK; J. M. VERSTRATEN

    2011-01-01

    Montane volcanic ash soils contain disproportionate amounts of soil organic carbon and thereby play an often underestimated role in the global carbon cycle.Given the central role of A1 and Fe in stabilizing organic matter in volcanic ash soils,we assessed various extraction methods of A1,Fe,and C fractions from montane volcanic ash soils in northern Ecuador,aiming at elucidating the role of A1 and Fe in stabilizing soil organic matter (SOM).We found extractions with cold sodium hydroxide,ammonium oxalate/oxalic acid,sodium pyrophosphate,and sodium tetraborate to be particularly useful.Combination of these methods yielded information about the role of the mineral phase in stabilizing organic matter and the differences in type and degree of complexation of organic matter with Al and Fe in the various horizons and soil profiles.Sodium tetraborate extraction proved the only soft extraction method that yielded simultaneous information about the Al,Fe,and C fractions extracted.It also appeared to differentiate between SOM fractions of different stability.The fractions of copper chloride- and potassium chloride-extractable A1 were useful in assessing the total reactive and toxic Al fractions,respectively.The classical subdivision of organic matter into humic acids,fulvic acids,and humin added little useful information.The use of fulvic acids as a proxy for mobile organic matter as done in several model-based approaches seems invalid in the soils studied.

  8. The use of volcanic soil as mineral landfill liner--I. Physicochemical characterization and comparison with zeolites.

    Science.gov (United States)

    Navia, Rodrigo; Hafner, Georg; Raber, Georg; Lorber, Karl E; Schöffmann, Elke; Vortisch, Walter

    2005-06-01

    The main physicochemical characteristics of the volcanic soil of Southern Chile, with allophane as the main pedogenic mineral phase were analysed and compared with common zeolites (clinoptilolite) of the European market. The ultimate goal of this study was to test volcanic soil for the use as mineral landfill liner. The main results indicated that the clay and silt fractions together of the volcanic soil were between 38 and 54%. The buffering capacity of the volcanic soil was higher compared with the studied zeolites, whereas the cationic exchange capacity of the volcanic soil (between 5.2 and 6.5 cmol + kg(-1)) is of the same order of magnitude of the studied zeolites (between 9.7 and 11.4 cmol + kg(-1)). Moreover, the anionic exchange capacity of the volcanic soil was higher compared to the zeolites analysed. The hydraulic conductivity of the volcanic soil, measured in the laboratory at maximum proctor density, ranges between 5.16 x 10(-9) and 6.48 x 10(-9) m s(-1), a range that is comparable to the value of 4.51 x 10(-9) m s(-1) of the studied zeolite. The Proctor densities of the volcanic soil are in a lower range (between 1.11 and 1.15 g ml(-1)) compared with zeolites (between 1.19 and 1.34 g ml(-1)). The volcanic soil physicochemical characteristics are comparable to all the requirements established in the Austrian landfill directive (DVO, 2000). Therefore, the use as mineral landfill basal sealing of the analysed volcanic soil appears reasonable, having a pollutant adsorption capacity comparable to zeolites. It is of special interest for Southern Chile, because there are no alternative mineral raw materials for basal liners of landfills. PMID:15988944

  9. Engineering Geological Properties of the Volcanic Rocks and Soils of the Canary Islands

    OpenAIRE

    González de Vallejo, Luis I.; Hijazo Ramiro, Teresa; Ferrer Gijón, Mercedes

    2008-01-01

    This paper analyses the engineering geological properties of the rocks and soils of the Canary Islands based on data from field studies, laboratory tests and extensive databases for volcanic materials. Geological properties and processes most relevant to geo-engineering are described. Geomechanical characterization of rock masses and soil deposits including rock mass classification, index and strength properties are presented. Some of the most relevant results show materials of low t...

  10. Enzyme activities and microbial indices of Mexican volcanic soils under different managements

    International Nuclear Information System (INIS)

    Soils at the Mexican Trans-volcanic Belt are extremely important because the lack of agricultural land in overpopulated areas in Mexico. In addition, contents of soil organic matter (SOM) have been declining since the Mexican fields have been cultivated intensively. The aim of this work was to study how different agricultural management practices affect the SOM quality, using biochemical and microbiological parameters as indices. (Author)

  11. Soil radon measurements as a potential tracer of tectonic and volcanic activity

    Science.gov (United States)

    Neri, Marco; Ferrera, Elisabetta; Giammanco, Salvatore; Currenti, Gilda; Cirrincione, Rosolino; Patanè, Giuseppe; Zanon, Vittorio

    2016-04-01

    In Earth Sciences there is a growing interest in studies concerning soil-radon activity, due to its potential as a tracer of numerous natural phenomena. Our work marks an advance in the comprehension of the interplay between tectonic activity, volcanic eruptions and gas release through faults. Soil-radon measurements, acquired on Mt. Etna volcano in 2009–2011, were analyzed. Our radon probe is sensitive to changes in both volcanic and seismic activity. Radon data were reviewed in light of the meteorological parameters. Soil samples were analyzed to characterize their uranium content. All data have been summarized in a physical model which identifies the radon sources, highlights the mechanism of radon transport and envisages how such a mechanism may change as a consequence of seismicity and volcanic events. In the NE of Etna, radon is released mainly from a depth of 50 m/day. Three periods of anomalous gas release were found (February 2010, January and February 2011). The trigger of the first anomaly was tectonic, while the second and third had a volcanic origin. These results mark a significant step towards a better understanding of the endogenous mechanisms that cause changes in soil-radon emission at active volcanoes.

  12. Soil radon measurements as a potential tracer of tectonic and volcanic activity.

    Science.gov (United States)

    Neri, Marco; Ferrera, Elisabetta; Giammanco, Salvatore; Currenti, Gilda; Cirrincione, Rosolino; Patanè, Giuseppe; Zanon, Vittorio

    2016-04-15

    In Earth Sciences there is a growing interest in studies concerning soil-radon activity, due to its potential as a tracer of numerous natural phenomena. Our work marks an advance in the comprehension of the interplay between tectonic activity, volcanic eruptions and gas release through faults. Soil-radon measurements, acquired on Mt. Etna volcano in 2009-2011, were analyzed. Our radon probe is sensitive to changes in both volcanic and seismic activity. Radon data were reviewed in light of the meteorological parameters. Soil samples were analyzed to characterize their uranium content. All data have been summarized in a physical model which identifies the radon sources, highlights the mechanism of radon transport and envisages how such a mechanism may change as a consequence of seismicity and volcanic events. In the NE of Etna, radon is released mainly from a depth of 50 m/day. Three periods of anomalous gas release were found (February 2010, January and February 2011). The trigger of the first anomaly was tectonic, while the second and third had a volcanic origin. These results mark a significant step towards a better understanding of the endogenous mechanisms that cause changes in soil-radon emission at active volcanoes.

  13. Landscape formation and soil genesis in volcanic parent materials in humid tropical lowlands of Costa Rica.

    OpenAIRE

    Van NIEUWENHUYSE, A.

    1996-01-01

    The influence of volcanism on landscape genesis, and formation of soils on volcanic parent material was studied in the Atlantic lowland of Costs Rica. This lowland is a subduction basin of tectonic origin, in which thick alluvial and marine sediments are accumulated. At its southwestern side it is bordered by active volcanoes. The climate of the area is hot and humid throughout the year, with a constant mean air temperature of about 25°C and a welldistributed mean annual rainfall of about 350...

  14. Radiocaesium fallout behaviour in volcanic soils in Iceland.

    Science.gov (United States)

    Sigurgeirsson, M A; Arnalds, O; Palsson, S E; Howard, B J; Gudnason, K

    2005-01-01

    The retention of 137Cs in various types of Andosols in Iceland was investigated. Soils were sampled at 29 sites with varying precipitation and environmental conditions. Samples were obtained from 0 to 5, 5 to 10, and 10 to 15 cm depths. The amount of radiocaesium present was quite variable, ranging between 300 and 4800 Bq m(-2) and correlated closely to total annual precipitation (r2=0.71). The majority of 137Cs, 82.7% on average, was retained in the uppermost 5 cm of the soil. The greatest penetration of 137Cs was observed for organic Histosols (76.3% in top 5 cm). The Icelandic Vitrisols (barren, poorly developed Andosols) are coarse grained with only 2-5% clay content and contain little organic matter (soils retained 74% of 137Cs in the top 5 cm. The results indicate that radiocaesium fallout is strongly retained by colloidal materials characteristic of Andosols, such as allophane and ferrihydrite. Most soils in Iceland are subject to severe and prolonged freezing and waterlogging; despite this, 137Cs is retained in the upper soil horizons and vertical migration is negligible in Icelandic Andosols. However, erosion and aeolian activity can markedly influence the amount and vertical distribution of radiocaesium in Icelandic soils. PMID:15571875

  15. Radiocaesium fallout behaviour in volcanic soils in Iceland

    Energy Technology Data Exchange (ETDEWEB)

    Sigurgeirsson, M.A. [Icelandic Radiation Protection Institute, Raudararstigur 10, IS-150 Reykjavik (Iceland)]. E-mail: ms@gr.is; Arnalds, O. [Agricultural Research Institute, Keldnaholt, IS-112 Reykjavik (Iceland); Palsson, S.E. [Icelandic Radiation Protection Institute, Raudararstigur 10, IS-150 Reykjavik (Iceland); Howard, B.J. [Centre for Ecology and Hydrology, Library Avenue, Bailrigg, Lancaster LA1 4AP (United Kingdom); Gudnason, K. [Icelandic Radiation Protection Institute, Raudararstigur 10, IS-150 Reykjavik (Iceland)

    2005-07-01

    The retention of {sup 137}Cs in various types of Andosols in Iceland was investigated. Soils were sampled at 29 sites with varying precipitation and environmental conditions. Samples were obtained from 0 to 5, 5 to 10, and 10 to 15 cm depths. The amount of radiocaesium present was quite variable, ranging between 300 and 4800 Bq m{sup -2} and correlated closely to total annual precipitation (r{sup 2} = 0.71). The majority of {sup 137}Cs, 82.7% on average, was retained in the uppermost 5 cm of the soil. The greatest penetration of {sup 137}Cs was observed for organic Histosols (76.3% in top 5 cm). The Icelandic Vitrisols (barren, poorly developed Andosols) are coarse grained with only 2-5% clay content and contain little organic matter (<1%). Yet these soils retained 74% of {sup 137}Cs in the top 5 cm. The results indicate that radiocaesium fallout is strongly retained by colloidal materials characteristic of Andosols, such as allophane and ferrihydrite. Most soils in Iceland are subject to severe and prolonged freezing and waterlogging; despite this, {sup 137}Cs is retained in the upper soil horizons and vertical migration is negligible in Icelandic Andosols. However, erosion and aeolian activity can markedly influence the amount and vertical distribution of radiocaesium in Icelandic soils.

  16. Radiocaesium fallout behaviour in volcanic soils in Iceland

    International Nuclear Information System (INIS)

    The retention of 137Cs in various types of Andosols in Iceland was investigated. Soils were sampled at 29 sites with varying precipitation and environmental conditions. Samples were obtained from 0 to 5, 5 to 10, and 10 to 15 cm depths. The amount of radiocaesium present was quite variable, ranging between 300 and 4800 Bq m-2 and correlated closely to total annual precipitation (r2 = 0.71). The majority of 137Cs, 82.7% on average, was retained in the uppermost 5 cm of the soil. The greatest penetration of 137Cs was observed for organic Histosols (76.3% in top 5 cm). The Icelandic Vitrisols (barren, poorly developed Andosols) are coarse grained with only 2-5% clay content and contain little organic matter (137Cs in the top 5 cm. The results indicate that radiocaesium fallout is strongly retained by colloidal materials characteristic of Andosols, such as allophane and ferrihydrite. Most soils in Iceland are subject to severe and prolonged freezing and waterlogging; despite this, 137Cs is retained in the upper soil horizons and vertical migration is negligible in Icelandic Andosols. However, erosion and aeolian activity can markedly influence the amount and vertical distribution of radiocaesium in Icelandic soils

  17. Radiocaesium fallout behaviour in volcanic soils in Iceland

    Energy Technology Data Exchange (ETDEWEB)

    Sigurgeirsson, M.A.; Arnalds, O.; Palsson, S.E.; Gudnason, K. [Icelandic Radiation Protection Institute, Division of Environmental Monitoring and Emergency Preparedness, Reykjavik (Iceland)

    2004-07-01

    In 2000-2002 the retention of {sup 137}Cs in various types of andosols, which are the most abundant soils in Iceland, was investigated. This is the first comprehensive attempt to determine radiocaesium levels and retention characteristics of Icelandic soils. Soils were sampled at 29 sites located near meteorological stations covering variation in precipitation and environmental conditions. Samples were obtained from 0- 5, 5-10, and 10-15 cm depths. Several physical and chemical parameters were measured, such as organic carbon, cation exchange capacity, pH and clay mineral content. The radiocaesium activity is quite variable and ranges between 300 and 4800 Bq/m{sup 2} and correlates closely to total annual precipitation (r{sup 2}=0.9). Most of the radiocaesium is retained in the uppermost 5 cm of the soil, or 83% on average. The greatest penetration was observed for organic Histo-sols, where 6% of the total {sup 137}Cs was found at 10-15 cm depth compared to less than 3% for Andosols types. The Icelandic Vitrisols (barren, poorly developed Andosols) are coarse grained with low clay content and contain little organic matter (<1%). Yet these soils retained 74% of {sup 137}Cs in the top 5 cm in our study. The results clearly indicate that radioactive fallout caesium is strongly retained by colloidal materials characteristic of Andosols, such as allophane and ferri-hydrite. Winter frost, snow melt, crack flow, and animal activity seem to have little effect on the {sup 137}Cs distribution at the present sampling sites. However, erosion and aeolian activity can markedly influence the aerial activity and vertical distribution of radiocaesium in Icelandic soils. (author)

  18. Radiocaesium fallout behaviour in volcanic soils in Iceland

    International Nuclear Information System (INIS)

    In 2000-2002 the retention of 137Cs in various types of andosols, which are the most abundant soils in Iceland, was investigated. This is the first comprehensive attempt to determine radiocaesium levels and retention characteristics of Icelandic soils. Soils were sampled at 29 sites located near meteorological stations covering variation in precipitation and environmental conditions. Samples were obtained from 0- 5, 5-10, and 10-15 cm depths. Several physical and chemical parameters were measured, such as organic carbon, cation exchange capacity, pH and clay mineral content. The radiocaesium activity is quite variable and ranges between 300 and 4800 Bq/m2 and correlates closely to total annual precipitation (r2=0.9). Most of the radiocaesium is retained in the uppermost 5 cm of the soil, or 83% on average. The greatest penetration was observed for organic Histo-sols, where 6% of the total 137Cs was found at 10-15 cm depth compared to less than 3% for Andosols types. The Icelandic Vitrisols (barren, poorly developed Andosols) are coarse grained with low clay content and contain little organic matter (137Cs in the top 5 cm in our study. The results clearly indicate that radioactive fallout caesium is strongly retained by colloidal materials characteristic of Andosols, such as allophane and ferri-hydrite. Winter frost, snow melt, crack flow, and animal activity seem to have little effect on the 137Cs distribution at the present sampling sites. However, erosion and aeolian activity can markedly influence the aerial activity and vertical distribution of radiocaesium in Icelandic soils. (author)

  19. Selenium mobilization in soils due to volcanic derived acid-rain: an example from Mt Etna volcano, Sicily

    OpenAIRE

    Floor, G; S. Calabrese; Roman-Ross, G; D´Alessandro, W; Aiuppa, A.

    2011-01-01

    The significant amounts of selenium(Se)emitted by volcanoesmay have important impact on human health due to the narrow range between nutrition requirement and toxic effects for living organisms upon Se exposure. Although soils play a key role in determining the level in food and water and thereby human health, little is known about the behaviour of Se in volcanic soils. In this work we evaluated the Se release during rainwater–soil interaction under controlled conditions using soils collected...

  20. Methanotrophic activity and bacterial diversity in volcanic-geothermal soils at Pantelleria island (Italy)

    Science.gov (United States)

    Gagliano, A. L.; D'Alessandro, W.; Tagliavia, M.; Parello, F.; Quatrini, P.

    2014-04-01

    Volcanic and geothermal systems emit endogenous gases by widespread degassing from soils, including CH4, a greenhouse gas twenty-five times as potent as CO2. Recently, it has been demonstrated that volcanic/geothermal soils are source of methane, but also sites of methanotrophic activity. Methanotrophs are able to consume 10-40 Tg of CH4 a-1 and to trap more than 50% of the methane degassing through the soils. We report on methane microbial oxidation in the geothermally most active site of Pantelleria island (Italy), Favara Grande, whose total methane emission was previously estimated in about 2.5 t a-1. Laboratory incubation experiments with three top-soil samples from Favara Grande indicated methane consumption values up to 950 ng g-1 dry soil h-1. One of the three sites, FAV2, where the highest oxidation rate was detected, was further analysed on a vertical soil profile and the maximum methane consumption was measured in the top-soil layer but values > 100 ng g-1 h-1 were maintained up to a depth of 15 cm. The highest consumption rate was measured at 37 °C, but a still recognizable consumption at 80 °C (> 20 ng g-1 h-1) was recorded. In order to estimate the bacterial diversity, total soil DNA was extracted from Favara Grande and analysed using a Temporal Temperature Gradient gel Electrophoresis (TTGE) analysis of the amplified bacterial 16S rRNA gene. The three soil samples were probed by PCR using standard proteobacterial primers and newly designed verrucomicrobial primers targeting the unique methane monooxygenase gene pmoA; the presence of methanotrophs was detected in sites FAV2 and FAV3, but not in FAV1, where harsher chemical-physical conditions and negligible methane oxidation were detected. The pmoA gene libraries from the most active site FAV2 pointed out a high diversity of gammaproteobacterial methanotrophs distantly related to Methylococcus/Methylothermus genera and the presence of the newly discovered acido-thermophilic methanotrophs

  1. A preliminary evaluation of volcanic rock powder for application in agriculture as soil a remineralizer

    International Nuclear Information System (INIS)

    Mineralogical and geochemical characteristics of volcanic rock residue, from a crushing plant in the Nova Prata Mining District, State of Rio Grande do Sul (RS), Brazil, in this work named rock powder, were investigated in view of its potential application as soil ammendment in agriculture. Abaut 52,400 m3 of mining waste is generated annually in the city of Nova Prata without a proper disposal. The nutrients potentially available to plants were evaluated through leaching laboratory tests. Nutrient leaching tests were performed in Milli-Q water; citric acid solution 1% and 2% (AC); and oxalic acid solution 1% and 5% (AO). The bulk and leachable contents of 57 elements were determined by inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma atomic emission spectroscopy (ICP-AES). Mining waste were made up by CaO, K2O, SiO2, Al2O3, Fe2O3, and P2O5. The analysis by X-ray diffraction (XRD) showed the major occurence of quartz, anorthite, cristobalite, sanidine, and augite. The water leachable concentrations of all elements studied were lower than 1.0 mg/kg, indicating their low solubility. Leaching tests in acidic media yield larger leachable fractions for all elements being studied are in the leachate of the AO 1%. These date usefulness of volcanic rock powder as potential natural fertilizer in agriculture in the mining district in Nova Prata, Rio Grande do Sul, Brazil to reduce the use of chemical fertilizers. - Highlights: • Volcanic rock powder as fertilizer in agriculture • Volcanic rock powder as a source of nutrients to plants • This technology may favor the use of volcanic rock in agriculture

  2. A preliminary evaluation of volcanic rock powder for application in agriculture as soil a remineralizer

    Energy Technology Data Exchange (ETDEWEB)

    Ramos, Claudete G., E-mail: claudeterms@brturbo.com.br [Laboratory of Environmental Researches and Nanotechnology Development, Centro Universitário La Salle, Mestrado em Avaliação de Impactos Ambientais, Victor Barreto, 2288 Centro, 92010-000 Canoas, RS (Brazil); Querol, Xavier [Institute of Environmental Assessment and Water Research (IDÆA-CSIC), C/Luis Solé y Sabarís s/n, 08028 Barcelona (Spain); Oliveira, Marcos L.S. [Laboratory of Environmental Researches and Nanotechnology Development, Centro Universitário La Salle, Mestrado em Avaliação de Impactos Ambientais, Victor Barreto, 2288 Centro, 92010-000 Canoas, RS (Brazil); Pires, Karen [Departamento Nacional de Produção Mineral (DNPM), Washington Luiz, 815, Centro, 90010-460 Porto Alegre, RS (Brazil); Kautzmann, Rubens M. [Laboratory of Environmental Researches and Nanotechnology Development, Centro Universitário La Salle, Mestrado em Avaliação de Impactos Ambientais, Victor Barreto, 2288 Centro, 92010-000 Canoas, RS (Brazil); Oliveira, Luis F.S., E-mail: felipeqma@hotmail.com [Laboratory of Environmental Researches and Nanotechnology Development, Centro Universitário La Salle, Mestrado em Avaliação de Impactos Ambientais, Victor Barreto, 2288 Centro, 92010-000 Canoas, RS (Brazil)

    2015-04-15

    Mineralogical and geochemical characteristics of volcanic rock residue, from a crushing plant in the Nova Prata Mining District, State of Rio Grande do Sul (RS), Brazil, in this work named rock powder, were investigated in view of its potential application as soil ammendment in agriculture. Abaut 52,400 m{sup 3} of mining waste is generated annually in the city of Nova Prata without a proper disposal. The nutrients potentially available to plants were evaluated through leaching laboratory tests. Nutrient leaching tests were performed in Milli-Q water; citric acid solution 1% and 2% (AC); and oxalic acid solution 1% and 5% (AO). The bulk and leachable contents of 57 elements were determined by inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma atomic emission spectroscopy (ICP-AES). Mining waste were made up by CaO, K{sub 2}O, SiO{sub 2}, Al{sub 2}O{sub 3}, Fe{sub 2}O{sub 3}, and P{sub 2}O{sub 5}. The analysis by X-ray diffraction (XRD) showed the major occurence of quartz, anorthite, cristobalite, sanidine, and augite. The water leachable concentrations of all elements studied were lower than 1.0 mg/kg, indicating their low solubility. Leaching tests in acidic media yield larger leachable fractions for all elements being studied are in the leachate of the AO 1%. These date usefulness of volcanic rock powder as potential natural fertilizer in agriculture in the mining district in Nova Prata, Rio Grande do Sul, Brazil to reduce the use of chemical fertilizers. - Highlights: • Volcanic rock powder as fertilizer in agriculture • Volcanic rock powder as a source of nutrients to plants • This technology may favor the use of volcanic rock in agriculture.

  3. Organic matter protection as affected by the mineral soil matrix: allophanic vs. non-allophanic volcanic ash soils

    Science.gov (United States)

    Nierop, K. G. J.; Kaal, J.; Jansen, B.; Naafs, D. F. W.

    2009-04-01

    Volcanic ash soils (Andosols) contain the largest amounts of organic carbon of all mineral soil types. Chemical (complexes of organic matter with allophane, Al/Fe) and physical (aggregation) mechanisms are protecting the carbon from decomposition. While allophanic Andosols are dominated by short range order minerals such as allophane, imogolite and ferrihydrite, organic matter-Al/Fe complexes dominate non-allophanic Andosols. Consequently, chemical interactions between the mineral soil matrix and organic matter differ between these two soil types. This difference could potentially lead to different organic matter compositions. In this study, the organic matter of Ah horizons of an allophanic Andosol with a non-allophanic Andosol from Madeira Island is compared using analytical pyrolysis. Both volcanic soil types showed a relative decrease of lignin-derived pyrolysis products with depth, but this decrease was more pronounced in the allophanic Andosol. Polysaccharides were more abundant in the allophanic Ah horizon, particularly at lower depth, and this was also the case for the non-plant-derived N-containing polysaccharide chitin. Most likely, these biopolymers are adsorbed onto short range order minerals such as allophane and therefore were better protected in the allophanic Andosol. In addition, the higher chitin contents combined with the more pronounced lignin degradation suggests a higher fungal activity. Aliphatic pyrolysis products (n-alkenes/n-alkanes, fatty acids) were relatively more enriched in the non-allophanic Andosol. Lower microbial activity caused by the more acidic pH and higher levels of (toxic) aluminium are the most plausible reasons for the accumulation of these compounds in the non-allophanic Andosol. Although the allophanic and non-allophanic Andosol resembled each other in containing biopolymer groups of the same orders of magnitudes, in particular the contents of chitin and aliphatic compounds were distinctly affected by the differences in

  4. Methanotrophic activity and diversity of methanotrophs in volcanic geothermal soils at Pantelleria (Italy)

    Science.gov (United States)

    Gagliano, A. L.; D'Alessandro, W.; Tagliavia, M.; Parello, F.; Quatrini, P.

    2014-10-01

    Volcanic and geothermal systems emit endogenous gases by widespread degassing from soils, including CH4, a greenhouse gas twenty-five times as potent as CO2. Recently, it has been demonstrated that volcanic or geothermal soils are not only a source of methane, but are also sites of methanotrophic activity. Methanotrophs are able to consume 10-40 Tg of CH4 a-1 and to trap more than 50% of the methane degassing through the soils. We report on methane microbial oxidation in the geothermally most active site of Pantelleria (Italy), Favara Grande, whose total methane emission was previously estimated at about 2.5 Mg a-1 (t a-1). Laboratory incubation experiments with three top-soil samples from Favara Grande indicated methane consumption values of up to 59.2 nmol g-1 soil d.w. h-1. One of the three sites, FAV2, where the highest oxidation rate was detected, was further analysed on a vertical soil profile, the maximum methane consumption was measured in the top-soil layer, and values greater than 6.23 nmol g-1 h-1 were still detected up to a depth of 13 cm. The highest consumption rate was measured at 37 °C, but a still detectable consumption at 80 °C (> 1.25 nmol g-1 h-1) was recorded. The soil total DNA extracted from the three samples was probed by Polymerase Chain Reaction (PCR) using standard proteobacterial primers and newly designed verrucomicrobial primers, targeting the unique methane monooxygenase gene pmoA; the presence of methanotrophs was detected at sites FAV2 and FAV3, but not at FAV1, where harsher chemical-physical conditions and negligible methane oxidation were detected. The pmoA gene libraries from the most active site (FAV2) pointed to a high diversity of gammaproteobacterial methanotrophs, distantly related to Methylocaldum-Metylococcus genera, and the presence of the newly discovered acido-thermophilic Verrucomicrobia methanotrophs. Alphaproteobacteria of the genus Methylocystis were isolated from enrichment cultures under a methane

  5. The Characteristic and Genesis of Volcanic Ash Soil in the North Slope Toposequence of Kawi Mountain in Malang Regency

    Directory of Open Access Journals (Sweden)

    A.N. Putra

    2015-07-01

    Full Text Available The volcanic ash soil in Kawi Mountain is composed by the amorphous materials consist of allophane, imogolite and ferrihydrite. Results of previous study showed that the phosphate retention in all soil profiles of northern slope toposequence of Kawimountain was less than 85%, yet the phosphate retention of volcanic ash soils is usually > 85 %. This raised a question that there is a different characteristics of soil in the northern slope tosequence of the Kawi Mountain compared to the other places. This research was conducted to study soil characteristics, mineral contents, and genesis processessoccuring in soil on the northern slope toposequence of Kawi Mountain. 5 pedons between high elevation and low elevation (P1, P2, P3, P4 and P5 to identified the soil characteristics. The Al, Fe, and Si extracted by acid oxalate, natrium pyrophosphate, and dithionite citrate to calculate the amorphous mineral content. The results show that. The results showed that there is a different in terms of the thickness of the A horizon, the C organic content and the soil acidity level that mainly found in P3 and P4 profiles. The most important soil genesis processess in the formation of the volcanic ash soils were likely clay illuviation (P5, melanization and braunification (P3, littering (P1 and the reduction of andic soil properties from the upper slope (P1 profile up to the lower slope (P5 profile.

  6. Influence of management practices on C stabilization pathways in agricultural volcanic ash soils (Canary Islands, Spain)

    Science.gov (United States)

    Hernandez, Zulimar; María Álvarez, Ana; Carral, Pilar; de Figueiredo, Tomas; Almendros, Gonzalo

    2014-05-01

    Although C stabilization mechanisms in agricultural soils are still controversial [1], a series of overlapped pathways has been suggested [2] such as: i) insolubilization of low molecular weight precursors of soil organic matter (SOM) with reactive minerals through physical and chemical bonding, ii) selective accumulation of biosynthetic substances which are recalcitrant because of its inherent chemical composition, and iii) preservation and furter diagenetic transformation of particulate SOM entrapped within resistant microaggregates, where diffusion of soil enzymes is largely hampered. In some environments where carbohydrate and N compounds are not readily biodegraded, e.g., with water saturated micropores, an ill-known C stabilization pathway may involve the formation of Maillard's reaction products [3]. In all cases, these pathways converge in the formation of recalcitrant macromolecular substances, sharing several properties with the humic acid (HA) fraction [4]. In template forests, the selective preservation and further microbial reworking of plant biomass has been identified as a prevailing mechanism in the accumulation of recalcitrant SOM forms [5]. However, in volcanic ash soils with intense organomineral interactions, condensation reactions of low molecular weight precursors with short-range minerals may be the main mechanism [6]. In order to shed some light about the effect of agricultural management on soil C stabilization processes on volcanic ash soils, the chemical composition of HA and some structural proxies of SOM informing on its origin and potential resistance to biodegradation, were examined in 30 soils from Canary Islands (Spain) by visible, infrared (IR) and 13C nuclear magnetic resonance (NMR) spectroscopies, elementary analysis and pyrolytic techniques. The results of multivariate treatments, suggested at least three simultaneous C stabilization biogeochemical trends: i) diagenetic alteration of plant biomacromolecules in soils receiving

  7. Linking trace metals and agricultural land use in volcanic soils--a multivariate approach.

    Science.gov (United States)

    Parelho, C; Rodrigues, A S; Cruz, J V; Garcia, P

    2014-10-15

    The concern about the environmental impacts caused by agriculture intensification is growing as large amounts of nutrients and contaminants are introduced into soil ecosystems. Volcanic soils are unique naturally fertile resources extensively used for agricultural purposes, with particular physical and chemical properties that may result in possible accumulation of toxic substances, such as metals. Within this particular geological context, the present study aims to evaluate the impact of different agricultural systems (conventional, traditional and organic) in trace metal (TM) soil pollution and define the tracers for each one. Physicochemical properties and TM contents in agricultural topsoils were determined. Enrichment Factors (EF) were calculated to distinguish geogenic and anthropogenic contribution to TM contents in agricultural soils. An ensemble of multivariate statistical analyses (PCA and FDA) was performed to reduce the multidimensional space of variables and samples, thus defining a set of TM as tracers of distinct agricultural farming systems. Results show that agricultural soils have low organic matter content (30%); in addition, electric conductivity in conventional farming soils is higher (262.3 ± 162.6 μS cm(-1)) while pH is lower (5.8 ± 0.3). Regarding metal inputs, V, Ba and Hg soil contents are mainly of geogenic origin, while Li, P, K, Cr, Mn, Ni, Cu, Zn, As, Mo, Cd and Pb result primarily from anthropogenic inputs. Li revealed to be a tracer of agricultural pollution in conventional farming soils, whereas V allowed the discrimination of traditional farming soils. This study points to agriculture as a diffuse source of anthropogenic TM soil pollution and is the first step to identify priority chemicals affecting agricultural Andosols. PMID:25093299

  8. Groundwater flow in a closed basin with a saline shallow lake in a volcanic area: Laguna Tuyajto, northern Chilean Altiplano of the Andes.

    Science.gov (United States)

    Herrera, Christian; Custodio, Emilio; Chong, Guillermo; Lambán, Luis Javier; Riquelme, Rodrigo; Wilke, Hans; Jódar, Jorge; Urrutia, Javier; Urqueta, Harry; Sarmiento, Alvaro; Gamboa, Carolina; Lictevout, Elisabeth

    2016-01-15

    Laguna Tuyajto is a small, shallow saline water lake in the Andean Altiplano of northern Chile. In the eastern side it is fed by springs that discharge groundwater of the nearby volcanic aquifers. The area is arid: rainfall does not exceed 200mm/year in the rainiest parts. The stable isotopic content of spring water shows that the recharge is originated mainly from winter rain, snow melt, and to a lesser extent from some short and intense sporadic rainfall events. Most of the spring water outflowing in the northern side of Laguna Tuyajto is recharged in the Tuyajto volcano. Most of the spring water in the eastern side and groundwater are recharged at higher elevations, in the rims of the nearby endorheic basins of Pampa Colorada and Pampa Las Tecas to the East. The presence of tritium in some deep wells in Pampa Colorada and Pampa Las Tecas indicates recent recharge. Gas emission in recent volcanoes increase the sulfate content of atmospheric deposition and this is reflected in local groundwater. The chemical composition and concentration of spring waters are the result of meteoric water evapo-concentration, water-rock interaction, and mainly the dissolution of old and buried evaporitic deposits. Groundwater flow is mostly shallow due to a low permeability ignimbrite layer of regional extent, which also hinders brine spreading below and around the lake. High deep temperatures near the recent Tuyajto volcano explain the high dissolved silica contents and the δ(18)O shift to heavier values found in some of the spring waters. Laguna Tuyajto is a terminal lake where salts cumulate, mostly halite, but some brine transfer to the Salar de Aguas Calientes-3 cannot be excluded. The hydrogeological behavior of Laguna Tuyajto constitutes a model to understand the functioning of many other similar basins in other areas in the Andean Altiplano.

  9. The Natural Terrestrial Carbon Sequestration Potential of Rocky Mountain Soils Derived From Volcanic Bedrock

    Science.gov (United States)

    Yager, D. B.; Burchell, A.; Johnson, R. H.

    2008-12-01

    The possible economic and environmental ramifications of climate change have stimulated a range of atmospheric carbon mitigation actions, as well as, studies to understand and quantify potential carbon sinks. However, current carbon management strategies for reducing atmospheric emissions underestimate a critical component. Soils represent between 18 - 30% of the terrestrial carbon sink needed to prevent atmospheric doubling of CO2 by 2050 and a crucial element in mitigating climate change, natural terrestrial sequestration (NTS), is required. NTS includes all naturally occurring, cumulative, biologic and geologic processes that either remove CO2 from the atmosphere or prevent net CO2 emissions through photosynthesis and microbial fixation, soil formation, weathering and adsorption or chemical reactions involving principally alumino- ferromagnesium minerals, volcanic glass and clays. Additionally, NTS supports ecosystem services by improving soil productivity, moisture retention, water purification and reducing erosion. Thus, 'global climate triage' must include the protection of high NTS areas, purposeful enhancement of NTS processes and reclamation of disturbed and mined lands. To better understand NTS, we analyzed soil-cores from Colorado, Rocky Mountain Cordillera sites. North-facing, high-plains to alpine sites in non-wetland environments were selected to represent temperate soils that may be less susceptible to carbon pool declines due to global warming than soils in warmer regions. Undisturbed soils sampled have 2 to 6 times greater total organic soil carbon (TOSC) than global TOSC averages (4 - 5 Wt. %). Forest soils derived from weathering of intermediate to mafic volcanic bedrock have the highest C (34.15 Wt. %), C:N (43) and arylsulfatase (ave. 278, high 461 μg p-nitrophenol/g/h). Intermediate TOSC was identified in soils derived from Cretaceous shale (7.2 Wt. %) and Precambrian, felsic gneiss (6.2 Wt. %). Unreclaimed mine-sites have the lowest C (0

  10. Methanotrophic activity and bacterial diversity in volcanic-geothermal soils at Pantelleria island (Italy

    Directory of Open Access Journals (Sweden)

    A. L. Gagliano

    2014-04-01

    Full Text Available Volcanic and geothermal systems emit endogenous gases by widespread degassing from soils, including CH4, a greenhouse gas twenty-five times as potent as CO2. Recently, it has been demonstrated that volcanic/geothermal soils are source of methane, but also sites of methanotrophic activity. Methanotrophs are able to consume 10–40 Tg of CH4 a−1 and to trap more than 50% of the methane degassing through the soils. We report on methane microbial oxidation in the geothermally most active site of Pantelleria island (Italy, Favara Grande, whose total methane emission was previously estimated in about 2.5 t a−1. Laboratory incubation experiments with three top-soil samples from Favara Grande indicated methane consumption values up to 950 ng g−1 dry soil h−1. One of the three sites, FAV2, where the highest oxidation rate was detected, was further analysed on a vertical soil profile and the maximum methane consumption was measured in the top-soil layer but values > 100 ng g−1 h−1 were maintained up to a depth of 15 cm. The highest consumption rate was measured at 37 °C, but a still recognizable consumption at 80 °C (> 20 ng g−1 h−1 was recorded. In order to estimate the bacterial diversity, total soil DNA was extracted from Favara Grande and analysed using a Temporal Temperature Gradient gel Electrophoresis (TTGE analysis of the amplified bacterial 16S rRNA gene. The three soil samples were probed by PCR using standard proteobacterial primers and newly designed verrucomicrobial primers targeting the unique methane monooxygenase gene pmoA; the presence of methanotrophs was detected in sites FAV2 and FAV3, but not in FAV1, where harsher chemical-physical conditions and negligible methane oxidation were detected. The pmoA gene libraries from the most active site FAV2 pointed out a high diversity of gammaproteobacterial methanotrophs distantly related to Methylococcus/Methylothermus genera and the presence of the newly discovered acido

  11. [Chilean nuclear policy].

    Science.gov (United States)

    Bobadilla, E

    1996-06-01

    This official document is statement of the President of the Chilean Nuclear Energy Commission, Dr. Eduardo Bobadilla, about the nuclear policy of the Chilean State, Thanks to the international policy adopted by presidents Aylwin (1990-1994) and his successor Frei Ruiz Tagle (1994-), a nuclear development plan, protected by the Chilean entrance to the nuclear weapons non proliferation treaty and Tlatelolco Denuclearization treaty, has started. Chile will be able to develop without interference, an autonomous nuclear electrical system and other pacific uses of nuclear energy. Chile also supports a new international treaty to ban nuclear weapon tests.

  12. [Chilean nuclear policy].

    Science.gov (United States)

    Bobadilla, E

    1996-06-01

    This official document is statement of the President of the Chilean Nuclear Energy Commission, Dr. Eduardo Bobadilla, about the nuclear policy of the Chilean State, Thanks to the international policy adopted by presidents Aylwin (1990-1994) and his successor Frei Ruiz Tagle (1994-), a nuclear development plan, protected by the Chilean entrance to the nuclear weapons non proliferation treaty and Tlatelolco Denuclearization treaty, has started. Chile will be able to develop without interference, an autonomous nuclear electrical system and other pacific uses of nuclear energy. Chile also supports a new international treaty to ban nuclear weapon tests. PMID:9041734

  13. Estimation of the soil strength parameters in Tertiary volcanic regolith (NE Turkey) using analytical hierarchy process

    Indian Academy of Sciences (India)

    Hakan Ersoy; Melek Betül Karsli; Seda Çellek; Bilgehan Kul; Idris Baykan; Robert L Parsons

    2013-12-01

    Costly and time consuming testing techniques and the difficulties in providing undisturbed samples for these tests have led researchers to estimate strength parameters of soils with simple index tests. However, the paper focuses on estimation of strength parameters of soils as a function of the index properties. Analytical hierarchy process and multiple regression analysis based methodology were performed on datasets obtained from soil tests on 41 samples in Tertiary volcanic regolith. While the hierarchy model focused on determining the most important index properties affecting on strength parameters, regression analysis established meaningful relationships between strength parameters and index properties. The negative polynomial correlations between the friction angle and plasticity properties, and the positive exponential relations between the cohesion and plasticity properties were determined. These relations are characterized by a regression coefficient of 0.80. However, Terzaghi bearing capacity formulas were used to test the model. It is important to see whether there is any statistically significant relation between the calculated and the observed bearing capacity values for model testing. Based on the model, the positive linear correlation characterized by the regression coefficient of 0.86 were determined between bearing capacity values obtained by direct and indirect methods.

  14. Soil gas measurements around the most recent volcanic system of metropolitan France (Lake Pavin, Massif Central)

    International Nuclear Information System (INIS)

    Soil gas monitoring techniques (CO2, O2, 222Rn, 4He) are used in the geographical context of the recent volcanic system of Lake Pavin (Puy-de-Dome), to get a better knowledge of local gaseous emissions, in order to establish whether or not this system can present evidence of reactivation. Concentrations up to 100% CO2 and 50 ppm of helium are measured in a narrow geographical area (Escarot Mofette), together with a magmatic origin for these gases. Radon activity in the Mofette area is quite high, but does not show, compared to surrounding areas, enrichments as high as those measured for CO2 or helium. Hourly records of these radon activities, performed during several weeks, suggest the existence of pulsed radon exhalation in the Mofette area. The period of this pulsation is around 40 days but its origin remains poorly understood. Apart from this Mofette, no evidence of gas originating from depth is highlighted. (authors)

  15. Evaluation of rainfall infiltration characteristics in a volcanic ash soil by time domain reflectometry method

    Directory of Open Access Journals (Sweden)

    S. Hasegawa

    1997-01-01

    Full Text Available Time domain reflectometry (TDR was used to monitor soil water conditions and to evaluate infiltration characteristics associated with rainfall into a volcanic-ash soil (Hydric Hapludand with a low bulk density. Four 1 m TDR probes were installed vertically along a 6 m line in a bare field. Three 30 cm and one 60 cm probes were installed between the 1 m probes. Soil water content was measured every half or every hour throughout the year. TDR enabled prediction of the soil water content precisely even though the empirical equation developed by Topp et al. (1980 underestimated the water content. Field capacity, defined as the amount of water stored to a depth of 1 m on the day following heavy rainfall, was 640 mm. There was approximately 100 mm difference in the amount of water stored between field capacity and the driest period. Infiltration characteristics of rainfall were investigated for 36 rainfall events exceeding 10 mm with a total amount of rain of 969 mm out of an annual rainfall of 1192 mm. In the case of 25 low intensity rainfall events with less than 10 mm h-1 on to dry soils, the increase in the amount of water stored to a depth of 1 m was equal to the cumulative rainfall. For rain intensity in excess of 10 mm h-1, non-uniform infiltration occurred. The increase in the amount of water stored at lower elevation locations was 1.4 to 1.6 times larger than at higher elevation locations even though the difference in ground height among the 1 m probes was 6 cm. In the two instances when rainfall exceeded 100 mm, including the amount of rain in a previous rainfall event, the increase in the amount of water stored to a depth of 1 m was 65 mm lower than the total quantity of rain on the two occasions (220 mm; this indicated that 65 mm of water or 5.5% of the annual rainfall had flowed away either by surface runoff or bypass flow. Hence, approximately 95% of the annual rainfall was absorbed by the soil matrix but it is not possible to simulate

  16. Impact of river overflowing on trace element contamination of volcanic soils in south Italy: Part I. Trace element speciation in relation to soil properties

    Energy Technology Data Exchange (ETDEWEB)

    Adamo, P. [Dipartimento di Scienze del Suolo, della Pianta e dell' Ambiente, Universita di Napoli Federico II, Via Universita 100, Portici, 80055 Naples (Italy)]. E-mail: adamo@unina.it; Zampella, M. [Dipartimento di Scienze del Suolo, della Pianta e dell' Ambiente, Universita di Napoli Federico II, Via Universita 100, Portici, 80055 Naples (Italy); Gianfreda, L. [Dipartimento di Scienze del Suolo, della Pianta e dell' Ambiente, Universita di Napoli Federico II, Via Universita 100, Portici, 80055 Naples (Italy); Renella, G. [Dipartimento di Scienza del Suolo e Nutrizione della Pianta, Universita di Firenze, P.le delle Cascine 28, 50144 Firenze (Italy); Rutigliano, F.A. [Dipartimento di Scienze Ambientali, Seconda Universita di Napoli, Via Vivaldi 43, 81100 Caserta (Italy); Terribile, F. [Dipartimento di Scienze del Suolo, della Pianta e dell' Ambiente, Universita di Napoli Federico II, Via Universita 100, Portici, 80055 Naples (Italy)

    2006-11-15

    Volcanic soils affected by different numbers of polluted river flooding events were investigated. Chromium and Cu were the major soil contaminants. Nickel, Fe, Zn and Mn total content never exceeded the Italian mandatory limits. The distribution of Cr and Cu total contents among studied soils indicated that only Cr contamination was related to overflowing events. In polluted soils, sequential chemical extractions revealed a preferential association of Cr and Cu with organic forms. A progressive Cr insolubilization with ageing was observed. Significant amounts of Cr and Cu were extracted by NH{sub 4}-oxalate, suggesting metals association with short-range-order aluminosilicates and organo-mineral complexes. Possible methodological drawbacks in the use of the EU-BCR chemical speciation protocol on volcanic soils are discussed. Micromorphology and SEM/WDS analyses revealed Cr and Cu enriched silt and clay coatings in surface and subsurface soil horizons, suggesting a transfer of metal-rich sediments along the soil pore network with water movement. - River overflowing adds up soil with Cr-rich sediments which, although chemically low reactive, transfer metal along the soil pore network during water movement.

  17. Impacts of Dust on Tropical Volcanic Soil Formation: Insights from Strontium and Uranium-Series Isotopes in Soils from Basse-Terre Island, French Guadeloupe

    Science.gov (United States)

    Pereyra, Y.; Ma, L.; Sak, P. B.; Gaillardet, J.; Buss, H. L.; Brantley, S. L.

    2015-12-01

    Dust inputs play an important role in soil formation, especially for thick soils developed on tropical volcanic islands. In these regions, soils are highly depleted due to intensive chemical weathering, and mineral nutrients from dusts have been known to be important in sustaining soil fertility and productivity. Tropical volcanic soils are an ideal system to study the impacts of dust inputs on the ecosystem. Sr and U-series isotopes are excellent tracers to identify sources of materials in an open system if the end-members have distinctive isotope signatures. These two isotope systems are particularly useful to trace the origin of atmospheric inputs into soils and to determine rates and timescales of soil formation. This study analyzes major elemental concentrations, Sr and U-series isotope ratios in highly depleted soils in the tropical volcanic island of Basse-Terre in French Guadeloupe to determine atmospheric input sources and identify key soil formation processes. We focus on three soil profiles (8 to 12 m thick) from the Bras-David, Moustique Petit-Bourg, and Deshaies watersheds; and on the adjacent rivers to these sites. Results have shown a significant depletion of U, Sr, and major elements in the deep profile (12 to 4 m) attributed to rapid chemical weathering. The top soil profiles (4 m to the surface) all show addition of elements such as Ca, Mg, U, and Sr due to atmospheric dust. More importantly, the topsoil profiles have distinct Sr and U-series isotope compositions from the deep soils. Sr and U-series isotope ratios of the top soils and sequential extraction fractions confirm that the sources of the dust are from the Saharan dessert, through long distance transport from Africa to the Caribbean region across the Atlantic Ocean. During the transport, some dust isotope signatures may also have been modified by local volcanic ashes and marine aerosols. Our study highlights that dusts and marine aerosols play important roles in element cycles and

  18. Microbial life in volcanic/geothermal areas: how soil geochemistry shapes microbial communities

    Science.gov (United States)

    Gagliano, Antonina Lisa; D'Alessandro, Walter; Franzetti, Andrea; Parello, Francesco; Tagliavia, Marcello; Quatrini, Paola

    2015-04-01

    Extreme environments, such as volcanic/geothermal areas, are sites of complex interactions between geosphere and biosphere. Although biotic and abiotic components are strictly related, they were separately studied for long time. Nowadays, innovative and interdisciplinary approaches are available to explore microbial life thriving in these environments. Pantelleria island (Italy) hosts a high enthalpy geothermal system characterized by high CH4 and low H2S fluxes. Two selected sites, FAV1 and FAV2, located at Favara Grande, the main exhalative area of the island, show similar physical conditions with a surface temperature close to 60° C and a soil gas composition enriched in CH4, H2 and CO2. FAV1 soil is characterized by harsher conditions (pH 3.4 and 12% of H2O content); conversely, milder conditions were recorded at site FAV2 (pH 5.8 and 4% of H2O content). High methanotrophic activity (59.2 nmol g-1 h-1) and wide diversity of methanotrophic bacteria were preliminary detected at FAV2, while no activity was detected at FAV1(1). Our aim was to investigate how the soil microbial communities of these two close geothermal sites at Pantelleria island respond to different geochemical conditions. Bacterial and Archaeal communities of the sites were investigated by MiSeq Illumina sequencing of hypervariable regions of the 16S rRNA gene. More than 33,000 reads were obtained for Bacteria and Archaea from soil samples of the two sites. At FAV1 99% of the bacterial sequences were assigned to four main phyla (Proteobacteria, Firmicutes, Actinobacteria and Chloroflexi). FAV2 sequences were distributed in the same phyla with the exception of Chloroflexi that was represented below 1%. Results indicate a high abundance of thermo-acidophilic chemolithotrophs in site FAV1 dominated by Acidithiobacillus ferrooxidans (25%), Nitrosococcus halophilus (10%), Alicyclobacillus spp. (7%) and the rare species Ktedonobacter racemifer (11%). The bacterial community at FAV2 soil is dominated by

  19. Effects of nitrogen sources and glucose on the consumption of ethylene and methane by temperate volcanic forest surface soils

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    There is limited knowledge with regard to the consumption of ethylene (C2H4) and methane (CH4) in volcanic forest soils containing low microbial carbon-to-organic carbon ratio, and to the responses of both consumptions to nitrogen and carbon additions. Temperate volcanic forest surface soils under three forest stands (e.g. Pinus sylvestris L., Cryptomeria japonica and Quercus serrata) were used to compare CH4 and C2H4 consumption by forest soils, and to study the effects of nitrogen sources and glucose on both consumptions. There was a good parallel between CH4 and C2H4 consumption by forest soils, but mineralization reduced CH4 consumption rather than C2H4 consumption in forest soils, particularly in a Pinus forest soil. The stimulatory effect of glucose addition on both CH4 and C2H4 consumption by forest soils was increased by increasing the pre-incubation period after glucose addition, and a largest stimulation occurred in the Pinus forest soil. The addition of KNO3-N at the rate of 100 (g·g-1 significantly reduced the consumptions of both C2H4 and CH4 by forest soils (P≤0.05). In the presence of urea plus dicyandiamide, the consumption rates of C2H4 and CH4 by forest soils were higher than those in the KNO3-N and urea-N treated soils at the same N rate (P≤0.05), but were similar to those of the control. Hence, under experimental conditions, there was a strong inhibitory effect of NO3- rather than NH4+ addition on the CH4 and C2H4 consumption in these forest soils. When amount of the added NO3-N increased up to more than 2―3 times the soil initial NO3-N concentrations, both C2H4 and CH4 consumption rates were reduced to 10%―20% of the rates in soils without nitrate addition. By comparing the three forest stands, it was shown that there was a smallest effective concentration of the added nitrate that could inhibit C2H4 and CH4 consumption in the Pinus forest soil, which indicated that C2H4 and CH4 consumption of the soil was more sensitive to NO3?-N

  20. The interaction between parent material, climate and volcanism as the major soil forming factor in the Ecuadorian high Andes region

    Science.gov (United States)

    Buytaert, W.; Duyck, H.; Dercon, G.; Deckers, J.; Wyseure, G.

    2003-04-01

    The high Andes region of Ecuador and Colombia (>3500m a.s.l.) is covered by the so-called páramo ecosystem, characterised by a cold climate, a typical grass or small shrub vegetation and volcanic soils. Soil profiles of the paramo in the Austro Ecuatoriano, South Ecuador, were studied in order to reveal genetic relationships with geology, volcanic ash deposits, climate and land use. A gradual diminuation of Andic properties was found, related to the distance of the pedon to the active volcanoes of the Northern Volcanic Zone of the Andes. Pedons in the north of the region, closer to these volcanoes (Sangay, Tungurahua) are classified as non-allophanic Histic Andosols. The influence of the vicinity of the volcanoes leads to a higher oxalate extractable aluminium and iron. The genesis of the Andosols seems to be strongly related to the presence and thickness of volcanic ash depositions. The limit of these depositions is situated south of the city of Cuenca. Pedons further to the south are classified as Histosols. However, they also have clear Andic properties. Several differences in chemical properties between the Western and Eastern cordilleras where found, that are most probable related with a difference in mother material, and maybe also a different climatic regime. Correlation of the chemical properties with land use reveals that no chemical differences can be found that are invoked by occupying natural Andosols for agricultural purposes, within the first five years of cultivation. At last, the conclusions were used to revisit the World Reference Base for Soil Resources in order to sharpen up differenciation between Andosols and Histosols.

  1. Application of organic matter and biofertilizer to improve growth and yield of maize on soil damaged by volcanic ash of Mount Kelud in East Java

    Directory of Open Access Journals (Sweden)

    S. Hardianita

    2015-07-01

    Full Text Available Volcanic ash from the eruption of Mount Kelud in 2014 damaged some agricultural areas grown with maize in Malang of East Java. The purpose of this study was to elucidate the effect of organic fertilizers and biological fertilizers on growth and yield of maize on soils damaged by volcanic ash from the eruption of Mount Kelud. A pot experiment was conducted in the glasshouse of Balitkabi, Kendalpayak, Malang from July 2014 to February 2015. The treatments tested in this study were combinations of three mixtures of soil and volcanic ash (90%:10%, 80%:20%, and 70%:30%, and two doses of biofertilizer (25 and 35 kg / ha. Each treatment was added with 5 t organic matter/ha. A total of 10 kg of each mixture of soil and volcanic ash was placed in a 15 kg plastic pot. Each treatment received 100 kg inorganic fertilizer / kg containing 15% N, 15% P, and 15% K. Three seeds of maize (NK33 variety were planted in each pot and thin to one plant after one week. The experiment was conducted for 14 weeks. The results showed that application of organic matter and biofertilizer did not significantly improve fertility of soil mixed with volcanic ash from the eruption of Mount Kelud. Yield of maize was not significantly improved by the application of organic matter and biofertilizer on soil mixed with volcanic ash. The contents of carbohydrates and proteins in maize seeds were also not affected by application of organic matter and biofertilizer.

  2. Effect of long-term different fertilization on bacterial community structures and diversity in citrus orchard soil of volcanic ash.

    Science.gov (United States)

    Joa, Jae Ho; Weon, Hang Yeon; Hyun, Hae Nam; Jeun, Young Chull; Koh, Sang Wook

    2014-12-01

    This study was conducted to assess bacterial species richness, diversity and community distribution according to different fertilization regimes for 16 years in citrus orchard soil of volcanic ash. Soil samples were collected and analyzed from Compost (cattle manure, 2,000 kg/10a), 1/2 NPK+compost (14-20-14+2,000 kg/10a), NPK+compost (28-40-28+2,000 kg/10a), NPK (28-40-28 kg/10a), 3 NPK (84-120-84 kg/10a), and Control (no fertilization) plot which have been managed in the same manners with compost and different amount of chemical fertilization. The range of pyrosequencing reads and OTUs were 4,687-7,330 and 1,790-3,695, respectively. Species richness estimates such as Ace, Chao1, and Shannon index were higher in 1/2 NPK+compost than other treatments, which were 15,202, 9,112, 7.7, respectively. Dominant bacterial groups at level of phylum were Proteobacteria, Acidobacteria, and Actinobacteria. Those were occupied at 70.9% in 1/2 NPK+compost. Dominant bacterial groups at level of genus were Pseudolabrys, Bradyrhizobium, and Acidobacteria. Those were distributed at 14.4% of a total of bacteria in Compost. Soil pH displayed significantly closely related to bacterial species richness estimates such as Ace, Chao1 (pfertilization management, soil pH changes and characteristics of volcanic ash. PMID:25467117

  3. The use of volcanic ash from the eruption of Mount Kelud in East Java for improving yield of sweet potato grown on a sandy soil

    Directory of Open Access Journals (Sweden)

    H. Melsandi

    2015-07-01

    Full Text Available The purpose of this study was to explore the effect of volcanic ash from the eruption of Mount Kelud and compost on the soil properties and production of sweet potato on a sandy soil. The treatments of this study were (a a combination of and volcanic ash with the proportion of 100: 0, 90:10, 80:20, and 70:30 (% weight, (b the addition of compost (2.5 and 5 t / ha, and (c two varieties of sweet potato (Manohara and Ayamurazaki. The soil used in this study is the topsoil (0-30 cm Psament or sandy Entisol obtained from sweet potato cultivation location in Sumber Pasir Village of Pakis District, South Malang. Ten kilograms of planting medium (soil + volcanic ash for each treatment was placed in a 15 kg plastic pot. Sixteen treatments arranged in a factorial completely randomized design with three replications. The results showed that application of Mount Kelud volcanic ash and compost was able to improve soil permeability, soil pH, organic C, and K-total, but did not significantly affect total N content, available P and K total land. The highest fresh tuber weights of 373.51 g / plant or 19.92 t / ha and 393.09 g / plant or 20.96 t / ha for Manohara and Ayumurazaki varieties, respectively, were observed in the treatment of 10% volcanic ash + 5 t compost / ha. The carbohydrate content of Manohara variety was higher than that of Ayamurazaki variety at each treatment. The highest carbohydrate content of the Manohara variety (23.52% was obtained through application of 20% volcanic ash + 2.5 t compost/ha, while that of the Ayamurazaki variety (22.42% was obtained through application of 30% volcanic ash + 2.5 t/ha.

  4. Volcanic soils and landslides: the case study of the Ischia island (southern Italy) and relationship with other Campania events

    Science.gov (United States)

    Vingiani, S.; Mele, G.; De Mascellis, R.; Terribile, F.; Basile, A.

    2015-01-01

    An integrated investigation has been carried out over the soils involved in the landslide phenomena occurred in the 2006 at Mt. Vezzi in the Ischia island (southern Italy). Chemical, physical (i.e. particle size distribution, hydrological analyses and direct measurements of soil porosity), mineralogical and micromorphological properties of three soil profiles selected in two of the main detachment crowns were analysed. The studied soils, having a volcanic origin, showed a substantial abrupt discontinuity of all the studied properties in correspondence of the 2C horizon, also identified as sliding surface of the landslide phenomena. With respect to the above horizons, the 2C showed (i) as a grey fine ash, almost pumices free, with a silt content increased by the 20%, (ii) ks values one order of magnitude lower, (iii) a porosity concentrated in the small size (15 to 30 μm modal class) pores characterized by very low percolation threshold (around 15-25 μm), (iv) occurrence of expandable clay minerals and (v) higher Na content in the exchange complex. Therefore, most of these properties indicated 2C as a lower permeability horizon than the above. Nevertheless, only the identification of a thin (6.5 mm) finely stratified ash layer on the top of 2C enabled to assume this interface as an impeding layer to vertical and horizontal water fluxes, as testified by the hydromorphic features (e.g. Fe / Mn concretions) within and on the top of the layer. Despite the Mt. Vezzi soil environment has many properties (high gradient northern facing slope, similar forestry, volcanic origin of the parent material) in common with those of many Campania debris-mud flows, the results of this study did not support the found relationship between Andosols and debris-mudflows, but emphasize the role of vertical discontinuities as landslide predisposing factor.

  5. Volcanic soils and landslides: the case study of the Ischia island (southern Italy and relationship with other Campania events

    Directory of Open Access Journals (Sweden)

    S. Vingiani

    2015-01-01

    Full Text Available An integrated investigation has been carried out over the soils involved in the landslide phenomena occurred in the 2006 at Mt. Vezzi in the Ischia island (southern Italy. Chemical, physical (i.e. particle size distribution, hydrological analyses and direct measurements of soil porosity, mineralogical and micromorphological properties of three soil profiles selected in two of the main detachment crowns were analysed. The studied soils, having a volcanic origin, showed a substantial abrupt discontinuity of all the studied properties in correspondence of the 2C horizon, also identified as sliding surface of the landslide phenomena. With respect to the above horizons, the 2C showed (i as a grey fine ash, almost pumices free, with a silt content increased by the 20%, (ii ks values one order of magnitude lower, (iii a porosity concentrated in the small size (15 to 30 μm modal class pores characterized by very low percolation threshold (around 15–25 μm, (iv occurrence of expandable clay minerals and (v higher Na content in the exchange complex. Therefore, most of these properties indicated 2C as a lower permeability horizon than the above. Nevertheless, only the identification of a thin (6.5 mm finely stratified ash layer on the top of 2C enabled to assume this interface as an impeding layer to vertical and horizontal water fluxes, as testified by the hydromorphic features (e.g. Fe / Mn concretions within and on the top of the layer. Despite the Mt. Vezzi soil environment has many properties (high gradient northern facing slope, similar forestry, volcanic origin of the parent material in common with those of many Campania debris-mud flows, the results of this study did not support the found relationship between Andosols and debris-mudflows, but emphasize the role of vertical discontinuities as landslide predisposing factor.

  6. Application of organic matter and biofertilizer to improve growth and yield of maize on soil damaged by volcanic ash of Mount Kelud in East Java

    OpenAIRE

    S. Hardianita; R.M. Bosas; Y. Nuraini

    2015-01-01

    Volcanic ash from the eruption of Mount Kelud in 2014 damaged some agricultural areas grown with maize in Malang of East Java. The purpose of this study was to elucidate the effect of organic fertilizers and biological fertilizers on growth and yield of maize on soils damaged by volcanic ash from the eruption of Mount Kelud. A pot experiment was conducted in the glasshouse of Balitkabi, Kendalpayak, Malang from July 2014 to February 2015. The treatments tested in this study were combinations ...

  7. Lichen-rock interaction in volcanic environments: evidences of soil-precursor formation

    Science.gov (United States)

    Vingiani, S.; Adamo, P.; Terribile, F.

    2012-04-01

    The weathering action of the lichens Lecidea fuscoatra (L.) Ach. and Stereocaulon vesuvianum Pers. on basaltic rock collected on the slopes of Mt. Etna (Sicily) at 1550 m a.s.l. has been studied using optical (OM) and electron (SEM) microscopy equipped with microanalytical device (EDS). Biological factors associated with lichen growth play a major role in the weathering of minerals on bare rocks and contribute to the preliminary phases of soil formation. The present work investigates the biogeophysical and biogeochemical weathering associated to the growth of epilithic lichens on lava flows from Mt. Etna (Sicily) and Mt. Vesuvius (Campania). The chosen lichen species were the crustose Lecidea fuscoatra (L.) Ach., the foliose Xanthoparmelia conspersa and the fructicose Stereocaulon vesuvianum Pers. An integrated approach based on the study of both disturbed and undisturbed samples of lichenized rock was applied in order to appreciate the complexity of the rock-lichen interface environment in terms of micromorphological, mineralogical and chemical properties. XRD and XRF analyses coupled to microscopical (OM), submicroscopical (SEM) and microanalitical (EDS) observations were the used techniques. In both study environments, the chemical, mineralogical and micromorphological properties of the uncoherent materials found at the lichen-rock interface suggest they consist of rock fragments eroded from the surroundings and accumulated in cavities and fissures of the rough lava flows. According to the thallus morphology, the lichens colonizing the lava preserve the interface materials from further aeolic and water erosion, provide these materials of organic matter and moisture, entrap allochtonous quartz and clay minerals. The calcium oxalate production by L. fuscoatra and X. conspersa, the Al enrichment around S. vesuvianum hyphae and the occurrence of Fe-oxide phases at the rock-lichen interface are evidences of lichens interaction with the underlying sediments. Indeed

  8. Effects of seagulls on ecosystem respiration, soil nitrogen and vegetation cover on a pristine volcanic island, Surtsey, Iceland

    Directory of Open Access Journals (Sweden)

    B. D. Sigurdsson

    2010-03-01

    Full Text Available When Surtsey rose from the North Atlantic Ocean south of Iceland in 1963, it became a unique natural laboratory on how organisms colonize volcanic islands and form ecosystems with contrasting structures and functions. In July, 2004, ecosystem respiration rate (Re, soil properties and surface cover of vascular plants were measured in 21 permanent research plots distributed among the juvenile communities of the island. The plots were divided into two main groups, inside and outside a seagull (Larus spp. colony established on the island. Vegetation cover of the plots was strongly related to the density of gull nests. Occurrence of nests and increased vegetation cover also coincided with significant increases in Re, soil carbon, nitrogen and C:N ratio, and with significant reductions in soil pH and soil temperatures. Temperature sensitivity (Q10 value of Re was determined as 5.3. When compared at constant temperature the Re was found to be 59 times higher within the seagull colony, similar to the highest fluxes measured in drained wetlands or agricultural fields in Iceland. The amount of soil nitrogen, mainly brought onto the island by the seagulls, was the critical factor that most influenced ecosystem fluxes and vegetation development on Surtsey. The present study shows how ecosystem activity can be enhanced by colonization of animals that transfer resources from a nearby ecosystem.

  9. Land use and Hydrological Characteristics of Volcanic Urban Soils for Flood Susceptibility Modeling, Ciudad de Colima (Mexico)

    Science.gov (United States)

    Perez Gonzalez, M. L.; Capra, L.; Borselli, L.; Ortiz, A.

    2015-12-01

    The fast population rate growth and the unplanned urban development has created an increase of urban floods in the City of Colima. Land use change has transformed the hydrological behavior of the watersheds that participates on the runoff-infiltration processes that governs the pluvial concentrations. After the urban areas enlargement, 13% from 2010 to 2015, rainfall has caused significant damages to the downtown community. Therefore it is important to define the main hydraulic properties of the soils surrounding the city. The soil of the region is derived from the debris avalanche deposits of the Volcano of Colima. The volcanic soil cover is only 10 to 15 cm depth. To test the soils of the region, sampling locations were chosen after making a land use map from a Landsat image. The map was done by selecting and dividing similar surface images patterns into three main classifications: Natural (N1), Agricultural (N5) and Urban (N4) surfaces. Thirty-Three soil samples were collected and grouped in nine out of ten land use subdivisions. The 10thsubdivision, represents the completed urbanized area. The land use model is made using spot 4 1A images from the year 2010 up to year 2015. This land use evolutionary analysis will be a base to evaluate the change of the runoff-infiltration rate, direction, and concentration areas for the future flood susceptibility model. To get the parameters above, several soil analysis were performed. The results were that all the soil samples tested were classified as sandy soils. The water content values were from 7% (N4) to 45% (N1) while bulk density values for the same sample were form 0.65 (N1) to 1.50 (N4) g/cm3. The particle density and the porosity values were from 1.65 g/cm3 /5.5% (N4) - 2.65 g/cm3/ 75.40% (N1). The organic matter content was around 0.1% for urban soils and up to 6% on natural and agricultural soils. Some other test like electric conductivity and pH were performed. The obtained parameters were used to get other

  10. Impact of river overflowing on trace element contamination of volcanic soils in south Italy: Part II. Soil biological and biochemical properties in relation to trace element speciation

    Energy Technology Data Exchange (ETDEWEB)

    D' Ascoli, R. [Dipartimento di Scienze Ambientali, Seconda Universita degli Studi di Napoli, via Vivaldi 43, 81100 Caserta (Italy)]. E-mail: rosaria.dascoli@unina2.it; Rao, M.A. [Dipartimento di Scienze del Suolo, della Pianta e dell' Ambiente, Universita degli Studi di Napoli Federico II, Via Universita 100, 80055 Portici (Italy)]. E-mail: maria.rao@unina.it; Adamo, P. [Dipartimento di Scienze del Suolo, della Pianta e dell' Ambiente, Universita degli Studi di Napoli Federico II, Via Universita 100, 80055 Portici (Italy)]. E-mail: adamo@unina.it; Renella, G. [Dipartimento di Scienza del Suolo e Nutrizione della Pianta, Universita degli Studi di Firenze, P.le delle Cascine 28, 50144 Firenze (Italy)]. E-mail: giancarlo.renella@unifi.it; Landi, L. [Dipartimento di Scienza del Suolo e Nutrizione della Pianta, Universita degli Studi di Firenze, P.le delle Cascine 28, 50144 Firenze (Italy)]. E-mail: loretta.landi@unifi.it; Rutigliano, F.A. [Dipartimento di Scienze Ambientali, Seconda Universita degli Studi di Napoli, via Vivaldi 43, 81100 Caserta (Italy)]. E-mail: floraa.rutigliano@unina2.it; Terribile, F. [Dipartimento di Scienze del Suolo, della Pianta e dell' Ambiente, Universita degli Studi di Napoli Federico II, Via Universita 100, 80055 Portici (Italy)]. E-mail: terribil@unina.it; Gianfreda, L. [Dipartimento di Scienze del Suolo, della Pianta e dell' Ambiente, Universita degli Studi di Napoli Federico II, Via Universita 100, 80055 Portici (Italy)]. E-mail: liliana.gianfreda@unina.it

    2006-11-15

    The effect of heavy metal contamination on biological and biochemical properties of Italian volcanic soils was evaluated in a multidisciplinary study, involving pedoenvironmental, micromorphological, physical, chemical, biological and biochemical analyses. Soils affected by recurring river overflowing, with Cr(III)-contaminated water and sediments, and a non-flooded control soil were analysed for microbial biomass, total and active fungal mycelium, enzyme activities (i.e., FDA hydrolase, dehydrogenase, {beta}-glucosidase, urease, arylsulphatase, acid phosphatase) and bacterial diversity (DGGE characterisation). Biological and biochemical data were related with both total and selected fractions of Cr and Cu (the latter deriving from agricultural chemical products) as well as with total and extractable organic C. The growth and activity of soil microbial community were influenced by soil organic C content rather than Cu or Cr contents. In fact, positive correlations between all studied parameters and organic C content were found. On the contrary, negative correlations were observed only between total fungal mycelium, dehydrogenase, arylsulphatase and acid phosphatase activities and only one Cr fraction (the soluble, exchangeable and carbonate bound). However, total Cr content negatively affected the eubacterial diversity but it did not determine changes in soil activity, probably because of the redundancy of functions within species of soil microbial community. On the other hand, expressing biological and biochemical parameters per unit of total organic C, Cu pollution negatively influenced microbial biomass, fungal mycelium and several enzyme activities, confirming soil organic matter is able to mask the negative effects of Cu on microbial community. - In studied soils organic C content resulted the principal factor influencing growth and activity of microbial community, with Cu and Cr contents having a lower relevance.

