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Sample records for andes chile estimated

  1. Use of time series of optical and SAR images in the estimation of snow cover for the optimization of water use in the Andes of Argentina and Chile

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    Salinas de Salmuni, Graciela; Cabezas Cartes, Ricardo; Menicocci, Felix

    2014-05-01

    This paper describes the progress in the bilateral cooperation project between academic and water resources management institutions from the Andes region of Argentina and Chile. The study zone is located in fragile ecosystems and mountain areas of the Andes (limit zone between the Province of San Juan, Argentina, and the IV Region of Coquimbo, Chile), with arid climate, where snow precipitates in the headwaters of watershed feed the rivers of the region by melting, which are the only source of water for human use, productive and energetic activities, as well as the native flora and fauna. CONAE, the Argentine Space Agency, participates in the Project through the provision of satellite data to the users and by this it contributes to ensuring the continuity of the results of the project. Also, it provides training in digital image processing. The project also includes the participation of water resource management institutions like Secretaria de Recursos Hidricos of Argentina and the Centro de Información de Recursos Naturales de Chile (CIREN), and of academic institution like the University of San Juan (Argentina) and University of La Serena (Chile). These institutions benefit from the incorporation of new methodologies advanced digital image processing and training of staff (researcher, lecturers, PhD Students and technical). Objectives: 1-Improve water distribution incorporating space technology for application in the prediction models of the stream flow. 2- Conduct an inventory of glaciers as well as studies in selected watersheds in the Andean region, aiming to know the water resource, its availability and potential risks to communities in the region. 3. Contribute to vulnerability studies in biodiversity Andean watersheds. Results: For estimation Snow cover Area, the MODIS images are appropriate due their high temporal resolution and allows for monitoring large areas (greater than 10 km) The proposed methodology (Use of snow index, NSDI) is appropriate for

  2. Estimating glacier and snowmelt contributions to stream flow in a Central Andes catchment in Chile using natural tracers

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    M. Rodriguez

    2014-07-01

    Full Text Available This paper presents a methodology for hydrograph separation in high elevation watersheds, which aims at identifying individual flow sources such as snow- and ice melt, rainfall and soil water. Daily summer and bi-daily spring water samples from the outlet of the Juncal River were analyzed for all major ions as well as stable water isotopes, δ18O and δ2H. Additionally, various water sources such as rain, springs, snow- and glacial melt were sampled throughout the catchment. A principal component analysis (PCA was performed in order to reduce the dimensionality of the problem. Potential sources were identified in a two-component U space that explains 77% of variability. Hydrograph separation (HS was performed through three models: (i Isotopic model, (ii Mixing–PCA model, and (iii Informative–Bayesian model, with very similar results in each case. At the Juncal River outlet, summer flows were composed by at least 50% of water originating in highly glaciarized headwaters in 2011–2012 (a dry period in the Central Andes. Autumn and winter flows were highly influenced by soil water and affect total annual discharge. Before the high flow season, snow melt accounted for approximately 25% of streamflow, However during summer, when streamflow was highest, snowmelt contribution was minimal, while glacier melt and soil water were the most important sources.

  3. New estimated Holocene denudation rates for non-glaciated areas in the southernmost Patagonian Andes (53°S), Chile

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    Breuer, Sonja; Kilian, Rolf; Baeza, Oscar; Arz, Helge

    2010-05-01

    Cenozoic denudation rates are sparsely known for the southernmost Patagonian Andes. One of the scientific approaches is to calculate long-term denudation rates based on fission track analyses. Though, these average rates comprise a long period with distinct climate conditions and very different extend of glaciation. These integrated denudation rates include extensive surface areas with different morphological, glacial and vegetational properties. In contrast, our approach is restricted to relative short Holocene periods and small catchment areas, for which the denudation and its controlling surface characteristics could be defined more precisely. Thus a more precise evaluation of the influencing parameters like climate, morphology and vegetation cover was possible. We concentrated on three restricted and nearly closed areas of denudation and accumulation. In those catchments we determined the sediment masses of lakes, based on sediment drilling, echosounding and computer based interpolation of the siliciclastic sediment masses. These masses were transferred to the denudation areas which have been characterised and measured by remote sensing. The westernmost Tamar Lake is located on the Tamar Island in the western part of the Magellan Strait, where the annual precipitation is about 4,000 mm. The catchment area has a dense vegetation cover. The lake surrounding slopes reach an elevation of 400 m a.s.l and they are up to 60° steep. The calculated denudation rate for this catchment is about 2.56 mm/ka, which represents a minimum value, because the postglacial weathering horizon is only partly removed into the lake. The highest elevated lake Muy Profundo (500 m a.s.l.) possesses a denudation area with a nearly vegetation-free zone up to 750 m a.s.l. within the Patagonian Batholith. The catchment area of this lake is characterised by a roche moutonnée landform with steep slopes and active fracture zones. The precipitation varies between 5,000 and 8,000 mm/a. The

  4. Glacier contribution to streamflow in two headwaters of the Huasco River, Dry Andes of Chile

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    Gascoin, S.; C. Kinnard; R. Ponce; S. Lhermitte; MacDonell, S; A. Rabatel

    2010-01-01

    Quantitative assessment of glacier contribution to present-day streamflow is a prerequisite to the anticipation of climate change impact on water resources in the Dry Andes. In this paper we focus on two glaciated headwater catchments of the Huasco Basin (Chile, 29° S). The combination of glacier monitoring data for five glaciers (Toro 1, Toro 2, Esperanza, Guanaco, Estrecho and Ortigas) with five automatic streamflow records at sites with glacier coverage of 0.4 to 11% allows the estimation ...

  5. Evolution of Parinacota volcano, Central Andes, Northern Chile

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    Jorge E. Clavero R.

    2004-12-01

    Full Text Available Parinacota is an active composite stratovolcano located in the Central Andes of Northern Chile (18°S. During its earlier stage (Parinacota 1 unit, Late Pleistocene, 300-70? ka rhyolitic to andesitic magmas were erupted, forming a voluminous lava-dome complex with its associated pyroclastic fans (mainly block-and-ash flow deposits, essentially deposited towards the Upper Lauca basin (West. It later evolved to a steep-sided composite stratocone (Parinacota 2 unit, Late Pleistocene-Holocene, 70?-8 ka, mainly formed by andesitic lava flows and scoria tephra fallout deposits.Around 8 ka ago the ancestral Parinacota volcano, built during Parinacota 1 and 2, partially collapsed towards the west, in a single and catastrophic event generating the outstanding Parinacota Debris Avalanche deposit.Soon after the collapse a new stratocone started to build with the emission of andesitic lava flows and pyroclastic flows, and their associated fallout deposits (Parinacota 3 unit, Holocene, La evolución del volcán Parinacota, Andes Centrales, norte de Chile. El volcán Parinacota es un estratovolcán activo ubicado en los Andes Centrales del norte de Chile (18°S. Durante su primera etapa de evolución (Unidad Parinacota 1, Pleistoceno Superior, 300-70? ka emitió magmas de composición riolítica a andesítica, formando un voluminoso complejo de lavas-domo con abanicos piroclásticos asociados (esencialmente depósitos de bloques y ceniza, distribuidos principalmente hacia la parte superior de la cuenca del río Lauca (oeste. Posteriormente, evolucionó a un estratocono compuesto, de fuertes pendientes (Unidad Parinacota 2, Pleistoceno-Holoceno, 70?-8 ka, formado principalmente por lavas y depósitos de caída andesíticos. Aproximadamente hace 8 ka el volcán Parinacota ancestral, construido durante las unidades Parinacota 1 y 2, colapsó parcialmente hacia el oeste, en un evento único y catastrófico generando el Depósito de Avalancha de Parinacota. Poco

  6. Síndrome pulmonar por hantavirus Andes en Chile CARDIOPULMONARY SYNDROME DUE TO ANDES VIRUS IN CHILE

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    CONSTANZA CASTILLO H.

    2002-01-01

    Full Text Available Desde 1993 han ocurrido 204 casos de Síndrome Cardiopulmonar por Hantavirus (SCPH en Chile. Los brotes epidémicos comenzaron en el sur y avanzan hacia el norte del país. Los más afectados son varones jóvenes, obreros agrícolas o forestales. En Chile, el SCPH es causado por el virus Andes, cuyo reservorio es el Oligorizomys longicaudatus (ratón de cola larga, que se distribuye desde la III Región al sur. El cuadro clínico es similar al descrito en EE.UU., caracterizado por una fase prodrómica que simula un estado gripal o cuadro gastrointestinal febril y que agrava por la aparición de edema pulmonar agudo e inestabilidad hemodinámica (fase cardiopulmonar. Sin embargo, cursa con mayores alteraciones hemorragí-paras y compromiso renal. La mortalidad inicial fue sobre 50% y actualmente es de alrededor del 33,3%. La presente revisión incluye: historia de la enfermedad, reservorio, modos de transmisión, patogenia, cuadro clínico, diagnóstico, tratamiento y medidas de prevenciónSince 1993, 204 cases of Hantavirus cardiopulmonary syndrome (HCPS occurred in Chile. Epidemic began in the south and moved thereafter to the northern regions. The disease affected predominantly young males, who worked in agricultural labours or as timber workers. The HCPS in Chile is caused by the Andes virus. The reservoir is the wild rat Oligoryzomis longicaudatus distributed from the III to the XII Region. The clinical features are similar to those described for Sin Nombre Virus. The disease has a prodromal stage characterised by fever, muscular pain, with or without gastrointestinal manifestations, followed by the rapid onset of respiratory insufficiency and haemodynamic unstability. Andes virus courses more often with haemorrhagic disorders and overt renal failure, than Sin Nombre Virus. The initial mortality was over 50% and declined to 33,3% in the last year. History of hantavirus-diseases, reservoir, and mode of contagion, pathogenesis, clinical

  7. Revisiting mountain-building in the Andes of Central Chile: constraints from structural geology and thermochronology.

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    Riesner, M.; Lacassin, R.; Simoes, M.; Armijo, R.; Carrizo, D.

    2015-12-01

    The Andes, one of the most significant reliefs on Earth, is the case example of a subduction-type mountain belt. In central Chile and western Argentina, the particular east-vergent structure of the Aconcagua fold-and-thrust belt (AFTB) is found atop a huge basement high with elevations > 4000 m, the Frontal Cordillera. Classical conceptual models consider the Andes as an east-vergent orogen, opposite to the Nazca subduction, and describe the exhumation of the Frontal Cordillera as an eastward in-sequence event that occurred late in the andean deformation (by ~10My). An alternative model recently challenged this view by proposing that the Andes have mainly a primary westward vergence. Within this scheme, the exhumation of the Frontal Cordillera would have begun earlier, by ~25My, synchronous with formation of the AFTB on the western side of the basement high. Here we test these two models by revisiting structural cross-sections of the Andes at the latitude of Santiago de Chile and of the Aconcagua (~33°S). We provide thermochronological constraints on the timing of exhumation of the Frontal Cordillera by (U-Th)/He dating on apatites retrieved from paleozoic granitoids along a 2,3km high nearly vertical section in the core of the basement high. Preliminary results suggest that the Frontal Cordillera exhumation was not a late event and likely began around 25 Ma. Therefore it appears to be synchronous with deformation within the AFTB and the westernmost fold-and-thrust belt at this latitude. We discuss these results and their implications while building a crustal-scale cross section of the range at the latitude of Santiago de Chile.

  8. Miocene-Quaternary structural evolution of the Uyuni-Atacama region, Andes of Chile and Bolivia

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    Tibaldi, A.; Università degli Studi di Milano-Bicocca; Corazzato, C.; Università degli Studi di Milano-Bicocca; Rovida, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Milano-Pavia, Milano, Italia

    2008-01-01

    We describe the Miocene-Quaternary geological-structural evolution of the region between the Salar de Uyuni and de Atacama, Andes of Chile and Bolivia. We recognised four main tectonic events based on fold geometry, fault kinematics and stratigraphic data. The oldest event, of Miocene age, is characterized by folding and reverse faulting of the sedimentary successions with an E-W direction of shortening in the northern part of the studied area and a WNW-ESE shortening in the southern part. Th...

  9. Long-term denudation rates from the Central Andes (Chile) estimated from a digital elevation model using the black top hat function and inverse distance weighting : implications for the neogene climate of the Atacama Desert

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    Riquelme, R.; Darrozes, J; Maire, E.; Hérail, Gérard; J. C. Soula

    2008-01-01

    A methodology for determining long-term denudation rates from morphologic markers in a Digital Elevation Model (DEM) is checked by a comparative study of two drainage basins in the Precordillera of the Central Andes. In both cases the initial configuration of an incised pediment surface has been restored by using two different methods: the Black Top Hat (BTH) function and the Inverse Distance Weighting (IDW) interpolation. Where vertical incision and hillslope erosion are recorded, the 1DW ap...

  10. Classification of debris-covered glaciers and rock glaciers in the Andes of central Chile

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    Janke, Jason R.; Bellisario, Antonio C.; Ferrando, Francisco A.

    2015-07-01

    In the Dry Andes of Chile (17 to 35° S), debris-covered glaciers and rock glaciers are differentiated from true glaciers based on the percentage of surface debris cover, thickness of surface debris, and ice content. Internal ice is preserved by an insulating cover of thick debris, which acts as a storage reservoir to release water during the summer and early fall. These landforms are more numerous than glaciers in the central Andes; however, the existing legislation only recognizes uncovered or semicovered glaciers as a water resource. Glaciers, debris-covered glaciers, and rock glaciers are being altered or removed by mining operations to extract valuable minerals from the mountains. In addition, agricultural expansion and population growth in this region have placed additional demands on water resources. In a warmer climate, as glaciers recede and seasonal water availability becomes condensed over the course of a snowmelt season, rock glaciers and debris-covered glaciers contribute a larger component of base flow to rivers and streams. As a result, identifying and locating these features to implement sustainable regional planning for water resources is important. The objective of this study is to develop a classification system to identify debris-covered glaciers and rock glaciers based on the interpretation of satellite imagery and aerial photographs. The classification system is linked to field observations and measurements of ice content. Debris-covered glaciers have three subclasses: surface coverage of semi (class 1) and fully covered (class 2) glaciers differentiates the first two forms, whereas debris thickness is critical for class 3 when glaciers become buried with more than 3 m of surface debris. Based on field observations, the amount of ice decreases from more than 85%, to 65-85%, to 45-65% for semi, fully, and buried debris-covered glaciers, respectively. Rock glaciers are characterized by three stages. Class 4 rock glaciers have pronounced

  11. Meteorological drivers of ablation processes on a cold glacier in the semiarid Andes of Chile

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    S. MacDonell

    2013-04-01

    Full Text Available Meteorological and surface change measurements collected during a 2.5 yr period are used to calculate surface mass and energy balances at 5324 m a.s.l. on Guanaco Glacier, a cold-based glacier in the semi-arid Andes of Chile. Meteorological conditions are marked by extremely low vapour pressures (annual mean of 1.1 hPa, strong winds (annual mean of 10 m s−1, high shortwave radiation receipt (mean annual 295 W m−2 and low precipitation rates (mean annual 45 mm w.e.. Net shortwave radiation provides the greatest source of energy to the glacier surface, and net longwave radiation dominates energy losses. The turbulent latent heat flux is always negative, which means that the surface is always losing mass via sublimation, which is the main form of ablation at the site. Sublimation rates are most strongly correlated with net shortwave radiation, incoming shortwave radiation, albedo and vapour pressure. Low glacier surface temperatures restrict melting for much of the period, however episodic melting occurs during the austral summer, when warm, humid, calm and high pressure conditions restrict sublimation and make more energy available for melting. Low accumulation (131 mm w.e. over the period and relatively high ablation (1435 mm w.e. means that mass change over the period was negative (−1304 mm w.e., which continued the negative trend recorded in the region over the last few decades.

  12. Parameterisation of incoming longwave radiation over glacier surfaces in the semiarid Andes of Chile

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    MacDonell, Shelley; Nicholson, Lindsey; Kinnard, Christophe

    2013-02-01

    A good understanding of radiation fluxes is important for calculating energy, and hence, mass exchange at glacier surfaces. This study evaluates incoming longwave radiation measured at two nearby glacier stations in the high Andes of the Norte Chico region of Chile. These data are the first published records of atmospheric longwave radiation measurements in this region. Nine previously published optimised parameterisations for clear sky emissivity all produced results with a root mean square error (RMSE) ~20 W m-2 and bias within ±5 W m-2, which is inline with findings from other regions. Six optimised parameterisations for incoming longwave in all sky conditions were trialled for application to this site, five of which performed comparably well with RMSE on daytime data <18 W m-2 and bias within ±6 W m-2 when applied to the optimisation site and RMSE <20 W m-2 and bias within ±10 W m-2 when applied to the validation site. The parameterisation proposed by Mölg et al. (J Glaciol 55:292-302, 2009) was selected for use in this region. Incorporating the proposed elevation modification into the equation reduced the bias in the modelled incoming longwave radiation for the validation site. It was found that applying the parameterisation optimised in the original work at Kilimanjaro produced good results at both the primary and validation site in this study, suggesting that this formulation may be robust for different high mountain regions.

  13. Constraints on sediment transfer from the Andes to the coast of northern Chile

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    Binnie, Steven; Liermann, Ariane; Dunai, Tibor; Dewald, Alfred; Heinze, Stefan

    2013-04-01

    While rates of denudation have been suggested as having the potential to link tectonic processes with climate in many settings, the roles that sediment transport must also play have been largely neglected. It is the transport, or not, of eroded material, not necessarily the rate at which that material is produced which is the critical factor in many models of tectonic-climatic interactions. The notable lack of sediment in sections of the Peru-Chile trench has been implicated as a key control of subduction zone processes and consequently Andean mountain building, but little empirical data on sediment transport in the region exists. Here, we present the initial results of a study aiming to constrain the westward transfer of sediment from the Andes Mountains to the Pacific Coast of northern Chile by using in situ-produced cosmogenic nuclides. Fluvial sediments were collected at the mouths of several large catchments between 19° S and 26° S, where they drain into the Pacific, and also from upstream locations within each catchment. Sample sites were selected in order to investigate the cosmogenic nuclide derived basin-averaged denudation rates of the western flank of the Andes, and to compare this with the cosmogenic nuclide concentrations of fluvial sediments further downstream where the catchments exit to the coast. A simplistic interpretation of the cosmogenic 10Be concentrations as denudation rates gives results varying between ~10 and 300 m/Myr. We would expect the most rapid erosion to occur on the steeper, wetter western Andean flank and for slower erosion to be recorded from the more gentle sloping, hyperarid/arid regions between the foothills of the Andes and the Pacific coast. This pattern is observed in some basins but in others the nuclide concentrations imply the opposite, with several-fold higher erosion rates measured for the large catchments sampled at the coast in comparison to their mountainous Andean headwaters. One explanation for this unusual

  14. Late Pleistocene glaciations of the arid subtropical Andes and new results from the Chajnantor Plateau, northern Chile

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    Ward, Dylan J.; Cesta, Jason M.; Galewsky, Joseph; Sagredo, Esteban

    2015-11-01

    The spatiotemporal pattern of glaciation along the Andes Mountains is an important proxy record reflecting the varying influence of global and regional circulation features on South American climate. However, the timing and extent of glaciation in key parts of the orogen, particularly the deglaciated arid Andes, are poorly constrained. We present new cosmogenic 10Be and 36Cl exposure ages for glacial features on and near the Chajnantor Plateau (23 °S). The new dates, although scattered due to cosmogenic inheritance, imply that the most recent extensive glacial occupation ended before or during the global Last Glacial Maximum (LGM). We discuss this new record in the context of published glacial chronologies from glacial features in Peru, Bolivia, and northern Chile rescaled using the latest cosmogenic 10Be production rate calibration for the tropical Andes. The results imply regionally synchronous moraine stabilization ca. 25-40 ka, 15-17 ka, and 12-14 ka, with the youngest of these moraines absent in records south of ˜20 °S, including in our new Chajnantor area chronology. This spatial pattern implicates easterly moisture in generating sufficient snowfall to glaciate the driest parts of the Andes, while allowing a role for westerly moisture, possibly modulated by the migration of the Southern Westerly Wind belt, in the regions near and south of the Atacama Desert.

  15. Miocene-Quaternary structural evolution of the Uyuni-Atacama region, Andes of Chile and Bolivia

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    Tibaldi, A.; Corazzato, C.; Rovida, A.

    2009-06-01

    We describe the Miocene-Quaternary geological-structural evolution of the region between the Salar de Uyuni and de Atacama, Andes of Chile and Bolivia. We recognized four main tectonic events based on fold geometry, fault kinematics and stratigraphic data. The oldest event, of Miocene age, is characterized by folding and reverse faulting of the sedimentary successions with an E-W direction of shortening in the northern part of the studied area and a WNW-ESE shortening in the southern part. The following two events, of Pliocene age, are characterized by lower shortening amounts; they occurred first by reverse faulting with a NW-SE-trending greatest principal stress ( σ1, computed with striated fault planes) and a vertical least principal stress ( σ3), followed by pervasive strike-slip faulting with the same NW-SE-trending σ1 and a horizontal NE-SW σ3. The fourth event, dating to the late Pliocene-Quaternary is characterized by normal faulting: the σ3 still trends NE-SW, whereas the intermediate principal stress σ2 exchanged with σ1. Volcanism accompanied both the contractional, transcurrent and extensional tectonic phases. The Mio-Pliocene compression appears directly linked to a rapid convergence and an apparently important coupling between the continental and oceanic plates. The E-W to WNW-ESE direction of shortening of the Miocene structures and the NW-SE σ1 of the Pliocene structures seem to be more linked to an intra-Andean re-orientation of structures following the WNW-directed absolute motion of the South-American Plate. The extensional deformations can be interpreted as related to gravity forces affecting the highest parts of the volcanic belt in a sort of asymmetrical (SW-ward) collapse of the belt.

  16. River runoff and regional climate of a small glaciated catchment area in the Andes in southernmost Patagonia, Chile

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    Schneider, C.; Moritz, M.; Kilian, R.

    2003-04-01

    The river runoff from a small partly glaciated catchment area in southernmost Patagonian Andes in Chile is measured to analyse the influence of regional precipitation and climate dependent glacier ablation on runoff. The first data from March to September 2002 were compared to climate data recorded at an automatic weather station in the area. The poster presents the first detailed hydrometeorological investigation from this part of the Andes. The investigation area is located at 53°S in southernmost South America exactly east of the main divide of the mountain range of the Andes at 72.5°W. The catchment area of about 15 km2 comprises parts of the Gran Campo Nevado Ice Cap reaching up to 1500 m asl, and the outlet glacier Glaciar Lengua which ends at a proglacial lake at 100 m asl. The Gran Campo Nevado Ice Cap is the major ice mass between the Southern Patagonian Ice field in the north and the Strait of Magallan to the South. Climate in the area is characterised by whole-year round cool and super-humid conditions with a mean annual air temperature of 5,6°C at sea level and an annual precipitation sum of approximately 7,000 mm. The Río Lengua itself meets approximately 3.5 km downstreams from the proglacial lake into the fjord system of Canal Garjado which is a branch of Seno Skyring. A continuous hourly record of water levels in the river was obtained from two digital water depth sensors. Runoff was calibrated against river level by measuring runoff at different times with the tracer method of salt dilution and with velocity measurements employing a hydrometric vane. Mean runoff was computed to about 3 m3/s with peak flows exceeding 10 m3/s. Ablation on the glacier was estimated using the degree-day method with a degree-day factor that has been calibrated previously using data from a temporal energy balance weather station on Glacíar Lengua. The correlation between runoff and air temperature and precipitation returned significant correlation coefficients of rt

  17. Reconstruction of cryospheric changes in the Maipo and Juncal river basins, central Andes of Chile: an integrative geomorphological approach

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    Nussbaumer, Samuel U.; García, Juan L.; Gómez, Gabriel; Vega, Rodrigo M.; Gärtner-Roer, Isabelle; Salzmann, Nadine

    2016-04-01

    Water in the central Andes (32-38° S), a semi-arid mountainous area with elevations over 6000 m asl., is of great importance and a critical resource especially in the dry summer months. Ice bodies, such as glaciers and rock glaciers (permafrost) in the high mountains, provide a substantial part of the fresh-water resources but also for intensive economical use for the lowlands including Santiago metropolitan region, Chile. However the evolution of these ice bodies since the last deglaciation (i.e., Holocene, last ˜12,000 years), and in particular during historical times, and their feedback with climate is fairly unknown. In view of projected climate change, this is striking because it is also unknown whether these natural resources could be used as sustainable fresh-water source in the future. Within the presented project, we develop and apply an integrative geomorphologic approach to study glaciers and their long-term evolution in the central Andes of Chile. Apart from glaciers (with variable debris-coverage), rock glaciers have evolved over time as striking geomorphological landforms in this area. We combine geomorphologic mapping using remote-sensing and in-situ data with an innovative surface exposure dating technique to determine the ages of distinct moraine ridges at three study sites in watersheds of the Santiago region: Juncal Norte, Loma Larga and Nieves Negras glaciers. First results of the project are presented, including a detailed geomorphological mapping and first analysis of the landform dynamics. At all three sites, we distinguished at least three moraine systems of a Holocene putative age. These prominent moraine belts show that glaciers were at least 5 km longer than at present. Deglaciation from these ice marginal positions was gradual and complex in response to the detrital cover on the glaciers. Differences in ice thickness of the main glaciers in the respective valleys amount to about 100 m. Due to the partial, extensive debris coverage, the

  18. Chile.

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    1988-09-01

    Chile is a long (2650 miles), narrow (250 miles at widest point) country sandwiched between the Andes mountains and the Pacific. The northern desert is rich in copper and nitrates; the temperate middle region is agricultural and supports the major cities, including Santiago, the capital, and the port of Valparaiso; and the southern region is a cold and damp area of forests, grasslands, lakes, and fjords. The country is divided into 12 administrative regions. Chile's population of 12.5 million are mainly of Spanish or Indian descent or mestizos. Literacy is 92.3%, and the national language is Spanish. Infant mortality is 18.1/1000, and life expectancy is 68.2 years. 82% of the people are urban, and most are Roman Catholics. Chile was settled by the Spanish in 1541 and attached to the Viceroyalty of Peru. Independence was won in 1818 under the leadership of Bernardo O'Higgins. In the 1880s Chile extended its sovereignty over the Strait of Magellan in the south and areas of southern Peru and Bolivia in the north. An officially parliamentary government, elected by universal suffrage, drifted into oligarchy and finally into a military dictatorship under Carlos Ibanez in 1924. Constitutional government was restored in 1932. The Christian Democratic government of Eduardo Frei (1964-70) inaugurated major reforms, including land redistribution, education, and far-reaching social and economic policies. A Marxist government under Salvador Allende lasted from 1970 to 1973 when the present military government of General Pinochet Ugarte took power, overthrew Allende, abolished the Congress, and banned political parties. It has moved the country in the direction of a free market economy but at the cost of systematic violations of human rights. A new constitution was promulgated in 1981, and congressional elections have been scheduled for October, 1989. A "National Accord for Transition to Full Democracy" was mediated by the Catholic Church in 1985. The social reforms of the

  19. Altitudinal vegetation belts in the high-Andes of central Chile (33°S Pisos altitudinales de vegetación en los Andes de Chile central (33°S

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    Lohengrin A. Cavieres

    2000-06-01

    Full Text Available The limits of alpine vegetation belts have been established mainly based on physiognomic criteria. However, a more objective approach for fixing limits of vegetation belts are methods based on species composition and relative abundance of each species. While these methods are more time consuming, they are more detailed and permit the detection of physical factors affecting the limits of vegetation belts. In this paper we: 1 describe the altitudinal changes of vegetation above timberline, 2 compare vegetation belts defined with physiognomy and two floristic methods (a qualitative one based on altitudinal changes in species composition, and a quantitative one based on changes in dominant species; and 3 detect some environmental factors responsible for the altitudinal distribution of alpine vegetation between 2100 and 3700 masl in the Andes of Santiago, central Chile (33°S. There was a complete agreement between the different methods in delimiting the subalpine belt. However, in the lower alpine belt (the cushion's belt floristic methods subdivided it in 2-3 sub-belts. In the floristic methods, elevations 3500-3700 that formed the higher alpine belt segregated in separate ways because they have no species in common. Physiognomic descriptions lose relevant information about species distribution, especially at higher elevations. Mean annual temperature and nitrogen content of soil are the main environmental factors affecting the altitudinal limits of vegetation belts in the central Chilean AndesLa delimitación de los pisos altitudinales de vegetación andina se ha basado principalmente en criterios fisionómicos. Sin embargo, un criterio más objetivo para la delimitación es usar métodos basados en la composición y abundancia relativa de las especies presentes. Mientras estos métodos requieren de un mayor esfuerzo de muestreo, son más detallados y permiten detectar factores físicos involucrados en la delimitación altitudinal de la vegetaci

  20. Pluri-decadal (1955–2014) evolution of glacier–rock glacier transitional landforms in the central Andes of Chile (30–33° S)

    OpenAIRE

    Monnier, S.; C. Kinnard

    2016-01-01

    This study deals with relationships between debris-covered glaciers and rock glaciers in the central Andes of Chile. Three glacier–rock glacier transitional landforms are investigated over the last decades in order to highlight and question the significance of their landscape evolution and dynamics. We use series of historical air photos and Geoeye satellite images together with common remote sensing operations including imagery orthorectification, digital elevation model generation, an...

  1. A study of the energy balance and melt regime on Juncal Norte Glacier, semi-arid Andes of central Chile, using melt models of different complexity

    OpenAIRE

    Pellicciotti, Francesca; Helbing, Jakob; Rivera, Andrés; Favier, Vincent; Corripio, Javier; Araos, José; Sicart, Jean-Emmanuel; Carenzo, Marco

    2008-01-01

    We use meteorological data from two automatic weather stations (AWS) on Juncal Norte Glacier, central Chile, to investigate the glacier-climate interaction and to test ablation models of different complexity. The semi-arid Central Andes are characterized by dry summers, with precipitation close to zero, low relative humidity and intense solar radiation. We show that katabatic forcing is dominant both on the glacier tongue and in the fore field, and that low humidity and absence of clouds caus...

  2. Tectonic styles and crustal shortening of the Central Andes "Pampean" flat-slab segment in northern Chile (27-29°S)

    Science.gov (United States)

    Martínez, Fernando; Arriagada, César; Peña, Matías; Deckart, Katja; Charrier, Reynaldo

    2016-01-01

    The Andean orogenic belt, located in the Central Andes "Pampean flat-slab" segment in northern Chile (27-29°S), is composed of two major tectonic regions: the Coastal Cordillera and the Frontal Cordillera. To understand their internal tectonic styles, history of growth and the shortening absorbed by the upper crustal structure of this segment, we combined regional geological mapping data, new ages obtained from radiometric U-Pb dating, and a semibalanced and restored cross-section 225.18 km in length. The results as shown in the previous Mesozoic extensional fault systems, established in northern Chile by the Gondwana breakup, have played a fundamental role in the orogenic buildup. The central structure is characterized by an asymmetric basin (Upper Cretaceous-Paleocene) confined by a doubly vergent fault system composed of inverted faults related to the edges of the Mesozoic Chañarcillo and Lautaro Basins. The U-Pb geochronological data obtained from synorogenic volcano-sedimentary deposits and the angular unconformities recorded between the Cenozoic geological units have revealed that the compressive deformation in this segment started at around ~ 80 Ma by tectonic inversion in the eastern Coastal Cordillera and western Frontal Cordillera, however, the presence of Paleocene and Miocene synorogenic successions at the footwall of the basement reverse faults of the Frontal Cordillera suggests a migration of Andean deformation from the west to the east during the Paleocene-Miocene by propagation of ramps involving inherited basement highs. The pre-compression restoration makes it possible to estimate 40.94 km of minimum shortening, concentrated by inversion anticlines and fault-controlled basement highs across the Frontal Cordillera.

  3. Photosynthetic performance of Colobanthus quitensis (Kunth Bartl. (Caryophyllaceae in a high-elevation site of the Andes of central Chile Desempeño fotosintético de Colobanthus quitensis (Kunth Bartl. (Caryophyllaceae en los Andes de Chile central

    Directory of Open Access Journals (Sweden)

    M. ANGÉLICA CASANOVA-KATNY

    2006-03-01

    Full Text Available Photosynthesis of Colobanthus quitensis and mesoclimatic conditions of air temperature and light intensity during the growing season were investigated at 2,650 m in the central Chilean Andes. On three typical days of the growing period (January, March and May, CO2 exchange and chlorophyll fluorescence were measured. In addition, a series of fluorescence response curves with increasing light intensity at different temperatures were performed to estimate the propensity of Andean C. quitensis populations to be photoinhibited. Net Photosynthesis (Pn was low (ca. 2.0 mmol CO2 m-2s-1 during the morning and noon in days with high photosynthetic active radiation (PAR, above 1,800 mmol photons m-2s-1. Pn increased in the afternoon (3.5-4.8 mmol CO2 m-2s-1 when PAR decreased to ca. 1,400 mmol photons m-2s-1 and leaf temperature were ca. 20 °C. Fv/Fm in the diurnal periods was between 0.7-0.75 without evidence of photoinhibition. Leaves at 15 and 22 °C exhibited a slow decrease of F PSII with the increase in actinic light intensity, although the fraction of reaction centers open (expressed by qP remained higher at 22 °C. NPQ was saturated at light intensities close to 500 mmol photons m-2s-1 in leaves at 22 °C and at higher intensities at 15 °C, suggesting that NPQ could be a mechanism of energy dissipation at high light intensity and high leaf temperature in the field. Our results indicated that C. quitensis is not photodamaged during the diurnal cycle and that the low Pn registered during some diurnal periods are likely to be related with photorespiration, which has been suggested as an efficient protective mechanism for photoinhibition in alpine plants. Our results are also compared with the photosynthetic performance of C. quitensis populations from the maritime AntarcticSe estudió la fotosíntesis de Colobanthus quitensis y las condiciones mesoclimáticas de temperatura del aire e intensidad lumínica a 2.650 m en los Andes de Chile central. Se

  4. Reconstructing glacier mass balances in the Central Andes of Chile and Argentina using local and regional hydro-climatic data

    Directory of Open Access Journals (Sweden)

    M. H. Masiokas

    2015-09-01

    Full Text Available Despite the great number and variety of glaciers in southern South America, in situ glacier mass balance records are extremely scarce and glacier–climate relationships are still poorly understood in this region. Here we use the longest (> 35 years and most complete in situ mass balance record, available for glaciar Echaurren Norte in the Andes at ~34° S, to develop a minimal glacier surface mass balance model that relies on nearby monthly precipitation and air temperature data as forcing. This basic model is able to explain 78 % of the variance in the annual glacier mass balance record over the 1978–2013 calibration period. An attribution assessment indicates that precipitation variability constitutes the most important forcing modulating annual glacier mass balances at this site. A regionally-averaged series of mean annual streamflow records from both sides of the Andes is then used to estimate, through simple linear regression, this glacier's annual mass balance variations since 1909. The reconstruction model captures 68 % of the observed glacier mass balance variability and shows three periods of sustained positive mass balances embedded in an overall negative trend totaling almost −42 m w.eq. over the past 105 years. The three periods of sustained positive mass balances (centered in the 1920s–1930s, in the 1980s and in the first decade of the 21st century coincide with several documented glacier advances in this region. Similar trends observed in other shorter glacier mass balance series suggest the glaciar Echaurren Norte reconstruction is representative of larger-scale conditions and could be useful for more detailed glaciological, hydrological and climatological assessments in this portion of the Andes.

  5. Meteorological drivers of ablation processes on a cold glacier in the semi-arid Andes of Chile

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    S. MacDonell

    2013-09-01

    Full Text Available Meteorological and surface change measurements collected during a 2.5 yr period are used to calculate surface mass and energy balances at 5324 m a.s.l. on Guanaco Glacier, a cold-based glacier in the semi-arid Andes of Chile. Meteorological conditions are marked by extremely low vapour pressures (annual mean of 1.1 hPa, strong winds (annual mean of 10 m s−1, shortwave radiation receipt persistently close to the theoretical site maximum during cloud-free days (mean annual 295 W m−2; summer hourly maximum 1354 W m−2 and low precipitation rates (mean annual 45 mm w.e.. Snowfall occurs sporadically throughout the year and is related to frontal events in the winter and convective storms during the summer months. Net shortwave radiation provides the greatest source of energy to the glacier surface, and net longwave radiation dominates energy losses. The turbulent latent heat flux is always negative, which means that the surface is always losing mass via sublimation, which is the main form of ablation at the site. Sublimation rates are most strongly correlated with net shortwave radiation, incoming shortwave radiation, albedo and vapour pressure. Low glacier surface temperatures restrict melting for much of the period, however episodic melting occurs during the austral summer, when warm, humid, calm and high pressure conditions restrict sublimation and make more energy available for melting. Low accumulation (131 mm w.e. over the period and relatively high ablation (1435 mm w.e. means that mass change over the period was negative (−1304 mm w.e., which continued the negative trend recorded in the region over the last few decades.

  6. Long-term denudation rates from the Central Andes (Chile estimated from a Digital Elevation Model using the Black Top Hat function and Inverse Distance Weighting: implications for the Neogene climate of the Atacama Desert Tasas de denudación de largo tiempo en los Andes Centrales, Chile, estimadas a partir de un modelo digital de elevación usando la función 'Top Hat' por cierre y la interpolación ponderada por el inverso de la distancia: implicancias del clima Neógeno del Desierto de Atacama

    Directory of Open Access Journals (Sweden)

    Rodrigo Riquelme

    2008-01-01

    Full Text Available A methodology for determining long-term denudation rates from morphologic markers in a Digital Elevation Model (DEM is checked by a comparative study of two drainage basins in the PrecordiUera of the Central Andes. In both cases the initial configuration of an incised pediment surface has been restored by using two different methods: the Black Top Hat (BTH function and the Inverse Distance Weighting (IDW interpolation. Where vertical incision and hillslope erosion are recorded, the IDW appears to be the most adequate to reconstitute the pediment surfaces. Conversely, where only vertical incision is observed, the BTH describes more precisely the former pediment surfaces and it is easier to solve. By subtracting the DEM from the reconstructed marker we calculated an eroded volume, and estimated its uncertainty by considering Root Mean Square Error (RMSE and DEM grid error. For the last ~10 Myr we obtained long-term denudation rates of 7.33±1.6 m/Myr in the San Andrés drainage basin and 13.59±1.9 m/Myr in the El Salado drainage basin. These estimations are largely in agreement with other reported estimates of long-term denudation rates in the Atacama Desert. Comparison with long-term denudation rates reported in a wide range of climatic regimes suggests that our estimates cannot be explained by the current rainfall in the PrecordiUera. However they could be explained by a rainfall similar to that reported 40 km to the east in the Puna. This suggests that during the time span concerned the geomorphologic evolution of the study area, this evolution is dominated by an orographically controlled rainfall pattern. The preserved pediment surface and the small long term denudation rates determined in this study also indicate that the PrecordiUera was never reached by humid tropical air masses and precipitation as currently observed in the Altiplano during the summer monthsUna metodología para determinar tasas de denudación de largo tiempo a partir de

  7. Modelling the hydrological response of debris-free and debris-covered glaciers to present climatic conditions in the semiarid Andes of central Chile

    Science.gov (United States)

    Ayala, Alvaro; Pellicciotti, Francesca; MacDonell, Shelley; McPhee, James; Vivero, Sebastián; Campos, Cristián; Egli, Pascal

    2016-04-01

    We investigate the main contributors to runoff of a 62 km2 glacierized catchment in the semiarid Andes of central Chile, where both debris-free and debris-covered glaciers are present, combining an extensive set of field measurements, remote sensing products and an advanced glacio-hydrological model (TOPKAPI-ETH). The catchment contains two debris-free glaciers reaching down to 3900 m asl (Bello and Yeso Glaciers) and one debris-covered avalanche-fed glacier reaching to 3200 m asl (Piramide Glacier). A unique dataset of field measurements collected in the ablation seasons 2013-14 and 2014-15 included four automatic weather stations, manual measurements of snow depth and debris cover thickness, discharge measurements at glaciers outlets, photographic monitoring of surface albedo as well as ablation stakes measurements and snow pits. TOPKAPI-ETH combines physically-oriented parameterizations of snow and ice ablation, gravitational distribution of snow, snow albedo evolution, glacier dynamics, runoff routing and the ablation of debris-covered ice.We obtained the first detailed estimation of mass balance and runoff contribution of debris-covered glaciers in this mountainous region. Results show that while the mass balance of Bello and Yeso Glaciers is mostly controlled by air temperature lapse rates, the mass balance of Piramide Glacier is governed by debris thickness and avalanches. In fact, gravitational distribution by avalanching on wet years plays a key role and modulates the mass balance gradient of all glaciers in the catchment and can turn local mass balance from negative to positive. This is especially the case for Piramide Glacier, which shows large amounts of snow accumulation below the steep walls surrounding its upper area. Despite the thermal insulation effect of the debris cover, the contribution to runoff from debris-free and debris-covered glaciers is similar, mainly due to elevation differences. At the catchment scale, snowmelt represents more than 60

  8. Neotectónica de los Andes entre 1°N y 47°S (Ecuador, Bolivia y Chile: una revisión

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    A. Lavenu

    2006-12-01

    Full Text Available En los Andes, el estudio del estado de deformación instantánea pleistocena permite reconocer diferentes tipos de comportamientos de la placa continental de Sudamérica a lo largo del margen activo. En Ecuador, el bloque costero está empujado hacia el norte. La costa es afectada por una extensión de dirección N-S, resultado del levantamiento del borde del continente por la subducción de la dorsal asísmica de Carnegie. Por otra parte, la cadena principal sufre una deformación compresiva de dirección E-W. Los altos Andes de Bolivia han sido afectados por una deformación pleistocena extensional de dirección N-S. En el centro y sur de Chile, se observa una partición de la deformación: la zona de antearco ha sido afectada por una compresión N-S y la zona de intraarco por transpresión de dirección NE-SW.

