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Sample records for chilean volcanic soils

  1. High rates of nitrogen cycling in volcanic soils from Chilean grasslands.

    Science.gov (United States)

    Dixon, E R; Cardenas, L; Alfaro, M; Salazar, F; Hatch, D J

    2011-06-15

    There are over one million hectares of pasture in Chile, and 80% and 50% of the country's milk and meat comes from 72% of this area, situated in the lake region of southern Chile. The soils are volcanic and a major characteristic is that they have very high organic matter (OM) contents with the potential to support plant growth with only moderate levels of added nitrogen (N). To understand better the potential fertility of these soils in order to maximise production and minimise losses of N, we undertook studies using the stable isotope of N ((15)N) to resolve the rates of the main internal N cycling processes in three soils representing the two main volcanic soil types: Osorno and Chiloé (Andisol) and Cudico (Ultisol). We also assessed the longer-term potential of these soils to sustain N release using anaerobic incubation. Gross rates (µg N g(-1) day(-1)) of mineralisation were 27.9, 27.1 and 15.5 and rates of immobilisation were 5.9, 12.0 and 6.3 for Osorno, Chiloé and Cudico, respectively, implying high rates of net mineralisation in these soils. This was confirmed by anaerobic incubation which gave potential seasonal net mineralisation indices of 1225, 1059 and 450 kg N ha(-1) in the top 10 cm soil layers of the three soils. However, plant production may still benefit from added N, as the release of N from organic sources may not be closely synchronised with crop demand. The low rates of nitrification that we found with these acidic soils suggest that the more mobile N (viz. nitrate-N) would be in limited supply and plants would have to compete for the less mobile ammonium-N with the soil microbial biomass. Nitrogen was mineralised in appreciable amounts even down to 60 cm depth, so that leaching could become significant, particularly if the soils were limed, which could enhance nitrification and N mobility through the soil profile. PMID:21594925

  2. Comparative study of P uptake and utilization from P fertilizers by Chilean wheat genotypes in volcanic ash soils

    International Nuclear Information System (INIS)

    The intensification of the agricultural production in Southern Chile demand the application of P fertilizers to volcanic ash soils for optimum plant growth and crop yields. Due to the high P sorption capacities of these soils, high amounts of water-soluble phosphatic fertilizers need to be applied. Therefore, the direct application of locally available Bahia Inglesa phosphate rock has been utilized to supply P to crops in these acid soils. Phosphate rock is a very efficient P input for crops with long growth cycles or crop rotations nevertheless water-soluble P fertilizers must still be applied to crops of short growth cycle. Combined with these strategic P inputs, the use of acid-tolerant and P-efficient genotypes can further contribute to agricultural sustainability. Greenhouse studies were undertaken to explore and identify genotypic variations in P efficiency of wheat grown in Andisols of Southern Chile. 32P isotopic techniques were utilized to measure the uptake of P from triple superphosphate, a water-soluble P fertilizer and the locally available Bahia Inglesa phosphate rock. Substantial genotypic variations in P use efficiency were found among the Chilean wheat genotypes tested. The utilization of the 32P isotopic techniques enabled to quantify the P taken up from the P fertilizer and the assessment of differences among the genotypes. Significant genotypic differences were obtained in the P uptake from the local phosphate rock Bahia Inglesa. Much higher applications of phosphate rock were required in Santa Barbara soil series (Andisol) due to its high P retention. A sustainable strategy for agricultural production in the Andisols of Chile would therefore, be the combined utilization of those efficient wheat genotypes and the local phosphate rock Bahia Inglesa. As P efficiency is a multi-faceted trait, which interacts with a range of environmental factors, further field-testing and validation is required accompanied by in depth studies to assess the relative

  3. 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.

  4. Diversity and activity of denitrifiers of Chilean arid soil ecosystems

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    GescheBraker

    2012-04-01

    Full Text Available The Chilean sclerophyllous matorral is a Mediterranean semiarid ecosystem affected by erosion, with low soil fertility and limited by nitrogen. However, limitation of resources is even more severe for desert soils such as from the Atacama Desert, one of the most extreme arid deserts on Earth. Topsoil organic matter, nitrogen and moisture content were significantly higher in the semiarid soil compared to the desert soil. Although the most significant loss of biologically preferred nitrogen from terrestrial ecosystems occurs via denitrification, virtually nothing is known on the activity and composition of denitrifier communities thriving in arid soils. In this study, we explored denitrifier communities from two soils with profoundly distinct edaphic factors. While denitrification activity in the desert soil was below detection limit, the semiarid soil sustained denitrification activity. To elucidate the genetic potential of the soils to sustain denitrification processes we performed community analysis of denitrifiers based on nitrite reductase (nirK and nirS genes as functional marker genes for this physiological group. Presence of nirK-type denitrifiers in both soils was demonstrated but failure to amplify nirS from the desert soil suggests very low abundance of nirS-type denitrifiers shedding light on the lack of denitrification activity. Phylogenetic analysis showed a very low diversity of nirK with only three distinct genotypes in the desert soil which conditions presumably exert a high selection pressure. While nirK diversity was also limited to only few, albeit distinct genotypes, the semiarid matorral soil showed a surprisingly broad genetic variability of the nirS gene. The Chilean matorral is a shrub land plant community which form vegetational patches stabilizing the soil and increasing its nitrogen and carbon content. These islands of fertility may sustain the development and activity of the overall microbial community and of

  5. Soil properties controlling infiltration in volcanic soils

    Science.gov (United States)

    Neris, Jonay; Tejedor, Marisa; Jiménez, Concepción

    2013-04-01

    Soil water infiltration is an important process whose behaviour depends on external factors and soil properties that vary depending on the type of soil. The soil parameters affecting the infiltration capacity of six soil orders all formed on volcanic materials (andisols, vertisols, alfisols, aridisols, inceptisols, and entisols) and contribute to the differences between them were studied in this paper. A total of 108 sites were selected on the island of Tenerife (Spain). The main soil properties were analysed and the steady-state infiltration rate measured using a double-ring infiltrometer. The relationship between the soil properties and infiltration was modelled using statistical Principal Components Analysis and regressions. The research concludes that the relation between structural development and texture play a decisive role. The high structural development of non-vitric andisols, due to the high organic matter and short-range-order mineral content, leads to an extremely fast infiltration rate. The structural instability and fine texture of aridisols produce low infiltration. In less developed soils (entisols and vitric andisols) where aggregate formation is minimal or non-existent, the coarse grain size is the relevant factor determining their very fast and extremely fast infiltration. In vertisols and alfisols, which have strong aggregation but low stability, clay type and content play an important role and lead to a moderate and moderately fast steady-state infiltration rate, respectively. In the most typic inceptisols, with moderate structural development and stability, the balance of the properties is largely responsible for the intermediate infiltration rate observed.

  6. Aggregate and soil organic carbon dynamics in South Chilean Andisols

    Science.gov (United States)

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

    2005-06-01

    Extreme sensitivity of soil organic carbon (SOC) to climate and land use change warrants further research in different terrestrial ecosystems. The aim of this study was to investigate the link between aggregate and SOC dynamics in a chronosequence of three different land uses of a south Chilean Andisol: a second growth Nothofagus obliqua forest (SGFOR), a grassland (GRASS) and a Pinus radiata plantation (PINUS). Total carbon content of the 0-10cm soil layer was higher for GRASS (6.7 kg C m-2) than for PINUS (4.3 kg C m-2, while TC content of SGFOR (5.8 kg C m-2) was not significantly different from either one. High extractable oxalate and pyrophosphate Al concentrations (varying from 20.3-24.4 g kg-1, and 3.9-11.1 g kg-1, respectively) were found in all sites. In this study, SOC and aggregate dynamics were studied using size and density fractionation experiments of the SOC, δ13C and total carbon analysis of the different SOC fractions, and C mineralization experiments. The results showed that electrostatic sorption between and among amorphous Al components and clay minerals is mainly responsible for the formation of metal-humus-clay complexes and the stabilization of soil aggregates. The process of ligand exchange between SOC and Al would be of minor importance resulting in the absence of aggregate hierarchy in this soil type. Whole soil C mineralization rate constants were highest for SGFOR and PINUS, followed by GRASS (respectively 0.495, 0.266 and 0.196 g CO2-Cm-2d-1 for the top soil layer). In contrast, incubation experiments of isolated macro organic matter fractions gave opposite results, showing that the recalcitrance of the SOC decreased in another order: PINUS>SGFOR>GRASS. We deduced that electrostatic sorption processes and physical protection of SOC in soil aggregates were the main processes determining SOC stabilization. As a result, high aggregate carbon concentrations, varying from 148 till 48 g kg-1, were encountered for all land use sites. Al

  7. Aggregate and soil organic carbon dynamics in South Chilean Andisols

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    D. Huygens

    2005-01-01

    Full Text Available Extreme sensitivity of soil organic carbon (SOC to climate and land use change warrants further research in different terrestrial ecosystems. The aim of this study was to investigate the link between aggregate and SOC dynamics in a chronosequence of three different land uses of a south Chilean Andisol: a second growth Nothofagus obliqua forest (SGFOR, a grassland (GRASS and a Pinus radiata plantation (PINUS. Total carbon content of the 0-10cm soil layer was higher for GRASS (6.7 kg C m-2 than for PINUS (4.3 kg C m-2, while TC content of SGFOR (5.8 kg C m-2 was not significantly different from either one. High extractable oxalate and pyrophosphate Al concentrations (varying from 20.3-24.4 g kg-1, and 3.9-11.1 g kg-1, respectively were found in all sites. In this study, SOC and aggregate dynamics were studied using size and density fractionation experiments of the SOC, δ13C and total carbon analysis of the different SOC fractions, and C mineralization experiments. The results showed that electrostatic sorption between and among amorphous Al components and clay minerals is mainly responsible for the formation of metal-humus-clay complexes and the stabilization of soil aggregates. The process of ligand exchange between SOC and Al would be of minor importance resulting in the absence of aggregate hierarchy in this soil type. Whole soil C mineralization rate constants were highest for SGFOR and PINUS, followed by GRASS (respectively 0.495, 0.266 and 0.196 g CO2-Cm-2d-1 for the top soil layer. In contrast, incubation experiments of isolated macro organic matter fractions gave opposite results, showing that the recalcitrance of the SOC decreased in another order: PINUS>SGFOR>GRASS. We deduced that electrostatic sorption processes and physical protection of SOC in soil aggregates were the main processes determining SOC stabilization. As a result, high aggregate carbon concentrations, varying from 148 till 48 g kg-1, were encountered for all land use

  8. Tropical Volcanic Soils From Flores Island, Indonesia

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    Hikmatullah

    2010-01-01

    Full Text Available Soils that are developed intropical region with volcanic parent materials have many unique properties, and high potential for agricultural use.The purpose of this study is to characterize the soils developed on volcanic materials from Flores Island, Indonesia,and to examine if the soils meet the requirements for andic soil properties. Selected five soils profiles developed fromandesitic volcanic materials from Flores Island were studied to determine their properties. They were compared intheir physical, chemical and mineralogical characteristics according to their parent material, and climatic characteristicdifferent. The soils were developed under humid tropical climate with ustic to udic soil moisture regimes withdifferent annual rainfall. The soils developed from volcanic ash parent materials in Flores Island showed differentproperties compared to the soils derived from volcanic tuff, even though they were developed from the sameintermediary volcanic materials. The silica contents, clay mineralogy and sand fractions, were shown as the differences.The different in climatic conditions developed similar properties such as deep solum, dark color, medium texture, andvery friable soil consistency. The soils have high organic materials, slightly acid to acid, low to medium cationexchange capacity (CEC. The soils in western region have higher clay content and showing more developed than ofthe eastern region. All the profiles meet the requirements for andic soil properties, and classified as Andisols order.The composition of sand mineral was dominated by hornblende, augite, and hypersthenes with high weatherablemineral reserves, while the clay fraction was dominated by disordered kaolinite, and hydrated halloysite. The soilswere classified into subgroup as Thaptic Hapludands, Typic Hapludands, and Dystric Haplustands

  9. Non-volcanic andic soils - a new soil type?

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    Bäumler, Rupert

    2014-05-01

    Numerous sites are described all over the world with soils fulfilling all requirements of andic soil properties developed in non-volcanic and non-allophanic parent materials, and in different bioclimatic zones. Up to now these soils are mainly assigned to Andisols/Andosols or andic Inceptisols in WRB and US Soil Taxonomy. Common factors and properties of this group of soils are in general acid parent materials, advanced soil development, comparably high amounts of oxidic Fe and Al compounds, leaching environment, and a probably underestimated role of iron with respect to the specific soil properties, e.g. extremely stabile, pseudo-sand like micro-aggregates. Considering the worldwide occurrence of these soils and the specificity of their physicochemical properties, I suggest soil forming processes and a new soil type clearly different from Andosols/Andisols in a narrow sense.

  10. Iron Oxides from Volcanic Soils as Potential Catalysts in the Water Gas Shift Reaction

    International Nuclear Information System (INIS)

    This study was focused on changes of the iron oxide mineralogy with temperature of two Chilean soils (Andisol and Ultisol) derived from volcanic materials and their use as iron-based catalysts in the water gas shift reaction (WGSR). Ultisol materials produced about twice as much hydrogen than did those from Andisol upon WGSR, but in both cases hydrogen yielding increased as the heating temperature of the soil materials increased from 124 deg. C to 500 deg. C. The room temperature Moessbauer spectra showed an increase of the relative proportion of the magnetically ordered components as temperature increased. Higher heating temperature produced a negative effect on the catalytic activity, whereas the organic matter destruction led to a positive effect, due to an increasing exposition of the iron oxide surfaces; heating the soil sample at 600 deg. C induced changes on the iron oxide mineralogy with a significant decrease of the catalytic activity

  11. Iron Oxides from Volcanic Soils as Potential Catalysts in the Water Gas Shift Reaction

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    Pizarro, C.; Escudey, M.; Moya, S. A.; Fabris, J. D.

    2005-04-01

    This study was focused on changes of the iron oxide mineralogy with temperature of two Chilean soils (Andisol and Ultisol) derived from volcanic materials and their use as iron-based catalysts in the water gas shift reaction (WGSR). Ultisol materials produced about twice as much hydrogen than did those from Andisol upon WGSR, but in both cases hydrogen yielding increased as the heating temperature of the soil materials increased from 124°C to 500°C. The room temperature Mössbauer spectra showed an increase of the relative proportion of the magnetically ordered components as temperature increased. Higher heating temperature produced a negative effect on the catalytic activity, whereas the organic matter destruction led to a positive effect, due to an increasing exposition of the iron oxide surfaces; heating the soil sample at 600 °C induced changes on the iron oxide mineralogy with a significant decrease of the catalytic activity.

  12. 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...

  13. 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...

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

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    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

  15. 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 ...

  16. 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

  17. 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

  18. 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.  

  19. 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

  20. 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...

  1. 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.

  2. 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

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    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.

  3. Soil radon time series: Surveys in seismic and volcanic areas

    International Nuclear Information System (INIS)

    Soil radon surveys have been performed in a long term monitoring basis with SSNTD (LR 115 type II), in order to observe possible fluctuations due to high magnitude seismic events and volcanic eruptions. Five-year radon time series are available in stations located in an intense seismic zone located along the Pacific coast of Mexico. The series analyses have been performed as a function of the local seismicity and geological characteristics. A discussion is intended to explain the lack of biunivocal relation between single radon peaks and earthquakes for the long term monitoring data using SSNTDs. Examples of short term radon anomalies obtained with continuous probes are also discussed as a function of local earthquakes and meteorological perturbations. Additionally, complementary results from recent changes in the activity pattern of an active volcano indicate that degassing processes induced anomalous soil radon emanation correlated with the volcanic activity changes

  4. Use of 7Be fallout to document soil erosion and soil redistribution within Chilean vineyards

    International Nuclear Information System (INIS)

    Integrated Watershed Management for the Sustainability of Agricultural Lands was initiated in 2005 with the aim of developing a management model for sustainable agricultural systems through the use of nuclear and chemical techniques to assess the impacts of human practices. The project focuses mainly on pesticides management and modelling, including a test of the use of fallout radionuclides (FRNs) especially 7Be, as a short term erosion/sedimentation soil tracer

  5. Carbon Stabilization in Wet Tropical Forest Volcanic Soils

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    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

  6. Quaternary volcanic activity of Hudson and Lautaro volcanoes, Chilean Patagonia: New constraints from K-Ar ages

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    Yuji Orihashi

    2004-12-01

    Full Text Available Twenty-nine K-Ar ages for lavas and juvenile ejecta obtained from Hudson volcano in the southern end of the Southern Volcanic Zone and Lautaro volcano in the northern end of the Austral Volcanic Zone, which are separated by a 350 km-long volcanic gap near the Chile ridge subduction zone, were determined using unspiked method that has significant sensitivity for dating young rocks (Actividad volcánica cuaternaria de los volcanes Hudson y Lautaro, Patagonia chilena: nuevas edades K-Ar. Mediante el uso del método K-Ar 'unspiked', el cual tiene notable sensibilidad para datar rocas jóvenes (<0,1 Ma, se obtuvieron 29 edades radiométricas de lavas y piroclastos juveniles de los volcanes Hudson y Lautaro. Separados por un 'gap' volcánico de 350 km, cercano a la zona de subducción de la dorsal de Chile, estos volcanes se ubican en los extremos sur de los Andes del Sur y norte de los Andes Australes, respectivamente. Estos datos indican que el volcán Hudson ha tenido un tiempo de desarrollo notablemente largo desde hace 1 Ma hasta el presente. Está formado por una caldera bien conservada de aproximadamente 10 km de diámetro, la cual, se pensaba había sido formada por sólo un evento eruptivo, probablemente a los 6700 años AP. Sin embargo, nuestros resultados revelan que los flancos nororiental y suroriental del volcán se originaron durante épocas diferentes, siendo más antigua la formación de la estructura norte. Observaciones fotogeológicas indican la presencia de dos o, eventualmente, tres bordes de caldera. Estos antecedentes indican que el volcán Hudson tuvo una evolución más bien compleja consistente en la sobreimposición o anidamiento parcial de estructuras, más que la formación de una caldera simple. De acuerdo con los primeros resultados de los presentes autores, en el caso del volcán Lautaro, la actividad que comenzó hace aproximadamente 0,17 Ma continúa hasta el presente. Aunque es un volcán relativamente grande

  7. Selenium cycling in volcanic environments: the role of soils as reactive interfaces

    OpenAIRE

    Floor, Geerke Henriette

    2011-01-01

    Selenium (Se) is an element with important health implications that is emitted in significant amounts from volcanoes. Attracted by the fertility of volcanic soils, around 10% of the world population lives within 100 km of an active volcano. Nevertheless, the behaviour of Se in volcanic environments is poorly understood. Therefore, the main aim of this thesis is to investigate the role of soils in the Se cycling in volcanic environments. Prior to the geochemical studies, precise and accurate m...

  8. 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.

  9. 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

  10. 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

  11. Selective preservation of carbohydrates in volcanic ash soils

    Science.gov (United States)

    Kaal, J.; Buurman, P.; Nierop, K. G. J.; Piccolo, A.

    2009-04-01

    Volcanic soils (Andosols) are formed in volcanic ash and depending on environmental and climatic factors they develop to two main forms, either allophanic Andosols (dominated by amorphous minerals) or non-allophanic Andosols (dominated by Al/Fe organic matter complexes). Andosols contain the largest amounts of organic carbon of all mineral soil orders. In recent studies using analytical pyrolysis techniques on the soil organic matter (SOM) of allophanic soils from the Azores Islands (Portugal) there was no indication of preservation of plant-derived organic matter by allophane or Al3+, but the presence of large amounts of (microbial) polysaccharides and chitin suggested that secondary organic matter products were stabilized. In the present study we used 13C NMR to further explore the organic matter of the Andosols of the Azores, and applied a molecular mixing model (MMM; ascribing characteristic resonances to the main biocomponent classes carbohydrate, protein, lipid, lignin and char) to the quantified NMR spectra to allow for a quantitative comparison with pyrolysis-GC/MS. The dominance of O-alkyl and di-O-alkyl C in the NMR spectra and carbohydrate contribution to the predictions made by the MMM (50 ± 8%) confirms that the majority of the SOM can still be recognised as carbohydrate. The accumulation of secondary/microbial carbohydrates (and, to a lesser extent, secondary proteinaceous matter and chitins) is thus a key characteristic of these Andosols. NMR-MMM and pyrolysis-GC/MS were in rough agreement. However, NMR does not recognise chitin (N-containing carbohydrate-like material) and chitin-associated protein, nor can it be used to estimate the degree of degradation of the carbohydrates. Therefore, NMR (as applied here) has a very limited capacity for characterisation of the SOM particularly in the Andosols studied. On the other hand, large peaks from carboxylic and amidic functional groups detected by NMR were not observed by pyrolysis-GC/MS. It is therefore

  12. 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...

  13. Influences of Farming Management on Quality and Quantity of Soil Organic Matter in Volcanic Ash Soil

    Science.gov (United States)

    Yoshikawa, M.; Tanaka, H.; Matsumura, S.; Shimizu, T.; Zhang, M.

    2013-12-01

    Storage of soil organic matter (SOM) in terrestrial ecosystem plays a significant role in reducing carbon flux to the atmosphere and thus prevents the earth from global warming. In agricultural field, farming management, such as manure application and/or reduced tillage, are known to be effective methods to stimulate SOM storage. Volcanic ash soil, categorized into Andosols, is a major type of upland soil in Japan, and the soil contains relatively high concentration of SOM, meaning that volcanic ash soil can play an important role in carbon storage in Japan. To investigate the influences of farming management on quality and quantity of SOM, an empirical study was carried out in an upland soil field derived from volcanic ash. Surface soil samples were taken every three months from the field and fractionated physically and chemically. As for the physical fractionation, 53 μm sieving was performed. SOM in the samples were sorted into particulate organic matter (POM) denoting organic matter with particle size greater than 53 μm and less than 2 mm, and mineral-associated organic matter (MOM) denoting less than 53 μm. In addition, both POM and MOM were further fractionated chemically by extraction with pyrophosphate buffer solutions at three different pH levels. The fractionated organic matter as well as unfractionated SOM were analyzed and quantified for organic carbon, nitrogen content. This study induced the following results and findings. The manure and/or reduced tillage treatments can significantly increase the particulate organic carbon (POC) and all chemically fractionated POC contents. Especially, POC extracted with the buffer solution at pH4 (POCpH4) and the differences between POC and POC extracted with the buffer solution at pH10 (POC-POCpH10) have strong correlations with SOC, and manure application can effectively increase POC-POCpH10 fraction. The results indicate that these fractionated organic carbons would contribute storage of organic matter in

  14. Soil Properties Affecting the Reductive Capacity of Volcanic Ash Soils in Korea

    Science.gov (United States)

    Chon, C.; Ahn, J.; Kim, K.; Park, K.

    2008-12-01

    Volcanic ash soils or Andisols have distinct chemical and mineralogical properties. The unique chemical properties of Andisols are due to their Al-rich elemental composition, the highly reactive nature of their colloidal fractions, and their large surface area. The soils that developed from volcanic ash on Jeju Island, Korea, were classified as typical Andisols. The soils had an acidic pH, high water content, high organic matter, and clay-silty texture. The crystalline minerals in the samples were mainly ferromagnesian minerals, such as olivine and pyroxene, and iron oxides, such as magnetite and hematite derived from basaltic materials. A large amount of gibbsite was found in the subsurface horizon as a secondary product of the migration of excess Al. In addition, we found that considerable amounts of poorly ordered minerals like allophane and ferrihydrite were present in the Jeju soils. The SiO2 contents were lower than those of other soil orders, while the Al2O3 and Fe2O3 contents were higher. These results reflect some of the important chemical properties of Andisols. The chromium (VI/III) redox couple was used in the reductive capacity measurement. The mean reductive capacity of the Jeju soils was 6.53 mg/L reduced Cr(VI), which is 5.1 times higher than that of non-volcanic ash soils from inland Korea. The reductive capacity of the inland soils was correlated with the total carbon content. Such a high capacity for the reduction of soluble Cr(VI) must also be due to the relatively high carbon contents of the Jeju soils. Nevertheless, despite having 20 times higher total carbon contents, there was no correlation between the reductive capacity of the Jeju soils and the carbon content. These results imply that the reductive capacity of Jeju soils is not only controlled by the carbon content, but is also affected by other soil properties. Correlations of the reductive capacity with major elements showed that Al and Fe were closely connected to the reductive

  15. 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

  16. Phosphorus dynamics of representative volcanic ash soils through the use of conventional and isotopic techniques

    International Nuclear Information System (INIS)

    In Chile, the total extension covered by volcanic ash soils including recent and old volcanic deposits is around 5,244,400 ha. This study was carried out in 'La Araucania and Los Lagos' regions (IX and X Regions of Chile respectively), which cover approximately 2,350,000 ha. The main chemical characteristics of these soils are: very low available P (Olsen); a high P retention capacity and a high quantity of aluminum (Al) associated to a high amount of short-range order minerals. The main objective of this study was the characterization of the P dynamics of representative volcanic soils through the use of conventional and isotopic techniques. In the X Region (Los Lagos) of Chile samples from the arable layer (0-20 cm) of eleven soils (Ultisols and Andisols) were collected. Four entire soil profiles were sampled in the IX Region (Araucania). The characterization of soils was made utuilising conventional and isotopic analyses. The P retention was over 85% in all soils, except for the Metrenco soil series (Paleudult). Nevertheless, the P retention of this soil, from 72% to 79% can be also considered high for a non-volcanic ash soil. In the same way, the Al+1/2 Fe (ox) in all profiles showed high values for non-volcanic ash soils. These results indicate the great difficulty in increasing the available P in these soils, even when high rates of phosphate fertilizers are applied. The principal P-limiting factor in both regions was the P intensity factor. (author)

  17. Phosphorus dynamics of representative volcanic ash soils through the use of conventional and isotopic techniques

    International Nuclear Information System (INIS)

    In Chile, the total extension covered by volcanic ash soils including recent and old volcanic deposits is around 5,244,400 ha. This study was carried out in 'La Araucania and Los Lagos' regions (IX and X Regions of Chile respectively), which cover approximately 2,350,000 ha. The main chemical characteristics of these soils are: very low available P (Olsen); a high P retention capacity and a high quantity of aluminum (Al) associated to a high amount of short-range order minerals. The main objective of this study was the characterization of the P dynamics of representative volcanic soils through the use of conventional and isotopic techniques. In the X Region (Los Lagos) of Chile samples from the arable layer (0-20 cm) of eleven soils (Ultisols and Andisols) were collected. Four entire soil profiles were sampled in the IX Region (Araucania). The characterization of soils was made utilising conventional and isotopic analyses. The P retention was over 85% in all soils, except for the Metrenco soil series (Paleudult). Nevertheless, the P retention of this soil, from 72% to 79% can be also considered high for a non-volcanic ash soil. In the same way, the Al+1/2 Fe (ox) in all profiles showed high values for non-volcanic ash soils. These results indicate the great difficulty in increasing the available P in these soils, even when high rates of phosphate fertilizers are applied. The principal P-limiting factor in both regions was the P intensity factor. (author)

  18. Assessing microbial activities in metal contaminated agricultural volcanic soils - An integrative approach.

    Science.gov (United States)

    Parelho, C; Rodrigues, A S; Barreto, M C; Ferreira, N G C; Garcia, P

    2016-07-01

    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. Trace metal contaminated soils have significant effects on soil microbial activities and hence on soil quality. The aim of this study is to determine the soil microbial responses to metal contamination in volcanic soils under different agricultural land use practices (conventional, traditional and organic), based on a three-tier approach: Tier 1 - assess soil microbial activities, Tier 2 - link the microbial activity to soil trace metal contamination and, Tier 3 - integrate the microbial activity in an effect-based soil index (Integrative Biological Response) to score soil health status in metal contaminated agricultural soils. Our results showed that microbial biomass C levels and soil enzymes activities were decreased in all agricultural soils. Dehydrogenase and β-glucosidase activities, soil basal respiration and microbial biomass C were the most sensitive responses to trace metal soil contamination. The Integrative Biological Response value indicated that soil health was ranked as: organic>traditional>conventional, highlighting the importance of integrative biomarker-based strategies for the development of the trace metal "footprint" in Andosols. PMID:27057992

  19. 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...