  11. Efecto de la fertilización fosforada sobre el contenido de cadmio en cuatro suelos de Chile Effect of phosphate fertilizer on the soil cadmium content in four types of Chilean soils

    Directory of Open Access Journals (Sweden)

    Claudia Bonomelli

    2003-10-01

    Full Text Available Los fertilizantes fosforados pueden contener cadmio (Cd y al utilizarlos pueden entrar en las cadenas tróficas. El objetivo de este estudio fue evaluar el efecto de la fertilización fosforada sobre la concentración de Cd disponible en cuatro tipos de suelos de Chile, que pertenecían a los ordenes Inceptisol, Alfisol, Ultisol y Andisol. Los dos tratamientos usados fueron el testigo sin fertilización y la aplicación de una dosis de corrección con un fertilizante comercial, superfosfato triple (SFT, que tenía una concentración de 53,2 mg de Cd por kg de fertilizante. La dosis de fertilizante aplicada fue la necesaria para alcanzar un nivel de 30 mg kg-1 de POlsen. Los suelos se incubaron en estufa durante 90 días, a 25ºC y humedad de capacidad de campo. El diseño experimental fue completamente al azar, con tres repeticiones para cada suelo y donde la unidad experimental fue un contenedor con 250 g de suelo seco. Se midió Cd disponible a los 1, 2, 7, 14, 21, 36, 49, 63, 77 y 90 días después de la incubación. La aplicación de P en dosis agronómica, utilizando fertilizante con alto contenido de Cd, tuvo un efecto estadísticamente significativo sobre la concentración de Cd disponible en los suelos estudiados, sin embargo, no hubo efecto del tiempo de incubación en la disponibilidad de Cadmio.Phosphate fertilizers may contain cadmiun (Cd which may become part of the trophic chains. The objective of this study was to evaluate the effect of phosphate fertilizer on available Cd content in four Chilean soil types, belonging to orders Alfisol, Inceptisol, Ultisol and Andisol. Treatments consisted of control without P fertilizer and P application with commercial triple superphosphate containing 53.2 mg Cd per kg of fertilizer. The dose of phosphate fertilizer applied was enough to reach the level of 30 mg kg-1 POlsen. The soils were incubated up to 90 days, at 25ºC and field capacity. The experimental design was completely randomized

  12. Strontium isotopes provide clues for a process shift in base cation dynamics in young volcanic soils

    Science.gov (United States)

    Bingham, N.; Jackson, M. G.; Bookhagen, B.; Maher, K.; Chadwick, O.

    2015-12-01

    Despite advances in soil development theory based on studies of old soils or over long timescales, little is known about soil thresholds (dramatic changes in soil properties associated with only small shifts in external forcing factors) that might be expressed in young soils (less than 10 kyr). Therefore, we seek to understand infant soil development in a tropical environment through the sourcing of plant available base cations by measuring the strontium (Sr) isotopic composition of the soil exchange complex. Our sampling strategy spans soils in three different precipitation ranges (950-1060 mm, 1180-1210 mm, and 1450-1500) and an array of soil ages from 500 to 7500 years in the Kona region on the island of Hawaii. In Hawaiian soils, 87Sr/86Sr values are determined by a mixture of three components: a mantle-derived component from the lava (0.7034), a rainfall component (0.7093) and a component from continental dust (0.720). Elevation-controlled leaching intensity in the wettest localities produces a decline in the concentration of base cations supplied by basalt and a dilute resupply by rainfall. In the driest sites, where leaching intensity is dramatically reduced, there is a buildup of rainfall-derived extractable Sr in the soil over time. Slow rock weathering rates produce a small rock-derived cation input to the soil. Thus, Sr isotope signatures reflect both the input of rainfall-derived cations and rock-derived cations with values that fall between rainfall and basaltic signatures. Soils in the intermediate precipitation range have Sr isotopic signatures consistent with both the wet and dry trends; suggesting that they lie close to the critical precipitation amount that marks a shift between these two processes. For the Kona region, this transition seems to occur at 1200 mm /yr. In contrast to the clear-cut differentiation in strontium isotopes with precipitation shifts observed in older soils, patterns on these young soils in Kona are complicated by low soil

  13. Radiocaesium (Cs-137) fallout in Iceland and its behaviour in subarctic volcanic soils

    Energy Technology Data Exchange (ETDEWEB)

    Sigurgeirsson, M.A.; Palsson, S.E.; Gudnason, K. [Icelandic Radiation Protection Inst., Reykjavik (Iceland); Arnalds, O. [Agricultural Research Inst. (Iceland)

    2002-04-01

    In the autumn of 2000 the Icelandic Radiation Protection Institute began systematic analysis of radiocaesium in Icelandic soils. The main objectives of the study are to investigate the spatial variation of radiocaesium concentration in Iceland and make estimates of the retention of Cs-137 in major soil types. Soil samples from 17 sampling sites were collected. Soils were sampled with a 17 mm sampling probe. Twenty cores were collected at each site at even intervals along a 20 m on line. The concentration of Cs-137 was measured using HPGe spectrometry. The main results gained so far are the following: a) Total activity per unit area of Cs-137 was found to be 900-4700 Bglm{sup 2}. b) In all cases > 85 % of Cs-137 in soils is fixed in the uppermost 15 cm of the soil cover. c) In loam and sandy loam 60-95 % of Cs-137 is fixed in the top layer of the soil (i.e. 0-5 cm interval). In sandy loam and loamy sand (Vitric Andosols) considerable amount of Cs is fixed in deeper layers, i.e. below 5 cm depth, indicating that mobility of Cs-137 is dependent on grain size distribution and clay content of the soil. Former studies indicate that Cs is rather mobile in Icelandic soils. d) In pieat (Histosols) 80-85% of Cs-137 is bound in the top layer of the soil (0-5 cm) and 10-15% within the 5-10 cm depth range. e) Comparison of samples obtained form undisturbed hayfield and uncultivated land at the same site (i.e. MYR) showed lower concentration of Cs-137 in the top layer of the hayfield but on the other hand higher total activity per unit area. Sample from GRI, collected in a hayfield, shows similar behaviour of Cs-137 as in MYRa. f) Good correlation was obtained between precipitation and total activity of radiocaesium in soils. In the autumn of 2000 the Icelandic Radiation Protection Institute began systematic analysis of radiocaesium in Icelandic Soils. The main objectives of the study are to investigate the spatial variation of radiocaesium concentration in Iceland and make

  14. Radiocaesium (Cs-137) fallout in Iceland and its behaviour in subarctic volcanic soils

    International Nuclear Information System (INIS)

    In the autumn of 2000 the Icelandic Radiation Protection Institute began systematic analysis of radiocaesium in Icelandic soils. The main objectives of the study are to investigate the spatial variation of radiocaesium concentration in Iceland and make estimates of the retention of Cs-137 in major soil types. Soil samples from 17 sampling sites were collected. Soils were sampled with a 17 mm sampling probe. Twenty cores were collected at each site at even intervals along a 20 m on line. The concentration of Cs-137 was measured using HPGe spectrometry. The main results gained so far are the following: a) Total activity per unit area of Cs-137 was found to be 900-4700 Bglm2. b) In all cases > 85 % of Cs-137 in soils is fixed in the uppermost 15 cm of the soil cover. c) In loam and sandy loam 60-95 % of Cs-137 is fixed in the top layer of the soil (i.e. 0-5 cm interval). In sandy loam and loamy sand (Vitric Andosols) considerable amount of Cs is fixed in deeper layers, i.e. below 5 cm depth, indicating that mobility of Cs-137 is dependent on grain size distribution and clay content of the soil. Former studies indicate that Cs is rather mobile in Icelandic soils. d) In pieat (Histosols) 80-85% of Cs-137 is bound in the top layer of the soil (0-5 cm) and 10-15% within the 5-10 cm depth range. e) Comparison of samples obtained form undisturbed hayfield and uncultivated land at the same site (i.e. MYR) showed lower concentration of Cs-137 in the top layer of the hayfield but on the other hand higher total activity per unit area. Sample from GRI, collected in a hayfield, shows similar behaviour of Cs-137 as in MYRa. f) Good correlation was obtained between precipitation and total activity of radiocaesium in soils. In the autumn of 2000 the Icelandic Radiation Protection Institute began systematic analysis of radiocaesium in Icelandic Soils. The main objectives of the study are to investigate the spatial variation of radiocaesium concentration in Iceland and make estimates

  15. Ammonia emission from a permanent grassland on volcanic soil after the treatment with dairy slurry and urea

    Science.gov (United States)

    Salazar, F.; Martínez-Lagos, J.; Alfaro, M.; Misselbrook, T.

    2014-10-01

    Ammonia (NH3) is an air pollutant largely emitted from agricultural activities including the application of livestock manures and fertilizers to grassland. This gas has been linked with important negative impacts on natural ecosystems. In southern Chile, the use of inorganic and organic fertilizers (e.g. slurries) has increased in cattle production systems over recent years, heightening the risk of N losses to the wider environment. The objectives of this study were to evaluate on permanent grasslands on a volcanic ash soil in southern Chile: 1) the N loss due to NH3 volatilization following surface application of dairy slurry and urea fertilizer; and 2) the effect of a urease inhibitor on NH3 emissions from urea fertilizer application. Small plot field experiments were conducted over spring, fall, winter and summer seasons, using a system of wind tunnels to measure ammonia emissions. Ammonia losses ranged from 1.8 (winter) to 26.0% (fall) and 3.1 (winter) to 20.5% (summer) of total N applied for urea and slurry, respectively. Based on the readily available N applied (ammoniacal N for dairy slurry and urea N for urea fertilizer), losses from dairy slurry were much greater, at 16.1 and 82.0%, for winter and summer, respectively. The use of a urease inhibitor proved to be an effective option to minimize the N loss due NH3 volatilization from urea fertilizer, with an average reduction of 71% across all seasons. The results of this and other recent studies regarding N losses suggest that ammonia volatilization is the main pathway of N loss from grassland systems in southern Chile on volcanic ash soils when urea and slurry are used as an N source. The use of good management practices, such as the inclusion of a urease inhibitor with urea fertilizer could have a beneficial impact on reducing N losses due NH3 volatilization and the environmental and economic impact of these emissions.

  16. Development of Bioavailable Pools of Base Cations and P after Afforestation of Volcanic Soils in Iceland

    DEFF Research Database (Denmark)

    Ritter, Eva

    2009-01-01

    Few long-term studies have been conducted on changes in soil nutrients after afforestation in Iceland, a country with a young history of forest management. While fertilization was shown to improve survival of seedlings in the first years after planting on the nutrient limited soils, knowledge abo...

  17. Changes in the sorption, desorption, distribution, and availability of copper, induced by application of sewage sludge on Chilean soils contaminated by mine tailings

    Institute of Scientific and Technical Information of China (English)

    Tatiana Garrido; Jorge Mendoza; Francisco Arriagada

    2012-01-01

    The effect of mine tailings and sewage sludge was evaluated on sorption,desorption,availability and distribution of copper in two soils,one high (sandy soil) and one low in copper (clay soil).In both soils contaminated by mine tailings the copper sorption capacity and the affinity of the substrate for the metal decreased substantially compared to the uncontaminated soils,however,the sorption remained always high in the clay soil substrates.In the substrates with sandy soil,the high Cu content and lower clay content were determining factors in the lower magnitude of the sorption.Similarly,metal desorption was closely related to these two parameters,and it was higher in clay soil with lower pH.In general,the application of sewage sludge favored the sorption of Cu in soils contaminated and uncontaminated with mine tailings,and in all cases desorption decreased,an effect that remained for at least 30 days.Simple extraction of Cu with CaCl2 and diethylenetriaminepentaacetic acid gave contradictory results,so a careful choice of the procedure is required,depending on the level of metal in the soil and on the acting principle of the extracting agent.In that relation,more complete information on the changes in the metal forms was obtained by application of the sequential extraction procedure proposed by the European Community Bureau of Reference.

  18. Carbon flow from volcanic CO2 into soil microbial communities of a wetland mofette

    Science.gov (United States)

    Beulig, Felix; Heuer, Verena B.; Akob, Denise M.; Viehweger, Bernhard; Elvert, Marcus; Herrmann, Martina; Hinrichs, Kai-Uwe; Küsel, Kirsten

    2015-01-01

    Effects of extremely high carbon dioxide (CO2) concentrations on soil microbial communities and associated processes are largely unknown. We studied a wetland area affected by spots of subcrustal CO2 degassing (mofettes) with focus on anaerobic autotrophic methanogenesis and acetogenesis because the pore gas phase was largely hypoxic. Compared with a reference soil, the mofette was more acidic (ΔpH ~0.8), strongly enriched in organic carbon (up to 10 times), and exhibited lower prokaryotic diversity. It was dominated by methanogens and subdivision 1Acidobacteria, which likely thrived under stable hypoxia and acidic pH. Anoxic incubations revealed enhanced formation of acetate and methane (CH4) from hydrogen (H2) and CO2 consistent with elevated CH4 and acetate levels in the mofette soil. 13CO2 mofette soil incubations showed high label incorporations with ~512 ng13C g (dry weight (dw)) soil−1 d−1 into the bulk soil and up to 10.7 ng 13C g (dw) soil−1 d−1 into almost all analyzed bacterial lipids. Incorporation of CO2-derived carbon into archaeal lipids was much lower and restricted to the first 10 cm of the soil. DNA-SIP analysis revealed that acidophilic methanogens affiliated withMethanoregulaceae and hitherto unknown acetogens appeared to be involved in the chemolithoautotrophic utilization of 13CO2. Subdivision 1 Acidobacteriaceae assimilated 13CO2 likely via anaplerotic reactions because Acidobacteriaceae are not known to harbor enzymatic pathways for autotrophic CO2 assimilation. We conclude that CO2-induced geochemical changes promoted anaerobic and acidophilic organisms and altered carbon turnover in affected soils.

  19. Volcanic monitoring for radon and chemical species in the soil and in spring water samples

    Energy Technology Data Exchange (ETDEWEB)

    Segovia, N. E-mail: nurina@terra.com.mx; Armienta, M.A.; Valdes, C.; Mena, M.; Seidel, J.L.; Monnin, M.; Pena, P.; Lopez, M.B.E.; Reyes, A.V

    2003-06-01

    Soil radon has been monitored at two fixed stations in the northern flank of Popocatepetl Volcano, a high risk volcano located 60 km SE from Mexico City. Water samples from three springs were also studied for radon as well as major and trace elements. Radon in the soil was recorded using track detectors. Radon in the water samples was evaluated using the liquid scintillation method and an Alphaguard. The major elements were determined through conventional chemical methods and trace elements using an ICP-MS equipment. Soil radon levels were low, indicating a moderate diffuse degassing through the flanks of the volcano. Groundwater radon had almost no relation with the eruptive stages. Water chemistry was stable in the reported time (2000-2002)

  20. Soil gas measurements as an indicator of volcanic activity at Popocatepetl, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Varley, N.R.; Armienta, M.A. [Inst. de Geofisica, Circuito Cientifico (Mexico)

    1999-08-01

    Recently Popocatepetl has commenced a new active phase with several explosive events producing ash falls at large variation. For a better understanding of the processes occurring within the volcano, as well as its structure, further data of different types is required. This study will include an extensive program of soil gas measurements, including radon, carbon dioxide, methane and helium. A comparison will be made with seismic and groundwater and ash geochemical data. One goal will be an improved understanding of the mechanism whereby seismic events influence the concentration of soil gases, which is not currently well understood. Here the preliminary data are presented.

  1. Dissolved Organic Matter as a Mechanism for Carbon Stabilization at Depth in Wet Tropical Forest Volcanic Soils

    Science.gov (United States)

    Marin-Spiotta, E.; Kramer, M. G.; Chadwick, O. A.

    2007-12-01

    Dissolved organic matter (DOM) plays an important role in many biological and chemical processes in soils. Our understanding of the types of plant and microbially-derived organic matter that accumulate in soils and the mechanisms responsible for their transformation and stabilization is still limited. In particular, we know very little about how microbial activity and water movement contribute to the production of DOM and the formation of stable C in soils. In well-drained soils under wet climates, DOM is potentially a primary pathway for the transport of C from the surface litter layers and the zones of highest microbial activity to deeper horizons in the soil profile where the potential for long-term storage increases. The mechanisms for long-term stabilization of organic C in deep mineral horizons include an accumulation of chemically recalcitrant C, strong sorption of soluble and otherwise labile C to mineral and/or metals making them inaccessible to decomposers, and microenvironmental conditions (low pH, low O2) which result in incomplete decomposition and persistence of labile C. Although most work to date has focused on the role of dissolved organic C and N (DOC and DON) in the C and N cycles of temperate forests, DOM fluxes may be even more important in forests in the wet tropics, where high rainfall and high primary productivity could lead to greater DOM production. In order to address the role of DOC in the transport and stabilization of C in mineral horizons, we are studying DOC production, transformation, and loss pathways in volcanic soils dominated by highly reactive, non-crystalline minerals (allophane). We are quantifying flux and solute concentrations (C, N, cations, anions) in rainwater, throughfall, and in soil water. We have installed tension and zero tension lysimeters throughout sequentially deeper organic and mineral horizons in an intermediate aged soil (ca. 350k years) under wet (ca. 3000 mm mean annual rainfall) native tropical forest

  2. The emissions and soil concentrations of N2O and CH4 from natural soil temperature gradients in a volcanic area in southwest Iceland

    Science.gov (United States)

    Maljanen, Marja; Yli-Moijala, Heli; Leblans, Niki I. W.; De Boeck, Hans J.; Bjarnadóttir, Brynhildur; Sigurdsson, Bjarni D.

    2016-04-01

    We studied nitrous oxide (N2O) and methane (CH4) emissions along three natural geothermal soil temperature (Ts) gradients in a volcanic area in southwest Iceland. Two of the gradients (on a grassland and a forest site, respectively) were recently formed (in May 2008). The third gradient, a grassland site, had been subjected to long-term soil warming (over 30 years, and probably centuries). Nitrous oxide and methane emissions were measured along the temperature gradients using the static chamber method and also soil gas concentrations were studied. With a moderate soil temperature increase (up to +5 °C) there were no significant increase in gas flux rates in any of the sites but an increase of 20 to 45 °C induced an increase in both N2O and CH4 emissions. The measured N2O emissions (up to 2600 μg N2O m-2 h-1) from the warmest plots were about two magnitudes higher compared with the coolest plots (less than 20 μg N2O m-2 h-1). While a net uptake of CH4 was measured in the coolest plots (up to -0.15 mg CH4 m-2 h-1), a net emission of CH4 was measured from the warmest plots (up to 1.3 mg CH4 m-2 h-1). Soil CH4 concentrations decreased first with a moderate (up to +5 °C) increase in Ts, but above that threshold increased significantly. The soil N2O concentration at depths from 5 to 20 cm increased with increasing Ts, indicating enhanced N-turnover. Further, there was a clear decrease in soil organic matter (SOM), C- and N concentration with increasing Ts at all sites. One should note, however, that a part of the N2O emitted from the warmest plots may be partly geothermally derived, as was revealed by 15N2O isotope studies. These natural Ts gradients show that the emission of N2O and CH4 can increase significantly when Ts increases considerably. This implies that these geothermally active sites can act as local hot spots for CH4 and N2O emissions.

  3. Runoff and erosion effects after prescribed fire and wildfire on volcanic ash-cap soils

    Science.gov (United States)

    AFTER PRESCRIBED BURNS AT THREE LOCATIONS AND ONE WILDFIRE, RAINFALL SIMULATIONS STUDIES WERE COMPLETED TO COMPARE POSTFIRE RUNOFF RATES AND SEDIMENT YIELDS ON ASH-CAP SOIL IN CONIFER FOREST REGIONS OF NOTHERN IDAHO AND WESTERN MONTANA. THE MEASURED FIRE EFFECTS WERE DIFFERENTIATED BY BURN SEVERITY ...

  4. State-space approach to evaluate spatial variability of field measured soil water status along a line transect in a volcanic-vesuvian soil

    Directory of Open Access Journals (Sweden)

    A. Comegna

    2010-12-01

    Full Text Available Unsaturated hydraulic properties and their spatial variability today are analyzed in order to use properly mathematical models developed to simulate flow of the water and solute movement at the field-scale soils. Many studies have shown that observations of soil hydraulic properties should not be considered purely random, given that they possess a structure which may be described by means of stochastic processes. The techniques used for analyzing such a structure have essentially been based either on the theory of regionalized variables or to a lesser extent, on the analysis of time series. This work attempts to use the time-series approach mentioned above by means of a study of pressure head h and water content θ which characterize soil water status, in the space-time domain. The data of the analyses were recorded in the open field during a controlled drainage process, evaporation being prevented, along a 50 m transect in a volcanic Vesuvian soil. The isotropic hypothesis is empirical proved and then the autocorrelation ACF and the partial autocorrelation functions PACF were used to identify and estimate the ARMA(1,1 statistical model for the analyzed series and the AR(1 for the extracted signal. Relations with a state-space model are investigated, and a bivariate AR(1 model fitted. The simultaneous relations between θ and h are considered and estimated. The results are of value for sampling strategies and they should incite to a larger use of time and space series analysis.

  5. Soils Developed from Different Volcanic Rocks from the Fernando de Noronha Island: Rare-Earth Element Patterns and Isotopic Lead Composition

    Directory of Open Access Journals (Sweden)

    Sonia Maria Barros de Oliveira

    2011-12-01

    Full Text Available This study examines the infl uence of pedogenesis on the distribution of rare earth elements in soils derived fromdifferent rock types and formed under tropical humid climate, as well as the possible contribution of airborne Pb to thesesoils. We studied 5 soil profi les developed from different volcanic rocks cropping out in the Fernando de Noronha island.Results show that in the course of weathering, the soils were enriched in REE. The REE patterns of the soils are similarto those of the parent material, except for a slight HREE enrichment. Lead-isotope data indicate the presence of a nonradiogenicanthropogenic component in the upper horizons of the soil profi les.

  6. Nitrogen transformations following tropical forest felling and burning on a volcanic soil

    Science.gov (United States)

    Matson, Pamela A.; Vitousek, Peter M.; Ewel, John J.; Mazzarino, Maria Julia; Robertson, G. Philip

    1987-01-01

    Nitrogen transformations and loss were measured following forest clearing in a relatively fertile tropical forest site. Nitrogen mineralization, nitrification, and amounts of ammonium and nitrate increased substantially in surface soils during the 6 mo following burning, then returned to background levels. The nitrogen content of microbial biomass declined to half its original value 6 mo after clearing and remained low in the cleared sites. Plant uptake of nitrogen was substantial on cleared plots (50 g/sq m), but it accounted for only 18 percent of N-15 label added to field plots. MIcrobial immobilization of N-15 was small relative to that in a cleared temperate site, and measurements of denitrification potentials suggested that relatively little mineralized nitrogen was lost to the atmosphere. Substantial amounts of nitrogen (40-70 g/sq m) were retained as exchangeably bound nitrate deep in the soils of a cleared plot on which revegetation was prevented; this process accounted for 12 percent of the N-15 label added to field plots.

  7. Late Pleistocene to Holocene soil development and environments in the Long Gang Volcanic Field area, Jilin Province, NE China

    Science.gov (United States)

    Sauer, Daniela; Zhang, Xinrong; Knöbel, Jette; Maerker, Lutz

    2014-05-01

    Late Pleistocene to Holocene shifts of climate and vegetation in the Long Gang Volcanic Field in NE China have been reconstructed, e. g. by Steblich et al. (2009), based on Maar lake sediment cores. In this study, we investigated soil development during the Late Pleistocene and Holocene and linked it to the climate and vegetation reported in the literature. Three pedons were described and analyzed on a crater wall surrounding a maar. The lower part of the slope is covered by basic pyroclastics that are obviously younger than the maar itself. Pedon 1 is located on the upper slope, where the younger pyroclastics are not present; thus it developed over the entire Holocene and part of the Late Pleistocene. Pedon 2 is on the toe slope and developed from the young basic pyroclastics. Vegetation remains, charred by fire that was caused by the volcanic ash fall, were found in the lowermost part of the pyroclastics layer, on top of a paleosol. Charcoal fragments were dated to 18950-18830 cal BP (using INTCAL 09). Thus, pedon 2 developed since around 18.9 ka BP, whereas the development of the paleosol that was buried under the pyroclastics (pedon 3), was stopped at this time. Pedons 1 and 2 are Vitric Andosols, developed mainly from basic pyroclastics, as evidenced by the composition of rock fragments in the soils, comprising 78 / 81 mass % lapilli and 22 / 19 mass % gneiss fragments, respectively. Pedon 3 is a Cutanic Luvisol (Chromic) that developed entirely from gneiss fragments produced by the maar explosion. Lab data suggest increasing intensity of pedogenesis in the direction: Pedon 3 (paleosol) < Pedon 2 < Pedon 1, reflected e. g. in increasing Fed/Fet ratios, decreasing molar ratios of (Ca+K+Na)/Al, and decreasing pH. However, it needs to be considered that lapilli are more readily weatherable than gneiss fragments. The profile morphology of the paleosol, characterized by reddish-brown color (7.5YR), strong angular blocky structure and well-expressed illuvial clay

  8. Ecosystem respiration, vegetation development and soil nitrogen in relation to breeding density of seagulls on a pristine volcanic island, Surtsey, Iceland

    Directory of Open Access Journals (Sweden)

    B. D. Sigurdsson

    2009-08-01

    Full Text Available Since its birth in 1963 by volcanic eruption in the North Atlantic Ocean off Iceland, Surtsey has been a unique natural laboratory on how organisms colonize volcanic islands and form ecosystems with contrasting structure and function. In July, 2004, ecosystem respiration rate, soil properties and surface cover of vascular plants were measured on 21 plots distributed among the main plant communities found 40 years after the primary succession started. The plots could be divided into two groups, inside and outside seagull (Larus sp. colonies found on the island. Vegetation cover of the plots was strongly related to the density of seagull nests within and around them. The occurrence of seagull nests and increased vegetation also coincided with significant increase in ecosystem respiration, soil carbon and nitrogen, and with significantly lower soil pH and soil temperatures. The ecosystem respiration was high inside the gull colonies, similar to the highest fluxes measured in drained wetlands or agricultural fields in Iceland. The most important factor for vegetation succession and ecosystem function on Surtsey seems to be the amount of nitrogen, which was mainly brought in by the seagulls.

  9. Application of Spectroscopic Techniques (FT-IR, 13C NMR) to the analysis of humic substances in volcanic soils along an environmental gradient (Tenerife, Canary Islands, Spain)

    Science.gov (United States)

    Rodriguez Rodriguez, Antonio; María Armas Herrera, Cecilia; González Pérez, José Antonio; González-Vila, Francisco Javier; Arbelo Rodríguez, Carmen Dolores; Mora Hernández, Juan Luis; Polvillo Polo, Oliva

    2010-05-01

    Andosols and andic soils are considered as efficient C-sinks in terms of C sequestration. These soils are usually developed from volcanic materials, and are characterized by a predominance of short-range ordered minerals like allophanes, imogolite and other Fe and Al oxyhydroxides. Such materials occur commonly associated with organic compounds, thus generating highly stable organo-mineral complexes and leading to the accumulation of a high amount of organic carbon. Spectroscopic methods like FT-IR and 13C NMR are suitable for the analysis of the chemical structure of soil humic substances, and allow identifying distinct functional groups and protein, lipids, lignin, carbohydrate-derived fragments. In this work we study the structural features of four soils developed on Pleistocene basaltic lavae in Tenerife (Canary Island, Spain), distributed along an altitudinal climatic gradient. The soil sequence comprises soils with different degree of geochemical evolution and andic character, including a mineral ‘Hypersalic Solonchak' (Tabaibal de Rasca), a slightly vitric ‘Luvic Phaeozem' (Los Frailes), a degraded and shallow ‘Endoleptic, fulvic, silandic Andosol' (Siete Lomas), and a well-developed and deep ‘Fulvic, silandic, Andosol' (Ravelo). Samples of the raw soil and humic and fulvic acids isolated from the surface horizons were analyzed. The results show a low content of organic carbon in the mineral soil, the inherited humin predominating, and a very high content of humic and fulvic acids in Andosols. The FT-IR and 13C NMR spectra of the raw soil samples show a low resolution, related to interferences from mineral complexes signals, particularly in soils with lower organic carbon content. 13C NMR shows a predominance of O-alkyl carbon (derived of carbohydrates) in andic soils, whereas O-alkyl and aromatic fractions are most evident in the mineral soil. The humic acids spectra are characterized by a dominance of alkyl and aromatic fractions with a high degree

  10. Spatial variability in depth and landscape of heavy metal contents of volcanic soils of the National Cajas Park in the Azuay Andes (Ecuador)

    Science.gov (United States)

    Bech, Jaume; Roca, Núria; Boluda, Rafael; Gil, Carlos; Ramos-Miras, Joaquín; Rodríguez, Jose A.

    2015-04-01

    Although the soils in the Azuay Andes are thought to be generally non-contaminated, it is necessary to preserve them from anthropogenic pollution. This area supplies drinking water to Cuenca, the third city of Ecuador. At present, very little information is available on baseline metal concentrations in Latin American soils. Therefore, it is important to establish the baseline of elements in soils as reference values for evaluating potential changes in their concentrations and to be able to define their origins. The objectives of this study are: (1) to show morphological, physical and chemical characteristics of Andisols in the Azuay Andes (Ecuador); (2) to determine the concentrations of six heavy metals (Cd, Cr, Cu, Ni, Pb and Zn) and (3) to evaluate the relationship between metal concentration and soil properties. The study area is located in National Cajas Park in the Paramo area of the Andes at Azuay Province (Ecuador). The geological origin of the National Cajas Park dates back to the Quaternary age. This area is a U-shaped glaciated valley formed over a pre-existing volcanic basement which consists of rhyolite and andesite volcanic tuff. The moraines are covered by discontinuous patches of volcanic ash. The climate is characterized by rather high rainfall, between 1200 to 2000 mm per year, regularly distributed and generally of a low intensity with a yearly average constant temperature (7°C) with high diurnal amplitudes. The paramo is a high altitude neotropical grassland ecosystem, located between the continuous forest border (~3500 m) and the eternal snow line (~5000 m). Seven representative volcanic soil pedons of a toposequence were studied and sampled. All horizons were analysed for physical and chemical properties by standard and specific methods for volcanic soils. Total metal concentrations in soil horizons were determined by ICP-MS spectrometer. The background values were calculated using the 4σ-outlier test. This requires the elimination of

  11. Hypoxia in Chilean Patagonian Fjords

    Science.gov (United States)

    Silva, Nelson; Vargas, Cristian A.

    2014-12-01

    Chilean Patagonia is one of the largest estuarine systems in the world. It is characterized by a complex geography of approximately 3300 islands, a total surface area of 240,000 km2, and 84,000 km of coast line, including islands, peninsulas, channels, fjords, and sounds. The Chilean Patagonia Interior Sea is filled with a mixture of sea, estuarine, and fresh waters, and is characterized by a two layer vertical general circulation. Dissolved oxygen (DO) conditions in these fjords were analyzed based on historic salinity, dissolved oxygen and nutrient data from 1200 oceanographic stations. Horizontal advection of adjacent well oxygenated Subantarctic Waters (5-6 mL L-1) was the mayor source of DO in the deep layers of the Interior Sea. Incoming DO was consumed by the respiration of autochthonous and allochthonous particulate organic matter, as ocean water flows towards the continental fjord heads, reaching near-hypoxic (2-3 mL L-1) or hypoxic levels (2 mL L-1) and four hypoxic (<2 mL L-1), but only at their heads. None were found to be anoxic (0 mL L-1). We found these DO conditions to be permanent features of the Chilean Patagonia Interior Sea.

  12. Catastrophic volcanism

    Science.gov (United States)

    Lipman, Peter W.

    1988-01-01

    Since primitive times, catastrophes due to volcanic activity have been vivid in the mind of man, who knew that his activities in many parts of the world were threatened by lava flows, mudflows, and ash falls. Within the present century, increasingly complex interactions between volcanism and the environment, on scales not previously experienced historically, have been detected or suspected from geologic observations. These include enormous hot pyroclastic flows associated with collapse at source calderas and fed by eruption columns that reached the stratosphere, relations between huge flood basalt eruptions at hotspots and the rifting of continents, devastating laterally-directed volcanic blasts and pyroclastic surges, great volcanic-generated tsunamis, climate modification from volcanic release of ash and sulfur aerosols into the upper atmosphere, modification of ocean circulation by volcanic constructs and attendent climatic implications, global pulsations in intensity of volcanic activity, and perhaps triggering of some intense terrestrial volcanism by planetary impacts. Complex feedback between volcanic activity and additional seemingly unrelated terrestrial processes likely remains unrecognized. Only recently has it become possible to begin to evaluate the degree to which such large-scale volcanic processes may have been important in triggering or modulating the tempo of faunal extinctions and other evolutionary events. In this overview, such processes are examined from the viewpoint of a field volcanologist, rather than as a previous participant in controversies concerning the interrelations between extinctions, impacts, and volcanism.

  13. Volcanic soils and landslides: a case study of the island of Ischia (southern Italy) and its relationship with other Campania events

    Science.gov (United States)

    Vingiani, S.; Mele, G.; De Mascellis, R.; Terribile, F.; Basile, A.

    2015-06-01

    An integrated investigation was carried out on the volcanic soils involved in the landslide phenomena that occurred in 2006 at Mt. Vezzi on the island of Ischia (southern Italy). Chemical (soil pH, organic carbon content, exchangeable cations and cation exchange capacity, electrical conductivity, Na adsorption ratio and Al, Fe and Si forms), physical (particle and pore size distribution, pore structure), hydrological (soil water retention, saturated and unsaturated hydraulic conductivity), mineralogical and micromorphological analyses were carried out for three soil profiles selected in two of the main head scarps. The studied soils showed a substantial abrupt discontinuity in all the studied properties at the interface with a buried fine ash layer (namely, the 2C horizon), that was only marginally involved in the sliding surface of the landslide phenomena. When compared to the overlying horizons, 2C showed (i) fine grey ash that is almost pumice free, with the silt content increasing by 20 %; (ii) ks values 1 order of magnitude lower; (iii) a pore distribution concentrated into small (15-30 μm modal class) pores characterised by a very low percolation threshold (approximately 15-25 μm); (iv) the presence of expandable clay minerals; and (v) increasing Na content in the exchange complex. Most of these properties indicated that 2C was a lower permeability horizon compared to the overlying ones. Nevertheless, it was possible to assume this interface to be an impeding layer to vertical water fluxes only by the identification of a thin (6.5 mm) finely stratified ash layer, on top of 2C, and of the hydromorphic features (e.g. Fe / Mn concretions) within and on top of the layer. Although Mt. Vezzi's soil environment has many properties in common with those of other Campania debris-mudflows (e.g. high gradient, north-facing slope, similar forestry, and volcanic origin of the parent material), the results of this study suggest a more complex relationship between soil

  14. Volcanic soils and landslides: the case study of the Ischia island (southern Italy) and relationship with other Campania events

    OpenAIRE

    S. Vingiani; G. Mele; R. De Mascellis; F. Terribile; Basile, A.

    2015-01-01

    An integrated investigation has been carried out over the soils involved in the landslide phenomena occurred in the 2006 at Mt. Vezzi in the Ischia island (southern Italy). Chemical, physical (i.e. particle size distribution, hydrological analyses and direct measurements of soil porosity), mineralogical and micromorphological properties of three soil profiles selected in two of the main detachment crowns were analysed. The studied soils, having a volcani...

  15. Aggregate structure and stability linked to carbon dynamics in a south Chilean Andisol

    OpenAIRE

    C. Oyarzún; Godoy, R.; O. Van Cleemput; P. Boeckx; Huygens, D.

    2005-01-01

    International audience The extreme vulnerability of soil organic carbon to climate and land use change emphasizes the need for further research in different terrestrial ecosystems. We have studied the aggregate stability and carbon dynamics in a chronosequence of three different land uses in a south Chilean Andisols: a second growth Nothofagus obliqua forest (SGFOR), a grassland (GRASS) and a Pinus radiata plantation (PINUS). The aim of this study was to investigate the role of Al as soil ...

  16. The influence of bioturbation on the vertical distribution of soil organic matter in volcanic ash soils: A case study in northern Ecuador

    OpenAIRE

    Tonneijck, F.H.; Jongmans, A.G.

    2008-01-01

    Soil faunal bioturbation ('bioturbation') is often cited as a major process influencing the vertical distribution of soil organic matter (SOM). The influence of bioturbation on vertical SOM transport is complex because it is the result of interaction between different groups of soil faunal species that redistribute SOM through the soil profile in distinct ways. We performed a semi-quantitative micromorphological analysis of soil faunal pedofeatures and related their occurrence to the vertical...

  17. Regulatory factors in crustacean zooplankton assemblages in mountain lakes of northern Chilean Patagonia (38-41°S): a comparison with Bulgarian counterparts (42°N) Factores reguladores en ensambles de crustáceos zooplanctónicos en lagos de montaña del norte de la Patagonia chilena (38-41°S): una comparación con sus contrapartes de Bulgaria (42°N)

    OpenAIRE

    Patricio De los Ríos-Escalante; Enrique Hauenstein; Patricio Acevedo; Mario Romero-Miéres; Ivan Pandourski

    2012-01-01

    Chilean Patagonia has protected mountainous areas with evergreen native forests; in which the lakes and rivers, of volcanic or glacial origin, are oligotrophic. In Bulgaria, there are mountainous zones with native forests and associated lakes of volcanic origin. The aim of the present study is to carry out a preliminary comparison of zooplanktonic crustaceans in lake ecosystems associated with native forests of Chilean Patagonia and of Bulgarian mountains. The study revealed that the lakes st...

  18. NaOH and Na4P2O7 extractable organic matter in two allophanic volcanic ash soils of the Azores Islands : a pyrolysis GC/MC study

    NARCIS (Netherlands)

    Nierop, K.G.J.; Bergen, van P.F.; Buurman, P.; Lagen, van B.

    2005-01-01

    NaOH and Na4P2O7 extractable organic matter fractions of two volcanic ash profiles (Azores Islands) were studied by pyrolysis gas chromatography/mass spectrometry (Py-GC/MS). The soils did not have melanic horizons and were not affected by burning. The pyrolysates of all samples were dominated by po

  19. Assessment of organic matter resistance to biodegradation in volcanic ash soils assisted by automated interpretation of infrared spectra from humic acid and whole soil samples by using partial least squares

    Science.gov (United States)

    Hernández, Zulimar; Pérez Trujillo, Juan Pedro; Hernández-Hernández, Sergio Alexander; Almendros, Gonzalo; Sanz, Jesús

    2014-05-01

    From a practical viewpoint, the most interesting possibilities of applying infrared (IR) spectroscopy to soil studies lie on processing IR spectra of whole soil (WS) samples [1] in order to forecast functional descriptors at high organizational levels of the soil system, such as soil C resilience. Currently, there is a discussion on whether the resistance to biodegradation of soil organic matter (SOM) depends on its molecular composition or on environmental interactions between SOM and mineral components, such could be the case with physical encapsulation of particulate SOM or organo-mineral derivatives, e.g., those formed with amorphous oxides [2]. A set of about 200 dependent variables from WS and isolated, ash free, humic acids (HA) [3] was obtained in 30 volcanic ash soils from Tenerife Island (Spain). Soil biogeochemical properties such as SOM, allophane (Alo + 1 /2 Feo), total mineralization coefficient (TMC) or aggregate stability were determined in WS. In addition, structural information on SOM was obtained from the isolated HA fractions by visible spectroscopy and analytical pyrolysis (Py-GC/MS). Aiming to explore the potential of partial least squares regression (PLS) in forecasting soil dependent variables, exclusively using the information extracted from WS and HA IR spectral profiles, data were processed by using ParLeS [4] and Unscrambler programs. Data pre-treatments should be carefully chosen: the most significant PLS models from IR spectra of HA were obtained after second derivative pre-treatment, which prevented effects of intrinsically broadband spectral profiles typical in macromolecular heterogeneous material such as HA. Conversely, when using IR spectra of WS, the best forecasting models were obtained using linear baseline correction and maximum normalization pre-treatment. With WS spectra, the most successful prediction models were obtained for SOM, magnetite, allophane, aggregate stability, clay and total aromatic compounds, whereas the PLS

  20. Specific activities of natural rocks and soils at quaternary intraplate volcanism north of Sana'a, Yemen

    International Nuclear Information System (INIS)

    The level of natural radioactivity in rocks and soil of 32 samples collected from locations at North Sana'a in Yemen was measured. Concentrations of radionuclides in rocks and soils samples were determined by gamma-ray spectrometer using high purity germanium (HPGe) detector with specially designed shield. The average radioactivity concentrations of 226Ra, 232Th, 40K were determined and expressed in Bq/kg. The results showed that these radionuclides were present in concentrations of 21.79 ± 3.1, 19.5 ± 2.6 and 399.3 ± 16 Bq/kg, respectively, for rocks. For soil, the corresponding values were 48.2 ± 4.4, 41.7 ± 4.5 and 939.1 ± 36 Bq/kg, respectively. Also, the radiological hazard of the natural radionuclide content, radium equivalent activity, total dose rates, external hazard index and gamma activity concentration index of the (rocks/soils) samples in the area under consideration were calculated. The dose rates at 1 m above the ground from terrestrial sources were 38.39 and 86.89 nGy/h for rocks and surface soil, respectively, which present no significant health hazards to humans. (author)

  1. Archaeal ammonia oxidation in volcanic grassland soils of Iceland. Effects of elevated temperature and N availability on processes and organisms

    NARCIS (Netherlands)

    Daebeler, A.

    2014-01-01

    Thaumarchaea are recognized today as the most abundant and ubiquitously dis­tributed archaeal organisms, especially in the oceans and soil. Their phylogenetic placement as a phylum, the capability of all cultivated Thaumarchaea to oxidize ammonia for energy conservation as well as many further aspec

  2. Erosion Rates of Volcanic-ash Derived Soils in the Blue Mountains of Eastern Oregon, USA: A Comparison Across Sales in Space and Time.

    Science.gov (United States)

    Wondzell, S. M.; Clifton, C. F.; Harris, R. M.; Ritchie, J. C.

    2007-12-01

    We examined present day rates of erosion in the Blue Mountains of eastern Oregon to quantify background erosion rates to provide standards for assessing possible accelerated rates of erosion resulting from wild fire or from land-management activities such as prescribed fire. The Skookum Creek watersheds, where stream discharge and sediment yield have been recorded continuously since the watersheds were gauged in 1992, provided a watershed-scale estimate of erosion rates. We installed hillslope erosion plots on north- and south- facing slopes within the watersheds in 2002 and collected data for three years to estimate short-term, hillslope- scale erosion rates. We also collected soil samples and analyzed them for 137Cs to get a 40-yr time- integrated estimate of hillslope erosion rates. Our results showed large differences between whole-watershed sediment yields and hillslope erosion rates measured from plots, suggesting that episodic processes dominated sediment production and transport and therefore controlled watershed-scale sediment budgets. At the hillslope-scale, short-term erosion resulted primarily from digging by small mammals and trampling by elk. Visual observations at the plots suggested that annual down-slope sediment movement was usually less than one meter. There were no significant difference among slope positions, but erosion rates were significantly higher on south-facing aspects and positively correlated to the amount of bare ground. In contrast, the 137Cs data suggested that erosion rates differed with slope position. Higher erosion rates were measured in toe- and mid-slope positions, with little erosion occurring on upper slopes and ridge tops. We examine these results in light of the present-day pattern of surface soils resulting from redistribution of volcanic ash from upper- slope to lower-slope positions and the effects of disturbance, including wildfire and the preferential grazing of riparian and lower-slope positions by domestic livestock.

  3. Fostering Teaching Quality in Chilean Universities

    Science.gov (United States)

    Guzman Cruzat, Jose Antonio

    2013-01-01

    This study aims to explain the strategies that have been carried out by three Chilean universities in order to advance the quality of their teaching. The studied institutions are the Universidad de los Andes, the Universidad de Talca and the Universidad Catolica de Chile. In each of these three cases the analysis included, both the policies…

  4. The CHilean Automatic Supernova sEarch

    DEFF Research Database (Denmark)

    Hamuy, M.; Pignata, G.; Maza, J.;

    2012-01-01

    The CHilean Automatic Supernova sEarch (CHASE) project began in 2007 with the goal to discover young, nearby southern supernovae in order to (1) better understand the physics of exploding stars and their progenitors, and (2) refine the methods to derive extragalactic distances. During the first...

  5. Examining Text Environments in Elementary Chilean Classrooms

    Science.gov (United States)

    Orellana-Garcia, Pelusa; Sailors, Misty

    2016-01-01

    In this study, we examine the social practices related to literacy in classrooms in Chile in order to examine school-based literacy practices. We also examined the constraints and affordances literacy learning offered Chilean students. Through our case study and cross-case analysis, we discovered that although the classrooms contained an…

  6. Exploring a long-lasting volcanic eruption by means of in-soil radon measurements and seismic activity

    Science.gov (United States)

    Falsaperla, Susanna; Neri, Marco; Di Grazia, Giuseppe; Langer, Horst; Spampinato, Salvatore

    2016-04-01

    We analyze in-soil radon (Rn) emission and ambient parameters (barometric pressure and air temperature measurements) along with seismic activity during the longest flank eruption of this century at Mt. Etna, Italy. This eruption occurred between 14 May 2008 and 6 July 2009, from a N120-140°E eruptive fissure extending between 3050 and 2620 m above sea level. It was heralded by a short-lived (~5 hours) episode of lava fountaining three days before a dike-forming intrusion fed a lava emission, which affected the summit area of the volcano over ~15 months. The peculiar position of the station for the Rn measurement, which was at an altitude of 2950 m above sea level and near (~1 km) the summit active craters, offered us the uncommon chance: i) to explore the temporal development of the gas emission close (SUV) project.

  7. Urea Fertilizer and pH Influence on Sorption Process of Flumetsulam and MCPA Acidic Herbicides in a Volcanic Soil.

    Science.gov (United States)

    Palma, Graciela; Jorquera, Milko; Demanet, Rolando; Elgueta, Sebastian; Briceño, Gabriela; de la Luz Mora, María

    2016-01-01

    The aim of this study was to evaluate the influence of urea fertilizer and pH on the sorption process of two acidic herbicides, flumetsulam (2',6'-difluoro-5-methyl[1,2,4]triazolo[1,5-a]pyrimidine-2-sulfonanilide) and MCPA (4-chloro--tolyloxyacetic acid), on an Andisol. Urea reduced the adsorption of MCPA but not that of flumetsulam. The Freundlich parameter of MCPA decreased from 8.5 to 5.1 mg L kg. This finding could be attributed to an increase in dissolved organic C due to an initial increase in soil pH for urea application. The higher acidic character of MCPA compared with that of flumetsulam produced a greater hydrolysis of urea, leading to a further pH increase. A marked effect of pH on the adsorption of both herbicides was observed. The organic C distribution coefficient () values for flumetsulam were in the range of 74 to 10 L kg, while those of MCPA were in the range of 208 to 45 L kg. In the kinetic studies, the pseudo-second-order model appeared to fit the data best ( > 0.994). The initial adsorption rates () ranged from 20.00 to 4.59 mg kg h for flumetsulam and from 125.00 to 25.60 mg kg hfor MCPA. Both herbicides were adsorbed rapidly during the first stage of the sorption process, and the rates of sorption were dependent on pH. The application of the Elovich and Weber-Morris models led us to conclude that mass transfer through the boundary layer and, to a lesser degree, intraparticle diffusion were influenced by the chemical character of the herbicide. These results suggest that urea application could increase leaching of acid herbicides in soils. PMID:26828188

  8. Urea Fertilizer and pH Influence on Sorption Process of Flumetsulam and MCPA Acidic Herbicides in a Volcanic Soil.

    Science.gov (United States)

    Palma, Graciela; Jorquera, Milko; Demanet, Rolando; Elgueta, Sebastian; Briceño, Gabriela; de la Luz Mora, María

    2016-01-01

    The aim of this study was to evaluate the influence of urea fertilizer and pH on the sorption process of two acidic herbicides, flumetsulam (2',6'-difluoro-5-methyl[1,2,4]triazolo[1,5-a]pyrimidine-2-sulfonanilide) and MCPA (4-chloro--tolyloxyacetic acid), on an Andisol. Urea reduced the adsorption of MCPA but not that of flumetsulam. The Freundlich parameter of MCPA decreased from 8.5 to 5.1 mg L kg. This finding could be attributed to an increase in dissolved organic C due to an initial increase in soil pH for urea application. The higher acidic character of MCPA compared with that of flumetsulam produced a greater hydrolysis of urea, leading to a further pH increase. A marked effect of pH on the adsorption of both herbicides was observed. The organic C distribution coefficient () values for flumetsulam were in the range of 74 to 10 L kg, while those of MCPA were in the range of 208 to 45 L kg. In the kinetic studies, the pseudo-second-order model appeared to fit the data best ( > 0.994). The initial adsorption rates () ranged from 20.00 to 4.59 mg kg h for flumetsulam and from 125.00 to 25.60 mg kg hfor MCPA. Both herbicides were adsorbed rapidly during the first stage of the sorption process, and the rates of sorption were dependent on pH. The application of the Elovich and Weber-Morris models led us to conclude that mass transfer through the boundary layer and, to a lesser degree, intraparticle diffusion were influenced by the chemical character of the herbicide. These results suggest that urea application could increase leaching of acid herbicides in soils.

  9. Effect of nitrogen and phosphorus fertilization on the composition of rhizobacterial communities of two Chilean Andisol pastures.

    Science.gov (United States)

    Jorquera, Milko A; Martínez, Oscar A; Marileo, Luis G; Acuña, Jacquelinne J; Saggar, Surinder; Mora, María L

    2014-01-01

    The effect of nitrogen (N) and phosphorus (P) fertilization on composition of rhizobacterial communities of volcanic soils (Andisols) from southern Chile at molecular level is poorly understood. This paper investigates the composition of rhizobacterial communities of two Andisols under pasture after 1- and 6-year applications of N (urea) and P (triple superphosphate). Soil samples were collected from two previously established sites and the composition of rhizobacterial communities was determined by denaturing gradient gel electrophoresis (PCR-DGGE). The difference in the composition and diversity between rhizobacterial communities was assessed by nonmetric multidimensional scaling (MDS) analysis and the Shannon-Wiener index. In Site 1 (fertilized for 1 year), PCR-DGGE targeting 16S rRNA genes and MDS analysis showed that moderate N application (270 kg N ha(-1) year(-1)) without P significantly changed the composition of rhizobacterial communities. However, no significant community changes were observed with P (240 kg P ha(-1) year(-1)) and N-P application (270 kg N ha(-1) year(-1) plus 240 kg P ha(-1) year(-1)). In Site 2 (fertilized for 6 years with P; 400 kg P ha(-1) year(-1)), PCR-DGGE targeting rpoB, nifH, amoA and alkaline phosphatase genes and MDS analysis showed changes in rhizobacterial communities only at the highest rate of N application (600 kg N ha(-1) year(-1)). Quantitative PCR targeting 16S rRNA genes also showed higher abundance of bacteria at higher N application. In samples from both sites, the Shannon-Wiener index did not show significant difference in the diversity of rhizobacterial communities. The changes observed in rhizobacterial communities coincide in N fertilized pastures with lower soil pH and higher pasture yields. This study indicates that N-P application affects the soil bacterial populations at molecular level and needs to be considered when developing fertilizer practices for Chilean pastoral Andisols. PMID

  10. Innovation Performance of Chilean SMEs: A Bivariate Probit Analysis

    OpenAIRE

    Rehman, Naqeeb Ur

    2016-01-01

    The purpose of this paper is to investigate the innovation activities of Chilean firms’ by using micro level data. Previous studies showed research gap related to micro level analysis of the Chilean SMEs. For the first time, multiple proxies have been used as dependent variables (product/process innovations and patent application/spending), which is neglected by the past studies. A micro level data has been obtained from the World Bank, Enterprise Survey on 696 Chilean SMEs. Bivariate probit...

  11. Adsorption of glyphosate in chilean soils and its relationship with unoccupied phosphate binding sites Adsorção de glifosato em solos chilenos e sua relação com sítios de adsorção disponíveis para adsorção de fosfato

    Directory of Open Access Journals (Sweden)

    Marcelo Kogan

    2003-04-01

    Full Text Available The objective of this work was to investigate glyphosate adsorption by soils and its relationship with unoccupied binding sites for phosphate adsorption. Soil samples of three Chilean soils series - Valdivia (Andisol, Clarillo (Inceptisol and Chicureo (Vertisol - were incubated with different herbicide concentrations. Glyphosate remaining in solution was determined by adjusting a HPLC method with a UV detector. Experimental maximum adsorption capacity were 15,000, 14,300 and 4,700 mg g¹ for Valdivia, Clarillo, and Chicureo soils, respectively. Linear, Freundlich, and Langmuir models were used to describe glyphosate adsorption. Isotherms describing glyphosate adsorption differed among soils. Maximum adjusted adsorption capacity with the Langmuir model was 231,884, 17,874 and 5,670 mg g-1 for Valdivia, Clarillo, and Chicureo soils, respectively. Glyphosate adsorption on the Valdivia soil showed a linear behavior at the range of concentrations used and none of the adjusted models became asymptotic. The high glyphosate adsorption capacity of the Valdivia soil was probably a result of its high exchangeable Al, extractable Fe, and alophan and imogolite clay type. Adsorption was very much related to phosphate dynamics in the Valdivia soil, which showed the larger unoccupied phosphate binding sites. However relationship between unoccupied phosphate binding sites and glyphosate adsorption in the other two soils (Clarillo and Chicureo was not clear.O objetivo deste trabalho foi investigar a adsorção de glifosato em solos e sua relação com os sítios disponíveis para adsorção de fosfato. Amostras de três solos chilenos - Valdivia (Andisol, Clarillo (Inceptisol e Chicureo (Vertisol - foram incubadas com diferentes concentrações do herbicida. O glifosato remanescente na solução foi determinado pelo método de HPLC com detector de UV modificado. A capacidade de adsorção máxima experimental foi de 15.000, 14.300 e 4.700 mg g-1 para os solos de

  12. Constructing Realities: Bullying Usages in Chilean Discourses

    Directory of Open Access Journals (Sweden)

    Rodrigo Bassaletti-Contreras

    2013-07-01

    Full Text Available The article reports an exploratory research on the uses given in Chile to the Anglicism bullying. In order to do so, its evolution is reviewed from the early studies in the Nordic countries, to the treatment of the topic in the Chilean context. The focus of this work is based on socioconstructionism and in turn promotes the consideration of the characteristics of the socio-cultural and historical context of knowledge production with a postcolonial intention. To review the constructions on the subject, we selected Chilean videos at the YouTube virtual platform, using as methodology discourse analysis and dense description. In results can be observed two meanings of bullying: (i to refer to any kind of aggression and (ii as a homologous of abuse among schoolchildren. In response, it is realized the discrepancy with the proposed definitions from general academia and those used in the local environment in investigations, interventions, public policy and mass media in Chile.

  13. Organizational and territorial cultures in Chilean journalism

    OpenAIRE

    Claudia Mellado; Claudia Lagos

    2011-01-01

    On the basis of survey responses of 570 journalists from 114 newspapers, radio, newswires, television, and internet news organizations, this paper describes the role conceptions, epistemological underpinning, and ethical values of the Chilean news media workers, comparing the differences that exist among media types and between the capital and the rest of the country. The findings show territorial cultures of journalism, with differences between the capital and provincial regions, mostly clas...

  14. Memorial 1997 - ENDESA (Chilean Electricity Company)

    International Nuclear Information System (INIS)

    This report provides a comprehensive survey, in depth assessment of the activities overview of ENDESA, Chilean Electricity Company, highlighting economical information and including historical and technical aspects. Economics is its focal point, but other relevant data are shown, like technical data on hydroelectric and thermoelectric power plants. Main activities developed by ENDESA are described, such in Chile as in the foreign. Data on power generation, transmission and transport are also presented and an economical balance of each colligated company are done and analysed

  15. A BVAR Forecasting Model for the Chilean Economy A BVAR Forecasting Model for the Chilean Economy

    Directory of Open Access Journals (Sweden)

    Felipe Morandé

    1988-03-01

    Full Text Available A BVAR Forecasting Model for the Chilean Economy Doan, Litterman, and Sims have described a method for estimaling Bayesian vector autoregressive (BVAR forecasting models. The method has been successfully applied to the U.S. macroeconomic dataset, which is relatively long and stable. Despite the brevity and volatily of the post-1976 Chilean macroeconomic dataset, this paper shows that a straightforward application of the DLS method to this datasef, with simple modification to allow for delays in the release of data, also appears to satisfy at least one criterion of relative forecasting accuracy suggested by Doan, Litterman, and Sims. However, the forecast errors of the Chilean BVARs are stil large in absolute term. Also, the model's coefficients change sharply in periods marked by policy shifts, such as the floating of the peso in 1982.

  16. Aggregate structure and stability linked to carbon dynamics in a south Chilean Andisol

    Directory of Open Access Journals (Sweden)

    C. Oyarzún

    2005-02-01

    Full Text Available The extreme vulnerability of soil organic carbon to climate and land use change emphasizes the need for further research in different terrestrial ecosystems. We have studied the aggregate stability and carbon dynamics in a chronosequence of three different land uses in a south Chilean Andisols: a second growth Nothofagus obliqua forest (SGFOR, a grassland (GRASS and a Pinus radiata plantation (PINUS. The aim of this study was to investigate the role of Al as soil organic matter stabilizing agent in this Andisol. In a case study, we linked differences in carbon dynamics between the three land use treatments to physical protection and recalcitrance of the soil organic matter (SOM. In this study, C aggregate stability and dynamics were studied using size and density fractionation experiments of the SOM, δ13C and total carbon analysis of the different SOM fractions, and mineralization measurements. The results showed that electrostatic attractions between and among Al-oxides and clay minerals are mainly responsible for the stabilization of soil aggregates and the physical protection of the enclosed soil organic carbon. Whole soil C mineralization rate constants were highest for SGFOR and PINUS, followed by GRASS. In contrast, incubation experiments of isolated macro organic matter fractions showed that the recalcitrance of the SOM decreased in another order: PINUS > SGFOR > GRASS. We concluded that physical protection of soil aggregates was the main process determining whole soil C mineralization. Land use changes affected soil organic carbon dynamics in this south Chilean Andisol by altering soil pH and consequently available Al.

  17. Soil properties influencing phytoparasitic nematode population on Chilean vineyards Propiedades del suelo que influyen en la población de nematodos fitoparásitos en viñedos de Chile

    Directory of Open Access Journals (Sweden)

    Mario Fajardo P

    2011-06-01

    Full Text Available Lifecycle of phytoparasitic nematode takes place in the rhizosphere, therefore their breeding, parasitism and mobility dynamics are inevitably influenced by the soil-root interaction, A study was performed to evaluate the influence of Vitis rootstocks to some plant parasitic nematodes under different soil conditions. Nematode populations were assessed in Vitis vinifera L. var ‘Chardonnay’ plants grafted on two rootstocks (K5BB, SO4 and ungrafted ‘Chardonnay’ as a control in three diferent alluvial soils in the central zone of Chile. Soils were two Inceptisols of the Casablanca Valley (Valparaíso Region, the first one without soil structure and with a densification zone in depth (S1 and the second one with sandy textural class (S3. A third soil was a Mollisol (S2 more structured than the others, situated on a locality of Melipilla (Metropolitan Region. The soils were characterized physically and morphologically and nematode genera were identified and counted using a dissecting microscope. ‘Chardonnay’ presented the highest population of Meloidogyne spp. on the three soil conditions but only significant in S2 soil. The population of Xiphinema spp. and Mesocriconema xenoplax were not representative enough to relate them with either soil or the different rootstocks. The amount of Meloidogyne spp. was inversely related with the sand content but positively related with the more structured soil. The stepwise regressions resulted useful when relating nematode populations with multiple soil factors.El ciclo de vida de los nematodos fitoparásitos ocurre en la rizósfera, por lo tanto, sus dinámicas de alimentación, parasitismo y movilidad están inevitablemente influenciadas por la interacción suelo-raíz. Se llevó a cabo un estudio para evaluar la respuesta de diferentes portainjertos de Vitis frente a algunas poblaciones de nematodos fitoparásitos en diferentes tipos de suelos. Se determinaron las poblaciones de nematodos fitopar

  18. Rhizobacterial Community Structures Associated with Native Plants Grown in Chilean Extreme Environments.

    Science.gov (United States)

    Jorquera, Milko A; Maruyama, Fumito; Ogram, Andrew V; Navarrete, Oscar U; Lagos, Lorena M; Inostroza, Nitza G; Acuña, Jacquelinne J; Rilling, Joaquín I; de La Luz Mora, María

    2016-10-01

    Chile is topographically and climatically diverse, with a wide array of diverse undisturbed ecosystems that include native plants that are highly adapted to local conditions. However, our understanding of the diversity, activity, and role of rhizobacteria associated with natural vegetation in undisturbed Chilean extreme ecosystems is very poor. In the present study, the combination of denaturing gradient gel electrophoresis and 454-pyrosequencing approaches was used to describe the rhizobacterial community structures of native plants grown in three representative Chilean extreme environments: Atacama Desert (ATA), Andes Mountains (AND), and Antarctic (ANT). Both molecular approaches revealed the presence of Proteobacteria, Bacteroidetes, and Actinobacteria as the dominant phyla in the rhizospheres of native plants. Lower numbers of operational taxonomic units (OTUs) were observed in rhizosphere soils from ATA compared with AND and ANT. Both approaches also showed differences in rhizobacterial community structures between extreme environments and between plant species. The differences among plant species grown in the same environment were attributed to the higher relative abundance of classes Gammaproteobacteria and Alphaproteobacteria. However, further studies are needed to determine which environmental factors regulate the structures of rhizobacterial communities, and how (or if) specific bacterial groups may contribute to the growth and survival of native plants in each Chilean extreme environments. PMID:27406732

  19. Some Thoughts on the Evaluation of the Chilean Voucher System

    Science.gov (United States)

    Sapelli, Claudio

    2010-01-01

    Many papers describe the Chilean voucher system as the "textbook" voucher case. But this is mistaken and has prevented research to undertake the key question of how the particular design of the Chilean voucher system determines the results obtained in Chile. This also prevents discussion of how a voucher system with a different design could lead…

  20. Synopsis of volcanic stratigraphy

    Science.gov (United States)

    Hammond, P. E.

    1974-01-01

    Volcanic stratigraphic units are mappable layered units composed of volcanic rocks that are formed on land (subaerially) or under water (subaqueously) by volcanic processes. At least ten different types of volcanic stratigraphic units are recognized. The characteristics for each are discussed briefly and some typical examples are illustrated by diagrams to show their salient features.

  1. Are Chileans exposed to dietary furan?

    Science.gov (United States)

    Mariotti, María S; Toledo, Carla; Hevia, Karen; Gomez, J Pablo; Fromberg, Arvid; Granby, Kit; Rosowski, Jaime; Castillo, Oscar; Pedreschi, Franco

    2013-01-01

    Chilean consumer preferences include foods that may contain considerable amounts of furan, a potential human carcinogen. However, there is no information regarding dietary exposure to furan in Chile. Thus, the objective of this work was to determine the Chilean exposure to dietary furan. To accomplish this objective, the furan concentration of 14 types of commercial foods processed at high temperature were analysed based on a modified headspace-GC/MS (HS-GC/MS) method in which the limits of detection for different food matrices ranged from 0.01 to 0.6 ng g(-1). In addition, a risk assessment was made with exposure estimates based on dietary data from national studies on different age groups (9-month-old babies, school children, adults and elderly people). Of the food items surveyed "American"-type coffee (espresso coffee plus hot water) obtained from automatic coffee machine (936 ng g(-1)) and low moisture starchy products like crisps and "soda"-type crackers showed the highest furan concentrations (259 and 91 ng g(-1), respectively). Furthermore, furan was also found in samples of breakfast cereals (approximately 20 ng g(-1)), jarred fruit baby foods (8.5 ng g(-1)) and orange juice (7.0 ng g(-1)). School children (aged 9-13 years) represented the highest intake of furan (about 500 ng kg(-1)(bw) day(-1)), with margins of exposure of 2479 and 2411, respectively, which points to a possible public health risk. PMID:23875686

  2. Mineral and geochemical characterization of a leptic aluandic soil and a thapto aluandic-ferralsol developed on trachytes in Mount Bambouto (Cameroon volcanic line)

    OpenAIRE

    Tematio, P.; Fritsch, Emmanuel; Hodson, M E; LUCAS, Y.; Bitom, D.; Bilong, P.

    2009-01-01

    Mineral and geochemical investigations were carried out on soil samples and fresh rock (trachytes) from two selected soil profiles (TM profile on leptic aluandic soils and TL profile on thapto aluandic-ferralsols) from Mount Bambouto to better understand geochemical processes and mineral paragenesis involved in the development of soils in this environment. In TM profile, the hydrated halloysites and goethite occur in the weathered saprolite boulders of BC horizon while dehydrated halloysite, ...

  3. Chemical properties of volcanic soil affected by seven-year rotations Propiedades químicas del suelo volcánico afectado por rotaciones de siete años

    Directory of Open Access Journals (Sweden)

    Juan Hirzel

    2011-06-01

    Full Text Available Long-term crop rotation systems can benefit soil chemical-physical properties and crop productivity. The lack of information on the effect of long-term crop rotations on soil chemical-physical properties for volcanic soils in Chile could restrict reaping real benefits, and make it difficult to take agricultural management decisions, which could lead to possible negative consequences on some soil chemical-physical properties and the environment. The development of information associated with the effect on soil chemical-physical properties with respect to long-term rotation systems and their fertilization management contribute to improving agronomic management decisions for these soils. A study was carried out to assess the effect of six rotation systems replicating fertilization management used by farmers, especially N and P application, and eventually low rates of K, Ca and Mg on soil chemical properties in a volcanic soil after 7 yr in Central South Chile. Affected chemical properties were pH, inorganic N, and available K, along with a general decrease of pH related to fertilization used, which was insufficient in Ca, K, and Mg. Moreover, this soil exhibited high P adsorption capacity (90.2 to 97.5%. Hence, crop rotations that included pasture legumes and crops with high nutrient inputs such as sugar beet (Beta vulgaris L. generated a less negative effect on soil chemical properties. This study indicates that fertilization management in crop rotation systems must consider the input and output nutrient balances to prevent the negative effect on some soil chemical properties.Los sistemas de rotación de cultivos de largo plazo pueden tener varios beneficios sobre las propiedades físico-químicas del suelo y productividad de los cultivos. La falta de información sobre el efecto de rotaciones de largo plazo en las propiedades físico-químicas para suelos volcánicos en Chile podría limitar la obtención de beneficios reales, dificultando

  4. Simplicity of the Tax Systems: The Chilean Case. (in Spanish)

    OpenAIRE

    Barra, Patricio

    2006-01-01

    The objective of this paper is to evaluate the concept of the simplicity in a tax system. The analysis approaches the different scopes in which the tax simplicity is observed. For this purpose, the main aspects of the Chilean tax system are analyzed, by using indicators that try to define the concept in a quantitative frame. The analysis of the Chilean case is used to infer some implications that could also be valid in other Latin American tax systems.

  5. Nutrition education in Chilean primary schools.

    Science.gov (United States)

    Olivares, Sonia; Zacarías, Isabel; Andrade, Margarita; Kain, Juliana; Lera, Lydia; Vio, Fernando; Morón, Cecilio

    2005-06-01

    The purpose of this study was to incorporate nutrition education in Chilean primary schools. The baseline information included nutritional status, food consumption and physical activity of 1701 children from 3rd to 7th grade in ten urban and rural schools. Main results showed a high prevalence of obesity (15.4%) and overweight (19.6%), low consumption of vegetables, fruits, and dairy products, high intake of snacks and a low level of physical activity, especially in girls. Because the Ministry of Education does not allow the incorporation of new programs into the curriculum, the educational strategy was based on the development of a text book, a teacher's guide, five practical guides for students from third to eighth grade and a CD-Rom. These materials were validated by 36 teachers in six schools through an educational intervention. Teachers and students considered the educational materials useful, motivational and easy to understand. This program is being implemented in 57 schools.

  6. Dynamic carbon content as an indicator of desertification processes in soils developed from volcanic parental material in the Region of Murcia; Contenido en carbono organico como indicador del proceso de desertificacion en suelos desarrollados en material parental volcanico en la Region de Murcia

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-Martinez, S.; Faz Cano, A.; Acosta Aviles, J. A.

    2009-07-01

    Soil Organic Carbon (SOC is an essential components of the global carbon cycle, especially in soils developed from volcanic rocks, due to these soils does not have inorganic carbon. In arid and semiarid areas mineralization of organic carbon is very intense due to climatic conditions, causing soils depletion and therefore desertification. The objective of this study is to determine the content of OC, as a first step in the assessment of desertification. The objective of this study is to determine the content of OC, as a first step in the assessment of desertification processes affecting this area of the southeast of Spain. (Author) 7 refs.