  9. Late cenozoic tectonic and geomorphic evolution of the Patagonian Andes between 42oS and 52oS, southern Chile assessed using fission-track thermochronology

    International Nuclear Information System (INIS)

    Fission-track (FT) analysis has been applied in the Patagonian Andes of southern Chile to assess the late Cenozoic geomorphic and tectonic response of the overriding plate to subduction of the Chile rise active oceanic spreading centre (Thomson et al., 2001). The timing and nature of tectonic uplift and denudation along the southern parts of the major transpression intra-arc Liquine-Ofqui fault (LOF) system have also been investigated (Thomson, 2001, submitted). Results from 130 FT ages (72 zircon and 58 apatite ages) and 39 apatite track length measurements reveal initiation of rapid cooling and denudation at ca. 30 Ma at the western margin of southern continental South America. This was followed by a ca. 200km eastward migration of the locus of maximum denudation to the position of the present day topographic divide between ca. 30 Ma and ca. 12 to 10 Ma. East of the Andean divide less than 3 km of denudation has occurred since the Late Cretaceous. Enhanced denudation is interpreted to be the result of increased tectonic uplift driven by a large increase in convergence rates at ca. 28 to 26 Ma that triggered orographically enhanced precipitation on the west-side of the Patagonian Andes allowing increased erosion by fluvial incision and mass transport processes. The eastward migration of the locus of maximum denudation can be related to either coeval eastward migration of the retro-arc deformation front, the effects of subduction erosion in the overriding plate at the Peru-Chile trench or shallowing of the angle of subduction. Away from the influence of the LOF the process of spreading centre subduction and collision itself coincides with an overall slow-down in denudation rates in the overriding plate most likely caused by a major reduction in the main tectonic force driving tectonic uplift in the upper plate to subduction. In contrast to the Andes south of ca. 46oS, increased cooling and denudation related to transpression induced rock uplift and erosion along

  10. Chile.

    Science.gov (United States)

    1992-05-01

    The background notes on Chile provide a statistical summary of the population, geography, government, and the economy, and more descriptive text on the history, population, government, economy, defense, and foreign relations. In brief, Chile has 13.3 million Spanish Indian (Mestizos), European, and Indian inhabitants and an annual growth rate of 1.6%. 96% are literate. Infant mortality is 18/1000. 34% of the population are involved in industry and commerce, 30% in services, 19% in agriculture and forestry and fishing, 7% in construction, and 2% in mining. The major city is Santiago. The government, which gained independence in 1810, is a republic with executive, legislative, and judicial branches. There are 12 regions. There are 6 major political parties. Suffrage is universal at 18 years. Gross domestic product (GDP) is $29.2 billion. The annual growth rate is 5% and inflation is 19%. Copper, timber, fish, iron ore, nitrates, precious metals, and molybdenum are its natural resources. Agricultural products are 9% of GDP and include wheat, potatoes, corn, sugar beets, onions, beans, fruits, and livestock. Industry is 21% of GDP and includes mineral refining, metal manufacturing, food and fish processing, paper and wood products, and finished textiles. $8.3 billion is the value of exports and $7 billion of imports. Export markets are in Japan, the US, Germany, Brazil, and the United Kingdom. Chile received $3.5 billion in economic aid between 1949-85, but little in recent years. 83% live in urban centers, principally around Santiago. Congressional representation is made on the basis of elections by a unique binomial majority system. Principal government officials are identified. Chile has a diversified free market economy and is almost self-sufficient in food production. The US is a primary trading partner. 49% of Chile's exports are minerals. Chile maintains diplomatic relations with 70 countries, however, relations are strained with Argentina and Bolivia. Relations

  11. Estimation de l'aléa sismique dans les Andes nord équatoriennes

    Directory of Open Access Journals (Sweden)

    1996-01-01

    Full Text Available Les Andes Nord équatoriennes ont connu de nombreux séismes historiques destructeurs. Pour caractériser l’aléa sismique de la région andine, nous avons fait une révision critique de la sismicité historique et de l’ensemble des failles actives de l’Équateur. Les deux sources majeures de l’aléa sismique sont respectivement la subduction superficielle pour la région côtière et le système transpressif des hautes Andes pour la région andine. Ce système est composé de failles décrochantes dextres d’orientation N30-35°E (failles du Rio Chingual-La Sofia et Pallatanga qui limitent respectivement au Nord et au Sud des failles inverses N-S du relais compressif de la vallée interandine (failles de Quito et de Latacunga. L’étude des mécanismes au foyer superficiels des Andes équatoriennes nous a permis de calculer une vitesse de raccourcissement crustal de 4.6 mm/a selon une direction N92°E et d’estimer des temps de récurrence et des périodes de retour. Un séisme de Mw = 5 pourrait se produire tous les 0.5 an, de Mw = 6 tous les 4.5 ans, de Mw = 7 tous les 45.4 ans. De même, sur une période de temps de 33 ans, 66 séismes de Mw=5 peuvent être attendus, 7 séismes de Mw=6 et 1 séisme de Mw=7. Enfin, nous avons estimé pour l’ensemble des sources sismogènes de la région andine des magnitudes maximales probables et des temps de récurrence. Un séisme de magnitude 7 à 7.5 peut se produire sur la faille du Rio Chingual tous les 400±440 ans et de magnitude 6.7 à 7.2 tous les 380±320 ans sur la faille de Pallatanga. Dans la vallée interandine, la faille de Quito est susceptible d’engendrer un séisme de magnitude 6.6 à 7.6 tous les 930±300 ans. LA AMENAZA SÍSMICA EN LOS ANDES ECUATORIANOS. Los Andes del Norte del Ecuador son una región sismogénica mayor, donde se puede contabilizar muchos terremotos históricos destructores. A fin de determinar la amenaza sísmica sobre la región andina, se hizo la asociaci

  12. Parasite loads and altitudinal distribution of Liolaemus lizards in the central Chilean Andes Cargas parasitarias y distribución de lagartijas Liolaemus en los Andes de Chile central

    Directory of Open Access Journals (Sweden)

    JOHN H. CAROTHERS

    2001-09-01

    Full Text Available This study compared the distributions of ten species of Liolaemus lizards in the central Chilean Andes to the distributions of four types of parasites: malaria-causing Plasmodium, gut nematodes, ticks, and mites. We wanted to see if parasite numbers might be a factor in determining distributional limits of the lizards. We found that there was no evidence of malarial infestation of the lizards, that ticks were almost absent, that more often than not mite numbers decreased at the distributional limits of the lizards, and that gut nematodes confined to the herbivorous lizards in our sample may well be beneficial rather than detrimental. Rather than parasitism, other biotic interactions (e.g., predation or competition are more likely candidates as factors influencing lizard elevational distributions, as are abiotic characteristics such as microhabitat availabilities and thermal factorsEste estudio compara las distribuciones de diez especies de lagartijas Liolaemus en los Andes de Chile central, con las distribuciones de cuatro tipos de parásitos: Plasmodium causantes de malaria, nemátodos intestinales, garrapatas y ácaros. Quisimos verificar si los números de parásitos pudieran ser un factor determinante de los límites de distribución de las lagartijas. Encontramos que no había evidencia de infestación por malaria en las lagartijas; que las garrapatas estaban casi ausentes; que los números de ácaros más a menudo decrecían que aumentaban en los límites distribucionales de las lagartijas; y que los nemátodos intestinales confinados a las lagartijas herbívoras en nuestra muestra bien podían ser beneficiosos antes que dañinos. Más bien que parasitismo, otras interacciones bióticas (e.g., depredación o competencia son candidatos más probables como factores que influyen las distribuciones altitudinales de las lagartijas, además de características abióticas tales como la disponibilidad de microhábitats y los factores térmicos

  13. Depositación atmosférica de nitrógeno en un transecto valle longitudinal-cordillera de Los Andes, centro-sur de Chile Atmospheric deposition of nitrogen in a transect from the Central Valley to Cordillera de Los Andes, south-central Chile

    Directory of Open Access Journals (Sweden)

    CARLOS E. OYARZÚN

    2002-03-01

    Full Text Available El aumento de las actividades agrícolas y ganaderas en el centro-sur de Chile puede producir elevadas emisiones de nitrógeno hacia la atmósfera (mayormente NH3. El amoniaco es transportado por corrientes de aire y depositado en el suelo y vegetación. El presente estudio evalúa la depositación atmosférica de compuestos nitrogenados (NO3- y NH4+ en la química de las precipitaciones en un transecto altitudinal de 66 km, desde los alrededores de la ciudad de Osorno (40º 35' S, 72º 57' O, 55 m de altitud hasta la cordillera de Los Andes, Parque Nacional Puyehue (40º 46' S, 72º 11' O, 1.120 m de altitud. En siete sitios, durante el período anual junio-1999 hasta mayo-2000, se registró la precipitación y mensualmente se colectaron muestras de agua para determinar: pH, conductividad y las concentraciones de NO3- y NH4+. La precipitación anual se incrementó desde 1.103 mm en la zona de Osorno hasta 6.799 mm en el sector Antillanca, Parque Nacional Puyehue. Los valores promedio anual del pH registraron escasa variación desde 6,3 en el valle central hasta 5,8 en la cordillera de Los Andes. La conductividad presentó los máximos valores en la proximidad de Osorno (22,9 myS cm-1 para descender a través del transecto en zonas intermedias y alcanzar en la Cordillera de los Andes un valor de 11,3 myS cm-1. Las concentraciones promedio de NO3-Nen la lluvia fluctuaron entre 52,3 myg L-1 en la zona agrícola-ganadera y 6,9 myg L-1 en los bosques del Parque Nacional Puyehue. Las concentraciones de NH4-N variaron entre 699,4 myg L-1 en el sector de Osorno y 37,8 myL-1 en la cordillera de Los Andes. Los valores de N-inorgánico poseen una marcada tendencia estacional en el sector agrícola, con valores máximos en primavera-verano y los mínimos en invierno. Las tasas anuales de depositación atmosférica de NO3-N fluctuaron entre 0,53 y 0,57 kg ha-1 año-1 y las de NH4-N fueron entre 6,4 y 2,8 kg ha-1 año-1 para los sitios agrícola-ganaderos de

  14. Erratic pollination, high selfing levels and their correlates and consequences in an altitudinally widespread above-tree-line species in the high Andes of Chile

    Science.gov (United States)

    Arroyo, Mary T. K.; Muñoz, María S.; Henríquez, Carolina; Till-Bottraud, Irène; Pérez, Fernánda

    2006-09-01

    Unfavorable temperatures and weather conditions for biotic pollination in above-tree-line alpine habitats predict self-compatibility, high levels of autogamy and small flower size ("autogamy reproductive assurance hypothesis"), or alternatively, compensatory measures such as greater flower longevity and larger display size so as to capture scarce visits and maintain outcrossing ("increased pollination probability hypothesis"). We assess these possibilities in a fine-tuned study of Chaetanthera euphrasioides (Asteraceae) populations located above-tree-line in the Andes of central Chile, where prior, independently obtained information on community flower visitation rates is available. Visitation by flies and Andrenid bees was highly erratic in all populations and among years, and the rates well below the community averages. We found evidence for high levels of self-compatibility, equally high autogamous potential, low genetic diversity and high and similar F IS in all populations studied, associated with no clear trends in floral morphology. Strong decoupling of C. euphrasioides reproductive biology with community-level pollinator availability in the alpine fails to support either of the above-mentioned hypotheses and suggests early acquisition of autogamy with present-day pollinator conditions being adequate to maintain low visitation rates at all elevations. Our study provides the only instance where alternative hypotheses on alpine breeding systems have been tested with prior access to independently quantified community-level flower visitation rates.

  15. Positive interactions between alpine plant species and the nurse cushion plant Laretia acaulis do not increase with elevation in the Andes of central Chile.

    Science.gov (United States)

    Cavieres, Lohengrin A; Badano, Ernesto I; Sierra-Almeida, Angela; Gómez-González, Susana; Molina-Montenegro, Marco A

    2006-01-01

    In alpine habitats, positive interactions among plants tend to increase with elevation as a result of altitudinal increase in environmental harshness. However, in mountains located in arid zones, lower elevations are also stressful because of scarce availability of water, suggesting that positive interactions may not necessarily increase with elevation. Here we analysed the spatial association of plant species with the nurse cushion plant Laretia acaulis at two contrasting elevations, and monitored the survival of seedlings of two species experimentally planted within and outside cushions in the semiarid Andes of central Chile. Positive spatial associations with cushions were more frequent at lower elevations. Species growing at the two elevations changed the nature of their association with cushions from neutral or negative at higher elevations to positive at lower elevations. Survival of seedlings was higher within cushions, particularly at lower elevations. The increased facilitation by cushions at lower elevations seems to be related to provision of moisture. This result suggests that cushion plants play a critical role in structuring alpine plant communities at lower elevations, and that climatic changes in rainfall could be very relevant for persistence of plant communities. PMID:16390419

  16. Ten new species from the Patagonian Andes (Argentina and Chile), mostly belonging to a newly designated Stigmella purpurimaculae group (Lepidoptera: Nepticulidae).

    Science.gov (United States)

    Stonis, Jonas R; Remeikis, Andrius; Davis, Donald R

    2014-01-01

    Ten new Stigmella Schrank species are described: Stigmella purpurimaculae Remeikis & Stonis, sp. nov., S. cana Remeikis & Stonis, sp. nov., S. truncata Remeikis & Stonis, sp. nov., S. sceptra Remeikis & Stonis, sp. nov., S. concreta Remeikis & Stonis, sp. nov., S. pseudoconcreta Remeikis & Stonis, sp. nov., S. quadrata Remeikis & Stonis, sp. nov. (all belonging to the newly designated S. purpurimaculae group), and S. semilactea Remeikis & Stonis, sp. nov., S. brutea Remeikis & Stonis, sp. nov., S. pseudodigitata Remeikis & Stonis, sp. nov. (not attributed to a species group) are described from the Andes (Patagonia: Argentina and Chile). For the species of the purpurimaculae group, a partial reduction of phallus, dentate cornuti, and strong development of utriculus (which can be equal or longer of the corpus bursae) are characteristic. Some of the species of the purpurimaculae group were collected near Nothofagus pumilio (Poepp. & Endl.) Krasser, Nothofagaceae, but there is still no confirmation that Nothofagus is a host-plant. All new Stigmella species are illustrated with photographs and drawings of the adults and genitalia. PMID:25543936

  17. Chile.

    Science.gov (United States)

    1986-04-01

    In 1985, Chile's population stood at 12 million, with an annual growth rate of 1.7%. 1984's infant mortality rate was 20/1000 live births and life expectancy was 67 years. The literacy rate was 94%. Of the work force of 3,841,000 in 1985, 15.9% were engaged in agriculture, forestry, and fishing; 31.3% were employed in industry and commerce; 38.6% were in the service sector; 8.7% worked in mining; and 4.4% were employed in construction. Chile's military junta is scheduled to be replaced by an elected legislature in 1990. The GDP was US $19.2 billion in 1984, with an annual real growth rate of 6.3%, and per capita GDP stood at US$1590. Inflation averages 23%. Industry comprises 21% of the GDP. Longterm prospects for the Chilean economy are influenced by a high debt service ratio, very low domestic savings and investment, the prospect of little or no increase in copper prices, and continuing problems in the domestic financial sector. In 1985-88, under the International Monetary Fund macroeconomic program, Chile will strive for moderate economic growth while managing its external debt servicing burden. PMID:12178144

  18. Recent temperature trends in the South Central Andes reconstructed from sedimentary chrysophyte stomatocysts in Laguna Escondida (1742 m a.s.l., 38°28 S, Chile)

    Science.gov (United States)

    De Jong, R.; Schneider, T.; Hernández-Almeida, I.; Grosjean, M.

    2016-02-01

    In this study we present a quantitative, high resolution reconstruction of past austral winter length in the Chilean Andes at 38°S from AD 1920 to 2009. For Laguna Escondida, a nearly pristine lake situated on the flanks of the Andes at 1740 m above sea level, past variability in the duration of the winter season (Days T4 °C) was reconstructed. Because high elevation meteorological stations are absent in this region, the reconstruction provides novel insights into recent temperature trends in the central-southern Andes. As a cold-season temperature proxy, we used chrysophyte stomatocysts. This novel proxy for cold season temperature was so far applied successfully in the European Alps and Pyrenees but has not yet been tested in the Southern Hemisphere. The reconstruction in this study was based on a newly developed Transfer Function to estimate Days T4 °C (number of consecutive days with surface water temperatures at or below 4 °C) from sedimentary stomatocyst assemblages (R2boot = 0.8, RMSEPboot = 28.7 days (= half the standard deviation)). To develop a high quality TF model, sediment traps and thermistors were placed in thirty remote lakes along an altitude gradient (420-2040 m a.s.l.). Complete materials and data were collected in 24 lakes after one year. Detailed statistical analyses indicate that modern stomatocysts primarily respond to the length of the cold season. The TF model was then applied to the sedimentary stomatocysts from a 210Pb-dated short core of L. Escondida. Comparison to independent reanalysis data showed that reconstructed changes in Days T4°C provides detailed information on winter-spring temperature variability since AD 1920. The reconstruction shows that recent warming (onset in AD 1980) in the southern Chilean Andes was not exceptional in the context of the past century. This is in strong contrast to studies from the Northern Hemisphere. The finding is also in contrast to the cooling temperature trends which were detected using

  19. A new species of Phymaturus of the P. mallimaccii Group from the Andes of central Chile (Iguania: Liolaemidae

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    Jaime Troncoso-Palacios

    2014-08-01

    Full Text Available A new species of Phymaturus from the Provincia Mountain in the San Ramón Mountains in the Metropolitan Region of Chile is described. It is a member of the P. palluma Group and the P. mallimaccii subgroup. The new species can be distinguished from other members of the P. mallimaccii subgroup by having a highly fragmented subocular scale (4 or 5, a preocular scale that is smaller than the canthal, males having a olive dorsum with a diffuse pattern of light bands on the paravertebral fields and a light triangle between the shoulders, which has the apex of the triangle oriented toward the snout. The distribution of new species lies south of that of other members of the P. mallimaccii subgroup, from which it is completely isolated. The low abundance of the new species is noteworthy. Information about the natural history of the lizard is provided and some aspects of unnamed populations of Chilean Phymaturus are discussed.

  20. Physical, chemical and mineralogical evolution of the Tolhuaca geothermal system, southern Andes, Chile: Insights into the interplay between hydrothermal alteration and brittle deformation

    Science.gov (United States)

    Sanchez-Alfaro, Pablo; Reich, Martin; Arancibia, Gloria; Pérez-Flores, Pamela; Cembrano, José; Driesner, Thomas; Lizama, Martin; Rowland, Julie; Morata, Diego; Heinrich, Christoph A.; Tardani, Daniele; Campos, Eduardo

    2016-09-01

    In this study, we unravel the physical, chemical and mineralogical evolution of the active Tolhuaca geothermal system in the Andes of southern Chile. We used temperature measurements in the deep wells and geochemical analyses of borehole fluid samples to constrain present-day fluid conditions. In addition, we reconstructed the paleo-fluid temperatures and chemistry from microthermometry and LA-ICP-MS analysis of fluid inclusions taken from well-constrained parageneses in vein samples retrieved from a ~ 1000 m borehole core. Based on core logging, mineralogical observations and fluid inclusions data we identify four stages (S1-S4) of progressive hydrothermal alteration. An early heating event (S1) was followed by the formation of a clay-rich cap in the upper zone (inhibited. In contrast, in the deep upflow zone the less pervasive formation of clay mineral assemblages has allowed retention of rock strength and dilatant behavior during slip, sustaining high permeability conditions. Numerical simulations of heat and fluid flows support our observations and suggest that the presence of a low permeability clay cap has helped increase the duration of high-enthalpy conditions by a factor of three in the deep upflow zone at Tolhuaca geothermal system, when compared with an evolutionary scenario where a clay cap was not developed. Furthermore, our data demonstrate that the dynamic interplay between fluid flow, crack-seal processes and hydrothermal alteration are key factors in the evolution of the hydrothermal system, leading to the development of a high enthalpy reservoir at the flank of the dormant Tolhuaca volcano.

  1. Expanding Geophysical and Geochemical Investigation of Causes of Extraordinary Unrest at the Laguna del Maule (Rhyolitic) Volcanic Field, Southern Andes, Chile

    Science.gov (United States)

    Singer, B. S.

    2014-12-01

    The Laguna del Maule Volcanic Field, Chile, includes an unusually large and recent concentration of silicic eruptions. Since 2007 the crust here has been inflating at an astonishing rate of 25 cm/yr. Findings thus far lead to the hypothesis that the silicic vents have tapped an extensive layer of crystal-poor, rhyolitic melt that began to form atop a magmatic mush zone that was established by ~20 ka with a renewed phase of rhyolite eruptions during the Holocene. Modeling of surface deformation, magnetotelluric data, and gravity changes suggest that magma is currently intruding at a depth of ~5 km. Swarms of volcano-tectonic and long period earthquakes, mostly of M Nanyang Technological University-Singapore, SERNAGEOMIN, OVDAS, USGS, and SEGEMAR-Argentina. Team members will be introduced in this presentation. Our approach includes augmenting the OVDAS array of 6 permanent seisic stations with 40 additional instruments to conduct tomographic, receiver function and ambient noise studies. We continue to collect 4-D gravity data from 37 stations. Surface deformation is monitored via cGPS at 5 permanent receivers and InSAR data. A magnetotelluric survey across the Andes at 36o S is planned. Geochemical studies include mineral zoning and U-Th disequilibrium of zircons to constrain the timing of magma intrusion and mixing events prior to the current unrest. The overall aim is to integrate these observations and to construct numerical models of system dynamics. We are developing communications protocols and a web site to facilitate sharing of findings among the team members and with the public.

  2. Physical, chemical and mineralogical evolution of the Tolhuaca geothermal system, southern Andes, Chile: Insights into the interplay between hydrothermal alteration and brittle deformation

    Science.gov (United States)

    Sanchez-Alfaro, Pablo; Reich, Martin; Arancibia, Gloria; Pérez-Flores, Pamela; Cembrano, José; Driesner, Thomas; Lizama, Martin; Rowland, Julie; Morata, Diego; Heinrich, Christoph A.; Tardani, Daniele; Campos, Eduardo

    2016-09-01

    In this study, we unravel the physical, chemical and mineralogical evolution of the active Tolhuaca geothermal system in the Andes of southern Chile. We used temperature measurements in the deep wells and geochemical analyses of borehole fluid samples to constrain present-day fluid conditions. In addition, we reconstructed the paleo-fluid temperatures and chemistry from microthermometry and LA-ICP-MS analysis of fluid inclusions taken from well-constrained parageneses in vein samples retrieved from a ~ 1000 m borehole core. Based on core logging, mineralogical observations and fluid inclusions data we identify four stages (S1-S4) of progressive hydrothermal alteration. An early heating event (S1) was followed by the formation of a clay-rich cap in the upper zone (creation or reactivation of highly permeable extensional fractures is inhibited. In contrast, in the deep upflow zone the less pervasive formation of clay mineral assemblages has allowed retention of rock strength and dilatant behavior during slip, sustaining high permeability conditions. Numerical simulations of heat and fluid flows support our observations and suggest that the presence of a low permeability clay cap has helped increase the duration of high-enthalpy conditions by a factor of three in the deep upflow zone at Tolhuaca geothermal system, when compared with an evolutionary scenario where a clay cap was not developed. Furthermore, our data demonstrate that the dynamic interplay between fluid flow, crack-seal processes and hydrothermal alteration are key factors in the evolution of the hydrothermal system, leading to the development of a high enthalpy reservoir at the flank of the dormant Tolhuaca volcano.

  3. Arc-oblique fault systems: their role in the Cenozoic structural evolution and metallogenesis of the Andes of central Chile

    Science.gov (United States)

    Piquer, Jose; Berry, Ron F.; Scott, Robert J.; Cooke, David R.

    2016-08-01

    The evolution of the Main Cordillera of Central Chile is characterized by the formation and subsequent inversion of an intra-arc volcano-tectonic basin. The world's largest porphyry Cu-Mo deposits were emplaced during basin inversion. Statistically, the area is dominated by NE- and NW-striking faults, oblique to the N-striking inverted basin-margin faults and to the axis of Cenozoic magmatism. This structural pattern is interpreted to reflect the architecture of the pre-Andean basement. Stratigraphic correlations, syn-extensional deposits and kinematic criteria on fault surfaces show several arc-oblique structures were active as normal faults at different stages of basin evolution. The geometry of syn-tectonic hydrothermal mineral fibers, in turn, demonstrates that most of these structures were reactivated as strike-slip ± reverse faults during the middle Miocene - early Pliocene. Fault reactivation age is constrained by 40Ar/39Ar dating of hydrothermal minerals deposited during fault slip. The abundance and distribution of these minerals indicates fault-controlled hydrothermal fluid flow was widespread during basin inversion. Fault reactivation occurred under a transpressive regime with E- to ENE-directed shortening, and was concentrated around major plutons and hydrothermal centers. At the margins of the former intra-arc basin, deformation was largely accommodated by reverse faulting, whereas in its central part strike-slip faulting was predominant.

  4. Comparison of Airborne LiDAR and Satellite Hyperspectral Remote Sensing to Estimate Vascular Plant Richness in Deciduous Mediterranean Forests of Central Chile

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    Andrés Ceballos

    2015-03-01

    Full Text Available The Andes foothills of central Chile are characterized by high levels of floristic diversity in a scenario, which offers little protection by public protected areas. Knowledge of the spatial distribution of this diversity must be gained in order to aid in conservation management. Heterogeneous environmental conditions involve an important number of niches closely related to species richness. Remote sensing information derived from satellite hyperspectral and airborne Light Detection and Ranging (LiDAR data can be used as proxies to generate a spatial prediction of vascular plant richness. This study aimed to estimate the spatial distribution of plant species richness using remote sensing in the Andes foothills of the Maule Region, Chile. This region has a secondary deciduous forest dominated by Nothofagus obliqua mixed with sclerophyll species. Floristic measurements were performed using a nested plot design with 60 plots of 225 m2 each. Multiple predictors were evaluated: 30 topographical and vegetation structure indexes from LiDAR data, and 32 spectral indexes and band transformations from the EO1-Hyperion sensor. A random forest algorithm was used to identify relevant variables in richness prediction, and these variables were used in turn to obtain a final multiple linear regression predictive model (Adjusted R2 = 0.651; RSE = 3.69. An independent validation survey was performed with significant results (Adjusted R2 = 0.571, RMSE = 5.05. Selected variables were statistically significant: catchment slope, altitude, standard deviation of slope, average slope, Multiresolution Ridge Top Flatness index (MrRTF and Digital Crown Height Model (DCM. The information provided by LiDAR delivered the best predictors, whereas hyperspectral data were discarded due to their low predictive power.

  5. Importance of water quality on plant abundance and diversity in high-alpine meadows of the Yerba Loca Natural Sanctuary at the Andes of north-central Chile Importancia de la calidad del agua sobre la abundancia y diversidad vegetal en vegas altoandinas del Santuario Natural Yerba Loca en los Andes de Chile centro-norte

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    ROSANNA GINOCCHIO

    2008-12-01

    Full Text Available Porphyry Cu-Mo deposits have influenced surface water quality in high-Andes of north-central Chile since the Miocene. Water anomalies may reduce species abundance and diversity in alpine meadows as acidic and metal-rich waters are highly toxic to plants The study assessed the importance of surface water quality on plant abundance and diversity in high-alpine meadows at the Yerba Loca Natural Santuary (YLNS, central Chile (33°15' S, 70°18' W. Hydrochemical and plant prospecting were carried out on Piedra Carvajal, Chorrillos del Plomo and La Lata meadows the growing seasons of 2006 and 2007. Direct gradient analysis was performed through canonical correspondence analysis (CCA to look for relationships among water chemistry and plant factors. High variability in water chemistry was found inside and among meadows, particularly for pH, sulphate, electric conductivity, hardness, and total dissolved Cu, Zn, Cd, Pb and Fe. Data on species abundance and water chemical factors suggests that pH and total dissolved Cu are very important factor determining changes in plant abundance and diversity in study meadows. For instance, Festuca purpurascens, Colobanthus quitensis, and Arenaria rivularis are abundant in habitals with Cu-rich waters while Festuca magellanica, Patosia clandestina, Plantago barbata, Werneria pygmea, and Erigeron andícola are abundant in habitals with dilute waters.Los megadepósitos de pórfidos de Cu-Mo han influido sobre la calidad de las aguas superficiales en las zonas altoandinas del centro-norte de Chile desde el Mioceno. Estas alteraciones en la calidad de las aguas podrían afectar negativamente a la vegetación presente en las vegas altoandinas, ya que las aguas acidas y ricas en metales son altamente tóxicas para las plantas. En este estudio se evaluó el efecto de la calidad de las aguas en la abundancia y diversidad florística de las vegas altoandinas del Santuario de la Naturaleza Yerba Loca (SNYL, en Chile central (33

  6. Floristic changes in alpine plant communities induced by the cushion plant Azorella madreporica (Apiaceae in the Andes of central Chile Cambios florísticos en comunidades de plantas alpinas inducidos por la planta en cojín Azorella madrepórica (Apiaceae en los Andes de Chile central

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    CONSTANZA L QUIROZ

    2009-06-01

    Full Text Available It is well known that the number of plant species associated with nurse plants increases with elevation. However, studies conducted so far have largely ignored the effect of nurse plants on other community attributes, such as the species abundances, diversity and evenness. Moreover, changes in these community attributes along environmental gradients have also been seldom examined. The present study evaluates the effect of the cushion plant Azorella madrepórica (Apiaceae on species richness, species abundance, diversity and evenness of vascular plants at two elevations in the Andes of central Chile. Theoretically, the impact of this nurse cushion plant on these community attributes should be grater at a higher elevation. Results showed that the proportion of plant species associated with cushion plants increases with elevation, and the abundance of some species is also greater within cushions than on bare ground. Although the proportion of species growing within cushions increased with elevation, diversity and evenness were higher on bare ground. This is due to some few species that attained very high densities within cushions, generating assemblages highly dominated by some few species. Ordination analyses indicated differences in species assemblages within and outside A. madrepórica at the higher elevation. Therefore, the influence of cushion plants on community structure changes with elevation. Accordingly, we suggest that attributes other than species richness must be included in future studies in order to analyze the impact of nurse species on community structure along environmental gradients.Se sabe que el número de especies asociado a plantas nodrizas aumenta con la altitud. Sin embargo, el efecto de plantas nodrizas sobre otros atributos de las comunidades, como la abundancia de especies, diversidad y equidad, ha sido largamente ignorado. Más aún, cambios en estos atributos en gradientes ambientales han sido pocas veces examinados

  7. Nurse effect in seedling establishment: facilitation and tolerance to damage in the Andes of central Chile Efecto nodriza en el establecimiento de plántulas: facilitación y tolerancia al daño en los Andes de Chile central

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    IAN S ACUÑA-RODRÍGUEZ

    2006-09-01

    Full Text Available Nurse effects, which occur when one plant species enhances the survival or growth of another plant species, are predicted to be most relevant in stressful environments. These effects are particulary important during seedling establishment due to their vulnerability to both biotic and abiotic factors, such as herbivory and drought. Tolerance to herbivory reflects the degree to which plants are able to regrow and reproduce after damage, and should vary with resource availability. In the high Andes of central Chile, the cushion plant Laretia acaulis (Apiaceae acts as a buffer against environmental stress, enhancing survival of several associated plant species. We hypothesized that tolerance to herbivory of seedlings growing inside the canopy of L. acaulis should be greater than that of seedlings growing outside the cushion plant. We conducted a field experiment to test this hypothesis for two native perennial species in the high Andes of central Chile: Hordeum comosum (Poaceae and Haplopappus anthylloides (Asteraceae. Seedlings of each species were planted inside and outside L. acaulis cushions and half of them received manual damage (50 % foliar tissue removed. Seedlings growing inside the nurse species showed high survival independent of the damage treatment. Whereas position (inside or outside the cushion plant did not affect tolerance of Haplopappus anthylloides, it significantly affected tolerance of Hordeum comosum. Thus, we found similar survival of damaged and control seedlings of H. comosum inside the cushions, but survival of damaged seedlings in the bare ground was lower than that of control seedlings. We verified the occurrence of nurse effects of Laretia acaulis on the establishment of both species, and detected enhancement of tolerance to damage in Hordeum comosum in this stressful habitatSe ha sugerido que el efecto nodriza, el cual se evidencia cuando una especie vegetal incrementa la supervivencia o el crecimiento de otra, es m

  8. August-September 2003 small vulcanian eruption at the Nevados de Chillán Volcanic Complex (36°50'S, Southern Andes (Chile

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    José A. Naranjo

    2004-12-01

    Full Text Available During the winter months of August-September 2003 a small (VEI=0-1 eruption took place at the 9 km long fissure-like Nevados de Chillán Volcanic Complex (36°50'S, that includes Nuevo (formed between 1906 and 1945 and Arrau (formed in the 1973-1986 period volcanoes. Only the local inhabitants and tourists of the ski resort located at the foothills noted the eruption. From August 29 to September 4, 2003, low-magnitude explosive events occurred and brown-greyish to white gas and ash columns reached up to 400 to 500 m above the crater, rising at periods that lasted for 20 to 25 minutes. After the first week, explosions became more sporadic and occurred at two-three day intervals. Strong prevailing winds from the north dispersed the low-altitude plume to the SSE until the eruption finally stopped by the middle of September. A new compound crater is now present in the saddle between Nuevo and Arrau volcanoes. This 64 m fissure-like double crater is surrounded by an area of intense fumaroles near to Nuevo volcano suggesting the renewal of activity in the complexPequeña erupción vulcaniana de agosto-septiembre en el Complejo Volcánco Nevados de Chillán (36°50'S, Andes del sur (Chile. Durante los meses invernales de agosto y septiembre de 2003 ocurrió una pequeña erupción (IEV=0-1 en la fisura de 9 km de largo del Complejo Volcánico Nevados de Chillán (36°50'S, que incluye a los volcanes Nuevo (formado entre 1906 y 1945 y Arrau (formado entre 1973 y 1986. La erupción fue advertida únicamente por los lugareños y los visitantes del centro invernal situado a los pies del volcán. La semana del 20 al 27 de agosto 2003 se produjeron eventos explosivos de baja magnitud con columnas de gas y ceniza de color pardo-grisáceo y blanco que alcanzaron alturas de 400 a 500 m con períodos de 20 a 25 minutos. Después de la primera semana las explosiones se hicieron más esporádicas ocurriendo a intervalos de 2 a 3 días. Los fuertes vientos

  9. Parasite loads and altitudinal distribution of Liolaemus lizards in the central Chilean Andes Cargas parasitarias y distribución de lagartijas Liolaemus en los Andes de Chile central

    OpenAIRE

    JOHN H. CAROTHERS; Jaksic, Fabián M

    2001-01-01

    This study compared the distributions of ten species of Liolaemus lizards in the central Chilean Andes to the distributions of four types of parasites: malaria-causing Plasmodium, gut nematodes, ticks, and mites. We wanted to see if parasite numbers might be a factor in determining distributional limits of the lizards. We found that there was no evidence of malarial infestation of the lizards, that ticks were almost absent, that more often than not mite numbers decreased at the distributional...

  10. Estimation of slip scenarios of mega-thrust earthquakes and strong motion simulations for Central Andes, Peru

    Science.gov (United States)

    Pulido, N.; Tavera, H.; Aguilar, Z.; Chlieh, M.; Calderon, D.; Sekiguchi, T.; Nakai, S.; Yamazaki, F.

    2012-12-01

    We have developed a methodology for the estimation of slip scenarios for megathrust earthquakes based on a model of interseismic coupling (ISC) distribution in subduction margins obtained from geodetic data, as well as information of recurrence of historical earthquakes. This geodetic slip model (GSM) delineates the long wavelength asperities within the megathrust. For the simulation of strong ground motion it becomes necessary to introduce short wavelength heterogeneities to the source slip to be able to efficiently simulate high frequency ground motions. To achieve this purpose we elaborate "broadband" source models constructed by combining the GSM with several short wavelength slip distributions obtained from a Von Karman PSD function with random phases. Our application of the method to Central Andes in Peru, show that this region has presently the potential of generating an earthquake with moment magnitude of 8.9, with a peak slip of 17 m and a source area of approximately 500 km along strike and 165 km along dip. For the strong motion simulations we constructed 12 broadband slip models, and consider 9 possible hypocenter locations for each model. We performed strong motion simulations for the whole central Andes region (Peru), spanning an area from the Nazca ridge (16^o S) to the Mendana fracture (9^o S). For this purpose we use the hybrid strong motion simulation method of Pulido et al. (2004), improved to handle a general slip distribution. Our simulated PGA and PGV distributions indicate that a region of at least 500 km along the coast of central Andes is subjected to a MMI intensity of approximately 8, for the slip model that yielded the largest ground motions among the 12 slip models considered, averaged for all assumed hypocenter locations. This result is in agreement with the macroseismic intensity distribution estimated for the great 1746 earthquake (M~9) in central Andes (Dorbath et al. 1990). Our results indicate that the simulated PGA and PGV for

  11. Ages and geochemistry of Mesozoic-Eocene back-arc volcanic rocks in the Aysén region of the Patagonian Andes, Chile

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    Miguel A. Parada

    2001-07-01

    Full Text Available Eighteen new radiometric ages (fourteen 40Ar-39Ar, four K-Ar, combined with previously published ages, confirm the existence of three main extensional back-arc volcanic events, previously defined by stratigraphic relationships, in Chilean Patagonia (Aysén region. These three events developed during the Middle Jurassic -Early Cretaceous (160-130 Ma. Cretaceous (114-75 Ma, and Eocene (55-46 Ma. Based on distinct geochemical data and Sr-Nd isotopic characteristics of the back-arc volcanic rocks collected north and south of 46°30'S, two Mesozoic-Eocene magmatic domains are recognized: Northern Magmatic Domain (NMD and Southern Magmatic Domain (SMD. Most analyzed basalts and intermediate volcanic rocks of the NMD have alkaline affinities and depleted to slightly depleted Sr-Nd isotopic values similar to those derived from an asthenosphere-dominated source. The SMD mafic volcanic rocks have a subalkaline character and more enriched Sr-Nd isotopic signatures, comparable to those derived from a lithospheric source. The felsic volcanic rocks of the SMD have lower eNd values and slightly higher initial 87Sr/86Sr ratios than the NMD felsic rocks, suggesting a larger crustal contribution in the magma sources. The geochemical and isotopic distinction between NMD and SMD felsic rocks could be influenced by the presence of Paleozoic metamorphic rocks as basement of the volcanic rocks of the SMD. Moreover, the compositional distinction between basalts of both domains may correspond to differences in magnitude of extension, the NMD being the one where the extension would have been greater and, consequently, the lithosphere thinnerEdades y geoquímica de las rocas volcánicas del trasarco del Mesozoico-Eoceno en la región de Aysén de los Andes patagónicos, Chile. Diez y ocho nuevas edades radiométricas (catorce 40Ar-39Ar, cuatro K-Ar junto con las ya publicadas confirman la existencia de tres eventos volcánicos (previamente definidos por relaciones

  12. Identificación de Hantavirus Andes en Rattus norvegicus Identification of Andes Hantavirus in Rattus norvegicus

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    J Fernández

    2008-01-01

    Full Text Available En Chile y Argentina la especie Oligoryzomys longicaudatus ha sido identificada como el principal reservorio para Virus Andes (ANDV. El objetivo de este trabajo es reportar la presencia del virus Andes en Rattus norvergicus, roedor urbano recolectado de un muestreo en San Diego del Cristo, comuna de Melipilla, Región Metropolitana. La presencia del virus Andes en Rattus norvegicus podría indicar la importancia de otros roedores como eventuales vectores virales.In Chile and Argentina Oligoryzomys longicaudatus has been identified as the main reservoir for Hantavirus Andes. The aim of this work was to report the presence of Hantavirus Andes in Rattus norvegicus, an urban rodent collected during sampling in San Diego del Cristo, Melipilla, Metropolitan Region. The existence of Hantavirus Andes in Rattus norvegicus could indicate the importance of other rodents as possible viral vectors.

  13. Estimates of Carbon Reservoirs in High-Altitude Wetlands in the Colombian Andes

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    Enrique Javier Peña

    2009-10-01

    Full Text Available The observed increase in emission of greenhouse gases, with attendant effects on global warming, have raised interests in identifying sources and sinks of carbon in the environment. Terrestrial carbon (C sequestration involves capture of atmospheric C through photosynthesis and storage in biota, soil and wetlands. Particularly, wetland systems function primarily as long-term reservoirs for atmospheric carbon dioxide (CO2 and as sources of atmospheric methane (CH4. The objective of this study was to evaluate the patterns of carbon reservoirs in two high-altitude wetlands in the central Andean mountain of Colombia. Carbon cycle in both systems is related mainly with the plant biomass dynamics from the littoral zone. Thus, total organic carbon concentrate an average up to 329 kg of N ha-1 and 125 kg of P ha-1 every year vs only 17 kg N ha-1 and 6 kg P ha-1 in the water column of the limnetic zone in the wetland, evidencing spatial differences in carbon concentrations for these types of ecosystems. Results revealed that these systems participate in the balance and sequestration of carbon in the Colombian Andes.

  14. Snow water equivalent spatiotemporal variability estimation in the Andes Cordillera through distributed energy balance modeling and intensive-study catchments.

    Science.gov (United States)

    McPhee, J. P.; Cornwell, E.; Molotch, N. P.

    2015-12-01

    Seasonal snow cover is the primary water resource precursor for human use and environmental sustain along the extratropical Andes Cordillera. This research provides high-resolution distributed estimates of end-of-winter and spring snow water equivalent over a 152,000-km2 domain, based on remotely sensed snow cover and a simplified snowpack energy balance model. Important data for model validation was obtained through a sustained effort aimed at monitoring snow conditions throughout the domain from newly installed sensors and snow surveys. Peak SWE estimates show an overall coefficient of determination R2 of 0.61 compared to observations at 12 automatic snow water equivalent sensors distributed across the model domain between latitudes 30º S and 37º S, with R2 values between 0.32 and 0.88. Estimated patterns of snow accumulation reflect appropriately the dominant effect of elevation, and suggest that the current government operational snow observation network may be inadequate under future climate change scenarios. Several insights can be obtained by analyzing the shortcomings of the modeling results when compared with high-resolution time series of energy and mass balance, as well as with distributed SWE observations obtained at experimental catchments. The results presented here have the potential of informing applications such as seasonal forecast model assessment and improvement, regional climate model validation, as well as evaluation of observational networks and water resource infrastructure development.

  15. Geochronology (40Ar/39Ar, K-Ar and He-exposure ages of Cenozoic magmatic rocks from Northern Chile (18-22°S: implications for magmatism and tectonic evolution of the central Andes

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    Gerhard Wörner

    2000-12-01

    Full Text Available K-Ar and Ar/Ar ages from magmatic rocks of northern Chile (18-22°S describe duration and extent of the Tertiary and Quaternary magmatic evolution and date major tectonic events in northernmost Chile. This paper summarizes new K-Ar and Ar-Ar mineral and whole rock ages for intrusive rocks from the Precordillera, Tertiary ignimbrites and andesitic stratovolcanoes from the Western Andean Escarpment at 18°S (WARP and the volcanic front. Intrusive rocks of the Precordillera (Quebrada Paguana, Quebrada Blanca, Quebrada Choja, Quebrada Guatacondo, Cerro Chandacolla represent the Cretaceous to Eocene magmatic arc system and gave ages between 45 and 35 Ma. Younger ages on intrusive rocks are invariably caused by deuteric alteration. Ignimbrites of the Putani and Oxaya formations gave Ar-Ar sanidine ages around 24.2 to 24.8 Ma and 22.8 to 19.4 Ma, respectively. Andesitic stratovolcanoes, which directly overlie Oxaya ignimbrites east of the Western Cordillera gave ages of 20.3 Ma (Cordon Quevilque to 9.0 Ma (Cerro Margarita. Samples from the Miocene to Pleistocene arc system on the Chilean Altiplano underlying the volcanoes of the active volcanic front have been dated between 10.5 to ~3 Ma. A widespread ignimbrite can be correlated from the Lauca basin to the Pacific coast and to the east to occurrences of near Pérez. Repeated Ar-Ar sanidine dating of the Lauca-Pérez-ignimbrite resulted in highly concordant ages of 2.71±0.25 Ma, 2.72 Ma±0.01 Ma, and 2.73±0.11 Ma. Rocks from the active chain (Volcanic Cordillera gave ages younger than 0.9 Ma (Volcán Irruputuncu, Volcán Olca, Volcán Aucanquilcha, Volcán Ollagüe, Volcán Poruñita. These new data are used to constrain Miocene stratigraphy and tectonic movements as well as the timing of uplift and sedimentary response at the Western Andean Escarpment within the framework of the tectonic evolution of the Central AndesGeocronología (49Ar/39Ar, K-Ar y edades He de exposición de rocas cenozoicas del

  16. Combining point and distributed snowpack data with landscape-based discretization for hydrologic modeling of the snow-dominated Maipo River Basin, in the semi-arid Andes central Chile

    Science.gov (United States)

    Videla Giering, Y. A., III; McPhee, J. P.

    2015-12-01

    Snow hydrology in mountain environments plays an important role in the availability of hydrological resources in warm climate areas and height effects, since the magnitude of snowpack, its spatial and temporal distribution is very important to determine the availability of water in the snowmelt season and take forward different productive activities This investigation models and assess the main phenomena hydrological cycle of snow using the software Cold Region Hydrological Model (Pomeroy et al., 2007). The software is a physically based model developed by the centre for hydrology, University of Saskatchewan. The aim of this model is to have a better understanding of hydrological processes involved in cold environments, which are particular in the sense that a host of specific phenomena such as snow and ice accumulation, transport and melt, infiltration through frozen soils, and the like, control the hydrograph timing) The analysis involved the development of a hydrologic model for the Upper Maipo River Basin, with elevations between 800 and 6500 meters above sea level and 5000-km^2 watershed in the Andes of Central Chile which supplies water resources to the capital city of Santiago (7 million inhabitants), to a thriving agricultural region, as well as to hydropower and large mining activities. The paper concludes that there is a differential distribution of snow cover in the study area, determined mainly by steep terrain geomorphology. These factors have been considered in the parameterization of the model, showing considerable variation in storage time, redistributions by blowing snow, melting intervals, infiltration rates and drainage basin. The fictional scenarios modeled demonstrate noticeable changes in the hydrograph, showing the fragile climate and hydrological condition of this basin of Central Chile.

  17. Incomplete trimorphic incompatibility expression in Oxalis compacta Gill. ex Hook. et Arn. subsp. compacta in the central Chilean Andes Expresión incompleta de incompatibilidad trimórfica en Oxalis compacta Gill. ex Hook. et Arn. subsp. compacta en los Andes de Chile central

    Directory of Open Access Journals (Sweden)

    MARY T. K ARROYO

    2012-01-01

    Full Text Available The expression of trimorphic incompatibility was investigated in a high altitude population of Oxalis compacta subsp. compacta distributed in the upper alpine belt (3100-3470 m of the central Chile Andes. Stigma-anther reciprocity (2 populations, morph representation (7 populations, unassisted selfing capacity and open-pollination fruit set (6 populations were determined. O. compacta ssp. compacta es highly dependent on external pollinators. Although it has typical tristylous flowers, considerable seed set is possible following illegitimate intermorph and intramorph cross pollination. Open pollination fruit set varied from 9-83% and on average was lower in the higher-elevation populations. The possibility of seed set following two kinds of illegitimate cross pollination is seen as a means of enhancing reproductive output by enabling more effective use of the limited pollinator resource in the high alpine environment, where fruit set shows high inter-annual variability and there is some evidence for pollination limitation in Oxalis compacta subsp. compacta.Se investigó la expresión de incompatibilidad trimórfica en una población de Oxalis compacta subsp. compacta distribuida en la zona alpina superior de los Andes de Chile central. Se determinó la reciprocidad de los estigmas y anteras (dos poblaciones, representación de morfos florales (7 poblaciones, capacidad para autofecundación no asistida y polinización abierta (6 poblaciones. O. compacta subsp. compacta es altamente dependiente de polinizadores externos. No obstante la presencia de flores tristilicas, las dos categorías ilegítimas de polinización dieron semillas. La producción de frutos mediante polinización abierta fluctuó entre 9-83% y en promedio fue menor en las poblaciones de mayor elevación. Se plantea que la capacidad de formar semillas mediante polinización ilegítima permitirá el uso más eficaz del recurso limitado de polinización en la zona andina superior

  18. Sediment yield along the Andes: continental budget, regional variations, and comparisons with other basins from orogenic mountain belts

    Science.gov (United States)

    Latrubesse, Edgardo M.; Restrepo, Juan D.

    2014-07-01

    We assess the sediment yield at 119 gauging stations distributed from Colombia to Patagonia, covering the different morphotectonic and morphoclimatic settings of the Andes. The most productive areas are the Meta River basin within the northern Andes and the Bolivian and northern Argentina-Chaco systems, which produce an average of 3345, 4909 and 2654 t km2 y- 1 of sediment, respectively. The rivers of the northern and central Andes (excluding the Pacific watersheds of Peru, northern Chile, and central Argentina) have a weighted mean sediment yield of 2045 t km- 2 y- 1 and produce 2.25 GTy- 1 of total sediment. A major constraint estimating the Andean continental budget of sediment yield lies in the lack of gauging data for the Peruvian region. Using the available gauge stations, the regional sediment yield appears underestimated. Assuming a higher value of sediment yield for the Peruvian Andes, the total budget for the whole central Andes could range between 2.57 GT y- 1 and 3.44 GT y- 1. A minimum of ~ 0.55 GT y- 1 and a probable maximum of ~ 1.74 GT y- 1 of sediment are deposited in the intramontane and surrounding proximal sedimentary basins. The magnitude of sediment yield in the Andes is comparable to other rivers draining orogenic belts around the world.

  19. Tectonic control on rock uplift, exhumation, and topography above an oceanic ridge collision: Southern Patagonian Andes (47°S), Chile

    Science.gov (United States)

    Georgieva, Viktoria; Melnick, Daniel; Schildgen, Taylor F.; Ehlers, Todd A.; Lagabrielle, Yves; Enkelmann, Eva; Strecker, Manfred R.

    2016-06-01

    The subduction of bathymetric anomalies at convergent margins can profoundly affect subduction dynamics, magmatism, and the structural and geomorphic evolution of the overriding plate. The Northern Patagonian Icefield (NPI) is located east of the Chile Triple Junction at ~47°S, where the Chile Rise spreading center collides with South America. This region is characterized by an abrupt increase in summit elevations and relief that has been controversially debated in the context of geodynamic versus glacial erosion effects on topography. Here we present geomorphic, thermochronological, and structural data that document neotectonic activity along hitherto unrecognized faults along the flanks of the NPI. New apatite (U-Th)/He bedrock cooling ages suggest faulting since 2-3 Ma. We infer the northward translation of an ~140 km long fore-arc sliver -- the NPI block -- results from enhanced partitioning of oblique plate convergence due to the closely spaced collision of three successive segments of the Chile Rise. In this model, greater uplift occurs in the hanging wall of the Exploradores thrust at the northern leading edge of the NPI block, whereas the Cachet and Liquiñe-Ofqui dextral faults decouple the NPI block along its eastern and western flanks, respectively. Localized extension possibly occurs at its southern trailing edge along normal faults associated with margin-parallel extension, tectonic subsidence, and lower elevations along the Andean crest line. Our neotectonic model provides a novel explanation for the abrupt topographic variations inland of the Chile Triple Junction and emphasizes the fundamental effects of local tectonics on exhumation and topographic patterns in this glaciated landscape.