  20. Chemical composition of soils in the areas of volcanic ashfalls around active volcanoes in Kamchatka

    Science.gov (United States)

    Zakharikhina, L. V.; Litvinenko, Yu. S.

    2016-03-01

    The geochemical features of volcanic soils (Andosols) in the northern soil province of Kamchatka are identified. The background regional concentrations ( Cb r ) of most of chemical elements in the studied soils are lower than their average concentrations in soils of the world and in the European volcanic soils. Only Na, Ca, and Mg are present in elevated concentrations in all the studied soils in the north of Kamchatka. Regional background concentrations of elements are exceeded by 1.6 times in the area of active ashfalls of the Tolbachik volcano and by 1.3 times in the area of active ashfalls of the Shiveluch volcano. The concentrations of mobile forms of elements in these areas exceed their regional background concentrations by 2.1 and 2.6 times, respectively.

  1. 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...

  2. Soil radon concentration and volcanic activity of Mt. Etna before and after the 2002 eruption

    International Nuclear Information System (INIS)

    Soil radon investigation, using a continuous measurement device, has been performed on Mt. Etna in order to observe possible anomalies due to seismic and/or volcanic activity. In October 2002 an eruptive event occurred. Measurements, performed on the NE flank, have shown a possible correlation between eruptive activity of the volcano and soil radon concentration anomaly. The study of the seismic activity recorded in the same flank has, also, allowed to characterize the volcano dynamics and to correlate it with the variations of radon. The obtained results seem to indicate a possible dependence on volcanic activity of the radon concentration

  3. 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.

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

    International Nuclear Information System (INIS)

    Soil radon behaviour related to the initial phase of volcanic eruptions is analysed from reported values related to the explosivity 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. 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.

  6. Silicon isotopes in allophane as a proxy for mineral formation in volcanic soils

    International Nuclear Information System (INIS)

    Highlights: → The fate of dissolved Si in volcanic soils strongly depends on Al availability. → Lighter δ30Si ratios in allophane relative to the basalt reflect weathering processes. → Heavier δ30Si ratios in allophane indicate Si precipitation as Al is humus-complexed. → Allophane δ30Si ratios could be useful in paleo-environmental reconstruction. - Abstract: Weathering of basaltic ash in volcanic areas produces andosols, rich in allophane and ferrihydrite. Since the rate of mineral formation is very useful in climate and geochemical modelling, this study investigates Si isotope compositions of allophane as a proxy for mineral formation. Allophane formed in contrasting conditions in five Icelandic soil profiles displays silicon isotope signatures lighter than the basalt in less weathered soils (-0.64 ± 0.15 per mille), and heavier in more weathered organic-rich soils (+0.23 ± 0.10 per mille). The fate of the dissolved Si in those volcanic soils strongly depends on Al availability. In organic-rich soils, most of Al is humus-complexed, and the results support that Si precipitates as opaline silica by super-saturation, leaving an isotopically heavier dissolved Si pool to form allophane with uncomplexed Al. This study highlights that Si isotopes can be useful to record successive soil processes involved in mineral formation, which is potentially useful in environmental paleo-reconstruction.

  7. Silicon isotopes in allophane as a proxy for mineral formation in volcanic soils

    Energy Technology Data Exchange (ETDEWEB)

    Opfergelt, S., E-mail: sophie.opfergelt@uclouvain.be [Department of Earth Sciences, University of Oxford, South Parks Road, Oxford OX1 3AN (United Kingdom)] [Earth and Life Institute, Universite catholique de Louvain, Croix du Sud 2/10, 1348 Louvain-la-Neuve (Belgium); Georg, R.B. [Trent University, Worsfold Water Quality Centre, 1600 West Bank Dr., Peterborough, Ontario (Canada); Burton, K.W. [Department of Earth Sciences, University of Oxford, South Parks Road, Oxford OX1 3AN (United Kingdom); Guicharnaud, R. [Agricultural University of Iceland, Keldnaholt 112, Reykjavik (Iceland); Siebert, C. [Department of Earth Sciences, University of Oxford, South Parks Road, Oxford OX1 3AN (United Kingdom); Gislason, S.R. [Institute of Earth Sciences, University of Iceland, Sturlugata 7, 101 Reykjavik (Iceland); Halliday, A.N. [Department of Earth Sciences, University of Oxford, South Parks Road, Oxford OX1 3AN (United Kingdom)

    2011-06-15

    Highlights: > The fate of dissolved Si in volcanic soils strongly depends on Al availability. > Lighter {delta}{sup 30}Si ratios in allophane relative to the basalt reflect weathering processes. > Heavier {delta}{sup 30}Si ratios in allophane indicate Si precipitation as Al is humus-complexed. > Allophane {delta}{sup 30}Si ratios could be useful in paleo-environmental reconstruction. - Abstract: Weathering of basaltic ash in volcanic areas produces andosols, rich in allophane and ferrihydrite. Since the rate of mineral formation is very useful in climate and geochemical modelling, this study investigates Si isotope compositions of allophane as a proxy for mineral formation. Allophane formed in contrasting conditions in five Icelandic soil profiles displays silicon isotope signatures lighter than the basalt in less weathered soils (-0.64 {+-} 0.15 per mille), and heavier in more weathered organic-rich soils (+0.23 {+-} 0.10 per mille). The fate of the dissolved Si in those volcanic soils strongly depends on Al availability. In organic-rich soils, most of Al is humus-complexed, and the results support that Si precipitates as opaline silica by super-saturation, leaving an isotopically heavier dissolved Si pool to form allophane with uncomplexed Al. This study highlights that Si isotopes can be useful to record successive soil processes involved in mineral formation, which is potentially useful in environmental paleo-reconstruction.

  8. 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.

  9. 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

  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. 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...

  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

    2016-04-01

    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.

  13. Adsorption of glyphosate on variable-charge, volcanic ash-derived soils.

    Science.gov (United States)

    Cáceres-Jensen, L; Gan, J; Báez, M; Fuentes, R; Escudey, M

    2009-01-01

    Glyphosate (N-phosphonometylglycine) is widely used due to its broad spectrum of activity and nonselective mode of action. In Chile it is the most used herbicide, but its adsorption behavior in the abundant and widespread variable charge soils is not well understood. In this study, three volcanic ash-derived soils were selected, including Andisols (Nueva Braunau and Diguillin) and Ultisols (Collipulli), to evaluate the adsorption kinetics, equilibrium isotherms, and the effect of pH in glyphosate adsorption. The influence of glyphosate on soil phosphorus retention was also studied. Glyphosate was rapidly and strongly adsorbed on the selected soils, and adsorption isotherms were well described by the Freundlich relationship with strong nonlinearity (n(fads) Andisol soils without the addition of glyphosate had similar mean K(ads) values for Nueva Braunau (5.68) and Diguillin (7.38). Collipulli had a mean K(ads) value of 31.58. During the successive desorption steps, glyphosate at the highest level increased K(ads) values for phosphate in the Andisol soils but had little effect in the Ultisol soil. This different behavior was probably due to the irreversible occupation of some adsorption sites by glyphosate in the Ultisol soil attributed to the dominant Kaolinite mineral. Results from this study suggest that in the two types of volcanic soils, different mechanisms are involved in glyphosate and phosphate adsorption and that long-term use of glyphosate may impose different effects on the retention and availability of phosphorus. Volcanic ash-derived soils have a particular environmental behavior in relation to the retention of organic contaminants, representing an environmental substrate that may become highly polluted over time due to intensive agronomic uses. PMID:19465720

  14. Solute Diffusivity of Repacked Volcanic Ash Soil: Effect of Changes in Pore Size Distribution due to Soil Compaction

    Science.gov (United States)

    Perera, M. S.; Resurreccion, A. C.; Kawamoto, K.; Komatsu, T.; Moldrup, P.

    2007-12-01

    Diffusion is the dominant spreading mechanism of contaminants dissolved in soil-water in the absence of soil- water flow. Solute diffusion coefficient, Ds, is a key parameter in investigating the fate and transport of contaminants from a polluted soil site. However, only a few studies on quantifying Ds as a function of soil- water content were done, especially for aggregated soils with a dual pore system such as volcanic ash soils (Andisols). In this study, we investigated the effect of bulk density on pore size distribution, and, consequently, on solute diffusivity (Ds/Do, where Do is the solute diffusion coefficient in pure water) in repacked volcanic ash soil taken at 5-10 cm depth at a pasture site in Nishi-Tokyo, Japan. Measurements of Ds were done on sieved and repacked soil at three bulk densities (0.62 g cm-3 , 0.7 g cm-3, and 0.8 g cm-3 ) and at three soil moisture conditions at pF (= log (-ψ; soil-water matric potential in cm H2O)) 1.8, 2, and 3 for each bulk density. Half-cell method was used to measure Ds where the source and sink half cells (each cell of 10-cm length and 4.9 cm in diameter) were joined together and the concentration profile was analyzed after a substantial time to determine Ds. Results showed that at a particular bulk density, Ds decreased with decreasing degree of saturation. This is expected since as the soil becomes drier, water films become disconnected resulting in a decrease in Ds. On the other hand, at a particular degree of saturation, the magnitude of Ds considerably decreases with increasing dry bulk density. As soil is compacted (and thus the increase in bulk density), the observed pore size distribution obtained from soil-water retention curve changes where the mainly inter-aggregate large pores become smaller and soil particles become closer to each other. This reduction in inter-aggregate pore size likely increases the liquid-phase tortuosity resulting in the decrease in Ds/Do at soil-water content at pF Andisols are

  15. Irreversibility of 2,4-Dichlorophenoxyacetic Acid Sorption onto a Volcanic Ash Soil

    Science.gov (United States)

    Mon, E.; Kawamoto, K.; Komatsu, T.; Moldrup, P.

    2008-12-01

    Pesticide sorption and desorption in soils are key processes governing fate and transport of pesticides in the soil environment. The irreversibility (or hysteresis) in the processes of pesticide sorption and desorption needs to be known to accurately predict behavior of pesticides in soil systems. 2,4-dichlorophenoxyacetic acid (2,4-D) is a widely used pesticide in agriculture fields. However, only few studies of 2,4-D adsorption onto Andosols (volcanic ash soils) have been published, and the knowledge of 2,4-D desorption onto Andosols is very limited. In this study, a volcanic ash soil sampled from a pasture site in Nishi-Tokyo, Japan was used as a sorbent in order to investigate the irreversibility of 2,4-D sorption. For comparison, a pure clay mineral (kaolinite) obtained from Clay Science Society of Japan (CSSJ) was also used. 2,4-D solutions with three concentrations (0.011, 0.022 and 0.045 mmol/L) were prepared in artificial rain water (ARW= 0.085mM NaCl + 0.015mM CaCl2) to simulate field conditions. To prepare the sample solutions, the solid mass/liquid volume ratio of 1:10 was used for both sorbents (volcanic ash soil and kaolinite). The experiments were conducted in triplicate using a batch method under different pH conditions to examine the effect of pH. Desorption was measured during a equilibration procedure: After removal of 7 mL of supernatant in the sorption step, 7 mL of ARW excluding 2,4-D was added to the sample solution after which, it was equilibrated and centrifuged. The procedure was performed sequentially three or four times to obtain a desorption isotherm. Sorption and desorption generally followed Freundlich isotherms. The results showed markedly effects of pH on 2,4-D sorption and desorption in both the soil and kaolinite, with the percentage of sorption increasing with decreasing pH whereas the percentage of desorption decreased. There was a larger adsorption-desorption hysteresis in the volcanic ash soil as compared to kaolinite

  16. 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...

  17. 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

  18. 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.

  19. The structural-functional organization of thermotolerant complexes of actinomycetes in desert and volcanic soils

    Science.gov (United States)

    Zenova, G. M.; Kurapova, A. I.; Lysenko, A. M.; Zvyagintsev, D. G.

    2009-05-01

    It has been found that the number of thermotolerant actinomycetes in strongly heated soils of deserts and volcanic regions is comparable to or exceeds the number of mesophilic actinomycetes. Among the latter group, streptomyces usually predominate; among thermotolerant actinomycetes, representatives of the Micromonospora, Streptosporangium, Actinomadura, Saccharopolyspora, Microtetraspora, and Microbispora genera are identified. Thermotolerant actinomycetes display the full cycle of their development in these soils. The method of fluorescent in situ hybridization has made it possible to determine that mycelial forms predominate among the metabolically active representatives of Actinobacteria; their portion increases with the rise in the temperature of soil incubation.

  20. 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

  1. 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)

  2. 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)

  3. Environmental radioactivity level and soil radon measurement of a volcanic region in Cameroon

    International Nuclear Information System (INIS)

    A part of the survey programme on the evaluation of environmental radioactivity in Cameroon has just been initiated. The radioactivity level of soils in a volcanic area in Cameroon was determined and discussed. 30 soils samples were collected from Buea and Limbe cities located in the south-western Cameroon. These two regions are known for theirs volcanic grounds due to the presence of Mount Cameroon mountain. The activity concentrations of natural radionuclides as well as that of the fission product were evaluated by gamma-ray spectrometry using a hyper purity germanium detector (HPGe). The ranges of concentrations in the surveyed soils were 11 - 17 Bq kg-1, 22 - 36 Bq kg-1 and 43 - 201 Bq kg-1 for 226Ra, 232Th and 40K, respectively. The radioisotope 137Cs was also found but in a very small amount. The outdoor absorbed dose rate 1 m above ground with the corresponding annual effective dose rate, assuming a 20% occupancy factor were estimated. The radium equivalent and the external hazard index were also evaluated and results are compared with available data from other studies and with the world average value (UNSCEAR, 1988, 2000). A solid state nuclear track detector (SSNTDs), LR-115 was used for soil radon measurements at a depth of 50 cm. The ranges of soil radon concentrations were 6.7 - 10.8 kBq m-3 and 5.5 - 8.7 kBq m-3 in Buea and Limbe, respectively. A positive correlation was found between concentrations of radium measured with γ-spectrometry and the soil radon concentrations measured with the nitrate cellulose detectors. The results of this study provide the radioactivity level in soil of a volcanic area, which has been found to be within the safety limits. The south-western Cameroon can be considered as having normal natural background radiation in normal living conditions. (author)

  4. Sorption kinetics of diuron on volcanic ash derived soils.

    Science.gov (United States)

    Cáceres-Jensen, Lizethly; Rodríguez-Becerra, Jorge; Parra-Rivero, Joselyn; Escudey, Mauricio; Barrientos, Lorena; Castro-Castillo, Vicente

    2013-10-15

    Diuron sorption kinetic was studied in Andisols, Inceptisol and Ultisols soils in view of their distinctive physical and chemical properties: acidic pH and variable surface charge. Two types of kinetic models were used to fit the experimental dates: those that allow to establish principal kinetic parameters and modeling of sorption process (pseudo-first-order, pseudo-second-order), and some ones frequently used to describe solute transport mechanisms of organic compounds on different sorbents intended for remediation purposes (Elovich equation, intraparticle diffusion, Boyd, and two-site nonequilibrium models). The best fit was obtained with the pseudo-second-order model. The rate constant and the initial rate constant values obtained through this model demonstrated the behavior of Diuron in each soil, in Andisols were observed the highest values for both parameters. The application of the models to describe solute transport mechanisms allowed establishing that in all soils the mass transfer controls the sorption kinetic across the boundary layer and intraparticle diffusion into macropores and micropores. The slowest sorption rate was observed on Ultisols, behavior which must be taken into account when the leaching potential of Diuron is considered. PMID:23995557

  5. 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...

  6. Two pools of old carbon in a volcanic-ash soil revealed by sequential density fractionation

    Science.gov (United States)

    Wagai, R.; Shirato, Y.; Uchida, M.; Hiradate, S.

    2010-12-01

    Volcanic-ash soils are often darker and hold significantly greater amounts of organic matter (OM) than non-volcanic soils presumably because inorganic constituents unique to such soil (e.g., poorly-crystalline minerals and dissolved aluminum) have high capacity to stabilize OM. It has been shown that carbon (C) in Japanese volcanic-ash soils can be quite old (>1000 yr) even at surface horizons. Yet little information is available on how the old C is stabilized in soil matrix. Fractionation of soil according to particle density is an effective approach to distinguish the OM of different degrees of mineral associations and to elucidate SOM stabilization processes. Here we examined a surface (Ap) horizon of an allophanic Andisol in central Japan by isolating six density fractions (from F1: 2.5 g/cc). Almost half of total C was distributed to F4 (2.0-2.25 g/cc), 26% of total C to F3 (1.8-2.0 g/cc), 10-12% to F2 (1.6-1.8 g/cc) and F5 (2.25-2.5 g/cc), and 3-4% to F1 and F6, respectively. The concentration of allophane was also highest in F4 then F3, implying that allophane-OM association is the main form of OM present in this soil. In accord with the reports on other soil types, C-14 age generally increased with particle density from F1 (modern) to F5 (1300 yr libby age) and slightly declined to F6 (1000 yr). The clear exception to this trend was the old C age (1300 yr) of 1.6-1.8 g/cc fraction. Following results suggested the presence of char in this fraction: (i) C:N ratio was the highest (22), (ii) aromatic-C:O-alkyl-C ratio nearly doubled from F1 to F2, and (iii) large numbers of small, dark fragments were microscopically observed along with plant detritus fragments. In contrast to F2, equally-old C in F5 (2.25-2.5 g/cc) appear to be strongly altered by microbial process and bound to mineral particles. F5 had lower C:N ratio of 9.7 and was more enriched in N-15 (+5 per mill) and C-13 (+2 per mill) compared to F2. The presence of contrasting forms of old C suggest

  7. 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

  8. 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

  9. 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

  10. 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

  11. 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.

  12. Melanic and Fulvic Andisols in Volcanic Soils derived from some Volcanoes in West Java

    Directory of Open Access Journals (Sweden)

    Rina Devnita

    2014-07-01

    Full Text Available DOI: 10.17014/ijog.v7i4.149Melanic and fulvic Andisols are the great groups in the classification of volcanic soils Andisols, which describe the soils with high organic carbon content in the epipedon. The organic C must be more than 6% in the upper 30 cm with the value and chroma are 2 or less for melanic and more than 2 for fulvic. Melanic epipedon also has to have the melanic index that is 1.70 or less. The objective of this study is to investigate the melanic and fulvic Andisols in volcanic soils that developed under pine forest vegetation (Pinus merkusii from different parent materials and ages of Mount Tangkuban Parahu (andesitic, Holocene and Mount Tilu (basaltic, Pleistocene. The method used was a descriptive comparative survey of three profiles in Mount Tangkuban Parahu and three profiles in Mount Tilu. Analyses were done for each horizon in the profiles comprising the investigation of andic soil properties through the analyses of organic C, bulk density, Al + ½ Fe (ammonium oxalate, and P-retention. The investigations were continued by further calculation of organic C content and by investigation of soil colour with Munsell Soil Colour Chart. The results showed that the two profiles in Mount Tangkuban Parahu and two profiles in Mount Tilu are fulvic Andisol. No melanic Andisols were found in both locations. Pine forest vegetation encourages the formation of fulvic Andisols were derived from andesitic-Holocene parent materials or basaltic-Pleistocene parent materials.

  13. 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

  14. 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

  15. Ammonia emissions from urea application to permanent pasture on a volcanic soil

    Science.gov (United States)

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

    2012-12-01

    Agriculture is the largest source of ammonia (NH3) emission to the atmosphere, deriving mainly from livestock urine and manures, but fertilizer applications to pastures and crops also represent an important source. In Chile, where agriculture and cattle production are important activities (accounting for 4.5% of GDP along with the forestry sector), there are very few published data regarding NH3 emissions from pasture and crop fertilization. This study aimed to provide the first empirical field data for Chile on N losses due to NH3 volatilization following urea application to permanent pasture on a volcanic soil and to assess the influence of environmental conditions on emissions. Four field experiments were carried out on a volcanic acid soil using the micrometeorological integrated horizontal flux (IHF) mass balance method. Measurements were made in winter 2005 and 2007, and spring 2007 and 2008 following urea N fertilization to a permanent pasture at a rate equivalent to 100 kg N ha-1. Cumulative NH3 emissions over the measurement period were 1.4 and 7.7 kg N ha-1 for winter applications, and 12.2 and 26.7 kg N ha-1 for spring dressings. These N losses due to NH3 volatilization are within the range of emissions reported elsewhere. Consideration of urea application timing in Chile, with regards to weather and soil conditions, could have important consequences on minimising potential N losses via volatilization with associated financial benefits to farmers.

  16. Influence of Organic Matter on the Iron Oxide Mineralogy of Volcanic Soils

    Science.gov (United States)

    Pizarro, C.; Escudey, M.; Fabris, J. D.

    2003-06-01

    Samples of soils developing on volcanic materials that represent about 70% of the agriculture land area in Chile were studied by chemical methods, powder X-ray diffractometry (XRD) and Mössbauer spectroscopy. The soil samples were collected from native areas of Ultisols, Andisols, and Andisols presenting seasonal cycles of poor drainage, at depths between 0-15 cm and 15-30 cm from the top of the profile. The degree of crystallinity of iron oxides was evaluated from the ratio of amounts of Fe extracted with oxalate-oxalic acid (FeOX) and with bicarbonate-citrate-dithionite mixtures (FeDBC), FeOX/FeDBC. Results show that the specific saturation magnetization of soils and crystallinity of iron-rich minerals increase with decreasing organic matter contents of soils. From XRD and Mössbauer data, ferrihydrite (ideal formula, Fe5HO8ṡ4H2O) could be the precursor either of the soil magnetite (Fe3O4) or hematite (αFe2O3). Older soils were found to be in an intermediate stage regarding the transformation of magnetite to maghemite (γFe2O3).

  17. Influence of Organic Matter on the Iron Oxide Mineralogy of Volcanic Soils

    International Nuclear Information System (INIS)

    Samples of soils developing on volcanic materials that represent about 70% of the agriculture land area in Chile were studied by chemical methods, powder X-ray diffractometry (XRD) and Moessbauer spectroscopy. The soil samples were collected from native areas of Ultisols, Andisols, and Andisols presenting seasonal cycles of poor drainage, at depths between 0-15 cm and 15-30 cm from the top of the profile. The degree of crystallinity of iron oxides was evaluated from the ratio of amounts of Fe extracted with oxalate-oxalic acid (FeOX) and with bicarbonate-citrate-dithionite mixtures (FeDBC), FeOX/FeDBC. Results show that the specific saturation magnetization of soils and crystallinity of iron-rich minerals increase with decreasing organic matter contents of soils. From XRD and Moessbauer data, ferrihydrite (ideal formula, Fe5HO8.4H2O) could be the precursor either of the soil magnetite (Fe3O4) or hematite (αFe2O3). Older soils were found to be in an intermediate stage regarding the transformation of magnetite to maghemite (γFe2O3).