  7. Definition of a mobilizing volume of sediment in a valley interested by volcanic eruption: Rio Blanco valley (Chile)

    Science.gov (United States)

    Oss-Cazzador, Daniele; Iroumé, Andrés; Picco, Lorenzo

    2016-04-01

    Volcanic explosive activity can strongly affect the riverine environments. Deposition of tephra, pyroclastic and hyperconcentrated flows along both the valley bottom and hillslopes can radically change the environmental morphology. Accumulation and transport of pyroclastic material can increase hazards and risks for anthropic activities. The aims of this research are to evaluate and quantify the amount of erodible sediment that can be transported along a gravel bed river affected by a volcanic eruption. The Rio Blanco valley (Chile) was upset by the plinian-type eruption of Chaiten volcano in 2008. The great amount of tephra released in the initial phase and the subsequent pyroclastic flows, accumulated up to 8 m of sediment over a great portion of the Rio Blanco valley. Using aerial photographs was possible to define the extension of vegetated zones affected by the eruption. The area was interested by a high mortality of vegetation, as confirmed by field surveys. Dendrometric measurements permitted to quantify the volume of wood and observe that renewal and herbal layer are almost absent, determining low soil cohesion and easier erosion by superficial and river erosion processes. Analysis of sediment accumulation allowed quantifying the volume of sediment that can be transported downstream. The analyses were carried out considering 7 km-long a reach, from the river mouth to the confluence between Caldera creek and Rio Blanco. After the eruption, was possible to define as a total area of about 2.19 km2 was affected by tephra deposition, the 40% (0,87 km2) was eroded by flows, while 60% (1,32 km2) is still present and composed by tephra, buried large wood (LW) and dead standing trees. Considering an average high of 5 m, the potential erodible sediment is around 6,5 x 106 m3, moreover there is a potential amount of about 7,3 x 104 m3 of LW that can be transported towards mouth. These analyses can be useful to better define the management plan for the river delta. In

  8. Geochemical evidence for African dust and volcanic ash inputs to terra rossa soils on carbonate reef terraces, northern Jamaica, West Indies

    Science.gov (United States)

    Muhs, D.R.; Budahn, J.R.

    2009-01-01

    The origin of red or reddish-brown, clay-rich, "terra rossa" soils on limestone has been debated for decades. A traditional qualitative explanation for their formation has been the accumulation of insoluble residues as the limestone is progressively dissolved over time. However, this mode of formation often requires unrealistic or impossible amounts of carbonate dissolution. Therefore, where this mechanism is not viable and where local fluvial or colluvial inputs can be ruled out, an external source or sources must be involved in soil formation. On the north coast of the Caribbean island of Jamaica, we studied a sequence of terra rossa soils developed on emergent limestones thought to be of Quaternary age. The soils become progressively thicker, redder, more Fe- and Al-rich and Si-poor with elevation. Furthermore, although kaolinite is found in all the soils, the highest and oldest soils also contain boehmite. Major and trace element geochemistry shows that the host limestones and local igneous rocks are not likely source materials for the soils. Other trace elements, including the rare earth elements (REE), show that tephra from Central American volcanoes is not a likely source either. However, trace element geochemistry shows that airborne dust from Africa plus tephra from the Lesser Antilles island arc are possible source materials for the clay-rich soils. A third, as yet unidentified, source may also contribute to the soils. We hypothesize that older, more chemically mature Jamaican bauxites may have had a similar origin. The results add to the growing body of evidence of the importance of multiple parent materials, including far-traveled dust, to soil genesis.

  9. Minimun Pension Insurance in the Chilean Pension System Minimun Pension Insurance in the Chilean Pension System

    Directory of Open Access Journals (Sweden)

    Salvador Zurita

    1994-03-01

    Full Text Available One of the "social" features of the Chilean individual capitalization pension system is the minimum pension scheme. which guarantees its members a minimum pension irrespective of the funds they accumulate, with the only requirement of twenty years of social security tax payments. The purpose of this paper is to estimate the implicit fiscal subsidy, using an option-based approach. We capture the risk associated to the returns on the pension fund account of a worker by modeling its value as a diffusion process and show the correspondence between the minimum pension insurance and a financial put option. Our results are the present value of the minimum pension benefit, equivalent to 3 percent of Chilean GDP for current active and non-active affiliated workers. These estimates are notoriously higher than previous results based on deterministic models, and strongly suggest the importance of explicitly considering the risk associated to pension assets when estimating the cost to the government of the insurance implied by the minimum pension benefit. One of the "social" features of the Chilean individual capitalization pension system is the minimum pension scheme. which guarantees its members a minimum pension irrespective of the funds they accumulate, with the only requirement of twenty years of social security tax payments. The purpose of this paper is to estimate the implicit fiscal subsidy, using an option-based approach. We capture the risk associated to the returns on the pension fund account of a worker by modeling its value as a diffusion process and show the correspondence between the minimum pension insurance and a financial put option. Our results are the present value of the minimum pension benefit, equivalent to 3 percent of Chilean GDP for current active and non-active affiliated workers. These estimates are notoriously higher than previous results based on deterministic models, and strongly suggest the importance of explicitly considering

  10. Independence and regulatory effectiveness: The Chilean experience

    International Nuclear Information System (INIS)

    International binding documents state that Member States should provide an effectively independent Regulatory Body. There are no recommendations on how independent a Regulatory Body must be. As a result, many different regulatory structures are found worldwide. Economical development status of Member States can be easily correlated to their regulatory organizations; nuclear power programs are also decisory. Along the last fifty years, regulatory activities in Chile have gone through several changes: before 1974 radioactive facilities were controlled by the Ministry of Health. A Supreme Decree issued on June 1974, approved the 'Regulations on Licensing (of radioactive facilities)', conferring this faculty to the Chilean Nuclear Energy Commission. The CNEC had, de facto, the same faculties regarding nuclear facilities. The Nuclear Safety Law, published in 1984 stated that the Chilean Nuclear Energy Commission (CNEC) was the competent authority regarding nuclear facilities, while Regional Health Services belonging to the Ministry of Health, were competent over all radioactive facilities. In 1987 the Law No. 18.730 amended the Nuclear Safety Law, transferring the competence over 1st category radioactive facilities and associated matters to the CNEC. In 2004 the Ministry of Health went under a great reorganization: the Law No. 19.937 defined new competent authorities, providing an effective independence of the regulatory functions. In 2001, the Board of Directors of the CNEC delegated the faculty of granting authorizations to the Head of the Nuclear and Radiological Safety Department. In 2005, the Board also delegated the faculties of proposing regulations and standards and prosecuting regulation violators on the person of the Head of the Nuclear and Radiological Safety Department. Both, the Ministry of Health and the CNEC, have given decisory steps towards fulfilling the principle of regulatory independence: the first one by separating functions at the level of

  11. Long-term pollution by chlordecone of tropical volcanic soils in the French West Indies: A simple leaching model accounts for current residue

    Energy Technology Data Exchange (ETDEWEB)

    Cabidoche, Y.-M., E-mail: cabidoch@antilles.inra.f [INRA, UR 135 Agropedoclimatique de la Zone Caraibe, Environment and Agronomy, Domaine Duclos, 97170 Petit-Bourg, Guadeloupe (France); Achard, R., E-mail: achard@cirad.f [CIRAD, UPR Systemes Bananes et Ananas (Martinique), 97285 Le Lamentin (France); Cattan, P., E-mail: cattan@cirad.f [CIRAD, UPR Systemes Bananes et Ananas (Guadeloupe), 97130 Capesterre-Belle-Eau (France); Clermont-Dauphin, C., E-mail: clermont@ird.f [INRA, UR 135 Agropedoclimatique de la Zone Caraibe, Environment and Agronomy, Domaine Duclos, 97170 Petit-Bourg, Guadeloupe (France); Massat, F., E-mail: fmassat@ladrome.f [Laboratoire Departemental d' Analyses de la Drome, LDA26, 26000 Valence (France); Sansoulet, J., E-mail: Julie.Sansoulet@cirad.f [INRA, UR 135 Agropedoclimatique de la Zone Caraibe, Environment and Agronomy, Domaine Duclos, 97170 Petit-Bourg, Guadeloupe (France)

    2009-05-15

    Chlordecone was applied between 1972 and 1993 in banana fields of the French West Indies. This resulted in long-term pollution of soils and contamination of waters, aquatic biota, and crops. To assess pollution level and duration according to soil type, WISORCH, a leaching model based on first-order desorption kinetics, was developed and run. Its input parameters are soil organic carbon content (SOC) and SOC/water partitioning coefficient (K{sub oc}). It accounts for current chlordecone soil contents and drainage water concentrations. The model was valid for andosol, which indicates that neither physico-chemical nor microbial degradation occurred. Dilution by previous deep tillages makes soil scrapping unrealistic. Lixiviation appeared the main way to reduce pollution. Besides the SOC and rainfall increases, K{sub oc} increased from nitisol to ferralsol and then andosol while lixiviation efficiency decreased. Consequently, pollution is bound to last for several decades for nitisol, centuries for ferralsol, and half a millennium for andosol. - Soil and water contamination by chlordecone will persist for several centuries in the French West Indies, because the only decontamination is through leaching by drainage water.

  12. Results of Chilean water markets: Empirical research since 1990

    Science.gov (United States)

    Bauer, Carl J.

    2004-09-01

    Chile's free-market Water Code turned 20 years old in October 2001. This anniversary was an important milestone for both Chilean and international debates about water policy because Chile has become the world's leading example of the free-market approach to water law and water resources management, the textbook case of treating water rights not merely as private property but also as a fully marketable commodity. The predominant view outside of Chile is that Chilean water markets and the Chilean model of water management have been a success, and this perception has encouraged other countries to follow Chile's lead in water law reform. Much of the debate about Chilean water markets, however, has been based more on theoretical or political beliefs than on empirical study. This paper reverses that emphasis by reviewing the evolution of empirical research about these markets since 1990, when Chile returned to democratic government after 16 years of military rule. During the period since 1990, understanding of how Chilean water markets have worked in practice has gradually improved. There have been two major trends in this research: first, a gradual shift from exaggerated claims of the markets' success toward more balanced assessments of mixed results and, second, a heavy emphasis on the economics of water rights trading with very little attention given to the Water Code's impacts on social equity, river basin management, environmental protection, or resolution of water conflicts. The analysis in this study is qualitative and interdisciplinary, combining law, economics, and institutions.

  13. Chilean Nuclear Energy Commission dosimetric information system

    International Nuclear Information System (INIS)

    This thesis discusses the nuclear radiation that people who work with radioactive material is exposed to and its control by the Chilean Nuclear Energy Commission. A full analysis of the System is presented with information about the Commission and the Department of Nuclear and Radiological Safety which runs the System. Ana analysis of the System is presented in order to obtain requirements. Management flow diagrams, the processes involved and current problems experienced by the users are described. A design logic is modeled producing Data Flow Diagrams (DFD). based on this physical design, or, Model of Physical Data, is prepared including tables, attributes, types of data, primary and foreign keys. A description is presented of how the System is implemented, the tools that are used and how the testing phase is carried out. The Dosimetry System meets the criteria for a Software Engineering project, where the basic cycle was used as a working methodology. The System developed supports the dosimetric control of people exposed to radioactive material. (author)

  14. The geothermal system of Caviahue-Copahue Volcanic Complex (Chile-Argentina): New insights from self-potential, soil CO2 degassing, temperature measurements and helium isotopes, with structural and fluid circulation implications.

    Science.gov (United States)

    Roulleau, Emilie; Bravo, Francisco; Barde-Cabusson, Stephanie; Pizarro, Marcela; Muños, Carlos; Sanchez, Juan; Tardani, Daniele; Sano, Yuji; Takahata, Naoto; de Cal, Federico; Esteban, Carlos

    2016-04-01

    Geothermal systems represent natural heat transfer engines in a confined volume of rock which are strongly influenced by the regional volcano-tectonic setting controlling the formation of shallow magmatic reservoirs, and by the local faults/fracture network, that permits the development of hydrothermal circulation cells and promote the vertical migration of fluids and heat. In the Southern Volcanic Zone of Chile-Argentina, geothermal resources occur in close spatial relationship with active volcanism along the Cordillera which is primarily controlled by the 1000 km long, NNE Liquiñe-Ofqui Fault Zone (LOFZ), an intra-arc dextral strike-slip fault system, associated with second-order intra-arc anisotropy of overall NE-SW (extensional) and NW-SE orientation (compressional). However there is still a lack of information on how fault network (NE and WNW strinking faults) and lithology control the fluid circulation. In this study, we propose new data of dense self-potential (SP), soil CO2 emanation and temperature (T) measurements within the geothermal area from Caviahue-Copahue Volcanic Complex (CCVC), coupled with helium isotopes ratios measured in fumaroles and thermal springs. We observe that inside the geothermal system the NE-striking faults, characterized by a combination of SP-CO2 and T maxima with high 3He/4He ratios (7.86Ra), promote the formation of high vertical permeability pathways for fluid circulation. Whereas, the WNW-striking faults represent low permeability pathways for hydrothermal fluids ascent associated with moderate 3He/4He ratios (5.34Ra), promoting the infiltration of meteoric water at shallow depth. These active zones are interspersed by SP-CO2- T minima, which represent self-sealed zones (e.g. impermeable altered rocks) at depth, creating a barrier inhibiting fluids rise. The NE-striking faults seem to be associated with the upflow zones of the geothermal system, where the boiling process produces a high vapor-dominated zone close to the

  15. The fate of uranium contaminants of phosphate fertiliser: chemical partitioning of uranium in two New Zealand soils of volcanic origin and the effect on partitioning of amending one of those soils with uranium

    International Nuclear Information System (INIS)

    This study assessed the chemical partitioning of U isotopes in Horomanga Sandy Loam and Te Kowhai silt loam, two agricultural soils derived from rhyolitic ash and receiving low level contamination from U impurities in phosphate fertiliser. To simulate future U additions, a sub-sample of the Horomanga soil was amended with 2.259 μg U g-1 soil before sequential extraction. The hypothesis that U additions will be strongly held on to the soil and are not available for leaching or plant uptake was tested. After extraction U was purified and determined by alpha spectrometry. Results were corrected for tailing, background, for losses in the purification process (using 232U), and for soil moisture. It is concluded that only a small proportion of U in the two type of soils examined was derived from fertiliser and that very little U would be available to plants or to leaching

  16. Tellurium in active volcanic environments: Preliminary results

    Science.gov (United States)

    Milazzo, Silvia; Calabrese, Sergio; D'Alessandro, Walter; Brusca, Lorenzo; Bellomo, Sergio; Parello, Francesco

    2014-05-01

    Tellurium is a toxic metalloid and, according to the Goldschmidt classification, a chalcophile element. In the last years its commercial importance has considerably increased because of its wide use in solar cells, thermoelectric and electronic devices of the last generation. Despite such large use, scientific knowledge about volcanogenic tellurium is very poor. Few previous authors report result of tellurium concentrations in volcanic plume, among with other trace metals. They recognize this element as volatile, concluding that volcanic gases and sulfur deposits are usually enriched with tellurium. Here, we present some results on tellurium concentrations in volcanic emissions (plume, fumaroles, ash leachates) and in environmental matrices (soils and plants) affected by volcanic emissions and/or deposition. Samples were collected at Etna and Vulcano (Italy), Turrialba (Costa Rica), Miyakejima, Aso, Asama (Japan), Mutnovsky (Kamchatka) at the crater rims by using common filtration techniques for aerosols (polytetrafluoroethylene filters). Filters were both eluted with Millipore water and acid microwave digested, and analyzed by inductively coupled plasma mass spectrometry (ICP-MS). Volcanic ashes emitted during explosive events on Etna and Copahue (Argentina) were analyzed for tellurium bulk composition and after leaching experiments to evaluate the soluble fraction of tellurium. Soils and leaves of vegetation were also sampled close to active volcanic vents (Etna, Vulcano, Nisyros, Nyiragongo, Turrialba, Gorely and Masaya) and investigated for tellurium contents. Preliminary results showed very high enrichments of tellurium in volcanic emissions comparing with other volatile elements like mercury, arsenic, thallium and bismuth. This suggests a primary transport in the volatile phase, probably in gaseous form (as also suggested by recent studies) and/or as soluble salts (halides and/or sulfates) adsorbed on the surface of particulate particles and ashes. First

  17. Association between eating behavior scores and obesity in Chilean children

    Directory of Open Access Journals (Sweden)

    Amador Paola

    2011-10-01

    Full Text Available Abstract Background Inadequate eating behavior and physical inactivity contribute to the current epidemic of childhood obesity. The aim of this study was to assess the association between eating behavior scores and childhood obesity in Chilean children. Design and methods We recruited 126 obese, 44 overweight and 124 normal-weight Chilean children (6-12 years-old; both genders according to the International Obesity Task Force (IOTF criteria. Eating behavior scores were calculated using the Child Eating Behavior Questionnaire (CEBQ. Factorial analysis in the culturally-adapted questionnaire for Chilean population was used to confirm the original eight-factor structure of CEBQ. The Cronbach's alpha statistic (>0.7 in most subscales was used to assess internal consistency. Non-parametric methods were used to assess case-control associations. Results Eating behavior scores were strongly associated with childhood obesity in Chilean children. Childhood obesity was directly associated with high scores in the subscales "enjoyment of food" (P Conclusion Our study shows a strong and graded association between specific eating behavior scores and childhood obesity in Chile.

  18. Prevalence and risk factors for bruises in Chilean bovine carcasses

    NARCIS (Netherlands)

    Strappini, A.C.; Frankena, K.; Metz, J.H.M.; Kemp, B.

    2010-01-01

    Records of cattle slaughtered at two Chilean slaughterhouses (SLH1 and SLH2) were used to determine prevalence and risk factors for carcasses with bruises. Bruise prevalence amounted to 12.3% but differed between slaughterhouses (20.8% for SLH1 and 8.6% for SLH2 respectively). Bruise severity grade

  19. Amino acid biogeo- and stereochemistry in coastal Chilean sediments

    DEFF Research Database (Denmark)

    Lomstein, Bente Aagaard; Jørgensen, Bo Barker; Schubert, Carsten J.;

    2006-01-01

    The spatial distribution of total hydrolysable amino acids (THAA) and amino acid enantiomers (D- and L-forms) was investigated in sediments underlying two contrasting Chilean upwelling regions,: at ~23°S off Antofagasta and at ~36°S off Concepcion. The contribution of amino acids to total organic...

  20. Volcanic signals in oceans

    KAUST Repository

    Stenchikov, Georgiy L.

    2009-08-22

    Sulfate aerosols resulting from strong volcanic explosions last for 2–3 years in the lower stratosphere. Therefore it was traditionally believed that volcanic impacts produce mainly short-term, transient climate perturbations. However, the ocean integrates volcanic radiative cooling and responds over a wide range of time scales. The associated processes, especially ocean heat uptake, play a key role in ongoing climate change. However, they are not well constrained by observations, and attempts to simulate them in current climate models used for climate predictions yield a range of uncertainty. Volcanic impacts on the ocean provide an independent means of assessing these processes. This study focuses on quantification of the seasonal to multidecadal time scale response of the ocean to explosive volcanism. It employs the coupled climate model CM2.1, developed recently at the National Oceanic and Atmospheric Administration\\'s Geophysical Fluid Dynamics Laboratory, to simulate the response to the 1991 Pinatubo and the 1815 Tambora eruptions, which were the largest in the 20th and 19th centuries, respectively. The simulated climate perturbations compare well with available observations for the Pinatubo period. The stronger Tambora forcing produces responses with higher signal-to-noise ratio. Volcanic cooling tends to strengthen the Atlantic meridional overturning circulation. Sea ice extent appears to be sensitive to volcanic forcing, especially during the warm season. Because of the extremely long relaxation time of ocean subsurface temperature and sea level, the perturbations caused by the Tambora eruption could have lasted well into the 20th century.

  1. Origins of the Chilean Binominal Election System

    Directory of Open Access Journals (Sweden)

    Daniel Pastor

    2004-01-01

    Full Text Available strategic reaction by the military regime to the defeat of General Augusto Pinochet in the 1988 Plebiscite since the system was formally established during the period between the plebiscite and the first postauthoritarian elections in 1989. This theory, however, offers a mistaken account of the history and evolution of the binominal election system whose origins are considerably more complex than the conventional wisdom suggests. This article explores the internal political processes and the ideology that led the military government to adopt the binominal system. It argues that the election system was the capstone of the authoritarian institutional framework designed by the military government to protect the 1980 Constitution from efforts by the Concertación to reform it. Contrary to popular belief, the binominal system was proposed long before the 1988 Plebiscite by Arturo Marín Vicuña, then secretary of a government commission studying a new electoral law. This article maintains that, more than any other factor, the binominal system reflects and responds to an interpretation of Chilean political history between 1960 and 1973 that was widely shared among the Pinochet government's legal advisorsSe ha asumido que el presente sistema electoral chileno -el "binominal mayoritario"- fue una reacción ante la derrota del General Augusto Pinochet en el plebiscito de 1988, ya que fue lanzado en el intermedio después del plebiscito, pero antes que el régimen militar abandonara el poder. No obstante, esta hipótesis se equivoca en la historia de la evolución del sistema binominal que es más complejo. Este artículo explora la historia de los procesos políticos dentro del régimen militar y la ideología que llevó al sistema binominal. Argumenta que el sistema binominal fue la piedra arquitectónica de la institucionalidad autoritaria del régimen militar que protegía su Constitución de 1980 contra los esfuerzos de la Concertación para

  2. The Potential of Low-Frequency (16-80 MHz) Ground Penetrating Radar to Investigate the Shallow Subsurface in the Arid, Volcanic, and Conductive Soils Near Yucca Mountain: Implications for MARSIS and SHARAD

    Science.gov (United States)

    Heggy, E.; Clifford, S.; Grimm, R.; Dinwiddie, C. L.

    2004-05-01

    In March 2004, the MARSIS radar sounder aboard the Mars Express spacecraft will begin acquiring the first of what will eventually be a global data set of the radar properties of the Martian subsurface within the frequency range of 0.5-5 MHz. Because no MARSIS prototype was ever built, and only limited GPR investigations of the Earth have been made within this frequency range, we plan to conduct a comprehensive radar investigation of a number of well-characterized terrestrial analog sites over the range of frequencies that will be employed by MARSIS and future Mars radars. The ability of these radars to determine the subsurface stratigraphy, structure, and distribution and aqueous history of water on Mars will be strongly dependent on the physical properties, mineralogy, and thermal structure of the subsurface-properties that will define the electrical and magnetic characteristics and ultimately determine the propagation, scattering and reflective properties of the crust. The arid volcanic environment around Yucca Mountain, Nevada has many similarities to the geologic environment of Mars. For example, the soil mineralogy is dominated by the presence of iron oxides, materials that can result in significant electrical and magnetic losses to the radar signal, thus affecting the maximum sounding depth and depth at which any subsurface feature can be identified. In order to evaluate and quantify the magnitude of these losses, we performed a 16 - 80 MHz GPR survey at several well-characterized areas in a region to the southwest of Yucca Mountain. A principal goal of this survey is to determine the extent to which these adverse soil properties influence the identification of subsurface stratigraphy, structure, and a water table at depths ranging from several tens to hundreds of meters.. We will present a summary of the field and laboratory data acquired during this survey and discuss its implications for radar sounding investigations of Mars

  3. Main musculoskeletal injuries associated with lameness in Chilean Rodeo horses

    Directory of Open Access Journals (Sweden)

    M Mora-Carreño

    2014-01-01

    Full Text Available Chilean Rodeo is the most popular equestrian discipline in Chile and it is estimated that musculoskeletal diseases of the equine participants are the leading cause of illness and poor performance, however no related reports have been published. The aim of this study was to identify and characterize the main diseases associated with lameness in Chilean Rodeo horses. A retrospective study was performed considering the clinical attention records of horses participating in Chilean Rodeo which presented lameness. Information was collected regarding 114 cases, including identification (name, age and gender and the clinical characteristics of each episode. The average age of the horses was 8 ± 3.4 years. Among the subjects, 98.3% of the episodes corresponded to spontaneous lameness, with 2/4 being the most frequent degree of lameness. Unilateral episodes corresponded to 72.8% (83/114 of the cases, affecting primarily the front limbs (51/83. The most frequent diagnoses were: suspensory ligament desmitis (14%, tarsal osteoarthritis (13.2%, navicular syndrome (8.8%, laminitis (7.9%, deep digital flexor tendonitis (7% and metacarpophalangeal osteoarthritis (6.1%. The high frequency of grade 2 lameness suggests that the majority of veterinary attentions seem to be mostly at obvious conditions. Joint, foot and soft tissue conditions seem to be the main cause of lameness in equines participating in Chilean Rodeo. These results suggest that education regarding the importance of early diagnosis and greater hoof care are primary measures that may favor the prevention of lameness in Chilean Rodeo horses.

  4. Continuous in situ measurements of volcanic gases with a diode-laser-based spectrometer: CO2 and H2O concentration and soil degassing at Vulcano (Aeolian islands: Italy

    Directory of Open Access Journals (Sweden)

    De Natale Paolo

    2007-04-01

    Full Text Available Abstract We report on a continuous-measurement campaign carried out in Vulcano (Aeolian islands, Sicily, devoted to the simultaneous monitoring of CO2 and H2O concentrations. The measurements were performed with an absorption spectrometer based on a semiconductor laser source emitting around a 2-μm wavelength. The emitted radiation was selectively absorbed by two molecular ro-vibrational transitions specific of the investigated species. Data for CO2 and H2O concentrations, and CO2 soil diffusive flux using an accumulation chamber configuration, were collected at several interesting sampling points on the island (Porto Levante beach- PLB, Fossa Grande Crater – FOG- and Valley of Palizzi, PAL. CO2/H2O values, measured on the ground, are very similar (around 0.019 (± 0.006 and comparable to the previous discrete detected values of 0.213 (Fumarole F5-La Fossa crater rim and 0.012 (Fumarole VFS – Baia Levante beach obtaid during the 1977–1993 heating phase of the crater fumaroles. In this work much more homogeneous values are found in different points of the three sites investigated. The field work, although carried out in a limited time window (25th–28th August 2004, pointed out the new apparatus is suitable for continuous gas monitoring of the two species and their ratios, which are important geochemical indicators of volcanic activity, for which other reliable continuous monitoring systems are not yet available.

  5. Characterization of the atrazine sorption process on Andisol and Ultisol volcanic ash-derived soils: kinetic parameters and the contribution of humic fractions.

    Science.gov (United States)

    Báez, María E; Fuentes, Edwar; Espinoza, Jeannette

    2013-07-01

    Atrazine sorption was studied in six Andisol and Ultisol soils. Humic and fulvic acids and humin contributions were established. Sorption on soils was well described by the Freundlich model. Kf values ranged from 2.2-15.6 μg(1-1/n)mL(1/n)g⁻¹. The relevance of humic acid and humin was deduced from isotherm and kinetics experiments. KOC values varied between 221 and 679 mLg⁻¹ for these fractions. Fulvic acid presented low binding capacity. Sorption was controlled by instantaneous equilibrium followed by a time-dependent phase. The Elovich equation, intraparticle diffusion model, and a two-site nonequilibrium model allowed us to conclude that (i) there are two rate-limited phases in Andisols related to intrasorbent diffusion in organic matter and retarded intraparticle diffusion in the organo-mineral complex and that (ii) there is one rate-limited phase in Ultisols attributed to the mineral composition. The lower organic matter content of Ultisols and the slower sorption rate and mechanisms involved must be considered to assess the leaching behavior of atrazine. PMID:23711282

  6. Volcanic Rocks and Features

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Volcanoes have contributed significantly to the formation of the surface of our planet. Volcanism produced the crust we live on and most of the air we breathe. The...

  7. Volcanic hazard assessment in monogenetic volcanic fields

    OpenAIRE

    Bartolini, Stefania

    2014-01-01

    Tesi realitzada a l'Institut de Ciències de la Terra “Jaume Almera” (ICTJA-CSIC) One of the most important tasks of modern volcanology, which represents a significant socio-economic implication, is to conduct hazard assessment in active volcanic systems. These volcanological studies are aimed at hazard that allows to constructing hazard maps and simulating different eruptive scenarios, and are mainly addressed to contribute to territorial planning, definition of emergency plans or managing...

  8. Some isotopic and geochemical anomalies observed in Mexico prior to large scale earthquakes and volcanic eruptions

    Energy Technology Data Exchange (ETDEWEB)

    Cruz R, S. de la; Armienta, M.A.; Segovia A, N

    1992-05-15

    A brief account of some experiences obtained in Mexico, related with the identification of geochemical precursors of volcanic eruptions and isotopic precursors of earthquakes and volcanic activity is given. The cases of three recent events of volcanic activity and one large earthquake are discussed in the context of an active geological environment. The positive results in the identification of some geochemical precursors that helped to evaluate the eruptive potential during two volcanic crises (Tacana 1986 and Colima 1991), and the significant radon-in-soil anomalies observed during a volcanic catastrophic eruption (El Chichon, 1982) and prior to a major earthquake (Michoacan, 1985) are critically analysed. (Author)

  9. Some isotopic and geochemical anomalies observed in Mexico prior to large scale earthquakes and volcanic eruptions

    International Nuclear Information System (INIS)

    A brief account of some experiences obtained in Mexico, related with the identification of geochemical precursors of volcanic eruptions and isotopic precursors of earthquakes and volcanic activity is given. The cases of three recent events of volcanic activity and one large earthquake are discussed in the context of an active geological environment. The positive results in the identification of some geochemical precursors that helped to evaluate the eruptive potential during two volcanic crises (Tacana 1986 and Colima 1991), and the significant radon-in-soil anomalies observed during a volcanic catastrophic eruption (El Chichon, 1982) and prior to a major earthquake (Michoacan, 1985) are critically analysed. (Author)

  10. Air Pollution by Hydrothermal Volcanism and Human Pulmonary Function

    OpenAIRE

    Diana Linhares; Patrícia Ventura Garcia; Fátima Viveiros; Teresa Ferreira; Armindo dos Santos Rodrigues

    2015-01-01

    The aim of this study was to assess whether chronic exposure to volcanogenic air pollution by hydrothermal soil diffuse degassing is associated with respiratory defects in humans. This study was carried in the archipelago of the Azores, an area with active volcanism located in the Atlantic Ocean where Eurasian, African, and American lithospheric plates meet. A cross-sectional study was performed on a study group of 146 individuals inhabiting an area where volcanic activity is marked by active...

  11. Surface Coatings on Lunar Volcanic Glasses

    Science.gov (United States)

    Wentworth, Susan J.; McKay, D. S.; Thomas,-Keprta, K. L.; Clemett, S. J.

    2007-01-01

    We are undertaking a detailed study of surface deposits on lunar volcanic glass beads. These tiny deposits formed by vapor condensation during cooling of the gases that drove the fire fountain eruptions responsible for the formation of the beads. Volcanic glass beads are present in most lunar soil samples in the returned lunar collection. The mare-composition beads formed as a result of fire-fountaining approx.3.4-3.7 Ga ago, within the age range of large-scale mare volcanism. Some samples from the Apollo 15 and Apollo 17 landing sites are enriched in volcanic spherules. Three major types of volcanic glass bead have been identified: Apollo 15 green glass, Apollo 17 orange glass, and Apollo 17 "black" glass. The Apollo 15 green glass has a primitive composition with low Ti. The high-Ti compositions of the orange and black glasses are essentially identical to each other but the black glasses are opaque because of quench crystallization. A poorly understood feature common to the Apollo 15 and 17 volcanic glasses is the presence of small deposits of unusual materials on their exterior surfaces. For example, early studies indicated that the Apollo 17 orange glasses had surface enrichments of In, Cd, Zn, Ga, Ge, Au, and Na, and possible Pb- and Zn-sulfides, but it was not possible to characterize the surface features in detail. Technological advances now permit us to examine such features in detail. Preliminary FE-TEM/X-ray studies of ultramicrotome sections of Apollo 15 green glass indicate that the surface deposits are heterogeneous and layered, with an inner layer consisting of Fe with minor S and an outer layer of Fe and no S, and scattered Zn enrichments. Layering in surface deposits has not been identified previously; it will be key to defining the history of lunar fire fountaining.

  12. The Chilean Health System: 20 Years of Reforms

    Directory of Open Access Journals (Sweden)

    Manuel Annick

    2002-01-01

    Full Text Available The Chilean health care system has been intensively reformed in the past 20 years. Reforms under the Pinochet government (1973-1990 aimed mainly at the decentralization of the system and the development of a private sector. Decentralization involved both a deconcentration process and the devolution of primary health care to municipalities. The democratic governments after 1990 chose to preserve the core organization but introduced reforms intended to correct the system's failures and to increase both efficiency and equity. The present article briefly explains the current organization of the Chilean health care system. It also reviews the different reforms introduced in the past 20 years, from the Pinochet regime to the democratic governments. Finally, a brief discussion describes the strengths and weaknesses of the system, as well as the challenges it currently faces.

  13. Characterization of chlordecone-tolerant fungal populations isolated from long-term polluted tropical volcanic soil in the French West Indies.

    Science.gov (United States)

    Merlin, Chloé; Devers, Marion; Crouzet, Olivier; Heraud, Cécile; Steinberg, Christian; Mougin, Christian; Martin-Laurent, Fabrice

    2014-04-01

    The insecticide chlordecone is a contaminant found in most of the banana plantations in the French West Indies. This study aims to search for fungal populations able to grow on it. An Andosol heavily contaminated with chlordecone, perfused for 1 year in a soil-charcoal system, was used to conduct enrichment cultures. A total of 103 fungal strains able to grow on chlordecone-mineral salt medium were isolated, purified, and deposited in the MIAE collection (Microorganismes d'Intérêt Agro-Environnemental, UMR Agroécologie, Institut National de la Recherche Agronomique, Dijon, France). Internal transcribed spacer sequencing revealed that all isolated strains belonged to the Ascomycota phylum and gathered in 11 genera: Metacordyceps, Cordyceps, Pochonia, Acremonium, Fusarium, Paecilomyces, Ophiocordyceps, Purpureocillium, Bionectria, Penicillium, and Aspergillus. Among predominant species, only one isolate, Fusarium oxysporum MIAE01197, was able to grow in a liquid culture medium that contained chlordecone as sole carbon source. Chlordecone increased F. oxysporum MIAE01197 growth rate, attesting for its tolerance to this organochlorine. Moreover, F. oxysporum MIAE01197 exhibited a higher EC50 value than the reference strain F. oxysporum MIAE00047. This further suggests its adaptation to chlordecone tolerance up to 29.2 mg l(-1). Gas chromatography-mass spectrometry (GC-MS) analysis revealed that 40 % of chlordecone was dissipated in F. oxysporum MIAE01197 suspension culture. No chlordecone metabolite was detected by GC-MS. However, weak amount of (14)CO2 evolved from (14)C10-chlordecone and (14)C10-metabolites were observed. Sorption of (14)C10-chlordecone onto fungal biomass followed a linear relationship (r (2) = 0.99) suggesting that it may also account for chlordecone dissipation in F. oxysporum MIAE01197 culture. PMID:23872892

  14. Volcanic hazards to airports

    Science.gov (United States)

    Guffanti, M.; Mayberry, G.C.; Casadevall, T.J.; Wunderman, R.

    2009-01-01

    Volcanic activity has caused significant hazards to numerous airports worldwide, with local to far-ranging effects on travelers and commerce. Analysis of a new compilation of incidents of airports impacted by volcanic activity from 1944 through 2006 reveals that, at a minimum, 101 airports in 28 countries were affected on 171 occasions by eruptions at 46 volcanoes. Since 1980, five airports per year on average have been affected by volcanic activity, which indicates that volcanic hazards to airports are not rare on a worldwide basis. The main hazard to airports is ashfall, with accumulations of only a few millimeters sufficient to force temporary closures of some airports. A substantial portion of incidents has been caused by ash in airspace in the vicinity of airports, without accumulation of ash on the ground. On a few occasions, airports have been impacted by hazards other than ash (pyroclastic flow, lava flow, gas emission, and phreatic explosion). Several airports have been affected repeatedly by volcanic hazards. Four airports have been affected the most often and likely will continue to be among the most vulnerable owing to continued nearby volcanic activity: Fontanarossa International Airport in Catania, Italy; Ted Stevens Anchorage International Airport in Alaska, USA; Mariscal Sucre International Airport in Quito, Ecuador; and Tokua Airport in Kokopo, Papua New Guinea. The USA has the most airports affected by volcanic activity (17) on the most occasions (33) and hosts the second highest number of volcanoes that have caused the disruptions (5, after Indonesia with 7). One-fifth of the affected airports are within 30 km of the source volcanoes, approximately half are located within 150 km of the source volcanoes, and about three-quarters are within 300 km; nearly one-fifth are located more than 500 km away from the source volcanoes. The volcanoes that have caused the most impacts are Soufriere Hills on the island of Montserrat in the British West Indies

  15. Women and changes in the Chilean economy: some questions.

    Science.gov (United States)

    Smiaroski, M S

    1996-10-01

    The author argues that a new development model that encourages greater participation of women in the work force in domestic piecework, temporary work, and subcontracting may further lead to the exploitation of women in Chile. The importance of women in economic development in Chile should be based on building skills, providing support child care services, reorienting women's education, and tax incentives. Chile over the past decade has achieved relatively stable economic growth and increased employment of women. During 1990-93 the growth of women in the work force increased at a rate of 16.8%, while men's presence increased by only 9.8%. The Chilean economy is based on a sophisticated modern sector and a labor-intensive informal sector. The Chilean model of development relies on cheap, flexible labor and a government approval of this model. Increased participation of women in the labor force is usually perceived as increased economic empowerment. A 1994 Oxfam study found that women were being forced into the labor market due to declines in family income and low wages. 46% of men and women received wages that did not cover basic necessities. The Chilean labor market is gender-stratified. Men are paid better than women for the same work. Men are in more permanent positions. Labor laws are either inadequate or violated, particularly for hours of work and overtime pay and conditions of employment and benefits. Traditional female jobs are those that rely on women's natural attributes. These unskilled attributes are rewarded with low wages. Little opportunity is provided for upgrading skills or acquiring new skills. Some women turn down advancement because of a lack of role models. Women have little opportunity to develop their self-image as workers. Poor self-images affect women's work attitudes and motivation. Some firms use competition between women to boost production. Chilean women remain in subordinate roles.

  16. [Minimum legal drinking age in the Chilean context].

    Science.gov (United States)

    Ramírez, Jorge; Heller, Nereida

    2016-01-01

    Alcohol consumption is harmful to minors. One of the most wide ly accepted measures for the prevention of harm associated with alcohol consumption for young people is to establish a minimum legal drinking age. This document presents the evidence available on this policy, offers a condensed analysis of its characteristics in the United States of America, describes current consumption patterns of Chilean youth, and proposes concrete solutions to be implemented. PMID:26998989

  17. EMPIRICAL REGULARITIES OF THE CHILEAN ECONOMY: 1986-2005

    OpenAIRE

    Jorge Enrique Restrepo L.; Claudio Soto G.

    2006-01-01

    This paper documents the main empirical regularities of the Chilean economy over the past twenty years, characterizing it in two dimensions. First, it describes the economy’s structure in terms of the sectors’ relative sizes in the long term and the importance of the various components of aggregate demand. Second, it documents the main features of business cycles in Chile. The volatility and persistence of several variables across the cycles is described, together with the correlations within...

  18. A New Liquidity Risk Measure for the Chilean Banking Sector

    OpenAIRE

    Sebastián Becerra; Gregory Claeys; Juan Francisco Martínez

    2015-01-01

    The objective of this work is to construct an appropriate measure of liquidity risk for Chilean banks. There are already several measures of liquidity risk in the literature. Most of these metrics are based on specific assumptions and expert opinion. In order to overcome the potential problems associated with discretionary assumptions, and to exploit the information available, similar to the work of Drehman and Nikolaou (2012), we propose a metric based on the behavior of banks in the procure...

  19. Bank Lending and Relationship Banking: Evidence from Chilean Firms

    OpenAIRE

    Andrea Repetto; Sergio Rodríguez; Valdés, Rodrigo O.

    2002-01-01

    In this paper we empirically study bank-client relationships using a sample of manufacturing Chilean firms. We examine whether concentration and the duration of bank-firm relationships affect the terms of bank financing, evaluating both the volume of bank lending and bank loan costs. Our results indicate that lower concentration, measured by the number of banks a firm borrows from, is associated with lower costs of loans and with a large and positive non-lincar effect on borrowing. The length...

  20. The social and cultural impact of advertising among chilean youths

    OpenAIRE

    Vergara-Leyton, Enrique; Rodríguez-Salineros, Maite

    2010-01-01

    This work analyzes the impact of advertising among Chilean youngsters of different socioeconomic background. We aim to identify the relationship that this group establishes with advertising and, in particular, the way they incorporate it in their socialization strategies. We do not address what advertising does to youngsters, but instead what youngsters do with advertising in their practices of appropriation and reception of it. The research design included focus groups of male and female you...

  1. Organic Entrainment and Preservation in Volcanic Glasses

    Science.gov (United States)

    Wilhelm, Mary Beth; Ojha, Lujendra; Brunner, Anna E.; Dufek, Josef D.; Wray, James Joseph

    2014-01-01

    Unaltered pyroclastic deposits have previously been deemed to have "low" potential for the formation, concentration and preservation of organic material on the Martian surface. Yet volcanic glasses that have solidified very quickly after an eruption may be good candidates for containment and preservation of refractory organic material that existed in a biologic system pre-eruption due to their impermeability and ability to attenuate UV radiation. Analysis using NanoSIMS of volcanic glass could then be performed to both deduce carbon isotope ratios that indicate biologic origin and confirm entrainment during eruption. Terrestrial contamination is one of the biggest barriers to definitive Martian organic identification in soil and rock samples. While there is a greater potential to concentrate organics in sedimentary strata, volcanic glasses may better encapsulate and preserve organics over long time scales, and are widespread on Mars. If volcanic glass from many sites on Earth could be shown to contain biologically derived organics from the original environment, there could be significant implications for the search for biomarkers in ancient Martian environments.

  2. The lower cretaceous volcanism in the coastal range of Central Chile: Geochronology and isotopic geochemistry

    International Nuclear Information System (INIS)

    Major factors involved in subduction zone magmatism are related to the melting of the underlying mantle, which can contain a component of aqueous fluid and/or melts derived from the subducting plate (e.g. Peate et al., 1997). The Chilean Pacific margin is a subduction zone, active from Early Mesozoic to now, in which the magmatic arc emplaced on the Paleozoic basement progressively migrate to the east. The western part of this arc constitutes the Coastal Range. In this work, isotopic and radiometric data from four E-W profiles along c. 500 km of the Lower Cretaceous volcanic rocks in the Coastal Range of Chile are presented. The aim of this research is to obtain a model for the genesis of this Cretaceous volcanic arc based on their isotopic signature (au)

  3. Along-strike Variations of Subduction Parameters at the Chilean Plate Boundary

    Science.gov (United States)

    Hoffmann-Rothe, A.; Kukowski, N.; Oncken, O.

    2004-12-01

    Newly compiled data of the geometric, kinematic and mechanic properties and their variations along-strike the oblique Chilean subduction margin between 20° S and 46° S are used to weigh their competing influence on forearc deformation. Special emphasis lies on the formation of margin-parallel strike-slip systems. Among the parameters considered are the convergence rate and obliquity, the ocean floor age, the dip of the down-going and the slope of the overriding plate, the geodetic and seismic coupling depth, the interplate seismicity, the depth of the trench-fill and the mass transfer mode at the subduction front. Commonly discussed control factors for forearc deformation can be attributed to three major elements of a subduction system, namely (1) the plate kinematic boundary conditions, (2) the plate coupling properties that govern the effectiveness of force transmission from the subducting plate to the overriding plate, and (3) the upper plate heterogeneities affecting its rheology (e.g. elasticity, shear strength) or resistance to block motion (buttressing). An example is given for each of these elements: (1) Oblique convergence is a pre-requisite for the activation of margin-parallel strike-slip systems, but apparently not a sufficient condition. For example, strike-slip motion can presently be observed along the Liquiñe-Ofqui Fault Zone in southern Chile, while neither the Atacama Fault Zone nor the Precordilleran Fault System in northern Chile accommodate significant amounts of margin-parallel slip since the Pliocene. This difference can not be explained by variations of convergence rate or obliquity as the plate kinematic framework is almost constant along the Chilean trench. (2) The plate coupling force is a function of the frictionally coupled area on the plate interface and of the shear friction that needs to be overcome. Along the Chilean margin various factors affect coupling in opposing manner: The slab-dip is shallower in southern Chile compared to

  4. Volcanism and Oil & Gas In Northeast China

    Institute of Scientific and Technical Information of China (English)

    Shan Xuanlong

    2000-01-01

    Based on study on the relation with volcanic rock and oil & gas in Songliao Basin and Liaohe Basin in northeast China, author proposes that material from deep by volcanism enrichs the resources in basins, that heat by volcanism promotes organic matter transforming to oil and gas, that volcanic reservoir is fracture, vesicular, solution pore, intercrystal pore.Lava facies and pyroclastic facies are favourable reservoir. Mesozoic volcanic reservoir is majority of intermediate, acid rock,but Cenozoic volcanic reservoir is majority of basalt. Types of oil and gas pool relating to volcanic rock include volcanic fracture pool, volcanic unconformity pool, volcanic rock - screened pool, volcanic darpe structural pool.

  5. Modeling volcanic ash dispersal

    CERN Document Server

    CERN. Geneva

    2010-01-01

    The assessment of volcanic fallout hazard is an important scientific, economic, and political issue, especially in densely populated areas. From a scientific point of view, considerable progress has been made during the last two decades through the use of increasingly powerful computational models and capabilities. Nowadays, models are used to quantify hazard...

  6. Plant Level Evidence on Product Mix Changes in Chilean Manufacturing

    OpenAIRE

    Lucas Navarro

    2008-01-01

    This paper analyzes changes in the product mix by Chilean manufacturing plants in the period 1996-2003. Three-quarters of the surviving plants changed the set of products produced and more than three-quarters of the exporting plants changed the mix of products they exported during the sample period. Plants that changed their product mix contributed 85% of the aggregate growth in real sales of surviving plants between 1996 and 2003. Finally and in contrast to the US evidence, there is a negati...

  7. THE RESPONSE OF MONTEREY BAY TO THE 2010 CHILEAN EARTHQUAKE

    Directory of Open Access Journals (Sweden)

    Laurence C. Breaker

    2011-01-01

    Full Text Available The primary frequencies contained in the arrival sequence produced by the tsunami from the Chilean earthquake of 2010 in Monterey Bay were extracted to determine the seiche modes that were produced. Singular Spectrum Analysis (SSA and Ensemble Empirical Mode Decomposition (EEMD were employed to extract the primary frequencies of interest. The wave train from the Chilean tsunami lasted for at least four days due to multipath arrivals that may not have included reflections from outside the bay but most likely did include secondary undulations, and energy trapping in the form of edge waves, inside the bay. The SSA decomposition resolved oscillations with periods of 52-57, 34-35, 26-27, and 21-22 minutes, all frequencies that have been predicted and/or observed in previous studies. The EEMD decomposition detected oscillations with periods of 50-55 and 21-22 minutes. Periods in the range of 50-57 minutes varied due to measurement uncertainties but almost certainly correspond to the first longitudinal mode of oscillation for Monterey Bay, periods of 34-35 minutes correspond to the first transverse mode of oscillation that assumes a nodal line across the entrance of the bay, a period of 26- 27 minutes, although previously observed, may not represent a fundamental oscillation, and a period of 21-22 minutes has been predicted and observed previously. A period of ~37 minutes, close to the period of 34-35 minutes, was generated by the Great Alaskan Earthquake of 1964 in Monterey Bay and most likely represents the same mode of oscillation. The tsunamis associated with the Great Alaskan Earthquake and the Chilean Earthquake both entered Monterey Bay but initially arrived outside the bay from opposite directions. Unlike the Great Alaskan Earthquake, however, which excited only one resonant mode inside the bay, the Chilean Earthquake excited several modes suggesting that the asymmetric shape of the entrance to Monterey Bay was an important factor and that the

  8. Misconception p value among Chilean and Italian academic psychologists

    Directory of Open Access Journals (Sweden)

    Laura Badenes-Ribera

    2016-08-01

    Full Text Available The p value misconceptions are based on certain beliefs and attributions about the significance of the results. Thus, they affect the professionals’ decisions and jeopardize the quality of interventions and the accumulation of valid scientific knowledge. We conducted a survey on 164 academic psychologists (134 Italians, 30 Chileans, questioned on this topic. Our findings are consistent with original research and suggest that some participants do not know how to correctly interpret p values. The inverse probability fallacy presents the greatest comprehension problems, followed by the replication fallacy. These results highlight the importance of the statistical re-education of researchers. Recommendations for improving statistical cognition are proposed.

  9. Chilean Prosopis Mesocarp Flour: Phenolic Profiling and Antioxidant Activity

    OpenAIRE

    Guillermo Schmeda-Hirschmann; Cristina Quispe; Maria del Pilar C. Soriano; Cristina Theoduloz; Felipe Jiménez-Aspée; Maria Jorgelina Pérez; Ana Soledad Cuello; Maria Inés Isla

    2015-01-01

    In South America, the mesocarp flour of Prosopis species plays a prominent role as a food resource in arid areas. The aim of this work was the characterization of the phenolic antioxidants occurring in the pod mesocarp flour of Chilean Prosopis. Samples were collected in the Copiapo, Huasco and Elqui valleys from the north of Chile. The samples of P. chilensis flour exhibited a total phenolic content ranging between 0.82–2.57 g gallic acid equivalents/100 g fresh flour weight. The highest ant...

  10. Exploring Hawaiian volcanism

    Science.gov (United States)

    Poland, Michael P.; Okubo, Paul G.; Hon, Ken

    2013-01-01

    In 1912 the Hawaiian Volcano Observatory (HVO) was established by Massachusetts Institute of Technology professor Thomas A. Jaggar Jr. on the island of Hawaii. Driven by the devastation he observed while investigating the volcanic disasters of 1902 at Montagne Pelée in the Caribbean, Jaggar conducted a worldwide search and decided that Hawai‘i provided an excellent natural laboratory for systematic study of earthquake and volcano processes toward better understanding of seismic and volcanic hazards. In the 100 years since HVO’s founding, surveillance and investigation of Hawaiian volcanoes have spurred advances in volcano and seismic monitoring techniques, extended scientists’ understanding of eruptive activity and processes, and contributed to development of global theories about hot spots and mantle plumes.

  11. Reducing volcanic risk

    Science.gov (United States)

    Decker, R.; Decker, B.

    1991-01-01

    The last two decades have brought major advances in research on how volcanoes work and how to monitor their changing habits. Geologic mapping as well as studies of earthquake patterns and surface deformation associated with underground movement of magma have given scientists a better view of the inner structure and dynamics of active volcanoes. With the next decade, the time has come to focuses more on applying this knowledge toward reducing the risk from volcanic activity on a worldwide basis. 

  12. Subdiffusion of volcanic earthquakes

    CERN Document Server

    Abe, Sumiyoshi

    2016-01-01

    A comparative study is performed on volcanic seismicities at Mt.Eyjafjallajokull in Iceland and Mt. Etna in Sicily, Italy, from the viewpoint of science of complex systems, and the discovery of remarkable similarities between them regarding their exotic spatio-temporal properties is reported. In both of the volcanic seismicities as point processes, the jump probability distributions of earthquakes are found to obey the exponential law, whereas the waiting-time distributions follow the power law. In particular, a careful analysis is made about the finite size effects on the waiting-time distributions, and accordingly, the previously reported results for Mt. Etna [S. Abe and N. Suzuki, EPL 110, 59001 (2015)] are reinterpreted. It is shown that spreads of the volcanic earthquakes are subdiffusive at both of the volcanoes. The aging phenomenon is observed in the "event-time-averaged" mean-squared displacements of the hypocenters. A comment is also made on presence/absence of long term memories in the context of t...

  13. 1992-93 Results of geomorphological and field studies Volcanic Studies Program, Yucca Mountain Project

    Energy Technology Data Exchange (ETDEWEB)

    Wells, S.G.

    1993-10-01

    Field mapping and stratigraphic studies were completed of the Black Tank volcanic center, which represents the southwestern most eruptive center in the Cima volcanic field of California. The results of this mapping are presented. Contacts between volcanic units and geomorphic features were field checked, incorporating data from eight field trenches as well as several exposures along Black Tank Wash. Within each of the eight trenches, logs were measured and stratigraphic sections were described. These data indicate that three, temporally separate volcanic eruptions occurred at the Black Tank center. The field evidence for significant time breaks between each stratigraphic unit is the presence of soil and pavement-bounded unconformities.

  14. [The and beginnings of Chilean endocrinology in the 1920s].

    Science.gov (United States)

    Sánchez Delgado, Marcelo

    2016-01-01

    Rejuvenation was a chapter of critical importance for the worldwide development of endocrinology in the 1920s. This work explores the acceptance of these techniques in Chile. Starting in the late 19th century, the Chilean Medical Journal (Revista Médica de Chile) incorporated references to experiments with endocrine gland preparations that were being conducted in Europe at the time. An appropriation of the experiments by the Austrian Eugen Steinach began in 1920, with prominent figures such as the Italian professor Juan Noe Crevani and the young Chilean student Ottmar Wilhelm. Between 1922 and 1924, Wilhelm developed a series of experiments on dogs, bulls, pigs, rats and Welfare Board patients through the so-called Steinach operation, which consisted of the sectioning of the efferent channel in one of the testicles. Professor Noe's scientific patronage policy and Wilhelm's strategy of succession in the field led the latter to hold a chair in the new School of Medicine of Universidad de Concepci6n at the age of 25. From this position, the. figure of Wilhelm was fundamental for the development of a line of endocrinological research that was able to position Universidad de Concepci6n as a scientific development centre, which was strengthened by the arrival of another disciple of Steinach in Chile, the Latvian professor Alejandro Lipschütz. PMID:27363250

  15. Positive discrimination in education: Its justification and a Chilean example

    Science.gov (United States)

    Garcia-Huidobro, Juan Eduardo S.

    1994-05-01

    Educational policies in Latin America have centred on two main issues: raising the quality of education, and improving the equity of its distribution. Access to schooling was until recently at the heart of the debate, the degree of justice of the educational systems being measured by their capacity to enrol and retain the population. Attention is now concentrated on the strength of the cultural resources offered by schools and the effectiveness of provision. Learning is the priority of education policy. This article develops the theme of equity, examining the concept and describing a programme which focuses on improving the equity of the Chilean educational system. It is suggested that educational equity should no longer mean equality of access but equality of results. A just system therefore needs to concentrate on raising the quality of schools serving the poorest sectors of society. The Chilean "900 Schools Programme" is an example. Its aim was to raise levels of achievement by improving the learning of poor children from 1st to 4th grade in reading, writing and mathematics. To do so, it improved the school environment, textbooks and methodologies, and offered support to children outside school hours by the work of community monitors.

  16. Report on the 2010 Chilean earthquake and tsunami response

    Science.gov (United States)

    ,

    2011-01-01

    In July 2010, in an effort to reduce future catastrophic natural disaster losses for California, the American Red Cross coordinated and sent a delegation of 20 multidisciplinary experts on earthquake response and recovery to Chile. The primary goal was to understand how the Chilean society and relevant organizations responded to the magnitude 8.8 Maule earthquake that struck the region on February 27, 2010, as well as how an application of these lessons could better prepare California communities, response partners and state emergency partners for a comparable situation. Similarities in building codes, socioeconomic conditions, and broad extent of the strong shaking make the Chilean earthquake a very close analog to the impact of future great earthquakes on California. To withstand and recover from natural and human-caused disasters, it is essential for citizens and communities to work together to anticipate threats, limit effects, and rapidly restore functionality after a crisis. The delegation was hosted by the Chilean Red Cross and received extensive briefings from both national and local Red Cross officials. During nine days in Chile, the delegation also met with officials at the national, regional, and local government levels. Technical briefings were received from the President’s Emergency Committee, emergency managers from ONEMI (comparable to FEMA), structural engineers, a seismologist, hospital administrators, firefighters, and the United Nations team in Chile. Cities visited include Santiago, Talca, Constitución, Concepción, Talcahuano, Tumbes, and Cauquenes. The American Red Cross Multidisciplinary Team consisted of subject matter experts, who carried out special investigations in five Teams on the (1) science and engineering findings, (2) medical services, (3) emergency services, (4) volunteer management, and (5) executive and management issues (see appendix A for a full list of participants and their titles and teams). While developing this

  17. Volcanic Ash Nephelometer Probe Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Advanced dropsondes that could effectively be guided through atmospheric regions of interest such as volcanic plumes may enable unprecedented observations of...

  18. Volcanic Eruptions and Climate

    Science.gov (United States)

    Robock, A.

    2012-12-01

    Large volcanic eruptions inject sulfur gases into the stratosphere, which convert to sulfate aerosols with an e-folding residence time of about one year. The radiative and chemical effects of these aerosol clouds produce responses in the climate system. Observations and numerical models of the climate system show that volcanic eruptions produce global cooling and were the dominant natural cause of climate change for the past millennium, on timescales from annual to century. Major tropical eruptions produce winter warming of Northern Hemisphere continents for one or two years, while high latitude eruptions in the Northern Hemisphere weaken the Asian and African summer monsoon. The Toba supereruption 74,000 years ago caused very large climate changes, affecting human evolution. However, the effects did not last long enough to produce widespread glaciation. An episode of four large decadally-spaced eruptions at the end of the 13th century C.E. started the Little Ice Age. Since the Mt. Pinatubo eruption in the Philippines in 1991, there have been no large eruptions that affected climate, but the cumulative effects of small eruptions over the past decade had a small effect on global temperature trends. The June 13, 2011 Nabro eruption in Eritrea produced the largest stratospheric aerosol cloud since Pinatubo, and the most of the sulfur entered the stratosphere not by direct injection, but by slow lofting in the Asian summer monsoon circulation. Volcanic eruptions warn us that while stratospheric geoengineering could cool the surface, reducing ice melt and sea level rise, producing pretty sunsets, and increasing the CO2 sink, it could also reduce summer monsoon precipitation, destroy ozone, allowing more harmful UV at the surface, produce rapid warming when stopped, make the sky white, reduce solar power, perturb the ecology with more diffuse radiation, damage airplanes flying in the stratosphere, degrade astronomical observations, affect remote sensing, and affect

  19. Quaternary basaltic volcanism in the Payenia volcanic province, Argentina

    DEFF Research Database (Denmark)

    Søager, Nina

    Pleistocene times. These basalts mark the end of a period of shallow subduction of the Nazca slab beneath the Payenia province and volcanism in the Nevado volcanic field apparently followed the downwarping slab in a north-northwest direction ending in the Northern Segment. The northern Payenia basalts...

  20. New evidence about the subduction of the Copiapó ridge beneath South America, and its connection with the Chilean-Pampean flat slab, tracked by satellite GOCE and EGM2008 models

    Science.gov (United States)

    Álvarez, Orlando; Gimenez, Mario; Folguera, Andres; Spagnotto, Silvana; Bustos, Emilce; Baez, Walter; Braitenberg, Carla

    2015-11-01

    Satellite-only gravity measurements and those integrated with terrestrial observations provide global gravity field models of unprecedented precision and spatial resolution, allowing the analysis of the lithospheric structure. We used the model EGM2008 (Earth Gravitational Model) to calculate the gravity anomaly and the vertical gravity gradient in the South Central Andes region, correcting these quantities by the topographic effect. Both quantities show a spatial relationship between the projected subduction of the Copiapó aseismic ridge (located at about 27°-30° S), its potential deformational effects in the overriding plate, and the Ojos del Salado-San Buenaventura volcanic lineament. This volcanic lineament constitutes a projection of the volcanic arc toward the retroarc zone, whose origin and development were not clearly understood. The analysis of the gravity anomalies, at the extrapolated zone of the Copiapó ridge beneath the continent, shows a change in the general NNE-trend of the Andean structures to an ENE-direction coincident with the area of the Ojos del Salado-San Buenaventura volcanic lineament. This anomalous pattern over the upper plate is interpreted to be linked with the subduction of the Copiapó ridge. We explore the relation between deformational effects and volcanism at the northern Chilean-Pampean flat slab and the collision of the Copiapó ridge, on the basis of the Moho geometry and elastic thicknesses calculated from the new satellite GOCE data. Neotectonic deformations interpreted in previous works associated with volcanic eruptions along the Ojos del Salado-San Buenaventura volcanic lineament is interpreted as caused by crustal doming, imprinted by the subduction of the Copiapó ridge, evidenced by crustal thickening at the sites of ridge inception along the trench. Finally, we propose that the Copiapó ridge could have controlled the northern edge of the Chilean-Pampean flat slab, due to higher buoyancy, similarly to the control

  1. Isotopic compositions of sulphates and nitrates from the Chilean nitrate deposits, evidence for concentration and fractionation of parental brines

    International Nuclear Information System (INIS)

    Isotopic compositions of nitrates (δ15N and δ18O) in caliche samples from the Chilean nitrate deposits are similar to recent values reported for nitrate associated to atmospheric N deposition. δ34S and δ18O of sulphate minerals present in the nitrate ores show similar values to those of continental evaporites in the area of Atacama, which suggest volcanic and hydrothermal sources. The sulphate isotope compositions display positive correlation trends (between δ34S and δ18OSO4) reflecting a reservoir effect due to fractionation related to precipitation. This effect has been clearly observed for sulphur and oxygen from sedimentary to bedrock caliche samples. Ore-grade bedrock caliche (mostly nitratine-halite mixtures filling veins) shows lower δ34S and δ18O values than sedimentary caliche (acting as wall rock). This suggests the concentration and fractionation of brines by repeated processes of evaporation and precipitation. Saline compounds of different origins present in the Neogene Atacama Desert were transported by the hydrological system towards the lower endorheic areas. As a result, saline minerals (mostly nitrates, chlorides and sulphates) precipitated filling the porosity and fractures of previous rocks (author)

  2. Volcan Reventador's Unusual Umbrella

    Science.gov (United States)

    Chakraborty, P.; Gioia, G.; Kieffer, S. W.

    2005-12-01

    In the past two decades, field observations of the deposits of volcanoes have been supplemented by systemmatic, and sometimes, opportunistic photographic documentation. Two photographs of the umbrella of the December 3, 2002 eruption of Volcan Reventador, Ecuador, reveal a prominently scalloped umbrella that is unlike any umbrella previously documented on a volcanic column. The material in the umbrella was being swept off a descending pyroclastic flow, and was, therefore, a co-ignimbrite cloud. We propose that the scallops are the result of a turbulent Rayleigh-Taylor (RT) instability with no precedents in volcanology. We ascribe the rare loss of buoyancy that drives this instability to the fact that the Reventador column fed on a cool co-ignimbrite cloud. On the basis of the observed wavelength of the scallops, we estimate a value for the eddy viscosity of the umbrella of 4000 ~m2/s. This value is consistent with a previously obtained lower bound (200 ~m2/s, K. Wohletz, priv. comm., 2005). We do not know the fate of the material in the umbrella subsequent to the photos. The analysis suggests that the umbrella was negatively buoyant. Field work on the co-ignimbrite deposits might reveal whether or not the material reimpacted, and if so, where and whether or not this material was involved in the hazardous flows that affected the main oil pipeline across Ecuador.

  3. Uranium series, volcanic rocks

    Science.gov (United States)

    Vazquez, Jorge A.

    2014-01-01

    Application of U-series dating to volcanic rocks provides unique and valuable information about the absolute timing of crystallization and differentiation of magmas prior to eruption. The 238U–230Th and 230Th-226Ra methods are the most commonly employed for dating the crystallization of mafic to silicic magmas that erupt at volcanoes. Dates derived from the U–Th and Ra–Th methods reflect crystallization because diffusion of these elements at magmatic temperatures is sluggish (Cherniak 2010) and diffusive re-equilibration is insignificant over the timescales (less than or equal to 10^5 years) typically associated with pre-eruptive storage of nearly all magma compositions (Cooper and Reid 2008). Other dating methods based on elements that diffuse rapidly at magmatic temperatures, such as the 40Ar/39Ar and (U–Th)/He methods, yield dates for the cooling of magma at the time of eruption. Disequilibrium of some short-lived daughters of the uranium series such as 210Po may be fractionated by saturation of a volatile phase and can be employed to date magmatic gas loss that is synchronous with volcanic eruption (e.g., Rubin et al. 1994).

  4. Volcanic Eruptions and Climate

    Science.gov (United States)

    LeGrande, Allegra N.; Anchukaitis, Kevin J.

    2015-01-01

    Volcanic eruptions represent some of the most climatically important and societally disruptive short-term events in human history. Large eruptions inject ash, dust, sulfurous gases (e.g. SO2, H2S), halogens (e.g. Hcl and Hbr), and water vapor into the Earth's atmosphere. Sulfurous emissions principally interact with the climate by converting into sulfate aerosols that reduce incoming solar radiation, warming the stratosphere and altering ozone creation, reducing global mean surface temperature, and suppressing the hydrological cycle. In this issue, we focus on the history, processes, and consequences of these large eruptions that inject enough material into the stratosphere to significantly affect the climate system. In terms of the changes wrought on the energy balance of the Earth System, these transient events can temporarily have a radiative forcing magnitude larger than the range of solar, greenhouse gas, and land use variability over the last millennium. In simulations as well as modern and paleoclimate observations, volcanic eruptions cause large inter-annual to decadal-scale changes in climate. Active debates persist concerning their role in longer-term (multi-decadal to centennial) modification of the Earth System, however.

  5. Terrestrial volcanism in space and time

    Science.gov (United States)

    Simkin, Tom

    1993-01-01

    A survey is presented of current volcanic activity around the world and of dated volcanism over the past 10,000 yrs. The patterns in the data are described. The hazard presented by volcanism is briefly examined.

  6. Sr-Nd isotope changes of late cretaceous to early miocene volcanic rocks in central Chile (33oS)

    International Nuclear Information System (INIS)

    A longitudinal depression, the Central Valley, separates the Coast Range from the Andean Cordillera in central Chile. It contains volcanic and volcaniclastic rocks of Late Cretaceous to Tertiary age deposited in a continental environment, and partly eroded Tertiary volcanic complexes. The age of the rocks at the northern end of the Central Valley and their grouping in formations have been a long-standing controversy in Chilean geology (Thomas, 1958; Aguirre, 1960; Drake et al., 1976; Vergara and Drake, 1979; Thiele, 1980; Moscoso et al., 1982; Gana and Wall, 1997; Lopez-Escobar and Vergara, 1997; Selles, 1999). Here, we report new 40Ar/39Ar data and Sr-Nd isotope ratios for lavas, pyroclastic flows and associated subvolcanic rocks from this part of central Chile (au)

  7. Creating stability in constant uncertainty : dealing with crisis in the Chilean aquaculture industry

    OpenAIRE

    Amundsen, Vilde Steiro

    2015-01-01

    This thesis is the result of a fieldwork conducted in Fish Inc., a Chilean branch of a Norwegian-owned company dealing with equipment for fish farming. The Chilean aquaculture industry has since the sanitary and financial crisis of 2007 experienced a constant unpredictability, with extreme fluctuation between incredible upswings and crashing downturns. The instability and uncertainty of the industry has generated the necessity of creating a sense of continuity for employees in dealing with th...

  8. BTX abatement using Chilean natural zeolite: the role of Brønsted acid sites

    OpenAIRE

    Alejandro, S.; Valdés, Héctor; Manero, Marie-Hélène; Zaror, Claudio A.

    2012-01-01

    In wastewater treatment facilities, air quality is not only affected by conventional unpleasant odour compounds; toxic volatile organic compounds (VOCs) are also found. In this study, the adsorptive capacity of Chilean natural zeolite toward VOC removal was evaluated. Moreover, the influence of zeolite chemical surface properties on VOC elimination was also investigated. Three modified zeolite samples were prepared from a natural Chilean zeolite (53% clinoptilolite, 40% mordenite and 7% quart...

  9. Strengthening early math skills in preschoolers, a Chilean study

    Directory of Open Access Journals (Sweden)

    Rosario Ortega

    2011-05-01

    Full Text Available The article describes the positive effect in an intervention programbased on number comprehension in early math skill levels that Chileanpreschoolers present in the relational and numerical skill areas evaluated with the Test of Early Mathematics Assessment Utrecht (TEMT-U, the Spanish version of the Utrecht Early Numeracy Test. The study reveals that there are significant differences in the early math skills levels among those groups subjected to thistype of program and those that in the same period of time were only influenced by the content and activities of the traditional curriculum sequence in the Chilean school population. There are positive effects in the program regardless of the educational level that children attend. There are also relational or skillsPiagetian that show higher achievement levels. The results prove that there are no differences in mathematical literacy levels between boys and girls, contrary to what is observed in later years.

  10. Chilean prosopis mesocarp flour: phenolic profiling and antioxidant activity.

    Science.gov (United States)

    Schmeda-Hirschmann, Guillermo; Quispe, Cristina; Soriano, Maria Del Pilar C; Theoduloz, Cristina; Jiménez-Aspée, Felipe; Pérez, Maria Jorgelina; Cuello, Ana Soledad; Isla, Maria Inés

    2015-04-17

    In South America, the mesocarp flour of Prosopis species plays a prominent role as a food resource in arid areas. The aim of this work was the characterization of the phenolic antioxidants occurring in the pod mesocarp flour of Chilean Prosopis. Samples were collected in the Copiapo, Huasco and Elqui valleys from the north of Chile. The samples of P. chilensis flour exhibited a total phenolic content ranging between 0.82-2.57 g gallic acid equivalents/100 g fresh flour weight. The highest antioxidant activity, measured by the DPPH assay, was observed for samples from the Huasco valley. HPLC-MS/MS analysis allowed the tentative identification of eight anthocyanins and 13 phenolic compounds including flavonol glycosides, C-glycosyl flavones and ellagic acid derivatives. The antioxidant activity and the phenolic composition in the flour suggest that this ancient South American resource may have potential as a functional food.