  20. Geometry of the inverted Cretaceous Chañarcillo Basin based on 2-D gravity and field data. An approach to the structure of the western Central Andes of northern Chile

    Directory of Open Access Journals (Sweden)

    F. Martínez

    2015-08-01

    Full Text Available This paper discusses an integrated approach that provides new ideas about the structural geometry of the NNE-striking, Cretaceous Chañarcillo Basin located along the eastern Coastal Cordillera in the western Central Andes of northern Chile (27–28° S. The results obtained from the integration of two transverse (E–W gravity profiles with previous geological information, show that the architecture of this basin is defined by a large NNE–SSE-trending and east-vergent anticline ("Tierra Amarilla Anticlinorium", which is related to the positive reactivation of a former Cretaceous normal fault (Elisa de Bordos Master Fault. Moreover, intercalations of high and low gravity anomalies and steep gravity gradients reveal a set of buried, west-tilted half-grabens associated with a synthetic normal fault pattern. These results, together with the uplift and folding style of the Cretaceous syn-rift recognized within the basin, suggest that their complete structural geometry could be explained by an inverted fault system linked to the shortening of pre-existing Cretaceous normal fault systems. Ages of the synorogenic deposits exposed unconformably over the frontal limb of the Tierra Amarilla Anticlinorium confirm a Late Cretaceous age for the Andean deformation and tectonic inversion of the basin.

  1. Bias adjustment of satellite-based precipitation estimation using gauge observations: A case study in Chile

    Science.gov (United States)

    Yang, Zhongwen; Hsu, Kuolin; Sorooshian, Soroosh; Xu, Xinyi; Braithwaite, Dan; Verbist, Koen M. J.

    2016-04-01

    Satellite-based precipitation estimates (SPEs) are promising alternative precipitation data for climatic and hydrological applications, especially for regions where ground-based observations are limited. However, existing satellite-based rainfall estimations are subject to systematic biases. This study aims to adjust the biases in the Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks-Cloud Classification System (PERSIANN-CCS) rainfall data over Chile, using gauge observations as reference. A novel bias adjustment framework, termed QM-GW, is proposed based on the nonparametric quantile mapping approach and a Gaussian weighting interpolation scheme. The PERSIANN-CCS precipitation estimates (daily, 0.04°×0.04°) over Chile are adjusted for the period of 2009-2014. The historical data (satellite and gauge) for 2009-2013 are used to calibrate the methodology; nonparametric cumulative distribution functions of satellite and gauge observations are estimated at every 1°×1° box region. One year (2014) of gauge data was used for validation. The results show that the biases of the PERSIANN-CCS precipitation data are effectively reduced. The spatial patterns of adjusted satellite rainfall show high consistency to the gauge observations, with reduced root-mean-square errors and mean biases. The systematic biases of the PERSIANN-CCS precipitation time series, at both monthly and daily scales, are removed. The extended validation also verifies that the proposed approach can be applied to adjust SPEs into the future, without further need for ground-based measurements. This study serves as a valuable reference for the bias adjustment of existing SPEs using gauge observations worldwide.

  2. Estimating glacier and snowmelt contributions to stream flow in a Central Andes catchment in Chile using natural tracers

    OpenAIRE

    Rodriguez, M.; N. Ohlanders; McPhee, J

    2014-01-01

    This paper presents a methodology for hydrograph separation in high elevation watersheds, which aims at identifying individual flow sources such as snow- and ice melt, rainfall and soil water. Daily summer and bi-daily spring water samples from the outlet of the Juncal River were analyzed for all major ions as well as stable water isotopes, δ18O and δ2H. Additionally, various water sources such as rain, springs, snow- and glacial melt were sampled thr...

  3. Que sait-on des précipitations en altitude dans les Andes semi-arides du Chili ? (What do we know about high-altitude precipitation in the semi-arid Andes of Chile?)

    OpenAIRE

    Bourgin, P.Y.; V. Andréassian; Gascoin, S.; Valéry, A.

    2012-01-01

    Mapping precipitations on a regular grid is often required for hydrological and ecological modelling. The spatial interpolation methods are generally used to estimate such a distribution from ground-based measurements. In the case of mountainous areas, the estimation of precipitation amounts is still a challenging task and the results of spatial interpolation should be verified as much as possible. Here we describe a three-steps method for the validation of a precipitation map. This is used i...

  4. "Un devorador de su propia especie". Violencia, justicia y cultura popular en Santa Rosa de los Andes: las formas de la autoridad a los ojos de un peón de oficio matador, Chile 1805

    Directory of Open Access Journals (Sweden)

    Daniel Moreno Bazaes

    2016-01-01

    Full Text Available A través del análisis microhistórico del proceso judicial seguido por las autoridades de la villa de Santa Rosa de Los Andes e intervenido por la Real Audiencia de Santiago contra Juan Francisco Varas, “peón-gañan” de la hacienda de Llay-Llay, responsable de a lo menos seis homicidios y otros tantos crímenes que atentaron contra el orden local y el gobierno civil, se pretende dar cuenta de los pormenores de la organización social en el Valle del Aconcagua a fines del siglo XVIII y durante los primeros años del siglo XIX. De modo que a través de la observación de las tensiones generadas por el uso indiscriminado de la violencia, el desacato y la desobediencia a la autoridad local, se desea mostrar uno de los rostros más violentos que presentaron los procesos de campesinización en Chile durante el periodo colonial, indagando en las formas en que los contemporáneos, la administración y autoridades locales reaccionaron frente a este tipo de prácticas consideradas como intolerables y excesivas. Por supuesto, se pretende dar cuenta delos mecanismos desplegados por controlar ese tipo de conductas y desde ahí profundizar en los horizontes que adoptaron lo justo y la autoridad frente a una cultura popular que se configuró al margen de la “civilidad”.

  5. The ANDES Deep Underground Laboratory

    CERN Document Server

    Bertou, X

    2013-01-01

    ANDES (Agua Negra Deep Experiment Site) is a unique opportunity to build a deep underground laboratory in the southern hemisphere. It will be built in the Agua Negra tunnel planned between Argentina and Chile, and operated by the CLES, a Latin American consortium. With 1750m of rock overburden, and no close- by nuclear power plant, it will provide an extremely radiation quiet environment for neutrino and dark matter experiments. In particular, its location in the southern hemisphere should play a major role in understanding dark matter modulation signals.

  6. Late Mesozoic to Paleogene stratigraphy of the Salar de Atacama Basin, Antofagasta, Northern Chile: Implications for the tectonic evolution of the Central Andes

    Science.gov (United States)

    Mpodozis, Constantino; Arriagada, César; Basso, Matilde; Roperch, Pierrick; Cobbold, Peter; Reich, Martin

    2005-04-01

    The Salar de Atacama basin, the largest "pre-Andean" basin in Northern Chile, was formed in the early Late Cretaceous as a consequence of the tectonic closure and inversion of the Jurassic-Early Cretaceous Tarapacá back arc basin. Inversion led to uplift of the Cordillera de Domeyko (CD), a thick-skinned basement range bounded by a system of reverse faults and blind thrusts with alternating vergence along strike. The almost 6000-m-thick, upper Cretaceous to lower Paleocene sequences (Purilactis Group) infilling the Salar de Atacama basin reflects rapid local subsidence to the east of the CD. Its oldest outcropping unit (Tonel Formation) comprises more than 1000 m of continental red sandstones and evaporites, which began to accumulate as syntectonic growth strata during the initial stages of CD uplift. Tonel strata are capped by almost 3000 m of sandstones and conglomerates of western provenance, representing the sedimentary response to renewed pulses of tectonic shortening, which were deposited in alluvial fan, fluvial and eolian settings together with minor lacustrine mudstone (Purilactis Formation). These are covered by 500 m of coarse, proximal alluvial fan conglomerates (Barros Arana Formation). The top of the Purilactis Group consists of Maastrichtian-Danian alkaline lava and minor welded tuffs and red beds (Cerro Totola Formation: 70-64 Ma K/Ar) deposited during an interval of tectonic quiescence when the El Molino-Yacoraite Late Cretaceous sea covered large tracts of the nearby Altiplano-Puna domain. Limestones interbedded with the Totola volcanics indicate that this marine incursion advanced westwards to reach the eastern CD slope. CD shortening in the Late Cretaceous was accompanied by volcanism and continental sedimentation in fault bounded basins associated to strike slip along the north Chilean magmatic arc to the west of the CD domain, indicating that oblique plate convergence prevailed during the Late Cretaceous. Oblique convergence seems to have

  7. Glacier meltwater flow paths and storage in a geomorphologically complex glacial foreland: The case of the Tapado glacier, dry Andes of Chile (30°S)

    Science.gov (United States)

    Pourrier, J.; Jourde, H.; Kinnard, C.; Gascoin, S.; Monnier, S.

    2014-11-01

    The Tapado catchment is located in the upper Elqui river basin (4000-5550 m) in northern Chile. It comprises the Tapado glacial complex, which is an assemblage of the Tapado glacier and the glacial foreland (debris-covered glacier, rock glacier, and moraines). Although the hydrological functioning of this catchment is poorly known, it is assumed to actively supply water to the lower semi-arid areas of the Elqui river basin. To improve our knowledge of the interactions and water transfers between the cryospheric compartment (glacier, debris-covered glacier, and rock glacier) and the hydrological compartment (aquifers, streams), the results of monitoring of meteorological conditions, as well as discharge, conductivity and temperature of streams and springs located in the Tapado catchment were analyzed. The hydrological results are compared to results inferred from a ground penetrating radar (GPR) survey of the underground structure of the glacial foreland. Water production from the Tapado glacier was shown to be highly correlated with daily and monthly weather conditions, particularly solar radiation and temperature. The resulting daily and monthly streamflow cycles were buffered by the glacial foreland, where underground transfers took place through complex flow paths. However, the development of a thermokarst drainage network in a portion of the glacial foreland enabled rapid concentrated water transfers that reduced the buffer effect. The glacial foreland was shown to act as a reservoir, storing water during high melt periods and supplying water to downstream compartments during low melt periods. GPR observations revealed the heterogeneity of the internal structure of the glacial foreland, which is composed of a mixture of ice and rock debris mixture, with variable spatial ice content, including massive ice lenses. This heterogeneity may explain the abovementioned hydrological behaviors. Finally, calculation of a partial hydrological budget confirmed the

  8. Is tourism damaging ecosystems in the Andes? Current knowledge and an agenda for future research

    OpenAIRE

    Barros, Agustina; Monz, Christopher; Pickering, Catherine

    2014-01-01

    Despite the popularity of tourism and recreation in the Andes in South America and the regions conservation value, there is limited research on the ecological impacts of these types of anthropogenic use. Using a systematic quantitative literature review method, we found 47 recreation ecology studies from the Andes, 25 of which used an experimental design. Most of these were from the Southern Andes in Argentina (13 studies) or Chile (eight studies) with only four studies from the Northern Ande...

  9. Evolución tectónica, paleogeográfica y metalogénica durante el Cenozoico en los Andes de Chile norte y central e implicaciones para las regiones adyacentes de Bolivia y Argentina Tectonic, paleogeographic, and metallogenic evolution during the Cenozoic in the Andes of Central and Northern Chile and implication for the adjacent regions of Bolivia and Argentina

    OpenAIRE

    Reynaldo Charrier; Marcelo Farías; Víctor Maksaev

    2009-01-01

    La orogenia incaica dio origen a un importante relieve en el Eoceno Medio, el que se concentró en el ámbito del arco magmático precedente, la Cordillera Incaica. Este relieve positivo de orientación NNE se extendió desde el sur de Perú hasta la región central de Chile y separó dos dominios paleogeográficos que tuvieron evoluciones diferentes durante el resto del Cenozoico. El dominio occidental se caracterizó por el predominio de procesos de erosión y sedimentación. En el dominio oriental tam...

  10. Depositación atmosférica de nitrógeno en un transecto valle longitudinal-cordillera de Los Andes, centro-sur de Chile Atmospheric deposition of nitrogen in a transect from the Central Valley to Cordillera de Los Andes, south-central Chile

    OpenAIRE

    Oyarzún, Carlos E; ROBERTO GODOY; SERGIO LEIVA

    2002-01-01

    El aumento de las actividades agrícolas y ganaderas en el centro-sur de Chile puede producir elevadas emisiones de nitrógeno hacia la atmósfera (mayormente NH3). El amoniaco es transportado por corrientes de aire y depositado en el suelo y vegetación. El presente estudio evalúa la depositación atmosférica de compuestos nitrogenados (NO3- y NH4+) en la química de las precipitaciones en un transecto altitudinal de 66 km, desde los alrededores de la ciudad de Osorno (40º 35' S, 72º 57' O, 55 m d...

  11. Peat-bog accumulation rate in the Andes of Tierra del Fuego and Patagonia (Argentina and Chile) during the last 43,000 years

    Energy Technology Data Exchange (ETDEWEB)

    Rabassa, J.; Heusser, C.J.; Coronato, A. (CADIC-CONICET, Ushuaia (Argentina))

    1989-01-01

    Profiles of biogenic deposits formed in peat-bogs and lakes of Tierra del Fuego and Patagonia have been analysed in order to ascertain their internal structure and the accumulation rate of organic matter. This rate, estimated between 0.5 y 0.7 mm/yr for the Late Quaternary, reflects, among other factors, climatic changes and the compaction processes of the sediments. 9 refs., 3 tabs., 3 figs.

  12. Estimation of real evapotranspiration and its variation in Mediterranean landscapes of central-southern Chile

    Science.gov (United States)

    Olivera-Guerra, L.; Mattar, C.; Galleguillos, M.

    2014-05-01

    Evapotranspiration (ETd) is a key controller in the ecohydrological processes of semi-arid landscapes. This is the case of the dry land in Chile's central-southern zone, where forestry, farming and livestock activities must adapt to precipitation with considerable year-on-year variations. In this study, the spatial distribution of ETd was estimated in relation to the land use map and physical parameters of the soil. The ETd was estimated through the Simplified Surface Energy Balance Index (S-SEBI) using data from weather stations and remote data provided by the ASTER and MODIS sensors for November 2004 and 2006, respectively. The spatial variability of ETd was compared among different plant types, soil textural classes and depths using non-parametric statistical tests. In this comparison, the highest rates of ETd were obtained in the forest covers with values of 7.3 ± 0.8 and 8.4 ± 0.8 mm d-1 for 2004 and 2006, respectively. The lowest values were estimated for pastures and shrublands with values of 3.5 ± 1.2 mm d-1 and for crops with rates of 4.4 ± 1.6 mm d-1. Comparison of the ETd of the native forest covers and plantations of exotic species showed statistically significant differences; however, no great variation was noted, at least in the study months. Additionally, the highest rates of ETd were found in the clay loam textures (6.0 ± 1.8 and 6.4 ± 2.0 mm d-1) and the lowest rates in the sandy loam soils (3.7 ± 1.6 and 3.9 ± 1.6 mm d-1) for 2004 and 2006, respectively. The results enable analysis of the spatial patterns of the landscape in terms of the relation between water consumption, ET and the biophysical characteristics of a Mediterranean ecosystem. These results form part of the creation of tools useful in the optimization of decision-making for the management and planning of water resources and soil use in territories with few measuring instruments.

  13. Estimating the Impact of Placing Top University Graduates in Vulnerable Schools in Chile

    OpenAIRE

    Mariana Alfonso; Ana Santiago; Marina Bassi

    2010-01-01

    Enseña Chile (ECh) is one model in the direction of helping close the achievement gap between low-income and high-income students in Chile, and is a first adaptation of the Teach for America (TFA) model in Latin America. This paper provides the first evidence on the impact of the implementation, and is the first evaluation of Teach For America model to shed light on how it affects non-cognitive skills. While it is still premature to speculate the full effect of ECh corps members on student ac...

  14. Evolución tectónica, paleogeográfica y metalogénica durante el Cenozoico en los Andes de Chile norte y central e implicaciones para las regiones adyacentes de Bolivia y Argentina Tectonic, paleogeographic, and metallogenic evolution during the Cenozoic in the Andes of Central and Northern Chile and implication for the adjacent regions of Bolivia and Argentina

    Directory of Open Access Journals (Sweden)

    Reynaldo Charrier

    2009-10-01

    Full Text Available La orogenia incaica dio origen a un importante relieve en el Eoceno Medio, el que se concentró en el ámbito del arco magmático precedente, la Cordillera Incaica. Este relieve positivo de orientación NNE se extendió desde el sur de Perú hasta la región central de Chile y separó dos dominios paleogeográficos que tuvieron evoluciones diferentes durante el resto del Cenozoico. El dominio occidental se caracterizó por el predominio de procesos de erosión y sedimentación. En el dominio oriental también existieron importantes episodios de erosión que originaron depósitos que se encuentran en la vertiente oriental de la cadena en la actualidad y presentan una cronología comparable con la de los depósitos del dominio occidental. Sin embargo, la evolución se caracterizó por presentar, a partir del Eoceno Tardío, diferencias al norte y sur de los ~27ºS. Al norte de esa latitud, en el ámbito del Altiplano-Puna, el arco magmático se mantuvo aproximadamente en la misma posición, coincidente con la del arco actual, y estuvo bordeado por una cuenca de antepaís de retroarco; mientras que, al sur de ~27ºS, se desarrollaron sucesivos arcos magmáticos con una marcada migración hacia el este. El arco magmático del Eoceno Tardío al Oligoceno Tardío - Mioceno Temprano se caracterizó por el desarrollo de una amplia cuenca extensional de intra-arco, la cuenca de Abanico. En esta cuenca se acumularon hasta 3.000 m de rocas volcánicas, volcaniclásticas y, subordinadamente, sedimentarias. A partir del límite oligoceno-mioceno, tuvo lugar un nuevo evento compresivo a lo largo de todo el orógeno que rejuveneció el núcleo de la Cordillera Incaica e invirtió la cuenca de Abanico permitiendo la generación de abundantes depósitos sintectónicos a ambos lados de los nuevos relieves. El inicio de este evento coincide con la orogenia pehuenche, los pulsos compresivos se mantuvieron hasta el Plioceno Temprano. En el Mioceno Temprano a Medio

  15. Spatial characterization of land surface energy fluxes and uncertainty estimation at the Salar de Atacama, Northern Chile

    Science.gov (United States)

    Kampf, Stephanie K.; Tyler, Scott W.

    2006-02-01

    We use Advanced Spaceborne Thermal Emission and Reflection radiometer (ASTER) data to estimate spatial energy flux and evaporation distributions at the Salar de Atacama, a playa in Northern Chile. Our approach incorporates ASTER surface kinetic temperature, emissivity, and reflectance data, ground-based meteorological measurements, and empirical parameters. Energy flux distributions are estimated using either spatially constant or spatially distributed values of model parameters, with spatially distributed parameters assigned separately to each land cover category in an image classification. We test the sensitivity of energy budget calculations to state variable and parameter values by conducting Monte Carlo simulations for regions with ground energy budget measurements. Results show that assigning spatially distributed model parameters via land cover classifications yields significant improvements to ground and sensible heat flux predictions. Latent heat fluxes cannot, however, be predicted with sufficient accuracy to allow estimation of area-integrated evaporative moisture loss at this low-evaporation playa.

  16. Geodetic observations of megathrust earthquakes and backarc wedge deformation across the central Andes

    Science.gov (United States)

    Weiss, J. R.; Brooks, B. A.; Foster, J. H.; Bevis, M. G.; Echalar, A.; Caccamise, D.; Heck, J. M.

    2014-12-01

    High-precision Global Positioning System (GPS) data offer an opportunity to investigate active orogenic wedges yet surface velocity fields are available for only a few examples worldwide. More observations are needed to link deformation processes across multiple timescales and to better understand strain accumulation and release in active wedge settings. Here we present a new GPS velocity field for the central Andes and the backarc orogenic wedge comprising the southern Subandes of Bolivia (SSA), a region previously thought to be mostly isolated from the plate boundary earthquake cycle. The time span of our observations (2000 to mid-2014) includes two megathrust earthquakes along the Chile trench that affected the SSA. The 2007 Mw 7.7 Tocopilla, Chile earthquake resulted in a regional postseismic decrease in the eastward component of horizontal surface velocities. Preliminary analysis of the deformation field from the April 01 2014 Mw 8.2 Pisagua, Chile earthquake also indicates a postseismic signal extending into the SSA. We create an interseismic velocity field for the SSA by correcting campaign GPS site velocities for the seasonal cycles estimated from continuous GPS site time series. We remove the effects of both megathrust events by estimating coseismic steps and fitting linear and logarithmic functions to the postseismic GPS site motions. The velocity estimates at most locations increase after correcting for the transients. This finding suggests that forces leading to shortening and earthquakes in the backarc wedge are not as temporally consistent as previously considered.

  17. International Uranium Resources Evaluation Project (IUREP) national favourability studies: Chile

    International Nuclear Information System (INIS)

    Chile has an area of 740,760 square kilometers. The capital is Santiago. The country is 4,183 km. long and ranges from 22.5 to about 354 km. in width. Its chief topographic features para]lei each other - the Coastal Range, Andes Mountains and Central Valley. The Coastal Range rises to 2,130 meters in the north, but averages from 610 to 700 meters high generally. The range plunges into the Pacific Ocean far south of Valparaiso and reappears in the southern archipelagic islands. The Andes extend along nearly the entire length of Chile and contain 100 volcanoes. Andean peaks range mostly from 3,000 to 6,700 meters in elevation. In southern Chile the Andes are lower, and contain about a dozen major lakes. The mountains disappear in Chilean Patagonia, but reappear at Cape Horn. The Central Valley lies between the Coastal Range and the Andes, being best defined in the midland region as a 64 to 72 km sloping plain. It is the Chilean heartland with three-quarters of the country's population. Salt basins are found over much of northern Chile in the very arid desert, while the region south of the Gulf of Reloncavi consists of unpopulated islands, fjords, channels and heavily forested mountains. The Strait of Magellan, the Tierra del Fuego archipelago and a flat grassland area make up the extreme southern end of the country. Much of Chile is subject to flash floods, earthquakes, volcanic eruptions, landslides and avalanches. In September 1976 the Comision Chilena de Energia Nuclear (CCEN) was given exclusive rights to negotiate contracts with private companies for the exploration, development and mining of uranium and other radioactive minerals. The new law provides the CCEN with considerable flexibility in the terms of the contracts. Pre-964 owners of uranium deposits may reach agreements with foreign companies to mine the uranium, but since 1964 all uranium has belonged to the state. Uranium produced in the country can only be exported after Chile's needs have been met. The

  18. Off-Shore wind potential estimation along the coast of Chile by using scatterometer and Reanalysis data

    Directory of Open Access Journals (Sweden)

    C. Mattar

    2014-06-01

    Full Text Available This work presents the first offshore wind potential estimation over the coast of Chile using long term data series from “QuikSCAT (V04 wind vectors” and ERA-interim’s wind product between 1999-2009 and 1979-2012, respectively. Weibull and Rayleigh’s distribution were used to adjust the data series from the study period to find the probability density function, mean wind speed, maximum and minimum from each data series adjusted per pixel. Power generation and a capacity factor were estimated for the whole scene using three wind turbine models corresponding to 3.6, 5.0 and 8.0 MW. The images obtained from the data processing were grouped into three different wind power zones named (A located up north, (B in the center and (C down south-center. The mean capacity factors are higher than 20%, moreover B and C areas have an average of 36%. This work shows the high wind power potential to generate electricity by using wind off-shore technologies along the coast of Chile.

  19. Estimates of stress drop and crustal tectonic stress from the 27 February 2010 Maule, Chile, earthquake: Implications for fault strength

    Science.gov (United States)

    Luttrell, K.M.; Tong, X.; Sandwell, D.T.; Brooks, B.A.; Bevis, M.G.

    2011-01-01

    The great 27 February 2010 Mw 8.8 earthquake off the coast of southern Chile ruptured a ???600 km length of subduction zone. In this paper, we make two independent estimates of shear stress in the crust in the region of the Chile earthquake. First, we use a coseismic slip model constrained by geodetic observations from interferometric synthetic aperture radar (InSAR) and GPS to derive a spatially variable estimate of the change in static shear stress along the ruptured fault. Second, we use a static force balance model to constrain the crustal shear stress required to simultaneously support observed fore-arc topography and the stress orientation indicated by the earthquake focal mechanism. This includes the derivation of a semianalytic solution for the stress field exerted by surface and Moho topography loading the crust. We find that the deviatoric stress exerted by topography is minimized in the limit when the crust is considered an incompressible elastic solid, with a Poisson ratio of 0.5, and is independent of Young's modulus. This places a strict lower bound on the critical stress state maintained by the crust supporting plastically deformed accretionary wedge topography. We estimate the coseismic shear stress change from the Maule event ranged from-6 MPa (stress increase) to 17 MPa (stress drop), with a maximum depth-averaged crustal shear-stress drop of 4 MPa. We separately estimate that the plate-driving forces acting in the region, regardless of their exact mechanism, must contribute at least 27 MPa trench-perpendicular compression and 15 MPa trench-parallel compression. This corresponds to a depth-averaged shear stress of at least 7 MPa. The comparable magnitude of these two independent shear stress estimates is consistent with the interpretation that the section of the megathrust fault ruptured in the Maule earthquake is weak, with the seismic cycle relieving much of the total sustained shear stress in the crust. Copyright 2011 by the American

  20. "Un devorador de su propia especie". Violencia, justicia y cultura popular en Santa Rosa de los Andes: las formas de la autoridad a los ojos de un peón de oficio matador, Chile 1805

    OpenAIRE

    Daniel Moreno Bazaes

    2016-01-01

    A través del análisis microhistórico del proceso judicial seguido por las autoridades de la villa de Santa Rosa de Los Andes e intervenido por la Real Audiencia de Santiago contra Juan Francisco Varas, “peón-gañan” de la hacienda de Llay-Llay, responsable de a lo menos seis homicidios y otros tantos crímenes que atentaron contra el orden local y el gobierno civil, se pretende dar cuenta de los pormenores de la organización social en el Valle del Aconcagua a fines del siglo XVIII y durante los...

  1. Is tourism damaging ecosystems in the Andes? Current knowledge and an agenda for future research.

    Science.gov (United States)

    Barros, Agustina; Monz, Christopher; Pickering, Catherine

    2015-03-01

    Despite the popularity of tourism and recreation in the Andes in South America and the regions conservation value, there is limited research on the ecological impacts of these types of anthropogenic use. Using a systematic quantitative literature review method, we found 47 recreation ecology studies from the Andes, 25 of which used an experimental design. Most of these were from the Southern Andes in Argentina (13 studies) or Chile (eight studies) with only four studies from the Northern Andes. These studies documented a range of impacts on vegetation, birds and mammals; including changes in plant species richness, composition and vegetation cover and the tolerance of wildlife of visitor use. There was little research on the impacts of visitors on soils and aquatic systems and for some ecoregions in the Andes. We identify research priorities across the region that will enhance management strategies to minimise visitor impacts in Andean ecosystems. PMID:25201299

  2. Andes 1997 Gravity Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Central Andes gravity data (6,151 records) were compiled by Professor Gotze and the MIGRA Group. This data base was received in April, 1997. Principal gravity...

  3. History of Lake Andes

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Information about the history and management of Lake Andes is compiled in this report. It is intended to help future refuge managers become acquainted with the...

  4. Estimation of Damaged Areas due to the 2010 Chile Earthquake and Tsunami Using SAR Imagery of Alos/palsar

    Science.gov (United States)

    Made, Pertiwi Jaya Ni; Miura, Fusanori; Besse Rimba, A.

    2016-06-01

    A large-scale earthquake and tsunami affect thousands of people and cause serious damages worldwide every year. Quick observation of the disaster damage is extremely important for planning effective rescue operations. In the past, acquiring damage information was limited to only field surveys or using aerial photographs. In the last decade, space-borne images were used in many disaster researches, such as tsunami damage detection. In this study, SAR data of ALOS/PALSAR satellite images were used to estimate tsunami damage in the form of inundation areas in Talcahuano, the area near the epicentre of the 2010 Chile earthquake. The image processing consisted of three stages, i.e. pre-processing, analysis processing, and post-processing. It was conducted using multi-temporal images before and after the disaster. In the analysis processing, inundation areas were extracted through the masking processing. It consisted of water masking using a high-resolution optical image of ALOS/AVNIR-2 and elevation masking which built upon the inundation height using DEM image of ASTER-GDEM. The area result was 8.77 Km2. It showed a good result and corresponded to the inundation map of Talcahuano. Future study in another area is needed in order to strengthen the estimation processing method.

  5. Evolución tectónica, paleogeográfica y metalogénica durante el Cenozoico en los Andes de Chile norte y central e implicaciones para las regiones adyacentes de Bolivia y Argentina

    OpenAIRE

    2009-01-01

    La orogenia incaica dio origen a un importante relieve en el Eoceno Medio, el que se concentró en el ámbito del arco magmático precedente, la Cordillera Incaica. Este relieve positivo de orientación NNE se extendió desde el sur de Perú hasta la región central de Chile y separó dos dominios paleogeográficos que tuvieron evoluciones diferentes durante el resto del Cenozoico. El dominio occidental se caracterizó por el predominio de procesos de erosión y sedimentación. En el dominio oriental tam...

  6. The low-grade Canal de las Montañas Shear Zone and its role in the tectonic emplacement of the Sarmiento Ophiolitic Complex and Late Cretaceous Patagonian Andes orogeny, Chile

    Science.gov (United States)

    Calderón, M.; Fosdick, J. C.; Warren, C.; Massonne, H.-J.; Fanning, C. M.; Cury, L. Fadel; Schwanethal, J.; Fonseca, P. E.; Galaz, G.; Gaytán, D.; Hervé, F.

    2012-02-01

    The Canal de las Montañas Shear Zone (CMSZ), southern Patagonian Andes (51-52°S), is a low-grade mylonite belt generated from felsic ignimbritic, pelitic and basaltic protoliths of the Late Jurassic-Early Cretaceous Rocas Verdes basin. The different types of rock fabrics across the CMSZ are thought to be associated with relatively intermediate and high strain conditions, characterized by the development of a narrow western belt of S-Ć-type mylonites and phyllonites interpreted as the metamorphic sole thrust of the Sarmiento Ophiolitic Complex. Highly strained rocks of the CMSZ display a reverse, continent-ward tectonic transport, with a minor dextral component of shearing. Transitional pumpellyite-actinolite and upper greenschist facies metamorphic conditions at ca. 5-6 kbar and 230-260 °C indicate that the primary shearing event occurred in a subduction zone setting. In-situ 40Ar/39Ar laserprobe chronology yielded ages of ca. 85 Ma on syntectonic phengite which are interpreted as representing cooling synchronous with mica crystallization during the main compressive deformational event. The 78-81 Ma U-Pb zircon crystallization ages of cross-cutting plutonic and hypabyssal rocks and 40Ar/39Ar amphibole age of ca.79 Ma from lamprophyric dikes within the fold-thrust belt constrain an upper age limit of the ophiolite tectonic emplacement deformation.

  7. Active tectonics of the Andes

    Science.gov (United States)

    Dewey, J. F.; Lamb, S. H.

    1992-04-01

    Nearly 90 mm a -1 of relative plate convergence is absorbed in the Andean plate-boundary zone. The pattern of active tectonics shows remarkable variations in the way in which the plate slip vector is partitioned into displacement and strain and the ways in which compatibility between different segments is solved. Along any traverse across the plate-boundary zone, the sum of relative velocities between points must equal the relative plate motion. We have developed a kinematic synthesis of displacement and strain partitioning in the Andes from 47°S to 5°N relevant for the last 5 Ma based upon: (1) relative plate motion deduced from oceanic circuits giving a roughly constant azimuth between 075 and 080; (2) moment tensor solutions for over 120 crustal earthquakes since 1960; (3) structural studies of deformed Plio-Pleistocene rocks; (4) topographic/geomorphic studies; (5) palaeomagnetic data; and (6) geodetic data. We recognize four neotectonic zones, with subzones and boundary transfer zones, that are partitioned in different ways. These zones are not coincident with the 'classic' zones defined by the presence or absence of a volcanic chain or differences in finite displacements and strains and tectonic form; the long-term segmentation and finite evolution of the Andes may not occur in constantly defined segments in space and time. In Segment 1 (47°-39°S), the slip vector is partitioned into roughly orthogonal Benioff Zone slip with large magnitude/large slip-surface earthquakes and both distributed dextral shear giving clockwise rotations of up to 50° and dextral slip in the curved Liquine-Ofqui Fault System giving 5°-10° of anticlockwise fore-arc rotation. In Segment 2 (39°-20°S), the slip vector is partitioned into Benioff Zone slip roughly parallel with the slip vector, Andean crustal shortening and a very small component of dextral slip, including that on the Atacama Fault System. Between 39° and 34°S, a cross-strike dextral transfer, which deflects

  8. New time constraints for the age of metamorphism at the ancestral Pacific Gondwana margin of southern Chile (42-52°S)

    OpenAIRE

    Stuart N. Thomson; Francisco Hervé

    2002-01-01

    Fission-track (FT) analysis was performed on ten samples of detrital zircons from several pre-Late Jurassic metamorphic accretionary complexes at the ancestral Pacific margin of Gondwana in southern Chile (42-52°S) previously dated by U-Pb SHRIMP. Post-metamorphic zircon FT cooling ages combined with published U-Pb provenance ages allow the estimation of the following maximum and minimum ages of deposition and metamorphism: the Eastern Andes metamorphic complex (EAMC), 364 to 250 Ma (Late Dev...

  9. Evolución tectónica, paleogeográfica y metalogénica durante el Cenozoico en los Andes de Chile norte y central e implicaciones para las regiones adyacentes de Bolivia y Argentina

    Directory of Open Access Journals (Sweden)

    Reynaldo Charrier

    2009-10-01

    Full Text Available La orogenia incaica dio origen a un importante relieve en el Eoceno Medio, el que se concentró en el ámbito del arco magmático precedente, la Cordillera Incaica. Este relieve positivo de orientación NNE se extendió desde el sur de Perú hasta la región central de Chile y separó dos dominios paleogeográficos que tuvieron evoluciones diferentes durante el resto del Cenozoico. El dominio occidental se caracterizó por el predominio de procesos de erosión y sedimentación. En el dominio oriental también existieron importantes episodios de erosión que originaron depósitos que se encuentran en la vertiente oriental de la cadena en la actualidad y presentan una cronología comparable con la de los depósitos del dominio occidental. Sin embargo, la evolución se caracterizó por presentar, a partir del Eoceno Tardío, diferencias al norte y sur de los ~27ºS. Al norte de esa latitud, en el ámbito del Altiplano-Puna, el arco magmático se mantuvo aproximadamente en la misma posición, coincidente con la del arco actual, y estuvo bordeado por una cuenca de antepaís de retroarco; mientras que, al sur de ~27ºS, se desarrollaron sucesivos arcos magmáticos con una marcada migración hacia el este. El arco magmático del Eoceno Tardío al Oligoceno Tardío - Mioceno Temprano se caracterizó por el desarrollo de una amplia cuenca extensional de intra-arco, la cuenca de Abanico. En esta cuenca se acumularon hasta 3.000 m de rocas volcánicas, volcaniclásticas y, subordinadamente, sedimentarias. A partir del límite oligoceno-mioceno, tuvo lugar un nuevo evento compresivo a lo largo de todo el orógeno que rejuveneció el núcleo de la Cordillera Incaica e invirtió la cuenca de Abanico permitiendo la generación de abundantes depósitos sintectónicos a ambos lados de los nuevos relieves. El inicio de este evento coincide con la orogenia pehuenche, los pulsos compresivos se mantuvieron hasta el Plioceno Temprano. En el Mioceno Temprano a Medio

  10. Copper Bioleaching in Chile

    Directory of Open Access Journals (Sweden)

    Juan Carlos Gentina

    2016-03-01

    Full Text Available Chile has a great tradition of producing and exporting copper. Over the last several decades, it has become the first producer on an international level. Its copper reserves are also the most important on the planet. However, after years of mineral exploitation, the ease of extracting copper oxides and ore copper content has diminished. To keep the production level high, the introduction of new technologies has become necessary. One that has been successful is bioleaching. Chile had the first commercial operation in the world exclusively via bioleaching copper sulfides. Nowadays, all bioleaching operations run in the country contribute to an estimated 10% of total copper production. This article presents antecedents that have contributed to the development of copper bioleaching in Chile.

  11. Use of 137Cs to estimate tillage- and water-induced soil redistribution rates on agricultural land under different use and management in central-south Chile

    International Nuclear Information System (INIS)

    The purpose of this research was to evaluate the applicability of conventional 137Cs sampling and a simplified approach, for estimating medium-term tillage- and water-induced soil erosion and sedimentation rates on agricultural land in Chile. For this purpose, four study sites under contrasting land use and management were selected in central-south Chile. First, a conventional 137Cs approach, based on grid sampling was applied, adapting a mass balance conversion model incorporating soil movement by tillage to the site specific conditions of the study region. Secondly, using the same conversion model, the feasibility of estimating soil redistribution rates from measurements of 137Cs inventories based on composite soil samples taken along contour lines was also tested at all four sites. The redistribution rates associated with tillage and water and the total rates estimated using both methods correlated strongly at all four sites. The conventional method provides more detailed information concerning the redistribution processes operating over the landscape. The simplified method is suitable for assessing soil loss and sediment accumulation in areas exhibiting simple topography and almost similar slopes along the contour lines. Under these conditions, this method permits faster estimation of soil redistribution rates, providing the possibility of estimating soil redistribution rates over larger areas in a shorter time. In order to optimise the costs and benefits of the methods, the sampling and inventory quantification strategy must be selected according to the resolution of the required information, and the scale and complexity of the landscape relief. Higher tillage- and water-induced erosion rates were observed in the annually ploughed cropland sites than in the semi-permanent grassland sites. Subsistence managed crop and grassland sites also show greater erosion effects than the commercially managed sites. The 137Cs methods used permit discrimination between

  12. Preliminary re-evaluation of probabilistic seismic hazard assessment in Chile: from Arica to Taitao Peninsula

    Directory of Open Access Journals (Sweden)

    F. Leyton

    2009-12-01

    Full Text Available Chile is one of the most seismically active countries in the world; indeed, having witnessed very large earthquakes associated with high horizontal peak ground accelerations, the use of probabilistic hazard assessment is an important tool in any decision-making. In the present study, we review all the available information to improve the estimation of the probabilistic seismic hazard caused by two main sources: shallow interplate, thrust earthquakes and intermediate depth, intraplate earthquakes. Using previously defined seismic zones, we compute Gutenberg-Richter laws and, along with appropriate attenuation laws, revaluate the probabilistic seismic hazard assessments in Chile. We obtain expected horizontal peak ground acceleration with a 10% of probability of being exceeded in 50 years, reaching from 0.6 g up 1.0 g in the coast and between 0.4 g and 0.6 g towards the Andes Mountains, with larger values in Northern part of the country. The present study improves our knowledge of geological hazards in Chile, enabling the mitigation of important human and material losses due to large earthquakes in the future.

  13. Mujeres de los Andes

    OpenAIRE

    Arango, Luz Gabriela; Arizabaleta de García, María Teresa; Bejarano, Nilse; Borchart de Moreno, Christiana; Bucheli, Rocío Vaca; Cervantes, Elvira Llanos; Cisneros, Tatiana; Defossez, Anne-Claire; Fassin, Didier; Giraldo, Fernando Urrea; Li, Dina; Malaver, José; Montúfar, Verónica; Moscoso, Martha; Ortega, Diego Zapata

    2016-01-01

    El Seminario "Mujeres De Los Andes: Condiciones De Vida Y Salud" tuvo lugar en la ciudad de Quito, del 6 al 10 de junio de 1991. Reunió investigadores de distintas disciplinas académicas y actores de variados campos, de cuatro países del área andina-Bolivia, Colombia, Ecuador y Perú-, en los cuales está presente el Instituto Francés de Estudios Andinos, principal instigador del evento. Este libro, que reúne la mayor parte de las ponencias en él presentadas, se inscribe en la línea de las corr...

  14. Scale Economies Estimation in the Pork Meat Industry in Chile Estimación de Economías de Escala en la Industria de la Carne de Cerdo en Chile

    Directory of Open Access Journals (Sweden)

    Ricardo Marchant S

    2007-09-01

    Full Text Available The pork meat industry in Chile exhibits significant rates of production growth, with a decreasing trend in the wholesale market price and growing levels of concentration of the supply in a reduced number of companies. The structural element that sustains concentration and expansion of the production is the presence of increasing returns to scale in the production process. This investigation had the objective to verify the presence of economies of scale in this industry. Using a Cobb-Douglas cost function and the assumption of maximization of the benefits of the company in imperfect competition markets, an econometric model was estimated, that allowed considering indirectly the coefficients of the function of underlying production. One was that for the period 1975-2005, the industry presented increasing returns to scale, with an elasticity product-scale of 1.23 and economies of scale, with elasticity cost-production of 0.81. It was concluded that this industry shows conditions to increase its advantage in costs and of expanding its competitiveness in international markets.La industria de la carne de cerdo en Chile exhibe tasas significativas de crecimiento de la producción, acompañada por una tendencia decreciente en el precio a nivel de mercado mayorista, y por niveles crecientes de concentración de la oferta en un número reducido de empresas. El elemento estructural que sustenta la concentración y expansión de la producción es la presencia de rendimientos a escala crecientes en el proceso de producción. Esta investigación tuvo por objetivo verificar la presencia de economías de escala en esta industria. Utilizando una función de costos Cobb-Douglas y el supuesto de maximización de beneficios en una empresa en competencia imperfecta, se estimó un modelo econométrico que permitió estimar indirectamente los coeficientes de la función de producción subyacente. Se encontró que para el período 1975-2005, la industria present

  15. LANDSAT imagery of the Central Andes

    Science.gov (United States)

    Komer, C. A.; Morgan, P.

    1986-01-01

    The central Andes of South America extend from approximately 14 deg. S to 28 deg. S as an unbroken chain of mountains and volcanoes over 2000 km long. It is here that the Nazca plate dives under the South American plate at angles varying from 10 deg to 30 deg. Very little is known about the volcanoes comprising this classic, subduction-type plate margin. A catalogue of the volcanoes in the central Andes is being prepared by Dr. P.W. Francis and Dr. C.A. Wood at the NASA Lunar and Planetary Institute. At present, more than 800 volcanoes of Cenozoic age have been recognized in the chain, with an estimated 75-80 major, active Quarternary volcanoes. Approximately one hundred 1536 x 1536 pixel color composite Optronics positives were produced from six full LANDSAT Thermatic Mapper scenes and three partial TM scenes. These positives cover a large portion of the central Andes. The positives were produced from LANDSAT data using the VAX imaging package, LIPS. The scenes were first transferred from magnetic tape to disk. The LIPS package was then used to select volcanically interesting areas which were then electronically enhanced. Finally, the selected areas were transferred back to tape and printed on the Optronics equipment. The pictures are color composites using LANDSAT TM bands 7,4, and 2 in the red, green, and blue filters, respectively.

  16. A Regional GIS of the Central Andes, South America - Integration of Satellite and Geophysical Data Sets

    OpenAIRE

    Hofmann, K; F. K. List;  

    1996-01-01

    The Central Andes of northern Chile, southwestern Bolivia and northwestern Argentina are studied by a research project supported by the Deutsche Forschungsgemeinschaft (SFB 267). The main topics of these geological and geophysical investigations are the orogeny of the Andean mountains and the crustal development at an active continental margin. The "Andean GIS" is designed as a tool for data collection, management, overview, analysis and mapping. The integration of different data supports the...

  17. An InSAR-based survey of volcanic deformation in the central Andes

    OpenAIRE

    M. E. Pritchard; Simons, M.

    2004-01-01

    We extend an earlier interferometric synthetic aperture radar (InSAR) survey covering about 900 remote volcanos of the central Andes (14°–27°S) between the years 1992 and 2002. Our survey reveals broad (10s of km), roughly axisymmetric deformation at 4 volcanic centers: two stratovolcanoes are inflating (Uturuncu, Bolivia, and Hualca Hualca, Peru); another source of inflation on the border between Chile and Argentina is not obviously associated with a volcanic edifice (here called Lazufre); a...

  18. A cross sectional observational study to estimate herd level risk factors for Leptospira spp. serovars in small holder dairy cattle farms in southern Chile

    OpenAIRE

    Salgado, Miguel; Otto, Barbara; Sandoval, Errol; Reinhardt, German; Boqvist, Sofia

    2014-01-01

    Background The south of Chile constitutes the main cattle milk producing area of the country. Regarding leptospirosis control in Chile, there is neither an official program nor an epidemiological characterization of smallholder dairy farms. This study was carried out to determine Leptospira seroprevalence and to evaluate risk factors associated with seropositivity at herd level in smallholder bovine dairy herds in southern Chile. A cross-sectional study was conducted, and a convenient sample ...

  19. 77 FR 65574 - Lake Andes National Wildlife Refuge Complex, Lake Andes, SD; Draft Comprehensive Conservation...

    Science.gov (United States)

    2012-10-29

    ... Complex. We started this process through a notice in the Federal Register (72 FR 27328; May, 15, 2007... Fish and Wildlife Service Lake Andes National Wildlife Refuge Complex, Lake Andes, SD; Draft... assessment (EA) for the Lake Andes National Wildlife Refuge Complex (Complex), which includes Lake Andes...

  20. Estimation of Arsenic Intake from Drinking Water and Food (Raw and Cooked in a Rural Village of Northern Chile. Urine as a Biomarker of Recent Exposure

    Directory of Open Access Journals (Sweden)

    Oscar Pablo Diaz

    2015-05-01

    Full Text Available The aim of this study was to estimate both the contribution of drinking water and food (raw and cooked to the total (t-As and inorganic (i-As arsenic intake and the exposure of inhabitants of Socaire, a rural village in Chile´s Antofagasta Region, by using urine as biomarker. The i-As intake from food and water was estimated using samples collected between November 2008 and September 2009. A 24-hour dietary recall questionnaire was given to 20 participants. Drinking water, food (raw and cooked and urine samples were collected directly from the homes where the interviewees lived. The percentage of i-As/t-As in the drinking water that contributed to the total intake was variable (26.8–92.9. Cereals and vegetables are the food groups that contain higher concentrations of i-As. All of the participants interviewed exceeded the reference intake FAO/OMS (149.8 µg∙i-As·day−1 by approximately nine times. The concentration of t-As in urine in each individual ranged from 78 to 459 ng·mL−1. Estimated As intake from drinking water and food was not associated with total urinary As concentration. The results show that both drinking water and food substantially contribute to i-As intake and an increased exposure risk to adult residents in contaminated areas.

  1. Near-field tsunami forecast system based on near real-time seismic moment tensor estimation in the regions of Indonesia, the Philippines, and Chile

    Science.gov (United States)

    Inazu, Daisuke; Pulido, Nelson; Fukuyama, Eiichi; Saito, Tatsuhiko; Senda, Jouji; Kumagai, Hiroyuki

    2016-05-01

    We have developed a near-field tsunami forecast system based on an automatic centroid moment tensor (CMT) estimation using regional broadband seismic observation networks in the regions of Indonesia, the Philippines, and Chile. The automatic procedure of the CMT estimation has been implemented to estimate tsunamigenic earthquakes. A tsunami propagation simulation model is used for the forecast and hindcast. A rectangular fault model based on the estimated CMT is employed to represent the initial condition of tsunami height. The forecast system considers uncertainties due to two possible fault planes and two possible scaling laws and thus shows four possible scenarios with these associated uncertainties for each estimated CMT. The system requires approximately 15 min to estimate the CMT after the occurrence of an earthquake and approximately another 15 min to make the tsunami forecast results including the maximum tsunami height and its arrival time at the epicentral region and near-field coasts available. The retrospectively forecasted tsunamis were evaluated by the deep-sea pressure and tide gauge observations, for the past eight tsunamis ( M w 7.5-8.6) that occurred throughout the regional seismic networks. The forecasts ranged from half to double the amplitudes of the deep-sea pressure observations and ranged mostly within the same order of magnitude as the maximum heights of the tide gauge observations. It was found that the forecast uncertainties increased for greater earthquakes (e.g., M w > 8) because the tsunami source was no longer approximated as a point source for such earthquakes. The forecast results for the coasts nearest to the epicenter should be carefully used because the coasts often experience the highest tsunamis with the shortest arrival time (e.g., <30 min).