  18. Influence of Organic Matter on the Iron Oxide Mineralogy of Volcanic Soils

    Energy Technology Data Exchange (ETDEWEB)

    Pizarro, C.; Escudey, M. [Universidad de Santiago de Chile, Facultad de Quimica y Biologia (Chile); Fabris, J. D. [ICEx-UFMG, Pampulha, Departamento de Quimica (Brazil)

    2003-06-15

    Samples of soils developing on volcanic materials that represent about 70% of the agriculture land area in Chile were studied by chemical methods, powder X-ray diffractometry (XRD) and Moessbauer spectroscopy. The soil samples were collected from native areas of Ultisols, Andisols, and Andisols presenting seasonal cycles of poor drainage, at depths between 0-15 cm and 15-30 cm from the top of the profile. The degree of crystallinity of iron oxides was evaluated from the ratio of amounts of Fe extracted with oxalate-oxalic acid (Fe{sub OX}) and with bicarbonate-citrate-dithionite mixtures (Fe{sub DBC}), Fe{sub OX}/Fe{sub DBC}. Results show that the specific saturation magnetization of soils and crystallinity of iron-rich minerals increase with decreasing organic matter contents of soils. From XRD and Moessbauer data, ferrihydrite (ideal formula, Fe{sub 5}HO{sub 8}.4H{sub 2}O) could be the precursor either of the soil magnetite (Fe{sub 3}O{sub 4}) or hematite ({alpha}Fe{sub 2}O{sub 3}). Older soils were found to be in an intermediate stage regarding the transformation of magnetite to maghemite ({gamma}Fe{sub 2}O{sub 3}).

  19. 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

  20. [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

  1. 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

  2. Effect of management of a volcanic ash soil on structural properties

    Directory of Open Access Journals (Sweden)

    Smith R.

    2000-12-01

    Full Text Available In Hapludand, Southern Chile with different types of land use and differentiated time periods after clear-cutting of the native forest by fire, the following parameters: pore size distribution, bearing capacity, internal cohesion, penetration resistance and spatial stress distri- bution due to loading were determined. The most pro- nounced settlement occurs immediately after forest clear- ing. During consecutive periods of land use, the settlement rate became smaller. Additionally, the major settlements occur on the sites with a long time of agricultural landuse while mere strong grassing had a smaller effect. As ex- pected, changes in the pore size distribution could be de- tected. Coarse pores decrease and the amount of medium pores increases. These changes depended on the pedolo- gical environment and soil use. Due to the rearrangement of the parent volcanic ash material and the corresponding aggregates during soil settlement as a consequence of stress induced changes in the shape of the particles and the more spherical shape, soil penetration resistance increased with settlement as well as the amount of roots above the plow pan layer. The latter is also an index of the impermeability as a consequence of the assumed increase in the contact points due to loading and “reformation“of these particles. Accor- ding to utilization-type, soil strength differs. The same soil can either react very stable or is extremely weak even if only a small stress, e.g., by an agricultural machinery, has been applied. Recently, cultivated agricultural sites have low pre- compression strength and internal cohesion values. Due to the rearrangement of particles and shape as a consequence of soil deformation during land use the strength increase even if the pore size distribution doesn’t change con- siderably. More detailed informations are given in the text.

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

    Science.gov (United States)

    Ersoy, Hakan; Karsli, Melek Betül; Çellek, Seda; Kul, Bilgehan; Baykan, İdris; Parsons, Robert L.

    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.

  4. Sulfate adsorption and surface precipitation on a volcanic ash soil (allophanic andisol).

    Science.gov (United States)

    Ishiguro, Munehide; Makino, Tomoyuki; Hattori, Yasunobu

    2006-08-15

    Sulfate strongly adsorbs on metal oxides and soils with variable charges. However, its surface precipitation has not been clearly evaluated and its adsorption mechanism has been in dispute. In the present study, an allophanic andisol, a typical volcanic ash soil having both negative and positive variable charges, was used to identify the adsorption mechanism of sulfate. Sulfate adsorption isotherms were obtained by a batch method at pH values of 4, 5, 6, and 7 in a wide range of concentrations in an Na-H-SO(4)-OH system. Theoretical isotherms were applied to the measured values for the evaluation. The surface precipitation was detected by the measured adsorption isotherms, and the BET isotherm confirmed the presence of multilayer adsorption. Stronger and weaker adsorption sites were suggested by using the Langmuir isotherm for the monolayer adsorption. The adsorption energies obtained from the Langmuir equation and recent spectroscopic analysis suggested that the stronger adsorption corresponded to an inner-sphere surface complex and that the weaker adsorption corresponded to outer-sphere surface complexation. The BET and Langmuir equations showed three types of adsorption mechanisms for the sulfate adsorption on the soil. PMID:16750540

  5. Laboratory scale of rainfall's pattern and threshold in volcanic soil slope failure

    Science.gov (United States)

    Kartiko, R. D.; Sadisun, I. A.; Tohari, A.; Sumintadiredja, P.

    2016-05-01

    Relationship between rainfall pattern, threshold and landslide process have widely developed. However, real-time observation in real landslide event is time consuming and has high degree of uncertainty. Therefore more analysis is usually developed in regional data scale with correlation between regional rainfall dataset and landslide inventory mapping. In this study, another approach is developed with a physical laboratory scale model. This research developed correlation between simulated rainfall pattern with mechanism and process of landslide. Rainfall with specific intensity and duration are given in residual volcanic soil in laboratory scale. Rainfall threshold observed between laboratory and regional model is highly correlated. There also occurred clear relationships between intensity, duration, antecedent rainfall, with rainfall's initiation and morphology.

  6. 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)

  7. 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.

  8. 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

  9. Ammonia oxidizers are pioneer microorganisms in the colonization of new acidic volcanic soils from South of Chile.

    Science.gov (United States)

    Hernández, Marcela; Dumont, Marc G; Calabi, Marcela; Basualto, Daniel; Conrad, Ralf

    2014-02-01

    Ammonia oxidation, performed by specialized microorganisms belonging to the Bacteria and Archaea, is the first and most limiting step of soil nitrification. Nitrification has not yet been examined in young volcanic soils. The aim of the present work was to evaluate the abundance and diversity of ammonia-oxidizing bacteria (AOB) and archaea (AOA) in acidic volcanic soils (andisols) of different defined ages to determine their relative contribution to nitrification and soil colonization. Soil was collected from three vegetated sites on Llaima Volcano (Chile) recolonized after lava eruptions in 1640, 1751 and 1957. Quantitative polymerase chain reaction, terminal restriction fragment length polymorphism and clone sequence analyses of the amoA gene were performed for the AOA and AOB communities. All soils showed high nitrification potentials, but they were highest in the younger soils. Archaeal amoA genes outnumbered bacterial amoA genes at all sites, and AOA abundances were found to be proportional to the nitrification potentials. Sequencing indicated the presence of AOA related to Nitrososphaera and Nitrosotalea, and AOB related primarily to Nitrosospira and sporadically to Nitrosomonas. The study showed that both AOA and AOB are early colonizers of andisols, but that AOA outnumber AOB and play an important role in nitrification. PMID:24596264

  10. 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

  11. Radon levels in groundwaters and natural radioactivity in soils of the volcanic region of La Garrotxa, Spain

    International Nuclear Information System (INIS)

    Groundwater radon level and soil radionuclide concentration have been measured in the volcanic region of La Garrotxa (Catalonia, Spain) to further research on the origin and dynamics of high radon levels over volcanic materials found in this region. Water samples from different aquifers have been collected from wells and springs and the water radon levels obtained have been lower than 30 Bq l−1. Soil samples have been collected from different geological formations (volcanic and non-volcanic), being Quaternary sedimentary deposits those that have presented the highest mean values of 40K, 226Ra and 232Th concentrations (448 ± 70 Bq kg−1, 35 ± 5 Bq kg−1 and 38 ± 5 Bq kg−1, respectively). Additionally, indoor/outdoor terrestrial radiation absorbed dose rate in air have been measured to better characterize the region from the radiological point of view. Terrestrial radiation absorbed dose rates measurement points have been chosen on the basis of geological and demographical considerations and the results obtained, from 27 to 91 nGy h−1, show a clear relation with geological formation materials. The highest terrestrial gamma absorbed dose rate is observed over Quaternary sedimentary deposits as well. All these results help to better understand previous surveys related with indoor and outdoor radon levels and to reinforce the hypotheses of a radon transport through the fissure network. -- Highlights: • Research on the origin and dynamics of radon levels in a volcanic region. • Deep wells and springs close to important faults present higher water radon levels. • Quaternary sediments present the highest mean values of radionuclide concentration. • Results reinforce the hypotheses of a radon transport through the fissure network

  12. 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.

  13. Distinct bacterial community structure of 3 tropical volcanic soils from banana plantations contaminated with chlordecone in Guadeloupe (French West Indies).

    Science.gov (United States)

    Mercier, Anne; Dictor, Marie-Christine; Harris-Hellal, Jennifer; Breeze, Dominique; Mouvet, Christophe

    2013-08-01

    In the French West Indies (FWI), the soil, andosols, ferralsols and nitisols, is highly polluted by chlordecone, although this organochlorine insecticide extensively applied to banana crops has been banned for 20years. This contamination has led to a major human health concern inducing the need for remediation of the contaminated soils. Work was conducted to help to evaluate the impact of remediation processes on the microbial communities from these soils. Microbial biomass was estimated after direct DNA extraction from three chlordecone-contaminated soils (an andosol, a ferralsol and a nitisol) and the bacterial community analyzed using t-RFLP. The FWI volcanic andosol was particularly recalcitrant to usual direct DNA extraction protocols hampering analysis of soil microbial communities until now, in contrast with the 2 other soils. For the first time, DNA was directly extracted from a FWI andosol based on yeast RNA addition at the lysis step. Differences in microbial biomass were thus observed between the 3 FWI soils. Moreover, the bacterial community structure was significantly distinct from each other's and related to soil physico-chemical characteristics. Interestingly, differences in bacterial diversity could not be exclusively attributed to the level of chlordecone contamination. PMID:23706897

  14. 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.

  15. 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

  16. Radiocarbon-based residence time estimates of soil organic carbon in a temperate forest: Case study for the density fractionation for Japanese volcanic ash soil

    International Nuclear Information System (INIS)

    The world's soils store significantly more carbon than that is present in the atmosphere. To understand the distribution and dynamics of the soil organic carbon (SOC) reservoir and make a prediction about the response of the soil carbon pool to climate change, it is necessary to quantitatively constrain rate of soil carbon cycling. Following previous studies , we investigated the method for physically preparation of Japanese volcanic ash soil for the mean residence time (MRT) estimates in a cool-temperate deciduous forest in Japan, at one of Asia Flux monitoring sites. Sequentially isolated density fractions clearly differed in C contents and C/N ratios in soil surface (3-8 cm) and deep soil layer (38-43 cm). In soil surface layer, the light fractions (1.6-1.8, 1.6-1.8, 1.8-2.1 g cm-3) accounted for nearly 90% of SOC and their MRT ranged from 6 to 150 year. In deep layer, the 2.1-2.4 g cm-3 fraction accounted for more than 60% of SOC and its MRT was 3100 year. The lighter fractions (1.6-1.8, 1.8-2.1) comprised small portion of total SOC and were significantly slowly MRT (2038-2335 year), although it seems to consist of labile carbon.

  17. 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.

  18. 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.

  19. 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.

  20. 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 ...

  1. 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

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

    OpenAIRE

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

    2015-01-01

    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...

  3. 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

  4. 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.

  5. 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.

  6. Evaluation of Drainage from Passive Suction and Nonsuction Flux Meters in a Volcanic Clay Soil under Tropical Conditions

    Energy Technology Data Exchange (ETDEWEB)

    van der Velde, M; Green, S R.; Gee, Glendon W.; Vanclooster, M; Clothier, B E.

    2005-11-30

    Root zone drainage measurements are needed to improve fertilizer management in areas where agriculture may be impacting groundwater supplies. We present results of field tests where drainage was measured with two types of suction (resolution of 0.16 and 1.6 mm -1) and a nonsuction (resolution of 0.22 mm tip-1) water flux meter (WFM). The soil was a microstructured weathered volcanic ash located on a coral atoll subject to intense rainfall and located in the Kingdom of Tonga. Our objectives were to evaluate water flux measurements by comparing them with (i) simple water balance estimates of cumulative fluxes deduced from soil moisture content changes, and (iii) simulated fluxes using HYDRUS-1D. Soil hydraulic properties were obtained at five soil depths. During the 60-d evaluation period rainfall totaled 340 mm. The WFMs were installed in duplicate using disturbed soil. The consistency of the shape of the drainage curves measured with the WFMs, those derived from soil moisture changes, and those obtained with modeling led us to conclude that soil disturbance during WFM installation did not severely influence measurements. This was attributed to the strong microaggregation and disturbance introduced by plowing. Water balance and HYDRUS model estimates of drainage corresponded well with the measurement by nonsuction WFMs. Suction WFMs overestimated drainage, possibly due to flow convergence created by wick and divergence barrier lengths being not properly sized for the observed flow conditions. After the evaluation period some of the WFMs failed to respond. Nevertheless, flux meters are seen as promising tools to provide remote and continuous measurement of root zone drainage.

  7. Metsulfuron-methyl sorption/desorption behavior on volcanic ash-derived soils. effect of phosphate and pH.

    Science.gov (United States)

    Cáceres, Lizethly; Fuentes, Roxana; Escudey, Mauricio; Fuentes, Edwar; Báez, María E

    2010-06-01

    Metsulfuron-methyl sorption/desorption behavior was studied through batch sorption experiments in three typical volcanic ash-derived soils belonging to Andisol and Ultisol orders. Their distinctive physical and chemical properties are acidic pH and variable surface charge. Organic matter content and mineral composition affected in different ways sorption of metsulfuron-methyl (K(OC) ranging from 113 to 646 mL g(-1)): organic matter and iron and aluminum oxides mainly through hydrophilic rather than hydrophobic interactions in Andisols, and Kaolinite group minerals, as major constituents of Ultisols, and iron and aluminum oxides only through hydrophilic interactions. The Freundlich model described metsulfuron-methyl behavior in all cases (R(2) > 0.992). K(f) values (3.1-14.4 microg(1-1/n) mL(1/n) g(-1)) were higher than those reported for different class of soils including some with variable charge. Hysteresis was more significant in Ultisols. A strong influence of pH and phosphate was established for both kinds of soil, intensive soil fertilization and liming being the most probable scenario for leaching of metsulfuron-methyl, particularly in Ultisols. PMID:20455566

  8. Dynamic carbon content as an indicator of desertification processes in soils developed from volcanic parental material in the Region of Murcia

    International Nuclear Information System (INIS)

    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.

  9. 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.

  10. 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

  11. 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

  12. 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.

  13. Volcanic soil formation in Calabria (southern Italy): The Cecita Lake geosol in the late Quaternary geomorphological evolution of the Sila uplands

    Science.gov (United States)

    Scarciglia, Fabio; De Rosa, Rosanna; Vecchio, Giuseppe; Apollaro, Carmine; Robustelli, Gaetano; Terrasi, Filippo

    2008-10-01

    This paper focuses on the main morphological, physical, chemical and mineralogical features of an andic-like soil, widely outcropping in the Sila upland plateau of Calabria (southern Italy), and its potential role in tephrostratigraphy. A multidisciplinary and multiscale approach allowed identification of this soil as a "masked" distal archive of volcanic products, developed on granite rocks and sediments with a coeval pyroclastic input during pedogenesis. The study demonstrates that the contribution of volcanic parent materials can be successfully hypothesized and assessed even in the absence, limited extent or poor preservation of primary eruptive products. The soil has an Andisol-like appearance, despite laboratory data that do not match the entire suite of diagnostic criteria for the Andisol taxonomic order. Geomorphological, stratigraphic and pedologic results, coupled with tephrostratigraphic and radiometric data, concur to suggest a Late Pleistocene(?) to Holocene age of the Andisol-like soil. In particular, the rhyolitic chemical composition of small-sized glass fragments (identified by SEM-EDS analyses) indicates soil genesis contributed by volcanic ash, probably sourced from Aeolian Arc explosive activity spanning the last 30 ka. Accordingly, the evidence of limited relict clay illuviation and the specific type of pedogenesis allowing the development of andic properties (in turn related to the neoformation of clay minerals from the weathering of volcanic glass) are consistent with a climatic shift from a seasonally-contrasted to a constantly humid pedoenvironment. This change can be ascribed to the Lateglacial(?) or Early-Middle Holocene to Late Holocene transition. Calibrated AMS 14C dates performed on charcoal fragments sampled from three representative soil profiles, provide Late Holocene ages (3136 ± 19, 343 ± 16 and 92 ± 24 yr BP), in accord with archaeological finds. On the basis of the consistent stratigraphic position, lateral continuity and

  14. Effects of Inter- and Intra-aggregate Pore Space on the Soil-Gas Diffusivity Behavior in Unsaturated, Undisturbed Volcanic Ash Soils

    Science.gov (United States)

    Resurreccion, A. C.; Kawamoto, K.; Komatsu, T.; Moldrup, P.

    2006-12-01

    Volcanic ash soils (Andisols) have a unique dual porosity structure that results in good drainage and high soil- water retention. Despite of the complicated and highly developed soil structure, recent studies have reported a simple, highly linear relation between the soil-gas diffusion coefficient, Dp, and the soil-air content, ɛ, for several Japanese Andisols. In this study, we explain the linear Dp(ɛ) behavior from the effects of the inter- and intra-aggregate pore-size distributions. We couple the bimodal van Genuchten soil-water retention model with a general Dp(ɛ) model, ɛ^{X}, allowing the tortuosity- connectivity factor X to vary with pF (= log(-ψ; the soil-water matric potential in cm H2O)). Measured data suggest that the tortuosity-connectivity parameter X is at the minimum at pF 3 (where X ~ 2, following Buckingham, 1904), equal to the water retention point where a separation of inter- and intra-aggregate effects on Dp is observed. At pF 3, X increased to a high value at very dry conditions due to remote air-filled space inside the intra-aggregate pores. By combining the complex dual porosity soil-water retention model with the power- law gas diffusivity model using a parabolic X(pF) function, the surprisingly simple linear behavior of Dp with ɛ was captured while the variation of Dp with pF followed a dual s-shaped curve similar to the water retention curve. A simple linear model to predict Dp(ɛ) is suggested, with slope C and threshold soil-air content, ɛth, calculated from the power-law model ɛ^{X} at pF 2 (near field capacity) and at pF 4.1 (near wilting point) using the same X value (= 2.3) at both pF in agreement with measured data. This linear Dp(ɛ) model performed better, especially at dry conditions, compared to the traditionally-used predictive models when tested against several independent Andisol datasets from literature.

  15. 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 about......): native birch (Betula pubescens) and introduced Siberian larch (Larix sibirica). A treeless heathland was included to present soil conditions prior to forest establishment. The sites are part of the largest forest area in Iceland, located in the east of the country. Results revealed an effect of stand age...

  16. Elevation and vegetation influences on soil properties in Chilean Nothofagus forests Influencia de la elevación y la vegetación sobre las propiedades del suelo de los bosques chilenos de Nothofagus

    Directory of Open Access Journals (Sweden)

    KELLY L.M DECKER

    2003-09-01

    Full Text Available We measured net nitrogen mineralization, net nitrification, proportional nitrification, and total inorganic nitrogen, available phosphorus, and soil organic carbon in five Andean forested stands in an attempt to resolve the relative influence of elevation and forest canopy composition on soil organic matter and nutrient dynamics in this ecosystem type. Our five forested study sites were within a contiguous Nothofagus forest that ranged from 1,280 to 1,700 m elevation in the central Chilean Andes. The five sites consisted of three single species stands, one each of the low elevation deciduous N. obliqua, the evergreen N. dombeyi, or the high elevation deciduous N. pumilio, as well as two mixed evergreen-deciduous stands. There was no statistically significant relationship of nitrogen mineralization or phosphorus with elevation. In contrast, there were statistically significant, though weak, negative relationships between elevation and net nitrification, proportional nitrification, soil pH and organic carbon. In general, soils from the N. obliqua stand had higher levels/rates of nitrification, soil organic carbon content, soil pH, and plant available phosphorus than soils form the other single species stands. In contrast, the N. dombeyi and N. pumilio stands had lower rates of nitrification and soil pH than did the N. obliqua stand. The evergreen-deciduous mixed stands tended to be intermediate in soil properties. These results demonstrate that vegetation, particularly the balance of evergreen and deciduous species, exerts stronger control over soil chemical and biochemical properties than the climate variations induced by 350 m in elevation, even where the evergreen and deciduous species are closely-related angiosperms.Medimos la mineralización neta de nitrógeno, la nitrificación, el total de nitrógeno disponible, el fósforo disponible y el carbono orgánico del suelo en cinco rodales forestales andinos con el propósito de separar la

  17. Nitrate leaching through volcanic soils in the Central Valley, Costa Rica

    International Nuclear Information System (INIS)

    A pilot experiment is being conducted to evaluate water and nitrate transport processes through Andisols planted with coffee under intensive and traditional management systems in the Central Valley, Costa Rica. The region has high precipitation rates (>2000 mm), permeable soils and rocks, and high concentrations of nitrate are available in the soil, derived mainly from intensive N fertilizer applications. It has been suggested that significant amounts of nitrate form fertilizers may be leading through the soils and contributing to aquifer contamination. Tritiated water and potassium nitrate in solution were injected as tracers at a depth of 45 cm in plots in two adjacent plantations under different management systems. The preliminary results indicate that, contrary to what has been observed in temperate soils, nitrate movement is slower than that of water. It is evident that water cannot be used as a nitrate tracer in soils of a variable charge that are potentially able to adsorb anions and even to retard nitrate leaching. Different rates of nitrate transport in the two plots and lower recovery in the shaded coffee plantation suggest that large overstory trees with well developed root systems may be competing successfully with coffee bushes for nitrate and water uptake. (author). 19 refs, 2 figs, 1 tab

  18. 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)

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

    International Nuclear Information System (INIS)

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

    International Nuclear Information System (INIS)

    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

  2. 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

  3. 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.

  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. Nature, properties and function of aluminum-humus complexes in volcanic soils

    OpenAIRE

    Takahashi, T.; Dahlgren, RA

    2016-01-01

    © 2015 Elsevier B.V. Andosols (or Andisols) possess several distinctive properties that are rarely found in other groups of soils. These properties are largely due to the dominance of short-range-ordered minerals (allophane, imogolite and ferrihydrite) and/or metal-humus complexes (Al/Fe-humus complexes) in their colloidal fraction. While several papers have extensively reviewed the nature and properties of short-range-ordered minerals, there is no comprehensive review of the genesis, charact...

  6. FIJACION DE AMONIO EN SEIS SUELOS DE LA VIII REGION DE CHILE Ammonium fixation in six Chilean soils from the VIII Region of Chile

    Directory of Open Access Journals (Sweden)

    Luis Longeri S.

    2001-04-01

    Full Text Available El objetivo de este estudio fue determinar el contenido de NH4+ nativo fijado y las capacidades de fijación inducida y total de 36 muestras superficiales (0-25 cm de suelos pertenecientes a 6 series de la VIII Región: Diguillín (Andisol, Santa Bárbara (Andisol, Collipulli (Alfisol, San Carlos (Alfisol, Cauquenes (Alfisol, Quella (Vertisol. El NH4+ nativo fijado fluctuó entre 0 y 41 mg kg-1 N, con valores promedios de 1,1 a 2,5 en las series alofánicas (Andisoles y de 5,9 a 15,9 en las series no alofánicas. La capacidad de fijación inducida varió entre 0,1 y 73 mg N kg-1, con valores promedio de 1,6 a 2,3 en las series alofánicas y de 17,5 a 37,6 en las series no alofánicas, mientras que la capacidad total de fijación varió entre 0,3 y 81 mg N kg-1, con valores promedio de 3,4 a 4,1 y de 23,4 a 47,0 en el primer y segundo grupo de series, respectivamente. La fijación de NH4+ se asoció principalmente al contenido de los cationes de intercambio que expanden la red de las arcillas. Los suelos que contienen arcillas 2:1 o feldespatos fijaron más NH4+ que los otros suelos.The purpose of this study was to determine the fixed native NH4+ and the artificial and total fixing capacities in 36 superficial (0-25 cm soil samples from six soil series of the VIII Region: Diguillín (Andisol, Santa Bárbara (Andisol, Collipulli (Ultisol, San Carlos (Alfisol, Cauquenes (Alfisol and Quella (Vertisol. The fixed native NH4+ ranged from 0 to 41.2 mg N kg-1, with 1.1 to 2.5 as mean values in the allophanic series (Andisols and 5.9 to 15.9 in the non-allophanic series. The artificial fixation capacity varied between 0.1 and 72.8 mg N kg-1 with 1.6 to 2.3 as mean values in the allophanic series, and 17.5 to 37.6 in the non-allophanic series, while the total fixing capacity varied from 0.3 to 80.9 mg N kg-1 with 3.4 to 4.1 and 23.4 to 47.0 as mean values in the first and second soil groups, respectively. Ammonium fixation mainly correlated with the

  7. 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.

  8. 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) characterized by reddish-brown color (7.5YR), strong angular blocky structure and well-expressed illuvial clay coatings, rather indicates that it developed over a longer time-span and/or warmer climate than the two yellowish-brown surface soils. Since the morphology of the paleosol clearly reflects interglacial climatic conditions and forest cover, it most likely started

  9. Increasing nitrogen-use efficiency by wheat in volcanic ash soils

    International Nuclear Information System (INIS)

    Timing of application and type of N fertilizer, irrigation and interactions with S, genotypes and rotational effects were studied and progress made in selecting conditions for increasing fertilizer-N efficiency with wheat. Results indicated that residue incorporation in the rotation, optimum irrigation (>170 mm), three split applications of N and nutritional problem correction (acidification and sulfur deficiency), promoted wheat yields and fertilizer-N efficiency. Applied-N recoveries were only about 50%. However, grain yields of 6 to 8 t ha-1 were achieved when the soil was managed appropriately. The chlorophyll meter may be useful to define wheat N requirement if used in conjunction with well fertilized reference strips within the same field. (author)

  10. 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.

  11. 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.

  12. Sorption-desorption behavior of pesticides and their degradation products in volcanic and nonvolcanic soils: interpretation of interactions through two-way principal component analysis.