  11. Chilean Prosopis Mesocarp Flour: Phenolic Profiling and Antioxidant Activity

    Directory of Open Access Journals (Sweden)

    Guillermo Schmeda-Hirschmann

    2015-04-01

    Full Text Available In South America, the mesocarp flour of Prosopis species plays a prominent role as a food resource in arid areas. The aim of this work was the characterization of the phenolic antioxidants occurring in the pod mesocarp flour of Chilean Prosopis. Samples were collected in the Copiapo, Huasco and Elqui valleys from the north of Chile. The samples of P. chilensis flour exhibited a total phenolic content ranging between 0.82–2.57 g gallic acid equivalents/100 g fresh flour weight. The highest antioxidant activity, measured by the DPPH assay, was observed for samples from the Huasco valley. HPLC-MS/MS analysis allowed the tentative identification of eight anthocyanins and 13 phenolic compounds including flavonol glycosides, C-glycosyl flavones and ellagic acid derivatives. The antioxidant activity and the phenolic composition in the flour suggest that this ancient South American resource may have potential as a functional food.

  12. Justified Ilegality?: Controlled clientelism by the Chilean administration

    Directory of Open Access Journals (Sweden)

    Marcelo Moriconi Bezerra

    2011-07-01

    Full Text Available The Chilean civil service is considered one of the most efficient in Latin America. However, different studies describe the informal institutions that operate between the Legislative Power and the bureaucracy to fill positions in the public administration. Although some of these clientelistic practices are against the law, they have been accepted and defended in both the political and scientific spheres. Legality is not considered an important value if certain indexes have a positive development. In this context, it is important to study how corruption and clientelism have been ignored, or hidden, through political discourses and technical reports about the situation of bureaucracy. All of this allows a better understanding of why after 20 years of administrative reforms there are damaging practices which negatively affect democracy that have not been eradicated.

  13. Chilean prosopis mesocarp flour: phenolic profiling and antioxidant activity.

    Science.gov (United States)

    Schmeda-Hirschmann, Guillermo; Quispe, Cristina; Soriano, Maria Del Pilar C; Theoduloz, Cristina; Jiménez-Aspée, Felipe; Pérez, Maria Jorgelina; Cuello, Ana Soledad; Isla, Maria Inés

    2015-01-01

    In South America, the mesocarp flour of Prosopis species plays a prominent role as a food resource in arid areas. The aim of this work was the characterization of the phenolic antioxidants occurring in the pod mesocarp flour of Chilean Prosopis. Samples were collected in the Copiapo, Huasco and Elqui valleys from the north of Chile. The samples of P. chilensis flour exhibited a total phenolic content ranging between 0.82-2.57 g gallic acid equivalents/100 g fresh flour weight. The highest antioxidant activity, measured by the DPPH assay, was observed for samples from the Huasco valley. HPLC-MS/MS analysis allowed the tentative identification of eight anthocyanins and 13 phenolic compounds including flavonol glycosides, C-glycosyl flavones and ellagic acid derivatives. The antioxidant activity and the phenolic composition in the flour suggest that this ancient South American resource may have potential as a functional food. PMID:25898415

  14. Helicobacter pylori infection and gastrointestinal symptoms on Chilean pregnant women

    Directory of Open Access Journals (Sweden)

    Gina Ferrer Poveda

    2014-07-01

    Full Text Available Objective: the aim of this research was to determine the prevalence of Helicobacter pylori infection on Chilean pregnant women and its relationship with the appearance and severity of hyperemesis and dyspepsia. Methods: quantitative study of prevalence in a transversal cut with variable analysis. The sample was taken from 274 Chilean pregnant women from the Bío Bío province through vein puncture between June and December, 2005. Pregnant women were informed of this study, interviewed and signed an informed consent. The samples were processed using ImmunoComb II Helicobacter pylori IgG kit. Statistical analysis was performed by means of the Statistical Package for Social Sciences (SPSS Program. Results: out of the total number of pregnant women, 68.6% showed infection by Helicobacter pylori. 79.6% of the total sample had symptoms of dyspepsia, and 72.5% of this group presented Helicobacter pylori infection. 12.4% showed pregnancy hyperemesis; among them, 79.4% were infected with Helicobacter pylori. 73.4% of the pregnant women that showed gastric discomfort during the first three months had Helicobacter pylori infection. 53.7% of them continued with gastric discomfort after the first three months; of those, 95.8% were infected. Helicobacter pylori infection was present only in 1.5% of pregnant women without gastric discomfort. Conclusion: both, gastric discomfort of pregnant women and the continuity of severe symptoms of dyspepsia and hyperemesis after the first three months of gestation are significantly correlated with Helicobacter pylori infection.

  15. VOCALS-CUpEx: the Chilean Upwelling Experiment

    Science.gov (United States)

    Garreaud, R. D.; Rutllant, J. A.; Muñoz, R. C.; Rahn, D. A.; Ramos, M.; Figueroa, D.

    2011-03-01

    The VAMOS Ocean-Cloud-Atmosphere-Land Study Regional Experiment (VOCALS-REx) was a major field experiment conducted in spring of 2008 off southern Peru and northern Chile, aimed at better understanding the coupled climate systems of the southeast Pacific. Because of logistical constrains, the coastal area around 30° S was not sampled during VOCALS-REx. This area not only marks the poleward edge of the subtropical stratocumulus cloud regime (thus acting as a source of transient disturbances) but is also one of the most active upwelling centers and source of surface ocean kinetic energy along the Chilean coast. To fill such an observational gap, a small, brief, but highly focused field experiment was conducted in late spring 2009 in the near-shore region around 30° S. The Chilean Upwelling Experiment (CUpEx) was endorsed by VOCALS as a regional component. CUpEx included long-term monitoring, an intensive two-week field campaign and off-shore research flights. Our goal was to obtain an atmospheric/oceanic dataset with enough temporal and spatial coverage to be able to document (a) the mean diurnal cycles of the lower-troposphere and upper-ocean in a region of complex topography and coastline geometry, and (b) the ocean-atmosphere response to the rapid changes in coastal winds from strong, upwelling-favorable equatorward flow (southerly winds) to downwelling-favorable poleward flow (northerly winds). In this paper we describe the measurement platforms and sampling strategy, and provide an observational overview, highlighting some key mean-state and transient features.

  16. Indo-European and Asian origins for Chilean and Pacific chickens revealed by mtDNA.

    Science.gov (United States)

    Gongora, Jaime; Rawlence, Nicolas J; Mobegi, Victor A; Jianlin, Han; Alcalde, Jose A; Matus, Jose T; Hanotte, Olivier; Moran, Chris; Austin, Jeremy J; Ulm, Sean; Anderson, Atholl J; Larson, Greger; Cooper, Alan

    2008-07-29

    European chickens were introduced into the American continents by the Spanish after their arrival in the 15th century. However, there is ongoing debate as to the presence of pre-Columbian chickens among Amerindians in South America, particularly in relation to Chilean breeds such as the Araucana and Passion Fowl. To understand the origin of these populations, we have generated partial mitochondrial DNA control region sequences from 41 native Chilean specimens and compared them with a previously generated database of approximately 1,000 domestic chicken sequences from across the world as well as published Chilean and Polynesian ancient DNA sequences. The modern Chilean sequences cluster closely with haplotypes predominantly distributed among European, Indian subcontinental, and Southeast Asian chickens, consistent with a European genetic origin. A published, apparently pre-Columbian, Chilean specimen and six pre-European Polynesian specimens also cluster with the same European/Indian subcontinental/Southeast Asian sequences, providing no support for a Polynesian introduction of chickens to South America. In contrast, sequences from two archaeological sites on Easter Island group with an uncommon haplogroup from Indonesia, Japan, and the Philippines [corrected] and may represent a genetic signature of an early Polynesian dispersal. Modeling of the potential marine carbon contribution to the Chilean archaeological specimen casts further doubt on claims for pre-Columbian chickens, and definitive proof will require further analyses of ancient DNA sequences and radiocarbon and stable isotope data from archaeological excavations within both Chile and Polynesia. PMID:18663216

  17. Friction in volcanic environments

    Science.gov (United States)

    Kendrick, Jackie E.; Lavallée, Yan

    2016-04-01

    Volcanic landscapes are amongst the most dynamic on Earth and, as such, are particularly susceptible to failure and frictional processes. In rocks, damage accumulation is frequently accompanied by the release of seismic energy, which has been shown to accelerate in the approach to failure on both a field and laboratory scale. The point at which failure occurs is highly dependent upon strain-rate, which also dictates the slip-zone properties that pertain beyond failure, in scenarios such as sector collapse and pyroclastic flows as well as the ascent of viscous magma. High-velocity rotary shear (HVR) experiments have provided new opportunities to overcome the grand challenge of understanding faulting processes during volcanic phenomena. Work on granular ash material demonstrates that at ambient temperatures, ash gouge behaves according to Byerlee's rule at low slip velocities, but is slip-weakening, becoming increasingly lubricating as slip ensues. In absence of ash along a slip plane, rock-rock friction induces cataclasis and heating which, if sufficient, may induce melting (producing pseudotachylyte) and importantly, vesiculation. The viscosity of the melt, so generated, controls the subsequent lubrication or resistance to slip along the fault plane thanks to non-Newtonian suspension rheology. The shear-thinning behaviour and viscoelasticity of frictional melts yield a tendency for extremely unstable slip, and occurrence of frictional melt fragmentation. This velocity-dependence acts as an important feedback mechanism on the slip plane, in addition to the bulk composition, mineralogy and glass content of the magma, that all influence frictional behaviour. During sector collapse events and in pyroclastic density currents it is the frictional properties of the rocks and ash that, in-part, control the run-out distance and associated risk. In addition, friction plays an important role in the eruption of viscous magmas: In the conduit, the rheology of magma is integral

  18. Recurrence models of volcanic events

    International Nuclear Information System (INIS)

    An assessment of the risk of future volcanism has been conducted for isolation of high-level radioactive waste at the potential Yucca Mountain site in southern Nevada. Volcanism studies for the Yucca Mountain Site Characterization Project have progressed to a sufficient degree that it is now prudent to work toward concluding aspects of the work. An advantage of a probabilistic approach to volcanic risk is that it assigns a structured formalism to the problem. This formalism subdivides a complex issue into logical sections. The significance of uncertainty or differences in scientific opinion concerning volcanism issues can be tested for each section of a probabilistic problem. The perspective for making judgement of significance for volcanism studied are the regulatory requirements for assessing the suitability of the potential Yucca Mountain site. This paper attempts to begin the process of helping establish the probabilistic framework for making those judgement. There are three objectives. First, the authors describe the tripartite probability used to define the risk of volcanism and the geologic assumptions required for the probability model. Second, the authors examine and define the first part of this probability, the recurrence of volcanic events. Studies are reviewed from the volcanological literature where time-volume behavior of volcanic centers and fields have been evaluated. These evaluations include both conventional statistical analysis of time-series of volcanic events and applications using newly developing concepts of fractal analysis and deterministic chaos. Third, the authors tabulate past calculations and derive new values for the recurrence of volcanic events using a simple Poison model

  19. Rapid response of a hydrologic system to volcanic activity: Masaya volcano, Nicaragua

    Science.gov (United States)

    Pearson, S.C.P.; Connor, C.B.; Sanford, W.E.

    2008-01-01

    Hydrologic systems change in response to volcanic activity, and in turn may be sensitive indicators of volcanic activity. Here we investigate the coupled nature of magmatic and hydrologic systems using continuous multichannel time series of soil temperature collected on the flanks of Masaya volcano, Nicaragua, one of the most active volcanoes in Central America. The soil temperatures were measured in a low-temperature fumarole field located 3.5 km down the flanks of the volcano. Analysis of these time series reveals that they respond extremely rapidly, on a time scale of minutes, to changes in volcanic activity also manifested at the summit vent. These rapid temperature changes are caused by increased flow of water vapor through flank fumaroles during volcanism. The soil temperature response, ~5 °C, is repetitive and complex, with as many as 13 pulses during a single volcanic episode. Analysis of the frequency spectrum of these temperature time series shows that these anomalies are characterized by broad frequency content during volcanic activity. They are thus easily distinguished from seasonal trends, diurnal variations, or individual rainfall events, which triggered rapid transient increases in temperature during 5% of events. We suggest that the mechanism responsible for the distinctive temperature signals is rapid change in pore pressure in response to magmatism, a response that can be enhanced by meteoric water infiltration. Monitoring of distal fumaroles can therefore provide insight into coupled volcanic-hydrologic-meteorologic systems, and has potential as an inexpensive monitoring tool.

  20. Report on the 2010 Chilean earthquake and tsunami response

    Science.gov (United States)

    ,

    2011-01-01

    In July 2010, in an effort to reduce future catastrophic natural disaster losses for California, the American Red Cross coordinated and sent a delegation of 20 multidisciplinary experts on earthquake response and recovery to Chile. The primary goal was to understand how the Chilean society and relevant organizations responded to the magnitude 8.8 Maule earthquake that struck the region on February 27, 2010, as well as how an application of these lessons could better prepare California communities, response partners and state emergency partners for a comparable situation. Similarities in building codes, socioeconomic conditions, and broad extent of the strong shaking make the Chilean earthquake a very close analog to the impact of future great earthquakes on California. To withstand and recover from natural and human-caused disasters, it is essential for citizens and communities to work together to anticipate threats, limit effects, and rapidly restore functionality after a crisis. The delegation was hosted by the Chilean Red Cross and received extensive briefings from both national and local Red Cross officials. During nine days in Chile, the delegation also met with officials at the national, regional, and local government levels. Technical briefings were received from the President’s Emergency Committee, emergency managers from ONEMI (comparable to FEMA), structural engineers, a seismologist, hospital administrators, firefighters, and the United Nations team in Chile. Cities visited include Santiago, Talca, Constitución, Concepción, Talcahuano, Tumbes, and Cauquenes. The American Red Cross Multidisciplinary Team consisted of subject matter experts, who carried out special investigations in five Teams on the (1) science and engineering findings, (2) medical services, (3) emergency services, (4) volunteer management, and (5) executive and management issues (see appendix A for a full list of participants and their titles and teams). While developing this

  1. Biogeochemistry and nitrogen cycling in an Arctic, volcanic ecosystem

    Science.gov (United States)

    Fogel, M. L.; Benning, L.; Conrad, P. G.; Eigenbrode, J.; Starke, V.

    2007-12-01

    As part of a study on Mars Analogue environments, the biogeochemistry of Sverrefjellet Volcano, Bocfjorden, Svalbard, was conducted and compared to surrounding glacial, thermal spring, and sedimentary environments. An understanding of how nitrogen might be distributed in a landscape that had extinct or very cold adapted, slow- growing extant organisms should be useful for detecting unknown life forms. From high elevations (900 m) to the base of the volcano (sea level), soil and rock ammonium concentrations were uniformly low, typically less than 1- 3 micrograms per gm of rock or soil. In weathered volcanic soils, reduced nitrogen concentrations were higher, and oxidized nitrogen concentrations lower. The opposite was found in a weathered Devonian sedimentary soil. Plants and lichens growing on volcanic soils have an unusually wide range in N isotopic compositions from -5 to +12‰, a range rarely measured in temperate ecosystems. Nitrogen contents and isotopic compositions of volcanic soils and rocks were strongly influenced by the presence or absence of terrestrial herbivores or marine avifauna with higher concentrations of N and elevated N isotopic compositions occurring as patches in areas immediately influenced by reindeer, Arctic fox ( Alopex lagopus), and marine birds. Because of the extreme conditions in this area, ephemeral deposition of herbivore feces results in a direct and immediate N pulses into the ecosystem. The lateral extent and distribution of marine- derived nitrogen was measured on a landscape scale surrounding an active fox den. Nitrogen was tracked from the bones of marine birds to soil to vegetation. Because of extreme cold, slow biological rates and nitrogen cycling, a mosaic of N patterns develops on the landscape scale.

  2. Closer look at lunar volcanism

    International Nuclear Information System (INIS)

    Although the American Apollo and Soviet Luna missions concentrated on mare basalt samples, major questions remain about lunar volcanism. Lunar field work will be indispensable for resolving the scientific questions about ages, compositions, and eruption processes of lunar volcanism. From a utilitarian standpoint, a better knowledge of lunar volcanism will also yield profitable returns in lunar base construction (e.g., exploitation of rille or lava-tube structures) and in access to materials such as volatile elements, pure glass, or ilmenite for lunar industry

  3. Io. [theories concerning volcanic activity

    Science.gov (United States)

    Johnson, T. V.; Soderblom, L. A.

    1983-01-01

    A report on the continuing investigation of Io is presented. Gravitational resonance is discussed as the cause of Io's volcanism, and the volcanic activity is explained in terms of sulfur chemistry. Theories concerning the reasons for the two main types of volcanic eruptions on Io are advanced and correlated with geographical features of the satellite. The sulfur and silicate models of the calderas are presented, citing the strengths and weaknesses of each. Problems of the gravitational resonance theory of Io's heat source are then described. Finally, observations of Io planned for the Galileo mission are summarized.

  4. Hazardous indoor CO2 concentrations in volcanic environments.

    Science.gov (United States)

    Viveiros, Fátima; Gaspar, João L; Ferreira, Teresa; Silva, Catarina

    2016-07-01

    Carbon dioxide is one of the main soil gases released silently and permanently in diffuse degassing areas, both in volcanic and non-volcanic zones. In the volcanic islands of the Azores (Portugal) several villages are located over diffuse degassing areas. Lethal indoor CO2 concentrations (higher than 10 vol %) were measured in a shelter located at Furnas village, inside the caldera of the quiescent Furnas Volcano (S. Miguel Island). Hazardous CO2 concentrations were detected not only underground, but also at the ground floor level. Multivariate regression analysis was applied to the CO2 and environmental time series recorded between April 2008 and March 2010 at Furnas village. The results show that about 30% of the indoor CO2 variation is explained by environmental variables, namely barometric pressure, soil water content and wind speed. The highest indoor CO2 concentrations were recorded during bad weather conditions, characterized by low barometric pressure together with rainfall periods and high wind speed. In addition to the spike-like changes observed on the CO2 time series, long-term oscillations were also identified and appeared to represent seasonal variations. In fact, indoor CO2 concentrations were higher during winter period when compared to the dry summer months. Considering the permanent emission of CO2 in various volcanic regions of the world, CO2 hazard maps are crucial and need to be accounted by the land-use planners and authorities.

  5. Chilean Teachers Begin Exchange Program Visit in Magdalena

    Science.gov (United States)

    2007-01-01

    . Kelly. The Chilean teachers are visiting Magdalena while they are on their Southern Hemisphere summer vacation, and Magdalena's schools are in session. Two Magdalena teachers, Joleen Welborn and Sandra Montoya, will visit San Pedro in June, while they are on summer vacation and the Chilean schools will be in session. Dr. Eduardo Hardy, the AUI/NRAO representative in Chile, will accompany the Chilean teachers on their visit, which has been coordinated by Harrison. "ALMA is a groundbreaking example of the type of international cooperation that marks the future of astronomy. We are especially pleased to sponsor a program that brings together two communities that both enjoy proximity to world-class astronomical research facilities," said Dr. Fred K.Y. Lo, NRAO Director. "While separated by many miles, San Pedro de Atacama and Magdalena have much in common. Both are small communities in high desert environments, and both are next to telescopes where the world's astronomers will be making many exciting discoveries in the coming decades. Bringing these two communities together will advance education and international understanding," Harrison said. The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

  6. Coevolution of volcanic catchments in Japan

    Science.gov (United States)

    Yoshida, Takeo; Troch, Peter A.

    2016-03-01

    Present-day landscapes have evolved over time through interactions between the prevailing climates and geological settings. Understanding the linkage between spatial patterns of landforms, soils, and vegetation in landscapes and their hydrological response is critical to make quantitative predictions in ungaged basins. Catchment coevolution is a theoretical framework that seeks to formulate hypotheses about the mechanisms and conditions that determine the historical development of catchments and how such evolution affects their hydrological response. In this study, we selected 14 volcanic catchments of different ages (from 0.225 to 82.2 Ma) in Japan. We derived indices of landscape properties (drainage density and slope-area relationship) as well as hydrological response (annual water balance, baseflow index, and flow-duration curves) and examined their relation with catchment age and climate (through the aridity index). We found a significant correlation between drainage density and baseflow index with age, but not with climate. The intra-annual flow variability was also significantly related to catchments age. Younger catchments tended to have lower peak flows and higher low flows, while older catchments exhibited more flashy runoff. The decrease in baseflow with catchment age is consistent with the existing hypothesis that in volcanic landscapes the major flow pathways change over time from deep groundwater flow to shallow subsurface flow. The drainage density of our catchments decreased with age, contrary to previous findings in a set of similar, but younger volcanic catchments in the Oregon Cascades, in which drainage density increased with age. In that case, older catchments were thought to show more landscape incision due to increasing near-surface lateral flow paths. Our results suggests two competing hypotheses on the evolution of drainage density in mature catchments. One is that as catchments continue to age, the hydrologically active channels retreat

  7. Volcanology: Volcanic bipolar disorder explained

    Science.gov (United States)

    Jellinek, Mark

    2014-02-01

    Eruptions come in a range of magnitudes. Numerical simulations and laboratory experiments show that rare, giant super-eruptions and smaller, more frequent events reflect a transition in the essential driving forces for volcanism.

  8. Streamflow responses to Chilean Megathrust earthquakes during the 20th and 21st centuries

    Science.gov (United States)

    Mohr, C.; Manga, M.; Wang, C. Y.; Korup, O.

    2015-12-01

    Coseismic static stress and dynamic stresses generated by propagating seismic waves cause responses in hydrological systems. Such responses include changes in the water level, hydrochemistry and streamflow discharge. Earthquake effects on hydrological systems provide a means to study the interaction between stress changes and regional hydrology, which is otherwise rarely possible. Chile is a country of frequent and large earthquakes and thus provides abundant opportunities to study such interactions and processes. Here we present streamflow responses to several Chilean Megathrust earthquakes, including the 1943 Mw 8.1 Coquimbo, 1950 Mw 8.2 Antofagasta, 1960 Mw 9.5 Valdivia, 1985 Mw 8.0 Valparaiso, 1995 Mw 8.0 Antofagasta, 2010 Mw 8.8 Maule, and the 2014 Mw 8.2 Iquique earthquakes. The stream gauges (n=716) are scattered across Chile, from the Altiplano in the North to Tierra del Fuego in the South. The network thus covers the Andes mountain ranges, the central valley, the Coastal Mountain ranges and (mainly in the more southern parts) the Coastal flats. We combine empirical magnitude-distance relationships, tree-based machine learning tools, and process-based modeling to characterize responses. We first assess the streamflow anomalies and relate these to environmental factors including geology, topography, altitude, soil and vegetation. We then apply 1D-groundwater flow modeling to selected catchments in order to test competing hypotheses for the origin of streamflow changes. We show that the responses of streamflow were heterogeneous, both in sign (decreases and increases in discharge) and in magnitude.

  9. Chemical metrology, strategic job for the Chilean Nuclear Energy Commission

    International Nuclear Information System (INIS)

    The National Standardization Institute's (INN) Metrology unit prepared a study in 1996 to evaluate the impact of metrological activity in Chile. This study was based on a survey of the supply and demand of metrological services and on studies of the behavior of the production system and technological services in Chile during the period 1990-1996. With the information obtained in this study the economic impact resulting from the lack of a national metrology system could be evaluated. This impact was estimated to be a 5% loss in gross national product equal to 125-500 million dollars because of direct product rejection in the mining, fisheries, agricultural and manufacturing sectors. Chemical measurements are responsible for 50% of these losses. In response to this need and coordinated by the INN, a metrological network of reference laboratories began to operate in 1997 for the principal physical magnitudes (mass, temperature, longitude and force) and a CORFO-FDI project began in 2001 that includes the chemical magnitudes. The Chilean Nuclear Energy Commission, aware of the problem's importance and the amount of economic damage that the country may suffer, as a result of these deficiencies, has formed a Chemical Metrology Unit to provide technical support. It aims to raise the standards of local analytical laboratories by providing international recognition to the export sector. Nuclear analytical techniques are used as reference methods. This work describes the laboratories that are included in this Chemical Metrology Unit and the historical contribution to the development of local analytical chemistry. The national and international projects are described together with the publications they have generated. The quality assurance program applied to the laboratories is described as well, which has led to the accreditation of the analytical chemical assays. The procedures used for validation and calculation of uncertain nuclear methodologies are described together with

  10. Dental fluorosis in Chilean children: evaluation of risk factors.

    Science.gov (United States)

    Villa, A E; Guerrero, S; Icaza, G; Villalobos, J; Anabalón, M

    1998-10-01

    The purpose of this case-control study was to determine the association between very-mild-to-moderate enamel fluorosis and exposure during early childhood to fluoridated water, mainly through ingestion of powdered milk. Analysis was performed on 136 residents of the optimally fluoridated community of San Felipe in the Chilean Fifth Region, who were categorised into one of three groups according to their age when water fluoridation was introduced in 1986: Group I was born after 1986; Group II was 16-24 months old in 1986; and Group III was >24 months of age. The case and control subjects were selected on the basis of a clinical examination given in July 1996. Dean's scoring system was used to determine fluorosis status. Risk factor exposure was ascertained by a questionnaire used in interviews with mothers of participating children. Logistic regression analysis, after adjustment for confounding variables, revealed that very-mild-to-moderate enamel fluorosis of permanent central maxillary incisors (CMI) was strongly associated both with the age of the subjects when water fluoridation began and with breast-feeding duration for children belonging to Group I. Subjects in Group I were 20.44 times more likely (95% CI: 5.00-93.48) to develop CMI fluorosis than children who were older than 24 months (Group III) when fluoridation began. Subjects who were between 16 and 24 months old when water fluoridation began were 4.15 times more likely (95% CI: 1.05-16.43) to have CMI fluorosis than children older than 24 months. An inverse association was found with breastfeeding duration (OR=0.86, 95% CI: 0.75-0.98) among Group I subjects but not in Groups II and III. Results obtained suggest that the current fluoride concentration in drinking water may be contributing to fluorosis. Further studies will be necessary to determine the relative competing risks of dental fluorosis and dental caries in Chilean children in order to establish the most appropriate water fluoridation level in

  11. Volcanic Zone, New Zealand

    Directory of Open Access Journals (Sweden)

    Graham J. Weir

    2001-01-01

    Full Text Available A conceptual model of the Taupo Volcanic Zone (TVZ is developed, to a depth of 25 km, formed from three constant density layers. The upper layer is formed from eruption products. A constant rate of eruption is assumed, which eventually implies a constant rate of extension, and a constant rate of volumetric creation in the middle and bottom layers. Tectonic extension creates volume which can accomodate magmatic intrusions. Spreading models assume this volume is distributed throughout the whole region, perhaps in vertical dykes, whereas rifting models assume the upper crust is thinned and the volume created lies under this upper crust. Bounds on the heat flow from such magmatic intrusions are calculated. Heat flow calculations are performed and some examples are provided which match the present total heat output from the TVZ of about 4200 MW, but these either have extension rates greater than the low values of about 8 ± 4 mm/a being reported from GPS measurements, or else consider extension rates in the TVZ to have varied over time.

  12. Volcanic eruptions observed with infrasound

    Science.gov (United States)

    Johnson, Jeffrey B.; Aster, Richard C.; Kyle, Philip R.

    2004-07-01

    Infrasonic airwaves produced by active volcanoes provide valuable insight into the eruption dynamics. Because the infrasonic pressure field may be directly associated with the flux rate of gas released at a volcanic vent, infrasound also enhances the efficacy of volcanic hazard monitoring and continuous studies of conduit processes. Here we present new results from Erebus, Fuego, and Villarrica volcanoes highlighting uses of infrasound for constraining quantitative eruption parameters, such as eruption duration, source mechanism, and explosive gas flux.

  13. Waist Circumferences of Chilean Students: Comparison of the CDC-2012 Standard and Proposed Percentile Curves

    Directory of Open Access Journals (Sweden)

    Rossana Gómez-Campos

    2015-07-01

    Full Text Available The measurement of waist circumference (WC is considered to be an important means to control overweight and obesity in children and adolescents. The objectives of the study were to (a compare the WC measurements of Chilean students with the international CDC-2012 standard and other international standards, and (b propose a specific measurement value for the WC of Chilean students based on age and sex. A total of 3892 students (6 to 18 years old were assessed. Weight, height, body mass index (BMI, and WC were measured. WC was compared with the CDC-2012 international standard. Percentiles were constructed based on the LMS method. Chilean males had a greater WC during infancy. Subsequently, in late adolescence, males showed values lower than those of the international standards. Chilean females demonstrated values similar to the standards until the age of 12. Subsequently, females showed lower values. The 85th and 95th percentiles were adopted as cutoff points for evaluating overweight and obesity based on age and sex. The WC of Chilean students differs from the CDC-2012 curves. The regional norms proposed are a means to identify children and adolescents with a high risk of suffering from overweight and obesity disorders.

  14. Paleomagnetism of Permian and Triassic rock, central Chilean Andes

    Science.gov (United States)

    Forsythe, Randall D.; Kent, Dennis V.; Mpodozis, Constantino; Davidson, John

    The first paleomagnetic data from Permian and Triassic formations west of the Andean divide are presented. Four formations of Permian or Triassic age in the central Chilean Andes have been investigated: two are located in the coastal ranges, and two are in the main cordillera. Of the formations in the main cordillera (Pastos Blancos and Matahuaico formations), only the Pastos Blancos Formation has yielded characteristic directions. While a fold test is absent, magnetizations are most likely secondary and yield pre-tilt corrected concordant inclinations, but yield declinations discordant 30° clockwise in comparison to the South American apparent polar wander path. Both formations from the coastal ranges (Cifuncho and Pichidangui formations) yielded stable directions. Postfolding magnetizations in the Cifuncho Formation also show declinations discordant 30° clockwise and concordant inclinations. The Pichidangui Formation has two stable components: one of postfolding age is concordant to apparent polar wander path data, and one of probable prefolding (Late Triassic) age is concordant in declination, but discordant in inclination. Further work is needed to better define the prefolding magnetizations in the Pichidangui Formation, but at present these preliminary results are the first paleomagnetic signs of displaced terranes along the Pacific margin of Chile. If correct, the results suggest that the Pichidangui Formation was some 15° of latitude farther south during the Late Triassic and had likely moved northward to its present latitudinal position with respect to cratonic South America by Middle to Late Jurassic.

  15. Peer victimization: Intimidation and victmization in Chilean students

    Directory of Open Access Journals (Sweden)

    Verónica López

    2009-12-01

    Full Text Available This paper presents the results of a study about peer intimidation and victimization with 1167 school students from 6th, 7th, and 8th grade from the Valparaiso Region of Valparaíso, Chile. The instrument used was the Insebull Battery (Avilés & Elices, 2007. Results show that approximately 9% of students have been victim of peer victimization many times or almost every day during the school year. Psychological victimization was more frequent thanphysical aggression, particularly through virtual communication such as cell-phone messages and e-mails. Participants tend to be groups of male students. Although male students participate more in physical aggression, they also receive more physical and psychological aggression. The most frequent places were inside the classroom and the school yard, when the teacher is not present. Most students inform not knowing, or vaguely knowing, thereasons underlying these aggressions, and do not do anything to deal with them. These results coincide with international studies and allow a better understanding of the characteristics of peer victimization in specific educational contexts within the Chilean school system.

  16. Banking reform and the financing of firm investment : An empirical analysis of the Chilean experience, 1983-92

    NARCIS (Netherlands)

    Hermes, N; Lensink, R

    1998-01-01

    This article investigates whether the Chilean banking reforms of the 1980s have contributed to reducing market imperfections in Chilean financial markets in the late 1980 and early 1990s. To analyse this issue, patterns of investment and its finance for different types of firms are studied, based on

  17. Geochemical Interpretation of Collision Volcanism

    Science.gov (United States)

    Pearce, Julian

    2014-05-01

    Collision volcanism can be defined as volcanism that takes place during an orogeny from the moment that continental subduction starts to the end of orogenic collapse. Its importance in the Geological Record is greatly underestimated as collision volcanics are easily misinterpreted as being of volcanic arc, extensional or mantle plume origin. There are many types of collision volcanic province: continent-island arc collision (e.g. Banda arc); continent-active margin collision (e.g. Tibet, Turkey-Iran); continent-rear-arc collision (e.g. Bolivia); continent-continent collision (e.g. Tuscany); and island arc-island arc collision (e.g. Taiwan). Superimposed on this variability is the fact that every orogeny is different in detail. Nonetheless, there is a general theme of cyclicity on different time scales. This starts with syn-collision volcanism resulting from the subduction of an ocean-continent transition and continental lithosphere, and continues through post-collision volcanism. The latter can be subdivided into orogenic volcanism, which is related to thickened crust, and post-orogenic, which is related to orogenic collapse. Typically, but not always, collision volcanism is preceded by normal arc volcanism and followed by normal intraplate volcanism. Identification and interpretation of collision volcanism in the Geologic Record is greatly facilitated if a dated stratigraphic sequence is present so that the petrogenic evolution can be traced. In any case, the basis of fingerprinting collision terranes is to use geochemical proxies for mantle and subduction fluxes, slab temperatures, and depths and degrees of melting. For example, syn-collision volcanism is characterized by a high subduction flux relative to mantle flux because of the high input flux of fusible sediment and crust coupled with limited mantle flow, and because of high slab temperatures resulting from the decrease in subduction rate. The resulting geochemical patterns are similar regardless of

  18. TRADE POLICY AND MAJOR TRENDS IN CHILEAN EXPORTS UNDER DEMOCRACY, 1990-2012

    Directory of Open Access Journals (Sweden)

    Manuel Llorca-Jaña

    2015-06-01

    Full Text Available This paper deals with trade policy and the principal trends in Chilean exports after the return to democracy in 1990. During this period, both exports and imports expanded significantly in Chile. As far as exports are concerned, this boom is mainly due to an effective trade policy of additive regionalism, booming copper prices, export diversification and the economic dynamism of China, the principal beneficiary of Chilean exports. On the negative side, the country is still too dependant on copper and a few other primary products. In addition, nowadays, in relative terms Chile is exporting more copper minerals and less refined copper than it used to do in the 1990s, while Chilean exports remained highly concentrated in a few companies only, many of which belong to foreign nationals.

  19. HIV prevention and low-income Chilean women: machismo, marianismo and HIV misconceptions.

    Science.gov (United States)

    Cianelli, Rosina; Ferrer, Lilian; McElmurry, Beverly J

    2008-04-01

    Socio-cultural factors and HIV-related misinformation contribute to the increasing number of Chilean women living with HIV. In spite of this, and to date, few culturally specific prevention activities have been developed for this population. The goal of the present study was to elicit the perspectives of low-income Chilean women regarding HIV and relevant socio-cultural factors, as a forerunner to the development of a culturally appropriate intervention. As part of a mixed-methods study, fifty low-income Chilean women participated in a survey and twenty were selected to participate in prevention, in-depth interviews. Results show evidence of widespread misinformation and misconceptions related to HIV/AIDS. Machismo and marianismo offer major barriers to prevention programme development. Future HIV prevention should stress partner communication, empowerment and improving the education of women vulnerable to HIV.

  20. Reporting quality of papers published in Chilean dental journals. Evaluation period: 2002-2012.

    Directory of Open Access Journals (Sweden)

    Sergio E Uribe

    2015-08-01

    Full Text Available Aim: To assess the reporting quality of papers published between 2002-2012 in Chilean dental journals. Methods: Bibliometric analysis of research papers published in indexed Chilean dental journals between 2002-2012. Three calibrated examinators (interoperator- Kappa=.83 assessed 205 papers: 150 case-reports, 37 observational studies and 18 clinical trials. Reporting quality was evaluated using CARE for case reports, STROBE for observational studies and CONSORT for clinical trials. Descriptive statistics were conducted. Results: Case-reports reported 35% of the required methodological items; epidemiological research reported 16% of required items for Materials and Methods and 10% for Results. Clinical research reported 29% of required Materials and Methods items and 20% of Results items. Conclusion: Case-report, epidemiological and clinician research papers in Chilean dental journals published during the 2002-2012 period are lacking explicit key methodological items, preventing a proper research replication or clinical application of the results.

  1. Privatizing Water in the Chilean Andes: The Case of Las Vegas de Chiu-Chiu

    Directory of Open Access Journals (Sweden)

    Manuel Prieto

    2015-08-01

    Full Text Available The Chilean water model has been described as a textbook example of a free-market water system. This article contributes to the critiques of this model by showing the effect of its implementation in the Atacameño community of Chiu-Chiu, located in the Atacama Desert in the south-central Andes. In this community, the privatization of water rights ignored local water management practices that had produced a high-altitude wetland (known as a vega. This led to the inhabitants’ dispossession of crucial water rights and to wetland degradation. This process belies statements that the Chilean model relies on an unregulated market and instead highlights the state’s role in marginalizing local irrigation practices by reducing the water consumption of the indigenous population while keeping the copper mining industry (the main source of Chilean income and related growing urban populations supplied with water.

  2. On water in volcanic clouds

    Science.gov (United States)

    Durant, Adam J.

    2007-12-01

    Volcanic clouds and tephra fallout present a hazard to aviation, human and animal health (direct inhalation or ingestion, contamination of water supplies), and infrastructure (building collapse, burial of roads and railways, agriculture, abrasive and chemical effects on machinery). Understanding sedimentation processes is a fundamental component in the prediction of volcanic cloud lifetime and fallout at the ground, essential in the mitigation of these hazards. The majority of classical volcanic ash transport and dispersion models (VATDM) are based solely on fluid dynamics. The non-agreement between VATDM and observed regional-scale tephra deposit characteristics is especially obvious at large distances from the source volcano. In meteorology, the processes of hydrometeor nucleation, growth and collection have been long-established as playing a central role in sedimentation and precipitation. Taking this as motivation, the hypothesis that hydrometeor formation drives sedimentation from volcanic clouds was tested. The research objectives of this dissertation are: (1) To determine the effectiveness of tephra particles in the catalysis of the liquid water to ice phase transformation, with application to ice hydrometeor formation in volcanic clouds. (2) To determine the sedimentological characteristics of distal (100s km) tephra fallout from recent volcanic clouds. (3) To assess particle fallout rates from recent volcanic clouds in the context of observed deposit characteristics. (4) To assess the implications of hydrometeor formation on the enhancement of volcanic sedimentation and the potential for cloud destabilization from volcanic hydrometeor sublimation. Dissertation Overview. The following chapters present the analysis, results and conclusions of heterogeneous ice nucleation experiments and sedimentological characterization of several recent tephra deposits. The dissertation is organized in three chapters, each prepared in journal article format. In Chapter 1

  3. Climatic impact of volcanic eruptions

    Science.gov (United States)

    Rampino, Michael R.

    1991-01-01

    Studies have attempted to 'isolate' the volcanic signal in noisy temperature data. This assumes that it is possible to isolate a distinct volcanic signal in a record that may have a combination of forcings (ENSO, solar variability, random fluctuations, volcanism) that all interact. The key to discovering the greatest effects of volcanoes on short-term climate may be to concentrate on temperatures in regions where the effects of aerosol clouds may be amplified by perturbed atmospheric circulation patterns. This is especially true in subpolar and midlatitude areas affected by changes in the position of the polar front. Such climatic perturbation can be detected in proxy evidence such as decrease in tree-ring widths and frost rings, changes in the treeline, weather anomalies, severity of sea-ice in polar and subpolar regions, and poor grain yields and crop failures. In low latitudes, sudden temperature drops were correlated with the passage overhead of the volcanic dust cloud (Stothers, 1984). For some eruptions, such as Tambora, 1815, these kinds of proxy and anectdotal information were summarized in great detail in a number of papers and books (e.g., Post, 1978; Stothers, 1984; Stommel and Stommel, 1986; C. R. Harrington, in press). These studies lead to the general conclusion that regional effects on climate, sometimes quite severe, may be the major impact of large historical volcanic aerosol clouds.

  4. Atmospheric chemistry in volcanic plumes.

    Science.gov (United States)

    von Glasow, Roland

    2010-04-13

    Recent field observations have shown that the atmospheric plumes of quiescently degassing volcanoes are chemically very active, pointing to the role of chemical cycles involving halogen species and heterogeneous reactions on aerosol particles that have previously been unexplored for this type of volcanic plumes. Key features of these measurements can be reproduced by numerical models such as the one employed in this study. The model shows sustained high levels of reactive bromine in the plume, leading to extensive ozone destruction, that, depending on plume dispersal, can be maintained for several days. The very high concentrations of sulfur dioxide in the volcanic plume reduces the lifetime of the OH radical drastically, so that it is virtually absent in the volcanic plume. This would imply an increased lifetime of methane in volcanic plumes, unless reactive chlorine chemistry in the plume is strong enough to offset the lack of OH chemistry. A further effect of bromine chemistry in addition to ozone destruction shown by the model studies presented here, is the oxidation of mercury. This relates to mercury that has been coemitted with bromine from the volcano but also to background atmospheric mercury. The rapid oxidation of mercury implies a drastically reduced atmospheric lifetime of mercury so that the contribution of volcanic mercury to the atmospheric background might be less than previously thought. However, the implications, especially health and environmental effects due to deposition, might be substantial and warrant further studies, especially field measurements to test this hypothesis.

  5. Geopulsation, Volcanism and Astronomical Periods

    Institute of Scientific and Technical Information of China (English)

    Yang Xuexiang; Chen Dianyou; Yang Xiaoying; Yang Shuchen

    2000-01-01

    Volcanism is mainly controlled by the intermittent release of energy in the earth. As far as the differential rotation of the earth's inner core is concerned, the Galactic Year may change the gravitational constant G, the solar radiative quantity and the moving speed of the solar system and affect the exchange of angular momentum between core and mantle as well as the energy exchange between crust and mantle. As a result, this leads to eruptions of superplumes and magma, and controls the energy flow from core - mantle boundary (CMB) to crust. When the earth' s speed decreases, it will release a huge amount of energy. They are the reason of the correspondence of the volcanic cycles one by one with the astronomical periods one by one. According to the astronomical periods, volcanic eruptions may possibly be predicted in the future.

  6. Geochemical study for volcanic surveillance

    Energy Technology Data Exchange (ETDEWEB)

    Panichi, C.; La Ruffa, G. [Consiglio Nazionale delle Ricerche, International Institute for Geothermal Research Ghezzano, PI (Italy)

    2000-07-01

    For years, geologists have been striving to reconstruct volcanic eruptions from the analysis of pyroclastic deposits and lava flows on the surface of the earth and in the oceans. This effort has produced valuable information on volcanic petrology and magma generation, separation, mixing, crystallisation, and interaction with water in phreatomagmatic and submarine eruptions. The volcanological process are tied to the dynamics of the earth's crust and lithosphere. The mantle, subducted oceanic crust, and continental crust contain different rock types and are sources of different magmas. Magmas consist primarily of completely or partially molten silicates containing volatile materials either dissolved in the melt or as bubbles of gas. The silicate and volatile portions affect the physical properties of magma and, therefore, the nature of a volcanic eruption.

  7. Science of Tsunami Forecasting: 2010 Chilean Tsunami Challenge

    Science.gov (United States)

    Titov, Vasily; Bernard, Eddie; Tang, Rachel; Wei, Yong; Uslu, Burak; Eble, Marie

    2010-05-01

    Tsunami forecasting with real-time models and real-time data has always been one of the main goals of tsunami research. The February 27th, 2010 Chile tsunami provided the challenge and the opportunity to test the modern state of the science in tsunami forecasting. By contrast with the previous basin-wide tsunami generated by the third largest 2004 Sumatra earthquake, the fifth largest Chilean earthquake occurred at the time and in the area where a variety of real-time measurements and model forecast models have been available to assess the generated tsunami in real-time. The Chile tsunami was generated by a Mw 8.8 earthquake (35.846S, 72.719W ), at 06:34 UTC, 115 km (60 miles) NNE of Concepcion, Chile (according to the USGS). It has been recorded at coastal sea level gages around the Pacific Ocean, staring from the near-field record that caught the wave half an hour after generation at Valparaiso, to the coastal recordings of the wave arrived at Japan and Russian Far East almost a day later. In approximately 3 hours after the earthquake, the tsunami was first recorded at DART buoy 32412, providing real-time deep ocean signature of the propagating tsunami. All that measurements provided ample data for the real-time forecast analysis and for the model performance and forecast skills assessment throughout the Pacific basin. We present results of the performance of the NOAA forecast. The forecast method uses MOST model with the data assimilated from the earthquake and deep-ocean tsunami DART measurement. The comparison with tide gages and coastal impacts provide opportunity to assess the accuracy and efficiency of the forecast. The successes, lessons learned and future challengers for the tsunami forecast science are discussed.

  8. Organic carbon in glacial fjords of Chilean Patagonia

    Science.gov (United States)

    Pantoja, Silvio; Gutiérrez, Marcelo; Tapia, Fabián; Abarzúa, Leslie; Daneri, Giovanni; Reid, Brian; Díez, Beatriz

    2016-04-01

    The Southern Ice Field in Chilean Patagonia is the largest (13,000 km2) temperate ice mass in the Southern hemisphere, yearly transporting ca. 40 km3 of freshwater to fjords. This volume of fresh and cold water likely affects adjacent marine ecosystems by changing circulation, productivity, food web dynamics, and the abundance and distribution of planktonic and benthic organisms. We hypothesize that freshwater-driven availability of inorganic nutrient and transport of organic and inorganic suspended matter, as well as microbes, become a controlling factor for productivity in the fjord associated with the Baker river and Jorge Montt glacier. Both appear to be sources of silicic acid, but not of nitrate and particulate organic carbon, especially during summer, when surface PAR and glacier thawing are maximal. In contrast to Baker River, the Jorge Montt glacier is also a source of dissolved organic carbon towards a proglacial fjord and the Baker Channel, indicating that a thorough chemical description of sources (tidewater glacier and glacial river) is needed. Nitrate in fiord waters reaches ca. 15 μM at 25 m depth with no evidence of mixing up during summer. Stable isotope composition of particulate organic nitrogen reaches values as low as 3 per mil in low-salinity waters near both glacier and river. Nitrogen fixation could be depleting δ15N in organic matter, as suggested by the detection at surface waters of nif H genes belonging to diazotrophs near the Montt glacier. As diazotrophs have also been detected in other cold marine waters (e.g. Baltic Sea, Arctic Ocean) as well as glaciers and polar terrestrial waters, there is certainly a potential for both marine and freshwater microbes to contribute and have a significant impact on the Patagonian N and C budgets. Assessing the impact of freshwater on C and N fluxes and the microbial community structure in Patagonian waters will allow understanding future scenarios of rapid glacier melting. This research was funded

  9. L'imaginaire du volcan

    OpenAIRE

    Bertrand, Dominique; Bosquet, Marie-Françoise; Bozzetto, Roger; Chamart, Gabrielle; Chelebourg, Christian; Chenet-Faugeras, Françoise; Collot, Michel; Cornille, Jean-Louis; Gaillard, Aurélia; Lavocat, Françoise; Frank LESTRINGANT; Racault, Jean-Michel; SHINODA, Chiwaki; Sylvos, Françoise; Tardieu, Jean-Pierre

    2016-01-01

    Quelle force naturelle pouvait, mieux que le volcan, devenir la métaphore vive de l'enthousiasme poétique ? Auteur du paysage qu'il remodèle après l'avoir détruit, sculpteur de laves autant qu'objet pittoresque, le volcan est dans la littérature un actant essentiel, un relais de l'auteur, comme le montre ce voyage dans la mémoire des représentations volcaniques.

  10. Sismos y volcanes en Colombia

    OpenAIRE

    Duque Escobar, Gonzalo

    2010-01-01

    Notas sobre las zonas de amenaza sísmica y principales fuentes sísmicas de Colombia, y los segmentos volcánicos de los Andes colombianos con los principales volcanes activos, de conformidad con los estudios del Ingeominas. Anexos a títulos con sus correspondientes enlaces, para ofrecer artículos relacionados con sismos y volcanes, en los que se consideran aspectos de interés para la gestión del riesgo sísmico y volcánico en Colombia

  11. Recurrence models of volcanic events: Applications to volcanic risk assessment

    Energy Technology Data Exchange (ETDEWEB)

    Crowe, B.M. [Los Alamos National Lab., Las Vegas, NV (United States); Picard, R.; Valentine, G. [Los Alamos National Lab., NM (United States); Perry, F.V. [New Mexico Univ., Albuquerque, NM (United States)

    1992-03-01

    An assessment of the risk of future volcanism has been conducted for isolation of high-level radioactive waste at the potential Yucca Mountain site in southern Nevada. Risk used in this context refers to a combined assessment of the probability and consequences of future volcanic activity. Past studies established bounds on the probability of magmatic disruption of a repository. These bounds were revised as additional data were gathered from site characterization studies. The probability of direct intersection of a potential repository located in an eight km{sup 2} area of Yucca Mountain by ascending basalt magma was bounded by the range of 10{sup {minus}8} to 10{sup {minus}10} yr{sup {minus}1 2}. The consequences of magmatic disruption of a repository were estimated in previous studies to be limited. The exact releases from such an event are dependent on the strike of an intruding basalt dike relative to the repository geometry, the timing of the basaltic event relative to the age of the radioactive waste and the mechanisms of release and dispersal of the waste radionuclides in the accessible environment. The combined low probability of repository disruption and the limited releases associated with this event established the basis for the judgement that the risk of future volcanism was relatively low. It was reasoned that that risk of future volcanism was not likely to result in disqualification of the potential Yucca Mountain site.

  12. Recurrence models of volcanic events: Applications to volcanic risk assessment

    International Nuclear Information System (INIS)

    An assessment of the risk of future volcanism has been conducted for isolation of high-level radioactive waste at the potential Yucca Mountain site in southern Nevada. Risk used in this context refers to a combined assessment of the probability and consequences of future volcanic activity. Past studies established bounds on the probability of magmatic disruption of a repository. These bounds were revised as additional data were gathered from site characterization studies. The probability of direct intersection of a potential repository located in an eight km2 area of Yucca Mountain by ascending basalt magma was bounded by the range of 10-8 to 10-10 yr-12. The consequences of magmatic disruption of a repository were estimated in previous studies to be limited. The exact releases from such an event are dependent on the strike of an intruding basalt dike relative to the repository geometry, the timing of the basaltic event relative to the age of the radioactive waste and the mechanisms of release and dispersal of the waste radionuclides in the accessible environment. The combined low probability of repository disruption and the limited releases associated with this event established the basis for the judgement that the risk of future volcanism was relatively low. It was reasoned that that risk of future volcanism was not likely to result in disqualification of the potential Yucca Mountain site

  13. Using Volcanic Ash to Remove Dissolved Uranium and Lead

    Science.gov (United States)

    McKay, David S.; Cuero, Raul G.

    2009-01-01

    Experiments have shown that significant fractions of uranium, lead, and possibly other toxic and/or radioactive substances can be removed from an aqueous solution by simply exposing the solution, at ambient temperature, to a treatment medium that includes weathered volcanic ash from Pu'u Nene, which is a cinder cone on the Island of Hawaii. Heretofore, this specific volcanic ash has been used for an entirely different purpose: simulating the spectral properties of Martian soil. The treatment medium can consist of the volcanic ash alone or in combination with chitosan, which is a natural polymer that can be produced from seafood waste or easily extracted from fungi, some bacteria, and some algae. The medium is harmless to plants and animals and, because of the abundance and natural origin of its ingredient( s), is inexpensive. The medium can be used in a variety of ways and settings: it can be incorporated into water-filtration systems; placed in contact or mixed with water-containing solids (e.g., soils and sludges); immersed in bodies of water (e.g., reservoirs, lakes, rivers, or wells); or placed in and around nuclear power plants, mines, and farm fields.

  14. La infografía de 'El Mercurio' de Chile. Chilean El Mercurio's infographics Chilean El Mercurio's infographics

    Directory of Open Access Journals (Sweden)

    Raymond Colle

    Full Text Available Resumen: El diario chileno El Mercurio incluye algunas veces en sus artículos la mención «ver infografía» para invitar a los lectores a completar la lectura con la observación de un cuadro anexo. Este cuadro, sin embargo, no siempre incluye un elemento icónico: como lo demostramos aquí, este diario utiliza una definición extremadamente amplia del concepto de infografía. Además de presentar aquí las características de todos los infográficos publicados en enero y febrero de 2009, mostramos también que los casos en que aparece la mención «ver infografía» no son predecibles a partir de estos cuadros y que éstos no se distinguen, por sus características, del resto de los publicados.Abstract:The chilean newspaper El Mercurio sometimes include in their articles the words «see infographics» inviting readers to complete the reading with the observation of an annexed table. This table, however, does not always include an iconic: as we demonstrated here, this newspaper uses an extremely broad definition of the concept of infographics. Apart from presenting here the characteristics of all infographics published in January and February 2009, we also show that cases in which the words «see infographics» are not predictable from these graphics and they are not distinguished by their characteristics from the rest of them.

  15. A quantitative model for volcanic hazard assessment

    OpenAIRE

    Marzocchi, W.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Sandri, L.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia; Furlan, C.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia

    2006-01-01

    Volcanic hazard assessment is a basic ingredient for risk-based decision-making in land-use planning and emergency management. Volcanic hazard is defined as the probability of any particular area being affected by a destructive volcanic event within a given period of time (Fournier d’Albe 1979). The probabilistic nature of such an important issue derives from the fact that volcanic activity is a complex process, characterized by several and usually unknown degrees o...

  16. Volcanic ash - Terrestrial versus extraterrestrial

    Science.gov (United States)

    Okeefe, J. A.

    1976-01-01

    A principal difference between terrestrial and extraterrestrial lavas may consist in the greater ability of terrestrial lavas to form thin films (like those of soap bubbles) and hence foams. It would follow that, in place of the pumice and spiny shards found in terrestrial volcanic ash, an extraterrestrial ash should contain minute spherules. This hypothesis may help to explain lunar microspherules.

  17. Lung problems and volcanic smog

    Science.gov (United States)

    ... www.ncbi.nlm.nih.gov/pubmed/17650330 . Volcanic Air Pollution -- A Hazard in Hawai'i. U.S. Geological Survey. Last updated October 2004. U.S. Geological Survey Fact Sheet 169-197. Accessed April 22, 2012. Available at: ...

  18. Infrasound research of volcanic eruptions

    Science.gov (United States)

    Marchetti, Emanuele; Ripepe, Maurizio

    2016-04-01

    Volcanic eruptions are efficient sources of infrasound produced by the rapid perturbation of the atmosphere by the explosive source. Being able to propagate up to large distances from the source, infrasonic waves from major (VEI 4 or larger) volcanic eruptions have been recorded for many decades with analogue micro-barometers at large regional distances. In late 1980s, near-field observations became progressively more common and started to have direct impact on the understanding and modeling of explosive source dynamics, to eventually play a primary role in volcano research. Nowadays, infrasound observation from a large variety of volcanic eruptions, spanning from VEI 0 to VEI 5 events, has shown a dramatic variability in terms of signature, excess pressure and frequency content of radiated infrasound and has been used to infer complex eruptive source mechanisms for the different kinds of events. Improved processing capability and sensors has allowed unprecedented precise locations of the explosive source and is progressively increasing the possibility to monitor volcanoes from distant records. Very broadband infrasound observations is also showing the relation between volcanic eruptions and the atmosphere, with the eruptive mass injection in the atmosphere triggering acoustic-gravity waves which eventually might control the ash dispersal and fallout.

  19. Disruptive event analysis: volcanism and igneous intrusion

    International Nuclear Information System (INIS)

    Three basic topics are addressed for the disruptive event analysis: first, the range of disruptive consequences of a radioactive waste repository by volcanic activity; second, the possible reduction of the risk of disruption by volcanic activity through selective siting of a repository; and third, the quantification of the probability of repository disruption by volcanic activity

  20. Experimental generation of volcanic lightning

    Science.gov (United States)

    Cimarelli, Corrado; Alatorre-Ibargüengoitia, Miguel; Kueppers, Ulrich; Scheu, Bettina; Dingwell, Donald B.

    2014-05-01

    Ash-rich volcanic plumes that are responsible for injecting large quantities of aerosols into the atmosphere are often associated with intense electrical activity. Direct measurement of the electric potential at the crater, where the electric activity in the volcanic plume is first observed, is severely impeded, limiting progress in its investigation. We have achieved volcanic lightning in the laboratory during rapid decompression experiments of gas-particle mixtures under controlled conditions. Upon decompression (from ~100 bar argon pressure to atmospheric pressure), loose particles are vertically accelerated and ejected through a nozzle of 2.8 cm diameter into a large tank filled with air at atmospheric conditions. Because of their impulsive character, our experiments most closely represent the conditions encountered in the gas-thrust region of the plume, when ash is first ejected from the crater. We used sieved natural ash with different grain sizes from Popocatépetl (Mexico), Eyjafjallajökull (Iceland), and Soufrière Hills (Montserrat) volcanoes, as well as micrometric glass beads to constrain the influence of material properties on lightning. We monitored the dynamics of the particle-laden jets with a high-speed camera and the pressure and electric potential at the nozzle using a pressure transducer and two copper ring antennas connected to a high-impedance data acquisition system, respectively. We find that lightning is controlled by the dynamics of the particle-laden jet and by the abundance of fine particles. Two main conditions are required to generate lightning: 1) self-electrification of the particles and 2) clustering of the particles driven by the jet fluid dynamics. The relative movement of clusters of charged particles within the plume generates the gradient in electrical potential, which is necessary for lightning. In this manner it is the gas-particle dynamics together with the evolving particle-density distribution within different regions of

  1. Home and Instruction Effects on Emergent Literacy in a Sample of Chilean Kindergarten Children

    Science.gov (United States)

    Strasser, Katherine; Lissi, Maria Rosa

    2009-01-01

    The study examines the home literacy experiences, emergent literacy skills, and instructional experiences of a sample of Chilean kindergarten children (n = 126) and kindergarten families (n = 188) nested in 12 kindergarten classrooms from different socioeconomic status groups and types of schools. Descriptive information is given showing the level…

  2. The Dad in the Che Guevara T-Shirt: Narratives of Chilean English Teachers

    Science.gov (United States)

    Menard-Warwick, Julia

    2008-01-01

    Building on previous critical research regarding student resistance to English Language Teaching (ELT), this paper illustrates Chilean high-school English teachers' use of narrative to make sense of ideological challenges from students. While the government of Chile is promoting English in connection with the nation's export-oriented economic…

  3. Bruises in Chilean cattle: their characterization, occurrence and relation with pre-slaughter conditions

    NARCIS (Netherlands)

    Strappini, A.C.

    2012-01-01

    Bruises on cattle carcass affect the quality of the meat and are indicators of poor welfare conditions. According to the literature the occurrence of bruises is related to pre- slaughter conditions, however their contribution is not clear for Chilean cattle. The aim of this thesis was to provide a b

  4. Estimating enteric methane emissions from Chilean beef fattening systems using a mechanistic model

    NARCIS (Netherlands)

    Arias, R.A.; Catrileo, A.; Larraín, R.; Vera, R.; Velásquez, A.; Toneatti, M.; France, J.; Dijkstra, J.; Kebreab, E.

    2015-01-01

    A mechanistic model (COWPOLL) was used to estimate enteric methane (CH4) emissions from beef production systems in Chile. The results expressed as a proportion of gross energy intake (GEI) were compared with enteric fermentation data reported in the last Chilean greenhouse gases inventory, which uti

  5. Chilean Adolescents' and Parents' Views on Autonomy Development

    Science.gov (United States)

    Martínez, M. Loreto; Pérez, J. Carola; Cumsille, Patricio

    2014-01-01

    This study aims to understand Chilean parents' and adolescents' conceptions of autonomy and whether they hold different expectations for autonomous behaviors by generation and socioeconomic level. A qualitative approach to data collection was used through separate focus groups of parents and adolescents from different socioeconomic…

  6. New English Cultures and Learner Autonomy for Intrinsic Motivation and Democratic Empowerment in the Chilean Context

    Science.gov (United States)

    Glas, Katharina; Cardenas-Claros, Monica S.

    2013-01-01

    Chilean youth are currently demanding access to better-quality education for all: greater democracy and curricula that respect the country's indigenous cultural roots form part of their petitions. This article puts forward a twofold pedagogical proposal for English Language Teaching intended to foster intrinsic motivation and democratic…

  7. Morphology, anatomy and histology of Doto uva Marcus, 1955 (Opisthobranchia: Nudibranchia) from the Chilean coast

    NARCIS (Netherlands)

    Fischer, M.A.; Velde, van der G.; Roubos, E.W.

    2006-01-01

    Doto uva Marcus, 1955 is a nudibranch species recorded from the Brazilian and Chilean coast. In spite of its wide distribution, D. uva has been described only superficially, mainly as to the pattern of its coloration, external morphology, radular teeth and reproductive system. Here we substantially

  8. [Recommendations for Chilean travelers to the FIFA World Cup 2014 in Brazil].

    Science.gov (United States)

    Perret, Cecilia; Weitzel, Thomas

    2014-04-01

    This article provides a checklist of precautions and vaccines for Chilean travelers attending the FIFA World Cup 2014 in Brazil. It aims to help physicians to prepare visitors of this mass gathering and summarizes useful hints to avoid infectious diseases considering the circumstances and availabilities in Chile.

  9. Eating Disorders among a Community-Based Sample of Chilean Female Adolescents

    Science.gov (United States)

    Granillo, M. Teresa; Grogan-Kaylor, Andrew; Delva, Jorge; Castillo, Marcela

    2011-01-01

    The purpose of this study was to explore the prevalence and correlates of eating disorders among a community-based sample of female Chilean adolescents. Data were collected through structured interviews with 420 female adolescents residing in Santiago, Chile. Approximately 4% of the sample reported ever being diagnosed with an eating disorder.…

  10. Educational Effectiveness in Chilean Secondary Education: Comparing Different "Value Added" Approaches to Evaluate Schools

    Science.gov (United States)

    Muñoz-Chereau, B.; Thomas, S. M.

    2016-01-01

    This article reports an original investigation into school performance measures and the multilevel nature of pupil achievement data in the Chilean school system using a sample of 177,461 students, nested within 7146 classrooms, 2283 secondary schools and 313 municipalities. The data-set comprised Year 10 students' 2006 SIMCE test's results in two…

  11. Bringing the Schools Back in: The Stratification of Educational Achievement in the Chilean Voucher System

    Science.gov (United States)

    Mizala, Alejandra; Torche, Florencia

    2012-01-01

    This paper analyzes the socioeconomic stratification of achievement in the Chilean voucher system using a census of 4th and 8th graders, a multilevel methodology, and accounting for unobserved selectivity into school sector. Findings indicate that the association between the school's aggregate family socioeconomic status (SES) and test scores is…

  12. The Chilean miracle : patrimonialism in a modern free-market democracy

    NARCIS (Netherlands)

    Peppelenbos, L.P.C.

    2005-01-01

    International policy institutions claim that Chile's remarkable economic performance testifies to the merits of a neo-liberal development model. This book argues, however, that 'the Chilean miracle' did not result from the adoption ofneoliberalismitself, but from the persis

  13. Testing hypotheses for the use of Icelandic volcanic ashes as low cost, natural fertilizers

    Science.gov (United States)

    Seward, W.; Edwards, B.

    2012-04-01

    Andisols are soils derived from tephra/volcanic bedrock and are generally considered to be fertile for plant growth (cf. University of Hawaii at Manoa, CTAHR). However, few studies have been published examining the immediate effects of the addition of volcanic ash to soils immediately after an eruption. Our research is motivated by unpublished accounts from Icelandic farmers that the growing season following the 2010 Eyjafjallajökull eruption ended with unusually high yields in areas that were covered by ash from the eruption early in the spring. To test the hypothesis that addition of volcanic ash to soil would have no immediate effect on plant growth, we conducted a ~6 week growth experiment in at controlled environment at the Dickinson College Farm. The experiment used relatively fast growing grain seeds as a test crop, controlled watering, known quantities of peat as an organic base, and the following general experimental design: peat was mixed in known but systematically differing proportions with 1) commercial quartz sand, 2) basaltic ash from the 2004 Grimsvötn eruption, and 3) trachyandesite ash from the 2010 Eyjafjallajökull eruption. For all experiments, the seeds growing in the simulated soil created with the two different composition volcanic ash had higher germination rates, higher growth rates, and produced plants that were healthier in appearance than the soil made from peat mixed with quartz sand. Some differences were also noted between the germination and grow rates between the basaltic and trachyandesitic ash experiments as well. Working hypotheses to explain these results include (1) shard shapes and vesicles from volcanic ash provide better water retention than quartz, allowing water to be stored longer and increasing average soil moisture, and (2) chemical nutrients from the ash facilitate germination and growth of plants. Documenting the potential benefits of fresh volcanic ash as a fertilizer is important as use of fresh ash fertlizer

  14. Geochemical evidence for waning magmatism and polycyclic volcanism at Crater Flat, Nevada

    Science.gov (United States)

    Perry, F. V.; Crowe, B. M.

    Petrologic and geochemical studies of basaltic rocks in the Yucca Mountain region are currently focused on understanding the evolution of volcanism in the Crater Flat volcanic field and the mechanisms of polycyclic volcanism at the Lathrop Wells volcanic center, the youngest center in the Crater Flat volcanic field. Geochemical and petrologic data indicate that the magma chambers which supplied the volcanic centers in Crater Flat became situated at greater crustal depths as the field evolved. Deep magma chambers may be related to a waning magma flux that was unable to sustain upper crystal magma conduits and chambers. Geochemical data from the Lathrop Wells volcanic center indicate that eruptive units identified from field and geomorphic relationships are geochemically distinct. The geochemical variations cannot be explained by fractional crystallization of a single magma batch, indicating that several magma batches were involved in the formation of the Lathrop Wells center. Considering the low magma flux in the Yucca Mountain region in the Quaternary, the probability of several magma batches erupting essentially simultaneously at Lathrop Wells in considered remote. It is more likely that the Lathrop Wells center was formed by a series of eruptions that took place over many thousands of years. The geochemical data from Lathrop Wells is consistent with the concept of a complex, polycyclic volcano, which was originally proposed based on geomorphic and soil-development data.

  15. Prevalence rates of mental disorders in Chilean prisons.

    Directory of Open Access Journals (Sweden)

    Adrian P Mundt

    Full Text Available OBJECTIVE: High rates of mental disorders have been reported for prison populations worldwide, particularly in low- and middle-income countries (LMICs. The present study aimed to establish prevalence rates of mental disorders in Chilean prisoners. METHOD: A nationwide random sample of 1008 prisoners was assessed in 7 penal institutions throughout Chile. Twelve-month prevalence rates were established using the Composite International Diagnostic Interview (CIDI and compared to the prevalence rates previously published for the general population. RESULTS: Prevalence rates were 12.2% (95% CI, 10.2-14.1 for any substance use disorder, 8.3% (6.6-10.0 for anxiety disorders, 8.1% (6.5-9.8 for affective disorders, 5.7% (4.4-7.1 for intermittent explosive disorders, 2.2% (1.4-3.2 for ADHD of the adult, and 0.8% (0.3-1.3 for non-affective psychoses. Significantly higher prevalence rates among prisoners as compared to the general population in Chile were seen for major depression (6.1% vs. 3.7% males, Z=2.58, p<0.05 and illicit drug use (3.3% vs. 0.6% males with drug abuse, Z=2.04, p<0.05; 2.6% vs. 0.1% females with drug abuse, Z=5.36, p<0.001; 3.4% vs. 1.1% males with drug dependence, Z=3.70; p<0.001. Dysthymia (6.5% vs. 15.6%, Z=-2.39, p<0.05, simple (3.3% vs. 11.5%, Z=-3.13, p<0.001 and social phobias (3.9% vs. 9.7%, Z=2.38, p<0.05 were significantly less frequent in the female prison population than in the general population. One-year prevalence rates of alcohol abuse (2.3% vs. 3.9%; Z=-2.04; p<0.05 and dependence (2.7% vs. 8.2%; Z=-5.24; p<0.001 were less prevalent in the male prison population than in the general population. CONCLUSIONS: Service provision for prison populations in Chile should acknowledge high rates of depression and illicit drug use. Overall prevalence rates are lower than reported in other LMICs. Previous research in prison populations in LMICs might have overestimated prevalence rates of mental disorders.

  16. Population genetics of the Chilean frog Batrachyla Leptopus (Leptodactylidae

    Directory of Open Access Journals (Sweden)

    J.R. Formas

    2000-03-01

    Full Text Available Electrophoretic variation of proteins encoded by 14 loci was analyzed in eight (five continental and three insular populations of the Chilean leptodactylid frog Batrachyla leptopus. The overall proportion of polymorphic loci was estimated to be 18.7% and the average number of alleles per locus, 1.2, while observed and expected heterozygosities were 1.7 and 5.1%, respectively. The estimated coefficient of genetic identity was 0.940; the corresponding figure for genetic distance was 0.063. F-statistics analysis showed a total inbreeding coefficient (Fit of 0.855 and high levels of genetic subdivision (Fst = 0.596 as well as of inbreeding within populations (Fis = 0.640. However, there was only a moderate level of genetic differentiation (Fst = 0.181 between the insular group of populations and the continental group.A variação eletroforética de proteínas codificadas por 14 loci foi analisada em oito populações (5 continentais e 3 insulares da rã leptodactilídea chilena Batrachyla leptopus. A proporção geral de loci polimórficos foi estimada como sendo de 18,7% e o número médio de alelos por loco, 1,2, enquanto que as heterozigosidades observada e esperada foram 1,7 e 5,1%, respectivamente. O coeficiente esperado de identidade genética foi 0,940; o número correspondente para a distância genética foi 0,063. A análise estatística F mostrou um coeficiente de endogamia total (Fit de 0,855 e altos níveis de subdivisão genética (Fst = 0,596, assim como de endogamia dentro das populações (Fis = 0,640. Contudo, houve apenas um nível moderado de diferenciação genética (Fst = 0,181 entre o grupo insular de populações e o grupo continental.