  2. Soil erosion and sedimentation rates in a small eutrophic lake in southern Chile estimated by 210Pb isotope analysis

    International Nuclear Information System (INIS)

    The purpose of this research is to study the effects of historical land use patterns on soil erosion within the San Pedro Lake watershed (Concepcion, VIII Region, Chile). To this end, a geochronological reconstruction of the last 50 years was accomplished by 210Pb isotope and photo-interpretation analysis through the use of GIS. The erosion rate has varied from 0.40 t ha-1 y-1 in 1955 to 0.86 t ha-1 y-1 in 1994. The decrease in native forest was closely coupled with the increase in exotic forestry. The Total Change, meaning the land use change without considering each typology, shows a constant trend indicating a greater degree of anthropogenic intervention. As opposed to the expected, there is no relationship between land use typologies and erosion rates, however it is possible to recognise some degree of dependency between Total Change and erosion values. It is concluded that over the last 50 years the soil erosion processes in the San Pedro Lake watershed may have been more regulated more by land use changes than by land use typologies themselves. (author)

  3. Hidatidosis humana en Chile. Seroprevalencia y estimación del número de personas infectadas Human Hydatidosis in Chile. Seroprevalence and an estimate of the number of infected people

    OpenAIRE

    Hugo Schenone; María del Carmen Contreras; Patricia Salinas; Lea Sandoval; Tirza Saavedra; Antonio Rojas

    1999-01-01

    Chile is located in the southwestern border of South America. The country is 4,329 km long and 96-342 wide. From north to south it is divided into five marked different biogeographical zones: deserts, steppes, bushes, forests (cattle raising) and austral (sheep raising). Population (June1999) 15,017,760 (14.6% rural). Human hydatidosis is endemic in Chile. According to Ministry of Health information about 320 cases are registered each year. In order to find out the likely prevalence of human ...

  4. Moho topography in the central Andes and its geodynamic implications

    OpenAIRE

    Xiaohui Yuan; S. V. Sobolev; Rainer Kind

    2002-01-01

    P-to-S converted waves at the continental Moho together with waves multiply reflected between the Earth's surface and the Moho have been used to estimate the Moho depth and average crustal Vp/Vs variations in the central Andes. Our analysis confirms and significantly complements the Moho depth estimates previously obtained from wide-angle seismic studies and receiver functions. The resulting crustal thickness varies from about 35 km in the forearc region to more than 70 km beneath the plateau...

  5. Charles Darwin in the Andes

    Science.gov (United States)

    Bizzo, Nelio; Bizzo, Luis Eduardo Maestrelli

    2006-01-01

    Considering geological time as an important epistemological obstacle to the construction of ideas on biological evolution, a study was carried out on the so-called "Darwin Papers". The conclusion was that Charles Darwin's excursion in the Andes during March-April 1835 was a crucial step in this regard. An expedition was carried out in March-April…

  6. Salar de Atacama basin: A record of compressional tectonics in the central Andes since the mid-Cretaceous

    Science.gov (United States)

    Arriagada, Cesar; Cobbold, Peter R.; Roperch, Pierrick

    2006-02-01

    The Salar de Atacama basin lies in the inner fore arc of northern Chile. Topographically and structurally, it is a first-order feature of the central Andes. The sedimentary fill of the basin constrains the timing and extent of crustal deformation since the mid-Cretaceous. We have studied good exposures along the western edge of the basin and have correlated them with seismic reflection sections and data from an exploration well. Throughout most of its history, the basin developed in a foreland setting, during periods of thin-skinned and thick-skinned thrusting. Growth strata provide evidence for coeval sedimentation and thrust motions during mid-Cretaceous, Paleogene, and Neogene times. Pre-Neogene deformation was significant in the basin and in surounding areas of the early central Andes. Models that attempt to explain the current thickness of the central Andes should consider Late Cretaceous and Paleogene shortening, as well as the more obvious Neogene and Quaternary shortening.

  7. Spatio-temporal variability of snow water equivalent in the extra-tropical Andes Cordillera from distributed energy balance modeling and remotely sensed snow cover

    Science.gov (United States)

    Cornwell, E.; Molotch, N. P.; McPhee, J.

    2016-01-01

    Seasonal snow cover is the primary water source for human use and ecosystems along the extratropical Andes Cordillera. Despite its importance, relatively little research has been devoted to understanding the properties, distribution and variability of this natural resource. This research provides high-resolution (500 m), daily distributed estimates of end-of-winter and spring snow water equivalent over a 152 000 km2 domain that includes the mountainous reaches of central Chile and Argentina. Remotely sensed fractional snow-covered area and other relevant forcings are combined with extrapolated data from meteorological stations and a simplified physically based energy balance model in order to obtain melt-season melt fluxes that are then aggregated to estimate the end-of-winter (or peak) snow water equivalent (SWE). Peak SWE estimates show an overall coefficient of determination R2 of 0.68 and RMSE of 274 mm compared to observations at 12 automatic snow water equivalent sensors distributed across the model domain, with R2 values between 0.32 and 0.88. Regional estimates of peak SWE accumulation show differential patterns strongly modulated by elevation, latitude and position relative to the continental divide. The spatial distribution of peak SWE shows that the 4000-5000 m a.s.l. elevation band is significant for snow accumulation, despite having a smaller surface area than the 3000-4000 m a.s.l. band. On average, maximum snow accumulation is observed in early September in the western Andes, and in early October on the eastern side of the continental divide. The results presented here have the potential of informing applications such as seasonal forecast model assessment and improvement, regional climate model validation, as well as evaluation of observational networks and water resource infrastructure development.

  8. Analysis of geodetic interseismic coupling models to estimate tsunami inundation and runup: a study case of Maule seismic gap, Chile

    Science.gov (United States)

    González-Carrasco, J. F.; Gonzalez, G.; Aránguiz, R.; Catalan, P. A.; Cienfuegos, R.; Urrutia, A.; Shrivastava, M. N.; Yagi, Y.; Moreno, M.

    2015-12-01

    Tsunami inundation maps are a powerful tool to design evacuation plans of coastal communities, additionally can be used as a guide to territorial planning and assessment of structural damages in port facilities and critical infrastructure (Borrero et al., 2003; Barberopoulou et al., 2011; Power et al., 2012; Mueller et al., 2015). The accuracy of inundation estimation is highly correlated with tsunami initial conditions, e.g. seafloor vertical deformation, displaced water volume and potential energy (Bolshakova et al., 2011). Usually, the initial conditions are estimated using homogeneous rupture models based in historical worst-case scenario. However tsunamigenic events occurred in central Chilean continental margin showed a heterogeneous slip distribution of source with patches of high slip, correlated with fully-coupled interseismic zones (Moreno et al., 2012). The main objective of this work is to evaluate the predictive capacity of interseismic coupling models based on geodetic data comparing them with homogeneous fault slip model constructed using scaling laws (Blaser et al., 2010) to estimate inundation and runup in coastal areas. To test our hypothesis we select a seismic gap of Maule, where occurred the last large tsunamigenic earthquake in the chilean subduction zone, using the interseismic coupling models (ISC) proposed by Moreno et al., 2011 and Métois et al., 2013. We generate a slip deficit distribution to build a tsunami source supported by geological information such as slab depth (Hayes et al., 2012), strike, rake and dip (Dziewonski et al., 1981; Ekström et al., 2012) to model tsunami generation, propagation and shoreline impact using Neowave 2D (Yamazaki et al., 2009). We compare the tsunami scenario of Mw 8.8, Maule based in coseismic slip distribution proposed by Moreno et al., 2012 with homogeneous and heterogeneous models to identify the accuracy of our results with sea level time series and regional runup data (Figure 1). The estimation of

  9. Estimating the heterogeneous relationship between peer drinking and youth alcohol consumption in Chile using propensity score stratification.

    Science.gov (United States)

    Han, Yoonsun; Grogan-Kaylor, Andrew; Delva, Jorge; Xie, Yu

    2014-11-01

    When estimating the association between peer and youth alcohol consumption, it is critical to account for possible differential levels of response to peer socialization processes across youth, in addition to variability in individual, family, and social factors. Failure to account for intrinsic differences in youth's response to peers may pose a threat of selection bias. To address this issue, we used a propensity score stratification method to examine whether the size of the association between peer and youth drinking is contingent upon differential predicted probabilities of associating with alcohol-consuming friends. Analyzing a Chilean youth sample (N = 914) of substance use, we found that youths are susceptible to the detrimental role of peer drinkers, but the harmful relationship with one's own drinking behavior may be exacerbated among youth who already have a high probability of socializing with peers who drink. In other words, computing a single weighted-average estimate for peer drinking would have underestimated the detrimental role of peers, particularly among at-risk youths, and overestimated the role of drinking peers among youths who are less susceptible to peer socialization processes. Heterogeneous patterns in the association between peer and youth drinking may shed light on social policies that target at-risk youths. PMID:25407422

  10. Estimating the Heterogeneous Relationship between Peer Drinking and Youth Alcohol Consumption in Chile Using Propensity Score Stratification

    Directory of Open Access Journals (Sweden)

    Yoonsun Han

    2014-11-01

    Full Text Available When estimating the association between peer and youth alcohol consumption, it is critical to account for possible differential levels of response to peer socialization processes across youth, in addition to variability in individual, family, and social factors. Failure to account for intrinsic differences in youth’s response to peers may pose a threat of selection bias. To address this issue, we used a propensity score stratification method to examine whether the size of the association between peer and youth drinking is contingent upon differential predicted probabilities of associating with alcohol-consuming friends. Analyzing a Chilean youth sample (N = 914 of substance use, we found that youths are susceptible to the detrimental role of peer drinkers, but the harmful relationship with one’s own drinking behavior may be exacerbated among youth who already have a high probability of socializing with peers who drink. In other words, computing a single weighted-average estimate for peer drinking would have underestimated the detrimental role of peers, particularly among at-risk youths, and overestimated the role of drinking peers among youths who are less susceptible to peer socialization processes. Heterogeneous patterns in the association between peer and youth drinking may shed light on social policies that target at-risk youths.

  11. 78 FR 24228 - Lake Andes National Wildlife Refuge Complex, Lake Andes, SD; Final Comprehensive Conservation Plan

    Science.gov (United States)

    2013-04-24

    ... review and comment following the announcement in the Federal Register on October 29, 2012 ] (77 FR 65574... Fish and Wildlife Service Lake Andes National Wildlife Refuge Complex, Lake Andes, SD; Final... conservation plan and finding of no significant impact (FONSI) for the Lake Andes National Wildlife...

  12. Hidatidosis humana en Chile. Seroprevalencia y estimación del número de personas infectadas Human Hydatidosis in Chile. Seroprevalence and an estimate of the number of infected people

    Directory of Open Access Journals (Sweden)

    Hugo Schenone

    1999-07-01

    Full Text Available Chile is located in the southwestern border of South America. The country is 4,329 km long and 96-342 wide. From north to south it is divided into five marked different biogeographical zones: deserts, steppes, bushes, forests (cattle raising and austral (sheep raising. Population (June1999 15,017,760 (14.6% rural. Human hydatidosis is endemic in Chile. According to Ministry of Health information about 320 cases are registered each year. In order to find out the likely prevalence of human hydatidosis in Chile,a series of serosurveys was carried out in 1988-1997 throughout the total country. By using the indirect hemagglutination reaction and ELISA for hydatidosis (tests with good sensibility and specificity 60,790 unselected apparently healthy persons: 41,399 from urban areas (16,428 blood donors, from 13,894 delivering mothers and 11,077 middle grade school children and 19,361 from rural areas - from randomly selected family groupings-were studied. A total individuals 82 (136/100,000 resulted positive: 36 (87/100,000 urban and 46 (241/100,000 rural, being the prevalence higher in rural areas, particularly in the southern austral zone (mean 1068/100,00. These figures agree with those observed in clinical epidemiological studies. In conformity with the present results, in the whole country 17,002 individuals should have hydatidosis: 10,318 urban and 6,784 rural. All these possible infected people, not necessarily should present pathology in the future, as it has been observed in autopsies from unselected individuals, performed at the Medico-Legal Service in Santiago, in whom 71.3% of diagnosed hydatosis with hydatid cysts in many different locations, was an autopsy finding

  13. Diversification of clearwing butterflies with the rise of the Andes

    OpenAIRE

    De-Silva, D. L.; Ellias, M.; Wilmott, K.; Mallet, J; Day, J. J.

    2015-01-01

    Aim Despite the greatest butterfly diversity on Earth occurring in the Neotrop- ical Andes and Amazonia, there is still keen debate about the origins of this exceptional biota. A densely sampled calibrated phylogeny for a widespread butterfly subtribe, Oleriina (Nymphalidae: Ithomiini) was used to estimate the origin, colonization history and diversification of this species-rich group. Location Neotropics. Methods Ancestral elevation and biogeographical ranges were reconstructed using data ge...

  14. Methane fluxes from a wet puna ecosystem in the Peruvian Andes

    Science.gov (United States)

    Jones, Sam; Diem, Torsten; Priscila Huaraca Quispe, Lidia; Quispe Ccahuana, Adan Julian; Meir, Patrick; Arn Teh, Yit

    2014-05-01

    Discrepancies exist between top-down and bottom-up estimates of the tropical South American atmospheric methane budget. This suggests that current source-sink inventories fail to adequately characterise the landscapes of the region. This may be particularly true of Andean environments where very few field observations have been made. The high tropical Andes, between tree and permanent snow-lines, is home to diverse grass, shrub and giant rosette dominated ecosystems known variously from Venezuela to northern Chile and Argentina as paramo, jalca and puna. In humid regions these are characterised by wet, organic-rich mineral soils, peat-forming wetlands and shallow lakes. Such conditions are likely to promote methane production and potentially represent a regionally significant source to the atmosphere that should be considered. We report on methane fluxes from a bunch-grass dominated puna habitat at 3500 m above sea level in south-eastern Peru. Mean annual temperature and precipitation are 11 °C and 2500 mm, respectively. Temperature is aseasonal but experiences considerable diurnal variations with overnight frosting common-place. In contrast, rainfall is intensely episodic and has a pronounced wet season between September and March. Sampling encompassed a range of topographic features, such as grassland on freely draining, gently inclined or steep slopes and depressions containing bogs, over a 3 ha ridge to basin transition. Monthly sampling was carried out between January 2011 and June 2013 to investigate seasonal variability in methane fluxes. Intensive sampling campaigns were conducted to investigate spatial and short-term variations on a daily basis in two nine-day campaigns during wet and dry season. The site was a net source of methane to the atmosphere during the period of study. Methane fluxes were dominated by emissions from bogs, whereas, freely draining grassland exhibited weak source or marginal sink activity. Temporal variations were most notable at

  15. Isotope hydrology in northern Chile

    International Nuclear Information System (INIS)

    Environmental isotope analyses were done on samples from aquifers in the Pampa del Tamarugal and the Salar de Atacama drainage basin in northern Chile. In the Pampa it is possible to delineate individual groundwater bodies on the basis of their 18O and deuterium contents and, in some cases, to relate these to specific recharge areas. A marked displacement from the meteoric water line indicates that river recharge is an important mechanism for groundwater renewal. Groundwater ages appear high at distance from the Andes and much of the water found in the Pampa may have to be treated as a non-renewable resource. The groundwaters, springs and rivers of the Salar de Atacama drainage basin vary between -6.09 and -8.06%. No difference between the different waters can be recognized and an evaporative isotope enrichment indicates that also here river recharge is an important process. Some groundwaters adjacent to the Salar are very salty but 18O and deuterium data show that these waters are not refluxed brines but simply salty freshwater. The 14C contents in groundwaters and springs are very low but their delta13C values are high. It is concluded that this is probably due to the uptake of volcanic CO2. 14C age dating is thus not possible unless the delta13C values of all possible carbon sources can be defined and the geochemical evolution of the groundwaters is better understood. (author)

  16. The High Andean Cordillera of central Argentina and Chile along the Piuquenes Pass-Cordon del Portillo transect: Darwin's pioneering observations compared with modern geology La Alta Cordillera de los Andes del centro de Argentina y Chile a lo largo de la transecta del Paso Piuquenes-Cordón del Portillo: Las observaciones pioneras de Darwin comparadas con la geología moderna

    Directory of Open Access Journals (Sweden)

    Laura Giambiagi

    2009-04-01

    Full Text Available The geological observations made by Darwin in 1835 during his crossing of the Andes from Santiago to Mendoza via the Piuquenes Pass and Cordón del Portillo are compared with the present geological knowledge of the Cordillera Principal and Cordillera Frontal at 33°-34°S. The analysis of the complex stratigraphy of the Cordillera Principal, the imbricated structure of the Aconcagua fold and thrust belt, as well as the stratigraphy and structure of the inter mountain foreland Tunuyán Basin, allows to assess the pioneer observations of Darwin. He recognized the old metamorphic basement and the granitoids and volcanic sequences of late Paleozoic to Triassic age of the Cordillera Frontal, established the Cretaceous age of the marine successions cropping out along the eastern Cordillera Principal and studied the conglomeratic deposits associated with the uplift of the Cordillera in the Alto Tunuyán Basin. Based on the study of clast provenance of the synorogenic deposits of the Alto Tunuyán Basin, Darwin recognized that the Cordillera Frontal was uplifted later than the Cordillera Principal. The present knowledge of this sector of the Andean Cordillera confirms his pioneer observations and show that Darwin was one of the first scientists ever in realizing that in an orogenic system the sequence of uplift and deformation proceeds from hinterland towards foreland, according to a process that is exceptionally well-illustrated along the Piuquenes-Cordón del Portillo transect.Las observaciones geológicas efectuadas por Darwin en 1935 durante su cruce de la Cordillera de Los Andes entre Santiago y Mendoza realizado en 1835 a través de los pasos del Portillo y Piuquenes son examinadas y comparadas con el conocimiento actual existente de las Cordilleras Principal y Frontal entre los 33°-34°S. El análisis de la compleja estratigrafía de la Cordillera Principal, la estructura de las diferentes láminas imbricadas de la faja plegada y corrida del

  17. Quinua in Chile

    OpenAIRE

    Martinez, Enrique A.; Fuentes, Francisco F.; Chia, Eduardo; Namdar-Irani, Mina; Olguin, Pablo; Saa, Constanza; Thomet, Max; Vidal, Alejandra

    2015-01-01

    The biogeography of quinoa (Chenopodium quinua Willd.) provides a comprehensive view of a crop that is relatively minor in Chilean agriculture, despite growing in a large geographical area (18°–47°S). Quinoa’s genetic diversity illustrates that it is a vital crop in the South American Andes region. It was domesticated in various geographical zones, which generated a wide variety of adaptative morphological and environmental features. Specific adaptations in each macrozone throughout the Andes...

  18. Holocene tephra-fall deposits of southern and austral Andes volcanic zones (33-54oS): eruption recurrence

    International Nuclear Information System (INIS)

    Radiometric 14C dating is a very useful tool to study the chronostratigraphy of pyroclastic deposits. In addition, 14C ages are essential parameters for the estimation of the recurrence time of the explosive volcanic activity. The origin, distribution and relative age of mappable Holocene tephra-fall deposits of the Southern Andes Volcanic Zone (SVZ) and Austral Andes Volcanic Zone (AVZ) from 33oS-54oS, were studied and their recurrence period is analysed (au)

  19. Lake Andes National Wildlife Refuge Complex : Lake Andes National Wildlife Refuge, Karl Mundt National Wildlife Refuge, Lake Andes Wetland Management District : 1997 Annual narrative report

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Lake Andes NWR, Karl Mundt NWR, and Lake Andes WMD outlines Refuge accomplishments during the 1997 calendar year. The report begins...

  20. Lake Andes National Wildlife Refuge Complex : Lake Andes National Wildlife Refuge, Karl Mundt National Wildlife Refuge, Lake Andes Wetland Management District : Updated- 2003 annual narrative report

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Lake Andes NWR, Karl Mundt NWR, and Lake Andes WMD outlines Refuge accomplishments during the 2003 calendar year. The report begins...

  1. Lake Andes National Wildlife Refuge Complex : Lake Andes National Wildlife Refuge, Karl Mundt National Wildlife Refuge, Lake Andes Wetland Management District : 1996 Annual narrative report

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Lake Andes NWR, Karl Mundt NWR, and Lake Andes WMD outlines Refuge accomplishments during the 1996 calendar year. The report begins...

  2. Lake Andes National Wildlife Refuge Complex : Lake Andes National Wildlife Refuge, Karl Mundt National Wildlife Refuge, Lake Andes Wetland Management District : 1999 Annual narrative report

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Lake Andes NWR, Karl Mundt NWR, and Lake Andes WMD outlines Refuge accomplishments during the 1999 calendar year. The report begins...

  3. Lake Andes National Wildlife Refuge Complex : Lake Andes National Wildlife Refuge, Karl Mundt National Wildlife Refuge, Lake Andes Wetland Management District : 1994 Annual narrative report

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Lake Andes NWR, Karl Mundt NWR, and Lake Andes WMD outlines Refuge accomplishments during the 1994 calendar year. The report begins...

  4. Lake Andes National Wildlife Refuge Complex : Lake Andes National Wildlife Refuge, Karl Mundt National Wildlife Refuge, Lake Andes Wetland Management District : 1995 Annual narrative report

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Lake Andes NWR, Karl Mundt NWR, and Lake Andes WMD outlines Refuge accomplishments during the 1995 calendar year. The report begins...

  5. Lake Andes National Wildlife Refuge Complex : Lake Andes National Wildlife Refuge, Karl Mundt National Wildlife Refuge, Lake Andes Wetland Management District : 1998 Annual narrative report

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Lake Andes NWR, Karl Mundt NWR, and Lake Andes WMD outlines Refuge accomplishments during the 1998 calendar year. The report begins...

  6. Lake Andes National Wildlife Refuge Complex : Lake Andes National Wildlife Refuge, Karl Mundt National Wildlife Refuge, Lake Andes Wetland Management District : 2000 Annual narrative report

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Lake Andes NWR, Karl Mundt NWR, and Lake Andes WMD outlines Refuge accomplishments during the 2000 calendar year. The report begins...

  7. Potential of a Neutrino Detector in the ANDES Underground Laboratory for Geophysics and Astrophysics of Neutrinos

    CERN Document Server

    Machado, P A N; Nunokawa, H; Funchal, R Zukanovich

    2012-01-01

    The construction of the Agua Negra tunnels that will link Argentina and Chile under the Andes, the world longest mountain range, opens the possibility to build the first deep underground labo- ratory in the Southern Hemisphere. This laboratory has the acronym ANDES (Agua Negra Deep Experiment Site) and its overburden could be as large as \\sim 1.7 km of rock, or 4500 mwe, providing an excellent low background environment to study physics of rare events like the ones induced by neutrinos and/or dark matter. In this paper we investigate the physics potential of a few kiloton size liquid scintillator detector, which could be constructed in the ANDES laboratory as one of its possible scientific programs. In particular, we evaluate the impact of such a detector for the studies of geoneutrinos and galactic supernova neutrinos assuming a fiducial volume of 3 kilotons as a reference size. We emphasize the complementary roles of such a detector to the ones in the Northern Hemisphere neutrino facilities through some adv...

  8. Lake Andes NWR Water Use Report- 1961

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report contains locations and water use at Lake Andes NWR for 1961. Existing water supplies are tabulated for each of the four units providing numbers for...

  9. Lake Andes NWR Water Use Report- 2009

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report contains locations and water use at Lake Andes NWR for 2009. Short forms are supplied for the years water use report management plan. These forms cover...

  10. Lake Andes NWR Water Use Report- 1988

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report contains locations and water use at Lake Andes NWR for 1988. General water uses are discussed for 1988 for each unit, impoundment data is tabulated...

  11. Lake Andes NWR Water Use Report- 2013

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report contains locations and water use at Lake Andes NWR for 2013. Short forms are supplied for the years water use report management plan. These forms cover...

  12. Lake Andes NWR Water Use Report- 1998

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report contains locations and water use at Lake Andes NWR for 1998. General water uses are discussed for 1998 for each unit, impoundment data is tabulated...

  13. Lake Andes NWR Water Use Report- 1964

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report contains locations and water use at Lake Andes NWR for 1964. Existing water supplies are tabulated for each of the four units providing numbers for...

  14. Lake Andes NWR Water Use Report- 1989

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report contains locations and water use at Lake Andes NWR for 1989. General water uses are discussed for 1989 for each unit, impoundment data is tabulated...

  15. Lake Andes NWR Water Use Report- 2006

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report contains locations and water use at Lake Andes NWR for 2006. Short forms are supplied for the years water use report management plan. These forms cover...

  16. Lake Andes NWR Water Use Report- 2000

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report contains locations and water use at Lake Andes NWR for 2000. General water uses are discussed for 2000 for each unit, impoundment data is tabulated...

  17. Lake Andes NWR Water Use Report- 1982

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report contains locations and water use at Lake Andes NWR for 1982. General water uses are discussed for 1982 for each unit, impoundment data is tabulated...

  18. Lake Andes NWR Water Use Report- 1984

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report contains locations and water use at Lake Andes NWR for 1984. General water uses are discussed for 1984 for each unit, impoundment data is tabulated...

  19. Lake Andes NWR Water Use Report- 1966

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report contains locations and water use at Lake Andes NWR for 1966. General water uses are discussed for 1966 for each unit, impoundment data is tabulated...

  20. Lake Andes NWR Water Use Report- 1963

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report contains locations and water use at Lake Andes NWR for 1963. Existing water supplies are tabulated for each of the four units providing numbers for...

  1. Lake Andes NWR Water Use Report- 2008

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report contains locations and water use at Lake Andes NWR for 2008. Short forms are supplied for the years water use report management plan. These forms cover...

  2. Lake Andes NWR Water Use Report- 1959

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report contains locations and water use at Lake Andes NWR for 1959. Appears to just be the correspondence letter to the regional supervisor with some data on...

  3. Lake Andes NWR Water Use Report- 2005

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report contains locations and water use at Lake Andes NWR for 2005. Short forms are supplied for the years water use report management plan. These forms cover...

  4. Lake Andes NWR Water Use Report- 1993

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report contains locations and water use at Lake Andes NWR for 1993. General water uses are discussed for 1993 for each unit, impoundment data is tabulated...

  5. Lake Andes NWR Water Use Report- 1971

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report contains locations and water use at Lake Andes NWR for 1971. General water uses are discussed for 1971 for each unit, impoundment data is tabulated...

  6. Lake Andes NWR Water Use Report- 1965

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report contains locations and water use at Lake Andes NWR for 1965. General water uses are discussed for 1965 for each unit, impoundment data is tabulated...

  7. Lake Andes NWR Water Use Report- 2010

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report contains locations and water use at Lake Andes NWR for 2010. Short forms are supplied for the years water use report management plan. These forms cover...

  8. Lake Andes NWR Water Use Report- 2007

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report contains locations and water use at Lake Andes NWR for 2007. Short forms are supplied for the years water use report management plan. These forms cover...

  9. Lake Andes NWR Water Use Report- 1990

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report contains locations and water use at Lake Andes NWR for 1990. General water uses are discussed for 1990 for each unit, impoundment data is tabulated...

  10. Lake Andes NWR Water Use Report- 1968

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report contains locations and water use at Lake Andes NWR for 1968. General water uses are discussed for 1968 for each unit, impoundment data is tabulated...

  11. Lake Andes NWR Water Use Report- 1970

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report contains locations and water use at Lake Andes NWR for 1970. General water uses are discussed for 1970 for each unit, impoundment data is tabulated...

  12. Lake Andes NWR Water Use Report- 1995

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report contains locations and water use at Lake Andes NWR for 1995. General water uses are discussed for 1995 for each unit, impoundment data is tabulated...

  13. Lake Andes NWR Water Use Report- 1960

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report contains locations and water use at Lake Andes NWR for 1960. A short summary of water rights is provided. Existing water supplies, as of January 1961,...

  14. Lake Andes NWR Water Use Report- 1969

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report contains locations and water use at Lake Andes NWR for 1969. General water uses are discussed for 1969 for each unit, impoundment data is tabulated...

  15. Lake Andes NWR Water Use Report- 1947

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report contains locations and water use at Lake Andes NWR for 1947. It provides a table of each unit along with the crest of spill elevation and a recommended...

  16. Lake Andes NWR Water Use Report- 1991

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report contains locations and water use at Lake Andes NWR for 1991. General water uses are discussed for 1991 for each unit, impoundment data is tabulated...

  17. Lake Andes NWR Water Use Report- 2012

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report contains locations and water use at Lake Andes NWR for 2012. Short forms are supplied for the years water use report management plan. These forms cover...

  18. Lake Andes NWR Water Use Report- 1999

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report contains locations and water use at Lake Andes NWR for 1999. General water uses are discussed for 1999 for each unit, impoundment data is tabulated...

  19. Lake Andes NWR Water Use Report- 1994

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report contains locations and water use at Lake Andes NWR for 1994. General water uses are discussed for 1994 for each unit, impoundment data is tabulated...

  20. Lake Andes NWR Water Use Report- 1983

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report contains locations and water use at Lake Andes NWR for 1983. General water uses are discussed for 1983 for each unit, impoundment data is tabulated...

  1. Lake Andes NWR Water Use Report- 1987

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report contains locations and water use at Lake Andes NWR for 1987. General water uses are discussed for 1987 for each unit, impoundment data is tabulated...

  2. Lake Andes NWR Water Use Report- 2004

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report contains locations and water use at Lake Andes NWR for 2004. Short forms are supplied for the years water use report management plan. These forms cover...

  3. Lake Andes NWR Water Use Report- 1992

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report contains locations and water use at Lake Andes NWR for 1992. General water uses are discussed for 1992 for each unit, impoundment data is tabulated...

  4. Remote sensing and climate data as a key for understanding fasciolosis transmission in the Andes: review and update of an ongoing interdisciplinary project

    OpenAIRE

    Màrius V. Fuentes

    2006-01-01

    Fasciolosis caused by Fasciola hepatica in various South American countries located on the slopes of the Andes has been recognized as an important public health problem. However, the importance of this zoonotic hepatic parasite was neglected until the last decade. Countries such as Peru and Bolivia are considered to be hyperendemic areas for human and animal fasciolosis, and other countries such as Chile, Ecuador, Colombia and Venezuela are also affected. At the beginning of the 1990s a multi...

  5. 3D density model of the Central Andes

    Science.gov (United States)

    Prezzi, Claudia B.; Götze, Hans-Jürgen; Schmidt, Sabine

    2009-12-01

    We developed a 3D density model of the continental crust, the subducted plate and the upper mantle of the Central Andes between 20-29°S and 74-61°W through the forward modelling of Bouguer anomaly. The goal of this contribution is to gain insight on the lithospheric structure integrating the available information (geophysical, geologic, petrologic, and geochemical) in a single model. The geometry of our model is defined and constrained by hypocentre location, reflection and refraction on and offshore seismic lines, travel time and attenuation tomography, receiver function analysis, magnetotelluric studies, thermal models and balanced structural cross-sections. The densities allocated to the different bodies are calculated considering petrologic and geochemical data and pressure and temperature conditions. The model consists of 31 parallel E-W vertical planes, where the continental crust comprises distinct bodies, which represent the different morphotectonic units of the Central Andes. We include a partial melting zone at midcrustal depths under the Altiplano-Puna (low-velocity zone) and consider the presence of a rheologically strong block beneath the Salar de Atacama basin, according to recent seismic studies. Contour maps of the depth of the continental Moho, the thickness of the lower crust and the depth to the bottom of the lithosphere below South America are produced. The possible percentage of partial melt in the Central Andes low-velocity zone is estimated. The residual anomaly is calculated by subtracting from the Bouguer anomaly the gravimetric effect of the modelled subducted slab and of the modelled Moho. Isostatic anomalies are calculated from regional and local isostatic Mohos calculated with and without internal loads, derived from our gravity model, which are then compared to the modelled continental Moho. This study contributes to a more detailed knowledge of the lithospheric structure of this region of the Andes and provides an integrated 3D

  6. Tendencias generales en la toponimia del Norte Grande de Chile

    Directory of Open Access Journals (Sweden)

    Guillermo Latorre

    1997-09-01

    Full Text Available En este trabajo el autor se propone examinar las facetas más salientes de la preponderancia del sustrato indígena en la toponimia mayor del Norte Grande, asunto poco o nada tratado en descripciones del español de Chile. Pasa revista a voces como "Arica", "Chañaral", "Iquique", "Taltal", "Tocopilla", "Chuquicamata", "Andes", "Antofagasta", "Calama", "Pica", "Loa" y otras. Finalmente, da algunas explicaciones de esa marcada presencia de topónimos autóctonos a pesar de cinco siglos de dominio español. (In this paper, the author examines the most salient features of the prevalence of indigenous backgrounds in the toponymy of Northernmost Chile, an aspect barely tackled, or simply neglected, in the descriptions of Chilean Spanish. The author reviews terms such as "Arica", "Chañaral", "Iquique", "Taltal", "Tocopilla", "Chuquicamata", "Andes", "Antofagasta", "Calama", "Pica", "Loa", and others. Also, some explanations are offered that may justify the notorious presence of native placenames, in spite of five centuries of Spanish domination.

  7. Surface control on contrasts in deformation between eastern and western margins of the Central Andes

    Science.gov (United States)

    Schlunegger, F.; Norton, K. P.

    2012-04-01

    enhanced orographic rainfall, which promotes thrusting and internal shortening. A fault-scale coupled erosion-deformation model also shows that low erosion rates and steep topographic angles would have forced a migration of deformation from the Western Escarpment to the eastern side. These findings illustrate the strong control of orographic precipitation on the deformation of the Central Andes. Kober, F. et al. Denudation rates and topography-driven rainfall threshold in northern Chile: multiple cosmogenic nuclide data and sediment budgets. Geomorphology 83, 97-120 (2007). Norton, K. & Schlunegger, F. Migrating deformation in the Central Andes from enhanced orographic rainfall. Nat. Commun. 2, 584 (2011). Safran, E. B et al. Erosion rates driven by channel network incision in the Bolivian Andes. Earth Surf. Process Landforms 30, 1007-1024 (2005).

  8. Glacial recession in the Tropical Andes from the Little Ice Age: the case of Ampato Volcanic Complex (Southern Peru

    Science.gov (United States)

    Alcalá, J.; Palacios, D.; Zamorano, J. J.

    2010-03-01

    Europa (Cordillera Cantábrica, NO de España). Análisis morfológico y reconstrucción del avance glaciar histórico. Rev. C & G., 19 (3-4), 79-94. Hastenrath, S. L. (2009): Past glaciation in the tropics. Quaternary Science Reviews, 28: 790-798. Jomelli, V.; Favier, V.; Rabatel, A.; Brunstein, D.; Hoffmann, G.; and Francou, B. (2009): Fluctuations of glaciers in the tropical Andes over the last millennium and palaeoclimatic implications: A review. Palaeogeography, Palaeoclimatology, Palaeoecology, doi: 10.1016/j.palaeo.2008.10.033. Kaser, G., Osmaston, H.A., 2002. Tropical glaciers. Cambridge University Press, Cambridge. Mark, B. (2008): Tracing tropical Andean glaciers over space and time: Some lessons and transdisciplinary implications. Global and Planetary Change, 60: 101-114. Osmaston, H. (2005): Estimates of glacier equilibrium line altitudes by the Area _ Altitude, the Area _ Altitude Balance Ratio and the Area _ Altitude Balance Index Methods and their validation. Quaternary International, 138-139: 22-31. Rabatel, A., Jomelli, V., Naveau, P., Francou, B., Grancher, D. (2005). Dating of Little Ice Age glacier fluctuations in the tropical Andes: Charquini glaciers, Bolivia, 16ºS. C. R. Geoscience, 337: 1311-1322. Rabatel, A., Francou, B., Jomelli, V., Naveau, P., Grancher, D. (2008). A chronology of the Little Ice Age in the tropical Andes of Bolivia (16º S) and its implications for climate reconstruction. Quaternary Research, 70: 198-212. Ramirez, E., Francou, B., Ribstein, P., Descloitres, M., Guerin, R., Mendoza, J., Gallaire, R., Pouyaud, B., Jordan, E., 2001. Small glaciers disappearing in the tropical Andes: a case study in Bolivia: Glaciar Chacaltaya (16°S). Journal of Glaciology 47 (157), 187-194. Soruco, A.; Vincent, C.; Francou, B.; Ribstein, P.; Berger, T.; Sicart, J. E.; Wagnon, P.; Arnaud, Y.; Favier, V.; and Lejeune, Y. (2009): Mass balance of Glacier Zongo, Bolivia, between 1956 and 2006, using glaciological, hydrological and geodetic methods

  9. Eso's Situation in Chile

    Science.gov (United States)

    1995-02-01

    that the best VLT site would be the Paranal Mountain, 700 km north of La Silla and 130 km south of Antofagasta, the capital of the Second Region in Chile. In October 1988, the Chilean Government by an official act donated the land surrounding Paranal (in all 725 sq. km) to ESO. As is the case for La Silla, this would serve to protect the planned, incredibly sensitive mega-telescope against all possible future sources of outside interference. The donation was made on the condition that ESO would indeed proceed with the construction of the VLT at Paranal within the next five years. The corresponding decision was taken by the ESO Council in December 1990. The construction of the VLT observatory site at Paranal started immediately thereafter, thus fulfilling the condition attached to the donation. The construction of the VLT is now well advanced. In Europe, the main parts of the first VLT unit 8.2-metre telescope will be pre-assembled later this year and the first two of the enormous mirrors are being polished. In Chile, the extensive landscaping of the Paranal peak was finished in 1993, during which around 300,000 cubic metres of rock and soil was removed to provide a 100x100 sq. metres platform for the VLT, and the concrete foundations are now ready. The installation of the first telescope enclosure can now begin and the next will start later this year. The first of the four telescopes is expected to start observations in late 1997. All in all, ESO has until now committed about 70 percent of the expected total investment for the VLT, estimated to be approximately 570 million DEM. THE OWNERSHIP OF PARANAL According to information later received, the Chilean Ministry of National Properties ("Bienes Nacionales") inscribed in 1977 in its name various lands in the commune of Taltal, including the area of the Paranal peak. At that time, i.e. ten years before ESO decided to construct the VLT, nobody in this Organisation could imagine that this telescope would one day be

  10. Fishery Management Plan for Lake Andes National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Lake Andes was a much larger body of water prior to the construction of an artificial outlet structure that lowered the water level by 13 feet. Since Lake Andes is...

  11. Recreational Fishery Management Plan for Lake Andes National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Current condition of lake Andes (1996) and highlights potential problems and recommendations for improving the lake as a hatchery. Lake Andes was a much larger body...

  12. Fish Population Investigation: Lake Andes, Charles Mix County

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Brief background on Lake Andes fishing history, and data on current fish populations. Lake Andes was a much larger body of water prior to the construction of an...

  13. On recent measurements from the Andes Lidar Observatory

    Science.gov (United States)

    Liu, Alan Z.; Snively, Jonathan; Heale, Christopher; Cao, Bing

    2016-07-01

    The Andes Lidar Observatory is an upper atmosphere observatory located in Cerro Pachón, Chile (30.3S, 70.7W). It houses a Na Wind/Temperature Lidar, an all sky airglow imager, a mesospheric temperature mapper, an infrared imager and a meteor radar. This suite of instrumentation provides comprehensive measurements of the mesopause region and enables detailed study of wave dynamics. With the recent upgrade of the Na lidar, many complex dynamic processes were observed and resolved in detail. I will present several intriguing phenomena seen in the lidar measurement from recent campaigns, and a detailed analysis of a complex wave propagation event, which involved a large vertical wind oscillation exceeding 10 m/s. A nonlinear gravity wave model was able to reproduce most of the observed features. The results suggest that the wave experienced partial reflections at two altitudes and a critical layer in between, resulting in large vertical wind amplitude and multi-layer distribution of wave energy.

  14. Fundacion Chile Incubator : Chile Case Study

    OpenAIRE

    World Bank

    2014-01-01

    Foundation Chile was created in 1976 as a nonprofit governed jointly by the Chilean government and a large American conglomerate. It proactively introduces technology innovations and develops companies in target industries including agribusiness, marine resources, forestry, environment and chemical metrology, human capital, and information and communication technologies. Among its successe...

  15. The complete mitochondrial genome of the endemic and threatened killifish Orestias ascotanensis Parenti, 1984 (Cyprinodontiformes, Cyprinodontidae) from the High Andes.

    Science.gov (United States)

    Quezada-Romegialli, Claudio; Guerrero, Claudia Jimena; Véliz, David; Vila, Irma

    2016-07-01

    The killifish Orestias ascotanensis is endemic to the small isolated springs of Ascotán salt pan in the Central High Andes, Chile. Due to small populations, mining activity, and increasing aridity, this species is catalogued in danger of extinction. The complete mitochondrial genome of O. ascotanesis was assembled with an Ion Torrent sequencer (chip 318) that produced 2.61 million of reads. The 16 617 bp of the entire genome consisted of 22 transfer RNAs, 2 ribosomal RNAs, 13 protein-coding genes, and a control region, showing that the gene composition and arrangement match to that reported for most fishes. PMID:26152352

  16. Initiation of the Magallanes foreland basin: Timing of the southernmost Patagonian Andes orogeny revised by detrital zircon provenance analysis

    Science.gov (United States)

    Fildani, A.; Cope, T.D.; Graham, S.A.; Wooden, J.L.

    2003-01-01

    New sensitive high-resolution ion microprobe-reverse geometry U-Pb detrital zircon data establish the timing of onset of foreland basin subsidence in the Magallanes basin and the age of the Patagonian Andes in southernmost Chile. Initiation of the Magallanes foreland basin is signaled by the abrupt occurrence of sandstone of the Punta Barrosa Formation, loosely dated as upper Albian-Cenomanian from biofacies assemblages. Detrital zircon analyses demonstrate that the Punta Barrosa Formation is not older than 92 ?? 1 Ma and that the linked Andean belt started forming in the Turonian.

  17. On the generation of coastal lows in central Chile

    International Nuclear Information System (INIS)

    Previous studies of the coastal-low occurrences in central Chile have been aimed at the formulation of a conceptual model to explain observed features in connection with applied studies. The most prominent weather pattern associated with CL occurrences, (type A), coincides with the onset of a warm, middle-troposphere ridge over central Chile, and a surface high over northern Argentina. The synoptic forcing of the low is related to weak frontal disturbances that travel equatorwards. They result in a thickening of the marine layer that becomes blocked by the coastal escarpment, at the time of the onset of the ridge aloft. The blocking of the stable air above the subsidence inversion by the Andes is also hypothesized. The analysis of the subsidence inversion, the geometry of the coastal and Andes mountain ranges, and a scale analysis of the non-dimensional governing equations for the generation of the coastal lows, following the approach of Reason and Steyn (1990); leads to the conclusion that both blocking actions are strong and persistent in central Chile. An interactive mechanism between the upper and lower blocking effects is postulated to explain the cyclonic vorticity and the initial steering of the coastal lows. The scale analysis of the governing equations for the propagation stage of the low suggests that, departing for the South African case, non-linearity is important here, and that solitary Kelvin waves could be expected. Theoretical phase propagation speeds and Rossby radii are found to range between 8 and 15 m s-1 and 100-250 km, respectively. The importance of strong southerly winds ahead of the low and weak winds at its trailing edge is also stressed, as another major departure from the coastal-low behaviour elsewhere. (author). 17 refs, 4 figs, 4 tabs

  18. Copper Bioleaching in Chile

    OpenAIRE

    Juan Carlos Gentina; Fernando Acevedo

    2016-01-01

    Chile has a great tradition of producing and exporting copper. Over the last several decades, it has become the first producer on an international level. Its copper reserves are also the most important on the planet. However, after years of mineral exploitation, the ease of extracting copper oxides and ore copper content has diminished. To keep the production level high, the introduction of new technologies has become necessary. One that has been successful is bioleaching. Chile had the first...

  19. Marine Energy in Chile

    OpenAIRE

    Antonio Levy

    2012-01-01

    This is the first issue of a new series dedicated to deliver concise information on energy innovation published by the Energy Innovation Center at the IDB. This issue offers a primer on the potential for marine energy in Chile. The ocean is increasingly recognized as a viable source of renewable energy, and Chile, with its long coastline, powerful waves and tidal currents, has captured the attention of marine energy proponents. While harvesting this source of energy would increase sustainabil...

  20. Spatio-temporal variability of snow water equivalent in the extra-tropical Andes cordillera from a distributed energy balance modeling and remotely sensed snow cover

    Science.gov (United States)

    Cornwell, E.; Molotch, N. P.; McPhee, J.

    2015-09-01

    Seasonal snow cover is the primary water resource precursor for human use and environmental sustain along the extratropical Andes Cordillera. Despite its importance, relatively little research has been devoted to understanding the properties, distribution and variability of this natural resource. This research provides high-resolution distributed estimates of end-of-winter and spring snow water equivalent over a 152 000 km2 domain that includes the mountainous reaches of central Chile and Argentina. Remotely sensed fractional snow covered area and other relevant forcings are combined with extrapolated data from meteorological stations and a simplified physically-based energy balance model in order to obtain melt-season peak SWE. Estimates show an overall coefficient of determination R2 of 0.61 compared to observations at 12 automatic snow water equivalent sensors distributed across the model domain, with R2 values between 0.32 and 0.88. Regional estimates of peak SWE accumulation show differential patterns strongly modulated by elevation, latitude and position relative to the continental divide. Average peak SWE increases by nearly 500 mm for every 1000 m in elevation gain for the central and southern sub-regions of the model domain, but this effect is much less pronounced in the northern reaches. The 3000-4000 m a.s.l. elevation band is the most significant accumulation area for most of the northern and central reaches of the domain, although the 4000-5000 m a.s.l. band, despite a smaller contributing area, almost doubles the accumulation amounts estimated for the lower adjacent subdomain. Snow accumulation reaches an earlier peak in the western Andes, and the eastern side of the continental divide shows lower snow accumulation at all elevations except for the southern region represented by the Neuquén River Basin. The results presented here have the potential of informing applications such as seasonal forecast model assessment and improvement, regional climate

  1. Geometric evolution of the Horcones Inferior Glacier (Mount Aconcagua, Central Andes) during the 2002-2006 surge

    Science.gov (United States)

    Pitte, Pierre; Berthier, Etienne; Masiokas, Mariano H.; Cabot, Vincent; Ruiz, Lucas; Ferri Hidalgo, Lidia; Gargantini, Hernán.; Zalazar, Laura

    2016-01-01

    The Central Andes of Chile and Argentina (31-35°S) contain a large number and variety of ice masses, but only two surging glaciers have been studied in this region. We analyzed the 2002-2006 surge of the Horcones Inferior Glacier, Mount Aconcagua, Argentina, based on medium spatial resolution (15-30 m) satellite images and digital elevation models. During the buildup phase the glacier was stagnant, with velocities lower than 0.1 m/d. In the active-phase velocities reached 14 m/d and the glacier front advanced 3.1 km. At the peak of the active phase (2003-2004), the area-averaged elevation change was -42 m in the reservoir zone (2.53 km2) and +30 m in the receiving zone (3.31 km2). The estimated ice flux through a cross section located at 4175 meter above sea level was 108 m3 during a period of 391 days, a flux that suggests a mean glacier thickness at this location of ~90 m. The depletion phase showed a recovery of the reservoir zone elevation, the down wasting of the receiving zone (-17 m, 2007-2014), and a return to quiescent velocities. The short active phase, the abrupt change in the velocities, and the high level of the proglacial stream indicate a hydrological switch (Alaska type) trigger. The 2002-2006 and 1984-1990 surges of Horcones Inferior were synchronous with the surges of nearby Grande del Nevado Glacier. These events occurred after periods of positive mass balance, so we hypothesize a climate driver.