    Science.gov (United States)

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

    2015-06-01

    Sorption-desorption behavior of six pesticides and some degradation products was assessed on seven agricultural volcanic and nonvolcanic soils belonging to Andisol, Ultisol, Mollisol, and Alfisol orders. The global interpretation of sorption data was performed by principal component analysis. Results showed exceptionally high sorption of glyphosate and aminomethylphosphonic acid (AMPA) (the breakdown product) on volcanic soils (K f > 1500 μg(1 - 1 / n) mL(1 / n) g(-1)) related mainly to contents of amorphous aluminum oxides (Andisols) and crystalline minerals (Ultisols). The lower sorption on nonvolcanic soils was associated to low organic matter contents and lack of significant minerals. Metsulfuron-methyl and 3,5,6-trichloro-2-pyridinol (metabolite of chlorpyrifos) were weakly to substantially sorbed on Andisols and Ultisols, but the first one was not sorbed at pH > 6.4, including nonvolcanic soils. The metabolite of diazinon, 2-isopropyl-4-methyl-6-hydroxypyrimidine, was weakly sorbed on all soils (K f = 0.4 to 3.6 μg(1 - 1 / n) mL(1 / n) g(-1)). Acidic compounds would be lixiviated in Mollisols and Alfisols, but they could leach also in Andisols and Ultisols if they reach greater depths. Atrazine and deethylatrazine sorption was related to organic carbon content; therefore, they were weakly retained on nonvolcanic soils (K f = 0.7 to 2.2 μg(1 - 1 / n) mL(1 / n) g(-1)). Chlorpyrifos was highly sorbed on all soils reaching K OC values of >8000. Finally, the significant retention of chlorothalonil and diazinon on Mollisols and Alfisols in spite of their low OC contents showed the contribution of clay minerals in the sorption process. PMID:25561264

  13. 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

  14. 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

  15. Preliminary measurements of gamma radiation in Chilean Antarctic Stations

    International Nuclear Information System (INIS)

    Natural and artificial gamma radiation, 1 m above the soil, is being investigated in 4 Chilean Antartic Stations. The measurements are performed with different types of TLD detectors. Preliminary results in the Tte. Marsh Station are reported and discussed. An average exposition of 3,5 μR/h was found during a 108 days period. This exposition corresponds to an annual dose of about 40 mrad, 8% of the annual dose limit for individual of the public. The presence of low energy artificial radioisotopes was not found. (Author)

  16. Ecosystem process interactions between central Chilean habitats

    Directory of Open Access Journals (Sweden)

    Meredith Root-Bernstein

    2015-01-01

    Full Text Available Understanding ecosystem processes is vital for developing dynamic adaptive management of human-dominated landscapes. We focus on conservation and management of the central Chilean silvopastoral savanna habitat called “espinal”, which often occurs near matorral, a shrub habitat. Although matorral, espinal and native sclerophyllous forest are linked successionally, they are not jointly managed and conserved. Management goals in “espinal” include increasing woody cover, particularly of the dominant tree Acacia caven, improving herbaceous forage quality, and increasing soil fertility. We asked whether adjacent matorral areas contribute to espinal ecosystem processes related to the three main espinal management goals. We examined input and outcome ecosystem processes related to these goals in matorral and espinal with and without shrub understory. We found that matorral had the largest sets of inputs to ecosystem processes, and espinal with shrub understory had the largest sets of outcomes. Moreover, we found that these outcomes were broadly in the directions preferred by management goals. This supports our prediction that matorral acts as an ecosystem process bank for espinal. We recommend that management plans for landscape resilience consider espinal and matorral as a single landscape cover class that should be maintained as a dynamic mosaic. Joint management of espinal and matorral could create new management and policy opportunities.

  17. 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 ...

  18. 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.

  19. 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

  20. 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...

  1. 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...

  2. 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...

  3. Detection of an organic-non volatile compound in variable-contaminated volcanic soil samples via Time Domain Reflectometry (TDR) technique: Preliminary results

    Science.gov (United States)

    comegna, alessandro; coppola, antonio; dragonetti, giovanna; chaali, nesrine; sommella, angelo

    2014-05-01

    Hydrocarbons may be present in soils as non-aqueous phase liquids (NAPLs), which means that these organic compounds, exist as a separate and immiscible phase with respect to water and air commonly present in the soil. NAPLs, which can be accidentally introduced in the environment (for example by waste disposal sites, industrial spills, gasoline stations, etc), constitutes a serious geo-environmental problem, given the toxicity level and the high mobility. Time domain reflectometry (TDR) has became, over several decades, an important technique for water estimation in soils. In order to expand the potentiality of the TDR technique, the main objective of this study is to explore the capacity of dielectric response to detect the presence of NAPLs in volcanic soils. In laboratory, soil samples were oven dried at 105° C and passed through a 2 mm sieve. Known quantities of soil, water and NAPL (corn oil, a non-volatile and non-toxic organic compound) were mixed and repacked into plastic cylinders (16 cm high and 9.5 cm in diameter); in order to obtain forty different volumetric combinations of water and oil (i.e. θfg = θwater + θNAPL), with θNAPL varying from 0.05 to 0.40 by 0.05 cm3/cm3 increments. Data collected were employed to implement a multiphase mixing model which permitted conversion from a dielectric permittivity domain into a θf domain and vice versa. The results of this study show that, the TDR device is NAPL-sensitive, especially for θf values greater than 0.20. Further works will be built on this initial study, concentrating on improving the dielectric response-database, in order to: i) enhancing the model efficiency in terms of NAPL capability detention, and ii) validating the developed TDR interpretation tool with field results.

  4. 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

  5. Sorption behavior of bensulfuron-methyl on andisols and ultisols volcanic ash-derived soils: Contribution of humic fractions and mineral-organic complexes

    Energy Technology Data Exchange (ETDEWEB)

    Espinoza, Jeannette; Fuentes, Edwar [Department of Inorganic and Analytical Chemistry, Faculty of Chemical and Pharmaceutical Sciences, University of Chile, Olivos 1007, Casilla 233, Santiago (Chile); Baez, Maria E., E-mail: mbaez@ciq.uchile.c [Department of Inorganic and Analytical Chemistry, Faculty of Chemical and Pharmaceutical Sciences, University of Chile, Olivos 1007, Casilla 233, Santiago (Chile)

    2009-12-15

    Bensulfuron-methyl sorption was studied in Andisol and Ultisol soils in view of their characteristic physical and chemical properties, presenting acidic pH and variable charge. Humic and fulvic acids (HA and FA) and humin (HUM) contributions were established. Sorption was studied by using two synthetic sorbents, an aluminum-silicate with iron oxide coverage and the same sorbent coated with humic acid. Freundlich model described Bensulfuron-methyl behavior in all sorbents (R{sup 2} 0.969-0.998). K{sub f} for soils (8.3-20.7 mug{sup 1-1/n} mL{sup 1/n} g{sup -1}) were higher than those reported in the literature. Organic matter, halloysite or kaolinite, and specific surface area contributed to the global process. The highest K{sub f} for HA, FA and HUM were 539.5, 82.9, and 98.7 mug{sup 1-1/n} mL{sup 1/n} g{sup -1}. Model sorbents described the participation of variable charge materials with high adsorption capacity. The constant capacitance model was used to assess effects of Bensulfuron-methyl adsorption on the distribution of SOH, SOH{sub 2}{sup +} and SO{sup -} sites of sorbents. - Organic matter, phyllosilicates, variable charge minerals and organo-mineral complexes contribute to bensulfuron-methyl sorption on volcanic ash-derived soils.

  6. Sorption behavior of bensulfuron-methyl on andisols and ultisols volcanic ash-derived soils: Contribution of humic fractions and mineral-organic complexes

    International Nuclear Information System (INIS)

    Bensulfuron-methyl sorption was studied in Andisol and Ultisol soils in view of their characteristic physical and chemical properties, presenting acidic pH and variable charge. Humic and fulvic acids (HA and FA) and humin (HUM) contributions were established. Sorption was studied by using two synthetic sorbents, an aluminum-silicate with iron oxide coverage and the same sorbent coated with humic acid. Freundlich model described Bensulfuron-methyl behavior in all sorbents (R2 0.969-0.998). Kf for soils (8.3-20.7 μg1-1/n mL1/n g-1) were higher than those reported in the literature. Organic matter, halloysite or kaolinite, and specific surface area contributed to the global process. The highest Kf for HA, FA and HUM were 539.5, 82.9, and 98.7 μg1-1/n mL1/n g-1. Model sorbents described the participation of variable charge materials with high adsorption capacity. The constant capacitance model was used to assess effects of Bensulfuron-methyl adsorption on the distribution of SOH, SOH2+ and SO- sites of sorbents. - Organic matter, phyllosilicates, variable charge minerals and organo-mineral complexes contribute to bensulfuron-methyl sorption on volcanic ash-derived soils.

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

    Science.gov (United States)

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

    2005-02-01

    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.

  8. 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

  9. Oceanography of the Chilean Patagonia

    Science.gov (United States)

    Pantoja, Silvio; Luis Iriarte, José; Daneri, Giovanni

    2011-03-01

    Chilean Patagonia is one of the most extended fjord regions in the world that covers nearly 240,000 km 2 with an extremely complex coastline and topography in one of the least densely populated areas of the country (1-8 inhabitants every 10 km 2). In recent years, the area has been undergoing somewhat intense pressure since several commercial projects in hydroelectricity, tourism, and commercial salmon and mytilid cultures have been developed, or are in progress. Concomitantly, several large research programs have been devised to study the physical, chemical, and biological environment of Patagonia, such as the CIMAR FIORDO, and recently COPAS Sur-Austral based at Universidad de Concepcion, that attempts to close the bridge between oceanographic knowledge and its use by society. In this introductory article we summarize the collection of papers comprising this Special Issue of Continental Shelf Research. These papers deal with aspects of regional oceanography and geology, inorganic and organic geochemistry, ecology of pelagic and benthic organisms, and past changes in productivity.

  10. Effect of climate and vegetation on soil organic carbon, humus fractions, allophanes, impolite, kaolinite, and oxyhydroxides in volcanic soils of Etna (Sicily)

    OpenAIRE

    Egli, Markus; Alioth, Ladina; Mirabella, Aldo; Raimondi, Salvatore; Nater, Markus; Verel, René

    2007-01-01

    A soil sequence along an elevational gradient ranging from subtropical to subalpine climate zones in the Etna region (Sicily, southern Italy) was investigated with respect to organic C, kaolinite, and crystalline to noncrystalline Al and Fe phases. Special emphasis was given to the stabilization of soil organic carbon (SOC) and its interaction with the inorganic phases. The soils were variations of Vitric Andosols that developed on a trachy-basaltic lava flow with an age of 15,000 years. Two ...

  11. 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)

  12. LA FRACCIÓN LIVIANA DE LA MATERIA ORGÁNICA DE UN SUELO VOLCÁNICO BAJO DISTINTO MANEJO AGRONÓMICO COMO ÍNDICE DE CAMBIOS DE LA MATERIA ORGÁNICA LÁBIL Soil light organic matter fraction of a volcanic soil under different agronomic management as an indicator of changes in labile organic matter

    Directory of Open Access Journals (Sweden)

    Erick Zagal

    2002-04-01

    Full Text Available Starting from an 18-year experiment with different crop rotations, samples of soil of volcanic origin from the foothills of Ñuble (37º09’ S lat.; 72º02’ W long. were obtained in order to determine the effect of agricultural management on light fraction (FL of the organic matter. FL was separated by density using NaI (d = 1,8 g cm-3. Carbon (C and nitrogen (N contents were determined by dry combustion both in the whole soil and the isolated FL. Light fraction contents were higher than those found in other research with non-volcanic soils. However, a clear trend to decrease FL was observed when soil use was intensified. The C or N proportions of the soil and the FL presented similar results. The use of this fraction as a sensitive indicator of changes in labile organic matter produced by different agricultural management is discussed.

  13. Charcoal and stable soil organic matter as indicators of fire frequency, climate and past vegetation in volcanic soils of Mt. Etna, Sicily

    OpenAIRE

    Egli, M.; Mastrolonardo, G; Seiler, Ruedi; Raimondi, S; Favilli, F; Crimi, V; Krebs, R; Cherubini, P; Certini, G.

    2012-01-01

    Charcoal fragments in soils are useful to reconstruct past vegetation because the level of preservation is often good enough to determine the tree genus. All forest ecosystems have the potential to burn as a result of naturally occurring or human-induced fires. Forest fires are coupled to climate and are a not-negligible factor of pedogenesis in Mediterranean areas, where they occur frequently. Furthermore, soil organic matter (SOM) is prone to undergo peculiar changes due to forest fires, bo...

  14. 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…

  15. Soil and river contamination patterns of chlordecone in a tropical volcanic catchment in the French West Indies (Guadeloupe).

    Science.gov (United States)

    Crabit, A; Cattan, P; Colin, F; Voltz, M

    2016-05-01

    The aim of this study was to identify primary flow paths involved in the chlordecone (CLD) river contamination and quantify the CLD fluxes to assess CLD pollution levels and duration according to a typical catchment of the banana cropping area in the French Indies (Guadeloupe): the Pérou Catchment (12 km(2)) characterized by heavy rainfall (5686 mm year(-1)). Three sub-catchments (SC1, SC2 and SC3) were studied during the hydrological year 2009-2010: a pedological survey combined with a spatialized hydrochemical approach was conducted. The average soil concentration is higher in the Pérou Catchment (3400 μg kg(-1)) than in the entire banana cropping area in Guadeloupe (2100 μg kg(-1)). The results showed that CLD stocks in soils vary largely among soil types and farming systems: the weakest stocks are located upstream in SC1 (5 kg ha(-1)), where a majority of the area is non-cultivated; medium stocks are located in Nitisols downstream in SC3 (9 kg ha(-1)); and the greatest stocks are observed in SC2 on Andosols (12 kg ha(-1)) characterized by large farms. The annual water balance and the hydro-chemical analysis revealed that the three sub-catchments exhibited different behaviors. Pérou River contamination was high during low flows, which highlighted that contamination primarily originated from groundwater contributions. The results showed that only a small part of the catchment (SC2), contributing little to the water flow, comprises a major CLD contribution, which is in agreement with the highly contaminated andosol soils observed there. Another significant result considers that at least 50 years would be required to export the totality of the actual CLD soil stocks retained in the topsoil layer. The actual time for soil remediation will however be much longer considering (i) the necessary time for the chlordecone to percolate and be stored in the shallow aquifers and (ii) its travel time to reach the river. PMID:27039897

  16. 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

  17. 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.

  18. 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...

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

    OpenAIRE

    M Mora-Carreño; Briones, R.; JS Galecio; Parra, D.; Rosenfeld, C.; SCHMEISSER, A.; B Menarim

    2014-01-01

    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 pre...

  20. 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

  1. 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

  2. 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.

  3. 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...

  4. 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

  5. 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.

  6. 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.

  7. 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

  8. Kraft mill sludge to improve vegetal production in Chilean Andisol.

    Science.gov (United States)

    Gallardo, F; Mora, M L; Diez, M C

    2007-01-01

    The effect of kraft mill sludge addition (25 to 75 ton/ha) to soil derived from volcanic ashes (Andisol) on wheat (Triticum aestivum L.cv. Puken) biomass production, and in the nutrient absorption by the plants was evaluated. Respiration activity and seed germination tests were carried out on the soil/sludge mixtures, in order to evaluate possible toxic effects due to the sludge addition to the soil. Soil without sludge was used as a control treatment. The plants were grown in a greenhouse (25 degrees C, 14 h-photoperiod) during 120 days, then the plants were collected and dried at 65 degrees C for 72 h for the determination of biomass production (root and aerial) and analyzed for mineral content (Ca, Mg, K and P). The mixtures of soil/sludge showed no toxicity. Seed germination and respiration activity increased with the increment of the sludge. The accumulated CO2 in the soil without sludge was 41.66 mg CO2/100; this value shows a low microbial activity. The biomass increased with the increment of sludge addition to the soil and five times more biomass was obtained when 75 ton/ha sludge was added to the soil. The nutrient absorption efficiency was also improved with the sludge addition. PMID:17486832

  9. 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…

  10. 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...... four years of operation, CHASE has produced more than 130 supernovae, being the most successful project of its type in the southern hemisphere. Here we describe the project and present illustrative examples of CHASE discoveries of particular relevance....

  11. The Lathrop Wells volcanic center

    International Nuclear Information System (INIS)

    The Lathrop Wells volcanic center is located 20 km south of the potential Yucca Mountain site, at the south end of the Yucca Mountain range. This paper discusses a detailed Study Plan which was prepared describing planned geochronology and field studies to assess the chronology of the Lathrop Wells volcanic center and other Quaternary volcanic centers in the region. A paper was published discussing the geomorphic and soil evidence for a late Pleistocene or Holoceno age for the main cone of the center. The purpose of this paper was to expose the ideas concerning the age of the Lathrop Wells center to scientific scrutiny. Additionally, field evidence was described suggesting the Lathrop Wells center may have formed from multiple eruptive events with significant intervals of no activity between events. This interpretation breaks with established convention in the volcanological literature that small volume basalt centers are monogenetic

  12. 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

  13. 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

    OpenAIRE

    Cecilia María Armas Herrera; Juan Luis Mora Hernández; Carmen Dolores Arbelo Rodríguez; Antonio Rodríguez Rodríguez

    2013-01-01

    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 ...

  14. 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.

  15. 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.

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

    OpenAIRE

    Amador Paola; Obregón Ana M; Cataldo Rodrigo; Domínguez-Vásquez Patricia; Smalley Susan V; González Andrea; Ho-Urriola Judith A; Santos José L; Weisstaub Gerardo; Hodgson M Isabel

    2011-01-01

    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 ...

  17. 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, ...

  18. 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

  19. 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.

  20. 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

  1. MINERALOGÍA Y GENESIS DE ALGUNOS SUELOS DE CENIZAS VOLCÁNICAS DE CHILOÉ CONTINENTAL, CHILE Mineralogy and origin of some volcanic ash soils of continental Chiloé, Chile

    Directory of Open Access Journals (Sweden)

    Eduardo Besoain M.

    2000-04-01

    Full Text Available Se estudiaron cuatro Andisoles provenientes de los volcanes Hornopirén y Hualaihué o volcán Apagado, situados en Chiloé Continental, provincia de Palena, X Región (41º 53’S. Los suelos están localizados en las faldas de los volcanes, en un relieve abrupto cubierto con una densa foresta pluvial, muy húmeda, de 4.000 a 5.000 mm de precipitación anual, y temperatura media anual de 10ºC. Se describió la morfología de los suelos y se determinaron sus propiedades químicas, físicas y mineralógicas. Los pediones son profundos y sus variaciones texturales sugieren la participación de varios episodios eruptivos. Todos los suelos se caracterizan por tener un horizonte A grueso, con elevado contenido de materia orgánica (12-25% C-orgánico, valores elevados a moderados de retención de agua a 1500 kPa, altos valores de retención de fósforo (>90%, con la excepción de los horizontes sub-superficiales del suelo Pululil. La CIC es moderada a alta y la saturación de bases es muy baja. El contenido de vidrios volcánicos es muy alto (59-88% y tiende a aumentar con la profundidad del perfil; la mayoría de los vidrios tienen burbujas. Los coloides de los suelos son alofánicos, pero en la superficie prevalecen los complejos Al, Fe-húmicos. Sílice opalina también se encuentra en el horizonte A de todos los pediones. Los suelos satisfacen las propiedades ándicas y pertenecen al Orden de los Andisoles, suborden de los Udands.Four andisols from volcanoes Hornopirén and Hualaihué or Apagado, located in continental Chiloé, X Region (41º 53’S were studied. The soils are located on the slopes of the volcanoes, on a very steep elevation covered with dense rain forest. The local climate averages 4,000 -- 5,000 mm annual rainfall and a mean annual temperature of 10ºC. The soils were described morphologically and their chemical, physical and mineralogical properties were determined. The horizons are deep and their textural variation suggests

  2. A Feminine Touch : Gender and Civil-Military Relations in the Chilean Armed Forces

    OpenAIRE

    Gundersrud, Synne Høie

    2015-01-01

    This analysis explores the extent to which gender equality exists within the Chilean military institutions. A clear political and legal space has been created for equality to grow in Chile, and many advances in Chilean politics demonstrate progress in terms of expanding the gender equality agenda in Chilean society. However, my analysis indicates that traditional and discriminatory ideas of gender, dominating the culture of the Chilean Armed Forces, are limiting the social process of integrat...

  3. 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.

  4. 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)

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

    International Nuclear Information System (INIS)

    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 (Koc). 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, Koc 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.

  6. Variación de la capacita tampón en suelos derivados de cenizas volcánicas Variation of the buffer capacity in soils derived from volcanic ashes

    Directory of Open Access Journals (Sweden)

    Dante Pinochet T.

    2005-03-01

    Full Text Available Con el objetivo de evaluar la variación de un mismo tipo de suelo a la adición de cal, se realizó un estudio en muestras seleccionadas de suelos derivados de cenizas volcánicas. Los parámetros evaluados fueron: variación del pH inicial (4,76 a 5,03, contenido inicial de bases de intercambio (2,3 a 8,3 cmol+ kg-1 y el contenido de materia orgánica (11,6 a 26,8 g 100 g-1. El nivel inicial de pH y materia orgánica afectaron los parámetros de acidez del suelo evaluados (capacidad tampón, Ca intercambiable y contenido de Al intercambiable. Para propósitos agronómicos, se determinó que por cada gramo de CaCO3 aplicado por kilogramo de suelo, el pH aumentó 0,2 unidades, el contenido de Ca intercambiable aumentó en un 70% y el contenido de Al intercambiable disminuyó en un 50% de su valor previo, y que existe una variación de la capacidad tampón de pH y del contenido de Ca intercambiable en los suelos dependiendo del contenido de materia orgánica.To evaluate the variation of the same type of soils to liming, a study was carried out in selected soil samples from soils derived from volcanic ashes. The parameters evaluated were the variation of initial pH (4.76 to 5.03, the initial content of exchangeable bases (2.3 to 8.3 cmol+ kg-1 and organic matter content (11.6 to 26.8 g 100 g-1. The initial pH level and organic matter affected the soil acidity parameters evaluated (buffering capacity, exchangeable Ca and exchangeable Al content. For agronomic purposes, it was established that for each gram of CaCO3 applied to a kilogram of soil, the pH is increased 0.2 units, exchangeable Ca content increased 70%, and the exchangeable Al content decreased to 50% of its previous value, and there is a pH buffering capacity and exchangeable Ca content in the evaluated soils dependent on its organic matter content.

  7. 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

  8. Geologic reconnaissance of Lautaro Volcano, Chilean Patagonia

    Directory of Open Access Journals (Sweden)

    Akihisa Motoki

    2006-01-01

    Full Text Available Lautaro is the volcano closest to the Chile Triple Junction in the Andean Austral Volcanic Zone. The volcanic edifice of 3,607 m a.s.l. stands out on the north-western part of the plateau of the South Patagonian Ice Field. The volcano basement is composed of low-grade meta-pelites that are cut by tabular intrusive bodies of hornblende-biotite granite. The volcano is almost completely covered by ice and the study was performed on volcanic detritus present in terminal moraines of the Lautaro Glacier and the tephra on the surface of the O'Higgins Glacier. The terminal moraines of Lautaro Glacier contain fragments of light grey dacite rich in plagioclase and hornblende phenocrysts. Some dacite blocks show prismatic jointing, suggesting an origin of hot emplacement and subsequent rapid cooling, possibly resulted from collapse of a steep lava front. Some samples have glassy groundmass and rhyolite-like flow texture, with presence of mafic inclusions and bread crust bomb texture. The surface of the O'Higgins Glacier is covered by lapilli-size pumice fallout deposit. There are many dirt cones covered by volcanic ash composed of pumice fragments, volcanic glass, quartz, plagioclase, biotite, hornblende, and orthopyroxene. The ash and pumice are similar in chemical composition, both indicating an adakitic signature. At least three layers of fallout deposits have been recognised in parts of the surface of the glacier, which may correspond to the latest known eruptionsReconocimiento geológico del volcán Lautaro, Patagonia chilena. El volcán Lautaro es el más próximo al Punto Triple de la dorsal de Chile en la Zona Volcánica Austral de los Andes. El edificio volcánico de 3.607 m s.n.m. se destaca como el punto más alto en la parte noroeste del plateau del Campo de Hielo Patagónico Sur. El basamento del volcán está compuesto por metapelitas de bajo grado metamórfico que están atravesadas por cuerpos tabulares constituidos por granitos de

  9. 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

  10. A critical review of the Chilean civil nuclear liability regime

    International Nuclear Information System (INIS)

    This article reviews the Chilean civil nuclear liability regime. The Nuclear Security Act (Law 18.302), enacted in 1984, and the Vienna Convention on Civil Liability for Nuclear Damage, ratified ed by Chile in 1989, are the fundamental laws of the current regime. Although Chile has no nuclear power plants, it is still important to analyze how the Chilean legislation would protect citizens from nuclear damages. This paper does not consider the policy reasons for and against the promotion of atomic energy. Rather, it critically examines the current status of the Chilean nuclear regime. Undoubtedly, if in the future Chile chooses to include nuclear sources in its energy mix, it will not be enough to introduce some isolated legal amendments, but it will be necessary to build a new Chilean Energy Regime which includes nuclear energy. In that scenario, though, it will be useful to know and understand how the current nuclear liability regime works. From this point of view, the reforms this article proposes to the current nuclear liability regime might be helpful to academics and policy makers alike

  11. 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.

  12. 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...

  13. 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

  14. 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

  15. 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.