  17. Amino acid biogeo- and stereochemistry in coastal Chilean sediments

    Science.gov (United States)

    Lomstein, Bente Aa.; Jørgensen, Bo B.; Schubert, Carsten J.; Niggemann, Jutta

    2006-06-01

    The spatial distribution of total hydrolysable amino acids (THAA) and amino acid enantiomers ( D- and L-forms) was investigated in sediments underlying two contrasting Chilean upwelling regions: at ˜23 °S off Antofagasta and at ˜36 °S off Concepción. The contribution of amino acids to total organic carbon (%T AAC: 7-14%) and total nitrogen (%T AAN: 23-38%) in surface sediments decreased with increasing water depth (from 126 to 1350 m) indicating that organic matter becomes increasingly decomposed in surface sediments at greater water depth. Changes in the ratio between the protein amino acid aspartate and its non-protein degradation product β-alanine confirmed this observation. Furthermore, estimates of THAA mineralization showed that sedimentary amino acid reactivity decreased with both increasing water depth as well as progressive degradation status of the organic matter that was incorporated into the sediment. Reactivity of organic matter in the sediment was also assessed using the Degradation Index (DI) developed by [Dauwe, B., Middelburg, J.J., 1998. Amino acids and hexosamines as indicators of organic matter degradation state in North Sea sediments. Limnol. Oceanogr.43, pp. 782-798.]. Off Concepción, DI was successfully applied to examine the degradation status of sedimentary organic matter at different water depths. However, unexpected results were obtained at the Antofagasta stations as DI increased with sediment depth, suggesting more degraded organic matter at the surface than deeper in the cores. The contribution of peptidoglycan amino acids to THAA was estimated from the concentrations of D-aspartate, D-glutamic acid, D-serine, and D-alanine. Peptidoglycan amino acids accounted for >18% of THAA in all investigated samples. In surface sediments peptidoglycan amino acids accounted for a progressively larger fraction of THAA at increasing water depths (up to >26%). Further, the contribution of peptidoglycan amino acids to THAA increased with

  18. Last millenium environmental changes in Lake Bertrand sediments, Chilean Patagonia

    Science.gov (United States)

    Sacré, V.; Fagel, N.; Schmidt, S.; Alvarez, D.; Araneda, A.; Urrutia, R.

    2012-04-01

    'W). The identification of the diatom assemblages and its temporal variability in both lake sediments will help to identify the origin of those silica-rich layers. In addition, further sedimentological analyses are in progress to better characterize the sediment deposition models. This research was funded by Chilean Fondecyt project number 1070508 and Belgian projects (FNRS proposal 1360 2007-2010, ULg CFRA 1060 2009-2010).

  19. Guanaco traces and hunting strategies at Alto Patache North Chilean fog oasis

    Science.gov (United States)

    Larrain, H.; Cereceda, P.; Pérez, L.

    2010-07-01

    1. In foregoing Fog Conferences, some of us have made explicit the rich botanic and faunistic inventory to be found at this Chilean Fog site. This was specially apparent under strong ENSO conditions, as it happened in 1997/98 in the area. Among the mammal biggest species represented, the guanaco (Lama guanicoe Müller) merits special mention. Clear traces of their presence and eventual hunting and slaughtering by primitive populations have survived until present times. Among them, the myriads of guanaco trails still covering practically all the slopes along the foggy area, close to the sea, and their wollowing and defecating places are found. Also, although less studied, plant eating traces left behind by roaming camelids can be seen. 2. Guanaco hunting traces still visible at Alto Patache can be portrayed differently through : A) Analysis of lithic artifacts used as arms in hunting operations; B) Botanic response to animal attack; C) Examination of topographic traits used by primitive man in guanaco hunting strategies. A. Hundreds of lithic instruments made of stone, were abandoned by hunters in situ, some of them were intact, some fragmented, which would demonstrate a direct relationship with hunting and slaughtering, and also their elaboration in workshops at place. Lithic points, scrapers and knives were found at places specially apt for hunting or slaughtering activities. Total isolation of the mountain fog site previous to our arrival in 1996, favoured their conservation at place. B. Careful observation of some local plants showed clear traces of guanaco feeding habits. As a proof thereof, old cactus of the species Eulychnia iquiquensis show in their basal portions clear signals in the forms of scars, caused by the eating by guanacos. Guanaco faeces were found at the foot of Ephedra plants. Many dead Stipa ichu plants (Gramineae), in different areas of the oasis provide evidence of cutting close to their basis, caused by sharp guanaco tooth under severe food

  20. Magnetic minerals from volcanic Ultisols as heterogeneous Fenton catalysts

    International Nuclear Information System (INIS)

    This study was devoted to the evaluation of the effectiveness of Fenton catalysts, based on magnetically-concentrated portions of iron oxide-rich sand fractions from two magnetic Ultisols, derived from volcanic materials of southern Chile. The samples were labeled according to the municipality where the sample sites are geographically located, namely Metrenco and Collipulli, and were characterized with Moessbauer spectroscopy at 298 K and saturation magnetization (σ) measurements. Moessbauer data revealed a complex magnetic hyperfine structure for these magnetic portions from both soil-sand materials, suggesting relatively complex mineral assemblages. The monitored rate of H2O2 decomposition via heterogeneous Fenton reaction revealed that materials from the Collipulli soil are more efficient Fenton catalyst than are those from the Metrenco soil. The reasons for these differences are from now on being explored on basis of a more detailed chemical investigation of these samples.

  1. Mineral mapping on the Chilean-Bolivian Altiplano using co-orbital ALI, ASTER and Hyperion imagery: Data dimensionality issues and solutions

    Science.gov (United States)

    Hubbard, B.E.; Crowley, J.K.

    2005-01-01

    Hyperspectral data coverage from the EO-1 Hyperion sensor was useful for calibrating Advanced Land Imager (ALI) and Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) images of a volcanic terrane area of the Chilean-Bolivian Altiplano. Following calibration, the ALI and ASTER datasets were co-registered and joined to produce a 13-channel reflectance cube spanning the Visible to Short Wave Infrared (0.4-2.4 ??m). Eigen analysis and comparison of the Hyperion data with the ALI + ASTER reflectance data, as well as mapping results using various ALI+ASTER data subsets, provided insights into the information dimensionality of all the data. In particular, high spectral resolution, low signal-to-noise Hyperion data were only marginally better for mineral mapping than the merged 13-channel, low spectral resolution, high signal-to-noise ALI + ASTER dataset. Neither the Hyperion nor the combined ALI + ASTER datasets had sufficient information dimensionality for mapping the diverse range of surface materials exposed on the Altiplano. However, it is possible to optimize the use of the multispectral data for mineral-mapping purposes by careful data subsetting, and by employing other appropriate image-processing strategies.

  2. Guanamiru, l'homme-volcan

    OpenAIRE

    Collot, Michel

    2016-01-01

    Comment fabriquer un volcan portatif ? Où trouver un cratère en kit ? Comment faut-il l’emballer pour qu’il supporte un voyage transcontinental ? Où peut-on assister à des éruptions de charité ? Comment devient-on un homme-volcan ? Y a-t-il un remède contre les crises de mégalomanie éruptive ? A toutes ces questions brûlantes, Supervielle a tenté de répondre dans son premier roman, L'Homme de la pampa. C’est l’époque où, après avoir refoulé pendant près de quarante ans sous une croûte épaisse...

  3. Anomalous diffusion of volcanic earthquakes

    CERN Document Server

    Abe, Sumiyoshi

    2015-01-01

    Volcanic seismicity at Mt. Etna is studied. It is found that the associated stochastic process exhibits a subdiffusive phenomenon. The jump probability distribution well obeys an exponential law, whereas the waiting-time distribution follows a power law in a wide range. Although these results would seem to suggest that the phenomenon could be described by temporally-fractional kinetic theory based on the viewpoint of continuous-time random walks, the exponent of the power-law waiting-time distribution actually lies outside of the range allowed in the theory. In addition, there exists the aging phenomenon in the event-time averaged mean squared displacement, in contrast to the picture of fractional Brownian motion. Comments are also made on possible relevances of random walks on fractals as well as nonlinear kinetics. Thus, problems of volcanic seismicity are highly challenging for science of complex systems.

  4. Source mechanisms of volcanic tsunamis.

    Science.gov (United States)

    Paris, Raphaël

    2015-10-28

    Volcanic tsunamis are generated by a variety of mechanisms, including volcano-tectonic earthquakes, slope instabilities, pyroclastic flows, underwater explosions, shock waves and caldera collapse. In this review, we focus on the lessons that can be learnt from past events and address the influence of parameters such as volume flux of mass flows, explosion energy or duration of caldera collapse on tsunami generation. The diversity of waves in terms of amplitude, period, form, dispersion, etc. poses difficulties for integration and harmonization of sources to be used for numerical models and probabilistic tsunami hazard maps. In many cases, monitoring and warning of volcanic tsunamis remain challenging (further technical and scientific developments being necessary) and must be coupled with policies of population preparedness.

  5. Understanding Volcanic Conduit Dynamics: from Experimental Fragmentation to Volcanic Eruptions

    Science.gov (United States)

    Arciniega-Ceballos, A.; Alatorre-Ibarguengoitia, M. A.; Scheu, B.; Dingwell, D. B.

    2011-12-01

    The investigation of conduit dynamics at high pressure, under controlled laboratory conditions is a powerful tool to understand the physics behind volcanic processes before an eruption. In this work, we analyze the characteristics of the seismic response of an "experimental volcano" focusing on the dynamics of the conduit behavior during the fragmentation process of volcanic rocks. The "experimental volcano" is represented by a shock tube apparatus, which consists of a low-pressure voluminous tank (3 x 0.40 m), for sample recovery; and a high-pressure pipe-like conduit (16.5 x 2,5 cm), which represents the volcanic source mechanism, where rock samples are pressurized and fragmented. These two serial steel pipes are connected and sealed by a set of diaphragms that bear pressures in a range of 4 to 20 MPa. The history of the overall process of an explosion consists of four steps: 1) the slow pressurization of the pipe-like conduit filled with solid pumice and gas, 2) the sudden removal of the diaphragms, 3) the rapid decompression of the system and 4) the ejection of the gas-particle mixture. Each step imprints distinctive features on the microseismic records, reflecting the conduit dynamics during the explosion. In this work we show how features such as waveform characteristics, the three components of the force system acting on the conduit, the independent components of the moment tensor, the volumetric change of the source mechanism, the arrival time of the shock wave and its velocity, are quantified from the experimental microseismic data. Knowing these features, each step of the eruptive process, the conduit conditions and the source mechanism characteristics can be determined. The procedure applied in this experimental approach allows the use of seismic field data to estimate volcanic conduit conditions before an eruption takes place. We state on the hypothesis that the physics behind the pressurization and depressurization process of any conduit is the same

  6. Amazonian volcanic activity at the Syrtis volcanic province, Mars

    Science.gov (United States)

    Platz, Thomas; Jodlowski, Piotr; Fawdon, Peter; Michael, Greg; Tanaka, Kenneth

    2014-05-01

    The Syrtis Major volcanic province, including the entire Syrtis Major Planum, is located near the Martian highland/lowland transitional zone west of Isidis Planitia. It covers ≡7.4×105 km2 and contains two low-shield volcanic edifices with N-S elongated calderas named Nili and Meroe Paterae. The estimated thickness of erupted material in the province ranges from approximately 0.5 km to 1.0 km with a total volume of about 1.6-3.2×105 km3 [1]. The timing of volcanic activity in the Syrtis Major volcanic province has been suggested to be restricted to the Hesperian Period [1-4]. In the geological map of Greeley and Guest [2], volcanic material of Syrtis Major was assigned an Hesperian age based on the density of observed craters larger than 5 km in diameter. Using the same crater density range, recent studies of Hiesinger et al. [1] and Tanaka et al. [3] and Tanaka et al. [4] assigned an Early Hesperian and Early to Late Hesperian age, respectively, for the entire province. In this study we mapped lava flows, lava channels, and major lava-flow margins and report model ages for lava-flow formation and caldera segments of Nili and Meroe Paterae. The objective of this ongoing survey is to better understand the eruption frequency of this volcanic province. In total, we mapped 67 lava flows, caldera segments, and intra-crater fillings of which 55 were dated. Crater size-frequency distributions (CSFD) were mapped on HRSC and CTX imagery using CraterTools [5]. CSFDs were analyzed and model ages determined in Craterstats [6] using the production and chronology functions of Ivanov [7] and Hartmann and Neukum [8], respectively. A detailed description of the utilization of the crater-counting technique and its limitations with respect to small-scale mapping is given in Platz et al. [9]. Model ages range between 838 Ma (Middle Amazonian) to 3.6 Ga (Late Hesperian). In our survey, a broad age peak occurs between 2 to 2.6 Ga, continuously declining thereafter. We note that

  7. Uranium deposits in volcanic rocks

    International Nuclear Information System (INIS)

    Twenty-eight papers were presented at the meeting and two additional papers were provided. Three panels were organized to consider the specific aspects of the genesis of uranium deposits in volcanic rocks, recognition criteria for the characterization of such deposits, and approaches to exploration. The papers presented and the findings of the panels are included in the Proceedings. Separate abstracts were prepared for each of these papers

  8. Comparing Sociodemographic Factors Associated with Disability between Immigrants and the Chilean-Born: Are There Different Stories to Tell?

    OpenAIRE

    Baltica Cabieses; Pickett, Kate E.; Helena Tunstall

    2012-01-01

    This study explored a range of sociodemographic factors associated with disability among international immigrants in Chile, and compared them to the Chilean-born. Secondary data analysis of the Chilean population-based survey CASEN-2006 was conducted (268,873 participants). Main health outcomes: any disability and six different types of disability: visual, hearing, learning, physical, psychiatric and speaking (binary outcomes). Sociodemographic variables: Demographic factors (age, sex, marita...

  9. Fishing the future. A snapshot of the Chilean TURFs through the lens of fishers and key stakeholders‟ perceptions

    OpenAIRE

    Ueyonahara, Jorge

    2012-01-01

    Overfishing is not an exclusive topic of big fishing industry. Overfishing by small-scale fishers is also happening. The Territorial Use of Rights – TURFs was implemented in Chile to protect the Chilean abalone from overfishing. Through the implementation of the TURFs Chilean abalone are no longer threatened by overfishing. The challenge to protect the resource thus seems to be solved. However, while some problems are solved others persist or new ones arise. The thesis explores the discourses...

  10. Volcanism in Elysium Planitia, Mars

    Science.gov (United States)

    Mouginis-Mark, P. J.

    1984-01-01

    Geomorphic mapping revealed that the three volcanic constructs within Elysium Planitia (Hecates Tholus, elysium Mons and Albor Tholus) are very different in their overall morphology and represent three distinct types of martian volcano. Hecates Tholus was found to possess the most likely possible example of a young, explosively generated, air fall deposit, while the volume of magma erupted from Elysium Mons appears to have been orders of magnitude larger than that erupted from Albor Tholus. A primary aim of the regional geological analysis of Elysium Planitia is to further understand the volcanic and tectonic evolution of the area by the identification and interpretation of individual lava flows and their source vents. Lava flow size, spatial distribution, flow direction and the stratigraphic relationships of these lava flows to adjacent structural features were all measured. The topographic form of Elysium Mons has totally controlled the flow direction of lava flows within Elysium Planitia. Lava flows from Elysium Mons can be traced for distances of 150 to 250 km in a radial direction from the volcano. Parasitic vents located beyond the recognizable volcanic construct also conform to this radial pattern. A second unusual characteristic of the Elysium Planitia region is the high frequency of occurrence of sinuous channels that are morphologically similar to lunar sinuous rilles.

  11. Bayesian analysis of volcanic eruptions

    Science.gov (United States)

    Ho, Chih-Hsiang

    1990-10-01

    The simple Poisson model generally gives a good fit to many volcanoes for volcanic eruption forecasting. Nonetheless, empirical evidence suggests that volcanic activity in successive equal time-periods tends to be more variable than a simple Poisson with constant eruptive rate. An alternative model is therefore examined in which eruptive rate(λ) for a given volcano or cluster(s) of volcanoes is described by a gamma distribution (prior) rather than treated as a constant value as in the assumptions of a simple Poisson model. Bayesian analysis is performed to link two distributions together to give the aggregate behavior of the volcanic activity. When the Poisson process is expanded to accomodate a gamma mixing distribution on λ, a consequence of this mixed (or compound) Poisson model is that the frequency distribution of eruptions in any given time-period of equal length follows the negative binomial distribution (NBD). Applications of the proposed model and comparisons between the generalized model and simple Poisson model are discussed based on the historical eruptive count data of volcanoes Mauna Loa (Hawaii) and Etna (Italy). Several relevant facts lead to the conclusion that the generalized model is preferable for practical use both in space and time.

  12. Preliminary geologic map of the Sleeping Butte volcanic centers

    International Nuclear Information System (INIS)

    The Sleeping Butte volcanic centers comprise two, spatially separate, small-volume (3) basaltic centers. The centers were formed by mildly explosive Strombolian eruptions. The Little Black Peak cone consists of a main scoria cone, two small satellitic scoria mounds, and associated lobate lava flows that vented from sites at the base of the scoria cone. The Hidden Cone center consists of a main scoria cone that developed on the north-facing slope of Sleeping Butte. The center formed during two episodes. The first included the formation of the main scoria cone, and venting of aa lava flows from radial dikes at the northeast base of the cone. The second included eruption of scoria-fall deposits from the summit crater. The ages of the Little Black Peak and the Hidden Cone are estimated to be between 200 to 400 ka based on the whole-rock K-Ar age determinations with large analytical undertainty. This age assignment is consistent with qualitative observations of the degree of soil development and geomorphic degradation of volcanic landforms. The younger episode of the Hidden Cone is inferred to be significantly younger and probably of Late Pleistocene or Holocene age. This is based on the absence of cone slope rilling, the absence of cone-slope apron deposits, and erosional unconformity between the two episodes, the poor horizon- development of soils, and the presence of fall deposits on modern alluvial surfaces. Paleomagnetic data show that the centers record similar but not identical directions of remanent magnetization. Paleomagnetic data have not been obtained for the youngest deposits of the Hidden Cone center. Further geochronology, soils, geomorphic, and petrology studies are planned of the Sleeping Butte volcanic centers 20 refs., 3 figs

  13. "One of the Most Uniform Races of the Entire World": Creole Eugenics and the Myth of Chilean Racial Homogeneity.

    Science.gov (United States)

    Walsh, Sarah

    2015-11-01

    This article illuminates why Nicolás Palacios's 1904 monograph, Raza chilena: Libro escrito por un Chileno i para los Chilenos [Chilean Race: A Book Written by a Chilean for Chileans], is central to the creation of a myth of Chilean racial homogeneity at the turn of the twentieth century. Placing Palacios in the context of Latin American eugenic discourse, it demonstrates how he selected a specific racial origin story in order to accommodate his belief in racial hierarchy while also depicting race mixing in a positive light. Specifically, the article highlights how the myth of Chilean racial homogeneity elided the difference between the term "mestizo," which was applied to people of mixed racial heritage, and "white." I contend that Palacios sought to differentiate Chileans from other Latin Americans by emphasizing their racial distinctiveness. The article therefore highlights that Latin American eugenics was concerned with the creation of national narratives that historicized particular racial mixtures in order to reify and affirm national differences. As such, it connects to literature regarding the history of eugenics, race, nation, and the creation of whiteness. PMID:25733067

  14. "One of the Most Uniform Races of the Entire World": Creole Eugenics and the Myth of Chilean Racial Homogeneity.

    Science.gov (United States)

    Walsh, Sarah

    2015-11-01

    This article illuminates why Nicolás Palacios's 1904 monograph, Raza chilena: Libro escrito por un Chileno i para los Chilenos [Chilean Race: A Book Written by a Chilean for Chileans], is central to the creation of a myth of Chilean racial homogeneity at the turn of the twentieth century. Placing Palacios in the context of Latin American eugenic discourse, it demonstrates how he selected a specific racial origin story in order to accommodate his belief in racial hierarchy while also depicting race mixing in a positive light. Specifically, the article highlights how the myth of Chilean racial homogeneity elided the difference between the term "mestizo," which was applied to people of mixed racial heritage, and "white." I contend that Palacios sought to differentiate Chileans from other Latin Americans by emphasizing their racial distinctiveness. The article therefore highlights that Latin American eugenics was concerned with the creation of national narratives that historicized particular racial mixtures in order to reify and affirm national differences. As such, it connects to literature regarding the history of eugenics, race, nation, and the creation of whiteness.

  15. Mitigate and Assess risk from Volcanic Impact on Terrain and human Activities: the FP7 MIAVITA project

    OpenAIRE

    Thierry, Pierre; Vagner, Amélie; Fontaine, Mélanie

    2012-01-01

    Volcanic eruptions are one of the most impressive, violent and dramatic agents of change on Earth. Volcanic emissions (gas and ashes) can widely affect human health and disturb air-traffic and little is known about their impact on agriculture. Some phenomena constitute therefore a multi-level threat to human societies and environment. Nevertheless, soils fertility, amongst other characteristics, often attracts populations, which settle on volcanoes flanks, creating, by the conjunction of haza...

  16. Reappraisal of the significance of volcanic fields

    Science.gov (United States)

    Cañón-Tapia, Edgardo

    2016-01-01

    "Volcanic field" is a term commonly used to loosely describe a group of volcanoes. Often, it is implicitly assumed that the volcanoes on a volcanic field are small, monogenetic and dominantly basaltic, but none of those attributes is indispensable on some definitions of the term. Actually, the term "volcanic field" can be used to describe a group of purely monogenetic edifices, a group of mixed monogenetic and polygenetic edifices, or even a group formed only by purely polygenetic edifices. Differences between each of those alternatives might be important, but the extent to which those differences are truly relevant remains still to be explored. Furthermore, there are several limitations on the current knowledge of this type of volcanic activity that explain the lack of a comprehensive effort to study volcanic fields in global contexts. In this work, issues concerning current definitions of a volcanic field are examined, and some criteria that can be used to distinguish volcanic fields from non-field volcanoes are suggested. Special attention is given to the role played by spatial scale on such a distinction. Also, the tectonic implications of their spatial distribution are explored. In particular, it is shown that volcanic fields are an important component of volcanic activity at a global scale that is closely associated to diffuse plate boundaries, and might well be considered the archetypical volcanic form of such tectonic scenarios.

  17. Recalibrated mariner 10 color mosaics: Implications for mercurian volcanism

    Science.gov (United States)

    Robinson, M.S.; Lucey, P.G.

    1997-01-01

    Recalibration of Mariner 10 color image data allows the identification of distinct color units on the mercurian surface. We analyze these data in terms of opaque mineral abundance, iron content, and soil maturity and find color units consistent with the presence of volcanic deposits on Mercury's surface. Additionally, materials associated with some impact craters have been excavated from a layer interpreted to be deficient in opaque minerals within the crust, possibly analogous to the lunar anorthosite crust. These observations suggest that Mercury has undergone complex differentiation like the other terrestrial planets and the Earth's moon.

  18. Geochemical signatures of the diffuse CO2 emission from Brava volcanic system, Cape Verde

    Science.gov (United States)

    Rodriguez, F.; Bandomo, Z.; Barros, I.; Dias Fonseca, J.; Fernandes, P.; Rodrigues, J.; Melian Rodriguez, G.; Padron, E.; Dionis, S.; Sonia, S.; Gonçalves, A.; Fernandes, A.; Hernandez Perez, P. A.; Perez, N.

    2010-12-01

    Brava (67 km2) the smallest of the populated Cape Verde islands, lies at the southwestern end of the archipelagic crescent. Brava volcanic system has no documented historical eruptions, but its youthful volcanic morphology and the fact that earthquake swarms still occur indicate the potential for future eruptions. A geochemical survey of diffuse gas emissions was carried out in Brava island during February and March 2010. For this survey 228 sampling sites were selected all over the island to perform soil CO2 efflux measurements, using a portable accumulation chamber and an IR sensor, and soil temperature measurements at a depth of 30-50 cm. Soil gas samples were collected at 40 cm depth for chemical (He, H2, N2, CO2, CH4, Ar and O2) and isotopic (δ13C-CO2) analysis in 32 selected sampling sites. CO2 efflux values ranged from non-detectable up to 1.343 g m-2 d-1. To quantify the total diffuse CO2 emission from Brava volcanic system, a CO2 efflux map was constructed using sequential Gaussian simulations (sGs). Most of the studied area showed background levels of CO2 efflux (˜2 g m-2 d-1), while peak levels (>1300 g m-2 d-1) were mainly identified at Vinagre and Baleia areas. The total diffuse CO2 output from Brava volcanic system was estimated about 41.6 t d-1. The analysis of the carbon isotopic signature of the CO2 in the soil atmosphere provides an insight for evaluating the origin of the diffuse CO2 emission. Observed δ13C-CO2 values ranged from -20.86 to -1.26 ‰. A binary plot of CO2 concentrations versus δ13C-CO2 values allows us to represent three major geochemical reservoirs (atmospheric air, volcanic gas, and biogenic gas) and their related mixing lines. The chemical and isotopic analysis of Brava soil gas samples suggest a mixing with deep-seated CO2 and biogenic gas for the diffuse CO2 emission from Brava volcanic system. The lack of visible volcanic gas emission in Brava highlights the importance of monitoring diffuse CO2 emission to improve its

  19. Volcanic processes in the Solar System

    Science.gov (United States)

    Carr, M.H.

    1987-01-01

    This article stresses that terrestrial volcanism represents only part of the range of volcanism in the solar system. Earth processes of volcanicity are dominated by plate tectonics, which does not seem to operate on other planets, except possibly on Venus. Lunar volcanicity is dominated by lava effusion at enormous rates. Mars is similar, with the addition to huge shield volcanoes developed over fixed hotspots. Io, the moon closest to Jupiter, is the most active body in the Solar System and, for example, much sulphur and silicates are emitted. The eruptions of Io are generated by heating caused by tides induced by Jupiter. Europa nearby seems to emit water from fractures and Ganymede is similar. The satellites of Saturn and Uranus are also marked by volcanic craters, but they are of very low temperature melts, possibly of ammonia and water. The volcanism of the solar system is generally more exotic, the greater the distance from Earth. -A.Scarth

  20. Environmental adaptability of Canavalia virosa and Flemingia congesta to sandy ash soil of Merapi Volcano, Java

    OpenAIRE

    S. S. Wardoyo; A. Z. P. B. Santosa

    2016-01-01

    Studies on volcanic ash of Mount Merapi erupted in 2010 are limited to only characterization of mineralogical, physical, chemical, and biological properties of the volcanic ash. In order to speed up rehabilitation of soils affected by the volcanic ash, it is necessary to study the application of suitable plant species, which is called bio-mechanic conservation. The purpose of this study was to test the environmental adaptability of Canavalia virosa and Flemingia congesta in sandy soil covered...

  1. Spanish and Chilean Standardizations of the Personality Assessment Inventory: the Influence of Sex.

    Science.gov (United States)

    Ortiz-Tallo, Margarita; Cardenal, Violeta; Ferragut, Marta; Santamaría, Pablo

    2015-01-01

    There is growing interest in the adaptation of psychological questionnaires in different countries, due to the need for cross-cultural research using the same tests adapted to diverse populations. This paper presents the standardization of the Personality Assessment Inventory (PAI; Morey, 1991, 2007) in Spain and Chile (both Spanish-speaking countries). The Spanish sample was made up of 940 people (461 men and 479 women), and the Chilean sample of 569 people (231 men and 338 women). Results revealed that the Chilean means were higher than those of the Spanish sample at confidence level 99.9%, although the associated effect sizes were generally small to moderate (partial eta-square between 0.008 and 0.187). Sex differences in the variables evaluated were commented on, and the importance of cross-cultural research and the influence of sex on personality and psychopathology variables were discussed.

  2. Socioeconomic Status and Internalizing Symptoms in Chilean Children: Does Reserve Capacity Matter?

    Science.gov (United States)

    Martinez, Suzanna M; Castillo, Marcela; Lozoff, Betsy; Gahagan, Sheila

    2016-01-01

    Informed by the reserve capacity model, we examined pathways between socioeconomic status (SES) and internalizing symptoms (IS) in 1119 Chilean 10-year-olds. Mediators included parental disciplinary style and reserve capacity resources (RCR), namely home environment, parent-child engagement, and self-esteem, and conduct problems. Using structural equation modeling, the model was stratified by gender. For boys, the SES-IS relationship was mediated by the home environment and parental disciplinary style. For girls, the SES-IS relationship was mediated by the home environment, parent-child engagement, self-esteem, and conduct problems. Findings suggest different RCR may protect against IS in a sample of Chilean children. PMID:27123471

  3. Psychometric properties of the "Spanish Burnout Inventory" in Chilean professionals working to physical disabled people.

    Science.gov (United States)

    Gil-Monte, Pedro R; Olivares Faúndez, Víctor E

    2011-05-01

    While the most commonly employed burnout measure has been the Maslach Burnout Inventory (MBI), researchers have been troubled by some of the psychometric limitations of this instrument. The aim of this study was to analyze the psychometric properties of the "Spanish Burnout Inventory" (SBI). The psychometric properties were analysed with data from a sample of 277 Chilean professionals working to physical disabled people. The psychometric properties of the SBI were examined through the following analyses: confirmatory factor analysis, reliability Cronbach's alpha, and concurrent validity with the MBI. The hypothesized four factor model obtained an adequate data fit for the sample (chi2(164) = 285.32, p burnout in the Chilean cultural context.

  4. Volcanic caves of East Africa - an overview

    OpenAIRE

    Jim W. Simons

    1998-01-01

    Numerous Tertiary to recent volcanoes are located in East Africa. Thus, much of the region is made up volcanic rock, which hosts the largest and greatest variety of East Africas caves. Exploration of volcanic caves has preoccupied members of Cave Exploration Group of East Africa (CEGEA) for the past 30 years. The various publications edited by CEGEA are in this respect a treasure troves of speleological information. In the present paper an overview on the most important volcanic caves and are...

  5. Sensitivity of atmospheric CO2 and climate to explosive volcanic eruptions

    Directory of Open Access Journals (Sweden)

    C. C. Raible

    2011-08-01

    Full Text Available Impacts of low-latitude, explosive volcanic eruptions on climate and the carbon cycle are quantified by forcing a comprehensive, fully coupled carbon cycle-climate model with pulse-like stratospheric aerosol optical depth changes. The model represents the radiative and dynamical response of the climate system to volcanic eruptions and simulates a decrease of global and regional atmospheric surface temperature, regionally distinct changes in precipitation, a positive phase of the North Atlantic Oscillation, and a decrease in atmospheric CO2 after volcanic eruptions. The volcanic-induced cooling reduces overturning rates in tropical soils, which dominates over reduced litter input due to soil moisture decrease, resulting in higher land carbon inventories for several decades. The perturbation in the ocean carbon inventory changes sign from an initial weak carbon sink to a carbon source. Positive carbon and negative temperature anomalies in subsurface waters last up to several decades. The multi-decadal decrease in atmospheric CO2 yields a small additional radiative forcing that amplifies the cooling and perturbs the Earth System on longer time scales than the atmospheric residence time of volcanic aerosols. In addition, century-scale global warming simulations with and without volcanic eruptions over the historical period show that the ocean integrates volcanic radiative cooling and responds for different physical and biogeochemical parameters such as steric sea level or dissolved oxygen. Results from a suite of sensitivity simulations with different magnitudes of stratospheric aerosol optical depth changes and from global warming simulations show that the carbon cycle-climate sensitivity γ, expressed as change in atmospheric CO2 per unit change in global mean surface temperature, depends on the magnitude and temporal evolution of the perturbation, and time scale of interest. On decadal time scales, modeled γ is several times larger for a

  6. Sensitivity of atmospheric CO2 and climate to explosive volcanic eruptions

    Directory of Open Access Journals (Sweden)

    C. C. Raible

    2011-03-01

    Full Text Available Impacts of low-latitude, explosive volcanic eruptions on climate and the carbon cycle are quantified by forcing a comprehensive, fully coupled carbon cycle-climate model with pulse-like stratospheric sulfur release. The model represents the radiative and dynamical response of the climate system to volcanic eruptions and simulates a decrease of global and regional atmospheric surface temperature, regionally distinct changes in precipitation, a positive phase of the North Atlantic Oscillation, and a decrease in atmospheric CO2 after volcanic eruptions. The volcanic-induced cooling reduces overturning rates in tropical soils, which dominates over reduced litter input due to soil moisture decrease, resulting in higher land carbon inventories for several decades. The perturbation in the ocean carbon inventory changes sign from an initially weak carbon sink to a carbon source. Positive carbon and negative temperature anomalies in subsurface waters last up to several decades. The multi-decadal decrease in atmospheric CO2 yields an additional radiative forcing that amplifies the cooling and perturbs the Earth System on much longer time scales than the atmospheric residence time of volcanic aerosols. In addition, century-scale global warming simulations with and without volcanic eruptions over the historical period show that the ocean integrates volcanic radiative cooling and responds for different physical and biogeochemical parameters such as steric sea level or dissolved oxygen. Results from a suite of sensitivity simulations with different amounts of sulfur released and from global warming simulations show that the carbon cycle-climate sensitivity γ, expressed as change in atmospheric CO2 per unit change in global mean surface temperature, depends on the perturbation. On decadal time scales, modeled γ is several times larger for a Pinatubo-like eruption than for the industrial period and for a high emission, 21st century scenario.

  7. Soil texture; 1 : 500 000

    International Nuclear Information System (INIS)

    The characteristics of soil texture are based on an abundant database of the agricultural and forest soils. The character of the texture of the upper soil horizons is assessed. The colour scale represents the classes of texture, and the raster distinguishes the individual classes of stoniness (in mountain ranges) or graveliness in the river alluvia. Soils with at least 10 % of area representation of rock basement are classified as very rocky. Very rocky soils are mostly rankers to Lithosols in the mountain areas of Slovakia. Medium stony are Cambisols to rankers on the crystalline rocks and volcanic complexes. The relatively heaviest soils are to be found in the Vychodoslovenska nizina Lowland, the lightest soils occur in the Zahorska nizina Lowland with prevalence of soils on aeolian sands. (authors)

  8. Original footage of the Chilean miners with manganism published in Neurology in 1967.

    Science.gov (United States)

    Miranda, Marcelo; Bustamante, M Leonor; Mena, Francisco; Lees, Andrew

    2015-12-15

    Manganism has captured the imagination of neurologists for more than a century because of its similarities to Parkinson disease and its indirect but seminal role in the "l-dopa miracle." We present unpublished footage of the original case series reported in Neurology® in 1967 by Mena and Cotzias depicting the typical neurologic signs of manganism in 4 Chilean miners and their response to high doses of l-dopa. PMID:26668239

  9. Original footage of the Chilean miners with manganism published in Neurology in 1967.

    Science.gov (United States)

    Miranda, Marcelo; Bustamante, M Leonor; Mena, Francisco; Lees, Andrew

    2015-12-15

    Manganism has captured the imagination of neurologists for more than a century because of its similarities to Parkinson disease and its indirect but seminal role in the "l-dopa miracle." We present unpublished footage of the original case series reported in Neurology® in 1967 by Mena and Cotzias depicting the typical neurologic signs of manganism in 4 Chilean miners and their response to high doses of l-dopa.

  10. Breast bud detection: a validation study in the Chilean Growth Obesity Cohort Study

    OpenAIRE

    Pereira, Ana; Garmendia, María Luisa; González, Daniela; Kain, Juliana; Mericq, Verónica; Uauy, Ricardo; Corvalán, Camila

    2014-01-01

    Background Early puberty onset has been related to future chronic disease; however breast bud assessment in large scale population studies is difficult because it requires trained personnel. Thus our aim is to assess the validity of self and maternal breast bud detection, considering girl’s body mass index (BMI) and maternal education. Methods In 2010, 481 girls (mean age = 7.8) from the Growth and Obesity Chilean Cohort Study were evaluated by a nutritionist trained in breast bud detection. ...

  11. High genetic diversity in a small population: the case of Chilean blue whales

    OpenAIRE

    Torres-Florez, Juan P; Hucke-Gaete, Rodrigo; Rosenbaum, Howard; Christian C Figueroa

    2014-01-01

    It is generally assumed that species with low population sizes have lower genetic diversities than larger populations and vice versa. However, this would not be the case for long-lived species with long generation times, and which populations have declined due to anthropogenic effects, such as the blue whale (Balaenoptera musculus). This species was intensively decimated globally to near extinction during the 20th century. Along the Chilean coast, it is estimated that at least 4288 blue whale...

  12. Paradoxes of participatory democracy: citizen participation, collective action and political influence in a Chilean environmental conflict

    OpenAIRE

    Spoerer, Matilde

    2014-01-01

    This article proposes a critical analysis of the impacts of participatory democracy in public action and collective action. Based on the study of the Barrancones environmental conflict in Chile (2007-2010), the aim is to analyze how transformations and innovations in Chilean environmental law regarding citizen participation have had an ambivalent impact. On one hand, institutional citizen participation appears to be an instrument of economic and authoritarian logic to legitimize energy policy...

  13. Uncommon social trajectories: Chilean low-income adolescents with reading skills

    Directory of Open Access Journals (Sweden)

    Iván Ortiz

    2013-07-01

    Full Text Available It is generally believed that students from low-income families are less successful at school, as indicated by theories of social reproduction. This article focuses on Chilean students that, in spite of their social background, have performed well in the Programme for International Student Assessment (PISA 2009. Using logistic regression analysis we identify factors associated with academic achievement in reading. Results show that student variables have a greater explanatory value than family and school variables.

  14. Chemotaxonomic Fingerprinting of Chilean Lichens Through Maldi and Electrospray Ionization Mass Spectrometry

    OpenAIRE

    Leonardo Silva Santos; Maria del Pilar Camarantin Soriano; Yaneris Mirabal-Gallardo; Veronica Carrasco-Sanchez; Fabiane Manke Nachtigall; Iris Pereira; Eugenia Pereira

    2015-01-01

    The aim of this work was to study a fast, new, sensitive, and simple method for the chemotaxonomic classification of Chilean lichens (Teloschistes chrysophthalmus, Ramalina farinacea, Usnea pusilla, Ramalina chilensis and Stereocaulon ramulosum) using MALDI-TOF-MS and UPLC-ESI(-)-MS data. Lichens soluble proteins fingerprints were acquired by MALDI-TOF-MS and they were analyzed by chemometric (PCA). Lichens organic extracts fingerprints were obtained by UPLC-ESI(-)-MS. MALDI-TOF-MS associated...

  15. Intercultural journalism: Peruvian and Bolivian representation in the Chilean daily press news

    OpenAIRE

    Browne-Sartori, Rodrigo-Francisco; Baessolo-Stiven, Ricardo-Alberto; Silva-Echeto, Víctor-Manuel

    2010-01-01

    This article examines the processes through which the massive press generates and represents the cultural discourses of two of the most polemic migrant groups coexisting nowadays in Chile: Peruvians and Bolivians. The representation that the communication media carries out regarding the studied cultures strongly influences the imaginaries of the Chilean audiences. That calls for special concern so as to propose the necessary spaces for intercultural exchange as much in the media as in the soc...

  16. Democracy and Student Discontent: Chilean Student Protest in the Post-Pinochet Era

    OpenAIRE

    Peter M. M. Cummings; University of Notre Dame, Indiana

    2015-01-01

    Objective indicators suggest that economic and political conditions improved in Chile between the country’s democratization in 1990 and 2011. Average incomes increased, poverty rates decreased, and the number of positive reviews of Chilean democratic institutions rose. Despite this progress, massive student-led protest waves in 2006 and 2011 demonstrated high levels of subjective discontent in Chile. This paper proposes a three-part explanation for the paradoxical emergence and escalation of ...

  17. Democracy and Student Discontent: Chilean Student Protest in the Post-Pinochet Era

    OpenAIRE

    Cummings, Peter M. M.

    2015-01-01

    "Objective indicators suggest that economic and political conditions improved in Chile between the country's democratization in 1990 and 2011. Average incomes increased, poverty rates decreased, and the number of positive reviews of Chilean democratic institutions rose. Despite this progress, massive student-led protest waves in 2006 and 2011 demonstrated high levels of subjective discontent in Chile. This paper proposes a three-part explanation for the paradoxical emergence and escalation of...

  18. Democracy and Student Discontent: Chilean Student Protest in the Post-Pinochet Era

    OpenAIRE

    Cummings, Peter M. M.

    2015-01-01

    Objective indicators suggest that economic and political conditions improved in Chile between the country’s democratization in 1990 and 2011. Average incomes increased, poverty rates decreased, and the number of positive reviews of Chilean democratic institutions rose. Despite this progress, massive student-led protest waves in 2006 and 2011 demonstrated high levels of subjective discontent in Chile. This paper proposes a three-part explanation for the paradoxical emergence and escalation o...

  19. Chilean Native Fruit Extracts Inhibit Inflammation Linked to the Pathogenic Interaction Between Adipocytes and Macrophages

    OpenAIRE

    Reyes-Farias, Marjorie; Vasquez, Karla; Ovalle-Marin, Angelica; Fuentes, Francisco; Parra, Claudia; Quitral, Vilma; Jimenez, Paula; Garcia-Diaz, Diego F.

    2015-01-01

    Obesity is characterized by an increase in the infiltration of monocytes into the adipose tissue, causing an inflammatory condition associated with, for example, the development of insulin resistance. Thus, anti-inflammatory-based treatments could emerge as a novel and interesting approach. It has been reported that Chilean native fruits maqui (Aristotelia chilensis) and calafate (Berberis microphylla) present high contents of polyphenols, which are known for their antioxidant and anti-inflam...

  20. U.S. and Chilean College Students' Reading Practices: A Cross-Cultural Perspective

    Science.gov (United States)

    Huang, Suhua; Orellana, Pelusa; Capps, Matthew

    2016-01-01

    The purpose of this study was to investigate the differences between the amounts of time that U.S. and Chilean students spend on conventional academic reading, extracurricular reading, and Facebook and also to report the types of materials they prefer to read. The study surveyed students in the United States (n = 1,265) and Chile (n = 2,076)…

  1. Profiles of emotional intelligence and learning strategies in a sample of Chilean students

    OpenAIRE

    García Fernández, José Manuel; Cándido J. Inglés; Suriá Martínez, Raquel; Lagos San Martín, Nelly; Gonzálvez Macià, Carolina; Aparisi Sierra, David; Martínez Monteagudo, María C.

    2015-01-01

    In the last few years, one of the lines of research of great interest in the field of emotional intelligence (EI) has been the analysis of the role of emotions in the educational context and, in particular, their influence on learning strategies. The aims of this study are to identify the existence of different EI profiles and to determine possible statistically significant differences in learning strategies between the obtained profiles. The study involved 1253 Chilean school students from 1...

  2. Ecology of Chilean dolphins and Peale's dolphins at Isla Chiloe, southern Chile

    OpenAIRE

    Heinrich, Sonja

    2006-01-01

    Information on the ecology of sympatric species provides important insights into how different animals interact with their environment, with each other, and how they differ in their susceptibility to threats to their survival. In this study habitat use and population ecology of Chilean dolphins (Cephalorhynchus eutropia) and sympatric Peale's dolphins (Lagenorhynchus australis) were investigated in the Chiloe Archipelago in southern Chile from 2001 to 2004. Distribution data collected during ...

  3. Crustacean zooplankton species richness in Chilean lakes and ponds (23°-51°S)

    OpenAIRE

    Patricio De los Ríos-Escalante

    2013-01-01

    Chilean inland-water ecosystems are characterized by their low species-level biodiversity. This study analyses available data on surface area, maximum depth, conductivity, chlorophyll-α concentration, and zooplankton crustacean species number in lakes and ponds between 23° and 51°S. The study uses multiple regression analysis to identify the potential factors affecting the species number. The partial correlation analysis indicated a direct significant correlation between chlorophyll-α concent...

  4. Estimating enteric methane emissions from Chilean beef fattening systems using a mechanistic model

    OpenAIRE

    Arias, RA; Catrileo, A; Larraín, R; Vera, R; Velásquez, A.; Toneatti, M; France, J; Dijkstra, J.; Kebreab, E.

    2015-01-01

    Copyright © 2014 Cambridge University Press. A mechanistic model (COWPOLL) was used to estimate enteric methane (CH4) emissions from beef production systems in Chile. The results expressed as a proportion of gross energy intake (GEI) were compared with enteric fermentation data reported in the last Chilean greenhouse gases inventory, which utilized an earlier the Intergovernmental Panel on Climate Change Tier 2 approach. The simulation analysis was based on information from feedstuffs, dry ma...

  5. The Epidemiology of Sleep Quality and Consumption of Stimulant Beverages among Patagonian Chilean College Students

    OpenAIRE

    Juan Carlos Vélez; Aline Souza; Samantha Traslaviña; Clarita Barbosa; Adaeze Wosu; Asterio Andrade; Megan Frye; Annette L. Fitzpatrick; Bizu Gelaye; Williams, Michelle A.

    2013-01-01

    Objectives:. (1) To assess sleep patterns and parameters of sleep quality among Chilean college students and (2) to evaluate the extent to which stimulant beverage use and other lifestyle characteristics are associated with poor sleep quality. Methods:. A cross-sectional study was conducted among college students in Patagonia, Chile. Students were asked to complete a self-administered questionnaire to provide information about lifestyle and demographic characteristics. The Pittsburgh Sleep Qu...

  6. The dance of those left behind. Chilean high school students and the possibility of disagreement

    Directory of Open Access Journals (Sweden)

    Irene Depetris Chauvin

    2014-06-01

    Full Text Available The article examines the high school students’ protest against the neoliberal conception of education during the first period of President Michelle Bachelet government. Specifically, I analyze how the new generation of young Chileans critically uses and produces pop culture — photoblogs, posters, and stencils — in order to express disagreement with the mercantilist approach to education and the very concept of neoliberal freedom and equality.

  7. Nephelometric Dropsonde for Volcanic Ash Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Advanced dropsondes that could effectively be guided through atmospheric regions of interest such as volcanic plumes could enable unprecedented observations of...

  8. Long-lived explosive volcanism on Mercury

    OpenAIRE

    Thomas, Rebecca J.; Rothery, David A.; Conway, Susan J.; Anand, Mahesh

    2014-01-01

    The duration and timing of volcanic activity on Mercury are key indicators of the thermal evolution of the planet and provide a valuable comparative example for other terrestrial bodies. The majority of effusive volcanism on Mercury appears to have occurred early in the planet's geological history (~4.1–3.55 Ga), but there is also evidence for explosive volcanism. Here we present evidence that explosive volcanism occurred from at least 3.9 Ga until less than a billion years ago and so was sub...

  9. Catastrophic volcanic collapse: relation to hydrothermal processes.

    Science.gov (United States)

    López, D L; Williams, S N

    1993-06-18

    Catastrophic volcanic collapse, without precursory magmatic activity, is characteristic of many volcanic disasters. The extent and locations of hydrothermal discharges at Nevado del Ruiz volcano, Colombia, suggest that at many volcanoes collapse may result from the interactions between hydrothermal fluids and the volcanic edifice. Rock dissolution and hydrothermal mineral alteration, combined with physical triggers such as earth-quakes, can produce volcanic collapse. Hot spring water compositions, residence times, and flow paths through faults were used to model potential collapse at Ruiz. Caldera dimensions, deposits, and alteration mineral volumes are consistent with parameters observed at other volcanoes.

  10. Volcanic hazards and public response

    Science.gov (United States)

    Peterson, Donald W.

    1988-05-01

    Although scientific understanding of volcanoes is advancing, eruptions continue to take a substantial toll of life and property. Some of these losses could be reduced by better advance preparation, more effective flow of information between scientists and public officials, and better understanding of volcanic behavior by all segments of the public. The greatest losses generally occur at volcanoes that erupt infrequently where people are not accustomed to dealing with them. Scientists sometimes tend to feel that the blame for poor decisions in emergency management lies chiefly with officials or journalists because of their failure to understand the threat. However, the underlying problem embraces a set of more complex issues comprising three pervasive factors. The first factor is the volcano: signals given by restless volcanoes are often ambiguous and difficult to interpret, especially at long-quiescent volcanoes. The second factor is people: people confront hazardous volcanoes in widely divergent ways, and many have difficulty in dealing with the uncertainties inherent in volcanic unrest. The third factor is the scientists: volcanologists correctly place their highest priority on monitoring and hazard assessment, but they sometimes fail to explain clearly their conclusions to responsible officials and the public, which may lead to inadequate public response. Of all groups in society, volcanologists have the clearest understanding of the hazards and vagaries of volcanic activity; they thereby assume an ethical obligation to convey effectively their knowledge to benefit all of society. If society resists, their obligation nevertheless remains. They must use the same ingenuity and creativity in dealing with information for the public that they use in solving scientific problems. When this falls short, even excellent scientific results may be nullified.

  11. Thermal vesiculation during volcanic eruptions.

    Science.gov (United States)

    Lavallée, Yan; Dingwell, Donald B; Johnson, Jeffrey B; Cimarelli, Corrado; Hornby, Adrian J; Kendrick, Jackie E; von Aulock, Felix W; Kennedy, Ben M; Andrews, Benjamin J; Wadsworth, Fabian B; Rhodes, Emma; Chigna, Gustavo

    2015-12-24

    Terrestrial volcanic eruptions are the consequence of magmas ascending to the surface of the Earth. This ascent is driven by buoyancy forces, which are enhanced by bubble nucleation and growth (vesiculation) that reduce the density of magma. The development of vesicularity also greatly reduces the 'strength' of magma, a material parameter controlling fragmentation and thus the explosive potential of the liquid rock. The development of vesicularity in magmas has until now been viewed (both thermodynamically and kinetically) in terms of the pressure dependence of the solubility of water in the magma, and its role in driving gas saturation, exsolution and expansion during decompression. In contrast, the possible effects of the well documented negative temperature dependence of solubility of water in magma has largely been ignored. Recently, petrological constraints have demonstrated that considerable heating of magma may indeed be a common result of the latent heat of crystallization as well as viscous and frictional heating in areas of strain localization. Here we present field and experimental observations of magma vesiculation and fragmentation resulting from heating (rather than decompression). Textural analysis of volcanic ash from Santiaguito volcano in Guatemala reveals the presence of chemically heterogeneous filaments hosting micrometre-scale vesicles. The textures mirror those developed by disequilibrium melting induced via rapid heating during fault friction experiments, demonstrating that friction can generate sufficient heat to induce melting and vesiculation of hydrated silicic magma. Consideration of the experimentally determined temperature and pressure dependence of water solubility in magma reveals that, for many ascent paths, exsolution may be more efficiently achieved by heating than by decompression. We conclude that the thermal path experienced by magma during ascent strongly controls degassing, vesiculation, magma strength and the effusive

  12. Thermal vesiculation during volcanic eruptions

    Science.gov (United States)

    Lavallée, Yan; Dingwell, Donald B.; Johnson, Jeffrey B.; Cimarelli, Corrado; Hornby, Adrian J.; Kendrick, Jackie E.; von Aulock, Felix W.; Kennedy, Ben M.; Andrews, Benjamin J.; Wadsworth, Fabian B.; Rhodes, Emma; Chigna, Gustavo

    2015-12-01

    Terrestrial volcanic eruptions are the consequence of magmas ascending to the surface of the Earth. This ascent is driven by buoyancy forces, which are enhanced by bubble nucleation and growth (vesiculation) that reduce the density of magma. The development of vesicularity also greatly reduces the ‘strength’ of magma, a material parameter controlling fragmentation and thus the explosive potential of the liquid rock. The development of vesicularity in magmas has until now been viewed (both thermodynamically and kinetically) in terms of the pressure dependence of the solubility of water in the magma, and its role in driving gas saturation, exsolution and expansion during decompression. In contrast, the possible effects of the well documented negative temperature dependence of solubility of water in magma has largely been ignored. Recently, petrological constraints have demonstrated that considerable heating of magma may indeed be a common result of the latent heat of crystallization as well as viscous and frictional heating in areas of strain localization. Here we present field and experimental observations of magma vesiculation and fragmentation resulting from heating (rather than decompression). Textural analysis of volcanic ash from Santiaguito volcano in Guatemala reveals the presence of chemically heterogeneous filaments hosting micrometre-scale vesicles. The textures mirror those developed by disequilibrium melting induced via rapid heating during fault friction experiments, demonstrating that friction can generate sufficient heat to induce melting and vesiculation of hydrated silicic magma. Consideration of the experimentally determined temperature and pressure dependence of water solubility in magma reveals that, for many ascent paths, exsolution may be more efficiently achieved by heating than by decompression. We conclude that the thermal path experienced by magma during ascent strongly controls degassing, vesiculation, magma strength and the effusive

  13. Geomorphic assessment of late Quaternary volcanism in the Yucca Mountain area, southern Nevada: Implications for the proposed high-level radioactive waste repository

    Science.gov (United States)

    Wells, S. G.; McFadden, L. D.; Renault, C. E.; Crowe, B. M.

    1990-06-01

    Volcanic hazard studies for high-level radioactive waste isolation in the Yucca Mountain area, Nevada, require a detailed understanding of Quaternary volcanism to forecast rates of volcanic processes. Recent studies of the Quaternary Cima volcanic field in southern California have demonstrated that K-Ar dates of volcanic landforms are consistent with their geomorphic and pedologic properties. The systematic change of these properties with time may be used to provide age estimates of undated or questionably dated volcanic features. The reliability off radiometric age determinations of the youngest volcanic center, Lathrop Wells, near the proposed Yucca Mountain site in Nevada has been problematic. In this study, a comparison of morphometric, pedogenic, and stratigraphic data establishes that correlation of geomorphic and soil properties between the Cima volcanic field and the Yucca Mountain area is valid. Comparison of the Lathrop Wells cinder cone to a 15-20 ka cinder cone in California shows that their geomorphic-pedogenic properties are similar and implies that the two cones are of similar age. We conclude that previous determinations of ca. 0.27 Ma for the latest volcanic activity at Lathrop Wells, approximately 20 km from the proposed repository, may be in error by as much as an order of magnitude and that the most recent volcanic activity is no older than 20 ka.

  14. Content validity and reliability of test of gross motor development in Chilean children

    Directory of Open Access Journals (Sweden)

    Marcelo Cano-Cappellacci

    2015-01-01

    Full Text Available ABSTRACT OBJECTIVE To validate a Spanish version of the Test of Gross Motor Development (TGMD-2 for the Chilean population. METHODS Descriptive, transversal, non-experimental validity and reliability study. Four translators, three experts and 92 Chilean children, from five to 10 years, students from a primary school in Santiago, Chile, have participated. The Committee of Experts has carried out translation, back-translation and revision processes to determine the translinguistic equivalence and content validity of the test, using the content validity index in 2013. In addition, a pilot implementation was achieved to determine test reliability in Spanish, by using the intraclass correlation coefficient and Bland-Altman method. We evaluated whether the results presented significant differences by replacing the bat with a racket, using T-test. RESULTS We obtained a content validity index higher than 0.80 for language clarity and relevance of the TGMD-2 for children. There were significant differences in the object control subtest when comparing the results with bat and racket. The intraclass correlation coefficient for reliability inter-rater, intra-rater and test-retest reliability was greater than 0.80 in all cases. CONCLUSIONS The TGMD-2 has appropriate content validity to be applied in the Chilean population. The reliability of this test is within the appropriate parameters and its use could be recommended in this population after the establishment of normative data, setting a further precedent for the validation in other Latin American countries.

  15. [Position paper from the Department of Ethics of the Chilean College of Physicians about conscientious objection].

    Science.gov (United States)

    Salas, Sofía P; Besio, Mauricio; Bórquez Estefó, Gladys; Salinas, Rodrigo A; Valenzuela, Carlos Y; Micolich, Constanza; Novoa Sotta, Fernando; Bernier Villarroel, Lioniel; Montt M, Julio; Misseroni Raddatz, Adelio

    2016-03-01

    The Chilean bill that regulates abortion for three cases (Bulletin Nº 9895-11) includes the possibility that health professionals may manifest their conscientious objection (CO) to perform this procedure. Due to the broad impact that the issue of C O had, the Ethics Department of the Chilean College of Physicians considered important to review this concept and its ethical and legal basis, especially in the field of sexual and reproductive health. In the present document, we define the practical limit s of CO, both for the proper fulfillment of the medical profession obligations, and for the due respect and non-discrimination that the professional objector deserves. We analyze the denial of some health institutions to perform abortions if it is legalize d, and we end with recommendations adjusted to the Chilean reality. Specifically, we recognize the right to conscientious objection that all physicians who directly participate in a professional act have. But we a lso recognize that physicians have ineludib le obligations towards their patients, including the obligation to inform about the existence of this service, how to access to it and -as set out in our code of ethics- to ensure that another colleague will continue attending the patient. PMID:27299826

  16. ICT in Chilean Schools: Students' and Teachers' Access and Use of ICT

    Directory of Open Access Journals (Sweden)

    J. Enrique Hinostroza

    2005-01-01

    Full Text Available This paper presents the results of the analysis of the data from a national survey of the Chilean educational ICT infrastructure and its use in schools implemented by the Centre for Technology and Education of the Chilean Ministry of Education in 2004. Results show that the context of ICT use in Chilean schools can be characterized as relatively good, insofar as there are no first-order barriers for implementing ICT pedagogy. In this context, students’ ICT use can be categorized based on four factors: communication, productivity, recreation, and communication with teachers. On the other hand, teachers’ ICT use can be categorized using three factors: communication, teaching, and technical. Based on these factors and considering the availability and use of ICT in schools, the question remains how to make this time most effective for improving students’ learning. Additionally, results show that students, on their own, spend a considerable amount of time developing activities described as communication. The question that arises from this finding is how to take advantage of these activities in order to meet teaching and learning aims. Regarding teachers, results open possibilities for redesigning professional development courses by taking advantage of what they already do with ICT.

  17. Polyunsaturated Fatty Acid Composition of Maternal Diet and Erythrocyte Phospholipid Status in Chilean Pregnant Women

    Directory of Open Access Journals (Sweden)

    Karla A. Bascuñán

    2014-11-01

    Full Text Available Chilean diets are characterized by a low supply of n-3 polyunsaturated fatty acids (n-3 PUFA, which are critical nutrients during pregnancy and lactation, because of their role in brain and visual development. DHA is the most relevant n-3 PUFA in this period. We evaluated the dietary n-3 PUFA intake and erythrocyte phospholipids n-3 PUFA in Chilean pregnant women. Eighty healthy pregnant women (20–36 years old in the 3rd–6th month of pregnancy were included in the study. Dietary assessment was done applying a food frequency questionnaire, and data were analyzed through the Food Processor SQL® software. Fatty acids of erythrocyte phospholipids were assessed by gas-liquid chromatography. Diet composition was high in saturated fat, low in mono- and PUFA, high in n-6 PUFA (linoleic acid and low in n-3 PUFA (alpha-linolenic acid and DHA, with imbalance in the n-6/n-3 PUFA ratio. Similar results were observed for fatty acids from erythrocyte phospholipids. The sample of Chilean pregnant women showed high consumption of saturated fat and low consumption of n-3 PUFA, which is reflected in the low DHA content of erythrocyte phospholipids. Imbalance between n-6/n-3 PUFA could negatively affect fetal development. New strategies are necessary to improve n-3 PUFA intake throughout pregnancy and breast feeding periods. Furthermore, it is necessary to develop dietary interventions to improve the quality of consumed foods with particular emphasis on n-3 PUFA.

  18. SOCIAL POLICY AGENDAS AND CONSTRUCTION OF DEMOCRACY IN THE CHILEAN TRANSITION PROCESS

    Directory of Open Access Journals (Sweden)

    Gonzalo Delamaza

    2012-12-01

    Full Text Available Social policies have been the greatest field of innovation in Chilean state action since 1990. These policies were conceived as a key factor to ensure governance in the political transition to democracy, to strengthen the economic model and to re-establish a link between State and society. This article examines some governmental political initiatives in different areas of social policy. It is important to know how these social programs and policies have shaped the relationship between the new State, which emerged from the negotiations in the late 1980s, and the Chilean society. For this purpose, the general approaches which underlie this policy are reviewed, and then the orientations within them are differentiated. There are five different patterns or tendencies in Chilean social policy, according to their orientation, institutional management and type of relationship with the social organizations. Two of them arose as a result of the implementation of innovative approaches during the 1990s, which also led to the creation of new agencies. A third one is related with the reorientation of policies in traditional areas. The last two of the analyzed trends refer to the interfaces between the social policy and civil society at the local sphere (decentralized entities and externalization - or outsourcing - of the relationship.

  19. Strategic Evolution of Chilean Wine Firms: Vertical Integration and Upgrading in Chile’s Colchagua Valley

    Directory of Open Access Journals (Sweden)

    Robert N. Gwynne

    2012-01-01

    Full Text Available This paper argues that the favourable export trajectories for Chilean wine to global markets in general and the UK market in particular are partly due to the nature of the insertion of wine producing firms into global value chains. Much of the data in this paper comes from a two-year British Academy research project (2005-07 which examined the impacts of globalization on export-oriented wine firms in Chile’s Colchagua Valley and the record of collaboration between these firms and key purchasing companies within the UK market. The paper examines the political economy of value chains in agro-industry, retail concentration in core economy markets and the relevance of convention theory to value chains in the wine sector. The paper then analyses how value chains give context to the nature of upgrading within the Chilean wine sector by focusing on: the strategic example of the lead firm; firm upgrading as a response to the demands of and knowledge flows from retailers; and firm upgrading through the flying winemaker model. The paper will conclude by assessing the relevance of the Chilean experience for other countries wishing to rapidly expand their wine exports, such as those in S. E. Europe.

  20. Democracy and Student Discontent: Chilean Student Protest in the Post-Pinochet Era

    Directory of Open Access Journals (Sweden)

    Peter M. M. Cummings

    2015-01-01

    Full Text Available Objective indicators suggest that economic and political conditions improved in Chile between the country’s democratization in 1990 and 2011. Average incomes increased, poverty rates decreased, and the number of positive reviews of Chilean democratic institutions rose. Despite this progress, massive student-led protest waves in 2006 and 2011 demonstrated high levels of subjective discontent in Chile. This paper proposes a three-part explanation for the paradoxical emergence and escalation of the post-Pinochet-era Chilean student protests, and, in so doing, contributes to the broader understanding of social movements and political action. The first two parts of the argument relate to generational change. Firstly, a gap between expectations and capabilities provoked discontent amongst a new generation of Chilean students. Secondly, the new generation’s collective identity as “la generación sin miedo” (the fearless generation motivated the students to turn discontent into political action. Thirdly, government and student actor agency influenced the variance in protest strength between 2005 and 2011.

  1. Water in volcanic glass: From volcanic degassing to secondary hydration

    Science.gov (United States)

    Seligman, Angela N.; Bindeman, Ilya N.; Watkins, James M.; Ross, Abigail M.

    2016-10-01

    Volcanic glass is deposited with trace amounts (0.1-0.6 wt.%) of undegassed magmatic water dissolved in the glass. After deposition, meteoric water penetrates into the glass structure mostly as molecular H2O. Due to the lower δD (‰) values of non-tropical meteoric waters and the ∼30‰ offset between volcanic glass and environmental water during hydration, secondary water imparts lighter hydrogen isotopic values during secondary hydration up to a saturation concentration of 3-4 wt.% H2O. We analyzed compositionally and globally diverse volcanic glass from 0 to 10 ka for their δD and H2Ot across different climatic zones, and thus different δD of precipitation, on a thermal conversion elemental analyzer (TCEA) furnace attached to a mass spectrometer. We find that tephrachronologically coeval rhyolite glass is hydrated faster than basaltic glass, and in the majority of glasses an increase in age and total water content leads to a decrease in δD (‰), while a few equatorial glasses have little change in δD (‰). We compute a magmatic water correction based on our non-hydrated glasses, and calculate an average 103lnαglass-water for our hydrated felsic glasses of -33‰, which is similar to the 103lnαglass-water determined by Friedman et al. (1993a) of -34‰. We also determine a smaller average 103lnαglass-water for all our mafic glasses of -23‰. We compare the δD values of water extracted from our glasses to local meteoric waters following the inclusion of a -33‰ 103lnαglass-water. We find that, following a correction for residual magmatic water based on an average δD and wt.% H2Ot of recently erupted ashes from our study, the δD value of water extracted from hydrated volcanic glass is, on average, within 4‰ of local meteoric water. To better understand the difference in hydration rates of mafic and felsic glasses, we imaged 6 tephra clasts ranging in age and chemical composition with BSE (by FEI SEM) down to a submicron resolution. Mafic tephra

  2. Geochemical Characteristics and Metallogenesis of Volcanic Rocks as Exemplified by Volcanic Rocks in Ertix,Xinjiang

    Institute of Scientific and Technical Information of China (English)

    刘铁庚; 叶霖

    1997-01-01

    Volcanic rocks in Ertix,Xinjiang,occurring in the collision zone between the Siberia Plate and the Junggar Plate,are distributed along the Eritix River Valley in northern Xinjiang.The volcanic rocks were dated at Late Paleozoic and can be divided into the spilite-keratophyre series and the basalt-andesite series.The spilite-keratophyre series volcanic rocks occur in the Altay orogenic belt at the southwest margin of the Siberia Plate.In addition to sodic volcanic rocks.There are also associated potassic-sodic volcanic rocks and potassic volcanic rocks.The potassic-sodic volcanic rocks occur at the bottom of the eruption cycle and control the distribution of Pb and Zn deposits.The potassic volcanic rocks occur at the top of the eruption cycle and are associated with Au and Cu mineralizations.The sodic volcanic rocks occur in the middle stage of eruption cycle and control the occurrence of Cu(Zn) deposits.The basalt-andesite series volcanic rocks distributed in the North Junggar orogenic belt at the north margin of the Junggar-Kazakstan Plate belong to the potassic sodic volcain rocks.The volcanic rocks distributed along the Ulungur fault are relatively rich in sodium and poor in potassium and are predominated by Cu mineralization and associated with Au mineralization.Those volcanic rocks distributed along the Ertix fault are relatively rich in K and poor in Na,with Au mineralization being dominant.

  3. Soil radon response around an active volcano

    Energy Technology Data Exchange (ETDEWEB)

    Segovia, N. E-mail: msa@nuclear.inin.mx; Valdes, C.; Pena, P.; Mena, M.; Tamez, E

    2001-06-01

    Soil radon behavior related to the volcanic eruptive period 1997-1999 of Popocatepetl volcano has been studied as a function of the volcanic activity. Since the volcano is located 60 km from Mexico City, the risk associated with an explosive eruptive phase is high and an intense surveillance program has been implemented. Previous studies in this particular volcano showed soil radon pulses preceding the initial phase of the eruption. The radon survey was performed with LR-115 track detectors at a shallow depth and the effect of the soil moisture during the rainy season has been observed on the detectors response. In the present state of the volcanic activity the soil radon behavior has shown more stability than in previous eruptive stages.

  4. Mercury-mediated cross-resistance to tellurite in Pseudomonas spp. isolated from the Chilean Antarctic territory.

    Science.gov (United States)

    Rodríguez-Rojas, F; Díaz-Vásquez, W; Undabarrena, A; Muñoz-Díaz, P; Arenas, F; Vásquez, C

    2016-01-01

    Mercury salts and tellurite are among the most toxic compounds for microorganisms on Earth. Bacterial mercury resistance is established mainly via mercury reduction by the mer operon system. However, specific mechanisms underlying tellurite resistance are unknown to date. To identify new mechanisms for tellurite detoxification we demonstrate that mercury resistance mechanisms can trigger cross-protection against tellurite to a group of Pseudomonads isolated from the Chilean Antarctic territory. Sequencing of 16S rRNA of four isolated strains resulted in the identification of three Pseudomonads (ATH-5, ATH-41 and ATH-43) and a Psychrobacter (ATH-62) bacteria species. Phylogenetic analysis showed that ATH strains were related to other species previously isolated from cold aquatic and soil environments. Furthermore, the identified merA genes were related to merA sequences belonging to transposons commonly found in isolated bacteria from mercury contaminated sites. Pseudomonas ATH isolates exhibited increased tellurite resistance only in the presence of mercury, especially ATH-43. Determination of the growth curves, minimal inhibitory concentrations and growth inhibition zones showed different tellurite cross-resistance of the ATH strains and suggested a correlation with the presence of a mer operon. On the other hand, reactive oxygen species levels decreased while the thiol content increased when the isolates were grown in the presence of both toxicants. Finally, qPCR determinations of merA, merC and rpoS transcripts from ATH-43 showed a synergic expression pattern upon combined tellurite and mercury treatments. Altogether, the results suggest that mercury could trigger a cell response that confers mercury and tellurite resistance, and that the underlying mechanism participates in protection against oxidative damage.

  5. GOSAT/TANSO-FTS Measurement of Volcanic and Geothermal CO2 Emissions

    Science.gov (United States)

    Schwandner, Florian M.; Carn, Simon A.; Newhall, Christopher G.