  2. Trends and ENSO/AAO Driven Variability in NDVI Derived Productivity and Phenology alongside the Andes Mountains

    Directory of Open Access Journals (Sweden)

    Francisco J. Meza

    2013-03-01

    Full Text Available Increasing water use and droughts, along with climate variability and land use change, have seriously altered vegetation growth patterns and ecosystem response in several regions alongside the Andes Mountains. Thirty years of the new generation biweekly normalized difference vegetation index (NDVI3g time series data show significant land cover specific trends and variability in annual productivity and land surface phenological response. Productivity is represented by the growing season mean NDVI values (July to June. Arid and semi-arid and sub humid vegetation types (Atacama desert, Chaco and Patagonia across Argentina, northern Chile, northwest Uruguay and southeast Bolivia show negative trends in productivity, while some temperate forest and agricultural areas in Chile and sub humid and humid areas in Brazil, Bolivia and Peru show positive trends in productivity. The start (SOS and length (LOS of the growing season results show large variability and regional hot spots where later SOS often coincides with reduced productivity. A longer growing season is generally found for some locations in the south of Chile (sub-antarctic forest and Argentina (Patagonia steppe, while central Argentina (Pampa-mixed grasslands and agriculture has a shorter LOS. Some of the areas have significant shifts in SOS and LOS of one to several months. The seasonal Multivariate ENSO Indicator (MEI and the Antarctic Oscillation (AAO index have a significant impact on vegetation productivity and phenology in southeastern and northeastern Argentina (Patagonia and Pampa, central and southern Chile (mixed shrubland, temperate and sub-antarctic forest, and Paraguay (Chaco.

  3. Diversity of the genus Polylepis (Rosaceae, Sanguisorbeae in the Peruvian Andes

    Directory of Open Access Journals (Sweden)

    Wilfredo Mendoza

    2011-08-01

    Full Text Available This study provides information on the diversity of Peruvian species of Polylepis. Nineteen (19 species are reported here (more than 70% of the 27 species registered for the whole Andean region. As a result, Peru could be considered as the country with the largest diversity of Polylepis species, in comparison with Bolivia (13, Ecuador (7, Argentina (4, Colombia (3, Chile (2, and Venezuela (1. The species occur in 19 departments of Peru, with the majority of them in Cusco (10 and Ayacucho (8. Species diversity is mostly concentrated in the Peruvian southern Andes (15 species, with the region becoming the potential center of diversification of the genus Polylepis. Regarding their altitudinal distribution, the greatest diversity (18 is found between 3000 and 4000 m.

  4. Horizontal subduction zones, convergence velocity and the building of the Andes

    CERN Document Server

    Martinod, Joseph; Roperch, Pierrick; Guillaume, Benjamin; Espurt, Nicolas; 10.1016/j.epsl.2010.09.010

    2010-01-01

    We discuss the relationships between Andean shortening, plate velocities at the trench, and slab geometry beneath South America. Although some correlation exists between the convergence velocity and the westward motion of South America on the one hand, and the shortening of the continental plate on the other hand, plate kinematics neither gives a satisfactory explanation to the Andean segmentation in general, nor explains the development of the Bolivian orocline in Paleogene times. We discuss the Cenozoic history of horizontal slab segments below South America, arguing that they result from the subduction of oceanic plateaus whose effect is to switch the buoyancy of the young subducting plate to positive. We argue that the existence of horizontal slab segments, below the Central Andes during Eocene-Oligocene times, and below Peru and North-Central Chile since Pliocene, resulted (1) in the shortening of the continental plate interiors at a large distance from the trench, (2) in stronger interplate coupling and...

  5. [Domestic violence in Chile].

    Science.gov (United States)

    León, Tomás; Grez, Marcela; Prato, Juan Andrés; Torres, Rafael; Ruiz, Sergio

    2014-08-01

    According to recent surveys, there is a high prevalence of domestic violence (DV) in Chile. A systematic review was conducted in PubMed, Scielo, and Lilacs with the MesH terms "Chile", "Mental Health", "Health", "Domestic Violence", to explore the impact of DV on health in Chile. Eleven studies fulfilled the inclusion criteria. Two studies were prospective, exploring the influence of DV on maternal-infant health. Nine studies explored the influence of DV on mental health in adults. DV was associated with deranged mental health indicators specially anxiety and depressive symptoms and suicidal ideation. Similar results were observed among mothers who were victims of violence and their children. It is concluded that DV is a complex phenomenon with serious effects on health. However the number of studies on the subject is low and new follow up studies are required. Predictive models for DV and effective preventive measures are urgently needed. PMID:25424674

  6. Beyond Income: A Study of Multidimensional Poverty in Chile

    OpenAIRE

    Bronfman, Javier

    2014-01-01

    Using the latest nationally representative household survey for Chile, this paper empirically assesses multidimensional poverty both at the national and subnational level. Based on the Alkire-Foster method and focusing on four dimensions of well-being –education, health, income and living standard– this study estimates the level and depth of multidimensional poverty for Chile in 2011. At national level, the results show that fewer individuals are subject to multidimensional poverty compared t...

  7. Strike-slip faults in the southernmost Andes and the development of the Patagonian orocline

    Science.gov (United States)

    Cunningham, W. Dickson

    1993-02-01

    The Patagonian orocline is the 90° bend in the southernmost Andes between 50°S and 56°S. Paleomagnetic and structural data indicate that the orocline is, at least in part, the product of tectonic rotation. Recent field work in the Beagle Channel region of southernmost Chile provides evidence for widespread left-lateral strike-slip faulting in the internal zones of the mountain belt. Both arms of the Beagle Channel are interpreted to be left-lateral strike-slip faults based on detailed study of mesoscale strike-slip faults (Riedel shears) observed in coastal outcrops. Although much of the evidence indicates Cenozoic brittle strike-slip faulting, other fabric data, including vertical foliation zones containing horizontal quartz stretching lineations and ductile left-lateral kinematic indicators, suggest that Mesozoic ductile strike-slip or oblique-slip shearing also occurred. The implication is that the mid-Cretaceous Andean orogeny involved the transpressional inversion of the Rocas Verdes marginal basin and that transpression has been the dominant deformational regime in the region for the last 120 Ma. Regional left-lateral strike-slip faults are now recognized in all lithotectonic provinces of the southernmost Andes. A statistical study of regional lineament trends using aerial photographs and satellite imagery suggests that many unstudied lineaments are also strike-slip faults. A new model is proposed that integrates the development of strike-slip faulting and the structural evolution and uplift of the southernmost Andes with the rotational development of the orocline. The Patagonian orocline appears to be the product of broad interplate shearing accommodated by strike-slip faulting, block rotation, and contraction and is probably continuing to evolve today.

  8. Magnetotelluric study of Parincota and Lascer volcanoes, central Andes

    International Nuclear Information System (INIS)

    Complete text of publication follows. This investigation considers two regions of interest, the first one includes the zone around Parinacota (6350 m, 18 deg09'S, 69 deg08'W), a subduction related stratovolcano situated in the limit of Bolivia and Chile, which had its biggest eruptive episodes around 8000 years ago. The second zone is more to the south, around Lascar volcano (5592 m, 23 deg22'S, 67 deg41'W), located on the eastern side of the Salar de Atacama basin in northern Chile, it has been one of the most active volcanoes of the central Andes in the last years. Between September and November 2007, magnetotelluric and audio magnetotelluric sites were built in the area close to Lascar and Parinacota volcanoes. AMT sites were installed in the proximities of the volcanoes, for a more shallow view, and the MT sites, which can reach longer periods and larger depths, were installed on a profile south of Lascar, which goes from the volcanic arc, crossing the Salar de Atacama basin, and as an outer ring in the Parinacota region. Remote reference and robust techniques were used in the data processing. Induction arrows, phase tensor ellipses and strike direction of the conductivity distribution have been calculated for the AMT sites, showing some 3-D behavior for the shallower depths, with induction vectors at the closest sites to the volcanoes pointing away from them, influenced by the topography. For the higher periods, the behavior is more 2-D in both regions, with a more stable strike direction which is coherent with the induction vectors and the largest semi axis of the phase tensor ellipses. All these parameters show a strong influence in the higher periods which seem to be due to a large conductive anomaly in the backarc, according with other studies in the zone, under the Bolivian altiplano. From a first analysis, deep large conductive bodies are not present in these zones around the volcanoes. Topographic corrections have been developed as well as sensitivity

  9. Chile's energy

    Energy Technology Data Exchange (ETDEWEB)

    1988-11-18

    In recent years, a new emphasis has been placed on increasing solid fuel availability in Chile, to reach the northern mining operations where demand for power is soaring. The south of the country is well served by hydroelectric power plants (2.3 million kW). The coal industry has doubled its capacity to cope with increased copper production - the Tocopilla power plant at the Chuquicamata copper mine has been converted from oil to coal - and there has been a major investment programme in the steel industry. In 1986, 1.4 million tons of coal was mined, mostly from the Provinces of Concepcion and Arauco, the remainder from Valdivia. Since then, 70 million US dollars has been invested by COCAR SA in the Pecket deposit near Punta Arenas. Coal from Pecket should cost around 26 dollars/t compared with 60 dollars/t for underground coal. It should support an expanded coal market in Chile and may also be able to compete in the Brazilian and Argentine markets. Reserves are estimated at over 200 Mt. Petroleum reserves in Tierra del Fuego are nearly exhausted; seismic surveys in the Atacama desert are promising.

  10. Seismicity, fault plane solutions, depth of faulting, and active tectonics of the Andes of Peru, Ecuador, and southern Colombia

    Science.gov (United States)

    Suarez, G.; Molnar, P.; Burchfiel, B. C.

    1983-01-01

    The long-period P waveforms observed for 17 earthquakes in the Peruvian Andes during 1963-1976 are compared with synthetic waveforms to obtain fault-plane solutions and focal depths. The morphological units of the Peruvian Andes are characterized: coastal plains, Cordillera Occidental, altiplano and central high plateau, Cordillera Oriental, and sub-Andes. The data base and analysis methodology are discussed, and the results are presented in tables, diagrams, graphs, maps, and photographs illustrating typical formations. Most of the earthquakes are shown to occur in the transition zone from the sub-Andes to the Cordillera Oriental under formations of about 1 km elevation at focal depths of 10-38 km. It is suggested that the sub-Andean earthquakes reflect hinterland deformation of a detached fold and thrust belt, perhaps like that which occurred in parts of the Canadian Rockies. From the total crustal shortening evident in Andean morphology and the shortening rate of the recent earthquakes it is estimated that the topography and crustal root of the Andes have been formed during the last 90-135 Myr.

  11. Infrastructure Concessions in Chile

    OpenAIRE

    Gómez-Lobo, Andrés; Hinojosa, Sergio

    2000-01-01

    To increase investment in infrastructure, in the early 1990s Chiles government introduced private capital into the transport infrastructure sector, covering roads and highways, bridges, tunnels, and airports. The chosen mechanism: a concession scheme through which private firms would finance and build a given project and then operate the infrastructure for a set of number of years, recover...

  12. The Geology of Chile

    OpenAIRE

    Cabrera, Lluís; Calafat, A.; Gimeno, D.; Liesa, M.; Proenza, J.; Sàbat, F.; Sáez, Alberto; Santanach, Pere

    2008-01-01

    6 páginas.-- Book review of "The Geology of Chile", by Teresa Moreno and Wes Gibbons (eds.) (2007). Geological Society. London (United Kingdom). 414 pages, 286 figures including maps, charts and pictures; 27, 5 x 21 cm, ISBN 978-1- 86239-219-9 (hardback) and ISBN 978-1-86239-220-5 (softback).

  13. Chile's Madam President

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    After becoming the first female to win a presidential election in the socially conservative country, Chilean President-elect Michelle Bachelet created history again when unveiling a cabinet that was absolutely gender-balanced on January 30. Following similar breakthroughs of women politicians in Liberia and Germany, what happened in Chile is considered another case of women gaining power worldwide.

  14. Movilidad intrageneracional del ingreso en Chile

    OpenAIRE

    Claudio, Sapelli

    2013-01-01

    This paper estimates the different intra-generational mobility indicators for Chile on the basis of the Casen panel. Conclusions from the literature are evaluated in light of results that are based mainly on a discussion of the transition matrix. It is concluded that there is a mistaken interpretation of the data in part of the literature. A simulation is made that demonstrates that the Chilean transition matrix could be the consequence of random shocks to the effective distribution of income...

  15. Estimación del comportamiento productivo y parámetros genéticos de características predestete en bovinos de carne (Bos taurus y sus cruzas, VIII Región, Chile Estimation of pre-weaning productive performance and genetic parameters in beef cattle (Bos taurus and crosses, VIII Region of Chile

    Directory of Open Access Journals (Sweden)

    E G Cienfuegos-Rivas

    2006-01-01

    Full Text Available El objetivo del presente estudio fue determinar el comportamiento productivo al nacimiento y destete de los terneros hijos de toros Angus, Hereford y Polled Hereford con vacas Clavel, Hereford, Holstein, Polled Hereford e Híbridas (cruzas de Holstein con combinaciones de Hereford en un rebaño bovino de carne en la provincia de Ñuble, VIII Región de Chile. Los animales fueron clasificados de acuerdo a sus características fenotípicas. El comportamiento productivo se evaluó analizando 1.119 registros productivos, desde 1999 al 2000, para las variables peso al nacimiento (PN, N=1.119, peso al destete ajustado (PD205, N=660 y ganancia predestete (GDP, N=660 utilizando el método de mínimos cuadrados para determinar el efecto de la raza del toro (GRT, la raza de la vaca (GRV, el grupo contemporáneo (GC y edad de la vaca (EDV como covariable sobre las variables PN, PD205 y GDP. Los parámetros genéticos y ambientales fueron estimados usando un modelo animal con la metodología MTDFREML, empleándose análisis univariados y bivariados para la estimación de los componentes de varianza. El efecto de GRT y GC fue significativo (PThe objective was to determine the productive performance in body weight change from birth until weaning, of calves sired by Angus, Hereford and Polled Hereford with Clavel, Hereford, Holstein, Polled Hereford, and Hybrid (different Holstein and Hereford combinations cows in a beef cattle herd in the dry area of the Ñuble, province of the VIII Region in Chile. The sires and cows were classified according to their phenotypic characteristics. The productive performance was evaluated by analyzing 1,119 production records from year 1990 to 2000 for the variables: birth weight (PN, N=1,119, adjusted weaning weight (PD205, N=660 and preweaning daily gain (GDP; N=660 using the least squares method to determine the effects of breed group of the sire (GRT, breed group of the dam (GRV, and contemporary groups (GC, with age of dam

  16. ESTIMACIÓN DE COSTOS MEDIOS DE PRODUCCIÓN DE LECHE EN TRES PREDIOS DE LA REGIÓN DEL MAULE, CHILE. ESTUDIO DE CASOS Estimate of Average Production Costs for Three Dairies of Maule Region, Chile: A Case Study

    Directory of Open Access Journals (Sweden)

    Germán Lobos A.

    2001-04-01

    Full Text Available Se estimaron costos medios mensuales para el año 1998 de la producción de leche en tres lecherías ubicadas en la provincia de Linares (35º51’ lat. S. y 71º35’ long. O., Región del Maule, Chile. Las explotaciones lecheras están asociadas a la empresa PROLECHE S.A., formada con apoyo financiero de la Corporación de Fomento de la Producción (CORFO para la gestión asociativa. La tasa de descuento relevante fue estimada utilizando el Modelo de Valorización de Activos de Capital (CAPM y el Costo Promedio Ponderado del Capital (WACC. El costo medio total por litro de leche fue calculado sumando el costo medio del capital y el costo medio de la operación. Los principales resultados indican que el costo medio total fluctúa entre 0,276 y 0,619 para el predio 1, entre 0,171 y 0,282 para el predio 2, y entre 0,160 y 0,316 para el predio 3. Los menores costos medios totales se presentaron en los meses de primavera y verano debido a la mayor producción de leche y disponibilidad de forraje de menor costo. Los predios 2 y 3 se ubican en un rango de costos medios totales anuales intermedios, mientras que el valor para el predio 1 es muy superior en relación a los valores reportados por la literatura.Monthly average costs of milk production were estimated for 1998 in three dairies located in Linares province, (35º51’ S lat. and 71º35’ W long, Maule Region, Chile. The farms were associated with PROLECHE S.A., formed with the financial support of the Production Development Corporation (CORFO for associative administration. The relevant discount rate was estimated based on a Capital Asset Pricing Model (CAPM and Weighted Average Cost of Capital (WACC. The total average cost per liter of milk was calculated adding average cost of capital and average operating cost. The principal results indicate that the total average cost fluctuates between US$0.276 and US$0.619 for farm 1, between US$0.171 and US$0.282 for farm 2 and between US$0.160 and US

  17. An InSAR survey of the central Andes: Constraints on magma chamber geometry and mass balance in a volcanic arc

    Science.gov (United States)

    Pritchard, M. E.; Simons, M.

    2002-12-01

    The central Andes (14-28o S) has a high density of volcanoes, but a sparse human population, such that the activity of most volcanoes is poorly constrained. We use InSAR to conduct the first systematic observations of deformation at nearly 900 volcanoes (about 50 of which are classified ``potentially active'') during the 1992-2002 time interval. We find volcanic deformation in four locations. Subsidence is seen at Robledo (or Cerro Blanco) caldera, Argentina. We observe inflation at the stratovolcano Uturuncu, Bolivia, near stratovolcano Hualca Hualca, Peru, and in a region not associated with any known edifice on the border between Chile and Argentina that we call ``Lazufre'' because it lies between volcanoes Lastarria and Cordon del Azufre. The deformation pattern can be well explained by a uniform point-source source of inflation or deflation, but we compare these model results with those from a tri-axial point-source ellipsoid to test the robustness of estimated source depth and source strength (inferred here to be volume change). We further explore the sensitivity of these parameters to elastic half-space and layered-space models of crustal structure, and the influence of local topography. Because only one satellite look direction is available for most time periods, a variety of models are consistent with our observations. If we assume that inflation is due solely to magmatic intrusion, we can compare the rate of magma intrusion to volcanic extrusion during the decade for which data is available and the longer-term geologic rate. For the last decade, the ratio of volume intruded to extruded is between about 1-10, which agrees with previous geologic estimates in this and other volcanic arcs. The combined rate of intrusion and extrusion is within an order of magnitude of the inferred geologic rate.

  18. Mineralog??a de alteraci??n en el pozo Pte-1, campo geotermal Tinguiririca, Chile

    OpenAIRE

    Droguett, B??rbara; Morata, Diego; Clavero, Jorge; Pineda, Germ??n; Morales-Ruano, Salvador; Carrillo-Ros??a, Javier

    2012-01-01

    Este trabajo presenta los avances en el estudio mediante petrograf??a ??ptica, DRX y SEM de la mineralog??a de alteraci??n presente en el pozo PTe-1, ubicado en el campo geot??rmico Tinguiririca (Chile central). Los 813,85m de rocas perforadas pertenecen al Complejo Volc??nico Tinguiririca (Pleistoceno-Holoceno) formado por lavas, tobas y brechas volc??nicas de composici??n andes??tica. Sobre la base de las asociaciones minerales se ha determinado dos zonas de alteraci??n principales. La de m...

  19. Did growth of high Andes slow down Nazca plate subduction?

    Science.gov (United States)

    Quinteros, J.; Sobolev, S. V.

    2010-12-01

    The convergence velocity rate of the Nazca and South-American plate and its variations during the last 100 My are quite well-known from the global plate reconstructions. The key observation is that the rate of Nazca plate subduction has decreased by about 2 times during last 20 Myr and particularly since 10 Ma. During the same time the Central Andes have grown to its present 3-4 km height. Based on the thin-shell model, coupled with mantle convection, it was suggested that slowing down of Nazca plate resulted from the additional load exerted by the Andes. However, the thin-shell model, that integrates stresses and velocities vertically and therefore has no vertical resolution, is not an optimal tool to model a subduction zone. More appropriate would be modeling it with full thermomechanical formulation and self-consistent subduction. We performed a set of experiments to estimate the influence that an orogen like the Andes could have on an ongoing subduction. We used an enhanced 2D version of the SLIM-3D code suitable to simulate the evolution of a subducting slab in a self-consistent manner (gravity driven) at vertical crossections through upper mantle, transition zone and shallower lower mantle. The model utilizes non-linear temperature- and stress-dependant visco-elasto-plastic rheology and phase transitions at 410 and 660 km depth. We started from a reference case with a similar configuration as both Nazca and South-America plates. After some Mys of slow kinematicaly imposed subduction, to develop a coherent thermo-mechanical state, subduction was totally dynamic. On the other cases, the crust was slowly thickened artificially during 10 My to generate the Andean topography. Although our first results show no substantial changes on the velocity pattern of the subduction, we, however, consider this result as preliminary. At the meeting we plan to report completed and verified modeling results and discuss other possible cases of the late Cenozoic slowing down of

  20. ANDES: Statistical tools for the ANalyses of DEep Sequencing

    Directory of Open Access Journals (Sweden)

    Denison Mark R

    2010-07-01

    Full Text Available Abstract Background The advancements in DNA sequencing technologies have allowed researchers to progress from the analyses of a single organism towards the deep sequencing of a sample of organisms. With sufficient sequencing depth, it is now possible to detect subtle variations between members of the same species, or between mixed species with shared biomarkers, such as the 16S rRNA gene. However, traditional sequencing analyses of samples from largely homogeneous populations are often still based on multiple sequence alignments (MSA, where each sequence is placed along a separate row and similarities between aligned bases can be followed down each column. While this visual format is intuitive for a small set of aligned sequences, the representation quickly becomes cumbersome as sequencing depths cover loci hundreds or thousands of reads deep. Findings We have developed ANDES, a software library and a suite of applications, written in Perl and R, for the statistical ANalyses of DEep Sequencing. The fundamental data structure underlying ANDES is the position profile, which contains the nucleotide distributions for each genomic position resultant from a multiple sequence alignment (MSA. Tools include the root mean square deviation (RMSD plot, which allows for the visual comparison of multiple samples on a position-by-position basis, and the computation of base conversion frequencies (transition/transversion rates, variation (Shannon entropy, inter-sample clustering and visualization (dendrogram and multidimensional scaling (MDS plot, threshold-driven consensus sequence generation and polymorphism detection, and the estimation of empirically determined sequencing quality values. Conclusions As new sequencing technologies evolve, deep sequencing will become increasingly cost-efficient and the inter and intra-sample comparisons of largely homogeneous sequences will become more common. We have provided a software package and demonstrated its

  1. Spent Fuel in Chile

    International Nuclear Information System (INIS)

    The government has made a complete and serious study of many different aspects and possible road maps for nuclear electric power with strong emphasis on safety and energy independence. In the study, the chapter of SFM has not been a relevant issue at this early stage due to the fact that it has been left for later implementation stage. This paper deals with the options Chile might consider in managing its Spent Fuel taking into account foreign experience and factors related to safety, economics, public acceptance and possible novel approaches in spent fuel treatment. The country’s distinctiveness and past experience in this area taking into account that Chile has two research reactors which will have an influence in the design of the Spent Fuel option. (author)

  2. Waste management in Chile

    International Nuclear Information System (INIS)

    The main radioactive waste management issues to be faced by the Chilean Nuclear Energy Commission (CCHEN) are discussed herein. Research reactor spent fuel management is the most outstanding challenge at the beginning of the 21st century. Interim storage appears to be the most promising alternative, allowing fuel safekeeping until a definitive step is taken. The situation regarding radioactive waste resulting from radioisotope applications in Chile will not undergo considerable change in the near future. Low and intermediate level radioactive waste management is being safely performed followed by interim storage of conditioned wastes. The strategy in the radioactive waste management plan, to be described as well, is meant to ensure the safe storage of radioactive wastes produced in Chile. (author)

  3. Estimación de la biomasa de langostino amarillo (Cervimunida johni, aplicando Modelo Lineal Generalizado a registros de captura por área barridaen la zona central de Chile Estimating yellow squat lobster (Cervimunida johni biomass by applying a generalized linear model to catch records per swept area in central Chile

    Directory of Open Access Journals (Sweden)

    Cristian Canales

    2012-07-01

    Full Text Available La información obtenida en cruceros de evaluación directa de langostino amarillo (Cervimunida johní realizados en la zona central del Chile (32°-38°S entre 1997 y 2009, permitió modelar los cambios en la densidad anual de este recurso mediante Modelo Lineal Generalizado (MLG. El objetivo de este enfoque fue tanto minimizar el efecto de los distintos criterios y diseños de muestreo que han sido empleados en el tiempo, como también determinar los efectos que explican las variaciones en la densidad de este recurso. Lo anterior permitió estimar el valor esperado de la densidad anual para el cálculo de biomasa mediante el método de "área barrida". Los registros lance a lance de captura por unidad de área barrida (CPUA permitieron la identificación y medición de los focos de abundancia, además de caracterizar la distribución y área que ha ocupado el recurso en el tiempo. El MLG identificó como efectos significativos el año, la zona, la profundidad, y las interacciones anuales de primer orden, explicando con ello el 43% de la devianza residual del modelo. Los principales efectos que explican las variaciones de la CPUA son el año y la interacción año-zona. Se determinó que la zona con mayor abundancia promedio corresponde a la delimitada entre 32° y 34°S, de igual manera que en el rango de profundidad menor a 250 m. Dentro del período analizado, se determinó que la población de este recurso incrementó en biomasa de manera sostenida hasta el 2006, principalmente en la zona norte del área de estudio, seguida de una fuerte reducción que al 2009 equivale al 75% respecto del máximo, reflejada en una biomasa de 11.000 ton.Changes in the annual density of the yellow squat lobster (Cervimunida johni were modeled using a generalized linear model (GLM, using information obtained during direct stock assessment cruises carried out in central Chile (32°-38°S between 1997 and 2009. The purpose of this approach was to minimize the

  4. {U}/{Pb} geochronology and significance of Late Permian ignimbrites in Northern Chile

    Science.gov (United States)

    Breitkreuz, Christoph; Van Schmus, W. R.

    1996-11-01

    {U}/{Pb} zircon ages of four ignimbrite samples from a Late Paleozoic volcaniclastic succession in northern Chile are presented. The 2 km thick succession consists of the Peine Fm. and the overlying Cas Fm., which crop out at the eastern margin of the Salar de Atacama near the village of Peine. One sample was collected from the oldest ignimbrite of the succession (Lower Member of the Peine Fm.); the other three samples were collected from the Middle Member of the Cas Fm. and its assumed equivalents. The {206Pb }/{238U } ages of all samples overlap within their analytical uncertainties, which results in a best estimate of 248 ± 3 Ma (Late Permian: Harland, 1990) for deposition of the entire succession. The age for the stratigraphically older sample is statistically indistinguishable from the other three samples, so that the depositional interval could have been less than 1 million years; maximum errors in the data allow that the Peine and Cas Fms. could have formed during a time span of 6 Ma. The data provide tight constraints on the age of these units, part of which formed in the Lanquir Caldera Complex. They also have implications for the stratigraphy and paleoclimatic models of the Southern Central Andes during the Late Permian. Although the zircon fractions analyzed here document Late Permian ages, they show varying amounts of inheritance of early Paleoproterozoic (to Late Archean?) zircons and also indicate the incorporation of ca. 2.5 Ga initial common lead to varying degrees. This and results from other studies in the area lead us to infer the existence, at least during the Paleozoic, of Precam-brian basement located below the Salar de Atacama area.

  5. Genetics of colonization in Hypochaeris tenuifolia (Asteraceae, Lactuceae) on Volcán Lonquimay, Chile.

    Science.gov (United States)

    Tremetsberger, K; Stuessy, T F; Samuel, R M; Baeza, C M; Fay, M F

    2003-10-01

    Understanding the genetics of colonizing populations has been, and continues to remain, an important focus in evolutionary biology. Different theoretical models predict varying levels of genetic variation in colonizing populations depending upon strength of founder effect, gene flow and rate of population growth and immigration following colonization. We analyse overall genetic variation using amplified fragment length polymorphism markers in colonizing populations of Hypochaeris tenuifolia (Asteraceae) in the southern Andes. Volcán Lonquimay newly erupted on 25 December 1988, producing a side cone, La Navidad, and sent lava and ash into surrounding areas. Many domesticated animals (estimated at 10 000) and many natural plant populations were destroyed. Into this new open habitat have come immigrant populations of several angiosperm species, most conspicuously H. tenuifolia that forms leaf rosettes with flowering scapes to 15 cm and orange-yellow heads 1-2 cm in diameter. Genetic diversity in five founder populations in the eruption zone is compared with that from five nearby survivor populations, as well as with eight isolated northern and four southern populations from throughout the entire range of the species in Chile. Results from 477 individuals representing 447 different multilocus phenotypes, yielded 170 DNA fragments of which 144 (85%) were polymorphic. Genetic diversity within founder populations is neither lower than in survivor populations nor in isolated populations throughout the range of the species, but it is lower among founder populations than among other populations immediately and distantly outside the zone of disturbance. Closest genetic similarity occurs between founders and nearby survivor populations as well as those in adjacent southern regions. PMID:12969468

  6. Abandoned Beach Ridges in the Mejillones Peninsula, Northern Chile: Implications for Paleoseismology of Great Subduction Earthquakes.

    Science.gov (United States)

    del Río, I. A.; Gonzalez, G.; Antinao, J. L.; McDonald, E.; González-Carrasco, J. F.; Shrivastava, M. N.

    2015-12-01

    The Mejillones Peninsula, in northern Chile, shows a well-preserved set of beach ridges parallel to the present coast. These beach ridges can be observed up to 20 km inland and at 200 m above sea level. Previous dating performed in fossils extracted from the oldest beach ridges yielded ages of 400 ka (Victor et al., 2011). However, numerical ages for younger beach ridges have not been determined, therefore a complete time record is not available. InSar data show that the Mejillones Peninsula was uplifted several centimeters during the last two subduction earthquakes (Antofagasta Mw 8.1, 1995 earthquake and the Mw 7.7, 2007 Tocopilla earthquake) occurred in the area (Loveless et al., 2010). A permanent GPS station deployed by CALTECH (http://web.gps.caltech.edu/~jeff/andes/) in this peninsula has measured a coseismic uplift during the 2007 Tocopilla earthquake. This data suggest that the beach ridges were abandoned as a consequence of coseismic uplift during great subduction earthquakes and therefore they represent the long-term record of past earthquakes. In order to prove this hypothesis we excavated five trenches across the beach ridges. Our idea is to look for stratigraphic evidence of the abandonment mechanism and to collect samples for dating the beach ridges using the method of optically stimulated luminescence (OSL). The ages will be used to estimate long-term uplift rate and temporal variation of this rate. By confronting short-term uplift rate provided by GPS data with long-term rate we hope to know what it is the amount of the coseismic slip that remain in the geological record.

  7. Changing Student Attitudes using Andes, An Intelligent Homework System

    Science.gov (United States)

    van de Sande, Brett; Vanlehn, Kurt; Treacy, Don; Shelby, Bob; Wintersgill, Mary

    2007-03-01

    The size of introductory physics lectures often inhibits personal homework assistance and timely corrective feedback. Andes, an intelligent homework help system designed for two semesters of introductory physics, can fill this need by encouraging students to use sound problem solving techniques and providing immediate feedback on each step of a solution. On request, Andes provides principles-based hints based on previous student actions. A multi-year study at the U.S. Naval Academy demonstrates that students using Andes perform better than students working the same problems as graded pencil and paper homeworks. In addition, student attitude surveys show that Andes is preferred over other homework systems. These findings have implications for student attitudes toward, and mastery of, physics. See http://www.andes.pitt.edu for more information.

  8. Contrasting climate change impact on river flows from high-altitude catchments in the Himalayan and Andes Mountains.

    Science.gov (United States)

    Ragettli, Silvan; Immerzeel, Walter W; Pellicciotti, Francesca

    2016-08-16

    Mountain ranges are the world's natural water towers and provide water resources for millions of people. However, their hydrological balance and possible future changes in river flow remain poorly understood because of high meteorological variability, physical inaccessibility, and the complex interplay between climate, cryosphere, and hydrological processes. Here, we use a state-of-the art glacio-hydrological model informed by data from high-altitude observations and the latest climate change scenarios to quantify the climate change impact on water resources of two contrasting catchments vulnerable to changes in the cryosphere. The two study catchments are located in the Central Andes of Chile and in the Nepalese Himalaya in close vicinity of densely populated areas. Although both sites reveal a strong decrease in glacier area, they show a remarkably different hydrological response to projected climate change. In the Juncal catchment in Chile, runoff is likely to sharply decrease in the future and the runoff seasonality is sensitive to projected climatic changes. In the Langtang catchment in Nepal, future water availability is on the rise for decades to come with limited shifts between seasons. Owing to the high spatiotemporal resolution of the simulations and process complexity included in the modeling, the response times and the mechanisms underlying the variations in glacier area and river flow can be well constrained. The projections indicate that climate change adaptation in Central Chile should focus on dealing with a reduction in water availability, whereas in Nepal preparedness for flood extremes should be the policy priority. PMID:27482082

  9. Palaeoindian occupation of the Atacama Desert, northern Chile

    Science.gov (United States)

    Grosjean, Martin; Núñez, Lautaro; Cartajena, Isabel

    2005-10-01

    Palaeoindian occupation of the Atacama Desert in northern Chile has been found between 12 600 and 10 200 cal. yr BP. The new site at Salar Punta Negra (24°28S/60°53W/2976 m) includes about 1000 classifiable, mostly unifacial artefacts and, uniquely, three different diagnostic types of early projectile points. Two of the Lateglacial/early Holocene projectile types have wide distribution and are known from different geographical areas in South America: the Palaeoindian Fell fish-tail point mainly from the southern cone of South America, and the triangular Tuina points typical of the Puna of the south-central Andes in northern Chile and northwestern Argentina. In addition, we found a third type, a stemmed point typical for the Salar Punta Negra. Filling a large geographical gap of Fell occupation, the site at Salar Punta Negra provides evidence for generally much higher mobility and diversity of early cultures, and supports an Andean-Pacific route for early human exploration of South America to the south through the desert at intermediate altitudes. Contemporaneous high-amplitude climatic changes were fundamental preconditions to provide adequate environments and habitats, and to make Palaeoindian hunting-gathering occupation possible in the Atacama Desert.

  10. Isotopic composition and origin of the precipitation in Northern Chile

    Energy Technology Data Exchange (ETDEWEB)

    Aravena, R. [Department of Earth Sciences, University of Waterloo, Waterloo (Canada); Suzuki, O. [Exploracion y Desarrollo de Recursos Hidricos, Santiago (Chile); Pena, H. [Direccion General de Aguas, Ministerio de Obras Publicas, Santiago (Chile); Pollastri, A. [Comision Chilena de Energia Nuclear, Santiago (Chile); Fuenzalida, H. [Departamento de Geofisica, Universidad of Chile, Santiago (Chile); Grilli, A. [Empresa Metropolitana de Obras Sanitarias, Santiago (Chile)

    1999-06-01

    A 3 a data set of isotopes in precipitation from northern Chile show a very distinct pattern, with {delta}{sup 18}O values ranging between -18 and -15per thousand at high altitude stations, compared to {delta}{sup 18}O values between -10 and -6per thousand at the lower altitude areas. The {sup 18}O-depleted values observed in the high altitude area, the Altiplano, are related to processes that affect the air masses that originated over the Atlantic, cross the Amazon Basin (continental effect), ascend the Andes (altitude effect) and precipitated (convective effect) in the Altiplano. It is postulated that a second source of moisture, associated with air masses from the Pacific, may contribute to the {sup 18}O-enriched values observed in the lower altitude areas. Similar isotopic patterns are documented in springs and groundwater indicating that the data presented in this paper are an accurate representation of the long term behavior isotopic composition of rain in northern Chile. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  11. La quinua en Chile

    OpenAIRE

    Martinez, Enrique A.; Fuentes, Francisco F.; Chia, Eduardo; Namdar-Irani, Mina; Olguin, Pablo; Saa, Constanza; Thomet, Max; Vidal, Alejandra

    2014-01-01

    La biogeografía de la quinua (Chenopodium quinua Willd.) presenta una visión global de un cultivo menor en la agricultura chilena que tiene una amplia extensión geográfica (18°S-47°S). Su alta diversidad genética demuestra que es una de las especies de mayor importancia en Los Andes de Sudamérica. El proceso de domesticación de la quinua se ha realizado en distintas zonas geográficas, lo cual ha significado la existencia de una amplia variación de caracteres morfológicos y de adaptación medio...

  12. Primary Medical Care in Chile

    DEFF Research Database (Denmark)

    Scarpaci, Joseph L.

    Primary medical care in Chile: accessibility under military rule [Front Cover] [Front Matter] [Title Page] Contents Tables Figures Preface Chapter 1: Introduction Chapter 2: The Restructuring of Medical Care Financing in Chile Chapter 3: Inflation and Medical Care Accessibility Chapter 4: Help......-Seeking Behavior of the Urban Poor Chapter 5: Spatial Organization and Medical Care Accessibility Chapter 6: Conclusion...

  13. Desigualdad Geográfica en Chile

    Directory of Open Access Journals (Sweden)

    Claudio A. Agostini

    2007-03-01

    Full Text Available Despite success in reducing poverty over the last twenty years, inequality in Chile has remained virtually unchanged, making Chile one of the least equal countries in the world. High levels of inequality have been shown to hamper further reductions in poverty as well as economic growth and local inequality has been shown to affect such outcomes as violence and health. The study of inequality at the local level is thus crucial for understanding the economic well-being of a country. Local measures of inequality have been difficult to obtain, but recent theoretical advances have enabled the combination of survey and census data to obtain estimators of inequality that are robust at disaggregated geographic levels. In this paper, we employ this methodology to produce consistent estimators of inequality for every county in Chile. We find a great deal of variation in inequality, with countylevel Gini coefficients ranging from 0.41 to 0.63.

  14. Regulated electricity retailing in Chile

    Energy Technology Data Exchange (ETDEWEB)

    Galetovic, Alexander, E-mail: alexander@galetovic.cl [Facultad de Ciencias Economicas y Empresariales, Universidad de los Andes, Santiago, Chile. Av. San Carlos de Apoquindo 2200, Las Condes, Santiago (Chile); Munoz, Cristian M., E-mail: cmunozm@aes.com [AES Gener and Departamento de Ingenieria Electrica, Universidad Catolica de Chile (Chile)

    2011-10-15

    While some countries have unbundled distribution and retailing, skeptics argue that the physical attributes of electricity make retailers redundant. Instead, it is claimed that passive pass through of wholesale prices plus regulated charges for transmission and distribution suffice for customers to benefit from competitive generation markets. We review the Chilean experience with regulated retailing and pass through of wholesale prices. We argue that when energy wholesale prices are volatile and prices are stabilized, distortions emerge. Regulated retailers gain little by mitigating or correcting them. On the contrary, sometimes price distortions increase their profits. We estimate the cost of three distortions that neither regulated retailers nor the regulator have shown any interest in correcting. - Highlights: > We review Chile's experience with regulated electricity retailing. > Distortions emerge when energy wholesale prices are volatile and prices stabilized. > Regulated retailers gain little by mitigating or correcting distortions. > Sometimes price distortions increase retailers' profits. > We estimate the cost of three distortions, which retailers have not corrected.

  15. Regulated electricity retailing in Chile

    International Nuclear Information System (INIS)

    While some countries have unbundled distribution and retailing, skeptics argue that the physical attributes of electricity make retailers redundant. Instead, it is claimed that passive pass through of wholesale prices plus regulated charges for transmission and distribution suffice for customers to benefit from competitive generation markets. We review the Chilean experience with regulated retailing and pass through of wholesale prices. We argue that when energy wholesale prices are volatile and prices are stabilized, distortions emerge. Regulated retailers gain little by mitigating or correcting them. On the contrary, sometimes price distortions increase their profits. We estimate the cost of three distortions that neither regulated retailers nor the regulator have shown any interest in correcting. - Highlights: → We review Chile's experience with regulated electricity retailing. → Distortions emerge when energy wholesale prices are volatile and prices stabilized. → Regulated retailers gain little by mitigating or correcting distortions. → Sometimes price distortions increase retailers' profits. → We estimate the cost of three distortions, which retailers have not corrected.

  16. Chile rural electrification cooperation

    Energy Technology Data Exchange (ETDEWEB)

    Flowers, L. [National Renewable Energy Lab., Golden, CO (United States)

    1997-12-01

    The author describes a joint program to use renewables for rural electrification projects in Chile. The initial focus was in a limited part of the country, involving wind mapping, pilot project planning, training, and development of methodologies for comparative evaluations of resources. To this point three wind hybrid systems have been installed in one region, as a part of the regional private utility, and three additional projects are being designed. Additional resource assessment and training is ongoing. The author points out the difficulties in working with utilities, the importance of signed documentation, and the need to look at these programs as long term because of the time involved in introducing such new technologies.

  17. Biomasa en Chile

    OpenAIRE

    Nilsson Cifuentes, Gabriel; Rodríguez Monroy, Carlos

    2012-01-01

    El artículo presenta el desarrollo de la biomasa en Chile, dentro del complejo marco energético existente en el país, el cual, aún no logra potenciar e incentivar el desarrollo de energías renovables y depende fuertemente de los combustibles fósiles, acrecentando el riesgo latente de sufrir una crisis energética, en el mediano plazo, producto de la paulatina incorporación de nuevas centrales generadoras de energías, que satisfagan la creciente demanda energética pronosticada. Este ar...

  18. Chile: Transantiago recargado Chile: Transantiago Reloaded

    Directory of Open Access Journals (Sweden)

    RODRIGO MARDONES Z

    2008-01-01

    Full Text Available El 2007 fue el segundo año del gobierno de Michelle Bachelet. Se trató de un año sin elecciones; con un buen desempeño económico, a pesar de una inflación creciente en los últimos meses; y marcado por la discusión sobre escándalos de corrupción. Sin embargo, lo que más afectó al Gobierno fue la desastrosa puesta en marcha de la reforma al sistema de transporte público de la capital: Transantiago. Este puso un velo sobre los importantes avances en materias previsionales y educacionales, cuestionando no sólo la capacidad ejecutiva del Gobierno, sino que profundizando un flanco de indisciplina al interior de la coalición oficialista (Concertación; síntoma de su desgaste después de 17 años ocupando la Presidencia de Chile.The year 2007 was the second in Michelle Bachelet’s presidencial term. It was a year free of elections, exhibiting a fairly good economic performance, despite the high rate of inflation shown during the last months. Public discussion on corruption escandals was frequent; however, the most important issue was the disestrous beginning of the reform on the public transportation system of the country’s capital: Transantiago. This has placed a veil over the important achievements on the pension system and education, questioning not only the government’s capacity, but also opening and edge of indiscipline within the ruling coalition (Concertación, which is a symtom of its erosion after 17 years in the presidential office.

  19. 27 CFR 9.154 - Chiles Valley.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Chiles Valley. 9.154... Chiles Valley. (a) Name. The name of the viticultural area described in this section is “Chiles Valley.” (b) Approved maps. The appropriate maps for determining the boundary of the Chiles...

  20. The age and constitution of Cerro Campanario, a mafic stratovolcano in the Andes of central Chile

    Science.gov (United States)

    Hildreth, W.; Singer, B.; Godoy, E.; Munizaga, F.

    1998-01-01

    Cerro Campanario, a towering landmark on the continental divide near Paso Pehuenche, is a glacially eroded remnant of a mafic stratovolcano that is much younger than previously supposed. Consisting of fairly uniform basaltic andesite, rich in olivine and plagioclase, the 10-15 km3 edifice grew rapidly near the end of the middle Pleistocene, about 150-160 ka, as indicated by 40Ar/39Ar and unspiked K-Ar analyses of its lavas.

  1. The age and constitution of Cerro Campanario, a mafic stratovolcano in the Andes of Central Chile

    OpenAIRE

    Wes Hildreth; Brad Singer; Estanislao Godoy; Francisco Munizaga

    1998-01-01

    ABSTRACT Cerro Campanario, a towering landmark on the continental divide near Paso Pehuenche, is a glacially eroded remnant of a mafic stratovolcano that is much younger than previously supposed. Consisting of fairly uniform basaltic andesite, rich in olivine and plagioclase, the 10-15 km³ edifice grew rapidly near the end of the middle Pleistocene, about 150-160 ka, as indicated by 40Ar/39Ar and unspiked K-Ar analyses of its lavas.La edad y formación del cerro Campanario, un estratovolcán má...

  2. Crustal contributions to arc magmatism in the Andes of Central Chile

    Science.gov (United States)

    Hildreth, W.; Moorbath, S.

    1988-01-01

    Fifteen andesite-dacite stratovolcanoes on the volcanic front of a single segment of the Andean arc show along-arc changes in isotopic and elemental ratios that demonstrate large crustal contributions to magma genesis. All 15 centers lie 90 km above the Benioff zone and 280??20 km from the trench axis. Rate and geometry of subduction and composition and age of subducted sediments and seafloor are nearly constant along the segment. Nonetheless, from S to N along the volcanic front (at 57.5% SiO2) K2O rises from 1.1 to 2.4 wt %, Ba from 300 to 600 ppm, and Ce from 25 to 50 ppm, whereas FeO*/MgO declines from >2.5 to 1.4. Ce/Yb and Hf/Lu triple northward, in part reflecting suppression of HREE enrichment by deep-crustal garnet. Rb, Cs, Th, and U contents all rise markedly from S to N, but Rb/Cs values double northward - opposite to prediction were the regional alkali enrichment controlled by sediment subduction. K/Rb drops steeply and scatters greatly within many (biotite-free) andesitic suites. Wide diversity in Zr/Hf, Zr/Rb, Ba/Ta, and Ba/La within and among neighboring suites (which lack zircon and alkali feldspar) largely reflects local variability of intracrustal (not slab or mantle) contributions. Pb-isotope data define a limited range that straddles the Stacey-Kramers line, is bracketed by values of local basement rocks, in part plots above the field of Nazca plate sediment, and shows no indication of a steep (mantle+sedimentary) Pb mixing trend. 87Sr/86Sr values rise northward from 0.7036 to 0.7057, and 143Nd/144Nd values drop from 0.5129 to 0.5125. A northward climb in basal elevation of volcanic-front edifices from 1350 m to 4500 m elevation coincides with a Bougueranomaly gradient from -95 to -295 mgal, interpreted to indicate thickening of the crust from 30-35 km to 50-60 km. Complementary to the thickening crust, the mantle wedge beneath the front thins northward from about 60 km to 30-40 km (as slab depth is constant). The thick northern crust contains an abundance of Paleozoic and Triassic rocks, whereas the proportion of younger arc-intrusive basement increases southward. Primitive basalts are unknown anywhere along the arc. Base-level isotopic and chemical values for each volcano are established by blending of subcrustal and deep-crustal magmas in zones of melting, assimilation, storage and homogenization (MASH) at the mantle-crust transition. Scavenging of mid-to upper-crustal silicic-alkalic melts and intracrustal AFC (prominent at the largest center) can subsequently modify ascending magmas, but the base-level geochemical signature at each center reflects the depth of its MASH zone and the age, composition, and proportional contribution of the lowermost crust. ?? 1988 Springer-Verlag.