  16. Azufre Elemental como Corrector del pH y la Fertilidad de Alfunos Suelos de la III y IV Región de Chile Elemental Sulphur as pH and Soil Fertility Amendment for Some Chileans Soils of Regions III and IV

    Directory of Open Access Journals (Sweden)

    Carlos Sierra B

    2007-06-01

    Full Text Available En los suelos de la zona norte de Chile existen suelos con carbonatos, situación que influye sobre la disponibilidad de nutrientes para los cultivos. En el presente experimento se evaluó en condiciones de laboratorio, el efecto de la aplicación de azufre elemental sobre el pH, conductividad eléctrica y micronutrientes en seis suelos de la III y IV Región, Chile. El azufre se aplicó en dosis de 500 y 1000 mg S° kg-1, y el suelo se incubó por períodos de 60 y 120 días a 80% de su capacidad de campo a 25°C. El experimento se estableció con un diseño de tratamientos completamente al azar con arreglo factorial, donde los factores fueron: suelo, dosis de azufre elemental y tiempo de incubación. Los recipientes en incubación se distribuyeron de acuerdo a un diseño completamente al azar. Las características de los suelos que más influyeron sobre la magnitud del efecto acidificante del azufre elemental fueron los contenidos de CaCO3, materia orgánica y arena. Las reducciones de pH significativas se presentaron en los suelos con una menor capacidad tampón, como consecuencia del menor contenido de CaCO3 y materia orgánica. La conductividad eléctrica se incrementó por la aplicación del azufre elemental, debido al aumento de sales solubles en el suelo. Los niveles de los micronutrientes Fe, Mn y Cu se incrementaron en los suelos cuyos pH disminuyeron significativamente, siendo el Mn el más influenciado por la acidificación. Esta información es de utilidad para establecer programas de aplicación de enmiendas en suelos calcáreos de la zona norte de ChileSoils containing calcite are common in Northern Chile, and this condition decreases the availability of nutrients for plants. The effect of the application of elemental sulphur (S° was evaluated on soil pH, electrical conductivity and the available micronutrients content in six soils of the III and IV Regions of Chile. This was applied in doses of 500 and 1000 mg S° kg-1 and the

  17. Modeling the sorption kinetic of metsulfuron-methyl on Andisols and Ultisols volcanic ash-derived soils: kinetics parameters and solute transport mechanisms.

    Science.gov (United States)

    Cáceres, Lizethly; Escudey, Mauricio; Fuentes, Edwar; Báez, María E

    2010-07-15

    Metsulfuron-methyl sorption kinetic was studied in Andisol and Ultisol soils in view of their distinctive physical and chemical properties: acidic pH and variable surface charge. Different kinetic models were applied to the experimental results. The pseudo-second-order model fitted sorption kinetics data better than the pseudo-first-order model. The rate constant and the initial rate constant values obtained through this model demonstrated the different behavior of metsulfuron-methyl in both kinds of soils, both parameters being the highest for Andisol. The application of Elovich equation, intraparticle diffusion model and a two-site nonequilibrium model (TSNE) allowed to conclude that: (i) the high organic matter content is the governing factor for Andisols where mass transfer across the boundary layer, and in a lesser degree, intraparticle diffusion were the two processes controlling sorption kinetic and (ii) the mineral composition was more relevant in Ultisols where rate was controlled almost exclusively by intraparticle diffusion into macropores and micropores. The slower sorption rate on Ultisols, the mechanism involved and the lower sorption capacity of this kind of soils must be taken into account to assess leaching behavior of this herbicide. PMID:20399011

  18. Soils

    International Nuclear Information System (INIS)

    For Austria there exists a comprehensive soil data collection, integrated in a GIS (geographical information system). The content values of pollutants (cadmium, mercury, lead, copper, mercury, radio-cesium) are given in geographical charts and in tables by regions and by type of soil (forests, agriculture, greenland, others) for the whole area of Austria. Erosion effects are studied for the Austrian region. Legal regulations and measures for an effective soil protection, reduction of soil degradation and sustainable development in Austria and the European Union are discussed. (a.n.)

  19. Holocene volcanic geology, volcanic hazard, and risk on Taveuni, Fiji

    International Nuclear Information System (INIS)

    The Holocene volcanic geology of Taveuni has been mapped in order to produce a volcanic hazard and risk assessment for the island. Taveuni is the third-largest island of the Fiji group and home to 14,500 people. At least cubic km 2.7 of olivine-alkali-basalt magma was erupted from over 100 events throughout the Holocene. Vents are concentrated along a northeast-striking rift zone that is parallel to other regional structural trends. There is an overall trend of younging southward along the rift. Holocene lavas and tephras are grouped within six newly defined eruptive periods, established on a basis of radiocarbon dating. Within these periods, 14 tephra layers, useful as local marker horizons, are recognised. At least 58% of Holocene eruptions produced lava flows, while almost all produced some tephra. Individual eruption event volumes ranged between 0.001 and cubic km 0.20 (dense rock equivalent). Many eruptions involved at least some phases of phreatic and/or phreato-magmatic activity, although dominant hydrovolcanic activity was limited to only a few events. A volcanic hazard map is presented, based on the Holocene geology map and statistical analyses of eruption recurrence. The highest levels of ground-based and near-vent hazards are concentrated along the southern portion of the island's rift axis, with the paths of initial lava flows predicted from present topography. Tephra fall hazards are based on eruption parameters interpreted from mapped Holocene tephra layers. Hawaiian explosive-style eruptions appear to be a dominant eruptive process, with prevailing low-level (<3 km) southeasterly winds dispersing most tephra to the northwestern quadrant. Vulnerable elements (population centres, infrastructure, and economy) on Taveuni have been considered in deriving a volcanic risk assessment for the island. A number of infrastructural and subdivision developments are either under way or planned for the island, driven by its highly fertile soils and availability of

  20. Prokaryotic diversity pattern in high-altitude ecosystems of the Chilean Altiplano

    Science.gov (United States)

    Demergasso, Cecilia; Dorador, Cristina; Meneses, Daniela; Blamey, Jenny; Cabrol, Nathalie; Escudero, Lorena; Chong, Guillermo

    2010-06-01

    The Chilean Altiplano is the westernmost part of a large volcanic-sedimentary plateau in the central Andes. High solar irradiance and rapid increase of temperature have contributed to make it a hot spot of global climatic change. In this study, we describe microbial diversity in the summit lake of the Simba volcano (5,870 m) and the evaporitic basins of Salar de Aguas Calientes (4,200 m) and Laguna Lejía (4,325 m) using both culture and culture-independent methods. The results obtained were analyzed together with available information from related environments to describe the traits of the microbial community driven by main environmental factors. Isolated cultures exhibit high resistance to all three types of UV radiation, further supporting the adaptation of microorganisms to the high altitude environment. The microbial community structures at Salar de Aguas Calientes and Laguna Lejía are similar to those from other saline systems and cold environments where Bacteroidetes is the major bacterial group. The abundance of sequences related to alphaproteobacteria and methanogenic populations likely reflects the importance of aerobic anoxigenic phothosynthesis and the cycling of one-carbon compounds in the high altitude lake ecosystems. Geochemistry and microbial communities at Simba as well as those reported in the Licancabur summit lake provide evidence for sulfur-rich environments but under different conditions. Those differences between neighboring mountain lake ecosystems highlight the effect of volcanic activity on microbial communities. The hypothetical ecosystem model described in this work provides a clue to follow the microbial community responses to geophysical environment coupled with rapid climate change.

  1. 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

  2. Biogeochemistry of REE elements and tetrad effect in the soil-plant system: a study on volcanic rock covers in southernmost Brazil

    Directory of Open Access Journals (Sweden)

    Maria do Carmo Lima e Cunha

    2012-12-01

    Full Text Available This paper deals with the distribution of REE in rock, soil and plant in an area of monzonitic rocks from southernmost Brazil. The REE patterns in Schinus lensticifolius show a negative-Ce anomaly and a prominent tetrad effect, characterized as W-type that are not present in rock and soil samples. The REE patterns in the soils and rocks sampled are very similar and there is no fractionation of REE during the processes of soil formation. The W-type patterns are interpreted as indicating that REE were absorved by S. lentiscifolius as simple ions rather than as complex ions, or, alternatively, that the transport of REE in the plant metabolic processes was as free ions. The recognition of tetrads, either, M- or W-type patterns, is an additional tool for understanding the biogeochemistry of REE and can contribute to the study of monitoring processes of contaminated environment or to mineral prospecting.Este trabalho trata da distribuição dos ETR na rocha, solo e planta em área de ocorrência de rochas monzoníticas do extremo sul do Brasil. O padrão dos ETR em Schinus lentiscifolius apresenta anomalia negativa de Ce e significativo efeito tétrade, do tipo W, ausente no padrão da rocha e do solo. A configuração das curvas da rocha e do solo é similar e sem fracionamento das ETR durante a pedogênese. O padrão em W é interpretado como decorrente da absorção dos ETR pela planta na forma de íons livres e não complexados, ou, alternativamente, que o transporte das ETR nos processos metabólicos foi na forma de íons livres. O reconhecimento de tétrades, seja do tipo W ou M, é uma ferramenta adicional na compreensão da biogeoquímica dos ETR e pode contribuir para o estudo de processos de monitoramento de ambientes contaminados ou para pesquisas em prospecção mineral.

  3. 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

  4. Sorption behavior of bensulfuron-methyl on andisols and ultisols volcanic ash-derived soils: contribution of humic fractions and mineral-organic complexes.

    Science.gov (United States)

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

    2009-12-01

    Bensulfuron-methyl sorption was studied in Andisol and Ultisol soils in view of their characteristic physical and chemical properties, presenting acidic pH and variable charge. Humic and fulvic acids (HA and FA) and humin (HUM) contributions were established. Sorption was studied by using two synthetic sorbents, an aluminum-silicate with iron oxide coverage and the same sorbent coated with humic acid. Freundlich model described Bensulfuron-methyl behavior in all sorbents (R(2) 0.969-0.998). K(f) for soils (8.3-20.7 microg(1-1/n) mL(1/n) g(-1)) were higher than those reported in the literature. Organic matter, halloysite or kaolinite, and specific surface area contributed to the global process. The highest K(f) for HA, FA and HUM were 539.5, 82.9, and 98.7 microg(1-1/n) mL(1/n) g(-1). Model sorbents described the participation of variable charge materials with high adsorption capacity. The constant capacitance model was used to assess effects of Bensulfuron-methyl adsorption on the distribution of SOH, SOH(2)(+) and SO(-) sites of sorbents. PMID:19608318

  5. 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.

  6. 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...

  7. The social and cultural impact of advertising among Chilean youths

    OpenAIRE

    Maite Rodríguez Salineros; Enrique Vergara Leyton

    2010-01-01

    This paper 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 ...

  8. 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...

  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 analyzed. (author). Refs, figs and tabs

  10. 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)

  11. 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)

  12. 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...

  13. 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...

  14. Environmental and climatic changes in Central Chilean Patagonia since the Late Glacial (Mallín El Embudo, 44° S

    Directory of Open Access Journals (Sweden)

    M. E. de Porras

    2013-10-01

    Full Text Available Multi-millennial environmental and climatic changes in Central Chilean Patagonia (44–49° S during the Last Glacial–Interglacial cycle have been of particular interest as changes in the position and strength of the Southern Westerlies are the major forcing factor conditioning the environmental dynamics. Recent attempts to reconstruct regional environmental and climatic signals from Central Chilean Patagonia reveal some discrepancies and unclear issues among the records. This paper presents the 13 ka pollen and charcoal records from Mallín El Embudo (44°40' S; 71°42' W located in the deciduous Nothofagus forest in the middle Río Cisnes valley. The paper aims to (1 establish the timing and magnitude of local vegetation changes and fire activity since the Late Glacial and (2 integrate these results at the regional scale in order to discuss the discrepancies and depict the Central Chilean Patagonia environmental and climatic dynamics since Late Glacial. Open landscapes dominated by grasses associated with scattered Nothofagus forest patches dominated middle Río Cisnes valley between 13–11.2 ka suggesting low effective moisture but also reflecting that landscape configuration after glacial retreat was still ongoing. At 11.2 ka, a sudden development of an open and quite dynamic Nothofagus forest probably associated to the synchronous high fire activity occurred suggesting a rise in effective moisture. Since 9.5 ka, the record reflects the presence of a closed Nothofagus forest related to higher/similar effective moisture conditions than before but under an unmarked precipitation seasonality. The forest experienced a slight canopy opening since 5.7 ka, probably due to slightly drier conditions than before followed by a sudden change around 4.2 ka associated with fire and volcanic disturbances. The recovery of an open Nothofagus forest related to slight wetter conditions (similar to present occurred around 2 ka and persisted under highly

  15. 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

  16. Volcanic Eruptions in Kamchatka

    Science.gov (United States)

    2007-01-01

    [figure removed for brevity, see original site] [figure removed for brevity, see original site] Sheveluch Stratovolcano Click on the image for full resolution TIFF Klyuchevskoy Stratovolcano Click on the image for full resolution TIFF One of the most volcanically active regions of the world is the Kamchatka Peninsula in eastern Siberia, Russia. It is not uncommon for several volcanoes to be erupting at the same time. On April 26, 2007, the Advanced Spaceborne Thermal Emission and Reflection Radioneter (ASTER) on NASA's Terra spacecraft captured these images of the Klyuchevskoy and Sheveluch stratovolcanoes, erupting simultaneously, and 80 kilometers (50 miles) apart. Over Klyuchevskoy, the thermal infrared data (overlaid in red) indicates that two open-channel lava flows are descending the northwest flank of the volcano. Also visible is an ash-and-water plume extending to the east. Sheveluch volcano is partially cloud-covered. The hot flows highlighted in red come from a lava dome at the summit. They are avalanches of material from the dome, and pyroclastic flows. With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER images Earth to map and monitor the changing surface of our planet. ASTER is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra spacecraft. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. The broad spectral coverage and high spectral resolution of ASTER provides scientists in numerous disciplines with critical information for surface mapping, and monitoring of dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats; monitoring potentially active volcanoes; identifying crop stress; determining cloud morphology and

  17. 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.

  18. Unravel biophysical factors on river water quality response in Chilean Central-Southern watersheds.

    Science.gov (United States)

    Yevenes, Mariela A; Arumí, José L; Farías, Laura

    2016-05-01

    Identifying the key anthropogenic (land uses) and natural (topography and climate) biophysical drivers affecting river water quality is essential for efficient management of water resources. We tested the hypothesis that water quality can be predicted by different biophysical factors. Multivariate statistics based on a geographical information system (GIS) were used to explore the influence of factors (i.e., precipitation, topography, and land uses) on water quality (i.e., nitrate (NO 3 (-) ), phosphate (PO 4 (3 -) ), silicate (Si(OH)4), dissolved oxygen (DO), suspended solids (TSS), biological oxygen demand (DO), temperature (T), conductivity (EC), and pH) for two consecutive years in the Itata and Biobío river watersheds, Central Chile (36° 00' and 38° 30'). The results showed that (NO 3 (-) ), (PO 4 (3 -) ), Si(OH)4, TSS, EC, and DO were higher during rainy season (austral fall, winter, and spring), whereas BOD and temperature were higher during dry season. The spatial variation of these parameters in both watersheds was related to land use, topography (e.g., soil moisture, soil hydrological group, and erodability), and precipitation. Soil hydrological group and soil moisture were the strongest explanatory predictors for PO 4 (3 -) , Si(OH)4 and EC in the river, followed by land use such as agriculture for NO 3 (-) and DO and silviculture for TSS and Si(OH)4. High-resolution water leaching and runoff maps allowed us to identify agriculture areas with major probability of water leaching and higher probability of runoff in silviculture areas. Moreover, redundancy analysis (RDA) revealed that land uses (agriculture and silviculture) explained in 60 % the river water quality variation. Our finding highlights the vulnerability of Chilean river waters to different biophysical drivers, rather than climate conditions alone, which is amplified by human-induced degradation. PMID:27038616

  19. Chilean Family Reminiscing about Emotions and Its Relation to Children's Self-Regulation Skills

    Science.gov (United States)

    Leyva, Diana; Nolivos, Virginia

    2015-01-01

    Research Findings: This study examined the relation between Chilean parents' narrative participatory styles (i.e., the way in which parents scaffold children's participation in conversations) and children's self-regulation skills. A total of 210 low-income Chilean parent-child dyads participated in the study. Dyads were videotaped talking about a…

  20. Radiogeochemistry of Kamchatka soils

    Science.gov (United States)

    Zakharikhina, L. V.; Litvinenko, Yu. S.

    2016-01-01

    Background concentrations of Th and U in volcanic soils (Andosols) of Kamchatka are much lower than their clarkes in continental soils. The dose rate of gamma radiation above the soil surface (10-11.5 µR/h in the south and 8-9.5 [m]R/h in the north of Kamchatka Peninsula) is lower than the natural level of this index for the mountainous areas in the boreal zone of Russia. The natural radiogeochemical background of Kamchatka soils is controlled by the petrochemical composition of volcanic ash composing the mineral basis of Kamchatka soils. It is higher in the southern soil province, where soils develop from acidic ashes, in comparison with the northern province, with a predominance of soils developing from ashes of basic and intermediate composition. This agrees with Th and U clarkes for the corresponding types of volcanic rocks and explains the natural origin of the elevated radiogeochemical background in the southern part of Kamchatka as compared with its northern part. The soils of the northern province developing from relatively fresh volcanic ashes show a lower Th/U ratio as compared to the soils of southern Kamchatka because of higher uranium content in the newly deposited ashes.

  1. Cluster analysis of elemental constituents of individual atmospheric aerosol particles from the volcanic plume of Lonquimay eruption in 1989

    International Nuclear Information System (INIS)

    Aerosol samples collected around the Chilean site Lonquimay during major volcanic activities in January 1989 have been subjected to microPIXE measurements of 1 μm lateral resolution in the Debrecen Institute. Elemental concentrations relative to calcium have been determined for Al, Si, P, S, K, Sc, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, and Ba in 187 individual aerosol particles with the particle sizes between 15 μm and 1 μm. On the basis of a cluster analysis performed on the data set we defined eight clusters. Scatter plots for selected pairs of elements as Si/Al, K/Si, S/Cl, and Al/S elemental ratios that are considered as signatures characterizing types and mechanisms in volcanic eruption - have been compared with published data available in the literature for various volcanic sites. (author)

  2. Volcanism in Eastern Africa

    Science.gov (United States)

    Cauthen, Clay; Coombs, Cassandra R.

    1996-01-01

    In 1891, the Virunga Mountains of Eastern Zaire were first acknowledged as volcanoes, and since then, the Virunga Mountain chain has demonstrated its potentially violent volcanic nature. The Virunga Mountains lie across the Eastern African Rift in an E-W direction located north of Lake Kivu. Mt. Nyamuragira and Mt. Nyiragongo present the most hazard of the eight mountains making up Virunga volcanic field, with the most recent activity during the 1970-90's. In 1977, after almost eighty years of moderate activity and periods of quiescence, Mt. Nyamuragira became highly active with lava flows that extruded from fissures on flanks circumscribing the volcano. The flows destroyed vast areas of vegetation and Zairian National Park areas, but no casualties were reported. Mt. Nyiragongo exhibited the same type volcanic activity, in association with regional tectonics that effected Mt. Nyamuragira, with variations of lava lake levels, lava fountains, and lava flows that resided in Lake Kivu. Mt. Nyiragongo, recently named a Decade volcano, presents both a direct and an indirect hazard to the inhabitants and properties located near the volcano. The Virunga volcanoes pose four major threats: volcanic eruptions, lava flows, toxic gas emission (CH4 and CO2), and earthquakes. Thus, the volcanoes of the Eastern African volcanic field emanate harm to the surrounding area by the forecast of volcanic eruptions. During the JSC Summer Fellowship program, we will acquire and collate remote sensing, photographic (Space Shuttle images), topographic and field data. In addition, maps of the extent and morphology(ies) of the features will be constructed using digital image information. The database generated will serve to create a Geographic Information System for easy access of information of the Eastem African volcanic field. The analysis of volcanism in Eastern Africa will permit a comparison for those areas from which we have field data. Results from this summer's work will permit

  3. 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)

  4. 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.

  5. [The Chilean Health Care System: the task ahead].

    Science.gov (United States)

    Goic, Alejandro

    2015-06-01

    The most important event in Chilean public health in the XXth Century was the creation of the National Health Service (NHS), in 1952. Systematic public policies for the promotion of health, disease prevention, medical care, and rehabilitation were implemented, while a number of more specific programs were introduced, such as those on infant malnutrition, complementary infant feeding, medical control of pregnant women and healthy infants, infant and adult vaccination, and essential sanitation services. In 1981, a parallel private health care system was introduced in the form of medical care financial institutions, which today cover 15% of the population, as contrasted with the public system, which covers about 80%. From 1952 to 2014, public health care policies made possible a remarkable improvement in Chile's health indexes: downward trends in infant mortality rate (from 117.8 to 7.2 x 1,000 live births), maternal mortality (from 276 to 18.5 x 100,000), undernourished children schooling, and years of primary school education, were significantly improved as well. Nevertheless, compared with OECD countries, Chile has a relatively low public investment in health (45.7% of total national investment), a deficit in the number of physicians (1.7 x 1,000 inhabitants) and nurses (4.8 x 1,000), in the number of hospital beds (2.1 x 1,000), and in the availability of generic drugs in the market (30%). Chile and the USA are the two OECD countries with the lowest public investment in health. A generalized dissatisfaction with the current Chilean health care model and the need of the vast majority of the population for timely access to acceptable quality medical care are powerful arguments which point to the need for a universal public health care system. The significant increase in public expenditure on health care which such a system would demand requires a sustainable growth of the Chilean economy. PMID:26230561

  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. 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...

  8. 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.

  9. The origin of brines and salts in Chilean salars: a hydrochemical review

    Science.gov (United States)

    Risacher, François; Alonso, Hugo; Salazar, Carlos

    2003-11-01

    Northern Chile is characterized by a succession of north-south-trending ranges and basins occupied by numerous saline lakes and salt crusts, collectively called salars. Fossil salt crusts are found to the west in the extremely arid Central Valley, while active salars receiving permanent inflows fill many intravolcanic basins to the east in the semiarid Cordillera. Sea salts and desert dust are blown eastward over the Cordillera, where they constitute an appreciable fraction of the solute load of very dilute waters (salt contentsalars. Saline lakes and subsurface brines are under steady-state regime. The average residence time of conservative components ranges from a few years to some thousands years, which indicates a permanent leakage of the brines through bottom sediments. The infiltrating brines are recycled in the hydrologic system where they mix with dilute meteoric waters. High heat flow is the likely driving force that moves the deep waters in this magmatic arc region. Active Chilean salars cannot be considered as terminal lakes nor, strictly speaking, as closed basin lakes. Almost all incoming salts leave the basin and are transported elsewhere. Moreover, the dissolution of fossil salt crusts in some active salars also carries away important fluxes of components in percolating brines. Evaporative concentration of inflow waters leads to sulfate-rich or calcium-rich, near-neutral brines. Alkaline brines are almost completely lacking. The alkalinity/calcium ratio of inflow waters is lowered by the oxidation of native sulfur (reducing alkalinity) and the deposition of eolian gypsum (increasing Ca concentration). Theoretically, SO 4-rich inflow waters and their derived SO 4-rich brines should be found in the intravolcanic basins of the Cordillera because of the ubiquity of native sulfur, while Ca-rich brines should prevail in sedimentary basins where Ca-rich minerals are abundant. This relation is perfectly observed in the salar de Atacama, the largest in Chile

  10. 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...

  11. [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

  12. Microfaunal primary succession on the volcanic island Surtsey

    DEFF Research Database (Denmark)

    Frederiksen, Helle B.; Kraglund, H. O.; Ekelund, F.

    2001-01-01

    The island of Surtsey, Iceland, was formed in 1963 by a volcanic eruption. Since then, it has served as a unique natural laboratory for scientists interested in primary succession. In this study we investigated the state of the soil microfauna succession in 1995. We examined locations on the island...

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

    International Nuclear Information System (INIS)

    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. 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. 

  15. 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...

  16. 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)

  17. 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.

  18. 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.

  19. 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

  20. Mealybug species from Chilean agricultural landscapes and main factors influencing the genetic structure of Pseudococcus viburni

    OpenAIRE

    Correa, Margarita C.G.; Eric Lombaert; Thibaut Malausa; Didier Crochard; Andrés Alvear; Tania Zaviezo; Ferran Palero

    2015-01-01

    The present study aimed to characterize the distribution of mealybug species along Chilean agro-ecosystems and to determine the relative impact of host plant, management strategy, geography and micro-environment on shaping the distribution and genetic structure of the obscure mealybug Pseudococcus viburni. An extensive survey was completed using DNA barcoding methods to identify Chilean mealybugs to the species level. Moreover, a fine-scale study of Ps. viburni genetic diversity and populatio...

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

    OpenAIRE

    Marcelo Cano-Cappellacci; Fernanda Aleitte Leyton; Joshua Durán Carreño

    2016-01-01

    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 ...

  2. The congressional Committee System of the Chilean Legislature, 1834-1924

    OpenAIRE

    Iván Mauricio Obando Camino

    2011-01-01

    This is a historical, institutional study about the congressional committee system of the Chilean legislature from 1834 through 1924. This study uses a longitudinal perspective to focus on committee origins, functions, processes, and authority. It shows that the Chilean legislature developed a committee system early by taking stock of previous, short-lived congressional experiences and trial-and-error. Congressional committees dealt with bill drafting, housekeeping matters, and bureaucratic o...

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

    OpenAIRE

    Cianelli, Rosina; Ferrer, Lilian; MCELMURRY, BEVERLY J.

    2008-01-01

    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, fift...

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

    OpenAIRE

    Javier Moraga

    2014-01-01

    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), Revis...

  5. The politics of the Chilean right from the Popular Front to 1964

    OpenAIRE

    Correa, Sofía

    1994-01-01

    The right in Chile has been crucial to the democratic politics of the country ever since the development of the party system. In the period covered by this thesis (1939- 1964) the Chilean right faced the combined challenge of reformist governments and the emergence of mass political parties on the left. This thesis describes the Chilean right as being composed by political parties, entrepreneurial associations and a leading newspaper, El Mercurio. which represented an...

  6. 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...