    2010-05-01

    Approximately one tenth of the Earth's human population lives in direct reach of volcanic hazards. Being able to provide sufficiently early and scientifically sound warning is a key to volcanic hazard mitigation. Quantitative time-series monitoring of volcanic CO2 emissions will likely play a key role in such early warning activities in the future. Impending volcanic eruptions or any potentially disastrous activity that involves movement of magma in the subsurface, is often preceded by an early increase of CO2 emissions. Conventionally, volcanic CO2 monitoring is done either in campaigns of soil emission measurements (grid of one-time measuring points) that are labor intensive and slow, or by ground-based remote FTIR measurements in emission plumes. These methods are not easily available at all sites of potential activity and prohibitively costly to employ on a large number of volcanoes. In addition, both of these ground-based approaches pose a significant risk to the workers conducting these measurements. Some aircraft-based measurements have been conducted as well in the past, however these are limited by the usually meager funding situation of individual observatories, the hazard such flights pose to equipment and crew, and by the inaccessibility of parts of the plume due to ash hazards. The core motivation for this study is therefore to develop a method for volcanic CO2 monitoring from space that will provide sufficient coverage, resolution, and data quality for an application to quantitative time series monitoring and correlation with other available datasets, from a safe distance and with potentially global reach. In summary, the purpose of the proposed research is to quantify volcanic CO2 emissions using satellite-borne observations. Quantitative estimates will be useful for warning of impending volcanic eruptions, and assessing the contribution of volcanic CO2 to global GHG. Our approach encompasses method development and testing for the detection of

  6. Automatic semi-continuous accumulation chamber for diffuse gas emissions monitoring in volcanic and non-volcanic areas

    Science.gov (United States)

    Lelli, Matteo; Raco, Brunella; Norelli, Francesco; Virgili, Giorgio; Continanza, Davide

    2016-04-01

    Since various decades the accumulation chamber method is intensively used in monitoring activities of diffuse gas emissions in volcanic areas. Although some improvements have been performed in terms of sensitivity and reproducibility of the detectors, the equipment used for measurement of gas emissions temporal variation usually requires expensive and bulky equipment. The unit described in this work is a low cost, easy to install-and-manage instrument that will make possible the creation of low-cost monitoring networks. The Non-Dispersive Infrared detector used has a concentration range of 0-5% CO2, but the substitution with other detector (range 0-5000 ppm) is possible and very easy. Power supply unit has a 12V, 7Ah battery, which is recharged by a 35W solar panel (equipped with charge regulator). The control unit contains a custom programmed CPU and the remote transmission is assured by a GPRS modem. The chamber is activated by DataLogger unit, using a linear actuator between the closed position (sampling) and closed position (idle). A probe for the measure of soil temperature, soil electrical conductivity, soil volumetric water content, air pressure and air temperature is assembled on the device, which is already arranged for the connection of others external sensors, including an automatic weather station. The automatic station has been tested on the field at Lipari island (Sicily, Italy) during a period of three months, performing CO2 flux measurement (and also weather parameters), each 1 hour. The possibility to measure in semi-continuous mode, and at the same time, the gas fluxes from soil and many external parameters, helps the time series analysis aimed to the identification of gas flux anomalies due to variations in deep system (e.g. onset of volcanic crises) from those triggered by external conditions.

  7. Cenozoic volcanic rocks of Saudi Arabia

    Science.gov (United States)

    Coleman, R.G.; Gregory, R.T.; Brown, G.F.

    2016-01-01

    The Cenozoic volcanic rocks of Saudi Arabia cover about 90,000 km2, one of the largest areas of alkali olivine basalt in the world. These volcanic rocks are in 13 separate fields near the eastern coast of the Red Sea and in the western Arabian Peninsula highlands from Syria southward to the Yemen Arab Republic.

  8. Availability of Nitrogen, Phosphorus and Potassium from Poultry Litter and Conventional Fertilizers in a Volcanic Soil Cultivated with Silage Corn Disponibilidad de Nitrógeno, Fósforo y Potasio de Cama de Broiler y Fertilizantes Convencionales en un Suelo Volcánico Cultivado con Maíz

    Directory of Open Access Journals (Sweden)

    Juan Hirzel

    2008-09-01

    Full Text Available Poultry litter (PL is an organic matter source used as soil amendment. Besides its important nutrient content, it is a cheap alternative to conventional fertilizers in crop production. The efficient use of PL also helps reduce the environmental problems normally associated with its disposal near poultry production farms. This article reports the relative effects of PL and conventional fertilizers on the availability of soil N, P and K, dry matter (DM production and total nutrient content in silage corn (Zea mays L.. The field experiment was carried out in a soil derived from volcanic ash (Tipic Melanoxerands of Central South Chile. Corn was grown for three seasons (2002-2005 and PL and conventional fertilizers were applied in the first two years. The residual effect of the added fertilizer sources was evaluated in the third year. DM production in the fertilized treatments was similar and fluctuated between 30.6 and 37.1 Mg ha-1 for the two years of fertilization, and between 18.9 and 20.4 Mg ha-1 for the year without addition of nutrients. The plant nutrient concentrations were similar between fertilized treatments, except for the second year, in which N and P concentrations were higher with PL. During the third year (without fertilization, N decreased in the whole plant. Soil nutrient availability was similar between fertilization sources for the three years evaluated, the higher concentration being presented in the first two years (with fertilization. These results suggest that PL is an alternative fertilizer source to conventional fertilizers.La cama de broiler (PL es un compuesto orgánico utilizado como enmienda de suelos, cuyo contenido de nutrientes y bajo precio permiten considerarla como una alternativa al uso de fertilizantes. El uso de PL como fertilizante permite disminuir el riesgo de contaminación ambiental en las zonas de acopio. En este trabajo se compara el efecto en producción de materia seca (MS y concentración de

  9. Relationship between earthquake and volcanic eruption inferred from historical records

    Institute of Scientific and Technical Information of China (English)

    陈洪洲; 高峰; 吴雪娟; 孟宪森

    2004-01-01

    A large number of seismic records are discovered for the first time in the historical materials about Wudalianchi volcanic group eruption in 1720~1721, which provides us with abundant volcanic earthquake information. Based on the written records, the relationship between earthquake and volcanic eruption is discussed in the paper. Furthermore it is pointed that earthquake swarm is an important indication of volcanic eruption. Therefore, monitoring volcanic earthquakes is of great significance for forecasting volcanic eruption.

  10. Adverse childhood experiences, mental health, and quality of life of Chilean girls placed in foster care: An exploratory study.

    Science.gov (United States)

    Seiler, Annina; Kohler, Stefanie; Ruf-Leuschner, Martina; Landolt, Markus A

    2016-03-01

    In Latin America, little research has been conducted regarding exposure to adverse childhood experiences (ACEs), mental health, and health-related quality of life (HRQoL) among foster children. This study examined the association between ACEs and mental health, posttraumatic stress disorder (PTSD), and HRQoL in Chilean foster girls relative to age-matched Chilean family girls. Data were obtained from 27 Chilean foster girls and 27 Chilean girls ages 6 to 17 years living in family homes. Standardized self- and proxy-report measures were used. Foster girls reported more ACEs than controls in terms of familial and nonfamilial sexual abuse and both emotional and physical neglect. Girls living in foster care had a significantly higher rate of PTSD, displayed greater behavioral and emotional problems, and reported a lower HRQoL. Analysis confirmed the well-known cumulative risk hypothesis by demonstrating a significant positive association between the number of ACEs and PTSD symptom severity and a significant negative association with HRQoL. Chilean foster girls endured more ACEs that impair mental health and HRQoL than age-matched peers living with their families. These findings have implications for out-of-home care services in Latin America, highlighting the need to implement not only appropriate trauma-focused treatments but also appropriate prevention strategies. PMID:25915644

  11. Hydrogeology of the Azores volcanic archipelago (Portugal)

    Science.gov (United States)

    Cruz, J.; Coutinho, R.; Antunes, P.; Freire, P.

    2009-04-01

    The archipelago of the Azores is made of nine islands of volcanic origin located in the North Atlantic Ocean, with an area of 2333 km2 and approximately 237500 inhabitants, which are 98% dependant from groundwater sources for their water consumption. Therefore, groundwater is a resource that plays a vital role as drinking water source and as ecosystem support matrix. Nevertheless, besides the environmental, social and economical value of groundwater, this resource is subject to an increase pressure and in several islands water quality deterioration is shown by monitoring data. This pressure is also shown by the 42.7% increase expected for domestic use until the year 2020 at the Azores, with higher groundwater abstraction. The Azores climate can be considered as marine temperate, which is reflected by the low thermal amplitude and high precipitation. A well-established difference between a dry season and a colder and wet season occurs, as from October to March about 75% of the annual precipitation is registered. The average annual precipitation at the Azores is 1930 mm, exceeding by far the average annual actual evapotranspiration, which is 581 mm. Recharge rates range from 8.5% to 62.1%, and the highest values are observed at Pico, Terceira, Faial, São Miguel and Graciosa islands, especially in areas where the terrain is covered by recent basaltic lava flows and the soil cover is sparse. Groundwater resources estimates point to a total volume of about 1600x106 m3/yr. Values above the recharge median, equal to 101.3x106 m3/yr. were estimated for the São Miguel, São Jorge, Terceira and Flores islands. Despite differences in the islands growth, as a result of successive volcanic eruptions of various types, groundwater occurrence can be described in function of two main aquifers systems: (1) the basal aquifer system, which corresponds to fresh-water lenses floating on underlying salt water, and (2) perched-water bodies, which are usually drained by springs spread in

  12. Assessing volcanic hazards with Vhub

    Science.gov (United States)

    Palma, J. L.; Charbonnier, S.; Courtland, L.; Valentine, G.; Connor, C.; Connor, L.

    2012-04-01

    Vhub (online at vhub.org) is a virtual organization and community cyberinfrastructure designed for collaboration in volcanology research, education, and outreach. One of the core objectives of this project is to accelerate the transfer of research tools to organizations and stakeholders charged with volcano hazard and risk mitigation (such as volcano observatories). Vhub offers a clearinghouse for computational models of volcanic processes and data analysis, documentation of those models, and capabilities for online collaborative groups focused on issues such as code development, configuration management, benchmarking, and validation. Vhub supports computer simulations and numerical modeling at two levels: (1) some models can be executed online via Vhub, without needing to download code and compile on the user's local machine; (2) other models are not available for online execution but for offline use in the user's computer. VHub also has wikis, blogs and group functions around specific topics to encourage collaboration, communication and discussion. Some of the simulation tools currently available to Vhub users are: Energy Cone (rapid delineation of the impact zone by pyroclastic density currents), Tephra2 (tephra dispersion forecast tool), Bent (atmospheric plume analysis), Hazmap (simulate sedimentation of volcanic particles) and TITAN2D (mass flow simulation tool). The list of online simulations available on Vhub is expected to expand considerably as the volcanological community becomes more involved in the project. This presentation focuses on the implementation of online simulation tools, and other Vhub's features, for assessing volcanic hazards following approaches similar to those reported in the literature. Attention is drawn to the minimum computational resources needed by the user to carry out such analyses, and to the tools and media provided to facilitate the effective use of Vhub's infrastructure for hazard and risk assessment. Currently the project

  13. Geomorphological Approach for Regional Zoning In The Merapi Volcanic Area

    Directory of Open Access Journals (Sweden)

    Langgeng Wahyu Santosa

    2013-07-01

    Full Text Available Geomorphologial approach can be used as the basic for identifying and analyzing the natural resources potentials, especially in volcanic landscape. Based on its geomorphology, Merapi volcanic landscape can be divided into 5 morphological units, i.e.: volcanic cone, volcanic slope, volcanic foot, volcanic foot plain, and fluvio-volcanic plain. Each of these morphological units has specific characteristic and natural resources potential. Based on the condition of geomorphology, the regional zoning can be compiled to support the land use planning and to maintain the conservation of environmental function in the Merapi Volcanic area.

  14. Free Education! A "Live" Report on the Chilean Student Movement 2011-2014--Reform or Revolution? [A Political Sociology for Action

    Science.gov (United States)

    Simbuerger, Elisabeth; Neary, Mike

    2015-01-01

    This paper provides a report on the Chilean student movement, 2011-2014, from the perspective of the students themselves, based on the main research question: are the student protests for reform or revolution? The research data was collected during October 2013 before the Chilean Presidential and Parliamentary elections using the methodology of…

  15. The Image of E-Learning: Perceptions about a Chilean University and the E-Learning System in the Context of Chile

    Science.gov (United States)

    Farcas, Daniel

    2010-01-01

    The purpose of this research is to determine the image of a Chilean university, as perceived by those inside and outside of the institution, in contrast with the general image of the e-learning system in Chile. The internal perceptions are those of current students and graduates of this Chilean university, while the external perceptions are those…

  16. A preliminary evaluation of ERTS-1 images on the volcanic areas of Southern Italy

    Science.gov (United States)

    Cassinis, R.; Lechi, G. M.

    1973-01-01

    The test site selected for the investigation covers nearly all the regions of active and quiescent volcanism in southern Italy, i.e. the eastern part of the island of Sicily, the Aeolian Islands and the area of Naples. The three active European volcanoes (Etna, Stromboli and Vesuvius) are included. The investigation is in the frame of a program for the surveillance of active volcanoes by geophysical (including remote sensing thermal methods) and geochemical methods. By the multispectral analysis of ERTS-1 data it is intended to study the spectral behavior of the volcanic materials as well as the major geological lineaments with special reference to those associated with the volcanic region. Secondary objectives are also the determination of the hydrographic network seasonal behavior and the relationship between the vegetation cover and the different type of soils and rocks.

  17. Climatic Impact of Volcanic Eruptions

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    Gregory A. Zielinski

    2002-01-01

    Full Text Available Volcanic eruptions have the potential to force global climate, provided they are explosive enough to emit at least 1–5 megaton of sulfur gases into the stratosphere. The sulfuric acid produced during oxidation of these gases will both absorb and reflect incoming solar radiation, thus warming the stratosphere and cooling the Earth’s surface. Maximum global cooling on the order of 0.2–0.3°C, using instrumental temperature records, occurs in the first 2 years after the eruption, with lesser cooling possibly up to the 4th year. Equatorial eruptions are able to affect global climate, whereas mid- to high-latitude events will impact the hemisphere of origin. However, regional responses may differ, including the possibility of winter warming following certain eruptions. Also, El Niño warming may override the cooling induced by volcanic activity. Evaluation of different style eruptions as well as of multiple eruptions closely spaced in time beyond the instrumental record is attained through the analysis of ice-core, tree-ring, and geologic records. Using these data in conjunction with climate proxy data indicates that multiple eruptions may force climate on decadal time scales, as appears to have occurred during the Little Ice Age (i.e., roughly AD 1400s–1800s. The Toba mega-eruption of ~75,000 years ago may have injected extremely large amounts of material into the stratosphere that remained aloft for up to about 7 years. This scenario could lead to the initiation of feedback mechanisms within the climate system, such as cooling of sea-surface temperatures. These interacting mechanisms following a mega-eruption may cool climate on centennial time scales.

  18. Sulfate, chloride and fluoride retention in Andosols exposed to volcanic acid emissions.

    Science.gov (United States)

    Delmelle, Pierre; Delfosse, Thomas; Delvaux, Bruno

    2003-01-01

    The continuous emissions of SO(2), HCl and HF by Masaya volcano, Nicaragua, represent a substantial source of atmospheric S-, Cl- and F-containing acid inputs for local ecosystems. We report on the effects of such acid depositions on the sulfate, chloride and fluoride contents in soils (0-40 cm) from two distinct transects located downwind from the volcano. The first transect corresponds to relatively undifferentiated Vitric Andosols, and the second transect to more weathered Eutric Andosols. These soils are exposed to various rates of volcanogenic acid addition, with the Vitric sites being generally more affected. Prolonged acid inputs have led to a general pH decrease and reduced exchangeable base cation concentrations in the Andosols. The concentrations of 0.5 M NH(4)F- and 0.016 M KH(2)PO(4)-extractable sulfate (NH(4)F-S and KH(2)PO(4)-S, respectively) indicate that volcanic S addition has increased the inorganic sulfate content of the Vitric and Eutric soils at all depths. In this process, the rate of sulfate accumulation is also dependent on soil allophane contents. For all soils, NH(4)F extracted systematically more (up to 40 times) sulfate than KH(2)PO(4). This difference suggests sulfate incorporation into an aluminum hydroxy sulfate phase, whose contribution to total inorganic sulfate in the Vitric and Eutric Andosols is estimated from approximately 34 to 95% and approximately 65 to 98%, respectively. The distribution of KH(2)PO(4)-extractable chloride in the Vitric and Eutric Andosols exposed to volcanic Cl inputs reveals that added chloride readily migrates through the soil profiles. In contrast, reaction of fluoride with Al and Fe oxyhydroxides and allophanes is an important sink mechanism in the Masaya Andosols exposed to airborne volcanic F. Fluoride dominates the anion distribution in all soil horizons, although F is the least concentrated element in the volcanic emissions and depositions. The soil anion distribution reflects preferential retention

  19. Nitrogen Mineralization and Released Nutrients in a Volcanic Soil Amended with Poultry Litter Mineralización de Nitrógeno y Liberación de Nutrientes en un Suelo Volcánico Enmendado con Cama de Broiler

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    Juan Hirzel

    2010-03-01

    Full Text Available Optimum application rates of poultry litter (PL spread out on the farmer´s field is a valuable source of available plant nutrients. The aim of this study was to compare the effect of two rates of PL and conventional fertilization (CF on N mineralization and P, K, Zn, and Cu availability in an Andisol from Southern Chile under controlled conditions. Aerobic incubation was carried out for a 16-wk period. N mineralization rates were higher (61.5% with the two PL treatments than with conventional fertilizer (23%. CF was associated with high N availability prior to the start of incubation and slight immobilization during the first week, perhaps due to a more rapid conversion of urea into NH4 which was then temporarily immobilized by the microbial biomass. At the start and end of the incubation period, Olsen-extractable P content was generally higher in CF. Due to the high fixation capacity of the soil studied, extractable P values were slightly increased suggesting that PL mineralization is only associated with a low risk of P contamination in volcanic soil. In PL, K, Zn, and Cu availability were higher than in CF. However, values obtained for Cu and Zn were average in relation to referential values used in agricultural soil. The results indicated that PL could be an alternative to conventional fertilizer under the conditions of the present study.En sistemas agrícolas que utilizan dosis correctas de insumos, la cama de broiler (CB puede constituir una fuente económica de nutrientes para las plantas. El objetivo de este trabajo fue estudiar el efecto de CB en dos dosis y fertilización convencional (FC sobre la mineralización de N y la disponibilidad de P, K, Zn y Cu en un suelo volcánico de la zona centro-sur de Chile en condiciones controladas. Una incubación aeróbica fue realizada durante un período de 16 semanas. Las tasas de mineralización de N fueron mayores con los tratamientos de CB utilizados (61,5% respecto al uso de FC (23%. La FC

  20. Forecasting volcanic ash dispersal and coeval resuspension during the April-May 2015 Calbuco eruption

    Science.gov (United States)

    Reckziegel, F.; Bustos, E.; Mingari, L.; Báez, W.; Villarosa, G.; Folch, A.; Collini, E.; Viramonte, J.; Romero, J.; Osores, S.

    2016-07-01

    Atmospheric dispersion of volcanic ash from explosive eruptions or from subsequent fallout deposit resuspension causes a range of impacts and disruptions on human activities and ecosystems. The April-May 2015 Calbuco eruption in Chile involved eruption and resuspension activities. We overview the chronology, effects, and products resulting from these events, in order to validate an operational forecast strategy for tephra dispersal. The modelling strategy builds on coupling the meteorological Weather Research and Forecasting (WRF/ARW) model with the FALL3D dispersal model for eruptive and resuspension processes. The eruption modelling considers two distinct particle granulometries, a preliminary first guess distribution used operationally when no field data was available yet, and a refined distribution based on field measurements. Volcanological inputs were inferred from eruption reports and results from an Argentina-Chilean ash sample data network, which performed in-situ sampling during the eruption. In order to validate the modelling strategy, results were compared with satellite retrievals and ground deposit measurements. Results indicate that the WRF-FALL3D modelling system can provide reasonable forecasts in both eruption and resuspension modes, particularly when the adjusted granulometry is considered. The study also highlights the importance of having dedicated datasets of active volcanoes furnishing first-guess model inputs during the early stages of an eruption.

  1. MISR Observations of Etna Volcanic Plumes

    Science.gov (United States)

    Scollo, S.; Kahn, R. A.; Nelson, D. L.; Coltelli, M.; Diner, D. J.; Garay, M. J.; Realmuto, V. J.

    2012-01-01

    In the last twelve years, Mt. Etna, located in eastern Sicily, has produced a great number of explosive eruptions. Volcanic plumes have risen to several km above sea level and created problems for aviation and the communities living near the volcano. A reduction of hazards may be accomplished using remote sensing techniques to evaluate important features of volcanic plumes. Since 2000, the Multiangle Imaging SpectroRadiometer (MISR) on board NASA s Terra spacecraft has been extensively used to study aerosol dispersal and to extract the three-dimensional structure of plumes coming from anthropogenic or natural sources, including volcanoes. In the present work, MISR data from several explosive events occurring at Etna are analyzed using a program named MINX (MISR INteractive eXplorer). MINX uses stereo matching techniques to evaluate the height of the volcanic aerosol with a precision of a few hundred meters, and extracts aerosol properties from the MISR Standard products. We analyzed twenty volcanic plumes produced during the 2000, 2001, 2002-03, 2006 and 2008 Etna eruptions, finding that volcanic aerosol dispersal and column height obtained by this analysis is in good agreement with ground-based observations. MISR aerosol type retrievals: (1) clearly distinguish volcanic plumes that are sulphate and/or water vapor dominated from ash-dominated ones; (2) detect even low concentrations of volcanic ash in the atmosphere; (3) demonstrate that sulphate and/or water vapor dominated plumes consist of smaller-sized particles compared to ash plumes. This work highlights the potential of MISR to detect important volcanic plume characteristics that can be used to constrain the eruption source parameters in volcanic ash dispersion models. Further, the possibility of discriminating sulphate and/or water vapor dominated plumes from ash-dominated ones is important to better understand the atmospheric impact of these plumes.

  2. Oil-bearing sediments beneath San Juan volcanics - Colorado's newest frontier

    Energy Technology Data Exchange (ETDEWEB)

    Gries, R.R.

    1985-05-01

    During the Tertiary, the western part of the northern Sange de Cristo Range dropped 16,000 ft (4877 m) to become what is now known as the San Luis basin. The foreland basin formerly adjacent to and west of the range remained intact but was subsequently concealed by 10,000 ft (3048 m) of volcanic deposits. The existence of this concealed basin, a northeastern arm of the San Juan basin, was first suggested by Vincent Kelly who named it the San Juan sag. Oil, which was generated in the underlying Mancos Shale, migrated upward into vesicles and fractures in volcanic rocks. In at least two places, oil is currently seeping onto the volcanic surface or into overlying soil. These oil occurrences encouraged geologic and geophysical exploration and have led to confirmation by drilling that the basin exists. Porous reservoirs in both tertiary sedimentary rocks and volcanic rocks overlie a 2000 ft (610 m) Cretaceous Mancos Shale source rock. Within the Mancos Shale are fractured reservoirs, volcanic sills that have reservoir potential where fractured or porous, and stray sandstones. The Dakota Formation underlies the Mancos Shale and is about 200 ft (61 m) thick in this area. In addition, the Jurassic section has potential for source rocks in the Todilto Formation and reservoir rocks in the Entrada and Junction Creek Sandstones. The San Juan sag, a newly discovered basin of 2600 miS (6734 kmS) is a frontier for Colorado oil and gas exploration.

  3. Toward Forecasting Volcanic Eruptions using Seismic Noise

    CERN Document Server

    Brenguier, Florent; Campillo, Michel; Ferrazzini, Valerie; Duputel, Zacharie; Coutant, Olivier; Nercessian, Alexandre

    2007-01-01

    During inter-eruption periods, magma pressurization yields subtle changes of the elastic properties of volcanic edifices. We use the reproducibility properties of the ambient seismic noise recorded on the Piton de la Fournaise volcano to measure relative seismic velocity variations of less than 0.1 % with a temporal resolution of one day. Our results show that five studied volcanic eruptions were preceded by clearly detectable seismic velocity decreases within the zone of magma injection. These precursors reflect the edifice dilatation induced by magma pressurization and can be useful indicators to improve the forecasting of volcanic eruptions.

  4. Volcanic caves of East Africa - an overview

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    Jim W. Simons

    1998-01-01

    Full Text Available Numerous Tertiary to recent volcanoes are located in East Africa. Thus, much of the region is made up volcanic rock, which hosts the largest and greatest variety of East Africas caves. Exploration of volcanic caves has preoccupied members of Cave Exploration Group of East Africa (CEGEA for the past 30 years. The various publications edited by CEGEA are in this respect a treasure troves of speleological information. In the present paper an overview on the most important volcanic caves and areas are shortly reported.

  5. Breaking patient confidentiality: comparing Chilean and French viewpoints regarding the conditions of its acceptability

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    Cecilia Olivari

    2011-01-01

    Full Text Available The study examined the conditions under which lay people and health professionals living in Chile find it acceptable for a physician to break confidentiality to protect the wife of a patient with a sexually transmitted disease (STD. One hundred sixty-nine lay persons, 10 physicians, 17 psychologists, and 11 paramedical professionals indicated the acceptability of breaking confidentiality in 48 scenarios. The scenarios were all possible combinations of five factors: disease severity (severe, lethal; time taken to discuss this with the patient (little time, much time; patient’s intent to inform his spouse about the disease (none, one of these days, immediately; patient’s intent to adopt protective behaviors (no intent, intent; and physician’s decision to consult an STD expert (yes, no, 2 x 2 x 3 x 2 x 2. The study also compared Chilean and French views, using data gathered previously in France. A cluster analysis conducted on the overall set of raw data revealed groups of participants that found breaking confidentiality “always acceptable” (9%, requiring “consultation with an expert” (5%, “depending on the many circumstances” (70%, and “never acceptable” (11%”. Despite clear differences in legislation and official codes of ethics between their two countries, Chilean and French lay people did not differ much in their personal convictions regarding the circumstances in which patient confidentiality can be broken or must not be broken. By contrast, Chilean physicians, in agreement with their code of ethics, were much less supportive than French physicians of complete respect of patient confidentiality in all cases

  6. Identification of High Frequency Pulses from Earthquake Asperities Along Chilean Subduction Zone Using Strong Motion

    Science.gov (United States)

    Ruiz, S.; Kausel, E.; Campos, J.; Saragoni, G. R.; Madariaga, R.

    2011-01-01

    The Chilean subduction zone is one of the most active of the world with M = 8 or larger interplate thrust earthquakes occurring every 10 years or so on the average. The identification and characterization of pulses propagated from dominant asperities that control the rupture of these earthquakes is an important problem for seismology and especially for seismic hazard assessment since it can reduce the earthquake destructiveness potential. A number of studies of large Chilean earthquakes have revealed that the source time functions of these events are composed of a number of distinct energy arrivals. In this paper, we identify and characterize the high frequency pulses of dominant asperities using near source strong motion records. Two very well recorded interplate earthquakes, the 1985 Central Chile (Ms = 7.8) and the 2007 Tocopilla (Mw = 7.7), are considered. In particular, the 2007 Tocopilla earthquake was recorded by a network with absolute time and continuos recording. From the study of these strong motion data it is possible to identify the arrival of large pulses coming from different dominant asperities. The recognition of the key role of dominant asperities in seismic hazard assessment can reduce overestimations due to scattering of attenuation formulas that consider epicentral distance or shortest distance to the fault rather than the asperity distance. The location and number of dominant asperities, their shape, the amplitude and arrival time of pulses can be one of the principal factors influencing Chilean seismic hazard assessment and seismic design. The high frequency pulses identified in this paper have permitted us to extend the range of frequency in which the 1985 Central Chile and 2007 Tocopilla earthquakes were studied. This should allow in the future the introduction of this seismological result in the seismic design of earthquake engineering.

  7. Insulin resistance in Chileans of European and indigenous descent: evidence for an ethnicity x environment interaction.

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    Carlos A Celis-Morales

    Full Text Available BACKGROUND: Effects of urbanisation on diabetes risk appear to be greater in indigenous populations worldwide than in populations of European origin, but the reasons are unclear. This cross-sectional study aimed to determine whether the effects of environment (Rural vs. Urban, adiposity, fitness and lifestyle variables on insulin resistance differed between individuals of indigenous Mapuche origin compared to those of European origin in Chile. METHODOLOGY/PRINCIPAL FINDINGS: 123 Rural Mapuche, 124 Urban Mapuche, 91 Rural European and 134 Urban European Chilean adults had blood taken for determination of HOMA-estimated insulin resistance (HOMA(IR and underwent assessment of physical activity/sedentary behaviour (using accelerometry, cardiorespiratory fitness, dietary intake and body composition. General linear models were used to determine interactions with ethnicity for key variables. There was a significant "ethnicity x environment" interaction for HOMA(IR (Mean±SD; Rural Mapuche: 1.65±2.03, Urban Mapuche: 4.90±3.05, Rural European: 0.82±0.61, Urban European: 1.55±1.34, p((interaction = 0.0003, such that the effect of urbanisation on HOMA(IR was greater in Mapuches than Europeans. In addition, there were significant interactions (all p<0.004 with ethnicity for effects of adiposity, sedentary time and physical activity on HOMA(IR, with greater effects seen in Mapuches compared to Europeans, an observation that persisted after adjustment for potential confounders. CONCLUSIONS/SIGNIFICANCE: Urbanisation, adiposity, physical activity and sedentary behaviour influence insulin resistance to a greater extent in Chilean Mapuches than Chileans of European descent. These findings have implications for the design and implementation of lifestyle strategies to reduce metabolic risk in different ethnic groups, and for understanding of the mechanisms underpinning human insulin resistance.

  8. Memory, Citizenship and the Public Sphere in the Development of the Recent Past in the Chilean Experience

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    Graciela Rubio

    2013-07-01

    Full Text Available The research gets into to the studies of historical memory by performing a hermeneutic analysis of the discourse of memory and history narratives that the Chilean public discussion has used to develop its dictatorial recent past in the period 1991-2004. Press sources, editorial inserts, interviews with the social and political actors and specially Truth and Reconciliation Reports were reviewed. We reflect on the current oligarchic long and short term frames made for the representation of the public sphere and the citizenship, emphasizing the impossibility of forgiveness as a restorative category of the political community.It consolidates the symbolic weakness of the recovered democracyin recent Chilean history.

  9. TOWARD A HISTORY OF CHILEAN WRITTEN CULTURE. HAPPENINGS OF THE ALONSO DE ERCILLA’S BOOK, LA ARAUCANA.

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    Ariadna Biotti Silva

    2011-04-01

    Full Text Available The main objective of this paper is to present the first questioning about a history of the circulation of the book La Araucana, printed for the first time in 1569 and subsequently reprinted in various opportunities. Its central question implies a definition: What kind of historiography we can build considering the continuance, the force and the authority of a work that is still respected as a founding inheritance, and backbone of Chilean society? The paradigmatic center of this investigation resides in realizing the questions that emerge from the first chilean edition of the text published in Santiago in the year 1888.

  10. Evidence of recent deep magmatic activity at Cerro Bravo-Cerro Machín volcanic complex, central Colombia. Implications for future volcanic activity at Nevado del Ruiz, Cerro Machín and other volcanoes

    Science.gov (United States)

    Londono, John Makario

    2016-09-01

    In the last nine years (2007-2015), the Cerro Bravo-Cerro Machín volcanic complex (CBCMVC), located in central Colombia, has experienced many changes in volcanic activity. In particular at Nevado del Ruiz volcano (NRV), Cerro Machin volcano (CMV) and Cerro Bravo (CBV) volcano. The recent activity of NRV, as well as increasing seismic activity at other volcanic centers of the CBCMVC, were preceded by notable changes in various geophysical and geochemical parameters, that suggests renewed magmatic activity is occurring at the volcanic complex. The onset of this activity started with seismicity located west of the volcanic complex, followed by seismicity at CBV and CMV. Later in 2010, strong seismicity was observed at NRV, with two small eruptions in 2012. After that, seismicity has been observed intermittently at other volcanic centers such as Santa Isabel, Cerro España, Paramillo de Santa Rosa, Quindío and Tolima volcanoes, which persists until today. Local deformation was observed from 2007 at NRV, followed by possible regional deformation at various volcanic centers between 2011 and 2013. In 2008, an increase in CO2 and Radon in soil was observed at CBV, followed by a change in helium isotopes at CMV between 2009 and 2011. Moreover, SO2 showed an increase from 2010 at NRV, with values remaining high until the present. These observations suggest that renewed magmatic activity is currently occurring at CBCMVC. NRV shows changes in its activity that may be related to this new magmatic activity. NRV is currently exhibiting the most activity of any volcano in the CBCMVC, which may be due to it being the only open volcanic system at this time. This suggests that over the coming years, there is a high probability of new unrest or an increase in volcanic activity of other volcanoes of the CBCMVC.

  11. Border dimension of Chilean foreign policies: Immobility and urgency of new dynamics

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    Cristian Ovando Santana

    2011-07-01

    Full Text Available The following article draws the priorities of border public policy that define the Chilean foreign policy. Through a theoretical framework from the rational–reflective approach of International Relations, we argue that despite of the increasing openness, internationalization of the country, and the emergence of new actors and subnational initiatives; the views and options between the actors of this new area and the definitions of foreign policy not always match. We propose the need to establish mechanisms that settle the positions among regional social–political actors, intermediate agencies and the central level.

  12. Results on the neutron energy distribution measurements at the RECH-1 Chilean nuclear reactor

    Science.gov (United States)

    Aguilera, P.; Molina, F.; Romero-Barrientos, J.

    2016-07-01

    Neutron activations experiments has been perform at the RECH-1 Chilean Nuclear Reactor to measure its neutron flux energy distribution. Samples of pure elements was activated to obtain the saturation activities for each reaction. Using - ray spectroscopy we identify and measure the activity of the reaction product nuclei, obtaining the saturation activities of 20 reactions. GEANT4 and MCNP was used to compute the self shielding factor to correct the cross section for each element. With the Expectation-Maximization algorithm (EM) we were able to unfold the neutron flux energy distribution at dry tube position, near the RECH-1 core. In this work, we present the unfolding results using the EM algorithm.

  13. Strategic Evolution of Chilean Wine Firms: Vertical Integration and Upgrading in Chile’s Colchagua Valley

    OpenAIRE

    Robert N. Gwynne

    2012-01-01

    This paper argues that the favourable export trajectories for Chilean wine to global markets in general and the UK market in particular are partly due to the nature of the insertion of wine producing firms into global value chains. Much of the data in this paper comes from a two-year British Academy research project (2005-07) which examined the impacts of globalization on export-oriented wine firms in Chile’s Colchagua Valley and the record of collaboration between these firms and key purchas...

  14. International expansion of the chilean wine industry: ann empirical study concerning the factors and exportation level

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    Sammy Liberman

    2010-05-01

    Full Text Available This study proposes a set of variables which are decisive in the international expansion of the Chilean Wine Industry: i company size; ii quality management; iii communication and information technologies; iv international management planning; and finally, v implementation of the international marketing strategy. Results based on data between 2004 and 2007 allow to confirm six of the seven formulated hypotheses. The implications of these findings for theory and practice are discussed, as well as the main limitations. Finally, we offer some recommendations for further research.

  15. Misconceptions of the p-value among Chilean and Italian Academic Psychologists.

    Science.gov (United States)

    Badenes-Ribera, Laura; Frias-Navarro, Dolores; Iotti, Bryan; Bonilla-Campos, Amparo; Longobardi, Claudio

    2016-01-01

    Common misconceptions of p-values are based on certain beliefs and attributions about the significance of the results. Thus, they affect the professionals' decisions and jeopardize the quality of interventions and the accumulation of valid scientific knowledge. We conducted a survey on 164 academic psychologists (134 Italian, 30 Chilean) questioned on this topic. Our findings are consistent with previous research and suggest that some participants do not know how to correctly interpret p-values. The inverse probability fallacy presents the greatest comprehension problems, followed by the replication fallacy. These results highlight the importance of the statistical re-education of researchers. Recommendations for improving statistical cognition are proposed. PMID:27602007

  16. Mano a Mano-Mujer: an effective HIV prevention intervention for Chilean women.

    Science.gov (United States)

    Cianelli, Rosina; Ferrer, Lilian; Norr, Kathleen F; Miner, Sarah; Irarrazabal, Lisette; Bernales, Margarita; Peragallo, Nilda; Levy, Judith; Norr, James L; McElmurry, Beverly

    2012-01-01

    The impact of a professionally facilitated peer group intervention for HIV prevention among 400 low-income Chilean women was examined using a quasiexperimental design. At 3 months postintervention, the intervention group had higher HIV-related knowledge, more positive attitudes toward people living with HIV, fewer perceived condom use barriers, greater self- efficacy, higher HIV reduction behavioral intentions, more communication with partners about safer sex, and decreased depression symptoms. They did not, however, have increased condom use or self-esteem. More attention to gender barriers is needed. This intervention offers a model for reducing HIV for women in Chile and other Latin American countries.

  17. Misconceptions of the p-value among Chilean and Italian Academic Psychologists

    Science.gov (United States)

    Badenes-Ribera, Laura; Frias-Navarro, Dolores; Iotti, Bryan; Bonilla-Campos, Amparo; Longobardi, Claudio

    2016-01-01

    Common misconceptions of p-values are based on certain beliefs and attributions about the significance of the results. Thus, they affect the professionals' decisions and jeopardize the quality of interventions and the accumulation of valid scientific knowledge. We conducted a survey on 164 academic psychologists (134 Italian, 30 Chilean) questioned on this topic. Our findings are consistent with previous research and suggest that some participants do not know how to correctly interpret p-values. The inverse probability fallacy presents the greatest comprehension problems, followed by the replication fallacy. These results highlight the importance of the statistical re-education of researchers. Recommendations for improving statistical cognition are proposed. PMID:27602007

  18. Extraction Techniques for Bioactive Compounds and Antioxidant Capacity Determination of Chilean Papaya (Vasconcellea pubescens) Fruit

    OpenAIRE

    Elsa Uribe; Alvaro Delgadillo; Claudia Giovagnoli-Vicuña; Issis Quispe-Fuentes; Liliana Zura-Bravo

    2015-01-01

    The aim of this work was to assess and compare different extraction methods by using high hydrostatic pressure (HHPE), ultrasound (UE), agitation (AE), and their combinations for the extraction of bioactive compounds of Chilean papaya. Extract antioxidant capacity was evaluated by three methods (i.e., DPPH, FRAP, and Voltammetry) and phenolic compounds and vitamin C were determined by HPLC. Papaya sample extraction was performed by HHPE at 500 MPa for 10 min and UE and AE for 30 min, respecti...

  19. A chromosomal analysis of four species of Chilean Chrysomelinae (Coleoptera, Chrysomelidae

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    Eduard Petitpierre

    2012-10-01

    Full Text Available Four species of Chilean leaf beetles in the subfamily Chrysomelinae have been cytogenetically analyzed, Blaptea elguetai Petitpierre, 2011, Henicotherus porteri Bréthes, 1929 and Jolivetia obscura (Philippi, 1864 show 2n = 28 chromosomes and a 13 + Xyp male meioformula, and Pataya nitida (Philippi, 1864 has the highest number of 2n = 38 chromosomes. The karyotype of H. porteri is made of mostly small meta/submetacentric chromosomes, and that of Jolivetia obscura displays striking procentric blocks of heterochromatin at pachytene autosomic bivalents using conventional staining. These findings are discussed in relation to previous cytogenetic data and current taxonomy of the subfamily.

  20. Level of evidence and geographic origin of articles published in Chilean dental journals.

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    Javier Moraga

    2014-03-01

    Full Text Available ABSTRACT The aim of this study is to determine the geographic origin and level of evidence (LE of articles published in Chilean dental journals during 2012. The target population for the bibliometric study was articles published in exclusively-scientific Chilean dental journals. These variables were analyzed: journal, area, language, country, region, design, scenario, and LE. A total of 120 articles were published in four journals: International Journal of Odontostomatology (IJOS=59, Revista Clínica de Periodoncia, Implantología y Rehabilitación Oral (PIRO=28, Journal of Oral Research (JOR=18, and Revista Dental de Chile (RDC=15. From the total, 80.83% were published in Spanish and 70% had a Chilean affiliation. Most publications corresponded to areas of pathology (21 others (20 and prosthodontics (20. None of the articles was Level 1 Evidence, 6.49% was 2b, 14.29% was 2c, 63.64% was 4, and 15.58 % was 5. Chilean dental journals mainly publish articles of domestic origin and low LE. RESUMEN El objetivo de esta investigación es determinar el origen y nivel de evidencia (NE de los artículos publicados en las revistas odontológicas chilenas durante el año 2012. Estudio bibliométrico, la población objetivo fueron todos los artículos publicados en revistas dentales chilenas de orientación exclusivamente científica. Se analizaron variables: Revista, Área, Idioma, País, Región, Diseño, Escenario y NE. Se hallaron 120 artículos publicados en cuatro revistas: International Journal of Odontostomatology (IJOS = 59, Revista Clínica de Periodoncia, Implantología y Rehabilitación Oral (PIRO = 28, Journal of Oral Research (JOR = 18 y Revista Dental de Chile (RDC = 15. El 80.83% de los artículos fue publicado en español y el 70% corresponden a autores chilenos. La mayor cantidad de publicaciones correspondieron a las áreas de Patología (21, Otra (20 y Prostodoncia (20. No se hallaron artículos de NE 1, 6.49% fue 2b, 14.29% fue 2c, 63

  1. Use of remote sensing to model ungauged Chilean basins

    Science.gov (United States)

    Vasquez, Nicolas; Vargas, Ximena

    2016-04-01

    Calibration of hydrological models is usually performed in gauged basins with streamflow data, which is the result of the hydrological cycle processes, due to a poor monitoring system of other processes like melting, infiltration, evapotranspiration or sublimation. This approach can generate several parameters combinations with similar streamflow results and choosing a reliable set of parameters can be challenging, especially in ungauged basins. Remote sensing can be useful because is an additional source of ungauged variables, and is distributed in space and time. This is valuable information related to the processes of hydrological cycle, and it helps to represent the basin with physically based models where the focus is on the processes, such as the Cold Regional Hydrological Model (CRHM). There are several satellites products related to the hydrological cycle such as snow covered area, albedo, evapotranspiration or surface temperature, in the case of MODIS, rain rate from TRMM, Soil moisture from SMOS or snow water equivalent (SWE) from AMSR, and these can be used to improve the representation of the processes in a basin or, in the case of this work, to estimate stream flow using remote sensing only. The study area is Elqui River, in northern Chile, with a semi-arid mediterranean climate and a snow driven regime due to the Andes, where snow accumulation and snowmelt control water availability and the maximum snow covered area reach 50% of the total basin. Several satellite products related principally to snow are considered to represent the variation of the snowpack in space and time as inputs to the model or as state variables.

  2. On the Role of Climate Forcing by Volcanic Sulphate and Volcanic Ash

    OpenAIRE

    Baerbel Langmann

    2014-01-01

    There is overall agreement that volcanic sulphate aerosols in the stratosphere can reduce solar radiation reaching the earth’s surface for years, thereby reducing surface temperatures, affecting global circulation patterns and generally the global climate system. However, the response of the climate system after large volcanic eruptions is not fully understood and global climate models have difficulties to reproduce the observed variability of the earth system after large volcanic eruptions u...

  3. Co-evolution of volcanic catchments in Japan

    Science.gov (United States)

    Yoshida, T.; Troch, P. A. A.

    2015-12-01

    Present day landscapes have evolved over time through interactions between the prevailing climates and geological settings. Understanding the linkage between spatial patterns of landforms, soils, and vegetation in landscapes and their hydrological response is critical to make quantitative predictions in ungaged basins. Catchment co-evolution is a theoretical framework that seeks to formulate hypotheses about the mechanisms and conditions that determine the historical development of catchments and how such evolution affects their hydrological response. In this study, we selected 14 volcanic catchments of different ages (from 0.22 to 82Ma) in Japan. We derived indices of landscape properties (drainage density) as well as hydrological response (annual water balance, baseow index, and flow duration curves) and examined their relation with catchment age and climate (through the aridity index). We found signicant correlation between drainage density and baseow index with age, but not with climate. The age of the catchments was also signicantly related to intra-annual flow variability. Younger catchments tend to have lower peak flows and higher low flows, while older catchments exhibit more flashy runoff. The decrease of baseflow with catchment age confirms previous studies that hypothesized that in volcanic landscapes the major flow pathways have changed over time, from deep groundwater flow to shallow subsurface flow. The drainage density of our catchments decreased with age, contrary to previous findings in similar volcanic catchments but of signicant younger age than the ones explored here. In these younger catchments, an increase in drainage density with age was observed, and it was hypothesized that this was because of more landscape incision due to increasing near-surface lateral flow paths in more mature catchments. Our results suggest that as catchments further evolve, hydrologically active channels retreat as less recharge leads to lower average aquifer levels

  4. Volcanic and sedimentary-rock aquifers

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set represents the extent of the Volcanic and sedimentary-rock aquifers in the states of Montana, Wyoming, Idaho, Nevada, California, Oregon, and...

  5. Volcanics in the Gulf Coast [volcanicg

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The volcanic provinces are modified after Plate 2, Principal structural features, Gulf of Mexico Basin (compiled by T.E. Ewing and R.F. Lopez) in Volume J, The...

  6. Volcanic Ash Advisory Database, 1983-2003

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Volcanic ash is a significant hazard to aviation and can also affect global climate patterns. To ensure safe navigation and monitor possible climatic impact, the...

  7. Medical effects of volcanic eruptions

    Science.gov (United States)

    Baxter, Peter J.

    1990-09-01

    Excluding famine and tsunamis, most deaths in volcanic eruptions have been from pyroclastic flows and surges (nuées ardentes) and wet debris flows (lahars). Information on the causes of death and injury in eruptions is sparse but the available literature is summarised for the benefit of volcanologists and emergency planners. In nuées, thermal injury may be at least as important as asphyxia in causing immediate deaths. The high temperature of the gases and entrained particles readily causes severe burns to the skin and the air passages and the presence of both types of injury in an individual may combine to increase the delayed mortality risk from respiratory complications or from infection of burns. Trauma from missiles or body displacement is also common, but the role of asphyxiant or irritant gases, and steam, remains unclear. The ratio of dead: injured is much higher than in other natural disasters. At the periphery of a nuée being protected inside buildings which remain intact appears to greatly increase the chances of survival. In lahars, infected wounds and crush injury are the main delayed causes of death, and the scope for preventive measures, other than evacuation, is small. The evidence from Mount St. Helens, 1980, and other major eruptions indicates that, although mortality is high within the main zone of devastation and in the open, emergency planning should concentrate on the periphery of a nuée where preventive measures are feasible and could save many lives in densely populated areas.

  8. Crossing the glass transition during volcanic eruptions

    OpenAIRE

    Richard, Dominique

    2015-01-01

    Predicting the occurrence and the evolving nature of volcanic eruptions remains an outstanding challenge. The complexity of volcanic Systems requires the use of many different approaches to gain a more profound understanding of the interplay of parameters such as magma temperature, composition, volatile content, cooling rate and viscosity as they interactively control the rheology of magma. This study focusses on three different scenarios in which the glass transition, a kinetic boundar...

  9. Volcanic ash detection by GPS signal

    OpenAIRE

    Aranzulla, M.; Dipartimento di Fisica e Astronomia, Università di Catania; Cannavò, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; Scollo, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; Puglisi, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; Immè, G.; sita` degli studi di Catania

    2013-01-01

    We investigate the ability of GPS to detect volcanic plumes at Mt. Etna, Italy. We use a robust statistical approach to highlight whether the presence of a volcanic plume in the atmosphere may really affect the GPS undifferenced post-fit phase residuals. The proposed method has been tested for the September 4–5, 2007 activity of Mt. Etna. This eruption produced powerful lava fountains forming a weak, a few kilometers high plume for several hours, representing typical a...

  10. Ash Redistribution Following a Potential Volcanic Eruption at Yucca Mountain

    Science.gov (United States)

    Pelletier, J. D.; Delong, S. B.; Cline, M. L.; Harrington, C. D.; Keating, G.

    2005-12-01

    The redistribution of contaminated tephra by hillslope, fluvial, and pedologic processes is a poorly-constrained but important aspect of evaluating the radiological dose from an unlikely volcanic eruption at Yucca Mountain (YM). To better evaluate this hazard, we developed a spatially-distributed numerical model of tephra redistribution that integrates contaminated tephra from hill slopes and active channels, mixes it with clean sediment in the channel system, distributes it on the fan, and migrates it into the soil column. The model is coupled with an atmospheric dispersion model that predicts the deposition of radioactive waste-contaminated tephra at specified grid points. The redistribution model begins in the upper Fortymile Wash drainage basin where it integrates the tephra deposited on steep slopes and active channel beds within a spatially-distributed framework. The Fortymile Wash drainage basin is the focus of this model because tephra from only this basin reaches the Fortymile Wash alluvial fan by fluvial processes, and it is on this fan where the radiological dose to a hypothetical individual is compared to the regulatory standard (via additional biosphere models). The dilution effect of flood scour, mixing, and re-deposition within the upper basin is modeled using a dilution-mixing model widely used in the contaminant-transport literature. The accuracy of this model is established by comparing the model prediction with tephra concentrations measured in channels draining the Lathrop Wells volcanic center. The model combines the contaminated tephra transported from the upper basin with the tephra deposited directly on the fan as primary fallout. On the Fortymile Wash fan, channels and interchannel-divide areas are divided on the basis of soil-geomorphic mapping according to whether they are Holocene or Pleistocene in age. This approach allows the model to incorporate the effects of channel migration on the fan within the past 10,000 yr. The model treats

  11. Lunar volcanism in space and time

    Science.gov (United States)

    Head, J. W., III

    1976-01-01

    The role of lunar volcanism in the history of the moon is documented using lunar-orbit and earth-based data along with characterizations derived from Apollo and Luna sample-return missions. Characteristics of mare and highland volcanic features are described, Apollo and Luna results are discussed, and the characteristics of other mare deposits and of other highland features of possible volcanic origin are summarized. Major conclusions are that: (1) there is little unequivocal morphologic evidence for highland volcanism, (2) lunar mare lavas appear to have originated from depths of 100 to 500 km, (3) impact melting does not appear to have been a factor in the generation of mare lavas, (4) mare volcanism was characterized by massive outpourings of very fluid volatile-poor lava analogous to terrestrial flood basalts, (5) mare volcanism took place from 3.83 to about 2.5 billion years ago, (6) the preferential occurrence of mare deposits in large impact basins appears to be generically unrelated to basin formation, and (7) a thicker farside crust may be responsible for the distinctive nearside-farside asymmetry of mare deposits.

  12. Volcanic loading: The dust veil index

    Energy Technology Data Exchange (ETDEWEB)

    Lamb, H.H. [Univ. of East Anglia, Norwich (United Kingdom). Climatic Research Unit

    1985-09-01

    Dust ejected into the high atmosphere during explosive volcanic eruptions has been considered as a possible cause for climatic change. Dust veils created by volcanic eruptions can reduce the amount of light reaching the Earth`s surface and can cause reductions in surface temperatures. These climatic effects can be seen for several years following some eruptions and the magnitude and duration of the effects depend largely on the density or amount of tephra (i.e. dust) ejected, the latitude of injection, and atmospheric circulation patterns. Lamb (1970) formulated the Dust Veil Index (DVI) in an attempt to quantify the impact on the Earth`s energy balance of changes in atmospheric composition due to explosive volcanic eruptions. The DVI is a numerical index that quantifies the impact on the Earth`s energy balance of changes in atmospheric composition due to explosive volcanic eruptions. The DVI is a numerical index that quantifies the impact of a particular volcanic eruptions release of dust and aerosols over the years following the event. The DVI for any volcanic eruptions are available and have been used in estimating Lamb`s dust veil indices.

  13. Antioxidant activity and phenolic profiles of the wild currant Ribes magellanicum from Chilean and Argentinean Patagonia.

    Science.gov (United States)

    Jiménez-Aspee, Felipe; Thomas-Valdés, Samanta; Schulz, Ayla; Ladio, Ana; Theoduloz, Cristina; Schmeda-Hirschmann, Guillermo

    2016-07-01

    The Patagonian currant Ribes magellanicum is highly valued due to its pleasant flavor and sweet taste. The aim of this study was to characterize its constituents and to assess their antioxidant and cytoprotective properties. For the fruit phenolic-enriched extract (PEE), total phenolics (TP), total flavonoids (TF), and antioxidant activity (DPPH, Ferric reducing antioxidant power (FRAP), and Trolox equivalent antioxidant activity (TEAC)) were determined. Argentinean samples presented better activity in the DPPH and FRAP assays. Best cytoprotection against oxidative stress induced by H2O2 in AGS cells was found in one Argentinean sample at 500 μg mL(-1) (65.7%). HPLC MS/MS analysis allowed the tentative identification of 59 constituents, including eight anthocyanins, 11 conjugates of caffeic-, ferulic-, and coumaric acid, and 38 flavonoids, most of them quercetin and kaempferol derivatives. Argentinean samples showed a more complex pattern of anthocyanins, hydroxycinnamic acids (HCA), and flavonoids. Cyanidin rhamnoside hexoside and cyanidin hexoside were the main anthocyanins, accounting for 35 and 55% for the Argentinean and 60 and 27% for the ripe Chilean fruits. HCA content was about three times higher in Argentinean samples. The phenolic profiles of Chilean and Argentinean Ribes magellanicum show remarkable differences in chemical composition with higher HCA and flavonoid content in Argentinean samples. PMID:27386109

  14. Profiling Space Heating Behavior in Chilean Social Housing: Towards Personalization of Energy Efficiency Measures

    Directory of Open Access Journals (Sweden)

    Victor Bunster

    2015-06-01

    Full Text Available Global increases in the demand for energy are imposing strong pressures over the environment while compromising the capacity of emerging economies to achieve sustainable development. In this context, implementation of effective strategies to reduce consumption in residential buildings has become a priority concern for policy makers as minor changes at the household scale can result in major energy savings. This study aims to contribute to ongoing research on energy consumer profiling by exploring the forecasting capabilities of discrete socio-economic factors that are accessible through social housing allocation systems. Accordingly, survey data gathered by the Chilean Ministry of Social Development was used identify key characteristics that may predict firewood usage for space heating purposes among potential beneficiaries of the Chilean social housing program. The analyzed data evidences strong correlations between general household characteristics and space heating behavior in certain climatic zones, suggesting that personalized delivery of energy efficiency measures can potentially increase the effectiveness of initiatives aimed towards the reduction of current patterns of consumption.

  15. IL28B polymorphisms associated with therapy response? ein inin Chilean chronic hepatitis C patients

    Institute of Scientific and Technical Information of China (English)

    Mauricio Venegas; Rodrigo A Villanueva; Katherine González; Javier Brahm

    2011-01-01

    AIM: To analyze the association of three IL28B single nucleotide polymorphisms with response to therapy in Chilean patients infected with hepatitis C virus (HCV).((HHCV))).. METHODS: We studied two groups of patients with chronic HHCV infection ((genotype 1)), under standard combined treatment with pegylated interferon plus ribavirin. One group consisted of 50 patients with sustained virological response, whereas the second group consisted of 49 null responders. In order to analyze the IL28B single nucleotide polymorphisms rs12979860, rs12980275 and rs8099917, samples were used for polymerase chain reaction amplification, and the genotyping was performed by restriction fragment length polymorphism. RESULTS: The IL28B rs12979860 CC, rs12980275 AA and rs8099917 TT genotypes were much more frequently found in patients with sustained virological response compared to null responders ((38%, 44% and 50% vs 2%, 8.2% and 8.2%, respectively)). These differences were highly significant in all three cases (P < 0.0001)). CONCLUSION: The three IL28B polymorphisms studied are strongly associated with sustained virological response to therapy in Chilean patients with chronic HHCV ((genotype 1)).

  16. Associations between different components of fitness and fatness with academic performance in Chilean youths

    Science.gov (United States)

    2016-01-01

    Objectives To analyze the associations between different components of fitness and fatness with academic performance, adjusting the analysis by sex, age, socio-economic status, region and school type in a Chilean sample. Methods Data of fitness, fatness and academic performance was obtained from the Chilean System for the Assessment of Educational Quality test for eighth grade in 2011 and includes a sample of 18,746 subjects (49% females). Partial correlations adjusted by confounders were done to explore association between fitness and fatness components, and between the academic scores. Three unadjusted and adjusted linear regression models were done in order to analyze the associations of variables. Results Fatness has a negative association with academic performance when Body Mass Index (BMI) and Waist to Height Ratio (WHR) are assessed independently. When BMI and WHR are assessed jointly and adjusted by cofounders, WHR is more associated with academic performance than BMI, and only the association of WHR is positive. For fitness components, strength was the variable most associated with the academic performance. Cardiorespiratory capacity was not associated with academic performance if fatness and other fitness components are included in the model. Conclusions Fitness and fatness are associated with academic performance. WHR and strength are more related with academic performance than BMI and cardiorespiratory capacity. PMID:27761345

  17. APOE Polymorphisms Contribute to Reduced Atorvastatin Response in Chilean Amerindian Subjects

    Directory of Open Access Journals (Sweden)

    Jenny Lagos

    2015-04-01

    Full Text Available Genetic factors can determine the high variability observed in response to lipid-lowering therapy with statins. Nonetheless, the frequency of single nucleotide polymorphisms (SNPs and their impact can vary due to ethnicity. Because the Chilean population carries a strong Amerindian background, the objective of this study was to evaluate the influence of apolipoprotein E (APOE variants (rs429358, rs7412 and the 1959C>T SNP (rs5925 in the low-density lipoprotein receptor (LDLR in response to atorvastatin treatment in hypercholesterolemic individuals. A hundred and thirty nine subjects undergoing statin therapy were included. Identification of Amerindian mtDNA haplogroups was determined by polymerase chain reaction (PCR and PCR followed by restriction fragment length polymorphism (RFLP, respectively. SNPs were determined by PCR-RFLP. Out of the 139 individuals studied, 84.4% had an Amerindian background, according to mtDNA analysis. In relation to APOE variants, carriers of the E3/4 genotype presented lower cholesterol reduction compared to genotype E3/3 (LDL-C: −18% vs. −29%, p ˂ 0.001. On the other hand, the LDLR rs5925 SNP was not related to atorvastatin response (p = 0.5760. Our results suggest that APOE SNPs are potential predictors to atorvastatin therapy in Amerindian Chilean subjects.

  18. The Epidemiology of Sleep Quality and Consumption of Stimulant Beverages among Patagonian Chilean College Students

    Directory of Open Access Journals (Sweden)

    Juan Carlos Vélez

    2013-01-01

    Full Text Available Objectives. (1 To assess sleep patterns and parameters of sleep quality among Chilean college students and (2 to evaluate the extent to which stimulant beverage use and other lifestyle characteristics are associated with poor sleep quality. Methods. A cross-sectional study was conducted among college students in Patagonia, Chile. Students were asked to complete a self-administered questionnaire to provide information about lifestyle and demographic characteristics. The Pittsburgh Sleep Quality Index (PSQI was used to evaluate sleep quality. In addition, students underwent a physical examination to collect anthropometric measurements. Results. More than half of students (51.8% exhibited poor sleep quality. Approximately 45% of study participants reported sleeping six hours or less per night and 9.8% used medications for sleep. In multivariate analysis, current smokers had significantly greater daytime dysfunction due to sleepiness and were more likely to use sleep medicines. Students who reported consumption of any stimulant beverage were 1.81 times as likely to have poor sleep quality compared with those who did not consume stimulant beverages (OR:1.81, 95% CI:1.21–2.00. Conclusions. Poor sleep quality is prevalent among Chilean college students, and stimulant beverage consumption was associated with the increased odds of poor sleep quality in this sample.

  19. Utilization of therapies for stress management in Chilean clinical dental students.

    Directory of Open Access Journals (Sweden)

    Francisco Pérez

    2015-12-01

    Full Text Available Dental students suffer greater stress than the rest of the university population. In general, most health students seek little assistance to help them cope with stress. The aim of this study is to evaluate the use of therapies to manage stress in Chilean clinical dental students. A cross-sectional study was conducted nationwide; this report is a secondary data analysis. The study population was dental students in clinical years (4th and 5th of 5 Chilean dental schools: Antofagasta, Valparaíso, Viña del Mar, Concepción, and La Frontera. This paper reports the use of therapies for stress management during the past six months considering four options: medical/psychiatric, psychological, self-medication and alternative. Tabulation and analysis were done in STATA 10/SE. Three hundred thirty-seven students were surveyed, 54.01% were men and 64.99% were in fourth year, with an average age of 22.94 ±2.04. The 48.07% of students have used any of the four types of therapies; women and fourth-year students use more any form of therapy with 53.30% (p=.037 and 48.86% (p=.694, respectively, than men and fifth year students. About half of the students have used some form of therapy to manage stress in the last six months; of the students that received therapy, the percentage of women was significantly higher.

  20. The Epidemiology of Sleep Quality and Consumption of Stimulant Beverages among Patagonian Chilean College Students.

    Science.gov (United States)

    Vélez, Juan Carlos; Souza, Aline; Traslaviña, Samantha; Barbosa, Clarita; Wosu, Adaeze; Andrade, Asterio; Frye, Megan; Fitzpatrick, Annette L; Gelaye, Bizu; Williams, Michelle A

    2013-01-01

    Objectives. (1) To assess sleep patterns and parameters of sleep quality among Chilean college students and (2) to evaluate the extent to which stimulant beverage use and other lifestyle characteristics are associated with poor sleep quality. Methods. A cross-sectional study was conducted among college students in Patagonia, Chile. Students were asked to complete a self-administered questionnaire to provide information about lifestyle and demographic characteristics. The Pittsburgh Sleep Quality Index (PSQI) was used to evaluate sleep quality. In addition, students underwent a physical examination to collect anthropometric measurements. Results. More than half of students (51.8%) exhibited poor sleep quality. Approximately 45% of study participants reported sleeping six hours or less per night and 9.8% used medications for sleep. In multivariate analysis, current smokers had significantly greater daytime dysfunction due to sleepiness and were more likely to use sleep medicines. Students who reported consumption of any stimulant beverage were 1.81 times as likely to have poor sleep quality compared with those who did not consume stimulant beverages (OR:1.81, 95% CI:1.21-2.00). Conclusions. Poor sleep quality is prevalent among Chilean college students, and stimulant beverage consumption was associated with the increased odds of poor sleep quality in this sample. PMID:23766919

  1. Quality of life among caregivers of patients with schizophrenia: a cross-cultural comparison of Chilean and French families

    Directory of Open Access Journals (Sweden)

    Boyer Laurent

    2012-07-01

    Full Text Available Abstract Background To our knowledge, no study has examined quality of life (QoL among caregivers of individuals with schizophrenia between a developing and a developed country. The aim of this study was to assess QoL of the caregivers of individuals with schizophrenia in two countries characterized by different social, economic and cultural conditions, namely Chile and France. Methods Data were collected from public mental health outpatient services in Arica (Chile, and in Marseille (France. QoL was measured with the short-form health survey scale - 36 items (SF36. QoL of 41 Chilean caregivers was firstly compared with 245 French caregivers. Univariate and multivariate analyses using linear regression were then performed to determine variables potentially related to QoL scores. Results The caregivers were primarily mothers in the two groups, but Chilean caregivers were younger, and lived more frequently with the individual with schizophrenia than French caregivers. The SF36 scores were globally low in the two groups, especially on the mental QoL scores. Chilean caregivers reported lower physical SF36 scores than French caregivers. In the multivariate analysis, being mother and Chilean caregivers were the most regular features associating to a lower QoL. Conclusion Despite differences between Chile and France, especially in terms of quality and quantity of mental health services and economic supports, caregivers’ QoL levels remain particularly low for both countries. Future support programmes should address the specific needs of caregivers.

  2. Inter-subjectivity and Domestication in the Making of a Global Region: Territorialization of Salmon in the Chilean Patagonia.

    NARCIS (Netherlands)

    Blanco, Gustavo; Arce, A.M.G.; Fisher, E.F.

    2016-01-01

    This article examines transformations in the Chilean Patagonia, a region that has become a world leader in Salmon production for global markets. Employing ethnographic methods, this study examines the possibilities of considering inter-subjectivities in the processes of conforming important regions

  3. Increasing Students' Academic Involvement: Chilean Teacher Engagement with Learners in Blended English as a Foreign Language Courses

    Science.gov (United States)

    Johnson, Christopher P.

    2013-01-01

    Learning English as a foreign language (EFL), a highly valued skill in the Chilean marketplace, is an arduous and complex personal endeavor requiring high student motivation. Reflecting this challenge is the heightened anxiety among EFL students, whose work has been associated with historically meager results. Blended learning, the fusion of…

  4. Variation in implementation of corporate social responsibility practices in emerging economies' firms: A survey of Chilean fruit exporters

    NARCIS (Netherlands)

    Klerkx, L.W.A.; Villalobos, P.; Engler, A.

    2012-01-01

    As in many sectors in emerging economies, the concept of corporate social responsibility (CSR) has become important for exporting agri-food firms in view of their integration in global supply chains. The purpose of this research was to assess the implementation by Chilean fruit exporters of CSR prac

  5. Adolescent Temperament and Parental Control in the Development of the Adolescent Decision Making in a Chilean Sample

    Science.gov (United States)

    Perez, J. Carola; Cumsille, Patricio

    2012-01-01

    The study analyzes the way in which adolescents' temperamental characteristics interact with parental control to shape adolescent decision making development. A sample of high-school Chilean adolescents (N = 391) answered a self-report questionnaire that included measures of behavioral autonomy (the extent to which adolescents make decisions in…

  6. Culture-Dependent and Independent Studies of Microbial Diversity in Highly Copper-Contaminated Chilean Marine Sediments

    NARCIS (Netherlands)

    L. Besaury; F. Marty; S. Buquet; V. Mesnage; G. Muijzer; L. Quillet

    2013-01-01

    Cultivation and molecular-based approaches were used to study microbial diversity in two Chilean marine sediments contaminated with high (835 ppm) and very high concentrations of copper (1,533 ppm). The diversity of cultivable bacteria resistant to copper was studied at oxic and anoxic conditions, f

  7. THE MAKING OF AN UNLIKELY CHILEAN FASCIST: REFLECTIONS ON THE INTELLECTUAL DEVELOPMENT AND POLITICAL WORK OF CARLOS KELLER RUEFF

    Directory of Open Access Journals (Sweden)

    Marcus Klein

    2002-01-01

    Full Text Available This article deals with the intellectual evolution and political activities of Carlos Keller Rueff between the early 1920s and the late 1930s. It discusses his development from a German nationalist to a Chilean fascist during the course of this eventful period. In the 1920s Keller, who started his career in the Deutsch-Chilenischer Bund, the umbrella organisation of the German-Chilean community, expressed German National positions. Only at the end of the decade he began to distance himself from his narrow, sectarian German sub-culture and took a broader, national view, a development that coincided with his move from Concepción to Santiago and the failure of his plan to revive the immigration of Germans to Chile. With the book La eterna crisis chilena, published in 1931, he finally emerged as a Chilean nationalist and gained the reputation of an intellectual. One year later, in April 1932, he was, together with Jorge González von Marées, one of the founding members of the Chilean Movimiento Nacional Socialista (MNS. Keller became the movement’s ideologue and its second most prominent leader. This career abruptly ended with the failed nacista coup of 5 September 1938 and the subsequent transformation of the MNS into the Vanguardia Popular Socialista

  8. Volcanic Alert System (VAS) developed during the (2011-2013) El Hierro (Canary Islands) volcanic process

    Science.gov (United States)

    Ortiz, Ramon; Berrocoso, Manuel; Marrero, Jose Manuel; Fernandez-Ros, Alberto; Prates, Gonçalo; De la Cruz-Reyna, Servando; Garcia, Alicia

    2014-05-01

    In volcanic areas with long repose periods (as El Hierro), recently installed monitoring networks offer no instrumental record of past eruptions nor experience in handling a volcanic crisis. Both conditions, uncertainty and inexperience, contribute to make the communication of hazard more difficult. In fact, in the initial phases of the unrest at El Hierro, the perception of volcanic risk was somewhat distorted, as even relatively low volcanic hazards caused a high political impact. The need of a Volcanic Alert System became then evident. In general, the Volcanic Alert System is comprised of the monitoring network, the software tools for the analysis of the observables, the management of the Volcanic Activity Level, and the assessment of the threat. The Volcanic Alert System presented here places special emphasis on phenomena associated to moderate eruptions, as well as on volcano-tectonic earthquakes and landslides, which in some cases, as in El Hierro, may be more destructive than an eruption itself. As part of the Volcanic Alert System, we introduce here the Volcanic Activity Level which continuously applies a routine analysis of monitoring data (particularly seismic and deformation data) to detect data trend changes or monitoring network failures. The data trend changes are quantified according to the Failure Forecast Method (FFM). When data changes and/or malfunctions are detected, by an automated watchdog, warnings are automatically issued to the Monitoring Scientific Team. Changes in the data patterns are then translated by the Monitoring Scientific Team into a simple Volcanic Activity Level, that is easy to use and understand by the scientists and technicians in charge for the technical management of the unrest. The main feature of the Volcanic Activity Level is its objectivity, as it does not depend on expert opinions, which are left to the Scientific Committee, and its capabilities for early detection of precursors. As a consequence of the El Hierro

  9. Comparing Sociodemographic Factors Associated with Disability Between Immigrants and the Chilean-Born: Are There Different Stories to Tell?

    Directory of Open Access Journals (Sweden)

    Baltica Cabieses

    2012-12-01

    Full Text Available This study explored a range of sociodemographic factors associated with disability among international immigrants in Chile, and compared them to the Chilean-born. Secondary data analysis of the Chilean population-based survey CASEN-2006 was conducted (268,873 participants. Main health outcomes: any disability and six different types of disability: visual, hearing, learning, physical, psychiatric and speaking (binary outcomes. Sociodemographic variables: Demographic factors (age, sex, marital status, urban/rural, ethnicity, socioeconomic status (SES: income, education, employment status, and an integrated indicator combining the SES measures through cluster analysis for the immigrant population, material factors (overcrowding, sanitation, housing quality and migration related (country of origin and length of stay. Immigrants reported a significantly lower prevalence of any disability (3.55%, visual (1.00% and physical disability (0.38%. Factors associated with any disability among immigrants were age, low SES or over 20 years duration of residence in Chile; while a range of sociodemographic factors were associated with disability in the Chilean-born. Conditional regression models by age group varied between populations, but SES remained significantly associated with disability across immigrants and the Chilean-born. However, there are no similar patterns of factors associated to different types of disability between the populations under study. Factors associated with disability varied between populations under study, but SES showed a consistent association with any disability in immigrants and the Chilean-born. Types of disability showed different patterns of factors associated to them between populations, which suggest the great complexity of underlying mechanisms related to disability in Chile.