  3. The Bolivian and Maipo Oroclines: Two first scale structural features of the Central Andes

    Science.gov (United States)

    Arriagada, C. A.

    2013-05-01

    Two remarkable curvatures of the orogenic system of the Central Andes are the Bolivian and the Maipo Oroclines. While the former has been widely studied, the latter in central Chile, where few, geographically restricted, paleomagnetic studies have been carried out, knowledge about vertical-axis rotations is scarce. Here we show the results of the paleomagnetic studies carried out in the last years along the Central Andes within the Bolivian and Maipo Oroclines. Along-strike variations in horizontal shortening in the back- arc provided an efficient mechanism to explain the Bolivian Orocline and block rotations of the forearc region in northern Chile and southern Peru. As a first approximation, it appears reasonable that the arcuate shape of the Maipo Orocline could be accompanied by a significant pattern of rotations about a vertical axis in the forearc region and by a progressive decrease of crustal shortening and the resulting topography from north to south in the back-arc region. Furthermore, although the Maipo Orocline is located more than 1000 km south of the axial zone of the Central Andes, south of 30, clockwise rotations of up to 20 could have occurred during the evolution of the Bolivian Orocline. While the northern segment of the Maipo orocline corresponds with the ongoing subduction of the Pampean flat slab segment which proceeds nearly horizontally beneath the South American lithosphere, the southern segment coincides with the normal subduction segment developed to the south of 33S. The Maipo Orocline is thought to be result of collision of the Challenger Fracture Zone and Juan Fernández Ridge with the continent since 25 Ma. The southern flank of the Maipo Orocline can be traced along strike to around 38S. North of 33S, previous studies show no evidence for significant tectonic rotations. In contrary, south of 33S, both in the Coastal Cordillera and High Andes, clockwise block rotations have been observed and attributed to in situ block rotations in

  4. Estimación de mortalidad natural e incertidumbre para congrio dorado (Genypterus blacodes Schneider, 1801 en la zona sur-austral de Chile Estimation of natural mortality and uncertainty in pink cusk-eel (Genypterus blacodes Schneider, 1801 in southern Chile

    Directory of Open Access Journals (Sweden)

    Rodrigo Wiff

    2011-07-01

    Full Text Available El congrio dorado (Genypterus blacodes es un pez demersal de gran importancia económica en la pesquería multiespecífica y multiflota que opera en la zona sur-austral de Chile (41°28'-57°00'S. Desde principio de los años noventas se consideró para efectos de la evaluación poblacional la existencia de un único stock. Sin embargo, varios antecedentes relacionados con la historia de vida y demografía han conducido a que, desde el año 2005, la evaluación de esta especie se realice bajo dos stocks administrativos, uno en la zona norte (41°28'-47°00'S y otro en la zona sur (47°00'-57°00'S. La separación de stocks produce una demanda por actualización de parámetros de historia de vida, entre éstos la mortalidad natural (M. En este trabajo se estimó M para el congrio dorado mediante métodos empíricos aplicados por zona y sexo. La incertidumbre en M fue incorporada a través de remuestreo de Monte Carlo considerando dos fuentes de error, una proveniente de los parámetros de historia de vida que alimentan los modelos empíricos y otra, proveniente de los coeficientes que los definen. El promedio de M mediante los diferentes métodos mostró, para una determinada zona, importantes diferencias entre sexos, como también para sexos conjuntos entre zonas de pesca. Los individuos de la zona norte presentaron mayor M que aquellos provenientes de la zona sur y los coeficientes de variación por método son altamente dependientes del tipo de error incorporado. El método de Pauly (1980 parece ser el más adecuado para el congrio dorado entregando valores de M para sexos conjuntos de 0,27 año-1 (IC: 0,13-0,47 en la zona norte y 0,23 año-1 (IC: 0,11-0,40 en la zona sur.Pink cusk-eel (Genypterus blacodes is a demersal fish of high economic importance for the multi-species and multi-fleet fishery operating off far-southern Chile (41°28'-57°00'S. Since the early 1990s, the existence of a single stock was assumed for purposes of stock

  5. Annual narrative report: Lake Andes National Wildlife Refuge, Karl Mundt National Wildlife Refuge, and Lake Andes Wetland Management District: Calendar year 1975

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This collection of monthly activity reports summarizes activities on Lake Andes NWR, Lake Andes WMD, and Karl E. Mundt NWR during the 1975 calendar year. Resource...

  6. Moho topography in the central Andes and its geodynamic implications

    Science.gov (United States)

    Yuan, X.; Sobolev, S. V.; Kind, R.

    2002-06-01

    P-to-S converted waves at the continental Moho together with waves multiply reflected between the Earth's surface and the Moho have been used to estimate the Moho depth and average crustal Vp/ Vs variations in the central Andes. Our analysis confirms and significantly complements the Moho depth estimates previously obtained from wide-angle seismic studies and receiver functions. The resulting crustal thickness varies from about 35 km in the forearc region to more than 70 km beneath the plateau and thins (30 km) further to the east in the Chaco plains. Beneath the Andean plateau, the Moho is deeper in the north (Altiplano) and shallower in the south (Puna), where the plateau attains its maximum elevation. A non-linear relation exists between crustal thickness and elevation (and Bouguer gravity), suggesting that the crust shallower than 50-55 km is predominately felsic in contrast to a predominately mafic crust below. Such a relation also implies a 100 km thick thermal lithosphere beneath the Altiplano and with a lithospheric thinning of a few tens of kilometers beneath the Puna. Absence of expected increase in lithospheric thickness in regions of almost doubled crust strongly suggests partial removal of the mantle lithosphere beneath the entire plateau. In the Subandean ranges at 19-20°S, the relation between altitude and crustal thickness indicates a thick lithosphere (up to 130-150 km) and lithospheric flexure. Beneath a relative topographic low at the Salar de Atacama, a thick crust (67 km) suggests that the lithosphere in this region is abnormally cold and dynamically subsided, possibly due to coupling with the subducting plate. This may be related to the strongest (Ms=8.0) known intra-slab earthquake in the central Andes that happened very close to this region in 1950. The average crustal Vp/ Vs ratio is about 1.77 for the Altiplano-Puna and it reaches the highest values (1.80-1.85) beneath the volcanic arc, indicating high ambient crustal temperatures and

  7. On the uplift anomaly of the Arica Bend, Western Central Andes

    Science.gov (United States)

    Madella, Andrea; Delunel, Romain; Szidat, Sönke; Schlunegger, Fritz

    2015-04-01

    The architecture of the Western Andes is remarkably constant between southern Peru and northern Chile. An exception, however, is present near Arica at 18°S, where the Andes change their strike direction by ca. 50° and the Coastal Cordillera is absent over a lateral width of 50 km. Here, we propose a large-scale model to explain the Ma-long low-uplift rate of the Arica Bend in connection with interplate coupling and continental wedge-top basin evolution. We complement new geomorphic and sedimentological observations with structural, stratigraphic and seismic data compiled from the literature. We additionally present a new set of 14C ages to infer the Holocene uplift pattern of the region, which we support with stream profile analysis. Results show that the absence of a sediment barrier and the amphitheater-shaped topography at the Arica Bend has conditioned a relatively high sediment discharge to the corresponding trench segment since 2.7 Ma and possibly earlier. However, the 14C ages and the river profile analyses yield contradicting high coastal uplift rates for the past 10 ka. It appears that, at the large scale, higher sediment supply likely reduced the friction at the interplate boundary, keeping the uplift push at lower levels and the Coastal Cordillera submerged below Arica, thereby explaining the lower frequency of large subduction earthquakes in the area. Nonetheless, at a smaller scale, Quaternary sea-level fluctuations repeatedly shifted the water-load on the accretionary wedge, thereby inducing short-term elastic buckling, which has perturbed the trunk stream's profile.

  8. Intraseasonal variability of organized convective systems in the Central Andes: Relationship to Regional Dynamical Features

    Science.gov (United States)

    Mohr, K. I.; Slayback, D. A.; Nicholls, S.; Yager, K.

    2013-12-01

    The Andes extend from the west coast of Colombia (10N) to the southern tip of Chile (53S). In southern Peru and Bolivia, the Central Andes is split into separate eastern and western cordilleras, with a high plateau (≥ 3000 m), the Altiplano, between them. Because 90% of the Earth's tropical mountain glaciers are located in the Central Andes, our study focuses on this region, defining its zonal extent as 7S-21S and the meridional extent as the terrain 1000 m and greater. Although intense convection occurs during the wet season in the Altiplano, it is not included in the lists of regions with frequent or the most intense convection. The scarcity of in-situ observations with sufficient density and temporal resolution to resolve individual storms or even mesoscale-organized cloud systems and documented biases in microwave-based rainfall products in poorly gauged mountainous regions have impeded the development of an extensive literature on convection and convective systems in this region. With the tropical glaciers receding at unprecedented rates, leaving seasonal precipitation as an increasingly important input to the water balance in alpine valley ecosystems and streams, understanding the nature and characteristics of the seasonal precipitation becomes increasingly important for the rural economies in this region. Previous work in analyzing precipitation in the Central Andes has emphasized interannual variability with respect to ENSO, this is the first study to focus on shorter scale variability with respect to organized convection. The present study took advantage of the University of Utah's Precipitation Features database compiled from 14 years of TRMM observations (1998-2012), supplemented by field observations of rainfall and streamflow, historical gauge data, and long-term WRF-simulations, to analyze the intraseasonal variability of precipitating systems and their relationship regional dynamical features such as the Bolivian High. Through time series and

  9. Radiation doses in neuroangiography for a clinical hospital in Chile

    International Nuclear Information System (INIS)

    The objective of this study is to estimate the levels of radiation to the patient in neuroangiography procedures diagnostic and therapy in a Chile's Hospital, using a biplane angiographic system Siemens model ArtisZee. This research was conducted under the auspices of the International Atomic Energy Agency and the support of their radiation protection programs for patients

  10. Sr and Nd isotopic and trace element compositions of Quaternary volcanic centers of the southern Andes

    International Nuclear Information System (INIS)

    Isotopic compositions of samples from six Quaternary volcanoes located in the northern and southern extremities of the Southern Volcanic Zone (SVZ, 33-460S) of the Andes and from four centers in the Austral Volcanic Zone (AVZ, 49-540S) range for 87Sr/86Sr from 0.70280 to 0.70591 and for 143Nd/144Nd from 0.51314 to 0.51255. Basalts and basaltic andesites from three centers just north of the Chile Rise-Trench triple junction have 87Sr/86Sr, 143Nd/144Nd, La/Yb, Ba/La and Hf/Lu that lie within the relatively restricted ranges of the basic magmas erupted from the volcanic centers as far north as 350S in the SVZ of the Andes. The trace element and Sr and Nd isotopic characteristics of these magmas may be explained by source region contamination of subarc asthenosphere, with contaminants derived from subducted pelagic sediments and seawater-altered basalts by dehydration of subducted oceanic lithosphere. In the northern extremity of the SVZ between 330 and 340S, basaltic andesites and andesites have higher 87Sr/86Sr, Rb/Cs, and Hf/Lu, and lower 143Nd/144Nd than basalts and basaltic andesites erupted farther south in the SVZ, which suggests involvement of components derived from the continental crust. In the AVZ, the most primitive sample, high-Mg andesite from the southernmost volcanic center in the Andes (540S) has Sr and Nd isotopic compositions and K/Rb and Ba/La similar to MORB. The high La/Yb of this sample suggests formation by small degrees of partial melting of subducted MORB with garnet as a residue. Samples from centers farther north in the AVZ show a regionally regular northward increase in SiO2, K2O, Rb, Ba, Ba/La, and 87Sr/86Sr and decrease in MgO, Sr, K/Rb, Rb/Cs, and 143Nd/144Nd, suggesting increasingly greater degrees of fractional crystallization and associated intra-crustal contamination. (orig./SHOE)

  11. Lake Andes Easement Refuges: Narrative report: September to December, 1946

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report summarizes activities on Lake Andes NWR between September and December of 1946. Water conditions, waterfowl, furbearers, maintenance and...

  12. Interseismic coupling and seismic potential along the Central Andes subduction zone

    Science.gov (United States)

    Chlieh, Mohamed; Perfettini, Hugo; Tavera, Hernando; Avouac, Jean-Philippe; Remy, Dominique; Nocquet, Jean-Mathieu; Rolandone, FréDéRique; Bondoux, Francis; Gabalda, Germinal; Bonvalot, Sylvain

    2011-12-01

    We use about two decades of geodetic measurements to characterize interseismic strain build up along the Central Andes subduction zone from Lima, Peru, to Antofagasta, Chile. These measurements are modeled assuming a 3-plate model (Nazca, Andean sliver and South America Craton) and spatially varying interseismic coupling (ISC) on the Nazca megathrust interface. We also determine slip models of the 1996 Mw = 7.7 Nazca, the 2001 Mw = 8.4 Arequipa, the 2007 Mw = 8.0 Pisco and the Mw = 7.7 Tocopilla earthquakes. We find that the data require a highly heterogeneous ISC pattern and that, overall, areas with large seismic slip coincide with areas which remain locked in the interseismic period (with high ISC). Offshore Lima where the ISC is high, a Mw˜8.6-8.8 earthquake occurred in 1746. This area ruptured again in a sequence of four Mw˜8.0 earthquakes in 1940, 1966, 1974 and 2007 but these events released only a small fraction of the elastic strain which has built up since 1746 so that enough elastic strain might be available there to generate a Mw > 8.5 earthquake. The region where the Nazca ridge subducts appears to be mostly creeping aseismically in the interseismic period (low ISC) and seems to act as a permanent barrier as no large earthquake ruptured through it in the last 500 years. In southern Peru, ISC is relatively high and the deficit of moment accumulated since the Mw˜8.8 earthquake of 1868 is equivalent to a magnitude Mw˜8.4 earthquake. Two asperities separated by a subtle aseismic creeping patch are revealed there. This aseismic patch may arrest some rupture as happened during the 2001 Arequipa earthquake, but the larger earthquakes of 1604 and 1868 were able to rupture through it. In northern Chile, ISC is very high and the rupture of the 2007 Tocopilla earthquake has released only 4% of the elastic strain that has accumulated since 1877. The deficit of moment which has accumulated there is equivalent to a magnitude Mw˜8.7 earthquake. This study thus

  13. Atmospheric transmissivity: Distribution and empirical estimation around the central andes

    NARCIS (Netherlands)

    Baigorria, G.A.; Villegas, E.B.; Trebejo, I.; Carlos, J.F.; Quiroz, R.

    2004-01-01

    This study of the distribution in space and time of atmospheric transmissivity takes into account the fact that, in complex terrain, many factors affect this variable; thus, it is not possible to use the generalizations that can be applied under more homogeneous conditions. Climatic controls, topogr

  14. Summer energy balance and ablation of high elevation glaciers in the central Chilean Andes

    Science.gov (United States)

    Brock, Benjamin; Rivera, Andres; Burger, Flavia; Bravo, Claudio

    2014-05-01

    Glaciers of the semi-arid central Chilean Andes are an important freshwater source for the populous Central Valley region of Chile, but have been shrinking in recent decades. The surface energy balance of these glaciers is of high scientific interest as summer ablation occurs through both sublimation and melt. During the 2012-13 Austral Summer a glacio-meteorological monitoring programme was established on Olivares Alfa (3.9 km2, 4130-4800 m elevation) and Beta (8.3 km2, 3620-4850 m elevation) Glaciers and their forelands in the Upper Olivares Valley, 33°00'-33°11' S, 70°05'-70°15' W, approximately 50 km north-east of Santiago. This included complete automatic weather stations (AWSs) with sonic rangers to record surface ablation on the ablation zones of the two glaciers, and one AWS in the proglacial area of Olivares Alfa Glacier including precipitation gauge. To complement these point data, daily images of the glaciers were captured with fixed cameras in order to calculate snow cover and albedo distributions. To calculate the surface energy balance and rates of melt and sublimation, a model was developed which uses direct AWS measurements of the radiative fluxes and calculates the turbulent fluxes of sensible and latent heat using the bulk aerodynamic approach. The model also calculates the subsurface heat flux and includes a simple scheme to estimate refreezing of melt water within surface snow or ice. Meteorological data and model results for the December to May period will be presented in this paper. Model calculations match closely the cumulative ablation curve of the sonic ranger at Olivares Alfa, with a slight overestimation, and overestimate cumulative ablation recorded by the sonic ranger at Olivares Beta, possibly due, at least in part, to uncertain snow density values. Modelled cumulative ablation in the December-April period is 2.2 m water equivalent (w.e.) at Olivares Alfa (0.10 m sublimation, 2.10 m melt) and 2.34 m w.e. at Olivares Beta (0.18 m

  15. Assessment of climate change impacts on the hydrology of the Peruvian Amazon-Andes basin

    OpenAIRE

    Casimiro, W. S. L.; Labat, D.; Guyot, Jean-Loup; Ardoin Bardin, Sandra

    2011-01-01

    In this article, we propose an investigation of the modifications of the hydrological response of two Peruvian AmazonasAndes basins in relationship with the modifications of the precipitation and evapotranspiration rates inferred by the IPCC. These two basins integrate around 10% of the total area of the Amazonian basin. These estimations are based on the application of two monthly hydrological models, GR2M and MWB3, and the climatic projections come from BCM2, CSMK3 and MIHR models for A1B a...

  16. Direction and timing of uplift propagation in the Peruvian Andes deduced from molecular phylogenetics of highland biotaxa

    OpenAIRE

    Picard, D; Sempéré, Thierry; Plantard, O.

    2008-01-01

    Physical paleoaltimetric methods are increasingly used to estimate the amount and timing of surface uplift in orogens. Because the rise of mountains creates new ecosystems and triggers evolutionary changes biological data may also be used to assess the development and timing of regional surface uplift. Here we apply this idea to the Peruvian Andes through a molecular phylogeographic and phylochronologic analysis of Globodera pallida. a potato parasite nematode that requires cool temperatures ...

  17. Estimación de mortalidad natural e incertidumbre para congrio dorado (Genypterus blacodes Schneider, 1801) en la zona sur-austral de Chile Estimation of natural mortality and uncertainty in pink cusk-eel (Genypterus blacodes Schneider, 1801) in southern Chile

    OpenAIRE

    Rodrigo Wiff; Quiroz, J.C.; Vilma Ojeda; Mauricio A Barrientos

    2011-01-01

    El congrio dorado (Genypterus blacodes) es un pez demersal de gran importancia económica en la pesquería multiespecífica y multiflota que opera en la zona sur-austral de Chile (41°28'-57°00'S). Desde principio de los años noventas se consideró para efectos de la evaluación poblacional la existencia de un único stock. Sin embargo, varios antecedentes relacionados con la historia de vida y demografía han conducido a que, desde el año 2005, la evaluación de esta especie se realice bajo dos stock...

  18. Isotopic evolution of aqueous sulphate in northern Chile water

    International Nuclear Information System (INIS)

    Full text: The extremely arid condition of northern Chile is the main obstacle to the present and future development of urban centres and economic activities in the region. The existing water resources are scarce. During the last decade, isotope techniques have been applied to investigate aspects such as the origin and residence time of the groundwater, these being extremely important for water development and water management. This paper presents 18O and 34S data in aqueous sulphate, as well as 18O, 2H, and 3H from springs, rivers and groundwater samples of the Pampa del Tamarugal and Salar de Llamara basins. The principal aim of this study was to investigate the isotope evolution of the sulphate, the origin of the sulphur, the groundwater flow path, and the possibility of using the 18O of the sulphate as a tracer for estimation of the residence time of the groundwater. Springs that have their recharge area in the high Altiplano (Salar del Huasco basin) show δ values between +5.0 per mille and +6.0 per mille for the 18O and +5.0 per mille and +9.0 per mille for the 34S isotope. Springs from lower altitude, show an isotope content between + 8.6 per mille and + 10.6 per mille for 18O and +7.4 per mille and + 11.7 per mille for 34S. The groundwaters in the Pampa aquifers, based on their hydrogen and oxygen isotope composition, are associated with different recharge areas. However, these waters show an isotope range for the sulphate similar to .he one of the springs, and no clear relationships are observed between isotope content, flow path and residence time. This pattern could be related to the poorly defined aquifer systems present in the Pampa. The Llamara groundwaters have a uniform isotope content and are the most enriched in the region (δ18O = -6.0 per mille and δ2H = -50 per mille). The isotope composition of their sulphate compares well with the Pampa groundwater, indicating a similar sulphate source. The isotope composition of gypsum deposits in the

  19. Energy and Mass Balance At Gran Campo Nevado, Patagonia, Chile

    Science.gov (United States)

    Schneider, C.; Kilian, R.; Casassa, G.

    The Gran Campo Nevado (GCN) Ice Cap on Peninsula Muñoz Gamero, Chile, is lo- cated in the southernmost part of the Patagonian Andes at 53S. It comprises an ice cap and numerous outlet glaciers which mostly end in proglacial lakes at sea level. The total ice covered area sums up to approximately 250 km2. GCN forms the only major ice body between the Southern Patagonian Icefield and the Street of Magallan. Its almost unique location in the zone of the all-year westerlies makes it a region of key interest in terms of glacier and climate change studies of the westwind zone of the Southern Hemisphere. Mean annual temperature of approximately +5C at sea level and high precipitation of about 8.000 mm per year lead to an extreme turn-over of ice mass from the accumulation area of the GCN Ice Cap to the ablation areas of the outlet glaciers. Since October 1999 an automated weather station (AWS) is run continuously in the area at Bahia Bahamondes for monitoring climate parameters. From February to April 2000 an additional AWS was operated on Glaciar Lengua a small outlet glacier of GCN to the north-west. Ablation has been measured at stakes during the same pe- riod. The aim of this study, was to obtain point energy and mass balance on Glaciar Lengua. The work was conducted as part of the international and interdisciplinary working group SGran Campo NevadoT and supported by the German Research Foun- & cedil;dation (DFG). Energy balance was calculated using the bulk approach formulas and calibrated to the measured ablation. It turns out, that sensible heat transfer is the major contribution to the energy balance. Since high cloud cover rates prevail, air tempera- ture is the key factor for the energy balance of the glacier. Despite high rain fall rates, energy input from rain fall is of only minor importance to the overall energy balance. From the energy balance computed, it was possible to derive summer-time degree-day factors for Glaciar Lengua. With data from the nearby

  20. Lake Andes National Wildlife Refuge: Annual narrative report: Calendar year 1983

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Lake Andes NWR, Lake Andes WMD, and Karl E. Mundt NWR outlines Refuge accomplishments during the 1983 calendar year. The report...

  1. Lake Andes National Wildlife Refuge: Annual narrative report: Calendar year 1981

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Lake Andes NWR, Lake Andes WMD, and Karl E. Mundt NWR outlines Refuge accomplishments during the 1981 calendar year. The report...

  2. Lake Andes National Wildlife Refuge: Annual narrative report: Calendar year 1982

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Lake Andes NWR, Lake Andes WMD, and Karl E. Mundt NWR outlines Refuge accomplishments during the 1982 calendar year. The report...

  3. Lake Andes National Wildlife Refuge: Annual narrative report: Calendar year 1984

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Lake Andes NWR, Lake Andes WMD, and Karl E. Mundt NWR outlines Refuge accomplishments during the 1984 calendar year. The report...

  4. Lake Andes National Wildlife Refuge: Annual narrative report: Calendar year 1985

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Lake Andes NWR, Lake Andes WMD, and Karl E. Mundt NWR outlines Refuge accomplishments during the 1985 calendar year. The report...

  5. Lake Andes National Wildlife Refuge: Annual narrative report: Calendar year 1989

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Lake Andes NWR, Lake Andes WMD, and Karl E. Mundt NWR outlines Refuge accomplishments during the 1989 calendar year. The report...

  6. Lake Andes National Wildlife Refuge: Annual narrative report: Calendar year 1986

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Lake Andes NWR, Lake Andes WMD, and Karl E. Mundt NWR outlines Refuge accomplishments during the 1986 calendar year. The report...

  7. Lake Andes National Wildlife Refuge: Annual narrative report: Calendar year 1988

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Lake Andes NWR, Lake Andes WMD, and Karl E. Mundt NWR outlines Refuge accomplishments during the 1988 calendar year. The report...

  8. Lake Andes National Wildlife Refuge: Annual narrative report: Calendar year 1987

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Lake Andes NWR, Lake Andes WMD, and Karl E. Mundt NWR outlines Refuge accomplishments during the 1987 calendar year. The report...

  9. Lake Andes National Wildlife Refuge : Annual narrative report : Calendar year 1992

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Lake Andes NWR, Karl Mundt NWR, and Lake Andes WMD outlines Refuge accomplishments during the 1992 calendar year. The report begins...

  10. Lake Andes National Wildlife Refuge Complex : Annual narrative report : Calendar year 1993

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Lake Andes NWR, Karl Mundt NWR, and Lake Andes WMD outlines Refuge accomplishments during the 1993 calendar year. The report begins...

  11. Lake Andes National Wildlife Refuge Complex : Annual narrative report : Calendar year 1991

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Lake Andes NWR, Karl Mundt NWR, and Lake Andes WMD outlines Refuge accomplishments during the 1991 calendar year. The report begins...

  12. Lake Andes National Wildlife Refuge: Annual narrative report: Calendar year 1990

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Lake Andes NWR, Lake Andes WMD, and Karl E. Mundt NWR outlines Refuge accomplishments during the 1990 calendar year. The report...

  13. A satellite geodetic survey of large-scale deformation of volcanic centres in the central Andes

    Science.gov (United States)

    Pritchard, Matthew E.; Simons, Mark

    2002-07-01

    Surface deformation in volcanic areas usually indicates movement of magma or hydrothermal fluids at depth. Stratovolcanoes tend to exhibit a complex relationship between deformation and eruptive behaviour. The characteristically long time spans between such eruptions requires a long time series of observations to determine whether deformation without an eruption is common at a given edifice. Such studies, however, are logistically difficult to carry out in most volcanic arcs, as these tend to be remote regions with large numbers of volcanoes (hundreds to even thousands). Here we present a satellite-based interferometric synthetic aperture radar (InSAR) survey of the remote central Andes volcanic arc, a region formed by subduction of the Nazca oceanic plate beneath continental South America. Spanning the years 1992 to 2000, our survey reveals the background level of activity of about 900 volcanoes, 50 of which have been classified as potentially active. We find four centres of broad (tens of kilometres wide), roughly axisymmetric surface deformation. None of these centres are at volcanoes currently classified as potentially active, although two lie within about 10km of volcanoes with known activity. Source depths inferred from the patterns of deformation lie between 5 and 17km. In contrast to the four new sources found, we do not observe any deformation associated with recent eruptions of Lascar, Chile.

  14. A satellite geodetic survey of large-scale deformation of volcanic centres in the central Andes.

    Science.gov (United States)

    Pritchard, Matthew E; Simons, Mark

    2002-07-11

    Surface deformation in volcanic areas usually indicates movement of magma or hydrothermal fluids at depth. Stratovolcanoes tend to exhibit a complex relationship between deformation and eruptive behaviour. The characteristically long time spans between such eruptions requires a long time series of observations to determine whether deformation without an eruption is common at a given edifice. Such studies, however, are logistically difficult to carry out in most volcanic arcs, as these tend to be remote regions with large numbers of volcanoes (hundreds to even thousands). Here we present a satellite-based interferometric synthetic aperture radar (InSAR) survey of the remote central Andes volcanic arc, a region formed by subduction of the Nazca oceanic plate beneath continental South America. Spanning the years 1992 to 2000, our survey reveals the background level of activity of about 900 volcanoes, 50 of which have been classified as potentially active. We find four centres of broad (tens of kilometres wide), roughly axisymmetric surface deformation. None of these centres are at volcanoes currently classified as potentially active, although two lie within about 10 km of volcanoes with known activity. Source depths inferred from the patterns of deformation lie between 5 and 17 km. In contrast to the four new sources found, we do not observe any deformation associated with recent eruptions of Lascar, Chile. PMID:12110886

  15. Genesis of adakite-like lavas of Licancabur volcano (Chile—Bolivia, Central Andes)

    Science.gov (United States)

    Figueroa, Oscar; Déruelle, Bernard; Demaiffe, Daniel

    2009-04-01

    The Licancabur volcano is located on the Bolivia—Chile Altiplano (Central Andes). The lavas are andesites and dacites. Numerous mineralogic features attest that magma mixing occurred. Andesites have concave (spoon-shaped) REE patterns whereas dacites have steep slopes. A spectacular crossover of patterns occurs with increasing SiO 2. Most geochemical discrimination criteria of adakites are satisfied by Licancabur dacites, except their high Sr-isotope compositions (> 0.7075). For the genesis of the Licancabur adakite-like lavas, a four-step model is proposed: (1) partial melting (5 to 10 wt %) of a subducted altered oceanic crust; (2) hybridation (< 10 wt %) of the magmas with melts derived from the overlying lithospheric mantle; (3) contamination (≈ 1 wt %) of these hybrid magmas by TTG-type granodiorites of the Archean lower continental crust (with present-day Sr-isotope ratios ≈ 0.820); (4) evolution and differentiation by crystal fractionation (< 6 wt %) and magma mixing at upper crustal levels.

  16. Quantitative Temperature Reconstructions from Holocene and Late Glacial Lake Sediments in the Tropical Andes using Chironomidae (non-biting midges)

    Science.gov (United States)

    Matthews-Bird, F.; Gosling, W. D.; Brooks, S. J.; Montoya, E.; Coe, A. L.

    2014-12-01

    Chironomidae (non-biting midges) is a family of two-winged aquatic insects of the order Diptera. They are globally distributed and one of the most diverse families within aquatic ecosystems. The insects are stenotopic, and the rapid turnover of species and their ability to colonise quickly favourable habitats means chironomids are extremely sensitive to environmental change, notably temperature. Through the development of quantitative temperature inference models chironomids have become important palaeoecological tools. Proxies capable of generating independent estimates of past climate are crucial to disentangling climate signals and ecosystem response in the palaeoecological record. This project has developed the first modern environmental calibration data set in order to use chironomids from the Tropical Andes as quantitative climate proxies. Using surface sediments from c. 60 lakes from Bolivia, Peru and Ecuador we have developed an inference model capable of reconstructing temperatures, with a prediction error of 1-2°C, from fossil assemblages. Here we present the first Lateglacial and Holocene chironomid-inferred temperature reconstructions from two sites in the tropical Andes. The first record, from a high elevation (4153 m asl) lake in the Bolivian Andes, shows persistently cool temperatures for the past 15 kyr, punctuated by warm episodes in the early Holocene (9-10 kyr BP). The chironomid-inferred Holocene temperature trends from a lake sediment record on the eastern Andean flank of Ecuador (1248 m asl) spanning the last 5 millennia are synchronous with temperature changes in the NGRIP ice core record. The temperature estimates suggest along the eastern flank of the Andes, at lower latitudes (~1°S), climate closely resemble the well-established fluctuations of the Northern Hemisphere for this time period. Late-glacial climate fluctuations across South America are still disputed with some palaeoecological records suggesting evidence for Younger Dryas

  17. The fruit fly programme in Chile

    International Nuclear Information System (INIS)

    Full text: country. In fact, no species of the genera Ceratitis, Bactrocera, Anastrepha, Dacus and Toxotrypana exist in the country. This programme uses the Fruit fly National Detection System, which includes detection of the pest by trapping and fruit sampling in different areas located between the I and XI Regions of the country. This system is approved by the Chilean trade partners on the basis of the fruit fly-free recognition. For the Chilean fresh fruit exports, this is an important advantage, because there is no need to apply quarantine treatments or any other restriction measure. Chile has also a huge fruit industry, whose export revenues last season reached USD 1,900 million. This fact has permitted to undertake continuously a big effort to maintain that phytosanitary condition. Since Chile is the only fruit-fly free Latin American country, it has to face a continuous biological pressure of fruit flies, mainly C. capitata, to invade its territory. But the country has also some important advantages to prevent flies migrating due to its natural isolation. These natural barriers are the Los Andes ranges in the east, thousands of kilometers of desert in the north, the Pacific Ocean in the west and finally an extremely cold, sub polar climate in the south. This isolation has led to the NPPO officials to believe that the passive spread, through smuggling and hidden fruit in passenger's baggage, to be the most likely source of fruit fly entries. Because of that, Chile has a very strict quarantine system with border control stations at every point of entry. The only exception to the mentioned isolation is Arica Province on the border with Peru. There, SAG applies an area-wide preventative approach through the rearing and release of sterile insects, as well as bait spraying in the border area, which is mainly desert, but has some 'green spots' that allow the fly to alight for resting and feeding. Additionally, through bi-national agreements, common activities are

  18. complejidad en Chile

    Directory of Open Access Journals (Sweden)

    Miguel Alejandro Bustamante-Ubilla

    2015-01-01

    Full Text Available El presente estudio tiene por objetivo caracterizar el clima organizacional al interior de 2 hospitales dealta complejidad de Chile, determinando las dimensiones más y menos influyentes. Para su desarrollose aplicó un cuestionario que consta de 71 variables agrupadas en 14 dimensiones a una muestra de561 funcionarios. La interpretación de los resultados se realizó a través del análisis del valor prome-dio estandarizado y su confiabilidad ratificada mediante el alfa de Cronbach. A partir de lo anterior, sedeterminó que las dimensiones que influyen por encima del promedio fueron: identidad, motivaciónlaboral y responsabilidad; en tanto que las dimensiones que muestran un nivel de impacto por debajodel promedio resultaron ser: equipo y distribución de personas y material, administración del conflictoy comunicación.© 2015 Universidad ICESI. Publicado por Elsevier España, S.L.U. Este es un artículo Open Access bajo lalicencia CC BY (http://creativecommons.org/licenses/by/4.0/.

  19. PARASITOS DE LOS ANIMALES DOMESTICOS EN CHILE

    OpenAIRE

    HECTOR ALCAINO; TEXIA GORMAN

    1999-01-01

    PARASITES OF DOMESTIC ANIMALS IN CHILE An up-to-date list of the parasites that have been identified in horses, cattle, sheep, goats, llamas, alpacas, pigs, dogs, cats, rabbits, chickens and pigeons in Chile, according to the studies performed at the University of Chile and other Universities and Institutes.

  20. China and Chile Signing Free Trade Agreement

    Institute of Scientific and Technical Information of China (English)

    Shen; Danyang

    2005-01-01

      Mr. Bo Xilai, Minister of Commerce of China, and Mr.Walker, Foreign Minister of Chile, signed the China-Chile FTA on behalf of their respective government on November 18, 2005. Chinese President Hu Jintao and Chile President Lagos attended the signing ceremony, according to a press release on the website of Network Center of MOFCOM.……

  1. China and Chile Signing Free Trade Agreement

    Institute of Scientific and Technical Information of China (English)

    Shen Danyang

    2005-01-01

    @@ Mr. Bo Xilai, Minister of Commerce of China, and Mr.Walker, Foreign Minister of Chile, signed the China-Chile FTA on behalf of their respective government on November 18, 2005. Chinese President Hu Jintao and Chile President Lagos attended the signing ceremony, according to a press release on the website of Network Center of MOFCOM.

  2. PARASITOS DE LOS ANIMALES DOMESTICOS EN CHILE

    Directory of Open Access Journals (Sweden)

    HECTOR ALCAINO

    1999-01-01

    Full Text Available PARASITES OF DOMESTIC ANIMALS IN CHILE An up-to-date list of the parasites that have been identified in horses, cattle, sheep, goats, llamas, alpacas, pigs, dogs, cats, rabbits, chickens and pigeons in Chile, according to the studies performed at the University of Chile and other Universities and Institutes.

  3. Contrasting response of glacierized catchments in the Central Himalaya and the Central Andes to climate change

    Science.gov (United States)

    Ragettli, Silvan; Pellicciotti, Francesca; Immerzeel, Walter

    2015-04-01

    The Andes of South America and the Himalaya in high-mountain Asia are two regions where advanced simulation models are of vital importance to anticipate the impacts of climate change on water resources. The two mountain systems hold the largest ice masses outside the polar regions. Major rivers originate here and downstream regions are densely populated. In the long run, glacier recession generates concerns about the sustainability of summer runoff. This study benefits from recent efforts of carefully planned short-term field experiments in two headwater catchments in the Central Andes of Chile and in the Central Himalaya in Nepal. The two study catchments contrast in terms of their climate and in the characteristics of their glaciers. A systematic approach is developed, built upon the available local data, to reduce the predictive uncertainty of a state-of-the-art glacio-hydrological model used for the projection of 21st century glacier changes and catchment runoff. The in-situ data are used for model development and step-wise, multivariate parameter calibration. Catchment runoff and remotely sensed MODIS and Landsat snow cover are used for model validation. The glacio-hydrological model simulates the water cycle with a high temporal (hourly time steps) and spatial (100 m grid cells) resolution and accounts for processes typical of both regions like glacier melt under debris cover or mass redistribution through avalanching. Future projections are based on the outputs of twelve stochastically downscaled global climate models for two emission scenarios (RCP 4.5 and RCP 8.5). This is one of the first truly intercomparative modeling studies at the catchment scale across mountain regions of the world to assess and compare future changes in glaciers and snow cover and associated impacts on streamflow production. Both catchments will experience significant glacier mass loss throughout the twenty-first century. However, the trajectories of simulated future runoff and

  4. The Largest Holocene Eruption of the Central Andes Found

    Science.gov (United States)

    Fernandez-Turiel, J.; Rodriguez-Gonzalez, A.; Saavedra, J.; Perez-Torrado, F.; Carracedo, J.; Osterrieth, M.; Carrizo, J.; Esteban, G.

    2013-12-01

    We present new data and interpretation about a major eruption -spreading ˜110 km3 ashes over 440.000 km2- long thought to have occurred around 4200 years ago in the Cerro Blanco Volcanic Complex (CBVC) in NW Argentina. This eruption may be the biggest during the past five millennia in the Central Volcanic Zone of the Andes, and possibly one of the largest Holocene eruptions in the world. The environmental effects of this voluminous eruption are still noticeable, as evidenced by the high content of arsenic and other trace elements in the groundwaters of the Chacopampean Plain. The recognition of this significant volcanic event may shed new light on interpretations of critical changes observed in the mid-Holocene paleontological and archaeological records, and offers researchers an excellent, extensive regional chronostratigraphic marker for reconstructing mid-Holocene geological history over a wide geographical area of South America. More than 100 ashes were sampled in Argentina, Chile and Uruguay during different field campaigns. Ash samples were characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), grain size distributions laser diffraction, and geochemically by electron microprobe (EMPA) and laser ablation-HR-ICP-MS. New and published 14C ages were calibrated to calendar years BP. The age of the most recent CBVC eruption is 4407-4093 cal y BP, indirectly dated by 14C of associated organic sediment within the lower part of a proximal fall deposit of this event (26°53'16.05"S-67°44'48.68"W). This is the youngest record of a major volcanic event in the Southern Puna. This age is consistent with other radiocarbon dates of organic matter in palaeosols underlying or overlying distal ash fall deposits. Based on their products, all of rhyolitic composition, we have distinguished 8 main episodes during the evolution of the most recent CBVC eruption: 1) the eruption began with a white rhyolite lava dome extrusion; 2) followed by a Plinian

  5. Regionalisation of Hydrological Indices to Assess Land-Use Change Impacts in the Tropical Andes

    Science.gov (United States)

    Buytaert, W.; Ochoa Tocachi, B. F.

    2014-12-01

    Andean ecosystems are major water sources for cities and communities located in the Tropical Andes; however, there is a considerable lack of knowledge about their hydrology. Two problems are especially important: (i) the lack of monitoring to assess the impacts of historical land-use and cover change and degradation (LUCCD) at catchment scale, and (ii) the high variability in climatic and hydrological conditions that complicate the evaluation of land management practices. This study analyses how a reliable LUCCD impacts assessment can be performed in an environment of high variability combined with data-scarcity and low-quality records. We use data from participatory hydrological monitoring activities in 20 catchments distributed along the tropical Andes. A set of 46 hydrological indices is calculated and regionalized by relating them to 42 physical catchment properties. Principal Component Analysis (PCA) is performed to maximise available data while minimising redundancy in the sets of variables. Hydrological model parameters are constrained by estimated indices, and different behavioural predictions are assembled to provide a generalised response on which we assess LUCCD impacts. Results from this methodology show that the attributed effects of LUCCD in pair-wise catchment comparisons may be overstated or hidden by different sources of uncertainty, including measurement inaccuracies and model structural errors. We propose extrapolation and evaluation in ungauged catchments as a way to regionalize LUCCD predictions and to provide statistically significant conclusions in the Andean region. These estimations may deliver reliable knowledge to evaluate the hydrological impact of different watershed management practices.

  6. ESTIMACIÓN DE COSTOS MEDIOS DE PRODUCCIÓN DE LECHE EN TRES PREDIOS DE LA REGIÓN DEL MAULE, CHILE. ESTUDIO DE CASOS Estimate of Average Production Costs for Three Dairies of Maule Region, Chile: A Case Study

    OpenAIRE

    Germán Lobos A; Mavel Miño C.; Erika González M.; Anita Prizant S.

    2001-01-01

    Se estimaron costos medios mensuales para el año 1998 de la producción de leche en tres lecherías ubicadas en la provincia de Linares (35º51’ lat. S. y 71º35’ long. O.), Región del Maule, Chile. Las explotaciones lecheras están asociadas a la empresa PROLECHE S.A., formada con apoyo financiero de la Corporación de Fomento de la Producción (CORFO) para la gestión asociativa. La tasa de descuento relevante fue estimada utilizando el Modelo de Valorización de Activos de Capital (CAPM) y el Costo...

  7. Craniofacial chronological microdifferentiation of human prehistoric populations of the Azapa valley, northern Chile Microdiferenciación cronológica craneofacial de poblaciones humanas prehistóricas del Valle de Azapa, norte de Chile

    Directory of Open Access Journals (Sweden)

    FRANCISCO ROTHHAMMER

    2002-03-01

    Full Text Available Archeological evidence suggest that the cultural developments occurred in the highlands around lake Titicaca in the Central Andes, exerted influence on the cultural elaborations of the human groups that peopled the valley of Azapa, close to the city of Arica, and the Pacific coast of northern Chile. In this communication we show by means of a distance analysis, that a craniofacial differentiation accompanied the process of cultural evolution in the valley. The biological influence of Tiwanaku is partially reflected in craniofacial morphology, providing preliminary evidence that cultural changes were associated to intermittent gene flow from the highlands, specially during the Alto Ramírez and San Miguel phasesLos desarrollos culturales ocurridos en el altiplano en el área circumtiticaca en los Andes centrales, ejercieron influencia sobre las elaboraciones culturales de los grupos humanos que poblaban el Valle de Azapa cercano a la ciudad de Arica y la costa del norte de Chile. En esta comunicación presentamos un análisis de distancias que demostró que una diferenciación craniofacial acompaño en el valle el proceso de evolución cultural. La influencia biológica de Tiwanaku se refleja parcialmente en la morfología craniofacial, proporcionando evidencia preliminar de que los cambios culturales en el valle se realizaron acompañados de flujo génico intermitente desde el altiplano, especialmente durante las fases Alto Ramírez y San Miguel

  8. Large slope instabilities in Northern Chile and Southern Peru

    Science.gov (United States)

    Crosta, Giovanni B.; Hermanns, Reginald L.; Valbuzzi, Elena; Frattini, Paolo; Valagussa, Andrea

    2014-05-01

    Deep canyon incision into Tertiary paleosurfaces and large slope instabilities along the canyon flanks characterize the landscape of western slope of the Andes of northern Chile and South Peru. This area belongs to the Coastal Escarpment and Precordillera and is formed by coarse-grained clastic and volcanoclastic formations. The area is characterized by intense seismicity and long-term hyperaridity (Atacama Desert). Landslides along the canyon flanks affect volumes generally up to 1 km3 and locally evolved in large rock avalanches. We prepared a landslide inventory covering an area of about 30,000 km2, extending from Iquique (Chile) to the South and Tacna (Peru) to the North. A total of 606 landslides have been mapped in the area by use of satellite images and direct field surveys, prevalently including large phenomena. The landslides range from 1 10-3 km2 to 464 km2 (Lluta landslide). The total landslide area, inclusive of the landslide scarp and of the deposit, amounts to about 2,130 km2 (about 7% of the area). The mega landslides can be classified as large block slides that can evolve in large rock avalanches (e.g. Minimini landslide). Their initiation seems to be strongly associated to the presence of secondary faults and large fractures transversal to the slope. These landslides show evidence suggesting a re-incision by the main canyon network. This seems particularly true for the Lluta collapse where the main 'landslide' mass is masked or deleted by the successive erosion. Other landslides have been mapped along the Coastal Escarpment and some of the major tectonic escarpments with an E-W trend. We examined area-frequency distributions of landslides by developing logarithmically binned, non-cumulative size frequency distributions that report frequency density as a function of landslide planar area A. The size frequency distribution presents a strong undersampling for smaller landslides, due to the extremely old age of the inventory. For landslides larger than

  9. Possible future lakes in the Andes of Peru

    Science.gov (United States)

    Colonia, Daniel; Haeberli, Wilfried; Torres, Judith; Giraldez, Claudia; Schauwecker, Simone; Santiago, Alexzander; Cochachin, Alejo; Huggel, Christian

    2015-04-01

    volume of the new major lakes is estimated at about 60-65 million m³. This corresponds to about half a percent of the total glacier volume remaining in the year 2003 and estimated at 15.69 km³. This relatively small percentage is due to the fact that most flat glacier parts where bed-overdeepenings can be expected have already disappeared. The same methodology is now being applied to the main glacierized Cordilleras of Perú. The data obtained will provide important information for responsible governmental authorities related to freshwater resources, hazard prevention, energy production and landscape diversity in view of taking immediate actions for water resource management and disaster risk management. These aspects will be critical for the success of any efforts to adapt to the impacts of climate change in the Andes of Peru.