  7. Effect of slaughter methods on the quality of Chilean jack mackerel (Trachurus murphyi) during refrigerated storage

    OpenAIRE

    Lyu, Fei; Huang, Rui-Ji; Liu, Lin; Zhou, Xuxia; Ding, Yu-Ting

    2013-01-01

    The main objective of this study was to assess the influence of slaughter methods on the quality of Chilean jack mackerel (Trachurus murphyi) during refrigerated storage on board. Fishes were slaughtered by asphyxia in air (AA), asphyxia in ice water (AI) or stunning fish heads (SH), and the rigor mortis, pH, total volatile basic nitrogen (TVB-N), trimethylamine (TMA), 2-thiobarbituric acid reactive substances (TBARS) and sensory properties for the fishes were analyzed. On day 0, Chilean jack...

  8. 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...

  9. 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

  10. 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.

  11. 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

  12. 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...

  13. System of Volcanic activity

    Directory of Open Access Journals (Sweden)

    P. HÉDERVARI

    1972-06-01

    Full Text Available A comparison is made among the systems of B. G.
    Escher (3, of R. W. van Bemmelen (1 and that of the author (4. In this
    connection, on the basis of Esclier's classification, the terms of "constructiv
    e " and "destructive" eruptions are introduced into the author's system and
    at the same time Escher's concept on the possible relation between the depth
    of magma-chamber and the measure of the gas-pressure is discussed briefly.
    Three complementary remarks to the first paper (4 011 the subject of system
    of volcanic activity are added.

  14. 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)

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

    DEFF Research Database (Denmark)

    Søager, Nina

    The extensive Quaternary volcanism in the Payenia volcanic province, Mendoza, Argentina, is investigated in this study by major and trace element analyses, Sr, Nd, Hf and Pb-isotopic analyses and Zr-Hf isotope dilution data on samples from almost the entire province. The samples are mainly...... basalts from all the studied volcanic fields in Payenia is signs of lower crustal contamination indicating assimilation of, in some cases, large amounts of trace element depleted, mafic, plagioclase-bearing rocks. The northern Payenia is dominated by backarc basalts erupted between late Pliocene to late...... 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 are...

  16. 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.

  17. 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.

  18. 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.

  19. 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

  20. 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

  1. 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

  2. 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.

  3. Revealing latitudinal patterns of mitochondrial DNA diversity in Chileans.

    Science.gov (United States)

    Gómez-Carballa, Alberto; Moreno, Fabián; Álvarez-Iglesias, Vanesa; Martinón-Torres, Federico; García-Magariños, Manuel; Pantoja-Astudillo, Jaime A; Aguirre-Morales, Eugenia; Bustos, Patricio; Salas, Antonio

    2016-01-01

    The territory of Chile is particularly long and narrow, which combined with its mountainous terrain, makes it a unique scenario for human genetic studies. We obtained 995 control region mitochondrial DNA (mtDNA) sequences from Chileans representing populations living at different latitudes of the country from the North to the southernmost region. The majority of the mtDNA profiles are of Native American origin (∼88%). The remaining haplotypes are mostly of recent European origin (∼11%), and only a minor proportion is of recent African ancestry (∼1%). While these proportions are relatively uniform across the country, more structured patterns of diversity emerge when examining the variation from a phylogeographic perspective. For instance, haplogroup A2 reaches ∼9% in the North, and its frequency decreases gradually to ∼1% in the southernmost populations, while the frequency of haplogroup D (sub-haplogroups D1 and D4) follows the opposite pattern: 36% in the southernmost region, gradually decreasing to 21% in the North. Furthermore, there are remarkable signatures of founder effects in specific sub-clades of Native American (e.g. haplogroups D1j and D4p) and European (e.g. haplogroups T2b3 and K1a4a1a+195) ancestry. We conclude that the magnitude of the latitudinal differences observed in the patterns of mtDNA variation might be relevant in forensic casework. PMID:26517175

  4. 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.

  5. Natural activity of 40K in some Chilean building materials

    International Nuclear Information System (INIS)

    Knowledge of the natural level of radioactivity is important to assess the influence of gamma radiation exposure in building materials. The main sources of external radiation exposure in buildings are members of the uranium and thorium decay chains and 40K occurring naturally in building materials, which emit gamma rays.The specific activity of building materials has been reported for many countries. However, for Chilean building materials no such data are available. A study of 40K speciactivity on building materials was carried out with gamma spectrometric system based on high-purity germanium detector. The 40K activity was measured directly by its own gamma-ray line at 1460.8 keV. Samples of gypsum, cement, brick and cement and gravel mixture, widely used in Chile, were used on this work. The samples were corrected by moisture content and the geometrical conditions has been normalized to avoid volumetric corrections. All preliminary results are below the world average of 500 Bq/kg for building materials reported by UNSCEAR

  6. 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.

  7. 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

  8. 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.

  9. 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.

  10. 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

  11. Detecting Volcanism on Extrasolar Planets

    CERN Document Server

    Kaltenegger, L; Sasselov, D D

    2010-01-01

    The search for extrasolar rocky planets has already found the first transiting rocky super-Earth, Corot 7b, with a surface temperature that allows for magma oceans. Here we ask if we could distinguish rocky planets with recent major volcanism by remote observation. We develop a model for volcanic eruptions on an Earth-like exoplanet based on the present day Earth, derive the observable features in emergent and transmission spectra for multiple scenarios of gas distribution and cloudcover. We calculate the observation time needed to detect explosive volcanism on exoplanets in primary as well as secondary eclipse and discuss the likelihood of observing volcanism on transiting Earth to super-Earth sized exoplanets. We find that sulfur dioxide from large explosive eruptions does present a spectral signal that is remotely detectable especially for secondary eclipse measurements around the closest stars using ground based telescopes, and report the frequency and magnitude of the expected signatures. Transit probabi...

  12. 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.

  13. Monogenetic volcanic hazards and assessment

    Science.gov (United States)

    Connor, C.; Connor, L. J.; Richardson, J. A.

    2012-12-01

    Many of the Earth's major cities are build on the products of monogenetic volcanic eruptions and within geologically active basaltic volcanic fields. These cities include Mexico City (Mexico), Auckland (New Zealand), Melbourne (Australia), and Portland (USA) to name a few. Volcanic hazards in these areas are complex, and involve the potential formation of new volcanic vents and associated hazards, such as lava flows, tephra fallout, and ballistic hazards. Hazard assessment is complicated by the low recurrence rate of volcanism in most volcanic fields. We have developed a two-stage process for probabilistic modeling monogenetic volcanic hazards. The first step is an estimation of the possible locations of future eruptive vents based on kernel density estimation and recurrence rate of volcanism using Monte Carlo simulation and accounting for uncertainties in age determinations. The second step is convolution of this spatial density / recurrence rate model with hazard codes for modeling lava inundation, tephra fallout, and ballistic impacts. A methodology is presented using this two-stage approach to estimate lava flow hazard in several monogenetic volcanic fields, including at a nuclear power plant site near the Shamiram Plateau, a Quaternary volcanic field in Armenia. The location of possible future vents is determined by estimating spatial density from a distribution of 18 mapped vents using a 2-D elliptical Gaussian kernel function. The SAMSE method, a modified asymptotic mean squared error approach, uses the distribution of known eruptive vents to optimally determine a smoothing bandwidth for the Gaussian kernel function. The result is a probability map of vent density. A large random sample (N=10000) of vent locations is drawn from this probability map. For each randomly sampled vent location, a lava flow inundation model is executed. Lava flow input parameters (volume and average thickness) are determined from distributions fit to field observations of the low

  14. Volcanic eruption plumes on Io

    International Nuclear Information System (INIS)

    The detection of an umbrella-shaped plume extending about 280 km above the bright limb of Io was one of the most important discoveries made during the Voyager 1 encounter with the jovian system. This discovery proves that Io is volcanically active at present, and the number and magnitude of these eruptions indicate that Io is the most volcanically active body so far discovered in the Solar System. Preliminary analyses of these eruptive plumes are presented. (U.K.)

  15. 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

  16. Timing of the magmatism of the paleo-Pacific border of Gondwana: U-Pb geochronology of Late Paleozoic to Early Mesozoic igneous rocks of the north Chilean Andes between 20o and 31oS

    International Nuclear Information System (INIS)

    U-Pb zircon geochronological data provide record of about 130 Ma of igneous activity in the Andes of northern Chile, which extended episodically from the latest Early Carboniferous to Early Jurassic (328-194 Ma). The overall U-Pb data show that volcanism and plutonism were essentially synchronous and major episodes of igneous activity developed during the Late Carboniferous to Mid-Permian (310 to 260 Ma) and from Late Permian to Late Triassic (255-205 Ma), with less prominent episodes in the mid-Carboniferous (330 to 320 Ma), and Early Jurassic (200-190 Ma). Thus, from the Carboniferous to the Early Triassic dominantly silicic magmatism developed along the Chilean segment of the southwestern border of Gondwana supercontinent. Further magmatism developed during the Mid-Late Triassic (250-194 Ma) was bimodal and synchronous with rift-related, continental and/or marine sedimentary strata related to the early stages of break-up of Gondwana. Most of the silicic volcanic rocks of the Precordillera and Domeyko Cordillera of northern Chile (21o 30o to 25o30oS) are older than the silicic rocks assigned to the Choiyoi succession in Argentina, being instead equivalent in age to Carboniferous to Early Permian marine sedimentary sequences present in the eastern Argentinean foreland. On the other hand, silicic volcanic successions exposed in the easternmost part of northern Chile are equivalent in age to the Choiyoi succession of the San Rafael Block of Argentina. An eastward expansion or migration of the volcanism during the Mid-Permian to Early Triassic is inferred, interpretation that is consistent with expansion of the volcanism at that time in Argentina. The timing of the Late Paleozoic to Early Jurassic magmatism is coincident with that of the Andes of Peru and of western Argentina according to the available U-Pb data, revealing a rather consistent evolution in time of the magmatism along the southwestern, paleo-Pacific border of Gondwana

  17. 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.

  18. 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

  19. 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…

  20. 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.…

  1. The Class and Culture-Based Exclusion of the Chilean Neoliberal Educational Reform

    Science.gov (United States)

    Cavieres, Eduardo A.

    2011-01-01

    In this article I analyze the class- and cultural-based exclusion produced by the Chilean neoliberal educational reform, carried out during the period from 1990 to 2010. This educational reform follows the same neoliberal model applied to the economy of the country. Although some indicators improved in relation to coverage and public spending in…

  2. Uneven Distribution of Novice Teachers in the Chilean Primary School System

    Science.gov (United States)

    Meckes, Lorena; Bascope, Martin

    2012-01-01

    This study examines the allocation of novice primary teachers in Chilean schools, looking at their characteristics and at the attributes of the schools at which they are hired after having completed their initial teacher training. The study reveals that in Chile, more qualified novice teachers are more prone to get jobs in socio-economically…

  3. 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…

  4. 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…

  5. 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

  6. 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

  7. 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

  8. 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.

  9. 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. PMID:20368458

  10. 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.

  11. 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

  12. 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.

  13. 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

  14. 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.

  15. Volcanic eruption detection with TOMS

    Science.gov (United States)

    Krueger, Arlin J.

    1987-01-01

    The Nimbus 7 Total Ozone Mapping Spectrometer (TOMS) is designed for mapping of the atmospheric ozone distribution. Absorption by sulfur dioxide at the same ultraviolet spectral wavelengths makes it possible to observe and resolve the size of volcanic clouds. The sulfur dioxide absorption is discriminated from ozone and water clouds in the data processing by their spectral signatures. Thus, the sulfur dioxide can serve as a tracer which appears in volcanic eruption clouds because it is not present in other clouds. The detection limit with TOMS is close to the theoretical limit due to telemetry signal quantization of 1000 metric tons (5-sigma threshold) within the instrument field of view (50 by 50 km near the nadir). Requirements concerning the use of TOMS in detection of eruptions, geochemical cycles, and volcanic climatic effects are discussed.

  16. Volcanic eruptions and solar activity

    Science.gov (United States)

    Stothers, Richard B.

    1989-01-01

    The historical record of large volcanic eruptions from 1500 to 1980 is subjected to detailed time series analysis. In two weak but probably statistically significant periodicities of about 11 and 80 yr, the frequency of volcanic eruptions increases (decreases) slightly around the times of solar minimum (maximum). Time series analysis of the volcanogenic acidities in a deep ice core from Greenland reveals several very long periods ranging from about 80 to about 350 yr which are similar to the very slow solar cycles previously detected in auroral and C-14 records. Solar flares may cause changes in atmospheric circulation patterns that abruptly alter the earth's spin. The resulting jolt probably triggers small earthquakes which affect volcanism.

  17. Volcanism in southern Guinevere Planitia, Venus: Regional volcanic history and morphology of volcanic domes

    Science.gov (United States)

    Crown, David A.; Stofan, Ellen R.; Plaut, Jeffrey J.

    1993-01-01

    Guinevere Planitia is a low-lying region located between the highlands of Beta Regio and Eistla Regio. Analyses of Pioneer Venus, Goldstone, and Arecibo radar data suggested that the surface of Guinevere Planitia is dominated by volcanism, primarily in the form of bright, dark, and mottled plains units. Also identified in this region was the Beta-Eistla Deformation Zone, composed of ovoids and discontinuous segments of lineament belts that have been embayed by the surrounding plains. The resolution of Magellan SAR images allows detailed investigations of the volcanic deposits found in the area in order to determine the types of eruptive activity which have occurred and to constrain the regional volcanic history. Analyses of an area of southern Guinevere Planitia between 0-25 deg N and 300-330 deg indicate the presence of a wide variety of volcanic land forms, including large shield volcanoes, widespread plains, lava flow fields, and small domes, cones, and shields as well as coronae and other circular structures that have associated volcanic deposits.

  18. 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.

  19. 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

  20. 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.

  1. 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.

  2. 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

  3. 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

  4. Recent progress in volcanism studies: Site characterization activities for the Yucca Mountain site characterization project

    International Nuclear Information System (INIS)

    Significant progress has been made on volcanism studies over the past calendar year. There are a number of major highlights from this work. Geochronology data have been obtained for the Lathrop Wells center using a range of isotopic, radiogenic, and age-calibrated methods. Initial work is encouraging but still insufficient to resolve the age of the center with confidence. Geologic mapping of the Sleeping Butte volcanic centers was completed and a report issued on the geology and chronology data. Twenty shallow trenches have been constructed in volcanic units of the Lathrop Wells volcanic center. Results of detailed studies of the trenches support a polycyclic eruptive history. New soil data from the trenches continue to support a late Pleistocene or Holocene age for many of the volcanic units at the center. Geochemical data (trace element and isotopic analysis) show that the volcanic units of the Lathrop Wells center cannot be related to one another by fractional crystallization of a single magma batch, supporting a polycyclic model of volcanism. Structural models using existing data are used to evaluate the probability of magmatic disruption of a potential repository. Several permissive models have been developed but none lead to significant differences in calculating the disruption ratio. Work was initiated on the eruptive and subsurface effects of magmatic activity on a repository. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

    Perry, F.V. [New Mexico Univ., Albuquerque, NM (United States). Dept. of Geology; Crowe, B.M. [Los Alamos National Lab., NM (United States)

    1991-12-31

    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.

  6. 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.

  7. Mealybug species from Chilean agricultural landscapes and main factors influencing the genetic structure of [i]Pseudococcus viburni[/i

    OpenAIRE

    Correa, Margarita C.G.; Lombaert, Eric; Malausa, Thibaut; Crochard, Didier; Alvear, Andrés; Zaviezo, Tania; Palero, Ferran

    2015-01-01

    The present study aimed to characterize the distribution of mealybug species along Chilean agro-ecosystems and to determine the relative impact of host plant, management strategy, geography and micro-environment on shaping the distribution and genetic structure of the obscure mealybug Pseudococcus viburni. An extensive survey was completed using DNA barcoding methods to identify Chilean mealybugs to the species level. Moreover, a fine-scale study of Ps. viburni genetic diversity and populatio...

  8. 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...

  9. 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...

  10. 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

  11. 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: ...

  12. DETECTING VOLCANISM ON EXTRASOLAR PLANETS

    International Nuclear Information System (INIS)

    The search for extrasolar rocky planets has already found the first transiting rocky super-Earth, Corot 7b, with a surface temperature that allows for magma oceans. Here, we investigate whether we could distinguish rocky planets with recent major volcanism by remote observation. We develop a model for volcanic eruptions on an Earth-like exoplanet based on the present-day Earth and derive the observable features in emergent and transmission spectra for multiple scenarios of gas distribution and cloud cover. We calculate the observation time needed to detect explosive volcanism on exoplanets in primary as well as secondary eclipse and discuss the likelihood of observing volcanism on transiting Earth-sized to super-Earth-sized exoplanets. We find that sulfur dioxide from large explosive eruptions does present a spectral signal that is remotely detectable especially for secondary eclipse measurements around the closest stars and ground-based telescopes, and report the frequency and magnitude of the expected signatures. The transit probability of a planet in the habitable zone decreases with distance from the host star, making small, nearby host stars the best targets.

  13. 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.

  14. 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.

  15. Descartes region - Evidence for Copernican-age volcanism.

    Science.gov (United States)

    Head, J. W., III; Goetz, A. F. H.

    1972-01-01

    A model that suggests that the high-albedo central region of the Descartes Formation was formed by Copernican-age volcanism was developed from Orbiter photography, Apollo 12 multispectral photography, earth-based spectrophotometry, and thermal IR and radar data. The bright surface either is abundant in centimeter-sized rocks or is formed from an insulating debris layer overlying a surface with an abundance of rocks in the 1- to 20-cm size range. On the basis of these data, the bright unit is thought to be a young pyroclastic deposit mantling older volcanic units of the Descartes Formation. Since the Apollo 16 target point is only 50 km NW of the central part of this unit, evidence for material associated with this unique highland formation should be searched for in returned soil and rock samples.

  16. Sustaining volcanism in Central Kamchatka

    Science.gov (United States)

    Nikulin, Alex

    Flux-induced melting in the mantle wedge acts as the driving mechanism of arc volcanism in subduction zone environments. The primary control on the geographical position of arc volcanic centers is the depth of the subducting plate beneath the overriding plate. Globally, the average depth to the subducting plate beneath volcanic arcs is estimated at ˜100km. Volcanoes of the Central Kamchatka Depression in Eastern Russia comprise the most active volcanic arc system in the world with the depth of the subducting Pacific plate beneath the arc estimated at 180-200km, greatly in excess of the global average. In my research I attempt to describe the special tectonic circumstances that explain the deviation of the subduction depth constraint on arc volcanism in Central Kamchatka. In my study I rely on geophysical and geochemical data and petrological modeling to propose a new geodynamic model to explain voluminous volcanic activity in Central Kamchatka. In the initial stage of the study I conducted a geophysical investigation using receiver function methodology to map and describe the contact of the subducting Juan de Fuca Plate in the well-instrumented Cascadia subduction zone. I calculated and compiled a database of receiver function profiles from stations along the extent of the Cascadia forearc and mapped a low velocity anisotropic zone proposed to be serpentinized material along the forearc axis. In the second stage of my study I applied a similar methodology to describe the sub-crustal structure of Central Kamchatka. Results of this effort suggested presence of a low-velocity zone in the upper mantle separate from the subducting Pacific plate. I proceeded to investigate the tectonic origin of this feature in the final stage of my dissertation work with the use of receiver function migration, geochemical analysis and petrological modeling. I was able to further constrain the position of the low velocity anomaly and derive geochemical and petrological evidence linking

  17. 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.

  18. "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

  19. Lead isotopes tracing weathering and atmospheric deposition in a small volcanic catchment

    Science.gov (United States)

    Négrel, Philippe; Petelet-Giraud, Emmanuelle; Guerrot, Catherine; Millot, Romain

    2015-09-01

    Lead isotopes were studied in soil and sediments of the small volcanic catchment in the Massif Central (France), a large area of Tertiary to Recent continental alkaline volcanism. The comparison of Pb and K (normalized to Zr) shows a linear evolution of weathering processes, whereby lead enrichment from atmospheric deposition is a major contributor explaining the deviation of several points from this line. A box model simulates the lead evolution in sediments from soil production on the hillslopes due to bedrock weathering and from anthropogenic input through atmospheric deposition and constrains the dynamics of sediment transfer. Lead isotope ratios decrease from bedrock to sediment and soil without any clear relationship when compared to lead contents. Pb isotopic compositions showed that most of the lead budget in sediment and soil results from bedrock weathering with influence of gasoline-additive-lead and past mining activities derived inputs, but no lead input from agricultural activity.

  20. DATA PROTECTION AS BOUNDARY TO THE RIGHT TO ACCESS INFORMATION UNDER CHILEAN LAW

    Directory of Open Access Journals (Sweden)

    Gladys Camacho Cépeda

    2014-06-01

    Full Text Available On April 20, 2009, the Transparency Act entered into force in Chile, ensuring citizens the access to public information. Although the balance of this system is positive, it is important to analyse the heart of conflicts which arise when needing to reconcile legal interests and rights guarded by Chilean law, such as the protection of privacy and personal data. The paper analyses the status of the protection of personal data in the Chilean legal system. Firstly, it argues that the right to protection of personal data transcends the classical division between public and private scope, because in both fields it needs to be guarded. Secondly, the abstract seeks to contribute to the debate for the construction of performance standards for public organizations to enable reconciling transparency with the protection of personal data.

  1. 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

  2. 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)

  3. The reliability of morphometric discriminant functions in determining the sex of Chilean flamingos Phoenicopterus chilensis

    OpenAIRE

    Diego MONTALTI et al

    2012-01-01

    Monomorphic birds cannot be sexed visually and discriminant functions on the basis of external morphological variations are frequently used. Our objective was to evaluate the reliability of sex classification functions created from structural measurements of Chilean flamingos Phoenicopterus chilensis museum skins for the gender assignment of live birds. Five measurements were used to develop four discriminant functions: culmen, bill height and width, tarsus length and middle toe claw. The fun...

  4. 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

  5. Postnatal Growth Patterns in a Chilean Cohort: The Role of SES and Family Environment

    OpenAIRE

    Kang Sim, D. E.; S. Gahagan; Martinez, S.; Blanco, E.; Lozoff, B.; Cappiello, M; Castillo, M

    2012-01-01

    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 a...

  6. 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...

  7. 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 ...

  8. 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...

  9. 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...

  10. 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...

  11. Corporate Social Responsibility in the Chilean Salmon Industry : Institutional Foundations and other Explanatory Factors

    OpenAIRE

    2006-01-01

    The objective of the present thesis is to achieve a better understanding of CSR in a cross country context. It bases itself on a qualitative case study of the Chilean salmon industry with emphasis on the Norwegian companies that operate herein. The main theoretical framework is taken from organization theory, and bases itself on the rational and the normative institutional organization perspectives. The main goal is to identify the explanatory factors for the CSR measures in this industry. A ...

  12. Pilot Testing an Internet-Based STI and HIV Prevention Intervention With Chilean Women

    Science.gov (United States)

    Villegas, Natalia; Santisteban, Daniel; Cianelli, Rosina; Ferrer, Lilian; Ambrosia, Todd; Peragallo, Nilda; Lara, Loreto

    2015-01-01

    Purpose The incidence of sexually transmitted infections (STIs) and human immunodeficiency virus (HIV) is high among young Chilean women, and there are no STI or HIV prevention interventions available to them that incorporate technology. The purpose of this study was to investigate the preliminary efficacy of an Internet-based STI and HIV prevention intervention (I-STIPI) for Chilean young women on measures of STI- and HIV-related information, motivation, behavioral skills, and preventive behaviors. Design This is a pretest-posttest study. Forty young Chilean women between 18 and 24 years of age participated in an investigation of the I-STIPI’s preliminary efficacy on STI and HIV prevention-related outcomes between baseline and a postintervention assessment. The intervention consisted of four online modules. Data collection was conducted in Santiago, Chile. Paired-samples t test analysis was used to determine whether there were significant differences in each of the outcome variables. Findings After receiving I-STIPI, women reported a significant increase in levels of STI- and HIV-related knowledge, attitudes toward the use of condoms and perceived self-efficacy, and a reduction of risky sexual behaviors with uncommitted partners. Conclusions The I-STIPI showed promise as an Internet-based intervention that can reduce barriers to accessing preventive interventions and increase STI and HIV preventive behaviors in young Chilean women. Clinical Relevance The study provided important information about the ability of an Internet-based intervention to reduce young women’s risk factors and to provide positive preliminary efficacy on STI- and HIV-related outcomes. Internet-based interventions can eliminate many barriers to receiving prevention interventions and may prove to be cost effective. PMID:25410132

  13. The Chilean Labor Market: Job Creation, Quality, Inclusiveness, and Future Challenges

    OpenAIRE

    Parro, Francisco; Reyes, Loreto

    2013-01-01

    This paper analyzes recent labor market developments in the Chilean economy. The evidence shows a booming labor market with strong job creation since 2010. Most of the jobs created during the past three years are quality jobs—that is, jobs with a written contract and whose employers have made the corresponding payments toward pensions, healthcare, and unemployment insurance. We show that a combination of economic growth and specific policies seems to be the driving force behind the strong cre...

  14. 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...

  15. 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.

  16. 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...

  17. 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...

  18. Understanding Attitudes and Pro-Environmental Behaviors in a Chilean Community

    OpenAIRE

    Nicolás C. Bronfman; Pamela C. Cisternas; Esperanza López-Vázquez; Cristóbal de la Maza; Juan Carlos Oyanedel

    2015-01-01

    Environmental protection and restoration are some of the major challenges faced by our society. To address this problem, it is fundamental to understand pro-environmental behaviors in the population, as well as the factors that determine them. There are, however, very few studies conducted in Latin America that are focused in understanding the environmental behavior of its citizens. The main goal of this research was to study the environmental behaviors of a Chilean community and identify the...

  19. 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. ...

  20. 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...

  1. 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 ...

  2. 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...