  10. Post-fire soil hydrology, water erosion and restoration strategies in Andosols: a review of evidence from the Canary Islands (Spain)

    OpenAIRE

    Neris J; Santamarta JC; Doerr SH; Prieto F; Agulló-Pérez J; García-Villegas P

    2016-01-01

    Andosols are the most characteristic soils of volcanic regions such as the forested, fire-prone, hillslopes of the mountainous Canary Islands (Spain). Due to their volcanic nature, these soils have traditionally been considered highly resistant to water erosion processes in undisturbed conditions, but are also highly susceptible to environmental disturbances. In addition, volcanic terrains often underlie heavily-populated, steep areas where torrential rains are frequent, increasing the threat...

  11. Labile carbon pools and biological activity in volcanic soils of the Canary Islands Fracciones de carbono orgánico lábil y actividad biológica en suelos de origen volcánico de las Islas Canarias Frações de carbono orgânico lábil e actividade biológica em solos de origem vulcânica das Ilhas Canárias

    Directory of Open Access Journals (Sweden)

    Cecilia María Armas Herrera

    2013-03-01

    Full Text Available It is important to assess the mineralisation of soil organic carbon (SOC to predict the short-term response of biosphere carbon reservoirs to changing environmental conditions. We investigated the labile (easily-mineralisable SOC in volcanic soils, where the bioavailability of SOC is typically affected by physico-chemical stabilisation mechanisms that are characteristic of these soils. Ten soils were selected that represent the most typical soil types (mainly Andosols and natural habitats (xerophytic scrubland, laurel forest and pine forest in the Canary Islands, a volcanic archipelago. Over two years we measured several physico-chemical SOC fractions with different degrees of bioavailability: water-soluble carbon in fresh soil samples (WSC and in the saturated extract (WSCse, hot water-extractable carbon (HWC, potassium sulphate-extractable carbon (PSC, microbial biomass carbon (MBC, particulate organic carbon (POC, humic substances carbon (HSC, and total organic carbon (TOC, and performed CO2 emission incubation assays. We related these measurements to the potential C inputs of plant litter and roots and to the activity of certain hydrolytic enzymes (CM-cellulase, ?-D-glucosidase, and dehydrogenase that are involved in carbon turnover. In vitro carbon mineralisation measurements from short assays (ten days were fitted with simple first-order kinetics to investigate SOC. This procedure was simple and allowed us to obtain estimates both for potentially mineralisable SOC and for the heterogeneity of the substrates that were consumed during incubation. The investigated volcanic soils had large labile SOC concentrations in which simple carbohydrates predominated and that were mainly derived from roots and aboveground non-woody residues. Among the analysed physico-chemical SOC fractions, HWC (3.1 g kg-1 on average at 0-30 cm depth in Andosols was the most correlated with C0 (1.2 g kg-1 and therefore best represents potentially mineralisable SOC. PSC

  12. Role of volcanism in climate and evolution

    Energy Technology Data Exchange (ETDEWEB)

    Axelrod, D.I.

    1981-01-01

    Several major episodes of Tertiary explosive volcanism coincided with sharply lowered temperature as inferred from oxygen-isotope composition of foraminiferal tests in deep-sea cores. At these times, fossil floras in the western interior recorded significant changes. Reductions in taxa that required warmth occurred early in the Paleogene. Later, taxa that demand ample summer rain were reduced during a progressive change reflecting growth of the subtropic high. Other ecosystem changes that appear to have responded to volcanically induced climatic modifications include tachytely in Equidae (12 to 10 m.y. B.P.), rapid evolution of grasses (7 to 5 m.y. B.P.), evolution of marine mammals, and plankton flucuations. Although Lake Cretaceous extinctions commenced as epeiric seas retreated, the pulses of sharply lowered temperature induced by explosive volcanism, together with widespread falls of volcanic ash, may have led to extinction of dinosaurs, ammonites, cycadeoids, and other Cretaceous taxa. earlier, as Pangaea was assembled, Permian extinctions resulted not only from the elimination of oceans, epeiric seas, and shorelines, and the spread of more-continental climates, bu also from the climatic effects of major pulses of global volcanism and Gondwana glaciation.

  13. Volcanic iodine monoxide observed from satellite

    Science.gov (United States)

    Schönhardt, Anja; Richter, Andreas; Theys, Nicolas; Burrows, John P.

    2016-04-01

    Halogen species are injected into the atmosphere by volcanic eruptions. Previous studies have reported observations of chlorine and bromine oxides in volcanic plumes. These emissions have a significant impact on the chemistry within the plume as well as on upper troposphere and lower stratosphere composition, e.g. through ozone depletion. Volcanic halogen oxides have been observed from different platforms, from ground, aircraft and from satellite. The present study reports on satellite observations of iodine monoxide, IO, following the eruption of the Kasatochi volcano, Alaska, in August 2008. Satellite measurements from the SCIAMACHY sensor onboard ENVISAT are used. In addition, the volcanic IO plume is also retrieved from GOME-2 / MetOP-A measurements. Largest IO column amounts reach up to more than 4×1013 molec/cm2, the results from both instruments being consistent. The IO plume has a very similar shape as the BrO plume and is observed for several days following the eruption. The present observations are the first evidence that besides chlorine and bromine oxides also iodine oxides can be emitted by volcanic eruptions. This has important implications for atmospheric composition and background iodine levels. Together with the simultaneous observations of BrO and SO2, iodine monoxide columns can possibly provide insights into the composition of the magma.

  14. Volcanic effects on climate: revisiting the mechanisms

    Directory of Open Access Journals (Sweden)

    H.-F. Graf

    2007-03-01

    Full Text Available The characteristics of planetary wave energy propagation are being compared based on NCEP reanalysis data from 1958 to 2002 between boreal winters after strong volcanic eruptions, non-volcanic winters and episodes of strong polar vortex lasting at least 30 days. It shows that in the volcanically disturbed winters much more planetary wave energy is produced in the troposphere, passes through the lowermost stratosphere and enters the upper stratosphere than in any other times. This is contradicting earlier interpretations and model simulations. Possibly the observed El Ninos coinciding with the three significant eruptions in the second half of the 20th century contributed to the planetary wave energy. In order to produce the observed robust climate anomaly patterns in the lower troposphere, these planetary waves are suggested to be reflected near the stratopause instead of breaking. While a strong polar vortex is observed after volcanic eruptions in the stratosphere and in the troposphere, specific episodes of strong polar vortex regime exhibit much stronger anomalies and different dynamics. Hence it is suggested that the climate effects of volcanic eruptions are not being explained by the excitation of inherent zonal mean variability modes such as Strong Polar Vortex or Northern Annular Mode, but rather is another mode that possibly reflects upon the North Atlantic Oscillation.

  15. Volcanic effects on climate: revisiting the mechanisms

    Directory of Open Access Journals (Sweden)

    H.-F. Graf

    2007-08-01

    Full Text Available The characteristics of planetary wave energy propagation are being compared based on NCEP reanalysis data from 1958 to 2002 between boreal winters after strong volcanic eruptions, non-volcanic winters and episodes of strong polar vortex lasting at least 30 days. It shows that in the volcanically disturbed winters much more planetary wave energy is produced in the troposphere, passes through the lowermost stratosphere and enters the upper stratosphere than in any other times. This is contradicting earlier interpretations and model simulations. Possibly the observed El Ninos coinciding with the three significant eruptions in the second half of the 20th century contributed to the planetary wave energy. In order to produce the observed robust climate anomaly patterns in the lower troposphere, these planetary waves are suggested to be reflected near the stratopause instead of breaking. While a strong polar vortex is observed after volcanic eruptions in the stratosphere and in the troposphere, specific episodes of strong polar vortex regime exhibit much stronger anomalies and different dynamics. Hence it is suggested that the climate effects of volcanic eruptions are not being explained by the excitation of inherent zonal mean variability modes such as Strong Polar Vortex or Northern Annular Mode, but rather is another mode that possibly reflects upon the North Atlantic Oscillation.

  16. Relationship between water quality of deep-groundwater and geology in non-volcanic areas in Japan

    International Nuclear Information System (INIS)

    Geochemical characteristics in groundwater such as groundwater chemistry and physicochemical parameters are affected by their source and the interaction with rocks and minerals. We observed the relationships between groundwater chemistry of the deep-groundwater and the geology in non-volcanic areas in Japan using about 9300 of deep-groundwater data. A Geographical Information System (GIS) was used to extract data in non-volcanic areas and numbers of water data are about 5200. The data were further classified into four types of geology (sedimentary rock, accretionary complex, volcanic rock and plutonic rock). The pH, temperature and major ion concentrations among deep-groundwaters in each geology have been statistically analysed. Result shows that the total cation concentration of deep-groundwaters are significantly different between geology, and the average values are decreased in the order of the sedimentary rock (66.7 meq l-1), volcanic rock (43.0 meq l-1), accretionary complex (24.6 meq l-1), and plutonic rock (11.0 meq l-1). The average pH does not show the major difference between geology whereas the highest average temperature is found in volcanic rock. In addition, the all four major cations (Na, K, Mg, and Ca) show the highest average concentrations in sedimentary rock, within the highest average concentrations of major anions for Cl, SO4, and HCO3 are found in sedimentary rock, volcanic rock and accretionary complex, respectively, indicating the difference of the influence on the anions varied with geology. The distribution of deep-groundwater that are dominated by each major anions implied that SO4-type groundwater in volcanic rocks are formed by the influence of Neogene volcanic rock (Green tuff). In addition, HCO3-type groundwater in accretionary complex found from Kinki to Shikoku regions are formed by the addition of CO2 gases supplying not only from surface soil and carbonate minerals but from deep underground. (author)

  17. Steep spatial gradients of volcanic and marine sulfur in Hawaiian rainfall and ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Bern, Carleton R., E-mail: cbern@usgs.gov [U.S. Geological Survey, Denver Federal Center, Denver, CO 80225 (United States); Department of Geography University of California, Santa Barbara, CA 93106-4060 (United States); Chadwick, Oliver A. [Department of Geography University of California, Santa Barbara, CA 93106-4060 (United States); Kendall, Carol [U.S. Geological Survey, Menlo Park, CA (United States); Pribil, Michael J. [U.S. Geological Survey, Denver Federal Center, Denver, CO 80225 (United States)

    2015-05-01

    Sulfur, a nutrient required by terrestrial ecosystems, is likely to be regulated by atmospheric processes in well-drained, upland settings because of its low concentration in most bedrock and generally poor retention by inorganic reactions within soils. Environmental controls on sulfur sources in unpolluted ecosystems have seldom been investigated in detail, even though the possibility of sulfur limiting primary production is much greater where atmospheric deposition of anthropogenic sulfur is low. Here we measure sulfur isotopic compositions of soils, vegetation and bulk atmospheric deposition from the Hawaiian Islands for the purpose of tracing sources of ecosystem sulfur. Hawaiian lava has a mantle-derived sulfur isotopic composition (δ{sup 34}S VCDT) of − 0.8‰. Bulk deposition on the island of Maui had a δ{sup 34}S VCDT that varied temporally, spanned a range from + 8.2 to + 19.7‰, and reflected isotopic mixing from three sources: sea-salt (+ 21.1‰), marine biogenic emissions (+ 15.6‰), and volcanic emissions from active vents on Kilauea Volcano (+ 0.8‰). A straightforward, weathering-driven transition in ecosystem sulfur sources could be interpreted in the shift from relatively low (0.0 to + 2.7‰) to relatively high (+ 17.8 to + 19.3‰) soil δ{sup 34}S values along a 0.3 to 4100 ka soil age-gradient, and similar patterns in associated vegetation. However, sub-kilometer scale spatial variation in soil sulfur isotopic composition was found along soil transects assumed by age and mass balance to be dominated by atmospheric sulfur inputs. Soil sulfur isotopic compositions ranged from + 8.1 to + 20.3‰ and generally decreased with increasing elevation (0–2000 m), distance from the coast (0–12 km), and annual rainfall (180–5000 mm). Such trends reflect the spatial variation in marine versus volcanic inputs from atmospheric deposition. Broadly, these results illustrate how the sources and magnitude of atmospheric deposition can exert controls

  18. Volcanic evolution of the South Sandwich volcanic arc, South Atlantic, from multibeam bathymetry

    Science.gov (United States)

    Leat, Philip T.; Day, Simon J.; Tate, Alex J.; Martin, Tara J.; Owen, Matthew J.; Tappin, David R.

    2013-09-01

    New multibeam bathymetry data are presented for the South Sandwich intra-oceanic arc which occupies the small Sandwich plate in the South Atlantic, and is widely considered to be a simple end-member in the range of intra-oceanic arc types. The images show for the first time the distribution of submarine volcanic, tectonic and erosional-depositional features along the whole length of the 540 km long volcanic arc, allowing systematic investigation of along-arc variations. The data confirm that the volcanic arc has a simple structure composed of large volcanoes which form a well-defined volcanic front, but with three parallel cross-cutting seamount chains extending 38-60 km from near the volcanic front into the rear-arc. There is no evidence for intra-arc rifting or extinct volcanic lines. Topographic evidence for faulting is generally absent, except near the northern and southern plate boundaries. Most of the volcanic arc appears to be built on ocean crust formed at the associated back-arc spreading centre, as previously proposed from magnetic data, but the southern part of the arc appears to be underlain by older arc or continental crust whose west-facing rifted margin facing the back-arc basin is defined by the new bathymetry. The new survey shows nine main volcanic edifices along the volcanic front and ca. 20 main seamounts. The main volcanoes form largely glaciated islands with summits 3.0-3.5 km above base levels which are 2500-3000 m deep in the north and shallower at 2000-2500 m deep in the south. Some of the component seamounts are interpreted to have been active since the last glacial maximum, and so are approximately contemporaneous with the volcanic front volcanism. Seven calderas, all either submarine or ice-filled, have been identified: Adventure volcano, a newly discovered submarine volcanic front caldera volcano is described for the first time. All but one of the calderas are situated on summits of large volcanoes in the southern part of the arc, and

  19. Composition and pools of humus in natural and agrogenic soils of the Kamchatka Peninsula

    Science.gov (United States)

    Kiseleva, I. V.; Purtova, L. N.; Kostenkov, N. M.

    2016-06-01

    Differentiation of Kamchatka soils with respect to the composition and pools of humus is discussed. Very low and low pools of humus of the fulvate type are typical of the ocherous and stratified ocherous volcanic soils of the eastern coastal zone and the Central Kamchatka Depression. Ocherous volcanic soils of the Western Kamchatka Lowland are characterized by the low and moderate pools of the humate-fulvate humus. Agrogenic soils are characterized by the higher pools of humus in the upper 20 cm in comparison with their natural analogues, which is largely related to changes in the physical properties of the soils under the impact of tillage.

  20. Characterization of early microbial communities on volcanic deposits along a vegetation gradient on the island of Miyake, Japan.

    Science.gov (United States)

    Guo, Yong; Fujimura, Reiko; Sato, Yoshinori; Suda, Wataru; Kim, Seok-won; Oshima, Kenshiro; Hattori, Masahira; Kamijo, Takashi; Narisawa, Kazuhiko; Ohta, Hiroyuki

    2014-01-01

    The 2000 eruption of Mount Oyama on the island of Miyake (Miyake-jima) created a unique opportunity to study the early ecosystem development on newly exposed terrestrial substrates. In this study, bacterial and fungal communities on 9- and 11-year-old volcanic deposits at poorly to fully vegetation-recovered sites in Miyake-jima, Japan, were characterized by conventional culture-based methods and pyrosequencing of 16S rRNA and 18S rRNA genes. Despite the differences in the vegetation cover, the upper volcanic deposit layer samples displayed low among-site variation for chemical properties (pH, total organic carbon, and total nitrogen) and microbial population densities (total direct count and culturable count). Statistical analyses of pyrosequencing data revealed that the microbial communities of volcanic deposit samples were phylogenetically diverse, in spite of very low-carbon environmental conditions, and their diversity was comparable to that in the lower soil layer (buried soil) samples. Comparing with the microbial communities in buried soil, the volcanic deposit communities were characterized by the presence of Betaproteobacteria and Gammaproteobacteria as the main bacterial class, Deinococcus- Thermus as the minor bacterial phyla, and Ascomycota as the major fungal phyla. Multivariate analysis revealed that several bacterial families and fungal classes correlated positively or negatively with plant species. PMID:24463576

  1. National volcanic ash operations plan for aviation

    Science.gov (United States)

    ,; ,

    2007-01-01

    The National Aviation Weather Program Strategic Plan (1997) and the National Aviation Weather Initiatives (1999) both identified volcanic ash as a high-priority informational need to aviation services. The risk to aviation from airborne volcanic ash is known and includes degraded engine performance (including flameout), loss of visibility, failure of critical navigational and operational instruments, and, in the worse case, loss of life. The immediate costs for aircraft encountering a dense plume are potentially major—damages up to $80 million have occurred to a single aircraft. Aircraft encountering less dense volcanic ash clouds can incur longer-term costs due to increased maintenance of engines and external surfaces. The overall goal, as stated in the Initiatives, is to eliminate encounters with ash that could degrade the in-flight safety of aircrews and passengers and cause damage to the aircraft. This goal can be accomplished by improving the ability to detect, track, and forecast hazardous ash clouds and to provide adequate warnings to the aviation community on the present and future location of the cloud. To reach this goal, the National Aviation Weather Program established three objectives: (1) prevention of accidental encounters with hazardous clouds; (2) reduction of air traffic delays, diversions, or evasive actions when hazardous clouds are present; and (3) the development of a single, worldwide standard for exchange of information on airborne hazardous materials. To that end, over the last several years, based on numerous documents (including an OFCMsponsored comprehensive study on aviation training and an update of Aviation Weather Programs/Projects), user forums, and two International Conferences on Volcanic Ash and Aviation Safety (1992 and 2004), the Working Group for Volcanic Ash (WG/VA), under the OFCM-sponsored Committee for Aviation Services and Research, developed the National Volcanic Ash Operations Plan for Aviation and Support of the

  2. Measurement of radioactivity in volcanic products

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Jun

    1988-10-01

    Radioactivity in volcanic products was measured for obtaining new knowledge about volcano. A distribution map of /sup 2//sup 2//sup 8/Ra//sup 2//sup 2//sup 6/Ra in the volcanic products of Japanese Islands volcanic front was prepared. From the map, it was understood that only Izu-Mariana Arc was different from other series of vocanos. Concerning Volcano Sakurajima, /sup 2//sup 2//sup 2/Rn//sup 2//sup 2//sup 0/Rn ratio in the pumice produced by the eruption was measured for studying its change with days after creation. Regarding the lava of Miyake Island, change of /sup 2//sup 1//sup 4/Bi with time was measured. 3 figures.

  3. The attitude of the Chilean newspaper "El Mercurio" towards the main economic policies of the Popular Unity government of Salvador Allende (1970 - 1973).

    OpenAIRE

    2002-01-01

    Resumé of History major: “The attitude of the Chilean newspaper ‘El Mercurio’ towards the main economic policies of the Popular Unity government of Salvador Allende (1970-73)” By Paul Francis Llewellyn Department of History University of Oslo, Norway Autumn 2002 Introduction This investigation will show in what manner the conservative daily newspaper El Mercurio presented the main economic policies of the Chilean left-wing Popular Unity (UP) government during its ter...

  4. Free education! A 'live' report from the Chilean student movement, 2011-2014 - reform or revolution? [A political sociology for action

    OpenAIRE

    Simbuerger, Elisabeth; Neary, Mike

    2015-01-01

    This paper provides a report on the Chilean student movement, 2011 – 2014, from the perspective of the students themselves, based on the research question: are the student protesters for reform or revolution? The research was done just before the November 2013 Chilean Presidential and Parliamentary elections using ‘live methods’ (Back and Puwar 2012). The live methods used here include an ethnographic report from a student protest march in downtown Santiago, Chile, illustrated with a Twitt...

  5. Seismo-volcanic sources on Stromboli volcano

    Directory of Open Access Journals (Sweden)

    R. Luckett

    1996-06-01

    Full Text Available A detailed analysis of broadband seismic recordings leads to models of eruption mechanisms for Strombolian activity. The data used comprise signals from arrays of nine three-component seismometers and video recordings of visual eruptive activity with precise time reference. As a major tool particle motion analysis is used to locate the seismo-volcanic sources. Here, a surface correction is employed to account for the effects of the steep slopes of the volcanic edifice. After careful filtering of the data single seismic phases can be separated and linked to corresponding eruptive features.

  6. Volcanic Eruptions and Climate: Outstanding Research Issues

    Science.gov (United States)

    Robock, Alan

    2016-04-01

    Large volcanic eruptions inject sulfur gases into the stratosphere, which convert to sulfate aerosols with an e-folding residence time of about one year. The radiative and chemical effects of this aerosol cloud produce responses in the climate system. Based on observations after major eruptions of the past and experiments with numerical models of the climate system, we understand much about their climatic impact, but there are also a number of unanswered questions. Volcanic eruptions produce global cooling, and are an important natural cause of interannual, interdecadal, and even centennial-scale climate change. One of the most interesting volcanic effects is the "winter warming" of Northern Hemisphere continents following major tropical eruptions. During the winter in the Northern Hemisphere following every large tropical eruption of the past century, surface air temperatures over North America, Europe, and East Asia were warmer than normal, while they were colder over Greenland and the Middle East. This pattern and the coincident atmospheric circulation correspond to the positive phase of the Arctic Oscillation. While this response is observed after recent major eruptions, most state-of-the-art climate models have trouble simulating winter warming. Why? High latitude eruptions in the Northern Hemisphere, while also producing global cooling, do not have the same impact on atmospheric dynamics. Both tropical and high latitude eruptions can weaken the Indian and African summer monsoon, and the effects can be seen in past records of flow in the Nile and Niger Rivers. Since the Mt. Pinatubo eruption in the Philippines in 1991, there have been no large eruptions that affected climate, but the cumulative effects of small eruptions over the past decade have had a small effect on global temperature trends. Some important outstanding research questions include: How much seasonal, annual, and decadal predictability is possible following a large volcanic eruption? Do

  7. Emplacement Scenarios for Volcanic Domes on Venus

    Science.gov (United States)

    Glaze, Lori S.; Baloga, Steve M.; Stofan, Ellen R.

    2012-01-01

    One key to understanding the history of resurfacing on Venus is better constraints on the emplacement timescales for the range of volcanic features visible on the surface. A figure shows a Magellan radar image and topography for a putative lava dome on Venus. 175 such domes have been identified with diameters ranging from 19 - 94 km, and estimated thicknesses as great as 4 km. These domes are thought to be volcanic in origin and to have formed by the flow of viscous fluid (i.e., lava) on the surface.

  8. Constraining the onset of flood volcanism in Isle of Skye Lava Field, British Paleogene Volcanic Province

    Science.gov (United States)

    Angkasa, Syahreza; Jerram, Dougal. A.; Svensen, Henrik; Millet, John M.; Taylor, Ross; Planke, Sverre

    2016-04-01

    In order to constrain eruption styles at the onset of flood volcanism, field observations were undertaken on basal sections of the Isle of Skye Lava Field, British Paleogene Volcanic Province. This study investigates three specific sections; Camus Ban, Neist Point and Soay Sound which sample a large area about 1500 km2 and can be used to help explain the variability in palaeo-environments at the onset of flood volcanism. Petrological analysis is coupled with petrophysical lab data and photogrammetry data to create detailed facies models for the different styles of initiating flood basalt volcanism. Photogrammetry is used to create Ortho-rectified 3D models which, along with photomontage images, allow detailed geological observations to be mapped spatially. Petrographic analyses are combined with petrophysical lab data to identify key textural variation, mineral compositions and physical properties of the volcanic rocks emplaced during the initial eruptions. Volcanism initiated with effusive eruptions in either subaerial or subaqueous environments resulting in tuff/hyaloclastite materials or lava flow facies lying directly on the older Mesozoic strata. Volcanic facies indicative of lava-water interactions vary significantly in thickness between different sections suggesting a strong accommodation space control on the style of volcanism. Camus Ban shows hyaloclastite deposits with a thickness of 25m, whereas the Soay Sound area has tuffaceous sediments of under 0.1m in thickness. Subaerial lavas overly these variable deposits in all studied areas. The flood basalt eruptions took place in mixed wet and dry environments with some significant locally developed water bodies (e.g. Camus Ban). More explosive eruptions were promoted in some cases by interaction of lavas with these water bodies and possibly by local interaction with water - saturated sediments. We record key examples of how palaeotopography imparts a primary control on the style of volcanism during the

  9. Latin American electricity markets and renewable energy sources: The Argentinean and Chilean cases

    Energy Technology Data Exchange (ETDEWEB)

    Guzowski, C. [Department of Economy, Universidad Nacional del Sur, 12 de Octubre y San Juan, 8000 Bahia Blanca (Argentina); Recalde, M. [CONICET - Department of Economy, Universidad Nacional del Sur, 12 de Octubre y San Juan, 8000 Bahia Blanca (Argentina)

    2010-06-15

    From the mid eighties on, most of Latin American Countries reformed their energy systems. The impact of these reforms over electricity markets was different in each case. However, in the majority of these cases there was a shift to private participation, instead of State, and a convergence of electricity systems to hydro and thermal technologies. This is the case of Argentina and Chile. In this context, the aim of this paper is to discuss the current situation of renewable energies in Chilean and Argentinean electric markets and the potential to increase their share in total energy supply. To this purpose, we firstly study electricity deregulation process and its current situation. Secondly, we analyze renewable energy share in these electricity systems comparatively to worldwide situation. Finally, we briefly present the policy instruments used in each country. (author)

  10. [The absence of stewardship in the Chilean health authority after the 2004 health reform].

    Science.gov (United States)

    Herrera, Tania; Sánchez, Sergio

    2014-01-01

    Stewardship is the most important political function of a health system. It is a government responsibility carried out by the health authority. Among other dimensions, it is also a meta-function that includes conduction and regulation. The Health Authority and Management Act, which came about from the health reform of 2004, separated the functions of service provision and stewardship with the aim of strengthening the role of the health authority. However, the current structure of the health system contains overlapping functions between the different entities that leads to lack of coordination and inconsistencies, and a greater weight on individual health actions at the expense of collective ones. Consequently, a properly funded national health strategy to improve the health of the population is missing. Additionally, the components of citizen participation and governance are weak. It is necessary, therefore, to revisit the Chilean health structure in order to develop one that truly enables the exercise of the health authority’s stewardship role.

  11. Preliminary Psychometric examination of the Davidson Trauma Scale: A study on chileans adolescent

    Directory of Open Access Journals (Sweden)

    Cristobal Guerra

    2013-12-01

    Full Text Available Davidson Trauma Scale (DTS measures the frequency and severity of the posttraumatic Stress Disorder pTSD. Since chile has limited data about validity and reliability of instruments to measure pTSD, this study evaluated psychometric properties of the scale in a sample of 130 adolescents between 13 and 18 years (M= 15,78; DT= 1,40. Some of them were traumatized patients and others were from general population. They answered the DTS, a depression and an anxiety scale. The scale obtained adequate internal consistency scores, showed convergent validity (DTS score was associated moderately, directly and significantly with depression and anxiety scores, and discriminated between clinical sample and general population. DTS seems to be a valid and reliable instrument in chilean adolescents.

  12. Crustacean zooplankton species richness in Chilean lakes and ponds (23°-51°S

    Directory of Open Access Journals (Sweden)

    Patricio De los Ríos-Escalante

    2013-07-01

    Full Text Available Chilean inland-water ecosystems are characterized by their low species-level biodiversity. This study analyses available data on surface area, maximum depth, conductivity, chlorophyll-α concentration, and zooplankton crustacean species number in lakes and ponds between 23° and 51°S. The study uses multiple regression analysis to identify the potential factors affecting the species number. The partial correlation analysis indicated a direct significant correlation between chlorophyll-α concentration and species number, whereas the multiple regression analysis indicated a direct significant response of species number to latitude and chlorophyll-α concentration. These results agree with findings from comparable ecosystems in Argentina and New Zealand.

  13. My child and his siblings: women’s experience of first maternity in Chilean stepfamilies

    Directory of Open Access Journals (Sweden)

    J. Carola Pérez Ewert

    2011-05-01

    Full Text Available This qualitative study shows the perception of a group of Chilean women aged between 29 and 39 years regarding their experience of having their first child when they are members of a simple stepfamily. Sixteen women, whose partners maintain active contact with their child(ren born in previous relationships were interviewed. Results confirm the existence of a process of “becoming a mother” and its course depends on stepchildren’s presence. In addition our more relevant findings show that the specific topics of fears and motivations of having a child depend on the particular stepfamilycontext, and women’s experiences is that this process vary according to the perceived quality of stepmother/stepchildren relationships.

  14. Ultrasound application for MOE determination of some Chilean species of wood

    Science.gov (United States)

    Baradit, Erik; Fuentealba, Cecillia; San Martin, Alex

    1999-02-01

    In this work a preliminary study of an ultrasound application, as a non destructive technique, for the evaluation of some chilean wood species is shown. By means of this technique the elasticity moduli (MOE) along the fibers for different positions of the samples with respect to the pith and different moisture contents are determined. At the same time the wood anisotropy properties are evaluated as the ratio between velocities along the main directions of the tree. In general, the obtained results show a high correlations between the MOE obtained by mechanic and ultrasound essays while the anisotropy values correspond mainly to the expected results. Finally, it is considered that the application of this technique as a complement to other non destructive techniques conform an excellent tool for evaluation and quality control of wood products.

  15. Experience and new challenges in the Chilean generation and transmission sector

    International Nuclear Information System (INIS)

    The Chilean electrical sector was deregulated in 1982, where unbundling was applied, and generation competition and marginal costing were introduced. Description of the main features of the generation market and system operation is presented, followed by a synthesis of the main achievements and difficulties experienced in the practical application. The experience with the troubles faced in the reformed power sector after 18 years is used to look at the possible advantages of the second stage of deregulation. The challenges of a new legislation, where the system is expected to join the second generation of deregulation are discussed. Advantage and risks of opening the energy market with a bidding system separate from ancillary service market are analysed. The experience with the troubles faced in the reformed power sector after 18 years is used to look at the possible advantages of the second stage of deregulation. (author)

  16. [Quality control in Medicine. Position of the Chilean Academy of Medicine].

    Science.gov (United States)

    Goic, A; Segovia, S

    2001-07-01

    In the last two decades, important changes in medical training and care have occurred in Chile. The number of medical schools has been doubled, exceeding the national availability of professors and qualified training fields. The quality assessment and accreditation of medical training and care is insufficient in Chile. A National Autonomous Corporation of Certification of Medical Specialties, has certified more than 4,000 physicians in 44 specialties. The Chilean Association of Faculties of Medicine has accredited training centers during the last four decades. The National Commission of Undergraduate Training Accreditation, has developed a voluntary system for medical school accreditation. The Academy supports these strategies and considers that accreditation does not threaten institutions or individuals. It is rather a mechanism that identifies strengths and weaknesses of institutions and programs. This will finally result in better quality in medical training and patient care.

  17. A new species of Heleobia (Caenogastropoda: Cochliopidae) from the Chilean Altiplano.

    Science.gov (United States)

    Collado, Gonzalo A; Valladares, Moisés A; Méndez, Marco A

    2016-07-11

    Cochliopidae Tryon, 1866 is a diverse family of caenogastropods that lives in a wide variety of aquatic habitats primarily in the New World (Hershler &Thompson 1992). In Chile, the species of the group have been traditionally assigned to the genus Littoridina Souleyet, 1852 using conchological characters (Biese 1944, 1947; Stuardo, 1961; Valdovinos 2006) but according to anatomical studies and phylogenetic analysis the majority of them have been reassigned to the genus Heleobia Stimpson, 1865 (Hershler & Thompson 1992; Collado et al. 2011a; Kroll et al. 2012; Collado et al. 2013; Collado et al. 2016). Here we formally describe a new species of the genus Heleobia from Spring 1 in the Carcote saltpan, Chilean Altiplano, based on molecular and morphological characters. Snails from this locality were previously shown to be distinct based on DNA sequences (Collado et al. 2013; Collado et al. 2016).

  18. Chilean jagged lobster, Projasus bahamondei, in the southeastern Pacific Ocean: current state of knowledge

    Directory of Open Access Journals (Sweden)

    Patricio M Arana

    2014-03-01

    Full Text Available The Chilean jagged lobster (Projasus bahamondei is a deep-water crustacean (175-550 m occurring in certain areas of the southeastern Pacific Ocean, including the Nazca Ridge, Desventuradas Islands, the Juan Fernandez archipelago and ridge, and the continental slope off the central coast of Chile. This review describes the taxonomic status, geographical and bathymetric distribution, some biological aspects and habitat characteristics of this species. Additionally, both artisanal and industrial exploitation attempts made within the region are detailed, as well as fishing operation results, chemical composition, different elaboration procedures and the destination of the catch. The main objectives of this review are to contribute to the knowledge of P. bahamondei as a component of the deep-sea ecosystem and to highlight its importance as a potential fishery resource.

  19. Genetic diversity of Chilean and Brazilian alstroemeria species assessed by AFLP analysis.

    Science.gov (United States)

    Han, T H; de Jeu, M; van Eck, H; Jacobsen, E

    2000-05-01

    One to three accessions of 22 Alstroemeria species, an interspecific hybrid (A. aurea x A. inodora), and single accessions of Bomarea salsilla and Leontochir ovallei were evaluated using the AFLP-marker technique to estimate the genetic diversity within the genus Alstroemeria. Three primer combinations generated 716 markers and discriminated all Alstroemeria species. The dendrogram inferred from the AFLP fingerprints supported the conjecture of the generic separation of the Chilean and Brazilian Alstroemeria species. The principal co-ordinate plot showed the separate allocation of the A. ligtu group and the allocation of A. aurea, which has a wide range of geographical distribution and genetic variation, in the middle of other Alstroemeria species. The genetic distances, based on AFLP markers, determined the genomic contribution of the parents to the interspecific hybrid. PMID:10849081

  20. Trematodes indicate animal biodiversity in the chilean intertidal and Lake Tanganyika

    Science.gov (United States)

    Hechinger, R.F.; Lafferty, K.D.; Kuris, A.M.

    2008-01-01

    Trematode communities in populations of estuarine snails can reflect surrounding animal diversity, abundance, and trophic interactions. We know less about the potential for trematodes to serve as bioindicators in other habitats. Here, we reanalyze data from 2 published studies concerning trematodes, 1 in the Chilean rocky intertidal zone and the other from the East African rift lake, Lake Tanganyika. Our analyses indicate that trematodes are more common in protected areas and that in both habitats they are directly and positively related to surrounding host abundance. This further supports the notion that trematodes in first intermediate hosts can serve as bioindicators of the condition of free-living animal communities in diverse ecosystems. ?? American Society of Parasitologists 2008.

  1. Policy Positions in the Chilean Senate: An Analysis of Coauthorship and Roll Call Data

    Directory of Open Access Journals (Sweden)

    Eduardo Alemán

    2008-12-01

    Full Text Available This paper examines the policy positions of Chilean senators. The empirical analysis focuses on two different legislative activities: voting and coauthoring bills. The roll call analysis evaluates the degree to which coalitions act as cohesive policy teams on the floor of Congress, whether parties’ positions match conventional ideological rankings, and the dimensionality of voting decisions. The coauthorship analysis provides alternative ideal points to examine similar questions. The findings of the voting analysis reveal a rather unidimensional world with two distinct clusters matching coalitional affiliation, while the analysis of coauthorship illuminates a more complex pattern of associations. Neither roll call votes nor coauthorship patterns, however, reveal substantive fissures within the governing coalition. In comparison, the opposition coalition appears more divided along partisan lines.

  2. Bifactor Modeling of the Behavior Rating Inventory of Executive Function (BRIEF) in a Chilean Sample.

    Science.gov (United States)

    Pérez-Salas, Claudia Paz; Ramos, Carlos; Oliva, Karen; Ortega, Alonso

    2016-06-01

    The Behavior Rating Inventory of Executive Functions evaluates executive functioning through the observation of students' performance in real contexts. Most psychometric studies of the scale have only tested the first-order structure, despite the hierarchical configuration of its theoretical model. A bifactor model was conducted on a normative sample of 5- to 18-year-old Chileans (M age = 11.3 years, SD = 3.7) to test a hierarchical structure of three first-order factors and an independent second-order factor. Bifactor analyses showed best fit for the proposed hierarchical structure. Findings supported a method to evaluate executive functioning models that provides a general global factor score that may complement existing indices and thus help clinicians to make better inferences. PMID:27216945

  3. Psychometric properties of the personal wellbeing index in Brazilian and Chilean adolescents including spirituality and religion

    Directory of Open Access Journals (Sweden)

    Jorge Castellá Sarriera

    2014-12-01

    Full Text Available This study compared the 7-item Personal Wellbeing Index (PWI with two other versions which include the domains "Spirituality" and "Religion", separately, in a sample of Brazilian (n = 1.047 and Chilean (n = 1.053 adolescents. A comparison of psychometric properties between the PWI versions was carried out through multigroup confirmatory factor analysis showing adequate adjustments (CFI > .95, RMSEA < .08, whereas the item spirituality presented better performance. For the analysis of the differential contribution of each domain to the notion of global satisfaction, a regression on the item Overall Life Satisfaction (OLS was applied using structural equations. It is recommended the inclusion of the item spirituality in the original scale, considering the importance of such domain in both cultures.

  4. Autoimmune pulmonary proteinosis in a Chilean teenager, a rare aetiology of interstitial lung disease.

    Science.gov (United States)

    Strickler, Alexis; Boza, Maria Lina; Koppmann, Andres; Gonzalez, Sergio

    2014-05-23

    Interstitial lung disease (ILD) is rare and encompasses a heterogeneous group of diseases, and is even rarer in children than in adults. ILDs compromise more than 100 different entities, including pulmonary alveolar proteinosis (PAP). There are many causes of PAP in children, including surfactant protein gene mutations (SFTPB, SFTPC, ABCA3, TTF-1), GMCSF receptor mutations and antigranulocyte-macrophage colony-stimulating factor autoantibodies. We report a case of a 13-year-old Chilean girl who presented with an 8-month history of progressive exercise intolerance, fatigability and diminished school performance. Physical examination revealed resting tachypnoea, a few basal bilateral inspiratory crackles, and hypoxaemia on minimal exertion. Clinical suspicion and evaluation, including international collaboration, led to the diagnosis of autoimmune PAP and specific therapy for the condition.

  5. The HLA-A*68:23 allele in the Chilean population.

    Science.gov (United States)

    Turner, E V; Dilioglou, S; Arnold, P Y; Palma, J; Rivera, G

    2014-12-01

    HLA-A*68:23, first described in 2002, has not been widely reported. The studies reported here were performed for support of a collaborative hematopoietic stem cell transplantation program at Luis Calvo Mackenna Hospital for which St. Jude Children's Research Hospital provided human leukocyte antigen (HLA) typing. Family studies performed between 2000 and 2011 included 197 patients and their immediate family members. In a total of 559 individuals, A*68:23 was confirmed by DNA sequencing in eight individuals with no known relationship to each other. A*68:23 positive individuals included six patients, along with one of their parents, and two parents whose children did not inherit A*68:23. The frequency of A*68:23 in this Chilean population is >0.0125. This HLA-A allele appears to fit the description of a well-documented allele in this population studied in Santiago, Chile. PMID:25352173

  6. Characteristics of pristine volcanic materials: Beneficial and harmful effects and their management for restoration of agroecosystem.

    Science.gov (United States)

    Anda, Markus; Suparto; Sukarman

    2016-02-01

    Eruption of Sinabung volcano in Indonesia began again in 2010 after resting for 1200 years. The volcano is daily emitting ash and pyroclastic materials since September 2013 to the present, damaging agroecosystems and costing for management restoration. The objective of the study was to assess properties and impacts of pristine volcanic material depositions on soil properties and to provide management options for restoring the affected agroecosytem. Land satellite imagery was used for field studies to observe the distribution, thickness and properties of ashfall deposition. The pristine ashfall deposits and the underlying soils were sampled for mineralogical, soluble salt, chemical, physical and toxic compound analyses. Results showed that uneven distribution of rainfall at the time of violent eruption caused the areas receiving mud ashfall developed surface encrustation, which was not occur in areas receiving dry ashfall. Ashfall damaged the agroecosytem by burning vegetation, forming surface crusts, and creating soil acidity and toxicity. X-ray diffraction (XRD) and scanning electron microscope (SEM) analyses of encrustated layer indicated the presence of gypsum and jarosite minerals. Gypsum likely acted as a cementing agent in the formation of the encrustation layer with extremely low pH (2.9) and extremely high concentrations of Al, Ca and S. Encrustation is responsible for limited water infiltration and root penetration, while the extremely high concentration of Al is responsible for crop toxicity. Mud ashfall and dry ashfall deposits also greatly changed the underlying soil properties by decreasing soil pH and cation exchange capacity and by increasing exchangeable Ca, Al, and S availability. Despite damaging vegetation in the short-term, the volcanic ashfall enriched the soil in the longer term by adding nutrients like Ca, Mg, K, Na, P, Si and S. Suggested management practices to help restore the agroecosystem after volcanic eruptions include: (i) the

  7. Characteristics of pristine volcanic materials: Beneficial and harmful effects and their management for restoration of agroecosystem.

    Science.gov (United States)

    Anda, Markus; Suparto; Sukarman

    2016-02-01

    Eruption of Sinabung volcano in Indonesia began again in 2010 after resting for 1200 years. The volcano is daily emitting ash and pyroclastic materials since September 2013 to the present, damaging agroecosystems and costing for management restoration. The objective of the study was to assess properties and impacts of pristine volcanic material depositions on soil properties and to provide management options for restoring the affected agroecosytem. Land satellite imagery was used for field studies to observe the distribution, thickness and properties of ashfall deposition. The pristine ashfall deposits and the underlying soils were sampled for mineralogical, soluble salt, chemical, physical and toxic compound analyses. Results showed that uneven distribution of rainfall at the time of violent eruption caused the areas receiving mud ashfall developed surface encrustation, which was not occur in areas receiving dry ashfall. Ashfall damaged the agroecosytem by burning vegetation, forming surface crusts, and creating soil acidity and toxicity. X-ray diffraction (XRD) and scanning electron microscope (SEM) analyses of encrustated layer indicated the presence of gypsum and jarosite minerals. Gypsum likely acted as a cementing agent in the formation of the encrustation layer with extremely low pH (2.9) and extremely high concentrations of Al, Ca and S. Encrustation is responsible for limited water infiltration and root penetration, while the extremely high concentration of Al is responsible for crop toxicity. Mud ashfall and dry ashfall deposits also greatly changed the underlying soil properties by decreasing soil pH and cation exchange capacity and by increasing exchangeable Ca, Al, and S availability. Despite damaging vegetation in the short-term, the volcanic ashfall enriched the soil in the longer term by adding nutrients like Ca, Mg, K, Na, P, Si and S. Suggested management practices to help restore the agroecosystem after volcanic eruptions include: (i) the

  8. Locking, mass flux and topographic response at convergent plate boundaries - the Chilean case

    Science.gov (United States)

    Oncken, Onno

    2016-04-01

    On the long term, convergent plate boundaries have been shown to be controlled by either accretion/underplating or by subduction erosion. Vertical surface motion is coupled to convergence rate - typically with an uplift rate of the coastal area ranging from 0 to +50% of convergence rate in accretive systems, and -20 to +30% in erosive systems. Vertical kinematics, however, are not necessarily linked to horizontal strain mode, i.e. upper plate shortening or extension, in a simple way. This range of kinematic behaviors - as well as their acceleration where forearcs collide with oceanic ridges/plateau - is well expressed along the Chilean plate margin. Towards the short end of the time scale, deformation appears to exhibit a close correlation with the frictional properties and geodetic locking at the plate interface. Corroborating analogue experiments of strain accumulation during multiple earthquake cycles, forearc deformation and uplift focus above the downdip and updip end of seismic coupling and slip and are each related to a particular stage of the seismic cycle, but with opposite trends for both domains. Similarly, barriers separating locked domains along strike appear to accumulate most upper plate faulting interseismically. Hence, locking patters are reflected in topography. From the long-term memory contained in the forearc topography the relief of the Chilean forearc seems to reflect long term stability of the observed heterogeneity of locking at the plate interface. This has fundamental implications for spatial and temporal distribution of seismic hazard. Finally, the nature of locking at the plate interface controlling the above kinematic behavior appears to be strongly controlled by the degree of fluid overpressuring at the plate interface suggesting that the hydraulic system at the interface takes a key role for the forearc response.

  9. PRESENCE OF MYCOBACTERIUM AVIUM SUBSP. PARATUBERCULOSIS IN ALPACAS (LAMA PACOS) INHABITING THE CHILEAN ALTIPLANO.

    Science.gov (United States)

    Salgado, Miguel; Sevilla, Iker; Rios, Carolina; Crossley, Jorge; Tejeda, Carlos; Manning, Elizabeth

    2016-03-01

    Mycobacterium avium subsp. paratuberculosis (MAP) is the etiologic agent of paratuberculosis. The organism causes disease in both domestically managed and wild ruminant species. South American camelids have a long, shared history with indigenous people in the Andes. Over the last few decades, increasing numbers of alpacas were exported to numerous countries outside South America. No paratuberculosis surveillance has been reported for these source herds. In this study, individual fecal samples from 85 adult alpacas were collected from six separate herds in the Chilean Altiplano. A ParaTB mycobacterial growth indicator tube (MGIT) liquid culture of each individual fecal sample, followed by real-time polymerase chain reaction (PCR) protocol was used for confirmation. DNA extracts from a subset of confirmed MAP isolates were subjected to mycobacterial interspersed repetitive units-variable number of tandem repeats (MIRU-VNTR) typing. Fifteen alpaca were fecal culture test-positive. Five false-positive culture samples were negative on PCR analysis for Mycobacterium avium subsp. avium (MAA), Mycobacterium bovis (M. bovis), and the 16 S rDNA gene. Three MAP isolates subset-tested belonged to the same MIRU-VNTR type, showing four repeats for TR292 (locus 1) in contrast to the three repeats typical of the MAP reference strain K10. The number of repeats found in the remaining loci was identical to that of the K10 strain. It is not known how nor when MAP was introduced into the alpaca population in the Chilean Altiplano. The most plausible hypothesis to explain the presence of MAP in these indigenous populations is transmission by contact with infected domestic small ruminant species that may on occasion share pastures or range with alpacas. Isolation of this mycobacterial pathogen from such a remote region suggests that MAP has found its way beyond the confines of intensively managed domestic agriculture premises.

  10. Family and parenting characteristics associated with marijuana use by Chilean adolescents

    Directory of Open Access Journals (Sweden)

    Andrew Grogan-Kaylor

    2011-03-01

    Full Text Available Cristina B Bares1, Jorge Delva2, Andrew Grogan-Kaylor2, Fernando Andrade31Curtis Research and Training Center, School of Social Work, 2School of Social Work, 3School of Education, University of Michigan, Ann Arbor, MI, USAObjective: Family involvement and several characteristics of parenting have been suggested to be protective factors for adolescent substance use. Some parenting behaviors may have stronger relationships with adolescent behavior while others may have associations with undesirable behavior among youth. Although it is generally acknowledged that families play an important role in the lives of Chilean adolescents, scant research exists on how different family and parenting factors may be associated with marijuana use and related problems in this population which has one of the highest rates of drug use in Latin America.Methods: Using logistic regression and negative binomial regression, we examined whether a large number of family and parenting variables were associated with the possibility of Chilean adolescents ever using marijuana, and with marijuana-related problems. Analyses controlled for a number of demographic and peer-related variables.Results: Controlling for other parenting and family variables, adolescent reports of parental marijuana use showed a significant and positive association with adolescent marijuana use. The multivariate models also revealed that harsh parenting by fathers was the only family variable associated with the number of marijuana-related problems youth experienced. Conclusion: Of all the family and parenting variables studied, perceptions of parental use of marijuana and harsh parenting by fathers were predictors for marijuana use, and the experience of marijuana-related problems. Prevention interventions need to continue emphasizing the critical socializing role that parental behavior plays in their children's development and potential use of marijuana.Keywords: parenting, families, adolescent

  11. Alcohol, binge drinking and associated mental health problems in young urban Chileans.

    Directory of Open Access Journals (Sweden)

    Amanda J Mason-Jones

    Full Text Available To explore the link between alcohol use, binge drinking and mental health problems in a representative sample of adolescent and young adult Chileans.Age and sex-adjusted Odds Ratios (OR for four mental wellbeing measures were estimated with separate conditional logistic regression models for adolescents aged 15-20 years, and young adults aged 21-25 years, using population-based estimates of alcohol use prevalence rates from the Chilean National Health Survey 2010.Sixty five per cent of adolescents and 85% of young adults reported drinking alcohol in the last year and of those 83% per cent of adolescents and 86% of young adults reported binge drinking in the previous month. Adolescents who reported binging alcohol were also more likely, compared to young adults, to report being always or almost always depressed (OR 12.97 [95% CI, 1.86-19.54] or to feel very anxious in the last month (OR 9.37 [1.77-19.54]. Adolescent females were more likely to report poor life satisfaction in the previous year than adolescent males (OR 8.50 [1.61-15.78], feel always or almost always depressed (OR 3.41 [1.25-9.58]. Being female was also associated with a self-reported diagnosis of depression for both age groups (adolescents, OR 4.74 [1.49-15.08] and young adults, OR 4.08 [1.65-10.05].Young people in Chile self-report a high prevalence of alcohol use, binge drinking and associated mental health problems. The harms associated with alcohol consumption need to be highlighted through evidence-based prevention programs. Health and education systems need to be strengthened to screen and support young people. Focussing on policy initiatives to limit beverage companies targeting alcohol to young people will also be needed.

  12. Fat and carbohydrates in the diet: Its metabolic contribution to obesity in Chilean women

    International Nuclear Information System (INIS)

    It has been found that children and adults in the Chilean population are getting obese in a rapidly raising proportion. There is a cohort of children less than six years old, which are regularly controlled by the Ministry of Health. From this information and studies carried out at INTA, it is known that the prevalence is raising continuously. Unfortunately, this can not be ascertained in adults where the nutritional situation is assessed only in small groups, which are not representative of the general population. The problem with adults is that the healthy population does not attend to the medical clinics unless they are already ill. The studies conducted in Chilean adults have found that >40% of low socio-economic status (SES) women are suffering from obesity. A intriguing aspect in our situation is that although sedentarism is frequent in adult women (as a possible cause of positive energy balance), their intake is based on a high proportion of carbohydrates (CHO) but not much fat (50-70 g on average). It may be suggested that the excess CHO can be converted into fat through denovo lipogenesis but this process is less important as cause of obesity in humans. A more plausible cause of this problem is likely to be related to the diet. The oxidation hierarchy of macronutrients shows that whenever CHO and fat are available, the former will be firstly oxidised. This way, fat can be spared even when eaten in small amounts, accumulating in the mid-long term. Another important dietary aspect is provided by its fatty acids composition that according to animal studies, seems to modulate fat oxidation. In addition to these, glycemic effects of CHO eaten in combination with the same meal can further potentiate fat storage. This proposal aims to test the dietary effects mentioned above by using indirect calorimetry in tandem with stable isotopes methodologies in a group of normal weight and obese women. (author)

  13. Thermography of volcanic areas on Piton de la Fournaise, Reunion Island : Mapping surface properties and possible detection of convective air flow within volcanic debris

    Science.gov (United States)

    Antoine, R.; Baratoux, D.; Rabinowicz, M.; Saracco, G.; Bachelery, P.; Staudacher, T.; Fontaine, F.

    2007-12-01

    We report on the detection of air convection in a couple of quasi circular cavities forming the 300 years old volcanically inactive cone of Formica Leo (Piton de la Fournaise, Reunion Island) [1]. Infrared thermal images of the cone have been acquired in 2006 from a hand held camera at regular time interval during a complete diurnal cycle. During night and dawn, the data display hot rims and cold centers. Both the conductivity contrasts of the highly porous soils filling the cavities and their 30° slopes are unable to explain the systematic rim to center temperature drop. Accordingly, this signal could be attributed to an air convection dipping inside the highly porous material at the center of each cavity, then flowing upslope along the base of the soil layer, before exiting it along the rims. Anemometrical and electrical data acquired in 2007 allow for the first time the direct detection of this air flow on the field: dipping gas velocities are measured at the center of the cone and self-potentials anomalies [2] generated by the humid air flow in the porous medium are detected. To quantify this process, we present 2D/3D numerical models of air convection in a sloped volcanic soil with a surface temperature evolving between day and night and taking into account electrical phenomena created by the air flow. At this present stage, this work constitutes a first step to investigate the deep structure of the active caldera of Bory-Dolomieu. The detection of the air flow at the surface could be of paramount importance for the understanding of volcanic hazards of the Reunion volcano. [1] Antoine et. al, submitted to G-Cubed [2] Darnet, PhD, Université Louis Pasteur (2003)

  14. Soil formation by termites, a study in the Kisii area, Kenya

    NARCIS (Netherlands)

    Wielemaker, W.G.

    1984-01-01

    Mineralogical and chemical characteristics of samples from a number of soils were used to demonstrate that soil materials from volcanic ash and local rock are thoroughly mixed.The mineralogy, micromorphology and grain-size distribution were studied to estimate the role of termites in mixing soil mat

  15. What are humic substances? : a molecular approach to the study of organic matter in acid soils

    NARCIS (Netherlands)

    Naafs, Derck Ferdinand Werner

    2004-01-01

    Molecular studies on the composition of organic matter in soils are scarce. In this thesis, a molecular approach to the study of organic matter in acid soils is presented, with a focus on andic, i.e. volcanic, soils. Analyses include both chemical extractions as well as pyrolysis-GC/MS and CPMAS 13C

  16. Geomagnetic imprint of the Persani volcanism

    Science.gov (United States)

    Besutiu, Lucian; Seghedi, Ioan; Zlagnean, Luminita; Atanasiu, Ligia; Popa, Razvan-Gabriel; Pomeran, Mihai; Visan, Madalina

    2016-04-01

    The Persani small volume volcanism is located in the SE corner of the Transylvanian Depression, at the north-western edge of the intra-mountainous Brasov basin. It represents the south-easternmost segment of the Neogene-Quaternary volcanic chain of the East Carpathians. The alkaline basalt monogenetic volcanic field is partly coeval with the high-K calc-alkaline magmatism south of Harghita Mountains (1-1.6 Ma). Its eruptions post-dated the calc-alkaline volcanism in the Harghita Mountains (5.3-1.6 Ma), but pre-dated the high-K calc-alkaline emissions of Ciomadul volcano (1.0-0.03 Ma). The major volcanic forms have been mapped in previous geological surveys. Still, due to the small size of the volcanoes and large extent of tephra deposits and recent sediments, the location of some vents or other volcanic structures has been incompletely revealed. To overcome this problem, the area was subject to several near-surface geophysical investigations, including paleomagnetic research. However, due to their large-scale features, the previous geophysical surveys proved to be an inappropriate approach to the volcanological issues. Therefore, during the summers of 2014 and 2015, based on the high magnetic contrast between the volcanic rocks and the hosting sedimentary formations, a detailed ground geomagnetic survey has been designed and conducted, within central Persani volcanism area, in order to outline the presence of volcanic structures hidden beneath the overlying deposits. Additionally, information on the rock magnetic properties was also targeted by sampling and analysing several outcrops in the area. Based on the acquired data, a detailed total intensity scalar geomagnetic anomaly map was constructed by using the recent IGRF12 model. The revealed pattern of the geomagnetic field proved to be fully consistent with the direction of magnetisation previously determined on rock samples. In order to enhance the signal/noise ratio, the results were further processed by

  17. Evidences for a volcanic province in the Central Indian Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Iyer, S.D.; Sudhakar, M.

    Based on various lines of evidence such as the widespread occurrence of basalts, pumice, volcanic glass shards and their transformational products (zeolites, palagonites, and smectite-rich sediments), we suggest the presence of a volcanic province...

  18. The influence of volcanic activity on suspended sediment yield of rivers (Kamchatka, Russia)

    Science.gov (United States)

    Kuksina, Ludmila

    2014-05-01

    period. Water turbidity reaches values of 1 - 6 kg/m3 for rivers with basin area of about 1000 km2 and 600 kg/m3 for rivers with basin area of about 100 km2. The maximum turbidity is observed in the eastern cost of Kamchatka, where the most active volcanoes are situated. Content of suspended particles decreases with the increase of distance from river basin to the active volcanoes. Zone of maximum turbidity in Kamchatka coincides with the Kliuchevskoy volcano group location, because there is no vegetation on active volcanoes, soils erodibility and rain-fall indexes are characterized by maximum values in this territory. Long-term regime of suspended sediment yield of rivers under influence of volcanism depends on volcanic eruptions. The maximum sediment yield in the Kamchatka River and in the Tolbachick River was formed after the most significant volcanic eruptions in 1956 (Bezymyanny volcano), 1964 (Shiveluch volcano) and 1975 - 1976 (Tolbachick volcano). On the basis of Wischmeier&Smith conception (Wischmeier, Smith, 1978) potential washout of suspended sediments and its transformation into suspended sediment yield were estimated for Kamchatka. The minimum transformation occurs in volcanic areas.

  19. Predicting Radiocaesium Sorption with Soil Chemical Properties in Japanese Soils

    International Nuclear Information System (INIS)

    The soil-to-plant transfer mechanism of radiocaesium (137Cs) in the Fukushima accident affected area is not fully understood. The sorption of 137Cs in soils holds a key to evaluating the variation of transfer of 137Cs to plant among different soil types. This study aims to investigate how differences in 137Cs adsorption in different soils can be explained by soil chemical and mineralogical properties. The Radiocaesium Interception Potential (RIP), a parameter for quantifying immediate 137Cs adsorption, and the soil texture were determined for 52 surface soils covering a wide range of texture classes collected from the area contaminated by the Fukushima accident. These soils include Andosols, Fluvisols, Gleysols, and Cambisols. In addition, we are currently performing analyses for other soil chemical properties (i.e. exchangeable cation, CEC, pH, organic matter content, etc) and for the properties affecting 137Cs sorption in soils (i.e. Frayed Edge Site capacity, K+ and NH4+ selectivity, effect of wet-dry cycles, etc). The average RIP varied from 80 to 4300 mmol kg-1 between soils. Contrary to what was found for temperate region soils by Absalom et al., the RIP (log(RIP)) and soil clay content were not significantly correlated (R2= 0.066). These initial results seem to indicate that the 137Cs sorption is affected by the clay mineralogy in soils. We postulate that by considering also the differences in clay K content, the relationship will improve since the frayed edges are formed at high K content in the clay. This knowledge could improve the prediction of RIP for different Japanese soil groups. Further analysis of the data will explore the relationship between RIP and other soil chemical properties. In our study, we will take specific note of Andosols (range of average RIP from 80 to 2400 mmol kg-1), typical soils in Japan originated from volcanic ash. It is expected that soil properties ruling the 137Cs sorption for Japanese Andosols will differ compared to other

  20. Predicting Radiocaesium Sorption with Soil Chemical Properties in Japanese Soils

    Energy Technology Data Exchange (ETDEWEB)

    Uematsu, Shinichiro [SCK.CEN, Belgian Nuclear Research Centre, Boeretang 200, B-2400 Mol (Belgium); Faculty of Bioscience Engineering, Katholieke Universiteit Leuven, Kasteelpark Arenberg 20, B-3001 Leuven (Belgium); Van Hees, May; Wannijn, Jean; Sweeck, Lieve; Vandenhove, Hildegarde [SCK.CEN, Belgian Nuclear Research Centre, Boeretang 200, B-2400 Mol (Belgium); Smolders, Erik [Faculty of Bioscience Engineering, Katholieke Universiteit Leuven, Kasteelpark Arenberg 20, B-3001 Leuven (Belgium)

    2014-07-01

    The soil-to-plant transfer mechanism of radiocaesium ({sup 137}Cs) in the Fukushima accident affected area is not fully understood. The sorption of {sup 137}Cs in soils holds a key to evaluating the variation of transfer of {sup 137}Cs to plant among different soil types. This study aims to investigate how differences in {sup 137}Cs adsorption in different soils can be explained by soil chemical and mineralogical properties. The Radiocaesium Interception Potential (RIP), a parameter for quantifying immediate {sup 137}Cs adsorption, and the soil texture were determined for 52 surface soils covering a wide range of texture classes collected from the area contaminated by the Fukushima accident. These soils include Andosols, Fluvisols, Gleysols, and Cambisols. In addition, we are currently performing analyses for other soil chemical properties (i.e. exchangeable cation, CEC, pH, organic matter content, etc) and for the properties affecting {sup 137}Cs sorption in soils (i.e. Frayed Edge Site capacity, K{sup +} and NH{sub 4}{sup +} selectivity, effect of wet-dry cycles, etc). The average RIP varied from 80 to 4300 mmol kg{sup -1} between soils. Contrary to what was found for temperate region soils by Absalom et al., the RIP (log(RIP)) and soil clay content were not significantly correlated (R2= 0.066). These initial results seem to indicate that the {sup 137}Cs sorption is affected by the clay mineralogy in soils. We postulate that by considering also the differences in clay K content, the relationship will improve since the frayed edges are formed at high K content in the clay. This knowledge could improve the prediction of RIP for different Japanese soil groups. Further analysis of the data will explore the relationship between RIP and other soil chemical properties. In our study, we will take specific note of Andosols (range of average RIP from 80 to 2400 mmol kg{sup -1}), typical soils in Japan originated from volcanic ash. It is expected that soil properties ruling

  1. Comparison of soil infiltration rates in burned and unburned mountainous watersheds

    Science.gov (United States)

    Martin, Deborah A.; Moody, John A.

    2001-10-01

    Steady-state infiltration measurements were made at mountainous sites in New Mexico and Colorado, USA, with volcanic and granitic soils after wildfires and at comparable unburned sites. We measured infiltration in the New Mexico volcanic soils under two vegetation types, ponderosa pine and mixed conifer, and in the Colorado granitic soils under ponderosa pine vegetation. These measurements were made within high-severity burn areas using a portable infiltrometer with a 0·017 m2 infiltration area and artificial rainfall rates ranging from 97 to 440 mm h-1. Steady-state infiltration rates were less at all burned sites relative to unburned sites. The volcanic soil with ponderosa pine vegetation showed the greatest difference in infiltration rates with a ratio of steady-state infiltration rate in burned sites to unburned soils equal to 0·15. Volcanic soils with mixed conifer vegetation had a ratio (burned to unburned soils) of at most 0·38, and granitic soils with ponderosa pine vegetation had a ratio of 0·38. Steady-state infiltration rates on unburned volcanic and granitic soils with ponderosa pine vegetation are not statistically different. We present data on the particle-size distribution at all the study sites and examples of wetting patterns produced during the infiltration experiments. Published in 2001 John Wiley & Sons, Ltd.

  2. Monitoring and forecasting Etna volcanic plumes

    Directory of Open Access Journals (Sweden)

    S. Scollo

    2009-09-01

    Full Text Available In this paper we describe the results of a project ongoing at the Istituto Nazionale di Geofisica e Vulcanologia (INGV. The objective is to develop and implement a system for monitoring and forecasting volcanic plumes of Etna. Monitoring is based at present by multispectral infrared measurements from the Spin Enhanced Visible and Infrared Imager on board the Meteosat Second Generation geosynchronous satellite, visual and thermal cameras, and three radar disdrometers able to detect ash dispersal and fallout. Forecasting is performed by using automatic procedures for: i downloading weather forecast data from meteorological mesoscale models; ii running models of tephra dispersal, iii plotting hazard maps of volcanic ash dispersal and deposition for certain scenarios and, iv publishing the results on a web-site dedicated to the Italian Civil Protection. Simulations are based on eruptive scenarios obtained by analysing field data collected after the end of recent Etna eruptions. Forecasting is, hence, supported by plume observations carried out by the monitoring system. The system was tested on some explosive events occurred during 2006 and 2007 successfully. The potentiality use of monitoring and forecasting Etna volcanic plumes, in a way to prevent threats to aviation from volcanic ash, is finally discussed.

  3. Monogenetic volcanism: personal views and discussion

    Science.gov (United States)

    Németh, K.; Kereszturi, G.

    2015-11-01

    Monogenetic volcanism produces small-volume volcanoes with a wide range of eruptive styles, lithological features and geomorphic architectures. They are classified as spatter cones, scoria (or cinder) cones, tuff rings, maars (maar-diatremes) and tuff cones based on the magma/water ratio, dominant eruption styles and their typical surface morphotypes. The common interplay between internal, such as the physical-chemical characteristics of magma, and external parameters, such as groundwater flow, substrate characteristics or topography, plays an important role in creating small-volume volcanoes with diverse architectures, which can give the impression of complexity and of similarities to large-volume polygenetic volcanoes. In spite of this volcanic facies complexity, we defend the term "monogenetic volcano" and highlight the term's value, especially to express volcano morphotypes. This study defines a monogenetic volcano, a volcanic edifice with a small cumulative volume (typically ≤1 km3) that has been built up by one continuous, or many discontinuous, small eruptions fed from one or multiple magma batches. This definition provides a reasonable explanation of the recently recognized chemical diversities of this type of volcanism.

  4. Monitoring and forecasting Etna volcanic plumes

    Science.gov (United States)

    Scollo, S.; Prestifilippo, M.; Spata, G.; D'Agostino, M.; Coltelli, M.

    2009-09-01

    In this paper we describe the results of a project ongoing at the Istituto Nazionale di Geofisica e Vulcanologia (INGV). The objective is to develop and implement a system for monitoring and forecasting volcanic plumes of Etna. Monitoring is based at present by multispectral infrared measurements from the Spin Enhanced Visible and Infrared Imager on board the Meteosat Second Generation geosynchronous satellite, visual and thermal cameras, and three radar disdrometers able to detect ash dispersal and fallout. Forecasting is performed by using automatic procedures for: i) downloading weather forecast data from meteorological mesoscale models; ii) running models of tephra dispersal, iii) plotting hazard maps of volcanic ash dispersal and deposition for certain scenarios and, iv) publishing the results on a web-site dedicated to the Italian Civil Protection. Simulations are based on eruptive scenarios obtained by analysing field data collected after the end of recent Etna eruptions. Forecasting is, hence, supported by plume observations carried out by the monitoring system. The system was tested on some explosive events occurred during 2006 and 2007 successfully. The potentiality use of monitoring and forecasting Etna volcanic plumes, in a way to prevent threats to aviation from volcanic ash, is finally discussed.

  5. Implications of volcanic erratics in Quaternary deposits of North Greenland

    DEFF Research Database (Denmark)

    Funder, Svend Visby; Larsen, Ole

    1982-01-01

    Erratic boulders, petrographically similar to the volcanics exposed around Kap Washington, are found on islands and along the coast much further to the east. Isotopic measurements on two such boulders show that these volcanic rocks are of the same age as the Kap Washington volcanics. The regional...

  6. Volcanic Ash Transport and Dispersion Forecasting

    Science.gov (United States)

    Servranckx, R.; Stunder, B.

    2006-12-01

    Volcanic ash transport and dispersion models (VATDM) have been used operationally since the mid 1990's by the International Civil Aviation Organization (ICAO) designated Volcanic Ash Advisory Centers (VAAC) to provide ash forecast guidance. Over the years, significant improvements in the detection and prediction of airborne volcanic ash have been realized thanks to improved models, increases in computing power, 24-hr real time monitoring by VAACs / Meteorological Watch Offices and close coordination with Volcano Observatories around the world. Yet, predicting accurately the spatial and temporal structures of airborne volcanic ash and the deposition at the earth's surface remains a difficult and challenging problem. The forecasting problem is influenced by 3 main components. The first one (ERUPTION SOURCE PARAMETERS) comprises all non-meteorological parameters that characterize a specific eruption or volcanic ash cloud. For example, the volume / mass of ash released in the atmosphere, the duration of the eruption, the altitude and distribution of the ash cloud, the particle size distribution, etc. The second component (METEOROLOGY) includes all meteorological parameters (wind, moisture, stability, etc.) that are calculated by Numerical Weather Prediction models and that serve as input to the VATDM. The third component (TRANSPORT AND DISPERSION) combines input from the other 2 components through the use of VATDM to transport and disperse airborne volcanic ash in the atmosphere as well as depositing it at the surface though various removal mechanisms. Any weakness in one of the components may adversely affect the accuracy of the forecast. In a real-time, operational response context such as exists at the VAACs, the rapid delivery of the modeling results puts some constraints on model resolution and computing time. Efforts are ongoing to evaluate the reliability of VATDM forecasts though the use of various methods, including ensemble techniques. Remote sensing data

  7. Contribution of allochthonous organic carbon across the Serrano River Basin and the adjacent fjord system in Southern Chilean Patagonia: Insights from the combined use of stable isotope and fatty acid biomarkers

    Science.gov (United States)

    Lafon, Alejandra; Silva, Nelson; Vargas, Cristian A.