  10. Apacheta, a new geothermal prospect in Northern Chile

    Energy Technology Data Exchange (ETDEWEB)

    Urzua, Luis; Powell, Tom; Cumming, William B.; Dobson, Patrick

    2002-05-24

    The discovery of two high-temperature fumaroles, with gas geochemistry compatible with an economic geothermal system, established Apacheta as one of the most attractive geothermal exploration prospects in northern Chile. These remote fumaroles at 5,150 m elevation were first sampled in 1999 by ENAP and its partners, following up on the reports of a CODELCO water exploration well that flowed small amounts of dry steam at 4,540 m elevation in the valley 4.5 km east of the fumaroles. The prospect is associated with a Plio-Pleistocene volcanic complex located within a NW-trending graben along the axis of the high Andes. The regional water table is 4,200 masl. There are no hot springs, just the 88 degrees C steam well and the 109 degrees and 118 degrees C fumaroles with gas compositions that indicate reservoir temperatures of greater than or equal to 250 degrees C, using a variety of gas geothermometers. An MT-TDEM survey was completed in 2001-2002 by Geotermica del Norte (SDN), an ENAP-C ODELCO partnership, to explore the Apacheta geothermal concession. The survey results indicated that base of the low resistivity clay cap has a structural apex just west of the fumaroles, a pattern typically associated with shallow permeability within a high temperature geothermal resource. SGN plans to drill at least one exploration well in 2002-03 to characterize a possible economic resource at Apacheta.

  11. Water governance in Chile: Availability, management and climate change

    Science.gov (United States)

    Valdés-Pineda, Rodrigo; Pizarro, Roberto; García-Chevesich, Pablo; Valdés, Juan B.; Olivares, Claudio; Vera, Mauricio; Balocchi, Francisco; Pérez, Felipe; Vallejos, Carlos; Fuentes, Roberto; Abarza, Alejandro; Helwig, Bridget

    2014-11-01

    Chile has a unique geography that provides an extraordinary variety of climatic conditions and availability of water resources. The objective of this manuscript was to describe and analyze the spatial and temporal distribution patterns, as well as the management of water resources, along a country with a narrow distance from the Andes Mountains to the Pacific Ocean. This presents challenges to water governance from data collection and analysis perspectives, and for administration of the resource. The Water Resources Directorate (Dirección General de Aguas, DGA), is the federal government organization in charge of the water resources of the country. The DGA and other relevant public and private institutions are examined in terms of competition and conflict resolution across different scales and levels of interaction associated with water resources governance. Both monitoring stations (rainfall, streamflow, water quality, groundwater, sediment and snowfall), and the Chilean management and legislation of water resources are also analyzed. Finally, the success (or lack) of the national administration to upgrade its monitoring stations and equalize water resources distribution throughout the country is discussed including the influence of climate change on data collection, and decision making across different scales of water governance.

  12. Prediction of extreme floods in the Central Andes by means of Complex Networks

    Science.gov (United States)

    Boers, Niklas; Bookhagen, Bodo; Barbosa, Henrique; Marwan, Norbert; Kurths, Jürgen; Marengo, Jose

    2014-05-01

    Based on a non-linear synchronisation measure and complex network theory, we present a novel framework for the prediction of extreme events of spatially embedded, interrelated time series. This method is general in the sense that it can be applied to any type of spatially sampled time series with significant interrelations, ranging from climate observables to biological or stock market data. In this presentation, we apply our method to extreme rainfall in South America and show how this leads to the prediction of more than 60% (90% during El Niño conditions) of extreme rainfall events in the eastern Central Andes of Bolivia and northern Argentina, with only 1% false alarms. From paleoclimatic to decadal time scales, the Central Andes continue to be subject to pronounced changes in climatic conditions. In particular, our and past work shows that frequency as well as magnitudes of extreme rainfall events have increased significantly during past decades, calling for a better understanding of the involved climatic mechanisms. Due to their large spatial extend and occurrence at high elevations, these extreme events often lead to severe floods and landslides with disastrous socioeconomic impacts. They regularly affect tens of thousands of people and produce estimated costs of the order of several hundred million USD. Alongside with the societal value of predicting natural hazards, our study provides insights into the responsible climatic features and suggests interactions between Rossby waves in polar regions and large scale (sub-)tropical moisture transport as a driver of subseasonal variability of the South American monsoon system. Predictable extreme events result from the propagation of extreme rainfall from the region of Buenos Aires towards the Central Andes given characteristic atmospheric conditions. Our results indicate that the role of frontal systems originating from Rossby waves in polar latitudes is much more dominant for controlling extreme rainfall in

  13. The biomethane potential in Chile

    International Nuclear Information System (INIS)

    Within the last decade natural gas gained considerable importance in Chile. The contribution of natural gas within the energy system will increase in the future by predicted 3.6% annually until the year 2015. Due to limited resources within its own country, the energy system of Chile depends on natural gas imports preferential from Argentina. Therefore, the aim of several stakeholders from policy and industry is to reduce the share of imported primary energy within the overall energy system. In order to reach this goal, the use of domestic resources and particularly the utilisation of biomass as one of the most important renewable sources of energy in Chile could play an important role. Against this background, the goal of this paper is the analysis of the technical potentials of biomethane as a substitute for natural gas. For the production of biomethane the anaerobic or bio-chemical (i.e. Biogas) as well as the thermo-chemical conversion pathways (i.e. Bio-SNG) are considered. The results of this analysis show that biomass converted to biomethane is a promising energy provision option for Chile and it contributes to the reduction of greenhouse gas emissions

  14. Corporate Governance Country Assessment : Chile

    OpenAIRE

    World Bank

    2003-01-01

    Chile's equity market is fairly large and successful. The market capitalization of the 249 listed firms represented 89 percent of GDP at year-end, 2001. Corporate ownership is concentrated and pyramid structures are common. Business groups/conglomerates are the predominant corporate form. Institutional investors, especially pension funds, are active equity investors. The Securities Market ...

  15. Socialisme i Chile efter Pinochet

    DEFF Research Database (Denmark)

    Cristoffanini, Pablo Rolando

    2008-01-01

    Chile bliver ofte præsenteret som et paradigme for resten af det latinamerikanske kontinent: Et land med høj økonomisk vækst og politisk stabilitet. Landet har endda haft to socialistiske præsidenter siden 2000, den sidste den første kvindelige præsident. Succeshistorien har en bagside: De social...

  16. Preliminary Results From the CAUGHT Experiment: Investigation of the North Central Andes Subsurface Using Receiver Functions and Ambient Noise Tomography

    Science.gov (United States)

    Ryan, J. C.; Ward, K. M.; Porter, R. C.; Beck, S. L.; Zandt, G.; Wagner, L. S.; Minaya, E.; Tavera, H.

    2011-12-01

    Jamie Ryan, Kevin M. Ward, Ryan Porter, Susan Beck, George Zandt, Lara Wagner, Estela Minaya, and Hernando Tavera The University of Arizona The University of North Carolina San Calixto Observatorio, La Paz, Bolivia IGP, Lima, Peru In order to investigate the interplay between crustal shortening, lithospheric removal, and surface uplift we have deployed 50 broadband seismometers in northwestern Bolivia and southern Peru as part of the interdisciplinary Central Andean Uplift and Geodynamics of High Topography (CAUGHT) project. The morphotectonic units of the central Andes from west to east, consist of the Western Cordillera, the active volcanic arc, the Altiplano, an internally drained basin (~4 km elevation), the Eastern Cordillera, the high peaks (~6 km elevation) of an older fold and thrust belt, the Subandean zone, the lower elevation active fold and thrust belt, and the foreland Beni basin. Between northwestern Bolivia and southern Peru, the Altiplano pinches out north of Lake Titicaca as the Andes narrow northward. The CAUGHT seismic instruments were deployed between 13° to 18° S latitudes to investigate the crust and mantle lithosphere of the central Andes in this transitional zone. In northwest Bolivia, perpendicular to the strike of the Andes, there is a total of 275 km of documented upper crustal shortening (15° to 17°S) (McQuarrie et al, 2008). Associated with the shortening is crustal thickening and possibly lithospheric removal as the thickening lithospheric root becomes unstable. An important first order study is to compare upper crustal shortening estimates with present day crustal thickness. To estimate crustal thickness, we have calculated receiver functions using an iterative deconvolution method and used common conversion point stacking along the same profile as the geologically based shortening estimates. In our preliminary results, we observed a strong P to S conversion corresponding to the Moho at approximately 60-65 km depth underneath the

  17. Carbon stabilization mechanisms in soils in the Andes

    Science.gov (United States)

    Jansen, Boris; Cammeraat, Erik

    2015-04-01

    The volcanic ash soils of the Andes contain very large stocks of soil organic matter (SOM) per unit area. Consequently, they constitute significant potential sources or sinks of the greenhouse gas CO2. Climate and/or land use change potentially have a strong effect on these large SOM stocks. To clarify the role of chemical and physical stabilisation mechanisms in volcanic ash soils in the montane tropics, we investigated carbon stocks and stabilization mechanisms in the top- and subsoil along an altitudinal transect in the Ecuadorian Andes. The transect encompassed a sequence of paleosols under forest and grassland (páramo), including a site where vegetation cover changed in the last century. We applied selective extraction techniques, performed X-ray diffraction analyses of the clay fraction and estimated pore size distributions at various depths in the top- and subsoil along the transect. In addition, from several soils the molecular composition of SOM was further characterized with depth in the current soil as well as the entire first and the top of the second paleosol using GC/MS analyses of extractable lipids and Pyrolysis-GC/MS analyses of bulk organic matter. Our results show that organic carbon stocks in the mineral soil under forest a páramo vegetation were roughly twice as large as global averages for volcanic ash soils, regardless of whether the first 30cm, 100cm or 200cm were considered. We found the carbon stabilization mechanisms involved to be: i) direct stabilization of SOM in organo-metallic (Al-OM) complexes; ii) indirect protection of SOM through low soil pH and toxic levels of Al; and iii) physical protection of SOM due to a very high microporosity of the soil (Tonneijck et al., 2010; Jansen et al. 2011). When examining the organic carbon at a molecular level, interestingly we found extensive degradation of lignin in the topsoil while extractable lipids were preferentially preserved in the subsoil (Nierop and Jansen, 2009). Both vegetation

  18. 2010 Maule, Chile Images

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — As of May 2010, the number of confirmed deaths stood at 521, with 56 persons still missing. Estimates of economic damage are around $30 billion. According to...

  19. Price elasticity of demand for toll roads in Chile

    OpenAIRE

    Rodrigo Saens; Germán Lobos

    2013-01-01

    The efficiency of a road pricing scheme to optimize the use of transport infrastructure depends on the available information regarding the price elasticity of demand for bridges, tunnels and highways. The aim of this paper is to estimate the price elasticity of demand for toll roads in Chile using the seemingly unrelated regressions (SUR) method and a panel of 48 monthly data drawn from 21 toll plazas (48 x 21). Our results show that, even when controlling for gasoline prices and economic act...

  20. Back-Arc Extension in the Southern Andes: A Review and Critical Reappraisal

    Science.gov (United States)

    Dalziel, I. W. D.

    1981-03-01

    The interpretation that the mafic 'rocas verdes' (green rocks) complex of the southern Andes represents part of the uplifted floor of a Late Jurassic to Early Cretaceous back-arc basin has proved particularly useful in understanding the geological evolution of the southern Andes, the north Scotia Ridge and the Antarctic Peninsula. Clear field evidence of the back-arc setting of the 'rocas verdes' gabbro-sheeted dyke - pillow lava ophiolitic assemblages has encouraged fruitful petrological and geochemical comparison with mid-ocean ridge and marginal basin basalts, other onshore ophiolite complexes, and Archaean greenstone belts. Uncertainty still surrounds estimates of the original width and depth of the basin, as well as the proportion of new mafic crust, compared with relict sialic crust, in the basin floor. These questions are unresolved, owing mainly to the considerable Lower Cretaceous turbiditic basin infill and the effects of mid-Cretaceous compressional deformation. While the field relations clearly indicate that the 'rocas verdes' basin is not an older piece of ocean floor 'trapped' behind a volcanic arc, it is not yet clear whether the basin is directly subduction-related or falls in the category of back-arc 'leaky transforms' like the proto-Gulf of California or apparent 'rip-off' features like the Andaman Sea.

  1. Comparative Phylogeography of Direct-Developing Frogs (Anura: Craugastoridae: Pristimantis) in the Southern Andes of Colombia

    Science.gov (United States)

    García-R, Juan C.; Crawford, Andrew J.; Mendoza, Ángela María; Ospina, Oscar; Cardenas, Heiber; Castro, Fernando

    2012-01-01

    The Andes of South America hosts perhaps the highest amphibian species diversity in the world, and a sizable component of that diversity is comprised of direct-developing frogs of the genus Pristimantis (Anura: Craugastoridae). In order to better understand the initial stages of species formation in these frogs, this study quantified local-scale spatial genetic structuring in three species of Pristimantis. DNA sequences of two mitochondrial gene fragments (16S and COI) were obtained from P. brevifrons, P. palmeri and P. jubatus at different locations in the Cordillera Occidental. We found high levels of genetic diversity in the three species, with highly structured populations (as measured by FST) in P. brevifrons and P. palmeri while P. jubatus showed panmixia. Large effective population sizes, inferred from the high levels of genetic diversity, were found in the three species and two highly divergent lineages were detected within P. jubatus and P. palmeri. Estimated divergence times among populations within P. brevifrons and P. palmeri coincide with the Pleistocene, perhaps due to similar responses to climatic cycling or recent geological history. Such insights have important implications for linking alpha and beta diversity, suggesting regional scale patterns may be associated with local scale processes in promoting differentiation among populations in the Andes. PMID:23049941

  2. Climate variability of the tropical Andes since the late Pleistocene

    Directory of Open Access Journals (Sweden)

    A. Bräuning

    2009-10-01

    Full Text Available Available proxy records witnessing palaeoclimate of the tropical Andes are comparably scarce. Major implications of palaeoclimate development in the humid and arid parts of the Andes are briefly summarized. The long-term behaviour of ENSO has general significance for the climatic history of the Andes due to its impact on regional circulation patterns and precipitation regimes, therefore ENSO history derived from non-Andean palaeo-records is highlighted. Methodological constraints of the chronological precision and the palaeoclimatic interpretation of records derived from different natural archives, such as glacier sediments and ice cores, lake sediments and palaeo-wetlands, pollen profiles and tree rings are addressed and complementary results concerning former climatic conditions are discussed in terms of possible implications of former atmospheric circulation patterns and main climatic forcing factors. During the last years, increasing tree-ring information is getting available from the tropical Andes, providing high-resolution climate-sensitive records covering the past centuries for the study of climate variability.

  3. Excess Returns and Systemic Risk for Chile and Mexico Excess Returns and Systemic Risk for Chile and Mexico

    OpenAIRE

    McNelis, Paul D.; Guay C. Lim

    2000-01-01

    This paper is concerned with excess returns in the equity markets and the evolution of systemic risk in Chile and Mexico during the years 1989-1998, a period of financial openness, policy reform and crisis. A time varying generalised autoregressive conditional heteroscedastic in mean framework is used to estimate progressively more complex models of risk. They include the univariate own volatily model, the bivariate market pricing model, and the trivariate intertemporal asset pricing model. T...

  4. Lithospheric scale model of Merida Andes, Venezuela (GIAME Project)

    Science.gov (United States)

    Schmitz, M.; Orihuela, N. D.; Klarica, S.; Gil, E.; Levander, A.; Audemard, F. A.; Mazuera, F.; Avila, J.

    2013-05-01

    Merida Andes (MA) is one of the most important orogenic belt in Venezuela and represents the northern culmination of South America Andes. During the last 60 years, several models have been proposed to explain the shallow and deep structure, using different geological, geophysical, seismological, geochemical and petrologic concepts; nevertheless, most of them have applied local observation windows, and do not represent the major structure of MA. Therefore, a multidisciplinary research group, coordinated by FUNVISIS, in close cooperation with UCV, ULA and PDVSA, is proposed in order to get the outlined goals in the project entitled GIAME ("Geociencia Integral de los Andes de MErida") was established, which aims to generate a lithospheric scale model and the development of a temporal dynamic model for the MA. As a base for lithospheric investigations of the Merida Andes, we are proposing three wide angle seismic profiles across the orogen on three representative sites, in order to determine the inner structure and its relation with the orogen's gravimetric root. To the date, there are no seismic studies at lithospheric scale which cross MA. The wide angle seismic will be complemented with the re-processing and re-interpretation of existing reflection seismic data, which will allow to establish a relationship between MA and its associated flexural basins (Maracaibo and Barinas-Apure basins). Depending on the results of the VENCORP Project (VENezuelan COntinental Reflection Profiling), which might show some reliable results about crustal features and Moho reflectors along three long seismic profiles at Caribbean Moutain system, a reflection seismic profile across the central portion of MA is proposed. Additional tasks, consisting in MA quaternary deformation studies, using research methods like neotectonics and paleoseismology, georadar, numerical modeling, cinematic GPS, SAR interferometry, thermocronology, detailed studies on regional geology, flexural modeling

  5. The Plutón Diorítico Moat: Mildly alkaline monzonitic magmatism in the Fuegian Andes of Argentina

    Science.gov (United States)

    González Guillot, M.; Escayola, M.; Acevedo, R.; Pimentel, M.; Seraphim, G.; Proenza, J.; Schalamuk, I.

    2009-12-01

    The Plutón Diorítico Moat (Moat Dioritic Pluton, PDM) is the largest of several isolated Cretaceous plutons exposed in the Fuegian Andes of Argentina. It is made of a large variety of rock types ranging from ultramafic bodies (pyroxenites and hornblendites) to syenites. The petrological diversity is thought to have been originated by fractional crystallization of a mantle-derived magma combined with minor assimilation of continental crust (AFC). Its geochemical characteristics indicate a mildly-alkaline monzonitic affinity, contrasting with the typical calc-alkaline plutons of the Southern Patagonian Batholith (PB) to the south, in the Chilean archipelago. The PDM original magma is arc-related and its crystallization, as indicated by the Rb-Sr mineral isochron age of 115 ± 3 Ma, is coeval with some plutons of the PB. Therefore a similar tectonic regime is assumed for the emplacement of these plutonic bodies, both south and north of the Beagle channel. Differences in magma sources and degree of partial melting are inferred to account for the contrasting lithological and geochemical characteristics of the PB and PDM. The data suggest that the original magmas of the PDM were generated at greater depths in the mantle, by a smaller degree of partial melting, compared with the PB. The Barros Arana basalts, exposed to the north in Chile, forming a back-arc volcanic complex, display the same mildly-alkaline shoshonitic affinity, and are considered in this study as the volcanic equivalents of the PDM. All the plutons in the Argentinean Fuegian Andes display similar lithological and geochemical characteristics and are, therefore, grouped in this work under the name of Magmatismo Potásico Fueguino ( Fuegian Potassic Magmatism).

  6. Acuicultura Insostenible en Chile (Unsustainable aquaculture in Chile

    Directory of Open Access Journals (Sweden)

    Sommer, Marcos

    2009-03-01

    Full Text Available ResumenLa acuicultura en Chile sólo será alternativa a la pesca si se consigue llevar su producción a parámetros de sostenibilidad, no solamente económica sino, fundamentalmente, ambiental. Con un esfuerzo dirigido hacia medidas legislativas y de control, e investigación aplicada, podríamos acercarnos a una acuicultura ambientalmente sostenible.

  7. Prevalence of antibodies to hantavirus in health care workers exposed to patients with hantavirus pulmonary syndrome in Temuco, Chile. Prevalencia de anticuerpos anti-hantavirus en personal de salud en contacto directo con pacientes portadores del síndrome pulmonar por hantavirus.: Temuco 1997 a 1999

    OpenAIRE

    Constanza Castillo H; Jovita Mardones M; Eliecer Villagra C

    2000-01-01

    Background: An outbreak of Hantavirus Cardiopulmonary Syndrome (HVCS) caused by the Andes virus, affected Chile since 1995. Antibodies to Hantavirus in health care workers who had cared patients with HVCS in Coyhaique, Argentinean reports and familial clustering of hantaviral illness, raised the possibility of person to person transmission. Familial clustering could occur secondary to a similar exposure to a common infected environment of more than one member of the family. Moreover, the prev...

  8. The high Andes, gene flow and a stable hybrid zone shape the genetic structure of a wide-ranging South American parrot

    Directory of Open Access Journals (Sweden)

    Schaefer H Martin

    2011-06-01

    Full Text Available Abstract Background While the gene flow in some organisms is strongly affected by physical barriers and geographical distance, other highly mobile species are able to overcome such constraints. In southern South America, the Andes (here up to 6,900 m may constitute a formidable barrier to dispersal. In addition, this region was affected by cycles of intercalating arid/moist periods during the Upper/Late Pleistocene and Holocene. These factors may have been crucial in driving the phylogeographic structure of the vertebrate fauna of the region. Here we test these hypotheses in the burrowing parrot Cyanoliseus patagonus (Aves, Psittaciformes across its wide distributional range in Chile and Argentina. Results Our data show a Chilean origin for this species, with a single migration event across the Andes during the Upper/Late Pleistocene, which gave rise to all extant Argentinean mitochondrial lineages. Analyses suggest a complex population structure for burrowing parrots in Argentina, which includes a hybrid zone that has remained stable for several thousand years. Within this zone, introgression by expanding haplotypes has resulted in the evolution of an intermediate phenotype. Multivariate regressions show that present day climatic variables have a strong influence on the distribution of genetic heterogeneity, accounting for almost half of the variation in the data. Conclusions Here we show how huge barriers like the Andes and the regional environmental conditions imposed constraints on the ability of a parrot species to colonise new habitats, affecting the way in which populations diverged and thus, genetic structure. When contact between divergent populations was re-established, a stable hybrid zone was formed, functioning as a channel for genetic exchange between populations.

  9. An InSAR-based survey of volcanic deformation in the central Andes

    Science.gov (United States)

    Pritchard, M. E.; Simons, M.

    2004-02-01

    We extend an earlier interferometric synthetic aperture radar (InSAR) survey covering about 900 remote volcanos of the central Andes (14°-27°S) between the years 1992 and 2002. Our survey reveals broad (10s of km), roughly axisymmetric deformation at 4 volcanic centers: two stratovolcanoes are inflating (Uturuncu, Bolivia, and Hualca Hualca, Peru); another source of inflation on the border between Chile and Argentina is not obviously associated with a volcanic edifice (here called Lazufre); and a caldera (Cerro Blanco, also called Robledo) in northwest Argentina is subsiding. We explore the range of source depths and volumes allowed by our observations, using spherical, ellipsoidal and crack-like source geometries. We further examine the effects of local topography upon the deformation field and invert for a spherical point-source in both elastic half-space and layered-space crustal models. We use a global search algorithm, with gradient search methods used to further constrain best-fitting models. Inferred source depths are model-dependent, with differences in the assumed source geometry generating a larger range of accepted depths than variations in elastic structure. Source depths relative to sea level are: 8-18 km at Hualca Hualca; 12-25 km for Uturuncu; 5-13 km for Lazufre, and 5-10 km at Cerro Blanco. Deformation at all four volcanoes seems to be time-dependent, and only Uturuncu and Cerro Blanco were deforming during the entire time period of observation. Inflation at Hualca Hualca stopped in 1997, perhaps related to a large eruption of nearby Sabancaya volcano in May 1997, although there is no obvious relation between the rate of deformation and the eruptions of Sabancaya. We do not observe any deformation associated with eruptions of Lascar, Chile, at 16 other volcanoes that had recent small eruptions or fumarolic activity, or associated with a short-lived thermal anomaly at Chiliques volcano. We posit a hydrothermal system at Cerro Blanco to explain the

  10. [The epidemiological transition in Chile].

    Science.gov (United States)

    Albalá, C; Vio, F; Robledo, A; Icaza, G

    1993-12-01

    Aiming to describe the place that Chile has in the epidemiological transition, a descriptive study of the changes in demographic and epidemiological profiles of the country during the last 30 years is presented. The important decrease in general and child mortality rates, that has lead to an increase in life expectancy and ageing of the population, is emphasized. A 82% reduction in the proportion of deaths among less than one year old children and a 62% increase in mortality among people 65 years or older is observed. In agreement with these changes, non transmissible chronic diseases appear as the principal cause of mortality (65% of all deaths). However, regarding morbidity, an increase in digestive infectious and sexually transmitted diseases and a decrease in immuno-preventable diseases, excepting measles, is noted. It is concluded that, according to mortality, Chile is in a post transition stage, but there is persistence of some infectious diseases, typical of a pre-transition stage. PMID:8085073

  11. Miedo y represionpolitica en Chile

    OpenAIRE

    Amado M. Padilla; Lillian Comas Díaz

    1987-01-01

    This paper describes a human rights fact-finding mission to Chile concerned with the use of psychological techniques employed in offlcia- Uy sactioned torture and repressíon, Meetings and interviews were conducted with representatives of many organízatíons working with víctima of governrnental repression including the Chílean Psychological Assocíation. Fear and repression wene found to be widespread among all socioeconomic segments of the population. Physical and psychologic...

  12. Interpreting discrepancies between discharge and precipitation in high-altitude area of Chile's Norte Chico region (26-32°S)

    Science.gov (United States)

    Favier, Vincent; Falvey, Mark; Rabatel, Antoine; Praderio, Estelle; López, David

    2009-02-01

    The water resources of high-altitude areas of Chile's semiarid Norte Chico region (26-32°S) are studied using surface hydrological observations (from 59 rain gauges and 38 hydrological stations), remotely sensed data, and output from atmospheric prediction models. At high elevations, the observed discharge is very high in comparison with precipitation. Runoff coefficients exceed 100% in many of the highest watersheds. A glacier inventory performed with aerial photographs and ASTER images was combined with information from past studies, suggesting that glacier retreat could contribute between 5% and 10% of the discharge at 3000 m in the most glacierized catchment of the region. Snow extent was studied using MOD10A2 data. Results show that snow is present during 4 months at above 3000 m, suggesting that snow processes are crucial. The mean annual sublimation (˜80 mm a-1 at 4000 m) was estimated from the regional circulation model (WRF) and data from past studies. Finally, spatial distribution of precipitation was derived from available surface data and the global forecast system (GFS) atmospheric prediction model. Results suggest that annual precipitation is three to five times higher near the peak of the Andes than in the lowlands to the west. The GFS model suggests that daily precipitation rates in the mountains are similar to those in the coastal region, but precipitation events are more frequent and tend to last longer. Underestimation of summer precipitation may also explain part of the excess in discharge. Simple calculations show that consideration of GFS precipitation distributions, sublimation, and glacier melt leads to a better hydrological balance.

  13. Engineering masterpieces : from the Andes to Siberia, Canadian talent is in demand

    Energy Technology Data Exchange (ETDEWEB)

    Jaremko, G.

    2001-03-05

    Canadian oilfields are a prime breeding ground for talent, technology and industrial management. This paper described how Canadian talent was recognized in 2001 for three major projects which included a cold-ocean production platform in the Sea of Okhotsk in Siberia, a mountain pipeline project in South America, and an in-situ underground extraction technology in the oilsands of Alberta. The cold-ocean production platform project was recruited by Sakhalin Energy Investment Co., an international consortium originally led by Marathon Oil Co which is now led by Royal Dutch Shell. The oil production platform is stationed 16 kilometres offshore of Sakhalin Island in the Sea of Okhotsk. Sakhalin Energy bought and converted the Molikpaq, an innovative platform made in the 1980s for the Beaufort Sea by Gulf Canada Resources Ltd. The second project included Calgary's Hydroconsult EN3 Services Ltd. which was responsible for the construction of the 940-km GasAtacama 24-inch diameter pipeline between gas fields in northern Argentina and Chile through a 4,000 metre high mountain pass through the Andes. The formidable terrain meant that riverbeds were the only practical route. Pipeline was laid under the rivers, deep enough to escape the forces of wet-season runoff. During the construction, local irrigation systems were kept going with pumps. The final project involved an innovative technology known as steam assisted gravity drainage (SAGD) for enhanced recovery of the Alberta oilsands. Compared to strip-mining, SAGD has several advantages. The process separates the oil from the sand beneath the ground with paris of heat-injection and production wells. The system avoids the use of huge machinery, vast open pits and lake-size waste water ponds. The challenge is to ensure that environmental effects are monitored during the lifespan of any project. 6 figs.

  14. Facilitative interactions do not wane with warming at high elevations in the Andes.

    Science.gov (United States)

    Cavieres, Lohengrin A; Sierra-Almeida, Angela

    2012-10-01

    Positive interactions between species are known to play an important role in the structure and dynamics of alpine plant communities. The balance between negative and positive interactions is known to shift along spatial and temporal gradients, with positive effects prevailing over negative ones as the environmental stress increases. Thus, this balance is likely to be affected by climate change. We hypothesized that increases in temperature (a global warming scenario) should decrease the importance of positive interactions for the survival and growth of alpine plant species. To test this hypothesis, we selected individuals of the native grass species Hordeum comosum growing within the nurse cushion species Azorella madreporica at 3,600 m.a.s.l. in Los Andes (Chile), and performed nurse removal and seedling survival experiments under natural and warmer conditions. For warmer conditions, we used open-top chambers, which increased the temperature by 4 °C. After two growing seasons, we compared the effect of nurse removal on the survival, biomass, and photochemical efficiency of H. comosum individuals under warmer and natural conditions. Nurse removal significantly decreased the survival, biomass, and photochemical efficiency of H. comosum, demonstrating the facilitative effects of nurse cushions. Seedling survival was also enhanced by cushions, even under warmer conditions. However, warmer conditions only partially mitigated the negative effects of nurse removal, suggesting that facilitative effects of cushions do not wane under warmer conditions. Thus, facilitative interactions are vital to the performance and survival of alpine species, and these positive interactions will continue to be important in the warmer conditions of the future in high-alpine habitats. PMID:22481305

  15. Comparative phylogeography of co-distributed Phrygilus species (Aves, Thraupidae) from the Central Andes.

    Science.gov (United States)

    Álvarez-Varas, R; González-Acuña, D; Vianna, J A

    2015-09-01

    The Neotropical ecoregion has been an important place of avian diversification where dispersal and allopatric events coupled with periods of active orogeny and climate change (Late Pliocene-Pleistocene) have shaped the biogeography of the region. In the Neotropics, avian population structure has been sculpted not only by geographical barriers, but also by non-allopatric factors such as natural selection and local adaptation. We analyzed the genetic variation of six co-distributed Phrygilus species from the Central Andes, based on mitochondrial and nuclear markers in conjunction with morphological differentiation. We examined if Phrygilus species share patterns of population structure and historical demography, and reviewed the intraspecific taxonomy in part of their geographic range. Our results showed different phylogeographic patterns between species, even among those belonging to the same phylogenetic clade. P. alaudinus, P. atriceps, and P. unicolor showed genetic differentiation mediated by allopatric mechanisms in response to specific geographic barriers; P. gayi showed sympatric lineages in northern Chile, while P. plebejus and P. fruticeti showed a single genetic group. We found no relationship between geographic range size and genetic structure. Additionally, a signature of expansion was found in three species related to the expansion of paleolakes in the Altiplano region and the drying phase of the Atacama Desert. Morphological analysis showed congruence with molecular data and intraspecific taxonomy in most species. While we detected genetic and phenotypic patterns that could be related to natural selection and local adaptation, our results indicate that allopatric events acted as a major factor in the population differentiation of Phrygilus species. PMID:25987531

  16. Evolution of crustal thickening in the central Andes, Bolivia

    Science.gov (United States)

    Eichelberger, Nathan; McQuarrie, Nadine; Ryan, Jamie; Karimi, Bobak; Beck, Susan; Zandt, George

    2015-09-01

    Paleoelevation histories from the central Andes in Bolivia have suggested that the geodynamic evolution of the region has been punctuated by periods of large-scale lithospheric removal that drive rapid increases in elevation at the surface. Here, we evaluate viable times and locations of material loss using a map-view reconstruction of the Bolivian orocline displacement field to forward-model predicted crustal thicknesses. Two volumetric models are presented that test assumed pre-deformation crustal thicknesses of 35 km and 40 km. Both models predict that modern crustal thicknesses were achieved first in the northern Eastern Cordillera (EC) by 30-20 Ma but remained below modern in the southern EC until ≤10 Ma. The Altiplano is predicted to have achieved modern crustal thickness after 10 Ma but only with a pre-deformation thickness of 50 km, including 10 km of sediment. At the final stage, the models predict 8-25% regional excess crustal volume compared to modern thickness, largely concentrated in the northern EC. The excess predicted volume from 20 to 0 Ma can be accounted for by: 1) crustal flow to the WC and/or Peru, 2) localized removal of the lower crust, or 3) a combination of the two. Only models with initial crustal thicknesses >35 km predict excess volumes sufficient to account for potential crustal thickness deficits in Peru and allow for lower crustal loss. However, both initial thickness models predict that modern crustal thicknesses were achieved over the same time periods that paleoelevation histories indicate the development of modern elevations. Localized removal of lower crust is only necessary in the northern EC where crustal thickness exceeds modern by 20 Ma, prior to paleoelevation estimates of modern elevations by 15 Ma. In the Altiplano, crustal thicknesses match modern values at 10 Ma and can only exceed modern values by 5 Ma, post-dating when modern elevations were thought to have been established. Collectively, these models predict that

  17. Aridity changes in the temperate-Mediterranean transition of the Andes since ad 1346 reconstructed from tree-rings

    Energy Technology Data Exchange (ETDEWEB)

    Christie, Duncan A.; Quesne, Carlos le [Universidad Austral de Chile, Laboratorio de Dendrocronologia, Facultad de Ciencias Forestales y Recursos Naturales, Valdivia (Chile); Boninsegna, Jose A.; Morales, Mariano S.; Villalba, Ricardo [Instituto Argentino de Nivologia, Glaciologia y Ciencias Ambientales, IANIGLA, Departamento de Dendrocronologia e Historia Ambiental, Mendoza (Argentina); Cleaveland, Malcolm K.; Stahle, David W. [University of Arkansas Fayetteville, Tree-Ring Laboratory, Department of Geosciences, Fayetteville, AR (United States); Lara, Antonio [Universidad Austral de Chile, Laboratorio de Dendrocronologia, Facultad de Ciencias Forestales y Recursos Naturales, Valdivia (Chile); Universidad Austral de Chile, Forest Ecosystem Services under Climatic Fluctuations (Forecos), Valdivia (Chile); Mudelsee, Manfred [Climate Risk Analysis, Hanover (Germany); Alfred Wegener Institute for Polar and Marine Research, Bremerhaven (Germany)

    2011-04-15

    The Andes Cordillera acts as regional ''Water Towers'' for several countries and encompasses a wide range of ecosystems and climates. Several hydroclimatic changes have been described for portions of the Andes during recent years, including glacier retreat, negative precipitation trends, an elevation rise in the 0 isotherm, and changes in regional streamflow regimes. The Temperate-Mediterranean transition (TMT) zone of the Andes (35.5 -39.5 S) is particularly at risk to climate change because it is a biodiversity hotspot with heavy human population pressure on water resources. In this paper we utilize a new tree-ring network of Austrocedrus chilensis to reconstruct past variations in regional moisture in the TMT of the Andes by means of the Palmer Drought Severity Index (PDSI). The reconstruction covers the past 657 years and captures interannual to decadal scales of variability in late spring-early summer PDSI. These changes are related to the north-south oscillations in moisture conditions between the Mediterranean and Temperate climates of the Andes as a consequence of the latitudinal position of the storm tracks forced by large-scale circulation modes. Kernel estimation of occurrence rates reveals an unprecedented increment of severe and extreme drought events during the last century in the context of the previous six centuries. Moisture conditions in our study region are linked to tropical and high-latitude ocean-atmospheric forcing, with PDSI positively related to Nino-3.4 SST during spring and strongly negatively correlated with the Antarctic Oscillation (AAO) during summer. Geopotential anomaly maps at 500-hPa show that extreme dry years are tightly associated with negative height anomalies in the Ross-Amundsen Seas, in concordance with the strong negative relationship between PDSI and AAO. The twentieth century increase in extreme drought events in the TMT may not be related to ENSO but to the positive AAO trend during late-spring and

  18. Diversity of Quinoa in a Biogeographical Island: a Review of Constraints and Potential from Arid to Temperate Regions of Chile

    Directory of Open Access Journals (Sweden)

    Didier BAZILE

    2014-12-01

    Full Text Available Chile, isolated by a hyper-arid desert in the north, the Andes Range to the east and the Pacific and Antarctic waters (west and south, has a highly endemic flora. This hotspot of biodiversity is in danger not only due to increasing desertification, but also because human activities can diminish agrobiodiversity. Quinoa (Chenopodium quinoa Willd. is an Andean species producing highly nutritious grains, which almost disappeared from Chile during the Spanish colonization. Today less than 300 small-scale and highly isolated farmers still grow it as a rain-fed crop. This review describes the biogeographical-social context of quinoa in Chile, and its high genetic diversity as a product of a long domestication process, resulting in numerous local landraces whose conservation and use for breeding improved varieties is of paramount importance. We suggest the term “lighthouse crop” to emphasize its contribution to small scale ecological and bio diverse agriculture, particularly in stressful environments, to promote a healthier nutrition and more equitable markets in the world. Furthermore this crop and its exceptional nutritional properties were invoked by the United Nations Food and Agriculture Organization (FAO to promote its use worldwide, and to declare 2013 the International Year of Quinoa.

  19. Chemical and isotopic investigations of runoff in a mountainous watershed, Venezuelan Andes (Rio Bocono)

    International Nuclear Information System (INIS)

    The Rio Bocono watershed, located in the Western part of Venezuela on the South western side of Andes is considered by the 'Ministerio de1 Ambiente y de los Recursos Naturales Renovables' (MARN) as a priority zone for environmental management. The studies of relation between flow, dissolved elements and solid transport are essential to estimate soil degradation and sediment deposition which provokes loss of depth in the dam reservoir at the Southern margin of the basin. Because of the large surface which reach 1540 km2, the lack of equipment and the flash flood character of the river do not enable the flow mechanisms and transit times to be determined using usual hydrologic methods; therefore this problem has been approached by the way of chemical and isotopic investigation

  20. Radiation doses in neuroangiography for a clinical hospital in Chile; Dosis de radiacion en neuroangiografia para un hospital clinico de Chile

    Energy Technology Data Exchange (ETDEWEB)

    Vergara, F.; Valenzuela, E., E-mail: franciscovergara@hotmail.com [Pontificia Universidad Catolica de Chile, Santiago (Chile). Facultad de Medicina. Centro de Terapia Endovascular; Ubeda, C.A.; Nocetti, D., E-mail: carlos.ubeda.uta@gmail.com [Universidade de Tarapaca (Chile). Centro de Estudos en Ciencias Radiologicas (CECRad). Dept. de Tecnologic Medica. Facultad de Ciencias de la Salud (FACSAL)

    2013-11-01

    The objective of this study is to estimate the levels of radiation to the patient in neuroangiography procedures diagnostic and therapy in a Chile's Hospital, using a biplane angiographic system Siemens model ArtisZee. This research was conducted under the auspices of the International Atomic Energy Agency and the support of their radiation protection programs for patients.

  1. Glacier shrinkage and water resources in the Andes

    Science.gov (United States)

    Francou, Bernard; Coudrain, Anne

    For more than a century glaciers around the world have been melting as air temperatures rise due to a combination of natural processes and human activity. The disappearance of these glaciers can have wide-ranging effects, such as the creation of new natural hazards or changes in stream flow that could threaten water suppliesSome of the most dramatic melting has occurred in the Andes mountain range in South America. To highlight the climatic and glacial change in the Andes and to encourage the scientific community to strengthen the glacier observation network that stretches from Colombia to the Patagonian ice fields, the Instituto Nacional de Recursos Naturales (INRENA), Perú, and the Institute of Research and Development (IRD), France, recently organized the second Symposium on Mass Balance of Andean Glaciers in Huaráz,Perú.

  2. Modeling the Glacial Buzzsaw in the Patagonian Andes

    Science.gov (United States)

    Brandon, M. T.; Tomkin, J. H.

    2006-12-01

    Modeling the Glacial Buzzsaw in the Patagonian Andes The concept of a "glacial buzzsaw" was spawned by Steve Porter's observation in 1977 and 1988 that the "equilibrium line altitude" (ELA) for alpine glaciation in the Andes parallels the summit elevations of the range. The modern ELA in the Patagonian Andes drops from about 4.5 km at 30 S to about 1 km at 50 S, due to colder temperatures at higher latitudes. The summit elevations decrease steadily by a similar amount over this 2200 km distance. The landscape of the western side of the Patagonian Andes clearly shows that it has long been dominated by glacial erosion. Locally preserved tills indicate that alpine glaciation was active at 7 to 4.6 Ma, if not earlier. The idea of a glacial buzzsaw is that erosion by alpine glaciers is aggressive enough to limit the height of a mountain range. Fission-track cooling ages indicate modest long-term erosion rates (~0.5 to 1 km/Ma) for the Patagonian Andes, which precludes the possibility that the range was trimmed down to size by Quaternary- age glaciations. Furthermore, the range shows clear evidence of growth by continental subduction and tectonic accretion along its eastern margin. Evidence for recent tectonic shortening is based on the observation that the range has an approximately constant taper, as expected for a critical wedge. The width of the range decreases southward in parallel with the decreasing summit elevations. We have developed a general analytical model for coupled wedge growth and glacial erosion that accounts for much of the tectonic evolution of the Patagonian Andes. The model is based on an actively accreting wedge that maintains a constant taper geometry. The size of the wedge is controlled by competition between accretion and glacial erosion. Recent work by one of us (JHT) and Gerard Roe shows that the erosional yield caused by alpine glaciation is approximately proportional to the local elevation difference between the summit of the range and the

  3. Rapid millennial-scale vegetation changes in the tropical Andes

    Directory of Open Access Journals (Sweden)

    D. H. Urrego

    2015-05-01

    Full Text Available We compare eight pollen records reflecting climatic and environmental change from the tropical Andes. Our analysis focuses on the last 50 ka, with particular emphasis on the Pleistocene to Holocene transition. We explore ecological grouping and downcore ordination results as two approaches for extracting environmental variability from pollen records. We also use the records of aquatic and shoreline vegetation as markers for lake level fluctuations, and precipitation change. Our analysis focuses on the signature of millennial-scale variability in the tropical Andes, in particular, Heinrich stadials and Greenland interstadials. We identify rapid responses of the tropical vegetation to this climate variability, and relate differences between sites to moisture sources and site sensitivity.

  4. Zeolitización de rocas andesíticas

    Directory of Open Access Journals (Sweden)

    Plana, F.

    1989-12-01

    Full Text Available The study of some andesites from King George Island (South Shetland Islands, Anctartica has pointed out the existence of a hydrothermal alteration process going rise to a zeolitic secondary minerals of low-temperature assemblages. Two paragenesis have been identified (Smectite-Bytownite-Mordenite, Smectite-Albite-Laumontite which reflecting different conditions durign the hydrothermal alteration of these andesitic rocksEl estudio de rocas andesíticas de la Isla King George (Archipiélago de las Shetland del Sur, Antártida pone de manifiesto la existencia de procesos de alteración hidrotermal con la formación de minerales zeolíticos secundarios pertenecientes a asociaciones de baja temperatura. Se han identificado dos paragénesis (Esmectitas-Bytownita-Mordenita, Esmectitas-AlbitaLaumontita que reflejan distintas condiciones durante la alteración hidrotermal de dichas rocas andesíticas.

  5. Cenozoic crustal shortening and thickening contributions to Andean orogenesis: Preliminary results from structural mapping in the southern Peruvian Andes

    Science.gov (United States)

    Perez, N.; Horton, B. K.

    2012-12-01

    Estimates of Cenozoic crustal shortening and thickening from the southern Peruvian Andes are necessary to address ongoing debates regarding growth of the Andes and Altiplano plateau. However, limited regional studies in southern Peru prevent accurate assessments of the structural contributions to high topography. This study provides new structural mapping along a >200 km transect spanning the northernmost Altiplano to Subandes at 13-15.5°S and fills the gap between existing central Peruvian and northern Bolivian studies. New stratigraphic data, fault relationships and fold orientations are used to create an updated geologic map and provide insights into the style, timing and magnitude of crustal deformation. Preliminary cross sections accompanying these map transects illustrate deformation style and provide first-order estimates of shortening. Further cross section analyses will be balanced and provide estimates of total crustal shortening and associated thickening in southern Peru. The study transect is subdivided into belts according to the age of exposed rocks and style of deformation. From west to east these belts include: Cretaceous strata dominated by tight folds, closely spaced faults and multiple detachments; Permo-Triassic strata dominated by thicker thrust sheets and fault-fold orientations departing from typical Andean trends; and Paleozoic rocks characterized by thick thrust sheets and deformation focused near major faults. The Cretaceous belt is composed of marine limestones and upward coarsening, siltstone to coarse sandstone progradational sequences. Disharmonic and detachment folds in the Cretaceous section demonstrate the importance of interbedded gypsum and mudstone layers. Fault relationships suggest local shortening during the Early Cretaceous. The Permo-Triassic belt is composed of thick Permian carbonates (Copacabana Formation) and interbedded sandstones, conglomerates and volcanics of the Mitu Formation. This study defines the orientation of

  6. Excess Returns and Systemic Risk for Chile and Mexico Excess Returns and Systemic Risk for Chile and Mexico

    Directory of Open Access Journals (Sweden)

    Paul D. McNelis

    2000-03-01

    Full Text Available This paper is concerned with excess returns in the equity markets and the evolution of systemic risk in Chile and Mexico during the years 1989-1998, a period of financial openness, policy reform and crisis. A time varying generalised autoregressive conditional heteroscedastic in mean framework is used to estimate progressively more complex models of risk. They include the univariate own volatily model, the bivariate market pricing model, and the trivariate intertemporal asset pricing model. The results show no evidence of a significant reduction in systemic risk rather excess returns have remained volatile for both countries. For Chile, excess returns are significantly related to own lagged levels, while for Mexico excess are significantly related to own lagged variances. The influence of global factors are relatively minimal compared to potential home factors. This paper is concerned with excess returns in the equity markets and the evolution of systemic risk in Chile and Mexico during the years 1989-1998, a period of financial openness, policy reform and crisis. A time varying generalised autoregressive conditional heteroscedastic in mean framework is used to estimate progressively more complex models of risk. They include the univariate own volatily model, the bivariate market pricing model, and the trivariate intertemporal asset pricing model. The results show no evidence of a significant reduction in systemic risk rather excess returns have remained volatile for both countries. For Chile, excess returns are significantly related to own lagged levels, while for Mexico excess are significantly related to own lagged variances. The influence of global factors are relatively minimal compared to potential home factors.

  7. Spatio-temporal variability of snow water equivalent in the extra-tropical Andes Cordillera from distributed energy balance modeling and remotely sensed snow cover

    OpenAIRE

    E. Cornwell; Molotch, N. P.; McPhee, J

    2016-01-01

    Seasonal snow cover is the primary water source for human use and ecosystems along the extratropical Andes Cordillera. Despite its importance, relatively little research has been devoted to understanding the properties, distribution and variability of this natural resource. This research provides high-resolution (500 m), daily distributed estimates of end-of-winter and spring snow water equivalent over a 152 000 km2 domain that includes the mountainous reaches of central Chi...