  3. Revision of the Chilean species of Empididae (Diptera described by J. Macquart

    Directory of Open Access Journals (Sweden)

    José A. Rafael

    Full Text Available Four Chilean species of Empididae (Diptera are revised: Aplomera pachymera (Macquart, 1838, A. gayi Macquart, 1838, Empis nudipes Macquart, 1838 and E. polita Macquart, 1838. Aplomera chilensis (Bezzi, 1909 was also studied and it is being considered junior synonym of A. pachymera. Empis nudipes Macquart, 1838 is confirmed to be a junior synonym of A. gayi Macquart, 1838. Lectotype is being designated for A. pachymera, A. chilensis and E. polita. Illustration of terminalia and photomicrographs of wings are also included.

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

    OpenAIRE

    Fischer, M. A.; Van der velde, 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 extend this description, paying special attention to the morphology, anatomy and histology of the digestive and reproductive system. Furthermore, new data on the morphology of the central nervous s...

  5. 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...

  6. 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.

  7. 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...

  8. 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

  9. Mealybug species from Chilean agricultural landscapes and main factors influencing the genetic structure of Pseudococcus viburni.

    Science.gov (United States)

    Correa, Margarita C G; Lombaert, Eric; Malausa, Thibaut; Crochard, Didier; Alvear, Andrés; Zaviezo, Tania; Palero, Ferran

    2015-01-01

    The present study aimed to characterize the distribution of mealybug species along Chilean agro-ecosystems and to determine the relative impact of host plant, management strategy, geography and micro-environment on shaping the distribution and genetic structure of the obscure mealybug Pseudococcus viburni. An extensive survey was completed using DNA barcoding methods to identify Chilean mealybugs to the species level. Moreover, a fine-scale study of Ps. viburni genetic diversity and population structure was carried out, genotyping 529 Ps. viburni individuals with 21 microsatellite markers. Samples from 16 localities were analyzed using Bayesian and spatially-explicit methods and the genetic dataset was confronted to host-plant, management and environmental data. Chilean crops were found to be infested by Ps. viburni, Pseudococcus meridionalis, Pseudococcus longispinus and Planococcus citri, with Ps. viburni and Ps. meridionalis showing contrasting distribution and host-plant preference patterns. Ps. viburni samples presented low genetic diversity levels but high genetic differentiation. While no significant genetic variance could be assigned to host-plant or management strategy, climate and geography were found to correlate significantly with genetic differentiation levels. The genetic characterization of Ps. viburni within Chile will contribute to future studies tracing back the origin and improving the management of this worldwide invader. PMID:26559636

  10. 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.

  11. 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.

  12. HMGCR rs17671591 SNP Determines Lower Plasma LDL-C after Atorvastatin Therapy in Chilean Individuals.

    Science.gov (United States)

    Cuevas, Alejandro; Fernández, César; Ferrada, Luis; Zambrano, Tomás; Rosales, Alexy; Saavedra, Nicolás; Salazar, Luis A

    2016-04-01

    Lipid-lowering response to statin therapy shows large interindividual variability. At a genome-wide significance level, single nucleotide polymorphisms (SNPs) in PCSK9 and HMGCR have been implicated in this differential response. However, the influence of these variants is uncertain in the Chilean population. Hence, we aimed to evaluate the contribution of PCSK9 rs7552841 and HMGCR rs17671591 SNPs as genetic determinants of atorvastatin response in Chilean hypercholesterolaemic individuals. One hundred and one hypercholesterolaemic patients received atorvastatin 10 mg/day for 4 weeks. Plasma lipid profile (TC, HDL-C, LDL-C and TG) was determined before and after statin treatment, and SNPs were identified by allelic discrimination using TaqMan(®) SNP Genotyping Assays. Adjusted univariate and multivariate analyses' models were used for statistical analyses, and a p-value atorvastatin therapy for the PCSK9 variant. However, the HMGCR rs17671591 T allele contributed to basal HDL-C concentration variability along with a higher increase in this lipid fraction after statin medication. In addition, this allele determined greater plasma LDL-C reductions after therapy with atorvastatin. Our data suggest that the HMGCR rs17671591 polymorphism can constitute a genetic marker of lower plasma LDL-C and enhanced HDL-C concentration after atorvastatin therapy in the Chilean population. PMID:26408409

  13. [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

  14. 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.

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

    Science.gov (United States)

    Cano-Cappellacci, Marcelo; Leyton, Fernanda Aleitte; Carreño, Joshua Durán

    2016-01-01

    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. PMID:26815160

  16. 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...

  17. 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...

  18. Can rain cause volcanic eruptions?

    Science.gov (United States)

    Mastin, Larry G.

    1993-01-01

    Volcanic eruptions are renowned for their violence and destructive power. This power comes ultimately from the heat and pressure of molten rock and its contained gases. Therefore we rarely consider the possibility that meteoric phenomena, like rainfall, could promote or inhibit their occurrence. Yet from time to time observers have suggested that weather may affect volcanic activity. In the late 1800's, for example, one of the first geologists to visit the island of Hawaii, J.D. Dana, speculated that rainfall influenced the occurrence of eruptions there. In the early 1900's, volcanologists suggested that some eruptions from Mount Lassen, Calif., were caused by the infiltration of snowmelt into the volcano's hot summit. Most such associations have not been provable because of lack of information; others have been dismissed after careful evaluation of the evidence.

  19. 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.

  20. 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

  1. 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

  2. Atmospheric chemistry in volcanic plumes

    OpenAIRE

    von Glasow, Roland

    2010-01-01

    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...

  3. 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.

  4. Volcanism in Elysium Planitia, Mars

    Science.gov (United States)

    Mouginis-Mark, P. J.

    1984-04-01

    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.

  5. 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.

  6. 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.

  7. Soil radon response around an active volcano

    International Nuclear Information System (INIS)

    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

  8. 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.

  9. Disruptive event analysis: volcanism and igneous intrusion

    Energy Technology Data Exchange (ETDEWEB)

    Crowe, B.M.

    1980-08-01

    An evaluation is made of the disruptive effects of volcanic activity with respect to long term isolation of radioactive waste through deep geologic storage. Three major questions are considered. First, what is the range of disruption effects of a radioactive waste repository by volcanic activity. Second, is it possible, by selective siting of a repository, to reduce the risk of disruption by future volcanic activity. And third, can the probability of repository disruption by volcanic activity be quantified. The main variables involved in the evaluation of the consequences of repository disruption by volcanic activity are the geometry of the magma-repository intersection (partly controlled by depth of burial) and the nature of volcanism. Potential radionuclide dispersal by volcanic transport within the biosphere ranges in distance from several kilometers to global. Risk from the most catastrophic types of eruptions can be reduced by careful site selection to maximize lag time prior to the onset of activity. Certain areas or volcanic provinces within the western United States have been sites of significant volcanism and should be avoided as potential sites for a radioactive waste repository. Examples of projection of future sites of active volcanism are discussed for three areas of the western United States. Probability calculations require two types of data: a numerical rate or frequency of volcanic activity and a numerical evaluation of the areal extent of volcanic disruption for a designated region. The former is clearly beyond the current state of art in volcanology. The latter can be approximated with a reasonable degree of satisfaction. In this report, simplified probability calculations are attempted for areas of past volcanic activity.

  10. Disruptive event analysis: volcanism and igneous intrusion

    International Nuclear Information System (INIS)

    An evaluation is made of the disruptive effects of volcanic activity with respect to long term isolation of radioactive waste through deep geologic storage. Three major questions are considered. First, what is the range of disruption effects of a radioactive waste repository by volcanic activity. Second, is it possible, by selective siting of a repository, to reduce the risk of disruption by future volcanic activity. And third, can the probability of repository disruption by volcanic activity be quantified. The main variables involved in the evaluation of the consequences of repository disruption by volcanic activity are the geometry of the magma-repository intersection (partly controlled by depth of burial) and the nature of volcanism. Potential radionuclide dispersal by volcanic transport within the biosphere ranges in distance from several kilometers to global. Risk from the most catastrophic types of eruptions can be reduced by careful site selection to maximize lag time prior to the onset of activity. Certain areas or volcanic provinces within the western United States have been sites of significant volcanism and should be avoided as potential sites for a radioactive waste repository. Examples of projection of future sites of active volcanism are discussed for three areas of the western United States. Probability calculations require two types of data: a numerical rate or frequency of volcanic activity and a numerical evaluation of the areal extent of volcanic disruption for a designated region. The former is clearly beyond the current state of art in volcanology. The latter can be approximated with a reasonable degree of satisfaction. In this report, simplified probability calculations are attempted for areas of past volcanic activity

  11. Contemporary habitat discontinuity and historic glacial ice drive genetic divergence in Chilean kelp

    Directory of Open Access Journals (Sweden)

    Spencer Hamish G

    2010-07-01

    Full Text Available Abstract Background South America's western coastline, extending in a near-straight line across some 35 latitudinal degrees, presents an elegant setting for assessing both contemporary and historic influences on cladogenesis in the marine environment. Southern bull-kelp (Durvillaea antarctica has a broad distribution along much of the Chilean coast. This species represents an ideal model taxon for studies of coastal marine connectivity and of palaeoclimatic effects, as it grows only on exposed rocky coasts and is absent from beaches and ice-affected shores. We expected that, along the central Chilean coast, D. antarctica would show considerable phylogeographic structure as a consequence of the isolating effects of distance and habitat discontinuities. In contrast, we hypothesised that further south - throughout the region affected by the Patagonian Ice Sheet at the Last Glacial Maximum (LGM - D. antarctica would show relatively little genetic structure, reflecting postglacial recolonisation. Results Mitochondrial (COI and chloroplast (rbcL DNA analyses of D. antarctica from 24 Chilean localities (164 individuals revealed two deeply divergent (4.5 - 6.1% for COI, 1.4% for rbcL clades from the centre and south of the country, with contrasting levels and patterns of genetic structure. Among populations from central Chile (32° - 44°S, substantial phylogeographic structure was evident across small spatial scales, and a significant isolation-by-distance effect was observed. Genetic disjunctions in this region appear to correspond to the presence of long beaches. In contrast to the genetic structure found among central Chilean populations, samples from the southern Chilean Patagonian region (49° - 56°S were genetically homogeneous and identical to a haplotype recently found throughout the subantarctic region. Conclusions Southern (Patagonian Chile has been recolonised by D. antarctica relatively recently, probably since the LGM. The inferred trans

  12. Summer freezing resistance decreased in high-elevation plants exposed to experimental warming in the central Chilean Andes.

    Science.gov (United States)

    Sierra-Almeida, Angela; Cavieres, Lohengrin A

    2010-05-01

    Alpine habitats have been proposed as particularly sensitive to climate change. Shorter snow cover could expose high-elevation plants to very low temperatures, increasing their risk of suffering damage by freezing, hence decreasing their population viability. In addition, a longer and warmer growing season could affect the hardening process on these species. Thus, understanding the ability of these species to withstand freezing events under warmer conditions is essential for predicting how alpine species may respond to future climate changes. Here we assessed the freezing resistance of 11 species from the central Chilean Andes by determining their low temperature damage (LT(50)) and freezing point (FP) after experimental warming in the field. Plants were exposed during two growing seasons to a passive increase in the air temperature using open top chambers (OTCs). OTCs increased by ca. 3 K the mean air and soil daytime temperatures, but had smaller effects on freezing temperatures. Leaf temperature of the different species was on average 5.5 K warmer inside OTCs at midday. While LT(50) of control plants ranged from -9.9 to -22.4, that of warmed plants ranged from -7.4 to -17.3 degrees C. Overall, high-Andean species growing inside OTCs increased their LT(50) ca. 4 K, indicating that warming decreased their ability to survive severe freezing events. Moreover, plants inside OTCs increased the FP ca. 2 K in some studied species, indicating that warming altered processes of ice crystal formation. Resistance of very low temperatures is a key feature of high-elevation species; our results suggest that current climate warming trends will seriously threaten the survival of high-elevation plants by decreasing their ability to withstand severe freezing events. PMID:20237942

  13. Variabilidad Espacial de la Mineralización de Nitrógeno en un Suelo Volcánico de la Provincia de Ñuble, VIII Región, Chile Spatial Variability of Nitrogen Mineralization in a Volcanic Soil of Ñuble Province, VIII Region, Chile

    Directory of Open Access Journals (Sweden)

    Rodrigo Ortega B.

    2005-06-01

    Full Text Available El objetivo de este trabajo fue evaluar la variabilidad espacial de la mineralización de N en un suelo volcánico, correspondiente a una mezcla de las series Bulnes y Arrayán (Typic Distrandept de la provincia de Ñuble, Chile, para determinar el potencial del manejo sitio-específico de N, desde el punto de vista del suministro de N del suelo. Muestras de suelo intactas, georeferenciadas con un receptor de sistemas de posición global (GPS con señal diferencial (DGPS, contenidas en tubos de polivinilclorado (PVC (5 cm diámetro por 12 cm largo, con bolsas de resinas de intercambio iónico en su porción inferior, fueron incubadas in situ. Las cantidades de N-NO3 y N-NH4 extraídas desde el suelo fueron adicionadas al N-inorgánico extraído desde las resinas para determinar el N mineralizado durante los períodos de incubación. Para determinar N-NO3 se empleó el método de Self y Rodríguez (1998 modificado. A través del uso de herramientas geoestadísticas fue posible mapear adecuadamen te la variabilidad espacial del N mineralizado en los dos períodos de evaluación, así como en el intervalo total del estudio. Futuros estudios de mineralización de N in situ, en suelos similares, debieran considerar intensidades de 5 a 35 puntos ha-1, para asegurar dependencia espacial.The objective of this study was to characterize the spatial variability of N mineralization in a volcanic soil, corresponding to a mix of the Bulnes and Arrayan series (Typic Distrandept of Ñuble Province, Chile, to determine the potential of site-specific N management from the soil N-supply standpoint. Intact soil samples, georeferenced with a differential global position system (DGPS contained in PVC tubes (5 cm diameter by 12 cm length, with bags containing ion exchange resins were incubated in situ. The amounts of NO3-N plus NH4-N extracted from the soil were added to those extracted from the resin bags to determine N mineralized during the incubation periods. To

  14. 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

  15. 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.

  16. 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

  17. 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...

  18. The intensities and magnitudes of volcanic eruptions

    Science.gov (United States)

    Sigurdsson, H.

    1991-01-01

    Ever since 1935, when C.F Richter devised the earthquake magnitude scale that bears his name, seismologists have been able to view energy release from earthquakes in a systematic and quantitative manner. The benefits have been obvious in terms of assessing seismic gaps and the spatial and temporal trends of earthquake energy release. A similar quantitative treatment of volcanic activity is of course equally desirable, both for gaining a further understanding of the physical principles of volcanic eruptions and for volcanic-hazard assessment. A systematic volcanologic data base would be of great value in evaluating such features as volcanic gaps, and regional and temporal trends in energy release.  

  19. 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...

  20. 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…

  1. 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.

  2. 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

  3. Sub-glacial volcanic eruptions

    Science.gov (United States)

    White, Donald Edward

    1956-01-01

    The literature on sub-glacial volcanic eruptions and the related flood phenomena has been reviewed as a minor part of the larger problem of convective and conductive heat transfer from intrusive magma. (See Lovering, 1955, for a review of the extensive literature on this subject.) This summary of data on sub-glacial eruptions is part of a program that the U.S. Geological Survey is conducting in connection with its Investigations of Geologic Processes project on behalf of the Division of Research, U.S. Atomic Energy Commission.

  4. 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.

  5. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    Delmelle, Pierre; Delfosse, Thomas; Delvaux, Bruno

    2003-12-01

    The continuous emissions of SO{sub 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{sub 4}F- and 0.016 M KH{sub 2}PO{sub 4}-extractable sulfate (NH{sub 4}F-S and KH{sub 2}PO{sub 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{sub 4}F extracted systematically more (up to 40 times) sulfate than KH{sub 2}PO{sub 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 {approx}34 to 95% and {approx}65 to 98%, respectively. The distribution of KH{sub 2}PO{sub 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

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

    International Nuclear Information System (INIS)

    The continuous emissions of SO2, 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 NH4F- and 0.016 M KH2PO4-extractable sulfate (NH4F-S and KH2PO4-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, NH4F extracted systematically more (up to 40 times) sulfate than KH2PO4. 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 ∼34 to 95% and ∼65 to 98%, respectively. The distribution of KH2PO4-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 of fluoride over sulfate and chloride, and of

  8. 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.

  9. 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

  10. Electrostatic phenomena in volcanic eruptions

    International Nuclear Information System (INIS)

    Electrostatic phenomena have long been associated with the explosive eruption of volcanoes. Lightning generated in volcanic plumes is a spectacular atmospheric electrical event that requires development of large potential gradients over distances of up to kilometres. This process begins as hydrated liquid rock (magma) ascends towards Earth's surface. Pressure reduction causes water supersaturation in the magma and the development of bubbles of supercritical water, where deeper than c. 1000 m, and water vapour at shallower depths that drives flow expansion. The generation of high strain rates in the expanding bubbly magma can cause it to fracture in a brittle manner, as deformation relaxation timescales are exceeded. The brittle fracture provides the initial charge separation mechanism, known as fractoemission. The resulting mixture of charged silicate particles and ions evolves over time, generating macro-scale potential gradients in the atmosphere and driving processes such as particle aggregation. For the silicate particles, aggregation driven by electrostatic effects is most significant for particles smaller than c. 100 μm. Aggregation acts to change the effective aerodynamic behaviour of silicate particles, thus altering the sedimentation rates of particles from volcanic plumes from the atmosphere. The presence of liquid phases also promotes aggregation processes and lightning.

  11. Volcanic eruptions; energy and size

    Science.gov (United States)

    de la Cruz-Reyna, S.

    1991-01-01

    The Earth is a dynamic planet. Many different processes are continuously developing, creating a delicate balance between the energy stored and generated in its interior and the heat lost into space. The heat in continuously transferred through complex self-regulating convection mechanisms on a planetary scale. The distribution of terrestrial heat flow reveals some of the fine structure of the energy transport mechanisms in the outer layers of the Earth. Of these mechanisms in the outer layers of the Earth. Of these mechanisms, volcanism is indeed the most remarkable, for it allows energy to be transported in rapid bursts to the surface. In order to maintain the subtle balance of the terrestrial heat machine, one may expect that some law or principle restricts the ways in which these volcanic bursts affect the overall energy transfer of the Earth. For instance, we know that the geothermal flux of the planet amounts to 1028 erg/year. On the other hand, a single large event like the Lava Creek Tuff eruption that formed Yellowstone caldera over half a million years ago may release the same amount of energy in a very small area, over a short period of time. 

  12. Perchlorate levels in soil and waters from the Atacama Desert.

    Science.gov (United States)

    Calderón, R; Palma, P; Parker, D; Molina, M; Godoy, F A; Escudey, M

    2014-02-01

    Perchlorate is an anion that originates as a contaminant in ground and surface waters. The presence of perchlorate in soil and water samples from northern Chile (Atacama Desert) was investigated by ion chromatography-electrospray mass spectrometry. Results indicated that perchlorate was found in five of seven soils (cultivated and uncultivated) ranging from 290 ± 1 to 2,565 ± 2 μg/kg. The greatest concentration of perchlorate was detected in Humberstone soil (2,565 ± 2 μg/kg) associated with nitrate deposits. Perchlorate levels in Chilean soils are greater than those reported for uncultivated soils in the United States. Perchlorate was also found in superficial running water ranging from 744 ± 0.01 to 1,480 ± 0.02 μg/L. Perchlorate water concentration is 30-60 times greater than levels established by the United States Environmental Protection Agency (24.5 μg/L) for drinking. PMID:24165784

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

    Directory of Open Access Journals (Sweden)

    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.

  14. 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.

  15. Poetas mapuches en la literatura chilena Mapuche poets in Chilean literature

    Directory of Open Access Journals (Sweden)

    Iván Carrasco M

    2000-01-01

    Full Text Available En este trabajo se estudia el modo en que las tradiciones textuales etnoliterarias de los mapuches y literarias de los españoles, se han imbricado en la literatura chilena a través del tiempo, y los aportes que ha dejado la incorporación de poetas de cultura mapuche en la poesía chilena contemporánea. En particular, se establece que autores como Sebastián Queupul, Pedro Alonzo, Elicura Chihuailaf y Leonel Lienlaf han participado en la conformación de la poesía etnocultural, dentro de la cual han propuesto una visión intercultural que sobrepasa los límites de la etnoliteratura mapuche y la literatura chilena tradicional, y un conjunto de estrategias textuales compartidas con otros poetas (enunciación sincrética, intertextualidad transliteraria y codificación plural, en la cual han creado una variedad propia, el doble registro.This paper studies the way in which mapuche textual ethnoliterary traditions and Spanish literary traditions have mixed in the Chilean literature through time, and the contribution of Mapuche poets to contemporary Chilean poetry, particularly, authors such as Sebastián Queupul, Pedro Alonzo, Elicura Chihuailaf and Leonel Lienlaf, where they have created an intercultural view that goes beyond the limits of the mapuche ethnoliterature and Chilean traditional literature, together with a bunch of text strategies shared with others poets (syncretic enunciation, transliterary intertext and plural codification, where they have created their own variety, the double register.

  16. From Chaitén to the Chilean volcano monitoring network Jorge Munoz, Hugo Moreno, Servicio Nacional de Geología y Minería, Chile, jmunoz@sernageomin.cl

    Science.gov (United States)

    Muñoz, J.; Moreno, H.

    2010-12-01

    Chaitén volcano in southern Andes started a plinian to subplinian rhyolitic eruption on May 2008 following a long period of quiescence. A new dome complex grew up at high rates during 2008-2009 inside a 2 kilometers caldera like structure. Pyroclastic, laharic, block and ash flows and ash falls deposits have been affecting the surrounding populations, ground, vegetation, ocean and rivers, such as the laharic flows burying the currently evacuated Chaitén city. The geological, volcanologic and seismic knowledge produced during the eruption and the determination of evolutionary sceneries were properly transferred and consequently taken in account during complex decisions of authorities in charge of the emergency. As a result, no fatalities or major people injuries were produced during this rhyolitic eruption. Mainly as the consequence of the eruption of the Chaitén volcano but also due to the valuable technical advice during the crisis management, evacuation, hazards evolution, volcanic alerts and selection of sites for relocation of the Chaitén city provided by geologist and volcanologist from SERNAGEOMIN, the funding for the National Volcano Monitoring Network (RNVV) was approved during 2008 and it was integrated as a Bicentenary initiative. During the lapse of 5 year, RNVV need to create professional capacity and working teams, improve the current volcano observatory at Temuco and conform three new observatories at Coihaique, Talca and Antofagasta cities to implement volcano monitoring networks at the 43 hazardous volcanoes along the Chilean Andes. Monitoring net is currently conformed by seismic stations in 10 volcanoes or volcanic groups (San Pedro-San Pablo in Central Volcanic Andes and Llaima, Villlarrica, Mocho-Choshuenco, Carrán-Los Venados, Cordón Caulle, Osorno, Calbuco, Chaitén and Melimoyu in the southern volcanic Andes), in addition to gas measure and video camera stations in Llaima, Villarrica and Chaitén volcanoes. In addition, the geologic and

  17. Volatile profile characterisation of Chilean sparkling wines produced by traditional and Charmat methods via sequential stir bar sorptive extraction.

    Science.gov (United States)

    Ubeda, C; Callejón, R M; Troncoso, A M; Peña-Neira, A; Morales, M L

    2016-09-15

    The volatile compositions of Charmat and traditional Chilean sparkling wines were studied for the first time. For this purpose, EG-Silicone and PDMS polymeric phases were compared and, afterwards, the most adequate was selected. The best extraction method turned out to be a sequential extraction in the headspace and by immersion using two PDMS twisters. A total of 130 compounds were determined. In traditional Chilean sparkling wines, ethyl esters were significantly higher, while acetic esters and ketones were predominant in the Charmat wines. PCA and LDA confirmed the differences in the volatile profiles between the production methods (traditional vs. Charmat). PMID:27080904

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  20. 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.

  1. 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.

  2. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  4. Anaerobic oxidation of methane and sulfate reduction along the Chilean continental margin

    DEFF Research Database (Denmark)

    Treude, T.; Niggemann, J.; Kallmeyer, J.;

    2005-01-01

    Anaerobic oxidation of methane (AOM) and sulfate reduction (SR) were investigated in sediments of the Chilean upwelling region at three stations between 800 and 3000 In water depth. Major goals of this study were to quantify and evaluate rates of AOM and SR in a coastal marine upwelling system with...... peaks of 2 to 51 nmol cm(-3) d(-1), with highest rates at the shallowest station (800 m). The methane turnover was higher than in other diffusive systems of similar ocean depth. This higher turnover was most likely due to elevated organic matter input in this upwelling region offering significant...

  5. 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...

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

    Directory of Open Access Journals (Sweden)

    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

  7. 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...

  8. The Impact of a Carbon Tax on the Chilean Electricity Generation Sector

    OpenAIRE

    Carlos Benavides; Luis Gonzales; Manuel Diaz; Rodrigo Fuentes; Gonzalo García; Rodrigo Palma-Behnke; Catalina Ravizza

    2015-01-01

    This paper aims to analyse the economy-wide implications of a carbon tax applied on the Chilean electricity generation sector. In order to analyse the macroeconomic impacts, both an energy sectorial model and a Dynamic Stochastic General Equilibrium model have been used. During the year 2014 a carbon tax of 5 US$/tCO2e was approved in Chile. This tax and its increases (10, 20, 30, 40 and 50 US$/tCO2e) are evaluated in this article. The results show that the effectiveness of this policy depend...

  9. 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

  10. 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.