    2014-12-01

    Chilean Patagonia is characterized by an irregular geography involving many islands, peninsulas, channels, sounds and fjords, that prevent direct interaction between oceanic water masses and freshwater river discharges at the head of the continental fjords. In this paper, we evaluate the potential sources and composition of organic matter along the Serrano River basin and the adjacent channels and fjords in Southern Chilean Patagonia (51-52°S), as well as their importance for marine planktonic organisms. In spring of 2009, evidence of C:N ratio, δ13C, δ15N and fatty acids composition in particulate organic carbon (POC), surface sediment, soil, plankton, and vegetal tissue, as well some physical and chemical characteristics (i.e. salinity, dissolved oxygen, NO3-, NH4+, PO4-3, Si(OH)4), were measured in samples collected during the CIMAR 14 Fiordos oceanographic cruise. Significant differences in δ13C-POC were found between the terrestrial and marine environments but not within fjord stations. Along the fjord region, the high C:N ratio and depleted δ13C values in POC samples suggest that particulate organic matter (POM) in the upper level of the water column (0-10 m depth) is supported by different sources. Terrestrial organic carbon exported by rivers may constitute a significant subsidy, up to 70% based on two end-member mixing model, to the fjord ecosystem. Furthermore, terrestrial carbon might account for a significant percentage of the zooplankton body carbon, estimated both by using isotopic (∼24-61%) and fatty acid analysis (∼14-61%). Isotopic analyses in marine sediment samples suggest that POC seems to be decoupled from terrestrial-influenced surface sources at the fjord stations, and the contribution of surrounding vegetation seemingly unimportant for carbon export to the benthos. Local hydrographic and geomorphological characteristics might determine the presence of oceanographic frontal zones, which in turn might explain differences in carbon

  8. Volcanic Plume Chemistry: Models, Observations and Impacts

    Science.gov (United States)

    Roberts, Tjarda; Martin, Robert; Oppenheimer, Clive; Griffiths, Paul; Braban, Christine; Cox, Tony; Jones, Rod; Durant, Adam; Kelly, Peter

    2010-05-01

    Volcanic plumes are highly chemically reactive; both in the hot, near-vent plume, and also at ambient temperatures in the downwind plume, as the volcanic gases and aerosol disperse into the background atmosphere. In particular, DOAS (Differential Optical Absortpion Spectroscopy) observations have identified BrO (Bromine Monoxide) in several volcanic plumes degassing into the troposphere. These observations are explained by rapid in-plume autocatalytic BrO-chemistry that occurs whilst the plume disperses, enabling oxidants such as ozone from background air to mix with the acid gases and aerosol. Computer modelling tools have recently been developed to interpret the observed BrO and predict that substantial ozone depletion occurs downwind. Alongside these modelling developments, advances in in-situ and remote sensing techniques have also improved our observational understanding of volcanic plumes. We present simulations using the model, PlumeChem, that predict the spatial distribution of gases in volcanic plumes, including formation of reactive halogens BrO, ClO and OClO that are enhanced nearer the plume edges, and depletion of ozone within the plume core. The simulations also show that in-plume chemistry rapidly converts NOx into nitric acid, providing a mechanism to explain observed elevated in-plume HNO3. This highlights the importance of coupled BrO-NOx chemistry, both for BrO-formation and as a production mechanism for HNO3 in BrO-influenced regions of the atmosphere. Studies of coupled halogen-H2S-chemistry are consistent with in-situ Alphasense electrochemical sensor observations of H2S at a range of volcanoes, and only predict H2S-depletion if Cl is additionally elevated. Initial studies regarding the transformations of mercury within volcanic plumes suggest that significant in-plume conversion of Hg0 to Hg2+ can occur in the downwind plume. Such Hg2+ may impact downwind ecology through enhanced Hg-deposition, and causing enhanced biological uptake of

  9. Holocene explosive volcanism of the Jan Mayen (island) volcanic province, North-Atlantic

    Science.gov (United States)

    Gjerløw, Eirik; Haflidason, H.; Pedersen, R. B.

    2016-07-01

    The volcanic island Jan Mayen, located in the Norwegian-Greenland Sea, hosts the active stratovolcano of Beerenberg, the northernmost active subaerial volcano in the world. At least five eruptions are known from the island following its discovery in the 17th century, but its eruptive history prior to this is basically unknown. In this paper two sediment cores retrieved close to Jan Mayen have been studied in detail to shed light on the Holocene history of explosive volcanism from the Jan Mayen volcanic province. Horizons with elevated tephra concentrations were identified and tephra from these was analysed to determine major element chemistry of the tephra. The tephra chemistry was used to provide a link between the two cores and the land based tephra records from Jan Mayen Island. We managed to link two well-developed tephra peaks in the cores by their geochemical composition and age to Jan Mayen. One of these peaks represents the 1732 AD eruption of Eggøya while the other peak represents a previously undescribed eruption dated to around 10.3 ka BP. Two less prominent tephra peaks, one in each core, dated to approximately 2.3 and 3.0 ka BP, also have a distinct geochemical character linking them to Jan Mayen volcanism. However, the most prominent tephra layer in the cores located close to Jan Mayen and numerous other cores along the Jan Mayen ridge is the 12.1 ka BP Vedde Ash originating from the Iceland volcanic province. We find that the Holocene volcanism on Jan Mayen is much less explosive than volcanism in Iceland, and propose that either low amounts of explosive volcanic activity from the summit region of Beerenberg or small to absent glacier cover on Beerenberg is responsible for this.

  10. International Database of Volcanic Ash Impacts

    Science.gov (United States)

    Wallace, K.; Cameron, C.; Wilson, T. M.; Jenkins, S.; Brown, S.; Leonard, G.; Deligne, N.; Stewart, C.

    2015-12-01

    Volcanic ash creates extensive impacts to people and property, yet we lack a global ash impacts catalog to organize, distribute, and archive this important information. Critical impact information is often stored in ephemeral news articles or other isolated resources, which cannot be queried or located easily. A global ash impacts database would improve 1) warning messages, 2) public and lifeline emergency preparation, and 3) eruption response and recovery. Ashfall can have varying consequences, such as disabling critical lifeline infrastructure (e.g. electrical generation and transmission, water supplies, telecommunications, aircraft and airports) or merely creating limited and expensive inconvenience to local communities. Impacts to the aviation sector can be a far-reaching global issue. The international volcanic ash impacts community formed a committee to develop a database to catalog the impacts of volcanic ash. We identify three user populations for this database: 1) research teams, who would use the database to assist in systematic collection, recording, and storage of ash impact data, and to prioritize impact assessment trips and lab experiments 2) volcanic risk assessment scientists who rely on impact data for assessments (especially vulnerability/fragility assessments); a complete dataset would have utility for global, regional, national and local scale risk assessments, and 3) citizen science volcanic hazard reporting. Publication of an international ash impacts database will encourage standardization and development of best practices for collecting and reporting impact information. Data entered will be highly categorized, searchable, and open source. Systematic cataloging of impact data will allow users to query the data and extract valuable information to aid in the development of improved emergency preparedness, response and recovery measures.

  11. Geohazards (floods and landslides in the Ndop plain, Cameroon volcanic line

    Directory of Open Access Journals (Sweden)

    Wotchoko Pierre

    2016-07-01

    Full Text Available The Ndop Plain, located along the Cameroon Volcanic Line (CVL, is a volcano-tectonic plain, formed by a series of tectonic movements, volcanic eruptions and sedimentation phases. Floods (annually and landslides (occasionally occur with devastating environmental effects. However, this plain attracts a lot of inhabitants owing to its fertile alluvial soils. With demographic explosion in the plain, the inhabitants (143,000 people tend to farm and inhabit new zones which are prone to these geohazards. In this paper, we use field observations, laboratory analyses, satellite imagery and complementary methods using appropriate software to establish hazard (flood and landslide maps of the Ndop Plain. Natural factors as well as anthropogenic factors are considered.

  12. Magneto-chemical properties of mollic andosols from the Rungwe volcanic province (Tanzania): climate and landuse implications

    Science.gov (United States)

    Williamson, D.; Mathé, P.-E.; Majule, A.; Vadeboin, F.

    2003-04-01

    To investigate the sensitivity of tropical volcanic soils to climate and landuse, discrete rock magnetic analysis coupled with major and rare-earth element analysis (ICP-AES) were performed on mollic andosols developped on a regional Early Holocene pumice horizon, in the Rungwe volcanic province (southwestern Tanzania). A reference profile (MP1, 130 cm) was first established at the top of the Masoko crater (700m altitude) and subsequently compared with soils located along a contrasted climate/landuse gradient, between 700 and 2700 m altitude. Ti and Nb concentrations were used as normalization parameters to estimate the pedogenic enhancement (ETi and ENb) relatively to the parent volcanic pumice (C horizon). Ti-normalized magnetic concentration proxies show a characteristic enhancement in the Bt horizon (80 to 350%), especially near the Ah/Bt and Bt/C horizons. Maximum ETi values are observed for saturation magnetization J_s and frequency-dependent susceptibility χ (FD) (>300%), indicating a significant enhancement in (ultra)fine SP iron oxides. Comparison with ENb values suggest that the Bt/C magnetic enhancement likely originates from the dissolution of volcanic glass, while the upper Ah/Bt enhancement may result from authigenesis processes. Most regional, non-disturbed Miombo or afromontane soils present similar properties. In contrast, dramatic changes in Ah/Bt enhancement and soil thickness are observed in sites where traditional soil regeneration practices (fallows) were replaced by intensive cultivation practices during the colonial period (ca. 1887-1915). Contribution of the CLEHA/ECLIPSE and RESOLVE projects.

  13. A geologic and anthropogenic journey from the Precambrian to the new energy economy through the San Juan volcanic field

    Science.gov (United States)

    Yager, Douglas B.; Burchell,; Johnson, Raymond H.

    2010-01-01

    The San Juan volcanic field comprises 25,000 km2 of intermediate composition mid-Tertiary volcanic rocks and dacitic to rhyolitic calderas including the San Juan–Uncompahgre and La Garita caldera-forming super-volcanoes. The region is famous for the geological, ecological, hydrological, archeological, and climatological diversity. These characteristics supported ancestral Puebloan populations. The area is also important for its mineral wealth that once fueled local economic vitality. Today, mitigating and/or investigating the impacts of mining and establishing the region as a climate base station are the focuses of ongoing research. Studies include advanced water treatment, the acid neutralizing capacity (ANC) of propylitic bedrock for use in mine-lands cleanup, and the use of soil amendments including biochar from beetle-kill pines. Biochar aids soil productivity and revegetation by incorporation into soils to improve moisture retention, reduce erosion, and support the natural terrestrial carbon sequestration (NTS) potential of volcanic soils to help offset atmospheric CO2 emissions. This field trip will examine the volcano-tectonic and cultural history of the San Juan volcanic field as well as its geologic structures, economic mineral deposits and impacts, recent mitigation measures, and associated climate research. Field trip stops will include a visit to (1) the Summitville Superfund site to explore quartz alunite-Au mineralization, and associated alteration and new water-quality mitigation strategies; (2) the historic Creede epithermal-polymetallic–vein district with remarkably preserved resurgent calderas, keystone-graben, and moat sediments; (3) the historic mining town of Silverton located in the nested San Juan–Silverton caldera complex that exhibits base-metal Au-Ag mineralization; and (4) the site of ANC and NTS studies. En route back to Denver, we will traverse Grand Mesa, a high NTS area with Neogene basalt-derived soils and will enjoy a soak

  14. Co-evolution of volcanic catchments in Japan

    Directory of Open Access Journals (Sweden)

    T. Yoshida

    2015-09-01

    Full Text Available Present day landscapes have evolved over time through interactions between the prevailing climates and geological settings. Understanding the linkage between spatial patterns of landforms, soils, and vegetation in landscapes and their hydrological response is critical to make quantitative predictions in ungaged basins. Catchment co-evolution is a theoretical framework that seeks to formulate hypotheses about the mechanisms and conditions that determine the historical development of catchments and how such evolution affects their hydrological response. In this study, we selected 14 volcanic catchments of different ages (from 0.225 to 82.2 Ma in Japan. We derived indices of landscape properties (drainage density as well as hydrological response (annual water balance, baseflow index, and flow duration curves and examined their relation with catchment age and climate (through the aridity index. We found significant correlation between drainage density and baseflow index with age, but not with climate. The age of the catchments was also significantly related to intra-annual flow variability. Younger catchments tend to have lower peak flows and higher low flows, while older catchments exhibit more flashy runoff. The decrease of baseflow with catchment age confirms previous studies that hypothesized that in volcanic landscapes the major flow pathways have changed over time, from deep groundwater flow to shallow subsurface flow. The drainage density of our catchments decreased with age, contrary to previous findings in similar volcanic catchments but of significant younger age than the ones explored here. In these younger catchments, an increase in drainage density with age was observed, and it was hypothesized that this was because of more landscape incision due to increasing near-surface lateral flow paths in more mature catchments. Our results suggests two hypotheses on the evolution of drainage density in matured catchments. One is that as

  15. Relationship of Adiposity and Insulin Resistance Mediated by Inflammation in a Group of Overweight and Obese Chilean Adolescents

    OpenAIRE

    Leiva Laura; Blanco Estela; Díaz Erik; Gahagan Sheila; Reyes Marcela; Lera Lydia; Burrows Raquel

    2011-01-01

    Abstract The mild chronic inflammatory state associated with obesity may be an important link between adiposity and insulin resistance (IR). In a sample of 137 overweight and obese Chilean adolescents, we assessed associations between high-sensitivity C-reactive protein (hs-CRP), IR and adiposity; explored sex differences; and evaluated whether hs-CRP mediated the relationship between adiposity and IR. Positive relationships between hs-CRP, IR and 2 measures of adiposity were found. Hs-CRP wa...

  16. Small Scale Indigenous Molybdenum-99 Production Using LEU Fission at Chilean Nuclear Energy Commission [Country report: Chile

    International Nuclear Information System (INIS)

    This report contains the results of the activities carried out in the Chilean Nuclear Energy Commission (CCHEN) under CRP Nº 13358 “Small Scale Indigenous Molybdenum-99 Production Using LEU Fission” started in October 2005 to November 2011. The object of the project was to develop the basic infrastructure and to establish the conditions to obtain fission molybdenum-99 (99Mo) by neutron irradiation of uranium-235 (235U) targets in RECH-1 reactor located in Santiago, Chile

  17. Cadmium bioaccumulation and retention kinetics in the Chilean blue mussel Mytilus chilensis: Seawater and food exposure pathways

    Energy Technology Data Exchange (ETDEWEB)

    Herve-Fernandez, Pedro [Instituto de Geociencias, Universidad Austral de Chile, Castilla 567, Valdivia (Chile); Houlbreque, Fanny, E-mail: F.Houlbreque@iaea.org [International Atomic Energy Agency - Marine Environment Laboratories, 4 Quai Antoine 1er, 98000 Monaco (Monaco); Boisson, Florence [International Atomic Energy Agency - Marine Environment Laboratories, 4 Quai Antoine 1er, 98000 Monaco (Monaco); Mulsow, Sandor [Instituto de Geociencias, Universidad Austral de Chile, Castilla 567, Valdivia (Chile); Teyssie, Jean-Louis; Oberhaensli, Francois; Azemard, Sabine; Jeffree, Ross [International Atomic Energy Agency - Marine Environment Laboratories, 4 Quai Antoine 1er, 98000 Monaco (Monaco)

    2010-09-15

    The Chilean blue mussel (Mytilus chilensis, Hupe 1854) represents the most important bivalve exploited along the Chilean coast and is a major food source for the Chilean population. Unfortunately, local fish and shellfish farming face severe problems as a result of bioaccumulation of toxic trace metals into shellfishes. Blue mussels collected along the Chilean coasts contain levels of Cd above the regulatory limits for human consumption. In this study, we examined the bioaccumulation, depuration and organ distribution of Cd in the M. chilensis, from {sup 109}Cd-labelled bulk seawater and from feeding with {sup 109}Cd-labelled algae. The uptake of {sup 109}Cd via seawater displayed a simple exponential kinetic model suggesting that cadmium activity tends to reach an equilibrium value of 1.838 {+-} 0.175 ng g{sup -1} (mean {+-} asymptotic standard error, p < 0.001) after 78 {+-} 9 days. The depuration rate for {sup 109}Cd accumulated via seawater was slow, with only 21% of the total {sup 109}Cd accumulated in the whole mussel being eliminated after 52 days. Total elimination of Cd in mussels was adequately described by a double component kinetic model, in which the biological half-life for the long-lived component represents more than 6 months. In contrast, depuration after radiolabelled food uptake was fast, reaching only 20% of retention in 10 days. This knowledge of the long half-life of cadmium accumulated via seawater as well as the non-negligible level of cadmium accumulated into the shells is relevant to the management of Cd levels in this species and the refinement of detoxification processes in order to comply with authorized Cd levels.

  18. Policy learning and policy change in a context of industry crisis: the case of Chilean salmon farming industry

    OpenAIRE

    Roa Petrasic, Veronica Alejandra

    2015-01-01

    This research investigates the policy response to the 2007-2010 sanitary crisis in the Chilean salmon industry, the second largest producer and exporter of salmon in the world. This industry is an emblematic case of the possible consequences of employing an intensive natural resource model for development. The research draws upon the two literatures on policy learning and policy change, and crisis and disaster management, and upon the system failure to explain the causes and consequences ...

  19. [Rotavirus Vaccine. Statement of the Consultive Committee of Immunizations on behalf of The Chilean Infectious Diseases Society. March 2006].

    Science.gov (United States)

    Muñoz M, Alma; Abarca V, Katia; Luchsinger F, Vivian; Valenzuela B, M Teresa; Jiménez de la J, Jorge

    2006-06-01

    The article briefly reviews the epidemiology of rotavirus infection and the scientific information of the rotavirus vaccines: Rotashield, withdrawn from the market due to its association with intussusception, Rotateq currently in an advanced phase of development, and Rotarix, recently licensed in Chile. Considering the available information, the Consultive Committee of Immunizations of the Chilean Society of Infectious Diseases, summarizes its conclusions and makes recommendations for infants vaccination against rotavirus in our country.

  20. Values, animal symbolism, and human-animal relationships associated to two threatened felids in Mapuche and Chilean local narratives

    OpenAIRE

    Herrmann, Thora M; Schüttler, Elke; Benavides, Pelayo; Gálvez, Nicolas; Söhn, Lisa; Palomo, Nadja

    2013-01-01

    Background The Chilean temperate rainforest has been subjected to dramatic fragmentation for agriculture and forestry exploitation. Carnivore species are particularly affected by fragmentation and the resulting resource use conflicts with humans. This study aimed at understanding values and human-animal relationships with negatively perceived threatened carnivores through the disclosure of local stories and Mapuche traditional folktales. Methods Our mixed approach comprised the qualitative an...

  1. Chemical and botanical characterization of Chilean propolis and biological activity on cariogenic bacteria Streptococcus mutans and Streptococcus sobrinus

    OpenAIRE

    Leticia Barrientos; Herrera, Christian L.; Gloria Montenegro; Ximena Ortega; Jorge Veloz; Marysol Alvear; Alejandro Cuevas; Nicolás Saavedra; Salazar, Luis A.

    2013-01-01

    Propolis is a non-toxic natural substance with multiple pharmacological properties including anti-cancer, antioxidant, fungicidal, antibacterial, antiviral, and anti-inflammatory among others. The aim of this study was to determine the chemical and botanical characterization of Chilean propolis samples and to evaluate their biological activity against the cariogenic bacteria Streptococcus mutans and Streptococcus sobrinus. Twenty propolis samples were obtained from beekeeping producers from t...

  2. Cadmium bioaccumulation and retention kinetics in the Chilean blue mussel Mytilus chilensis: Seawater and food exposure pathways

    International Nuclear Information System (INIS)

    The Chilean blue mussel (Mytilus chilensis, Hupe 1854) represents the most important bivalve exploited along the Chilean coast and is a major food source for the Chilean population. Unfortunately, local fish and shellfish farming face severe problems as a result of bioaccumulation of toxic trace metals into shellfishes. Blue mussels collected along the Chilean coasts contain levels of Cd above the regulatory limits for human consumption. In this study, we examined the bioaccumulation, depuration and organ distribution of Cd in the M. chilensis, from 109Cd-labelled bulk seawater and from feeding with 109Cd-labelled algae. The uptake of 109Cd via seawater displayed a simple exponential kinetic model suggesting that cadmium activity tends to reach an equilibrium value of 1.838 ± 0.175 ng g-1 (mean ± asymptotic standard error, p 109Cd accumulated via seawater was slow, with only 21% of the total 109Cd accumulated in the whole mussel being eliminated after 52 days. Total elimination of Cd in mussels was adequately described by a double component kinetic model, in which the biological half-life for the long-lived component represents more than 6 months. In contrast, depuration after radiolabelled food uptake was fast, reaching only 20% of retention in 10 days. This knowledge of the long half-life of cadmium accumulated via seawater as well as the non-negligible level of cadmium accumulated into the shells is relevant to the management of Cd levels in this species and the refinement of detoxification processes in order to comply with authorized Cd levels.

  3. [To kill, let die and euthanasia in the bill of rights of patients and in the Chilean doctrine].

    Science.gov (United States)

    Figueroa G, Rodolfo

    2011-05-01

    The Bill of Rights for Patients provides the patient with autonomy for disposing of his life, enabling him to reject those treatments that unnecessarily prolong his life. However, the bill does not allow an artificial acceleration of death. Therefore, the bill does not permit euthanasia (at least, certain form of it) nor assisted-suicide. However, according to the practice of medicine and also Chilean doctrine, it is permitted to inject morphine to a patient to relieve his pain, even though that could hasten his death. In consequence, it is allowed for the patient to dispose of his life and also to inject in him morphine for pain relief, endangering his life, but neither euthanasia nor assisted-suicide is allowed. Is this coherent? According to Chilean doctrine, it could be coherent under the condition of accepting the distinction between killing and letting die and also the double effect doctrine. The problem is that there is abundant English literature in the realm of moral philosophy to disregard both conditions. Therefore, it is possible to claim that the Bill is not coherent and that the Chilean doctrine is based upon a distinction and a doctrine that are not acceptable. PMID:22051718

  4. Impact of Mano a Mano-Mujer, an HIV prevention intervention, on depressive symptoms among Chilean women.

    Science.gov (United States)

    Cianelli, R; Lara, L; Villegas, N; Bernales, M; Ferrer, L; Kaelber, L; Peragallo, N

    2013-04-01

    Worldwide, and in Chile, the number of women living with HIV is increasing. Depression is considered a factor that interferes with HIV prevention. Depression may reach 41% among low-income Chilean women. Depressed people are less willing to participate in behaviours that protect them against HIV. The aim of this study is to analyze the impact of Mano a Mano-Mujer (MM-M), and HIV prevention intervention, on depressive symptoms among Chilean women. A quasi-experimental design was used for this study. The research was conducted in Santiago, Chile; a total of 400 women participated in the study (intervention group, n=182; control group, n=218). The intervention was guided by the social-cognitive model and the primary health care model. The intervention consists of six 2-h sessions delivered in small groups. Sessions covered: HIV prevention, depression, partner's communication, and substance abuse. Face-to-face interviews were conducted at baseline and at 3-month follow-up. Chilean women who participated in MM-M significantly decreased, at 3 months follow up, their reported depressive symptoms. MM-M provided significant benefits for women's depression symptoms. In this study nurses participated as leaders for the screening of depressive symptoms and as facilitators of community interventions.

  5. 2 × 2 achievement goals profilEs in chilean CompetiTIve and recreational athletes: a first look

    Directory of Open Access Journals (Sweden)

    Lochbaum Marc R.

    2016-01-01

    Full Text Available Purpose: was to examine the 2 × 2 achievement goal profiles of Chilean young adults regularly participating in competitive and recreational sport. Materials: participants were 108 female and 132 males who were recruited from the Valparaiso and Viña del Mar areas of Chile. Participants completed a valid and reliable measure of the 2 × 2 achievement goals referenced to sport participation. Results: indicated that the entire sample significantly ( p < .05 and very meaningfully (Hedges’ g range 1.13 - 2.91 endorsed the mastery-approach goal more so than the other three achievement goals. Male participants significantly ( p < .05 endorsed both approach goals and the mastery goal contrast more so than the female participants. These differences approached medium in meaningfulness (Hedges’ g range .40 - .46. Significant differences did not exist between competitive and recreational athletes on any of the achievement goals or goal contrasts. Confirming the lack of significant differences were the computed small to negligible in magnitude effect sizes. Conclusions: the present data were a first look into profiling sport participants on the 2 × 2 achievement goals in Chile. Given this sample of Chilean participants endorsed the performance goals far less than found in the sport psychology 2 × 2 achievement goal literature, more research is needed before these results are generalized to Chilean sport participants. Future research must also examine the relationships of antecedents and consequences to the 2 × 2 achievement goals to advance sport psychology in Chile.

  6. Rates of soil development from four soil chronosequences in the southern Great Basin

    Science.gov (United States)

    Harden, J.W.; Taylor, E.M.; Hill, C.; Mark, R.K.; McFadden, L.D.; Reheis, M.C.; Sowers, J.M.; Wells, S.G.

    1991-01-01

    Four soil chronosequences in the southern Great Basin were examined in order to study and quantify soil development during the Quaternary. Soils of all four areas are developed in gravelly alluvial fans in semiarid climates with 8 to 40 cm mean annual precipitation. Lithologies of alluvium are granite-gneiss at Silver Lake, granite and basalt at Cima Volcanic Field, limestone at Kyle Canyon, and siliceous volcanic rocks at Fortymile Wash. Ages of the soils are approximated from several radiometric and experimental techniques, and rates are assessed using a conservative mathematical approach. Average rates for Holocene soils at Silver Lake are about 10 times higher than for Pleistocene soils at Kyle Canyon and Fortymile Wash, based on limited age control. Holocene soils in all four areas appear to develop at similar rates, and Pleistocene soils at Kyle Canyon and Fortymile Wash may differ by only a factor of 2 to 4. Over time spans of several millennia, a preferred model for the age curves is not linear but may be exponential or parabolic, in which rates decrease with increasing age. These preliminary results imply that the geographical variation in rates within the southern Great Basin-Mojave region may be much less significant than temporal variation in rates of soil development. The reasons for temporal variation in rates and processes of soil development are complexly linked to climatic change and related changes in water and dust, erosional history, and internally driven chemical and physical processes. ?? 1991.

  7. Using Spatial Density to Characterize Volcanic Fields on Mars

    Science.gov (United States)

    Richardson, J. A.; Bleacher, J. E.; Connor, C. B.; Connor, L. J.

    2012-01-01

    We introduce a new tool to planetary geology for quantifying the spatial arrangement of vent fields and volcanic provinces using non parametric kernel density estimation. Unlike parametricmethods where spatial density, and thus the spatial arrangement of volcanic vents, is simplified to fit a standard statistical distribution, non parametric methods offer more objective and data driven techniques to characterize volcanic vent fields. This method is applied to Syria Planum volcanic vent catalog data as well as catalog data for a vent field south of Pavonis Mons. The spatial densities are compared to terrestrial volcanic fields.

  8. Diffuse CO2 emission from the NE volcanic rift-zone of Tenerife (Canary Islands, Spain): a 15 years geochemical monitoring

    Science.gov (United States)

    Padilla, Germán; Alonso, Mar; Shoemaker, Trevor; Loisel, Ariane; Padrón, Eleazar; Hernández, Pedro A.; Pérez, Nemesio M.

    2016-04-01

    The North East Rift (NER) volcanic zone of Tenerife Island is one of the three volcanic rift-zones of the island (210 km2). The most recent eruptive activity along the NER volcanic zone took place in the 1704-1705 period with the volcanic eruptions of Siete Fuentes, Fasnia and Arafo volcanoes. The aim of this study was to report the results of a soil CO2 efflux survey undertaken in June 2015, with approximately 580 measuring sites. In-situ measurements of CO2 efflux from the surface environment of NER volcanic zone were performed by means of a portable non-dispersive infrared spectrophotometer (NDIR) model LICOR Li800 following the accumulation chamber method. To quantify the total CO2 emission from NER volcanic zone, soil CO2 efflux contour maps were constructed using sequential Gaussian simulation (sGs) as interpolation method. The total diffuse CO2 emission rate was estimated in 1209 t d-1, with CO2 efflux values ranging from non-detectable (˜0.5 g m-2 d-1) up to 123 g m-2 d-1, with an average value of 5.9 g m-2 d-1. If we compare these results with those obtained in previous surveys developed in a yearly basis, they reveal slightly variations from 2006 to 2015, with to pulses in the CO2 emission observed in 2007 and 2014. The main temporal variation in the total CO2 output does not seem to be masked by external variations. First peak precedes the anomalous seismicity registered in and around Tenerife Island between 2009 and 2011, suggesting stress-strain changes at depth as a possible cause for the observed changes in the total output of diffuse CO2 emission. Second peak could be related with futures changes in the seismicity. This study demonstrates the importance of performing soil CO2 efflux surveys as an effective surveillance volcanic tool.

  9. Functional comparisons between unimodal and bimodal analytical relationships in terms of water balance predictions for the case study of the Vesuvius volcanic area (Naples, Southern Italy).

    Science.gov (United States)

    Romano, Nunzio; Nasta, Paolo

    2015-04-01

    Optimal performance of large-scale numerical modeling of the soil-vegetation-atmosphere (SVA) system mandates accurate assessment and description of the soil hydraulic properties, namely the water retention (WRF) and hydraulic conductivity (HCF) functions. These functions are commonly described by simple unimodal analytical relations that guarantee mathematical flexibility with few parameters in the majority of soil types. However, other soils, like volcanic soils, are characterized by a complex structure yielding a bimodal or even a multimodal distribution of pore sizes. In these cases, reliable hydrologic predictions can be obtained resorting to more complex hydraulic functions, yet more accurate and robust ones. To overcome some drawbacks of the classic unimodal hydraulic relationships, Romano et al. (2011) have developed closed-form bimodal lognormal relations for improving the description of both WRF and HCF. However, the reliability of this description of the soil hydraulic behavior is often tested at the curve fitting level only. Comparisons between unimodal and bimodal soil hydraulic relationships are more effective and informative when performed in functional terms. Therefore, as the primary objective of this study, we used a hydrological balance model to quantify and compare soil moisture flow and storage regimes for 14 years (1999-2012), when characterized by unimodal or bimodal approximations of 39 measured soil water retention and hydraulic conductivity characteristics collected in volcanic Vesuvian soil located in the Campania Region Plain (Naples, Southern Italy).

  10. Electrical charging of ash in Icelandic volcanic plumes

    CERN Document Server

    Aplin, Karen L; Nicoll, Keri A

    2014-01-01

    The existence of volcanic lightning and alteration of the atmospheric potential gradient in the vicinity of near-vent volcanic plumes provides strong evidence for the charging of volcanic ash. More subtle electrical effects are also visible in balloon soundings of distal volcanic plumes. Near the vent, some proposed charging mechanisms are fractoemission, triboelectrification, and the so-called "dirty thunderstorm" mechanism, which is where ash and convective clouds interact electrically to enhance charging. Distant from the vent, a self-charging mechanism, probably triboelectrification, has been suggested to explain the sustained low levels of charge observed on a distal plume. Recent research by Houghton et al. (2013) linked the self-charging of volcanic ash to the properties of the particle size distribution, observing that a highly polydisperse ash distribution would charge more effectively than a monodisperse one. Natural radioactivity in some volcanic ash could also contribute to self-charging of volcan...

  11. A permanent record of subduction zone earthquake cycle deformation in the northern Chilean forearc

    Science.gov (United States)

    Loveless, J. P.; Allmendinger, R. W.; Pritchard, M. E.; González, G.

    2006-12-01

    Patterns of faulting in the northern Chilean forearc are consistent with modeled stress fields resulting from the subduction zone earthquake cycle. We define positive Coulomb stress change as encouraging normal faulting motion on steeply-dipping planes striking approximately parallel to the plate boundary, as shown by fault kinematic data collected in the field. Simulations show that coastal regions experience positive Coulomb stress changes due to interseismic strain accumulation on the subduction interface. This is compatible with the structural character of the forearc, typified by 100 m-scale scarps constructed by normal faulting. Conversely, the best-constrained models of interplate slip associated with the 1995 Mw 8.0 Antofagasta earthquake indicate that near-surface coastal areas experienced either zero or negative coseismic stress change, implying that subduction zone earthquakes may be capable of driving reverse motion on these structures if the absolute stress level is sufficiently low. Field exposures show minor amounts of reverse reactivation of some normal faults, expressed both through bedrock exposure and scarp morphology. The consistency between deformation fields related to the seismic cycle and permanent strain demonstrated by observable structures argues for the long-term influence of the earthquake cycle on the structural evolution of the forearc. The distribution of normal and reverse faulting as well as open cracks can thus be used to gain insight into the plate boundary processes that drive the evolution of structures. The change in strike and eastward step of the Atacama Fault System around the latitude of the Mejillones Peninsula (23°S) coincides with a change in subduction zone locking depth from ~35 km south of the peninsula to ~50 km to the north as determined through analyses of teleseismic, local seismic, and GPS data. Dense arrays of open cracks in several forearc localities show mean strikes consistent with static extension axes

  12. High genetic diversity in a small population: the case of Chilean blue whales.

    Science.gov (United States)

    Torres-Florez, Juan P; Hucke-Gaete, Rodrigo; Rosenbaum, Howard; Figueroa, Christian C

    2014-04-01

    It is generally assumed that species with low population sizes have lower genetic diversities than larger populations and vice versa. However, this would not be the case for long-lived species with long generation times, and which populations have declined due to anthropogenic effects, such as the blue whale (Balaenoptera musculus). This species was intensively decimated globally to near extinction during the 20th century. Along the Chilean coast, it is estimated that at least 4288 blue whales were hunted from an apparently pre-exploitation population size (k) of a maximum of 6200 individuals (Southeastern Pacific). Thus, here, we describe the mtDNA (control region) and nDNA (microsatellites) diversities of the Chilean blue whale aggregation site in order to verify the expectation of low genetic diversity in small populations. We then compare our findings with other blue whale aggregations in the Southern Hemisphere. Interestingly, although the estimated population size is small compared with the pre-whaling era, there is still considerable genetic diversity, even after the population crash, both in mitochondrial (N = 46) and nuclear (N = 52) markers (Hd = 0.890 and Ho = 0.692, respectively). Our results suggest that this diversity could be a consequence of the long generation times and the relatively short period of time elapsed since the end of whaling, which has been observed in other heavily-exploited whale populations. The genetic variability of blue whales on their southern Chile feeding grounds was similar to that found in other Southern Hemisphere blue whale feeding grounds. Our phylogenetic analysis of mtDNA haplotypes does not show extensive differentiation of populations among Southern Hemisphere blue whale feeding grounds. The present study suggests that although levels of genetic diversity are frequently used as estimators of population health, these parameters depend on the biology of the species and should be taken into account in a

  13. Adaptation of the spiders to the environment: the case of some Chilean species

    Science.gov (United States)

    Canals, Mauricio; Veloso, Claudio; Solís, Rigoberto

    2015-01-01

    Spiders are small arthropods that have colonized terrestrial environments. These impose three main problems: (i) terrestrial habitats have large fluctuations in temperature and humidity; (ii) the internal concentration of water is higher than the external environment in spiders, which exposes them continually to water loss; and (iii) their small body size determines a large surface/volume ratio, affecting energy exchange and influencing the life strategy. In this review we focus on body design, energetic, thermal selection, and water balance characteristics of some spider species present in Chile and correlate our results with ecological and behavioral information. Preferred temperatures and critical temperatures of Chilean spiders vary among species and individuals and may be adjusted by phenotypic plasticity. For example in the mygalomorph high-altitude spider Paraphysa parvula the preferred temperature is similar to that of the lowland spider Grammostola rosea; but while P. parvula shows phenotypic plasticity, G. rosea does not. The araneomorph spiders Loxosceles laeta and Scytodes globula have greater daily variations in preferred temperatures at twilight and during the night, which are set to the nocturnal activity rhythms of these species. They also present acclimation of the minimum critical temperatures. Dysdera crocata has a low preferred temperature adjusted to its favorite prey, the woodlouse. Spider metabolic rate is low compared to other arthropods, which may be associated with its sit and wait predatory strategy particularly in primitive hunter and weavers. In mygalomorph spiders the respiratory system is highly optimized with high oxygen conductance, for example G. rosea needs only a difference of 0.12–0.16 kPa in the oxygen partial pressure across the air-hemolymph barrier to satisfy its resting oxygen consumption demands. Water loss is a significant stress for spiders. Paraphysa parvula shows an evaporative water loss 10 times more than usual

  14. February 27, 2010 Chilean Tsunami in Pacific and its Arrival to North East Asia

    Science.gov (United States)

    Zaytsev, Andrey; Pelinovsky, EfiM.; Yalciner, Ahmet C.; Ozer, Ceren; Chernov, Anton; Kostenko, Irina; Shevchenko, Georgy

    2010-05-01

    The outskirts of the fault plane broken by the strong earthquake on February 27, 2010 in Chili with a magnitude 8.8 at the 35km depth of 35.909°S, 72.733°W coordinates generated a moderate size tsunami. The initial amplitude of the tsunami source is not so high because of the major area of the plane was at land. The tsunami waves propagated far distances in South and North directions to East Asia and Wet America coasts. The waves are also recorded by several gauges in Pacific during its propagation and arrival to coastal areas. The recorded and observed amplitudes of tsunami waves are important for the potential effects with the threatening amplitudes. The event also showed that a moderate size tsunami can be effective even if it propagates far distances in any ocean or a marginal sea. The far east coasts of Russia at North East Asia (Sakhalin, Kuriles, Kamchatka) are one of the important source (i.e. November 15, 2006, Kuril Island Tsunami) and target (i.e. February, 27, 2010 Chilean tsunami) areas of the Pacific tsunamis. Many efforts have been spent for establishment of the monitoring system and assessment of tsunamis and development of the mitigation strategies against tsunamis and other hazards in the region. Development of the computer technologies provided the advances in data collection, transfer, and processing. Furthermore it also contributed new developments in computational tools and made the computer modeling to be an efficient tool in tsunami warning systems. In this study the tsunami numerical model NAMI DANCE Nested version is used. NAMI-DANCE solves Nonlinear form of Long Wave (Shallow water) equations (with or without dispersion) using finite difference model in nested grid domains from the source to target areas in multiprocessor hardware environment. It is applied to 2010 Chilean tsunami and its propagation and coastal behavior at far distances near Sakhalin, Kuril and Kamchatka coasts. The main tide gauge records used in this study are from

  15. Quaternary volcanism in the Acambay graben, Mexican Volcanic Belt: Re-evaluation for potential volcanic danger in central Mexico

    Science.gov (United States)

    Aguirre-Diaz, G. J.; Pedrazzi, D.; Lacan, P.; Roldan-Quintana, J.; Ortuňo, M.; Zuniga, R. R.; Laurence, A.

    2015-12-01

    The Mexican Volcanic Belt (MVB) is best known for the major active stratovolcanoes, such as Popocatépetl, Citlaltépetl and Colima. The most common stratovolcanoes in this province are modest-size cones with heights of 800 to 1000 m. Examples are Tequila, Sangangüey, Las Navajas, Culiacán, La Joya, El Zamorano, Temascalcingo and Altamirano; these last two were formed within the Acambay Graben in central MVB. The Acambay graben (20 x 70 km) is 100 km to the NW of Mexico City, with E-W trending seismically active normal faults; in particular the Acambay-Tixmadejé fault related to a mB =7 earthquake in 1912. Within the graben there are many volcanic structures, including calderas, domes, cinder cones and stratovolcanoes; Temascalcingo and Altamirano are the largest, with about 800 and 900 m heights, respectively. Temascalcingo is mostly composed of dacitic lavas and block and ash flow deposits. Includes a 3 x 2.5 km summit caldera and a magmatic sector collapse event with the associated debris avalanche deposit. 14C ages of 37-12 ka correspond to the volcano's latest phases that produced pyroclastic deposits. A major plinian eruption formed the San Mateo Pumice with an age of <20 Ka. Altamirano volcano is poorly studied; it is andesitic-dacitic, composed of lavas, pyroclastic flow deposits, and pumice fallouts. Morphologically is better preserved than Temascalcingo, and it should be younger. 14C ages of 4.0-2.5 ka were performed in charcoal within pyroclastic flow deposits that apparently were erupted from Altamirano. An undated 3 m thick pumice fallout on the flanks of Altamirano volcano could be also Holocene. It represents a major explosive event. The relatively young ages found in volcanic deposits within the Acambay graben raise the volcanic danger level in this area, originally thought as an inactive volcanic zone. The two major volcanoes, Temascalcingo and Altamirano, should be considered as dormant volcanoes that could restart activity at any time. We

  16. Volcanic Origin of Alkali Halides on Io

    Science.gov (United States)

    Schaefer, L.; Fegley, B., Jr.

    2003-01-01

    The recent observation of NaCl (gas) on Io confirms our earlier prediction that NaCl is produced volcanically. Here we extend our calculations by modeling thermochemical equilibrium of O, S, Li, Na, K, Rb, Cs, F, Cl, Br, and I as a function of temperature and pressure in a Pele-like volcanic gas with O/S/Na/Cl/K = 1.518/1/0.05/0.04/0.005 and CI chondritic ratios of the other (as yet unobserved) alkalis and halogens. For reference, the nominal temperature and pressure for Pele is 1760 plus or minus 210 K and 0.01 bars based on Galileo data and modeling.

  17. Learning to recognize volcanic non-eruptions

    Science.gov (United States)

    Poland, Michael P.

    2010-01-01

    An important goal of volcanology is to answer the questions of when, where, and how a volcano will erupt—in other words, eruption prediction. Generally, eruption predictions are based on insights from monitoring data combined with the history of the volcano. An outstanding example is the A.D. 1980–1986 lava dome growth at Mount St. Helens, Washington (United States). Recognition of a consistent pattern of precursors revealed by geophysical, geological, and geochemical monitoring enabled successful predictions of more than 12 dome-building episodes (Swanson et al., 1983). At volcanic systems that are more complex or poorly understood, probabilistic forecasts can be useful (e.g., Newhall and Hoblitt, 2002; Marzocchi and Woo, 2009). In such cases, the probabilities of different types of volcanic events are quantified, using historical accounts and geological studies of a volcano's past activity, supplemented by information from similar volcanoes elsewhere, combined with contemporary monitoring information.

  18. Volcanic glass - an ideal paleomagnetic recording material?

    OpenAIRE

    Ferk, Annika

    2012-01-01

    Volcanic glass is often considered an ideal recording material for paleointensities. Experiments to determine the ancient field intensity are time consuming and mostly have low success rates. Studies have shown that the usage of glassy samples can increase success rates very much as the remanence carriers are in or close to the single domain range. Further, effects like magnetic anisotropy and cooling rate correction can be corrected for. The aim of this thesis is to clarify whether an ideal ...

  19. Tectonic Controls on Pyroclastic Volcanism on Mercury

    Science.gov (United States)

    Habermann, M.; Klimczak, C.

    2015-12-01

    Over much of Mercury's geologic history the planet has contracted as a response to cooling of its interior. Such contraction is evident as landforms formed by thrust faults, which have accommodated a radius decrease of ~5 km. Stresses from global contraction imposed on the lithosphere are not favorable for and prevent volcanism. Yet, there are examples on Mercury where pyroclastic deposits superpose thrust faults, indicating that explosive volcanism has occurred after the onset of global contraction. To better understand the spatial relationships of thrust faults with the pyroclastic vents, we used MESSENGER image data to categorize 343 vents by their occurrence either (1) within 30 km, (2) within 100 km, or (3) farther than 100 km from a thrust fault, using ArcGIS. Vents were also classified by their association with impact craters. Results show that 75% of all vents are located within impact structures, with 36% of vents within 30 km of thrust faults, 41% located farther than 30 but within 100 km of thrust faults, and 23% of vents are farther than 100 km from a thrust fault. To investigate whether this geospatial relationship is tectonically controlled, three areas —representing the three categories of vents— were mapped, and the locations and orientations of vents and faults were recorded. Stress changes around these faults were then numerically modeled with the COULOMB 3.4 software, using elastic rock properties, a background stress field, and fault size- and dislocation parameters applicable to conditions of Mercury's global contractional tectonic environment. Preliminary results indicate that stress changes can locally produce conditions beneficial for volcanism. Further modeling will determine if such beneficial conditions are geospatially correlated with the pyroclastic vents and thus enable a better understanding of pyroclastic volcanism on Mercury after the onset of global contraction.

  20. Modelling the atmospheric chemistry of volcanic plumes

    OpenAIRE

    Surl, Luke

    2016-01-01

    Abstract Volcanoes are the principal way by which volatiles are transferred from the solid Earth to the atmosphere-hydrosphere system. Once released into the atmosphere, volcanic emissions rapidly undergo a complex series of chemical reactions. This thesis seeks to further the understanding of such processes by both observation and numerical modelling. I have adapted WRF-Chem to model passive degassing from Mount Etna, the chemistry of its plume, and its influence on the ...

  1. Corrosion Properties of a Volcanic Hot Spring

    OpenAIRE

    Lichti, K. L.; Braham, V. J.; Engelberg, D.; Sanada, N.; Kurata, J.; Nanjo, H.; Ikeuchi, J.; Christenson, B.W.

    1998-01-01

    Volcanic hot pools on White Island, New Zealand provide ready access to acidic fluids at atmospheric pressure. These hot pools can be used to study the corrosion properties of construction materials that might be used for energy production from deep-seated and magma-ambient geothermal systems, or from shallow resources producing acidic fluids. corrosion results for a 1,hot pool are presented. A select group of moderate and high alloy materials appear suitable for energy plant applications. Ch...

  2. Minerogenesis of volcanic caves of Kenya.

    Directory of Open Access Journals (Sweden)

    Rossi Antonio

    2003-01-01

    Full Text Available Kenya is one of the few countries in which karst cavities are scarce with respect to volcanic ones, which are widespread throughout the whole country. The great variability in lava composition allowed the evolution of very different cavities, some of which are amongst the largest lava tubes of the world. As normal for such a kind of cave, the hosted speleothems and cave minerals are scarce but important from the minerogenetic point of view. Anyway up to present no specific mineralogical research have been carried out therein. During the 8th International Symposium on Volcanospeleology, held in Nairobi in February 1998, some of the most important volcanic caves of Kenya have been visited and their speleothems and/or chemical deposits sampled: most of them were related to thick guano deposits once present inside these cavities. Speleothems mainly consisted of opal or gypsum, while the deposits related to guano often resulted in a mixture of sulphates and phosphates. The analyses confirmed the great variability in the minerogenetic mechanisms active inside the volcanic caves, which consequently allow the evolution of several different minerals even if the total amount of chemical deposit is scarce. Among the observed minerals kogarkoite, phillipsite and hydroxyapophyllite, must be cited because they are new cave minerals not only for the lava tubes of Kenya, but also for the world cave environment. The achieved results are compared with the available random data from previous literature in order to allow an updated overview on the secondary cave minerals of Kenya.

  3. Venus volcanism: initial analysis from magellan data.

    Science.gov (United States)

    Head, J W; Campbell, D B; Elachi, C; Guest, J E; McKenzie, D P; Saunders, R S; Schaber, G G; Schubert, G

    1991-04-12

    Magellan images confirm that volcanism is widespread and has been fimdamentally important in the formation and evolution of the crust of Venus. High-resolution imaging data reveal evidence for intrusion (dike formation and cryptodomes) and extrusion (a wide range of lava flows). Also observed are thousands of small shield volcanoes, larger edifices up to several hundred kilometers in diameter, massive outpourings of lavas, and local pyroclastic deposits. Although most features are consistent with basaltic compositions, a number of large pancake-like domes are morphologically similar to rhyolite-dacite domes on Earth. Flows and sinuous channels with lengths of many hundreds of kilometers suggest that extremely high effusion rates or very fluid magmas (perhaps komatiites) may be present. Volcanism is evident in various tectonic settings (coronae, linear extensional and compressional zones, mountain belts, upland rises, highland plateaus, and tesserae). Volcanic resurfacing rates appear to be low (less than 2 Km(3)/yr) but the significance of dike formation and intrusions, and the mode of crustal formation and loss remain to be established.

  4. Tracing acidification induced by Deccan volcanism

    Science.gov (United States)

    Font, Eric; Adatte, Thierry; Fantasia, Alicia; Ponte, Jorge; Florindo, Fabio; Abrajevitch, Alexandra; Samant, Bandana; Mohabey, Dhananjay; Thakre, Deepali

    2015-04-01

    The Deccan Volcanic Province (DVP) is constituted by three major phases of eruptions, for which the most voluminous - the Deccan Phase-2 - encompassed the Cretaceous-Paleogene (KT) boundary and has been pointed as the main contributor of the KT mass extinction. However, the mechanisms (including acidification) by which the massive Deccan Phase eruptions contributed to the end-Cretaceous global changes and to the controversial KT mass extinction are still poorly constrained. Here we identify the regional climate and environmental effects of the Deccan eruptions by studying the magnetic and mineral assemblages preserved in the lacustrine and continental intertrappeans sediments from the western Maharashtra Deccan Volcanic Provinces (DVP). To achieve this objective, we applied rock magnetic techniques coupled to scanning electron microscopy and diffuse reflectance spectrophotometry to samples collected in three different stratigraphic sections. Our results show that the main magnetic carriers of the Deccan lacustrine and continental sediments are represented by allogenic (detrital) magnetite and hematite inherited from the weathering of the surrounding underlying basaltic bedrocks. Iron sulphides (pyrrhotite or greigite) are accessorily observed. Interestingly, the Podgawan deposits show peculiar and very distinct magnetic and mineralogical signatures, including iron oxide reductive dissolution and widespread crystallisation of iron vanadates, that we interpreted as the effect of Deccan induced acidification. Keywords: Deccan Volcanic Province, intertrappean continental sediments, environmental magnetism Funded by FCT (PTDC/CTE-GIX/117298/2010)

  5. Venus volcanism: Initial analysis from Magellan data

    Science.gov (United States)

    Head, J.W.; Campbell, D.B.; Elachi, C.; Guest, J.E.; Mckenzie, D.P.; Saunders, R.S.; Schaber, G.G.; Schubert, G.

    1991-01-01

    Magellan images confirm that volcanism is widespread and has been fundamentally important in the formation and evolution of the crust of Venus. High-resolution imaging data reveal evidence for intrusion (dike formation and cryptodomes) and extrusion (a wide range of lava flows). Also observed are thousands of small shield volcanoes, larger edifices up to several hundred kilometers in diameter, massive outpourings of lavas, and local pyroclastic deposits. Although most features are consistent with basaltic compositions, a number of large pancake-like domes are morphologically similar to rhyolite-dacite domes on Earth. Flows and sinuous channels with lengths of many hundreds of kilometers suggest that extremely high effusion rates or very fluid magmas (perhaps komatiites) may be present. Volcanism is evident in various tectonic settings (coronae, linear extensional and compressional zones, mountain belts, upland rises, highland plateaus, and tesserae). Volcanic resurfacing rates appear to be low (less than 2 km3/yr) but the significance of dike formation and intrusions, and the mode of crustal formation and loss remain to be established.

  6. A probabilistic approach to determine volcanic eruption centres of degraded volcanic edifices

    Science.gov (United States)

    Székely, B.; Karátson, D.

    2009-04-01

    It is often a difficult problem to determine the position of original eruption centres of degraded volcanic edifices. Beside of the destructive processes acting during the volcanic activity, subsequent erosion, mass movements and tectonic motions modify the spatial distribution of the volcanic features. The observations including dipping strata, clast orientations, lava flows, etc. made on the present surface are therefore biased by the post-eruptive processes making the reconstruction of the original volcanic pattern problematic. The different types of observations and their various error levels complicate the problem further. We propose a probabilistic approach to evaluate the different types of observations. Each observation type or even each observation may have their own error bars which can be taken into account in this scheme. The only assumption is that it is possible to determine the relative direction of the original volcanic centre based on the specific observation within a given angular accuracy. In our scheme a spatial probability density function (PDF) is assigned to each observation and the weighted sum of these PDFs results in a map. This integrated PDF map then can be evaluated to determine one or multiple eruption centres. In case of multiple centres further decision can be made on whether the various centres are only virtual, caused by subsequent tectonism or, on the contrary, the original setting had several eruption vents. This decision can be made on targeted grouping of PDFs of different types of observations or spatial selection. The resulting compound PDF maps may outline individual centres.

  7. Neogene volcanism in Gutai Mts. (Eastern Carpathains: a review

    Directory of Open Access Journals (Sweden)

    Marinel Kovacs

    2003-04-01

    Full Text Available Two types of volcanism developed in Gutâi Mts. (inner volcanic chain of Eastern Carpathians: a felsic, extensional/“back-arc” type and an intermediate, arc type. The felsic volcanism of explosive origin, consisting of caldera-related rhyolitic ignimbrites and resedimented volcaniclastics, had taken place during Early-Middle Badenian and Early Sarmatian. The intermediate volcanism, consisting of extrusive (effusive and explosive and intrusive activity, had developed during Sarmatian and Pannonian (13.4-7.0 Ma. It is represented by typical calc-alkaline series, from basalts to rhyolites. Lava flows of basaltic andesites and andesites are predominant, often emplaced in subaqueous environment. Extrusive domes, mainly composed of dacites, are associated to the andesitic volcanic structures. The intermediate volcanism, consisting of extrusive (effusive and explosive and intrusive activity, had developed during Sarmatian and Pannonian (13.4-7.0 Ma. It is represented by typical calc-alkaline series, from basalts to rhyolites. Lava flows of basaltic andesites and andesites are predominant, often emplaced in subaqueous environment. Extrusive domes, mainly composed of dacites, are associated to the andesitic volcanic structures. The geochemical study on the volcanic rocks shows the calc-alkaline character of both felsic and intermediate volcanism and typical subduction zones geochemical signatures for the intermediate one. The felsic volcanism shows affinities with subduction-related rocks as well. The main petrogenetic process in Gutâi Mts. was crustal assimilation, strongly constrained by trace element and isotope geochemistry.

  8. Global volcanic emissions: budgets, plume chemistry and impacts

    Science.gov (United States)

    Mather, T. A.

    2012-12-01

    Over the past few decades our understanding of global volcanic degassing budgets, plume chemistry and the impacts of volcanic emissions on our atmosphere and environment has been revolutionized. Global volcanic emissions budgets are needed if we are to make effective use of regional and global atmospheric models in order to understand the consequences of volcanic degassing on global environmental evolution. Traditionally volcanic SO2 budgets have been the best constrained but recent efforts have seen improvements in the quantification of the budgets of other environmentally important chemical species such as CO2, the halogens (including Br and I) and trace metals (including measurements relevant to trace metal atmospheric lifetimes and bioavailability). Recent measurements of reactive trace gas species in volcanic plumes have offered intriguing hints at the chemistry occurring in the hot environment at volcanic vents and during electrical discharges in ash-rich volcanic plumes. These reactive trace species have important consequences for gas plume chemistry and impacts, for example, in terms of the global fixed nitrogen budget, volcanically induced ozone destruction and particle fluxes to the atmosphere. Volcanically initiated atmospheric chemistry was likely to have been particularly important before biological (and latterly anthropogenic) processes started to dominate many geochemical cycles, with important consequences in terms of the evolution of the nitrogen cycle and the role of particles in modulating the Earth's climate. There are still many challenges and open questions to be addressed in this fascinating area of science.

  9. Impact of reproductive laws on maternal mortality: the chilean natural experiment.

    Science.gov (United States)

    Koch, Elard

    2013-05-01

    Improving maternal health and decreasing morbidity and mortality due to induced abortion are key endeavors in developing countries. One of the most controversial subjects surrounding interventions to improve maternal health is the effect of abortion laws. Chile offers a natural laboratory to perform an investigation on the determinants influencing maternal health in a large parallel time-series of maternal deaths, analyzing health and socioeconomic indicators, and legislative policies including abortion banning in 1989. Interestingly, abortion restriction in Chile was not associated with an increase in overall maternal mortality or with abortion deaths and total number of abortions. Contrary to the notion proposing a negative impact of restrictive abortion laws on maternal health, the abortion mortality ratio did not increase after the abortion ban in Chile. Rather, it decreased over 96 percent, from 10.8 to 0.39 per 100,000 live births. Thus, the Chilean natural experiment provides for the first time, strong evidence supporting the hypothesis that legalization of abortion is unnecessary to improve maternal health in Latin America.

  10. Evaluating a NoSQL Alternative for Chilean Virtual Observatory Services

    Science.gov (United States)

    Antognini, J.; Araya, M.; Solar, M.; Valenzuela, C.; Lira, F.

    2015-09-01

    Currently, the standards and protocols for data access in the Virtual Observatory architecture (DAL) are generally implemented with relational databases based on SQL. In particular, the Astronomical Data Query Language (ADQL), language used by IVOA to represent queries to VO services, was created to satisfy the different data access protocols, such as Simple Cone Search. ADQL is based in SQL92, and has extra functionality implemented using PgSphere. An emergent alternative to SQL are the so called NoSQL databases, which can be classified in several categories such as Column, Document, Key-Value, Graph, Object, etc.; each one recommended for different scenarios. Within their notable characteristics we can find: schema-free, easy replication support, simple API, Big Data, etc. The Chilean Virtual Observatory (ChiVO) is developing a functional prototype based on the IVOA architecture, with the following relevant factors: Performance, Scalability, Flexibility, Complexity, and Functionality. Currently, it's very difficult to compare these factors, due to a lack of alternatives. The objective of this paper is to compare NoSQL alternatives with SQL through the implementation of a Web API REST that satisfies ChiVO's needs: a SESAME-style name resolver for the data from ALMA. Therefore, we propose a test scenario by configuring a NoSQL database with data from different sources and evaluating the feasibility of creating a Simple Cone Search service and its performance. This comparison will allow to pave the way for the application of Big Data databases in the Virtual Observatory.

  11. [Antecedents for the teaching of nutrition in the Chilean school system].

    Science.gov (United States)

    Olivares, S; Valiente, S

    1983-01-01

    This article reports that as part of the research into the Chilean population's understanding, habits, and beliefs about food and analysis was made of food and nutrition knowledge in a sample of 966 elementary and secondary school teachers and 1,050 freshmen students of different schools of the University of Chile in 1979, located in three cities in the north, center, and south of the country. Their knowledge of food and nutrition was tested using a standardized questionnaire. The results of the test were graded according to the percentage of correct answers in six categories. Only 30.6 per cent of the teachers and 17 per cent of the students scored above the acceptable minimum of 50 per cent. It is evident that food and nutrition knowledge of elementary and secondary school teachers and of freshmen students at the University of Chile is insufficient. The relationship between the knowledge variable and other variables in the study shows that this lack is mainly related to environmental factors, independent of formal education. The article offers specific suggestions to be incorporated in the nutrition education curriculum in Chile.

  12. Postnatal Growth Patterns in a Chilean Cohort: The Role of SES and Family Environment

    Directory of Open Access Journals (Sweden)

    D. E. Kang Sim

    2012-01-01

    Full Text Available Objective. This study examined how family environmental characteristics served as mediators in the relationship between socioeconomic conditions and infant growth in a cohort of Chilean infants. Methods. We studied 999 infants, born between 1991 and 1996, from a longitudinal cohort which began as an iron deficiency anemia preventive trial. SES (Graffar Index, the Life Experiences Survey, and the Home Observation for Measurement of the Environment (HOME were assessed in infancy. Using path analysis, we assessed the relationships between the social factors, home environment, and infant growth. Results. During the first year, weight and length gain averaged 540 grams/month and 6.5 cm/month, respectively. In the path analysis model for weight gain, higher SES and a better physical environment were positively related to higher maternal warmth, which in turn was associated with higher average weight gain. Higher SES was directly related to higher average length gain. Conclusions. In our cohort, a direct relationship between SES and length gain developed during infancy. Higher SES was indirectly related to infant weight gain through the home environment and maternal warmth. As the fastest growing infants are at risk for later obesity, new strategies are needed to encourage optimal rather than maximal growth.

  13. Chilenopeptins A and B, Peptaibols from the Chilean Sepedonium aff. chalcipori KSH 883.

    Science.gov (United States)

    Otto, Alexander; Laub, Annegret; Wendt, Lucile; Porzel, Andrea; Schmidt, Jürgen; Palfner, Götz; Becerra, José; Krüger, Dirk; Stadler, Marc; Wessjohann, Ludger; Westermann, Bernhard; Arnold, Norbert

    2016-04-22

    The Chilean Sepedonium aff. chalcipori strain KSH 883, isolated from the endemic Boletus loyo Philippi, was studied in a polythetic approach based on chemical, molecular, and biological data. A taxonomic study of the strain using molecular data of the ITS, EF1-α, and RPB2 barcoding genes confirmed the position of the isolated strain within the S. chalcipori clade, but also suggested the separation of this clade into three different species. Two new linear 15-residue peptaibols, named chilenopeptins A (1) and B (2), together with the known peptaibols tylopeptins A (3) and B (4) were isolated from the semisolid culture of strain KSH 883. The structures of 1 and 2 were elucidated on the basis of HRESIMS(n) experiments in conjunction with comprehensive 1D and 2D NMR analysis. Thus, the sequence of chilenopeptin A (1) was identified as Ac-Aib(1)-Ser(2)-Trp(3)-Aib(4)-Pro(5)-Leu(6)-Aib(7)-Aib(8)-Gln(9)-Aib(10)-Aib(11)-Gln(12)-Aib(13)-Leu(14)-Pheol(15), while chilenopeptin B (2) differs from 1 by the replacement of Trp(3) by Phe(3). Additionally, the total synthesis of 1 and 2 was accomplished by a solid-phase approach, confirming the absolute configuration of all chiral amino acids as l. Both the chilenopeptins (1 and 2) and tylopeptins (3 and 4) were evaluated for their potential to inhibit the growth of phytopathogenic organisms. PMID:26953507

  14. Interactions Between the Chilean Recluse Spider (Araneae: Sicariidae) and an Araneophagic Spitting Spider (Araneae: Scytodidae).

    Science.gov (United States)

    Canals, Mauricio; Arriagada, Nicolás; Solís, Rigoberto

    2015-03-01

    In Chile, all necrotic arachnidism is attributed to the Chilean recluse spider, Loxosceles laeta Nicolet, a species that shares the microenvironmental habitats with the spitting spider Scytodes globula Nicolet. The latter species has been proposed as a potential predator of L. laeta. For this research, we studied the interaction between both species during individual encounters to assess the possibility of population regulation of L. laeta cohorts exposed to this potential predator. We found that in most encounters S. globula prevailed. Also, S. globula preys on spiderlings of L. laeta, with a population effect on cohorts of this species. These findings suggest that S. globula may be influencing L. laeta populations in central Chile. The population regulation of L. laeta by predation would be important because this species, in the absence of predators, has a high reproductive rate, and it can maintain populations of large size. However according to our results, although S. globula may aid in the reduction of both spiderling and adult L. laeta populations, and perhaps other Loxosceles species, it is insufficient for biological control of Loxosceles species. Its presence together with other control measures such as hygiene of the rooms can help to decrease loxoscelism incidence. PMID:26336293

  15. Recirculation of Chilean copper smelting dust with high impurities contents to the smelting process

    Energy Technology Data Exchange (ETDEWEB)

    Sano, H.; Fujisawa, T. [Nagoya Univ., Nagoya (Japan). EcoTopia Science Inst.; Montenegro, V. [Nagoya Univ., Nagoya (Japan). Dept. of Materials Science and Engineering

    2007-07-01

    Dust generated during the copper smelting process is generally stabilized using hydrometallurgical methods as it contains high concentrations of arsenic. In this laboratory study, dust was recirculated during the smelting process in order to recover more copper and decrease dust emissions while recovering more copper. The behaviour of impurities and their influence on matte quality was also investigated. Industrial matte, flue dust, slag, and copper concentrates from a Chilean smelter were used as test materials. Dust recirculation tests were conducted in a simulated electric furnace. Off-gases were collected in a reaction tube, and the condensed volatile matter, slag, and matte phases were analyzed for their elemental content by inductively coupled plasma atomic emission spectrometry. The distribution of arsenic (As); antimony (Sb), bismuth (Bi), lead (Pb), and zinc (Zn) were investigated by varying the amounts of dust recirculating to the smelting stage with 21 per cent of the oxygen. Results showed that distributions of all analyzed elements increased with recirculation. It was concluded that copper can be recovered using the dust recirculation technique. However, impurities may limit the efficacy of the dust recirculation process. 6 refs., 3 tabs., 4 figs.

  16. The absence of stewardship in the Chilean health authority after the 2004 health reform

    Directory of Open Access Journals (Sweden)

    Tania Herrera

    2014-11-01

    Full Text Available Stewardship is the most important political function of a health system. It is a government responsibility carried out by the health authority. Among other dimensions, it is also a meta-function that includes conduction and regulation. The Health Authority and Management Act, which came about from the health reform of 2004, separated the functions of service provision and stewardship with the aim of strengthening the role of the health authority. However, the current structure of the health system contains overlapping functions between the different entities that leads to lack of coordination and inconsistencies, and a greater weight on individual health actions at the expense of collective ones. Consequently, a properly funded national health strategy to improve the health of the population is missing. Additionally, the components of citizen participation and governance are weak. It is necessary, therefore, to revisit the Chilean health structure in order to develop one that truly enables the exercise of the health authority’s stewardship role

  17. Cladistic analysis and description of three new species of the Chilean genus Nanophareus (Opiliones: Gonyleptidae: Pachylinae).

    Science.gov (United States)

    Hara, Marcos Ryotaro

    2016-01-01

    Three new species of the Chilean Pachylinae genus, Nanophareus Roewer, 1929 are described: N. bicornutus sp. nov. (Valle de Aconcagua, Zapallar, V Región de Valparaíso), N. maipu sp. nov. (La Rinconada, Quebrada de la Plata, Maipu, Región Metropolitana-Santiago), and N. polyhastatus sp. nov. (El Abanico, VIII Región de Bio-Bío). These three new species were included in a cladistic analysis that resulted in two equally most parsimonious trees (238 steps, C.I. = 0.38; R.I. = 0.51), corroborating the monophyly of Nanophareus. The proposed synapomorphies for Nanophareus remain largely unchanged: an external row of enlarged tubercles inserted amongst small ones on the lateral margin of dorsal scutum; the ventro-basal margin of the pedipalpal tibia curved at 90° in lateral view; and retrolateral seta on pedipalpal tibia with an apically bifid socket (socket and seta longer than pedipalpal tibia length), with additional small setae distally. The sister group of Nanophareus, as well as its subfamilial placement, are still unsettled issues that are here further discussed.

  18. [Prevalence of deficiency and dietary intake of iron, zinc and copper in Chilean childbearing age women].

    Science.gov (United States)

    Mujica-Coopman, María F; Borja, Angélica; Pizarro, Fernando; Olivares, Manuel

    2014-03-01

    The aim of the present study was to evaluate anemia, the biochemical status and dietary adequacy of iron (Fe), zinc (Zn) and copper (Cu), in Chilean childbearing age women. We studied a convenience sample of 86 women aged 18 to 48 years from Santiago, Chile. We determined anemia and the micronutrient status through hemoglobin (Hb) mean corpuscular volume, transferrin saturation, zinc protoporphyrin, serum ferritin (SF), serum Zn and Cu. Dietary adequacy was estimated using a food frequency questionnaire. Of all women, 4.7% had Fe deficiency (ID) anemia, 21 % ID without anemia, 26 % depleted Fe stores and 48.3% normal Fe status. Obese women had higher SF (p<0.01) compared with those classified as having normal BMI. Also, showed higher Hb (p<0.05) concentrations compared with overweight and normal weight women. Partidipants showed 3.5 % and 2.3 % of Zn and Cu deficiency, respectively. Also, 95 %, 94 % and 99 % had adequate intake of Fe, Zn and Cu respectively, according to EAR cut points. There were no significant differences in micronutrients intake across different nutritional status. There was a low prevalence of anemia, Fe, Zn and Cu deficiency. A high percentage of women reached micronutrient adequacy. However, 47% of women had ID without anemia and Fe depleted stores.

  19. Gps mutations in Chilean patients harboring growth hormone-secreting pituitary tumors.

    Science.gov (United States)

    Johnson, M C; Codner, E; Eggers, M; Mosso, L; Rodriguez, J A; Cassorla, F

    1999-01-01

    Hypersecretion of GH is usually caused by a pituitary adenoma and about 40% of these tumors exhibit missense gsp mutations in Arg201 or Gln227 of the Gs, gene. We studied 20 pituitary tumors obtained from patients with GH hypersecretion. One tumor was resected from an 11 year-old boy with a 3 year history of accelerated growth, associated with increased concentrations of serum GH and IGF-I, which were not suppressed by glucose administration. The remaining 19 tumors were obtained from adult acromegalic patients, who had elevated baseline serum GH levels that did not show evidence of suppression after administration of glucose. The gsp mutations were studied by enzymatic digestion of the amplified PCR fragment of exon 8 (Arg201) and exon 9 (Gln227) with the enzymes NlaIII and NgoAIV, respectively. The tumors obtained from the boy and from nine of the 19 patients with acromegaly exhibited the gsp mutation R201H. None of the tumors had the Gln227 mutation. The gsp positive patients tended to be older, had smaller tumors, and had preoperative basal serum GH levels which were significantly lower (21 +/- 6 vs 56 +/- 16 microg/l, pgigantism and in approximately half of 19 Chilean adult patients with acromegaly, similar to other populations. PMID:10821217

  20. Unique clusters of Archaea in Salar de Huasco, an athalassohaline evaporitic basin of the Chilean Altiplano.

    Science.gov (United States)

    Dorador, Cristina; Vila, Irma; Remonsellez, Francisco; Imhoff, Johannes F; Witzel, Karl-Paul

    2010-08-01

    Analyses of clone libraries from water and sediments of different sites from Salar de Huasco, a high-altitude athalassohaline wetland in the Chilean Altiplano, revealed the presence of five unique clusters of uncultured Archaea that have not been previously reported or specifically assigned. These sequences were distantly related (83-96% sequence identity) to a limited number of other clone sequences and revealed no identity to cultured Archaea. The abundance of Archaea and Bacteria was estimated using qPCR and community composition was examined through the construction of clone libraries of archaeal 16S rRNA gene. Archaea were found to be dominant over Bacteria in sediments from two saline sites (sites H4: 6.31 x 10(4) and site H6: 1.37 x 10(4) microS cm(-1)) and in one of the water samples (freshwater from site H0: 607 muS cm(-1)). Euryarchaeotal sequences were more abundant than crenarchaeotal sequences. Many of the clone sequences (52%) were similar to uncultured archaeal groups found in marine ecosystems having identity values between 99% and 97%. A major fraction of the sequences (40%) were members of Methanobacteria, while others were included in the Marine Benthic Groups B and D, the Miscellaneous Crenarchaeotic Group, the Terrestrial Miscellaneous Euryarchaeotal Group, Marine Group I and Halobacteria. The presence of uncultured archaeal groups in Salar de Huasco extends their known distribution in inland waters, providing new clues about their possible function in the environment.