  11. 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

  12. Io Eclipse/Volcanic Eruption

    Science.gov (United States)

    1997-01-01

    This image was acquired while Io was in eclipse (in Jupiter's shadow) during Galileo's eighth orbit, and reveals several dynamic processes. The most intense features are red, while glows of lesser intensity are yellow or green, and very faint glows appear blue in this color-coded image. The small red or yellow spots mark the sites of high-temperature magma erupting onto the surface in lava flows or lava lakes.This image reveals a field of bright spots near Io's sub-Jupiter point (right-hand side of image). The sub-Jupiter hemisphere always faces Jupiter just as the Moon's nearside always faces Earth. There are extended diffuse glows on the equatorial limbs or edges of the planet (right and left sides). The glow on the left is over the active volcanic plume Prometheus, but whereas Prometheus appears to be 75 kilometers (46.6 miles) high in reflected light, here the diffuse glow extends about 800 kilometers (497 miles) from Io's limb. This extended glow indicates that gas or small particles reach much greater heights than the dense inner plume. The diffuse glow on the right side reaches a height of 400 kilometers (249 miles), and includes a prominence with a plume-like shape. However, no volcanic plume has been seen at this location in reflected light. This type of observation is revealing the relationships between Io's volcanism, atmosphere and exosphere.Taken on May 6, 1997, north is toward the top. The image was taken with the clear filter of the solid state imaging (CCD) system on NASA's Galileo spacecraft at a range of 1.8 million kilometers (1.1 million miles).The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is an operating division of California Institute of Technology (Caltech).This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational

  13. 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

    Directory of Open Access Journals (Sweden)

    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

  14. Climatic Impact of Volcanic Eruptions

    Directory of Open Access Journals (Sweden)

    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.

  15. 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.

  16. 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

  17. 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)).

  18. Analysis of pavement serviceability for the Aashto Design Method: The Chilean Case

    International Nuclear Information System (INIS)

    Serviceability is an indicator that represents the level of service a pavement provides to the users. This subjective opinion is closely related to objective aspects, which can be measured on the pavement's surface. This research aims specifically at relating serviceability results obtained by a 9-member evaluation panel, representing general public as closely as possible to parameters (particularly of roughness) measured within instruments on 30, 25 and 11 road sections of asphalt concrete, Portland cement concrete and asphalt overlay respectively. Results show that prediction of serviceability is quite accurate based on roughness evaluation, while also revealing that, by comparison to studies in more developed countries, Chileans are seemingly more tolerant, in that they assign a somewhat high rating to ride quality. Furthermore, visible distress does not have a significant influence on serviceability values for Chilean users. A ratio between International Roughness Index (IRI) and Serviceability, as defined by AASHTO, was developed and may be used in this design method. Results for the final pavement condition of urban pavements were obtained (IRI-asphalt final=5.9, IRI-concrete final=8.1). (author)

  19. 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.

  20. 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.

  1. 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.

  2. 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

  3. [Which are the causes of death among Chileans today?. Long-term perspectives].

    Science.gov (United States)

    Solimano C, Giorgio; Mazzei P, Marinella

    2007-07-01

    During the last decades, Chile experienced substantial socioeconomic, epidemiological and demographic changes. These resulted, among other consequences, in a deceleration of population growth, a notorious decrease in fertility rates, and one of the most rapid and deepest drop in general and infant mortality rates in the Latin American region. These changes resulted in a sustained increase of life expectancy and a substantial ageing of the Chilean population. This process is also changing the disease burden of the population. Infectious and perinatal diseases lost relevance as major causes of mortality, and have been replaced by chronic non transmissible diseases, specifically cardiovascular conditions and cancer, that are becoming the main causes of death. High blood pressure, cardiovascular risk, hypercholesterolemia, diabetes, overweight and obesity, smoking, sedentary lifestyle and depression will have a great impact on health conditions during the XXI century. These factors and a persistent social inequity will hinder the efforts to reduce the impact and consequences of chronic non transmissible, diseases in the Chilean population. PMID:17914552

  4. 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.

  5. Accuracy of Body Mass Index Cutoffs for Classifying Obesity in Chilean Children and Adolescents

    Science.gov (United States)

    Gómez-Campos, Rossana; David Langer, Raquel; de Fátima Guimarães, Roseane; Contiero San Martini, Mariana; Cossio-Bolaños, Marco; de Arruda, Miguel; Guerra-Júnior, Gil; Moreira Gonçalves, Ezequiel

    2016-01-01

    Objective: To determine the accuracy of two international Body Mass Index (BMI) cut-offs for classifying obesity compared to the percentage of fat mass (%FM) assessed by Dual-Energy X-ray Absorptiometry (DXA) in a Chilean sample of children and adolescents; Material and Methods: The subjects studied included 280 children and adolescents (125 girls and 155 boys) aged 8 to 17 years. Weight and height were measured. The BMI was calculated. Two international references (IOFT and WHO) were used as cut-off points. The %FM was assessed by DXA. The receiver operating characteristic (ROC) curve was used to assess the performance of BMI in detecting obesity on the basis of %FM; Results: A high correlation was observed between the %FM measured by the DXA and the Z-scores of IOTF and WHO scores in the Chilean adolescents separated by sex (r = 0.78–0.80). Differences occurred in both references (IOFT and WHO) in relation to the criteria (p < 0.001). Both references demonstrated a good ability to predict sensitivity (between 84% and 93%) and specificity (between 83% and 88%) in both sexes of children and adolescents; Conclusions: A high correlation was observed between the Z-score of the BMI with the percentage of fat determined by the DXA. Despite this, the classifications using the different BMI cut-off points showed discrepancies. This suggests that the cut-off points selected to predict obesity in this sample should be viewed with caution. PMID:27164119

  6. 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.

  7. How depositional conditions control input, composition, and degradation of organic matter in sediments from the Chilean coastal upwelling region

    DEFF Research Database (Denmark)

    Niggemann, Jutta; Ferdelman, Timothy G.; Lomstein, Bente Aagaard;

    2007-01-01

    Chilean coastal upwelling system and have an extended oxygen minimum zone in the water column. However, the northern site (23°S) borders the Atacama Desert, while the southern site (36°S) has a humid hinterland. Eight surface sediment cores (up to 30 cm long) from water depths of 126‑1350 m were...

  8. Filamentous bacteria inhabiting the sheaths of marine Thioploca spp. on the Chilean continental shelf

    DEFF Research Database (Denmark)

    Teske, Andreas; Jørgensen, Bo Barker; Gallardo, Victor A.

    2009-01-01

    A new component of the benthic Thioploca mat microbial ecosystem on the Chilean continental shelf was detected by epifluorescence microscopy: filamentous, bacterial endobionts of 4-5-μm filament diameter and length sometimes exceeding 1 mm. These filaments were identified as growing within...

  9. 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

  10. 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…

  11. 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

  12. 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.

  13. Volcanic caves of East Africa - an overview

    Directory of Open Access Journals (Sweden)

    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.

  14. 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

  15. Co-evolution of volcanic catchments in Japan

    Science.gov (United States)

    Yoshida, T.; Troch, P. A.

    2015-09-01

    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 0.225 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 catchments further evolve

  16. 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.

  17. 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...

  18. ASH REDISTRIBUTION FOLLOWING A POTENTIAL VOLCANIC ERUPTION AT YUCCA MOUNTAIN

    International Nuclear Information System (INIS)

    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 GIS 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 the redistribution

  19. 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

  20. 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...

  1. Volcanic eruptions are cooling the earth

    International Nuclear Information System (INIS)

    The article discusses how volcanic eruptions may influence the climate. The environmental impacts both on the earth surface and the atmosphere are surveyed. Some major eruptions in modern times are mentioned

  2. 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...

  3. 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...

  4. Volcanism and associated hazards: the Andean perspective

    Directory of Open Access Journals (Sweden)

    R. I. Tilling

    2009-12-01

    Full Text Available Andean volcanism occurs within the Andean Volcanic Arc (AVA, which is the product of subduction of the Nazca Plate and Antarctica Plates beneath the South America Plate. The AVA is Earth's longest but discontinuous continental-margin volcanic arc, which consists of four distinct segments: Northern Volcanic Zone, Central Volcanic Zone, Southern Volcanic Zone, and Austral Volcanic Zone. These segments are separated by volcanically inactive gaps that are inferred to indicate regions where the dips of the subducting plates are too shallow to favor the magma generation needed to sustain volcanism. The Andes host more volcanoes that have been active during the Holocene (past 10 000 years than any other volcanic region in the world, as well as giant caldera systems that have produced 6 of the 47 largest explosive eruptions (so-called "super eruptions" recognized worldwide that have occurred from the Ordovician to the Pleistocene.

    The Andean region's most powerful historical explosive eruption occurred in 1600 at Huaynaputina Volcano (Peru. The impacts of this event, whose eruptive volume exceeded 11 km3, were widespread, with distal ashfall reported at distances >1000 km away. Despite the huge size of the Huaynaputina eruption, human fatalities from hazardous processes (pyroclastic flows, ashfalls, volcanogenic earthquakes, and lahars were comparatively small owing to the low population density at the time. In contrast, lahars generated by a much smaller eruption (<0.05 km3 in 1985 of Nevado del Ruiz (Colombia killed about 25 000 people – the worst volcanic disaster in the Andean region as well as the second worst in the world in the 20th century. The Ruiz tragedy has been attributed largely to ineffective communications of hazards information and indecisiveness by government officials, rather than any major deficiencies in scientific data. Ruiz's disastrous outcome, however, together with responses to subsequent

  5. Unique pioneer microbial communities exposed to volcanic sulfur dioxide.

    Science.gov (United States)

    Fujimura, Reiko; Kim, Seok-Won; Sato, Yoshinori; Oshima, Kenshiro; Hattori, Masahira; Kamijo, Takashi; Ohta, Hiroyuki

    2016-01-01

    Newly exposed volcanic substrates contain negligible amounts of organic materials. Heterotrophic organisms in newly formed ecosystems require bioavailable carbon and nitrogen that are provided from CO2 and N2 fixation by pioneer microbes. However, the knowledge of initial ecosystem developmental mechanisms, especially the association between microbial succession and environmental change, is still limited. This study reports the unique process of microbial succession in fresh basaltic ash, which was affected by long-term exposure to volcanic sulfur dioxide (SO2). Here we compared the microbial ecosystems among deposits affected by SO2 exposure at different levels. The results of metagenomic analysis suggested the importance of autotrophic iron-oxidizing bacteria, particularly those involved in CO2 and N2 fixation, in the heavily SO2 affected site. Changes in the chemical properties of the deposits after the decline of the SO2 impact led to an apparent decrease in the iron-oxidizer abundance and a possible shift in the microbial community structure. Furthermore, the community structure of the deposits that had experienced lower SO2 gas levels showed higher similarity with that of the control forest soil. Our results implied that the effect of SO2 exposure exerted a selective pressure on the pioneer community structure by changing the surrounding environment of the microbes. PMID:26791101

  6. Unique pioneer microbial communities exposed to volcanic sulfur dioxide

    Science.gov (United States)

    Fujimura, Reiko; Kim, Seok-Won; Sato, Yoshinori; Oshima, Kenshiro; Hattori, Masahira; Kamijo, Takashi; Ohta, Hiroyuki

    2016-01-01

    Newly exposed volcanic substrates contain negligible amounts of organic materials. Heterotrophic organisms in newly formed ecosystems require bioavailable carbon and nitrogen that are provided from CO2 and N2 fixation by pioneer microbes. However, the knowledge of initial ecosystem developmental mechanisms, especially the association between microbial succession and environmental change, is still limited. This study reports the unique process of microbial succession in fresh basaltic ash, which was affected by long-term exposure to volcanic sulfur dioxide (SO2). Here we compared the microbial ecosystems among deposits affected by SO2 exposure at different levels. The results of metagenomic analysis suggested the importance of autotrophic iron-oxidizing bacteria, particularly those involved in CO2 and N2 fixation, in the heavily SO2 affected site. Changes in the chemical properties of the deposits after the decline of the SO2 impact led to an apparent decrease in the iron-oxidizer abundance and a possible shift in the microbial community structure. Furthermore, the community structure of the deposits that had experienced lower SO2 gas levels showed higher similarity with that of the control forest soil. Our results implied that the effect of SO2 exposure exerted a selective pressure on the pioneer community structure by changing the surrounding environment of the microbes.

  7. About the Mechanism of Volcanic Eruptions

    CERN Document Server

    Nechayev, Andrei

    2012-01-01

    A new approach to the volcanic eruption theory is proposed. It is based on a simple physical mechanism of the imbalance in the system "magma-crust-fluid". This mechanism helps to explain from unified positions the different types of volcanic eruptions. A criterion of imbalance and magma eruption is derived. Stratovolcano and caldera formation is analyzed. High explosive eruptions of the silicic magma is discussed

  8. Toward Forecasting Volcanic Eruptions using Seismic Noise

    OpenAIRE

    Brenguier, Florent; Shapiro, Nikolai M.; 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. The...

  9. 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...

  10. 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.

  11. 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...

  12. 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.

  13. Fatal Envenomation of a Chilean Flamingo (Phoenicopterus chilensis) From Eastern Yellow Jacket Wasps (Vespula maculifrons).

    Science.gov (United States)

    Suedmeyer, Wm Kirk; Trupkiewicz, John G

    2014-12-01

    A 37-year-old, female Chilean flamingo (Phoenicopterus chilensis) presented with severe facial angioedema, bilateral corneal and palpebral edema, nictitating membrane paralysis, bradycardia, bradypnea, hypothermia, and numerous stingers and remnants of eastern yellow jacket wasps (Vespula maculifrons) attached to the feathers of the head, palpebrae, and conjunctiva. Evaluation of 2 complete blood cell counts and results of plasma chemical analysis and serum protein electrophoresis revealed severe increases in creatinine phosphokinase and aspartate aminotransferase activity, electrolyte disturbances, and moderate increases in levels of α1, α2, β1, and γ immunoglobulins when compared with reference interval values and conspecifics. Despite intensive treatment, the bird died 19 hours after presentation. Results of histologic evaluation of tissues were compatible with envenomation. Response to envenomation in avian species is not documented but should be considered in birds presenting with angioedema. PMID:25843472

  14. Factors affecting aggression in a captive flock of Chilean flamingos (Phoenicopterus chilensis).

    Science.gov (United States)

    Perdue, Bonnie M; Gaalema, Diann E; Martin, Allison L; Dampier, Stephanie M; Maple, Terry L

    2011-01-01

    The influence of pair bond status, age and sex on aggression rates in a flock of 84 captive Chilean flamingos at Zoo Atlanta was examined. Analysis showed no difference between aggression rates of male and female flamingos, but adult flamingos had higher rates of aggression than juveniles. There were also significant differences in aggression depending on pair bond status (single, same-sex pair, male-female pair or group). Bonded birds were significantly more aggressive than single birds, which is consistent with the concept that unpaired birds are not breeding and do not need to protect pair bonds or eggs. Birds in typical pair bonds (male-female) and atypical pair bonds (same-sex pairs or groups) exhibited similar rates of aggression. These results contribute to the existing body of research on aggression in captive flamingos. PMID:20186725

  15. 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.

  16. 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

  17. 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.

  18. Free Trade Agreements and Firm-Product Markups in Chilean Manufacturing

    DEFF Research Database (Denmark)

    Lamorgese, A.R.; Linarello, A.; Warzynski, Frederic Michel Patrick

    In this paper, we use detailed information about firms' product portfolio to study how trade liberalization affects prices, markups and productivity. We document these effects using firm product level data in Chilean manufacturing following two major trade agreements with the EU and the US. The...... dataset provides information about the value and quantity of each good produced by the firm, as well as the amount of exports. One additional and unique characteristic of our dataset is that it provides a firm-product level measure of the unit average cost. We use this information to compute a firm......-product level measure of the profit margin that a firm can generate. We find that new products start being sold on foreign markets as export tariff fall. Moreover, for those products, we observe a fall in both prices and unit average costs. Those effects are mainly driven by an increase in productivity at the...

  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. 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.

  1. 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.

  2. 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)

  3. Characterization of Baker Fjord region through its heavy metal content on sediments (Central Chilean Patagonia

    Directory of Open Access Journals (Sweden)

    Ramón Ahumada

    2015-07-01

    Full Text Available The spatial distribution of heavy metals content (Ba, Cd, Cu, Pb, Sr and Zn in sediments of the Baker Fjord and surrounding channels in the central region of the Chilean fjords (47°45'S, 48°15'S is analyzed. The aim of the study was characterized the patterns of abundance and distribution of these metals in surface sediments. The area corresponds to a poorly studied zone with low human activity. Distribution patterns would be influenced by rainfall conditions (local erosion, fluvial (continental sediments carried by rivers, glacier (glacier flour and estuarine circulation. Cluster analysis allows differentiation among the sampled sites and group with similar characteristics. Finally, the concentrations found were contrasted with average values of metamorphic rocks and show with some certainty that the values found for calendar for this area and the greatest concentrations are the result of natural enrichment.

  4. 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.

  5. 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...

  6. 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...

  7. Volcanism on differentiated asteroids (Invited)

    Science.gov (United States)

    Wilson, L.

    2013-12-01

    after passing through optically dense fire fountains. At low eruption rates and high volatile contents many clasts cooled to form spatter or cinder deposits, but at high eruption rates and low volatile contents most clasts landed hot and coalesced into lava ponds to feed lava flows. Lava flow thickness varies with surface slope, acceleration due to gravity, and lava yield strength induced by cooling. Low gravity on asteroids caused flows to be relatively thick which reduced the effects of cooling, and many flows probably attained lengths of tens of km and stopped as a result of cessation of magma supply from the reservoir rather than cooling. On most asteroids larger than 100 km radius experiencing more than ~30% mantle melting, the erupted volcanic deposits will have buried the original chondritic surface layers of the asteroid to such great depths that they were melted, or at least heavily thermally metamorphosed, leaving no present-day meteoritical evidence of their prior existence. Tidal stresses from close encounters between asteroids and proto-planets may have very briefly increased melting and melt migration speeds in asteroid interiors but only gross structural disruption would have greatly have changed volcanic histories.

  8. 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. PMID:27010259

  9. Molecular characterization and antibiotic resistance of Enterococcus species from gut microbiota of Chilean Altiplano camelids

    Directory of Open Access Journals (Sweden)

    Katheryne Guerrero-Olmos

    2014-10-01

    Full Text Available Background: Enterococcus is one of the major human pathogens able to acquire multiple antibiotic-resistant markers as well as virulence factors which also colonize remote ecosystems, including wild animals. In this work, we characterized the Enterococcus population colonizing the gut of Chilean Altiplano camelids without foreign human contact. Material and methods: Rectal swabs from 40 llamas and 10 alpacas were seeded in M-Enterococcus agar, and we selected a total of 57 isolates. Species identification was performed by biochemical classical tests, semi-automated WIDER system, mass spectrometry analysis by MALDI-TOF (matrix-assisted laser desorption/ionization with a time-of-flight mass spectrometer, and, finally, nucleotide sequence of internal fragments of the 16S rRNA, rpoB, pheS, and aac(6-I genes. Genetic diversity was measured by pulsed field gel electrophoresis (PFGE-SmaI, whereas the antibiotic susceptibility was determined by the WIDER system. Carriage of virulence factors was explored by polymerase chain reaction (PCR. Results: Our results demonstrated that the most prevalent specie was Enterococcus hirae (82%, followed by other non–Enterococcus faecalis and non–Enterococcus faecium species. Some discrepancies were detected among the identification methods used, and the most reliable were the rpoB, pheS, and aac(6-I nucleotide sequencing. Selected isolates exhibited susceptibility to almost all studied antibiotics, and virulence factors were not detected by PCR. Finally, some predominant clones were characterized by PFGE into a diverse genetic background. Conclusion: Enterococcus species from the Chilean camelids’ gut microbiota were different from those adapted to humans, and they remained free of antibiotic resistance mechanisms as well as virulence factors.

  10. The congressional Committee System of the Chilean Legislature, 1834-1924

    Directory of Open Access Journals (Sweden)

    Iván Mauricio Obando Camino

    2011-06-01

    Full Text Available This is a historical, institutional study about the congressional committee system of the Chilean legislature from 1834 through 1924. This study uses a longitudinal perspective to focus on committee origins, functions, processes, and authority. It shows that the Chilean legislature developed a committee system early by taking stock of previous, short-lived congressional experiences and trial-and-error. Congressional committees dealt with bill drafting, housekeeping matters, and bureaucratic oversight therein with varying results. Congressional leaders presided over the committee appointment process by relying on majority support and persuasion. The impact of institutional design on committee performance, notwithstanding, the evidence shows that committees performed as specialized, authoritative agencies even before the emergence of modern political parties in the late 1850s.Este es un estudio histórico-institucional acerca del sistema de comisiones parlamentarias del Congreso chileno desde 1834 a 1924. Usando una perspectiva longitudinal para centrarse en los orígenes, funciones, procesos y autoridad de dichas comisiones, este artículo muestra que el Congreso chileno desarrolló un sistema de comisiones tempranamente, a partir de experiencias previas y de experimentación. En este sistema las comisiones redactaban leyes, se encargaban de asuntos internos y fiscalizaban la burocracia con resultados variados. Los líderes del Congreso tenían a su cargo la conformación de la comisiones, para lo cual se apoyaban en la mayoría parlamentaria y la persuasión. A pesar del impacto del diseño institucional sobre el desempeño de las comisiones, la evidencia muestra que estas se desempeñaron como agencias especializadas y autoritativas aun antes del surgimiento de los partidos políticos modernos, a fines de la década de 1850.

  11. 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

  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. 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

  14. 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

  15. Soils - Soil Data Viewer

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — Soil Data Viewer is a tool built as an extension to ArcMap that allows a user to create soil-based thematic maps. The application can also be run independent of...

  16. 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

  17. 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

  18. 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

  19. Steep spatial gradients of volcanic and marine sulfur in Hawaiian rainfall and ecosystems

    International Nuclear Information System (INIS)

    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 (δ34S VCDT) of − 0.8‰. Bulk deposition on the island of Maui had a δ34S 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 δ34S 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 over ecosystem

  20. 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

  1. 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

  2. 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)

  3. 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.

  4. 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.

  5. 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.

  6. Active Volcanic Eruptions on Io

    Science.gov (United States)

    1996-01-01

    Six views of the volcanic plume named Prometheus, as seen against Io's disk and near the bright limb (edge) of the satellite by the SSI camera on the Galileo spacecraft during its second (G2) orbit of Jupiter. North is to the top of each frame. To the south-southeast of Prometheus is another bright spot that appears to be an active plume erupting from a feature named Culann Patera. Prometheus was active 17 years ago during both Voyager flybys, but no activity was detected by Voyager at Culann. Both of these plumes were seen to glow in the dark in an eclipse image acquired by the imaging camera during Galileo's first (G1) orbit, and hot spots at these locations were detected by Galileo's Near-Infrared Mapping Spectrometer.The plumes are thought to be driven by heating sulfur dioxide in Io's subsurface into an expanding fluid or 'geyser'. The long-lived nature of these eruptions requires that a substantial supply of sulfur dioxide must be available in Io's subsurface, similar to groundwater. Sulfur dioxide gas condenses into small particles of 'snow' in the expanding plume, and the small particles scatter light and appear bright at short wavelengths. The images shown here were acquired through the shortest-wavelength filter (violet) of the Galileo camera. Prometheus is about 300 km wide and 75 km high and Culann is about 150 km wide and less than 50 km high. The images were acquired on September 4, 1996 at a range of 2,000,000 km (20 km/pixel resolution). Prometheus is named after the Greek fire god and Culann is named after the Celtic smith god.The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is an operating division of California Institute of Technology (Caltech).This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can

  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 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

  9. Lycaenid caterpillars (Lepidoptera, Lycaenidae eating flowers of Dalea pennellii var. chilensis (Fabaceae in the northern Chilean Andes

    Directory of Open Access Journals (Sweden)

    Héctor A. Vargas

    2014-09-01

    Full Text Available Lycaenid caterpillars (Lepidoptera, Lycaenidae eating flowers of Dalea pennellii var. chilensis (Fabaceae in the northern Chilean Andes. The shrub Dalea pennellii var. chilensis (Fabaceae is reported for the first time as a host plant for three Neotropical Polyommatini (Lepidoptera, Lycaenidae, Polyommatinae: Hemiargus ramon (Dognin, 1887, Leptotes trigemmatus (Butler, 1881 and Nabokovia faga (Dognin, 1895, based on two collections performed in the western slopes of the northern Chilean Andes in two consecutive summers. The relative abundance was always above 90% for N. faga while it was always less than 5% for H. ramon and L. trigemmatus. Furthermore, N. faga was not found on inflorescences of other native Fabaceae examined in the study site. This pattern suggests a close relationship between N. faga and D. pennellii var. chilensis, at least at a local scale.

  10. 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

  11. Geochemistry of volcanic series of Aragats province

    International Nuclear Information System (INIS)

    In this contribution we discuss geochemical and isotope characteristics of volcanism of the Aragats volcanic province and possible petrogenetical models of magma generation in collision zone of Armenian highland. We talk about combination of some specific features of collision related volcanism such as dry and high temperature conditions of magma generation, that demonstrate some similarities to intraplate-like petrogenesis and presence of mantle source enriched by earlier subductions, indicative to island-arc type magma generation models. Based on comprehensive analysis of isotope and geochemical data and some published models of magma generation beneath Aragats we lead to a petrogenetic model of origin of Aragats system to be a result of magma mixture between mantle originated mafic magma with felsic, adakite-type magmas

  12. 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.

  13. 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.

  14. 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...

  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. Effect of the 2010 Chilean Earthquake on Posttraumatic Stress Reducing Sensitivity to Unmeasured Bias Through Study Design

    OpenAIRE

    Zubizarreta, José R.; Cerdá, Magdalena; Rosenbaum, Paul R.

    2013-01-01

    In 2010, a magnitude 8.8 earthquake hit Chile, devastating parts of the country. Having just completed its national socioeconomic survey, the Chilean government reinterviewed a subsample of respondents, creating unusual longitudinal data about the same persons before and after a major disaster. The follow-up evaluated posttraumatic stress symptoms (PTSS) using Davidson’s Trauma Scale. We use these data with two goals in mind. Most studies of PTSS after disasters rely on recall to characterize...

  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. 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.

  20. 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...