  8. Spatio-temporal variability of snow water equivalent in the extra-tropical Andes cordillera from a distributed energy balance modeling and remotely sensed snow cover

    OpenAIRE

    E. Cornwell; Molotch, N. P.; McPhee, J

    2015-01-01

    Seasonal snow cover is the primary water resource precursor for human use and environmental sustain along the extratropical Andes Cordillera. Despite its importance, relatively little research has been devoted to understanding the properties, distribution and variability of this natural resource. This research provides high-resolution distributed estimates of end-of-winter and spring snow water equivalent over a 152 000 km2 domain that includes the mountainous reaches of ...

  9. Sistema de salud de Chile The health system of Chile

    OpenAIRE

    Víctor Becerril-Montekio; Juan de Dios Reyes; Annick Manuel

    2011-01-01

    En este trabajo se describe el sistema de salud de Chile, incluyendo su estructura, financiamiento, beneficiarios y recursos físicos, materiales y humanos de los que dispone. Este sistema está compuesto por dos sectores, público y privado. El sector público está formado por todos los organismos que constituyen el Sistema Nacional de Servicios de Salud y cubre aproximadamente a 70% de la población, incluyendo a los pobres del campo y las ciudades, la clase media baja y los jubilados, así como ...

  10. A Younger Dryas glacierization in the Venezuelan Andes

    Science.gov (United States)

    Stansell, N. D.; Abbott, M. B.; Polissar, P. J.; Bezada, M.

    2007-12-01

    The Younger Dryas (YD) was an abrupt climate change event that has been well recorded in marine archives, but is still uncertain in terrestrial records from the tropics. For instance, the YD is recorded in the Cariaco Basin as an event of increased upwelling intensity and decreased terrigenous input; however continental records of a coincident climate change event across the region are inconclusive. Moreover, pollen data from the Colombian Andes suggest that there was a local cold stadial that coincides with the YD, but paleoenvironmental records from the Venezuelan Andes during the same time interval are not clear. Here we present a high-resolution late- glacial sequence from the Pico Espejo region of Venezuela. Our record is based on radiocarbon dated lake sediments that were analyzed using magnetic susceptibility, scanning X-ray fluorescence and loss-on-ignition methods. The sequence contains a period of increased glacial-sedimentary flux between ca. 13,000 and 12,000 cal yr BP, which coincides with the timing of the YD. Glacio-lacustrine sediments also increased between ca. 11,000 to 10,000 cal yr BP. Combined, these data suggest the northern tropical Andes experienced cooling events during the YD, and from ca. 11,000 to 10,000 cal yr BP.

  11. Chile : Household Risk Management and Social Protection

    OpenAIRE

    World Bank, (WB)

    2004-01-01

    This report is part of the World Bank's advisory and analytical assistance to the Government of Chile. The report examines whether Chile has a social protection "system" - broadly defined to include policy interventions, public institutions, and the regulation of private institutions that lower the welfare costs of adverse shocks to income from job loss and extended unemployment, health ep...

  12. Earthquake engineering research program in Chile

    Science.gov (United States)

    Saragoni, G. R.

    1982-01-01

    Earthquake engineering research in Chile has been carried out for more than 30 years. Systematic research is done at the university of Chile in Santiago. Other universities such as the Catholic University, university of Concepcion, and the Federico Santa Maria Technical University have begun to teach and conduct research in earthquake engineering in recent years. 

  13. Streamflow responses in Chile to megathrust earthquakes in the 20th and 21st centuries

    Science.gov (United States)

    Mohr, Christian; Manga, Michael; Wang, Chi-yuen; Korup, Oliver

    2016-04-01

    Both coseismic static stress and dynamic stresses associated with seismic waves may cause responses in hydrological systems. Such responses include changes in the water level, hydrochemistry and streamflow discharge. Earthquake effects on hydrological systems provide a means to study the interaction between stress changes and regional hydrology, which is otherwise rarely possible. Chile is a country of frequent and large earthquakes and thus provides abundant opportunities to study such interactions and processes. We analyze streamflow responses in Chile to several megathrust earthquakes, including the 1943 Mw 8.1 Coquimbo, 1950 Mw 8.2 Antofagasta, 1960 Mw 9.5 Valdivia, 1985 Mw 8.0 Valparaiso, 1995 Mw 8.0 Antofagasta, 2010 Mw 8.8 Maule, and the 2014 Mw 8.2 Iquique earthquakes. We use data from 716 stream gauges distributed from the Altiplano in the North to Tierra del Fuego in the South. This network covers the Andes mountain ranges, the central valley, the Coastal Mountain ranges and (mainly in the more southern parts) the Coastal flats. We combine empirical magnitude-distance relationships, machine learning tools, and process-based modeling to characterize responses. We first assess the streamflow anomalies and relate these to topographical, hydro-climatic, geological and earthquake-related (volumetric and dynamic strain) factors using various classifiers. We then apply 1D-groundwater flow modeling to selected catchments in order to test competing hypotheses for the origin of streamflow changes. We show that the co-seismic responses of streamflow mostly involved increasing discharges. We conclude that enhanced vertical permeability can explain most streamflow responses at the regional scale. The total excess water released by a single earthquake, i.e. the Maule earthquake, yielded up to 1 km3. Against the background of megathrust earthquakes frequently hitting Chile, the amount of water released by earthquakes is substantial, particularly for the arid northern

  14. 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

  15. Origin of the regional stress field along the Liquine-Ofqui Fault Zone (LOFZ), Southern Chilean Andes by means of FE Simulation

    Institute of Scientific and Technical Information of China (English)

    Md. Rafiqul Islam

    2009-01-01

    The Liquine-Ofqui Fault Zone (LOFZ) of southern Chilean Andes is one of the largest active strike-slip fault zones. There is an ongoing debate regarding the origin of the stress field along the LOFZ due to its complex geometry. This paper represents a study of the origins of the LOFZ regional stress field. Stress fields are calculated by finite element (FE) analysis. The two possible stress origins, i.e., oblique plate convergence and ridge collision/indenter tectonics of Chile ridge against Peru-Chile trench, have been emphasized in the present study. Three types of boundary conditions for the three particular models have been applied to calculate stress fields. Models are assumed to be elastic and plane stress condition. Modeling results are presented in terms of four parameters, i. e., orientation of maximum horizontal stress (σHmax), displacement vector, strain distribution, and maximum shear stress (τmax) contour line within the model. The results of the first model with oblique plate convergence show inconsistency between the geometric shape of the LOFZ and the distribution of the four parameters. Although more realistic results are obtained from the second model with normal ridge collision, there are few coincident in the LOFZ geometry and regional stress field. The third model with normal and oblique ridge collision is reasonable in understanding the origin of stress field and geometrical condition in the lithosphere of the LOFZ.

  16. Sistema de salud de Chile

    OpenAIRE

    Víctor Becerril-Montekio; Juan de Dios Reyes; Annick Manuel

    2011-01-01

    En este trabajo se describe el sistema de salud de Chile, incluyendo su estructura, financiamiento, beneficiarios y recursos físicos, materiales y humanos de los que dispone. Este sistema está compuesto por dos sectores, público y privado. El sector público está formado por todos los organismos que constituyen el Sistema Nacional de Servicios de Salud y cubre aproximadamente a 70% de la población, incluyendo a los pobres del campo y las ciudades, la clase media baja y los jubilados, así como ...

  17. What controls millennial-scale denudation rates across the Central Andes?

    Science.gov (United States)

    Zeilinger, Gerold; Korup, Oliver; Schlunegger, Fritz; Kober, Florian

    2015-04-01

    Sustainable planning of erosion control measures in the Central Andes requires robust knowledge about natural denudation rates. We explore a large dataset combining new and published 10Be (and 26Al) catchment-wide denudation rates from a swath at 17 to 19° S spanning the Western Cordillera that rises from sea level to 5500 m elevation; the Altiplano at ~4000 m; the Eastern Cordillera with elevations up to 6500 m; the Interandean Zone; the Subandean Zone; and the Chaco Plain at 300 m. The selected catchments span a large spread regarding morphometric and climate properties where mean slope angles range from 1 to 31°, and mean precipitation from 100 to 3900 mm/a. The denudation rates (0.0036 to 1.93 mm/a) are averaged over millennia, and reveal two to three magnitudes difference across the Central Andes. The regional distribution of denudation rates clearly demonstrates a more complex interaction of geomorphological, geological and meteorological parameters with the dominant geomorphological processes. In order to elucidate the key controls on denudation, we use multivariate statistics such as principal component analysis in order to remove potentially redundant predictors of denudation in the studied catchments. These predictors include catchment elevation, topographic relief, hillslope inclination, mean precipitation, tree cover, specific stream power, channel steepness indices, sinuosity, drainage density and hypsometric index that we derived from the SRTM 90 m Digital Elevation Database, the Tropical Rainfall Measuring Mission (TRMM) data, and the Terra MODIS Vegetation Continuous Fields dataset. Additionally, the rock strength index (PLI) was estimated based on geological units. Preliminary results allow distinguishing five different longitudinal domains of denudation on the basis of climatic regime, hillslope steepness, and the degree of accumulated crustal deformation. We find that the pattern of 10Be catchment-wide denudation rates in the Central Andes

  18. Geochronologic and paleontologic evidence for a Pacific-Atlantic connection during the late Oligocene-early Miocene in the Patagonian Andes (43-44°S)

    Science.gov (United States)

    Encinas, Alfonso; Pérez, Felipe; Nielsen, Sven N.; Finger, Kenneth L.; Valencia, Victor; Duhart, Paul

    2014-11-01

    Cenozoic marine strata occur in the western, eastern, and central parts of the North Patagonian Andes between ˜43°S and 44°S. Correlation of these deposits is difficult because they occur in small and discontinuous outcrops and their ages are uncertain. In order to better understand the age and sedimentary environment of these strata, we combined U-Pb (LA-MC-ICPMS) geochronology on detrital zircons with sedimentologic and paleontologic (foraminifers and molluscs) studies. Sedimentologic analyses suggest that the Puduhuapi Formation on the western flank of the Andean Cordillera was deposited in a deep-marine setting, the Vargas Formation in the central part of the Andes was deposited at outer-neritic or bathyal depths, and the La Cascada Formation on the eastern flank of the range was deposited in a shallow-marine environment. Geochronologic and paleontologic results indicate that the three marine units were deposited during the late Oligocene-early Miocene interval, although it is not clear whether this occurred during one or more marine incursions in the area. The alluvial(?) conglomeratic deposits of the La Junta Formation, exposed in the proximity of the Vargas Formation outcrops, have a maximum depositional age of ˜26 Ma and could have been deposited during the initial stage of subsidence that affected this region prior to the marine transgression over this area. The occurrence of both Pacific and Atlantic molluscan taxa in the La Cascada and Vargas formations suggests that a marine strait connected both oceans during the accumulation of these units. The new data on the age of the Puduhuapi, Vargas, and La Cascada formations indicate that these units may correlate with lower Miocene marine deposits in the forearc of central and southern Chile (Navidad Formation and equivalent units) and on the eastern flank of the Patagonian Andes (Río Foyel Formation and equivalent units). A late Oligocene-early Miocene age for these marine deposits is a reliable maximum

  19. Caracterización y procedencia de obsidianas de sitios arqueológicos del Centro Oeste de Argentina y Centro de Chile con metodología no destructiva por fluorescencia de Rayos X (XRF Non-destructive x-ray fluorescence (XRF characterization and sourcing of obsidian from archaeological sites in Central West Argentina and Central Chile

    Directory of Open Access Journals (Sweden)

    Víctor Durán

    2012-11-01

    Full Text Available Se presentan los resultados de 101 análisis químicos por fluorescencia de Rayos X efectuados sobre artefactos de obsidiana provenientes de sitios arqueológicos del Centro Oeste Argentino y Chile Central. También se hace una caracterización química de seis fuentes y subfuentes de obsidiana ubicadas en ambientes cordilleranos y extracordilleranos del sur de Mendoza, Neuquén y Chile Central. Con esa información se discuten propuestas referidas a la movilidad y sistemas de intercambio de las sociedades humanas que ocuparon las dos vertientes de la cordillera de Los Andes durante el Holoceno medio y tardío. Los resultados obtenidos confirman que el método no destructivo por XRF es una herramienta válida para determinar el origen y dispersión de las obsidianas arqueológicas.The results of chemical analysis by X-ray Fluorescence (XRF performed on 101 obsidian artifacts from archaeological sites of Central western Argentina and Central Chile are presented. A chemical characterization of six obsidian sources and subsources located in both Andean and extra-Andean environments of Southern Mendoza, Northern Neuquén and Central Chile, is also performed. Based on this information, different proposals related to mobility patterns and exchange systems of human societies that occupied the two slopes of the Andes during the middle and late Holocene are discussed. The results confirm that non-destructive X-ray Fluorescence is a valid tool to determine the origin and dispersal of archaeological obsidian artifacts.

  20. Climate change and energy policy in Chile: Up in smoke?

    International Nuclear Information System (INIS)

    This paper provides an ex-post assessment of the climate and energy policy developments in Chile emerging from a neoliberal economic model, during the period 1971–2007. First, correlation and regression analyses were performed to analyse historical CO2 emissions as a product of demographic, economic and energy-wide drivers. Then I estimate indicators related to CO2 emissions, energy use and economic activity. In the light of empirical results, I identify policy instruments and structural issues. Finally, I present a comparative analysis of Chile and other Latin American countries. Statistical tests show that variability of CO2 emissions is explained mostly by GDP per capita (‘affluence’) than any other tested variable. Indicators show that the diversification and decarbonisation of the energy mix has been a major policy challenge. With two notable exceptions (hydro and natural gas), the CO2 intensity of the energy supply mix suggests no effective policies, while energy security crises triggered negative carbon effects and increased prices. No clear policies to promote energy efficiency can be identified until 2005. Explicit policy instruments to promote renewable energy are only recognised after 2004. The results strongly suggest that Chile lacked of policies to effectively decarbonise its energy–economy system. - Highlight: ► The first paper that quantitatively assesses key drivers of CO2 emissions in Chile. ► It examines energy and climate policy development during the period 1971–2007. ► GDP per capita (‘affluence’) is the main determinant of CO2 emissions. ► Diversification and decarbonisation of energy mix has been a major policy challenge. ► Policy approach under analysed period not suited for a low-carbon economy.

  1. EL RACISMO AMBIENTAL EN CHILE

    Directory of Open Access Journals (Sweden)

    MATÍAS MEZA-LOPEHANDÍA

    2011-06-01

    Full Text Available El problema de la desigualdad en Chile ha sido abordado desde diferentes puntos de vista como la cuestión de la distribución de la riqueza o el acceso a los derechos sociales. Es este trabajo se observa el mismo problema pero desde la perspectiva recientemente esbozada por los movimientos sociales: la del racismo ambiental o la desigual distribución de los deshechos del desarrollo y el consumo. De esta manera se revisan sucintamente los principales conflictos que han surgido en el último tiempo a lo largo del país entre empresas públicas y privadas y comunidades locales y originarias. Así mismo se examinan las formas de organización que estas últimas han asumido y el estado actual de articulación entre ellas. De la revisión de la situación se concluye que estamos ante el surgimiento de un actor de nuevo tipo, que surge de las contradicciones del Chile neoliberal y que se diferencia del movimiento ecologista por vincular sus reivindicaciones a la defensa del territorio y al derecho a la autodeterminación de los pueblos.

  2. Miedo y represionpolitica en Chile

    Directory of Open Access Journals (Sweden)

    Amado M. Padilla

    1987-01-01

    Full Text Available This paper describes a human rights fact-finding mission to Chile concerned with the use of psychological techniques employed in offlcia- Uy sactioned torture and repressíon, Meetings and interviews were conducted with representatives of many organízatíons working with víctima of governrnental repression including the Chílean Psychological Assocíation. Fear and repression wene found to be widespread among all socioeconomic segments of the population. Physical and psychological abuses directed at individuals are díscussed, Psychological techníques used in the control of social groups such as intimidation, control of information, and community destabilization are also described. It is concluded that violations of human rigths are a reality in Chile. Ways to support the work of Chilean psychologists must be sought sínce the damaging eonsequences of officially sanctioned repressíon are wid.espread, and resources are minimal.

  3. President of Chile at CERN

    CERN Multimedia

    2007-01-01

    The President of Chile, Michelle Bachelet, in the ATLAS cavern with, from left to right, Peter Jenni, ATLAS Spokesman, Vivian Heyl, CONICYT President, and Robert Aymar, CERN Director-General. Robert Aymar, CERN Director-General, and Vivian Heyl, CONICYT President, signing a cooperation agreement between CERN and Chile’s Comisión Nacional de Investigación Científica y Tecnológica (CONICYT).The President of Chile, Michelle Bachelet, paid a visit to CERN during her three-day tour of Switzerland. The charismatic Michelle Bachelet and her large delegation were greeted by the CERN Director-General and then taken to see the ATLAS experiment and the LHC. She also took time to meet the Chilean community working at CERN, comprising several physicists in the Theory Group and the ATLAS experiment. The meeting was followed by the signing of a cooperation agreement between CERN and Chile’s Comisión Nacional de Investigación Científi...

  4. Proliferation of hydroelectric dams in the Andean Amazon and implications for Andes-Amazon connectivity.

    Directory of Open Access Journals (Sweden)

    Matt Finer

    Full Text Available Due to rising energy demands and abundant untapped potential, hydropower projects are rapidly increasing in the Neotropics. This is especially true in the wet and rugged Andean Amazon, where regional governments are prioritizing new hydroelectric dams as the centerpiece of long-term energy plans. However, the current planning for hydropower lacks adequate regional and basin-scale assessment of potential ecological impacts. This lack of strategic planning is particularly problematic given the intimate link between the Andes and Amazonian flood plain, together one of the most species rich zones on Earth. We examined the potential ecological impacts, in terms of river connectivity and forest loss, of the planned proliferation of hydroelectric dams across all Andean tributaries of the Amazon River. Considering data on the full portfolios of existing and planned dams, along with data on roads and transmission line systems, we developed a new conceptual framework to estimate the relative impacts of all planned dams. There are plans for 151 new dams greater than 2 MW over the next 20 years, more than a 300% increase. These dams would include five of the six major Andean tributaries of the Amazon. Our ecological impact analysis classified 47% of the potential new dams as high impact and just 19% as low impact. Sixty percent of the dams would cause the first major break in connectivity between protected Andean headwaters and the lowland Amazon. More than 80% would drive deforestation due to new roads, transmission lines, or inundation. We conclude with a discussion of three major policy implications of these findings. 1 There is a critical need for further strategic regional and basin scale evaluation of dams. 2 There is an urgent need for a strategic plan to maintain Andes-Amazon connectivity. 3 Reconsideration of hydropower as a low-impact energy source in the Neotropics.

  5. Proliferation of Hydroelectric Dams in the Andean Amazon and Implications for Andes-Amazon Connectivity

    Science.gov (United States)

    Finer, Matt; Jenkins, Clinton N.

    2012-01-01

    Due to rising energy demands and abundant untapped potential, hydropower projects are rapidly increasing in the Neotropics. This is especially true in the wet and rugged Andean Amazon, where regional governments are prioritizing new hydroelectric dams as the centerpiece of long-term energy plans. However, the current planning for hydropower lacks adequate regional and basin-scale assessment of potential ecological impacts. This lack of strategic planning is particularly problematic given the intimate link between the Andes and Amazonian flood plain, together one of the most species rich zones on Earth. We examined the potential ecological impacts, in terms of river connectivity and forest loss, of the planned proliferation of hydroelectric dams across all Andean tributaries of the Amazon River. Considering data on the full portfolios of existing and planned dams, along with data on roads and transmission line systems, we developed a new conceptual framework to estimate the relative impacts of all planned dams. There are plans for 151 new dams greater than 2 MW over the next 20 years, more than a 300% increase. These dams would include five of the six major Andean tributaries of the Amazon. Our ecological impact analysis classified 47% of the potential new dams as high impact and just 19% as low impact. Sixty percent of the dams would cause the first major break in connectivity between protected Andean headwaters and the lowland Amazon. More than 80% would drive deforestation due to new roads, transmission lines, or inundation. We conclude with a discussion of three major policy implications of these findings. 1) There is a critical need for further strategic regional and basin scale evaluation of dams. 2) There is an urgent need for a strategic plan to maintain Andes-Amazon connectivity. 3) Reconsideration of hydropower as a low-impact energy source in the Neotropics. PMID:22529979

  6. Vegetation and climatic changes in the Merida Andes during the last 13.000 years

    International Nuclear Information System (INIS)

    A comparison of the paleoecological results from the Merida Andes, in Venezuela, including different elevations and different mountain ranges is presented. The purpose of this paper is to organize and compare the data from seven stratigraphic sections from Merida Andes in order to identify changes in vegetation and climate in the last 13,000 years. (author)

  7. TRMM- and GPM-based precipitation analysis and modelling in the Tropical Andes

    Science.gov (United States)

    Manz, Bastian; Buytaert, Wouter; Zulkafli, Zed; Onof, Christian

    2016-04-01

    Despite wide-spread applications of satellite-based precipitation products (SPPs) throughout the TRMM-era, the scarcity of ground-based in-situ data (high density gauge networks, rainfall radar) in many hydro-meteorologically important regions, such as tropical mountain environments, has limited our ability to evaluate both SPPs and individual satellite-based sensors as well as accurately model or merge rainfall at high spatial resolutions, particularly with respect to extremes. This has restricted both the understanding of sensor behaviour and performance controls in such regions as well as the accuracy of precipitation estimates and respective hydrological applications ranging from water resources management to early warning systems. Here we report on our recent research into precipitation analysis and modelling using various TRMM and GPM products (2A25, 3B42 and IMERG) in the tropical Andes. In an initial study, 78 high-frequency (10-min) recording gauges in Colombia and Ecuador are used to generate a ground-based validation dataset for evaluation of instantaneous TRMM Precipitation Radar (TPR) overpasses from the 2A25 product. Detection ability, precipitation time-series, empirical distributions and statistical moments are evaluated with respect to regional climatological differences, seasonal behaviour, rainfall types and detection thresholds. Results confirmed previous findings from extra-tropical regions of over-estimation of low rainfall intensities and under-estimation of the highest 10% of rainfall intensities by the TPR. However, in spite of evident regionalised performance differences as a function of local climatological regimes, the TPR provides an accurate estimate of climatological annual and seasonal rainfall means. On this basis, high-resolution (5 km) climatological maps are derived for the entire tropical Andes. The second objective of this work is to improve the local precipitation estimation accuracy and representation of spatial patterns of

  8. Patrimonio geológico del proyecto geoparque Cajón del Maipo (Región Metropolitana - Chile)

    OpenAIRE

    Wilson, José Miguel Benado

    2013-01-01

    Dissertação de mestrado em Património Geológico e Geoconservação La Comuna de San José de Maipo, también conocida como Cajón del Maipo, se ubica en la Cordillera de Los Andes, 50 km al este de la ciudad de Santiago (capital de Chile). Posee una superficie de ~5.000 km2 y una población de aproximadamente 13.000 habitantes. Es una Comuna considera semi-rural, fuertemente asociada a la práctica del ecoturismo y un área que fue declarada Zona de Interés Turístico Nacional. Esta cla...

  9. Socioeconomic School Segregation in a Market-Oriented Educational System. The Case of Chile

    Science.gov (United States)

    Valenzuela, Juan Pablo; Bellei, Cristian; de los Ríos, Danae

    2014-01-01

    This paper presents an empirical analysis of the socioeconomic status (SES) school segregation in Chile, whose educational system is regarded as an extreme case of a market-oriented education. The study estimated the magnitude and evolution of the SES segregation of schools at both national and local levels, and it studied the relationship between…

  10. The Iconography of Painted Ceramics from the Northern Andes Title: La iconografía de la cerámica pintada del norte de los Andes

    OpenAIRE

    Felipe Cárdenas-Arroyo

    1998-01-01

    Felipe Cárdenas-Arroyo, arqueólogo colombiano de la Universidad de Los Andes en Bogotá, erudito de CASVA, especialista en momificación pre-hispánica de huesos humanos.Abstract: Felipe Cárdenas-Arroyo, Colombian archaeologist from the University of Los Andes in Bogotá, CASVA scholar, specialist in pre-Hispanic mummification and human bone.

  11. Chile: los mapuches y el Bicentenario Chile: Mapuches e do Bicentenario Chile: Mapuche and the Bicentennial

    Directory of Open Access Journals (Sweden)

    José Bengoa

    2011-12-01

    Full Text Available El Bicentenario de la República de Chile se conmemoró en el mes de septiembre del año 2010. Además de marcar un importante hito histórico, coincidió con un cambio político en el Gobierno del país, el que pasó de la Concertación de Partidos por la Democracia a la Alianza de partidos formada por la derecha chilena. Se cumplieron por tanto 20 años desde que en el año 1990 cambiara el Gobierno militar presidido por el general Pinochet. Ese largo tiempo, dos décadas, coincide con un período de políticas que el Estado ha implementado hacia los Pueblos Indígenas. El Proyecto “Conmemoraciones y Memorias Subalternas” ha realizado durante el año 2010 un conjunto de investigaciones de terreno y documentales tendientes a comprender del modo más objetivo y científico lo ocurrido en el período y por tanto la situación actual de las sociedades mapuches en sus complejas relaciones con la chilena.O Bicentenario da República do Chile comemorou-se no mês de Setembro do ano 2010. Junto com transformar-se num marco histórico, coincidiu com uma mudança política no Governo do país, que passou da Concertação de Partidos pela Democracia (centro-esquerda à Aliança de partidos formada pela direita chilena. Cumpriram-se por tanto 20 anos desde que em 1990 mudasse o Governo militar presidido pelo general Pinochet. Esse longo tempo, duas décadas, coincide com um período de políticas que o Estado implementou para com os Povos Indígenas. O Projeto “Comemorações e Memórias Subalternas” realizou durante o ano 2010 um conjunto de pesquisas de campo e documentais tendentes a compreender do modo mais objetivo e científico o ocorrido no período e, por tanto, a situação atual das sociedades mapuches em suas complexas relações com a chilena.The conmeration of the 200 years of the Independence of Chile was in September 2010. This year was also the political change from the Concertación de Partidos por la Democracia to the right

  12. Increased water use efficiency but contrasting tree growth patterns in Fitzroya cupressoides forests of southern Chile during recent decades

    Science.gov (United States)

    Urrutia-Jalabert, Rocío.; Malhi, Yadvinder; Barichivich, Jonathan; Lara, Antonio; Delgado-Huertas, Antonio; Rodríguez, Carmen Gloria; Cuq, Emilio

    2015-12-01

    Little is known about how old-growth and massive forests are responding to environmental change. We investigated tree-ring growth and carbon isotopes of the long-lived and high biomass Fitzroya cupressoides in two stands growing in contrasting environmental conditions in the Coastal Range (~300 years old) and Andean Cordilleras (>1500 years old) of southern Chile. The interannual variability in δ13C was assessed for the period 1800-2010, and changes in discrimination and intrinsic water use efficiency (iWUE) were evaluated in relation to changes in climate and tree-ring growth during the last century. 13C discrimination has significantly decreased, and iWUE has increased since the 1900s in both sites. However, these trends in isotopic composition have been accompanied by different growth patterns: decreasing growth rates in the Coastal Range since the 1970s and increasing growth rates in the Andes since the 1900s. Trees growing in the Coastal Range have become more efficient in their use of water, probably due to reduced stomatal conductance caused by increases in CO2 and warming. Trees growing in the Andes have also become more water use efficient, but this has been likely due to increased photosynthetic rates. Fitzroya forests, including particularly old-growth stands, are responding to recent environmental changes, and their response has been site dependent. The growth of forests under a more Mediterranean climate influence and restrictive soil conditions in the Coastal Range has been more negatively affected by current warming and drying; while the growth of old stands in the wet Andes has been positively affected by changes in climate (decreasing cloudiness) and increasing CO2. Permanent monitoring of these endangered forests under ongoing environmental changes is needed in order to reassure the long-term preservation of this millennial-aged species.

  13. Fluvio-lacustrine sedimentation and volcanism in a Late Carboniferous tensional intra-arc basin, northern Chile

    Science.gov (United States)

    Breitkreuz, Christoph

    1991-11-01

    Extensive outcrops of Late Carboniferous to Triassic volcanoplutonic magnetic-arc complexes occur in the Andes of northern Chile. In the Salar de Atacama area, terrestrial volcanosedimentary successions include a 200-600 m thick fluvio-lacustrine sequence ("Miembro Medio"). The terrestrial basin which accommodated this sequence formed during the latest Carboniferous on top of the deposits of the pre-existing Carboniferous composite volcanoes. The lower part of the Miembro Medio consists of green limnic and multicoloured alluvial fan deposits; the upper part is made up of red fluvial sedimentary rocks. Basic volcanic rocks occur locally throughout the sequence. The climate is inferred to have been warm and humid. The limnic (freshwater) environment had a minimum extension of 300 × 100 km. Limnic facies is inferred from the existence of fine-parallel-bedded sediments, ooliths and a limnic benthic fauna. Lake-shore deposits prevail in the outcrops. In some sections, the green limnic sequence is followed by red fine-grained floodplain or alluvial plain, and fluvial channel deposits. The framework composition of the Miembro Medio is dominated by volcanogenic detritus presumably eroded from the successions of the previous Late Carboniferous volcanic arc. Another volcanogenic clast type was provided by syndepositional basalto-andesitic phreatomagmatic activity, which also produced peperitic sills, dykes and lavas. The limnic-alluvial fan facies association, the predominance of volcanogenic detritus, and the accompanying intrabasinal basic calc-alkaline volcanism together with the considerable size of the basin point to a ?NW-SE trending half-graben setting controlled by (trans-)tensional arc tectonics. With regard to the Late Carboniferous-Triassic volcanosedimentary successions of northern Chile, this Latest Carboniferous tensional setting is the only feature in this area supporting those models, which inferred an extensional magmatic arc for the entire Central and

  14. [Nutritive value of shellfish consumed in Chile].

    Science.gov (United States)

    Pak, N; Vera, G; Araya, H

    1985-03-01

    The purpose of the present study was to determine the protein quality and digestibility of shellfish commonly consumed in Chile, and to estimate its contribution to the protein needs of the Chilean population. The shellfish studied were chorito (Mytilus edulis chilensis), macha (Mesodesma donacium), loco (Concholepas concholepas), cholga (Aulacomya ater), erizo (Loxechinus albus) and almeja (no specific variety). The NPU method was used to determine protein quality. The percentage of protein adequacy for adult rations was calculated according to FAO/WHO 1973. The contribution of shellfish to the protein availability according to the family income of the Santiago population, was also calculated. Most of the shellfish presented NPU values of about 70; the lowest values were found for loco (54.9) and macha (63.3). The apparent and true digestibility gave an average of 83.6 and 90.4, respectively. The percentage of protein adequacy of habitual rations ranged between 27% (erizo) and 58% (loco). The availability of shellfish protein in relation to total protein increased from 0.4 to 2.5% when income increased. It is concluded therefore, that shellfish protein is, in general, of good quality. Nevertheless, it might be considered of poor influence insofar as fulfilling the protein needs of the population studied, whatever its socioeconomic level. PMID:3834878

  15. Financiamiento Solidario para Vivienda en Chile

    Directory of Open Access Journals (Sweden)

    Mauricio Rojas Mujica

    2007-01-01

    Full Text Available El Programa de Desarrollo Solidario (PDS del Banco del Desarrollo consiste en brindar apoyo financiero y formativo a mujeres de escasos recursos a lo largo de todo Chile, a través de un crédito solidario, sin ningún otro tipo de garantía que la confianza, la responsabilidad y la solidaridad. En este Programa se trabaja con grupos de al menos 8 mujeres de muy escasos recursos que no tienen acceso al sistema bancario tradicional por no contar con ingresos demostrables ni estables. El apoyo financiero se canaliza a través de créditos solidarios. El apoyo formativo consiste en un trabajo en forma previa al otorgamiento de los créditos y luego un seguimiento periódico del grupo, durante todo el periodo de reembolso del crédito. A la fecha, han participado en este programa más de 10.000 mujeres, estimándose que más de 6.000 de ellas han dedicado estos préstamos al mejoramiento de la calidad de su vivienda, movilizando en forma directa más de 2 millones de dólares.

  16. Estudio hidrogeoquímico en la cuenca altiplánica de Pampa Lirima, Andes Centrales (Chile)

    OpenAIRE

    Achurra, Luciano; Custodio Gimena, Emilio; Aguirre, Igor; Arcos, Rodrigo; Clavero, Jorge

    2011-01-01

    La cuenca de Pampa Lirima se ubica en el límite occidental del Altiplano. Las cumbres y zonas elevadas (4200-5800 msnm) de la cuenca se componen de rocas volcánicas del Oligoceno a Plioceno, donde localmente se desarrollan acuíferos colgados y acuitardos en los sectores afectados por alteración hidrotermal. En la zona central más deprimida (4000-4200 msnm) la cuenca está rellena de depósitos aluviales y pluvioglaciales, que forman un acuífero intergranular libre y artesiano en sectores pun...

  17. Tectonic controls and Cenozoic magmatism at the Torres del Paine, southern Andes (Chile, 51°10'S)

    OpenAIRE

    Uwe Altenberger; Roland Oberhänsli; Benita Putlitz; Klaus Wemmer

    2003-01-01

    Five Miocene intrusive complexes are located along the N-trending, nearly trench-parallel San Lorenzo-Balmaceda Lineament in southern Patagonia. These complexes are characterized by mildly alkaline to calc-alkaline magmatism. The deformation and kinematics in the foreland of the granitoid-dominated Torres del Paine laccolith (12±2 Ma) were studied in order to evaluate the influence of the pre- to syn-intrusive crustal stress field on magma emplacement. Compression and transpression led to lar...

  18. Capitulo 11. Inseguridad, disturbios y violencia en los Andes

    OpenAIRE

    Dollfus, Olivier

    2014-01-01

    La violencia en la historia Que los Andes hayan sido lugares de violencia en el transcurso de los siglos no tiene nada de sorprendente; es ahí donde se encontraban los hombres o por lo menos la mayoría de ellos, es ahí donde estallaban los conflictos y se resolvían después de batallas y represiones. Guerras de la Conquista, donde en cada campo se encontraban indios y hasta españoles a veces; rebeliones “indias” del fin del siglo xviii, de Túpac Amaru en la región del Cusco a Túpac Katari en e...

  19. Large amplitude waves detected with balloons near the Andes Mountains

    Science.gov (United States)

    de la Torre, A.; Alexander, P.; Giraldez, A.

    Spectral results from a vertical sounding of temperature and wind velocity performed with an open stratospheric balloon in Argentina near the Andes mountains between 12 and 25 km of altitude, are reported. The use of sonic anemometers allows for a higher resolution than in previous experiments. The data records are studied in successive subintervals, yielding a good spectral correlation between the ascent and the descent around and below the tropopause. The possibilities of an orographic origin for large amplitude modes observed in the spectra and of wave generation by non linear interactions between them are discussed.

  20. Mujeres de los andes: condiciones de vida y salud

    OpenAIRE

    Defossez, Anne-Claire; Bassin, Didier; Viveros, Mara; Sánchez Parga, José; Vaca Bucheli, Rocío; Llanos Cervantes, Elvira; Li, Dina; Urra Giraldo, Fernando; Zapata Arteaga, Diego; Poloni, Jacques; Moscoso, Martha; Bejarano, Nilse; Arango, Luz Gabriela; Palomino, Nancy; Borchart de Moreno, Cristiana

    1992-01-01

    El Seminario "Mujeres de los Andes: condiciones de vida y salud" tuvo lugar en la ciudad de Quito, del 6 al 10 de junio de 1991, reunió investigadores de distintas disciplinas académicas y actores de variados campos, de cuatro países del área andina Bolivia, Colombia, Ecuador y Perú-, en los cuales está presente el Instituto Francés de Estudios Andinos, principal instigador del evento. Este libro, que reúne la mayor parte de las ponencias en él presentadas, se inscribe en la línea de las cor...

  1. The largest holocene eruption of the Central Andes found

    OpenAIRE

    Fernandez-Turiel, J. L.; J. Saavedra; Perez-Torrado, J. F.; Rodriguez-Gonzalez, A.; Carracedo, Juan Carlos; Osterrieth, M.; Carrizo, J. I.; Esteban, G.

    2013-01-01

    We present new data and interpretation about a major eruption -spreading 110 km3 ashes over 440.000 km2- long thought to have occurred around 4200 years ago in the Cerro Blanco Volcanic Complex (CBVC) in NW Argentina. This eruption may be the biggest during the past five millennia in the Central Volcanic Zone of the Andes, and possibly one of the largest Holocene eruptions in the world. The environmental effects of this voluminous eruption are still noticeable, as evidenced by the high conte...

  2. Giant evaporite belts of the Neogene central Andes

    Science.gov (United States)

    Alonso, Ricardo N.; Jordan, Teresa E.; Tabbutt, Kenneth T.; Vandervoort, Dirk S.

    1991-04-01

    Large volumes of continental evaporites accumulated within the central Andes during Neogene uplift of the Altiplano-Puna plateau and development of the Andean volcanic arc. Halite and gypsum are dominant minerals, along with local and economically important borates. Playa conditions have existed since ca. 15 Ma; halite and borate deposition has occurred for the past 7 to 8 m.y. Evaporites formed in salar environments (e.g., playa lakes) and are characterized by complex mineral assemblages, occurrence, zonation, and geochemistry. Evaporite deposition was controlled by volcanism, geothermal activity, closed drainage, and climate. These Andean deposits, and their controls, differ from evaporites in other continental and marine environments.

  3. Desde los Andes al Orinoco y al Amazonas

    OpenAIRE

    Duque Escobar, Gonzalo

    2015-01-01

    La Orinoquia y la Amazonia con su considerable red hídrica natural y cadena de valor, esperan ver consolidadas dos rutas que pasando por los Andes articulen el Atlántico y el Pacífico, conformando dos corredores logísticos que avanzarían a Bogotá por el río Meta y a Quito por el río Napo; proyectos vitales para la integración de América del Sur y para la identidad y desarrollo de dichas regiones que comprenden el 46,7 % de la superficie sudamericana

  4. Ophiolites in the Eastern Cordillera of the central Peruvian Andes

    OpenAIRE

    Castroviejo Bolibar, Ricardo; Rodrigues, Feliciano; Tassinari, Colombo G.; Pereira, Eurico; Acosta, Jorge

    2010-01-01

    A discoutinuous NNW-SSE trending belt of scattered ultraiuafic (UM) and subordínate mafic (M) rocks ís exposed alona some 250 km in the Eastern Cordillera of the peruvian Andes (Junin and Huanuco Departnients. -°"-12° S). New data questiou tlieír pieviousty assuuned [1.2] intrusive origin. Work, in progress shows tLat the essential geologic and tecronk featiires are comnion to most of them, as will t e shown on the southeniniost occurrences: Tapo and Acobaniba (Tarraa proviuce). The Tapo mass...

  5. Tamaños de muestra para estimar la estructura de tallas de las capturas de langostino colorado en la zona centro-norte de Chile: una aproximación a través de remuestreo Sample sizes for estimating the catch size distribution of squat lobster in north-central Chile: a resampling approach

    Directory of Open Access Journals (Sweden)

    Carlos Montenegro Silva

    2009-01-01

    Full Text Available Se analizó el desempeño de distintos tamaños de muestra para estimar la composición de tallas de las capturas del langostino colorado (Pleuroncodes monodon, a partir de un procedimiento de remuestreo computacional. Se seleccionaron datos recolectados en mayo de 2002 entre los 29°10'S y 32°10'S. A partir de éstos, se probaron siete escenarios de muestreo de viajes de pesca (1-7 viajes, 12 escenarios de número de ejemplares muestreados (25, 50,...300, cada 25 ejemplares y dos estrategias de muestreo de lances de pesca al interior de un viaje de pesca (censo de lances y muestreo sistemático. Se probó la combinación de todos estos escenarios, lo que permitió analizar el desempeño de 168 escenarios de tamaño de muestra para estimar la composición de tallas por sexo. Los resultados indicaron una disminución en el índice de error en la estimación de la distribución de frecuencia de tallas, conforme aumentó el número de viajes de pesca, con disminuciones progresivamente menores entre escenarios adyacentes. Del mismo modo, se verificó una disminución en el índice de error al aumentar el número de ejemplares muestreados, con mejoras marginales sobre los 175 ejemplares.The performances of different sample sizes for estimating the size distribution of squat lobster (Pleuroncodes monodon catches were analyzed using a computer resampling procedure. The data selected were gathered in May 2002 between 29°10'S and 32°10'S. These data were used to test seven sampling scenarios for fishing trips (1-7 trips, twelve scenarios of the number of individuals sampled per tow (25, 50,..., 300, and two within-trip sampling strategies (sampling all tows and systematic tow sampling. By testing the combination of all these scenarios, we were able to analyze the performance of 168 scenarios of sample size for estimating the composition of sizes by sex. The results indicate a lower error index for estimates of the size frequency distribution as the

  6. Village microgrids: The Chile project

    Energy Technology Data Exchange (ETDEWEB)

    Baring-Gould, E.I.

    1997-12-01

    This paper describes a village application in Chile. The objective was to demonstrate the technical, economic and institutional viability of renewable energy for rural electrification, as well as to allow local partners to gain experience with hybrid/renewable technology, resource assessment, system siting and operation. A micro-grid system is viewed as a small village system, up to 1200 kWh/day load with a 50 kW peak load. It can consist of components of wind, photovoltaic, batteries, and conventional generators. It is usually associated with a single generator source, and uses batteries to cover light day time loads. This paper looks at the experiences learned from this project with regard to all of the facets of planning and installing this project.

  7. Chile2015: Lévy Flight and Long-Range Correlation Analysis of Earthquake Magnitudes in Chile

    Science.gov (United States)

    Beccar-Varela, Maria P.; Gonzalez-Huizar, Hector; Mariani, Maria C.; Serpa, Laura F.; Tweneboah, Osei K.

    2016-06-01

    The stochastic Truncated Lévy Flight model and detrended fluctuation analysis (DFA) are used to investigate the temporal distribution of earthquake magnitudes in Chile. We show that Lévy Flight is appropriated for modeling the time series of the magnitudes of the earthquakes. Furthermore, DFA shows that these events present memory effects, suggesting that the magnitude of impeding earthquakes depends on the magnitude of previous earthquakes. Based on this dependency, we use a non-linear regression to estimate the magnitude of the 2015, M8.3 Illapel earthquake based on the magnitudes of the previous events.

  8. Near-surface temperature lapse rates in a mountainous catchment in the Chilean Andes

    Science.gov (United States)

    Ayala; Schauwecker, S.; Pellicciotti, F.; McPhee, J. P.

    2011-12-01

    In mountainous areas, and in the Chilean Andes in particular, the irregular and sparse distribution of recording stations resolves insufficiently the variability of climatic factors such as precipitation, temperature and relative humidity. Assumptions about air temperature variability in space and time have a strong effect on the performance of hydrologic models that represent snow processes such as accumulation and ablation. These processes have large diurnal variations, and assumptions that average over longer time periods (days, weeks or months) may reduce the predictive capacity of these models under different climatic conditions from those for which they were calibrated. They also introduce large uncertainties when such models are used to predict processes with strong subdiurnal variability such as snowmelt dynamics. In many applications and modeling exercises, temperature is assumed to decrease linearly with elevation, using the free-air moist adiabatic lapse rate (MALR: 0.0065°C/m). Little evidence is provided for this assumption, however, and recent studies have shown that use of lapse rates that are uniform in space and constant in time is not appropriate. To explore the validity of this approach, near-surface (2 m) lapse rates were calculated and analyzed at different temporal resolution, based on a new data set of spatially distributed temperature sensors setup in a high elevation catchment of the dry Andes of Central Chile (approx. 33°S). Five minutes temperature data were collected between January 2011 and April 2011 in the Ojos de Agua catchment, using two Automatic Weather Stations (AWSs) and 13 T-loggers (Hobo H8 Pro Temp with external data logger), ranging in altitude from 2230 to 3590 m.s.l.. The entire catchment was snow free during our experiment. We use this unique data set to understand the main controls over temperature variability in time and space, and test whether lapse rates can be used to describe the spatial variations of air

  9. 1960 Puerto Montt, Valdivia, Chile Images

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — On May 22, 1960, a Mw 9.5 earthquake, the largest earthquake ever instrumentally recorded, occurred in southern Chile. The series of earthquakes that followed...

  10. Report on the ESO Chile Science Days

    Science.gov (United States)

    West, Michael

    2008-03-01

    Science Days in Santiago are an annual gathering of ESO's geographically dispersed team in Chile to learn more about each other's research, to celebrate scientific achievements of the past year and to encourage new collaborations.

  11. Surface Observations from Punta Arenas, Chile

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Surface Observations from Punta Arenas, in extreme southern Chile. WMO station ID 85934. Period of record 1896-1954. The original forms were scanned at the Museo...

  12. Biomonitoring air pollution in Chile

    International Nuclear Information System (INIS)

    Full text: Chile, in general, and Santiago, its capital city, in particular, has serious air pollution problems mainly in winter time when the pollutants could reach dangerous levels which might be detrimental to older people and children. A project was undertaken within the framework of a Co-ordinated Research Programme (CRP) supported by the International Atomic Energy Agency (IAEA) to carry out a long term study on atmospheric air pollution in Chile using biomonitors. The present paper describes the activities carried out within this CRP. The lichens, collected in clean areas (native forests), were transplanted to selected sites in Santiago and exposed during three and six months. At a second stage, samples of Tillandsia recurvata were collected in the Metropolitan Area. All samples were carefully cleaned, using only clean plastic materials, milled at liquid nitrogen temperature, freeze dried, re-homogenized and stored at low temperature until analysis. The samples were mainly analysed by INAA, RNAA SS-AAS and ASV. As part of the routine QA/QC programme, analytical laboratories involved in the project participated in intercomparison runs organized by the IAEA for the determination of trace and minor elements in two lichens samples. From the data and its subsequent mapping over the area under study, it was possible to identify places exposed to higher amounts of some elements. Of interest are also the correlations between several elements, perhaps indicating a given source of pollutants. The results indicate the usefulness of biomonitoring air pollution using lichens and Tillandsias, which, jointly with multielemental analytical techniques, such as NAA, open the possibility to study extensive areas without the infrastructure needed for conventional APM sample collection and at reduced costs. (author)

  13. Hemophilia in Chile, 1996-2006

    OpenAIRE

    Mario Donoso Scroppo

    2013-01-01

    This article describes the process that Chile underwent from 1996 to 2006, which is the dawn of a period of planned and systematic organization that begins to solve the severe health problems that afflict patients with hemophilia. The article reports a general overview of the situation of hemophilia in Chile in that period – up to 2006 - , including the lack of reliable data, treatment options, training of specialists on the topic and healthcare system responses. The article then goes on to d...

  14. Enterprise Surveys : Chile Country Profile 2010

    OpenAIRE

    World Bank; International Finance Corporation

    2011-01-01

    The Country Profile for Chile is based on data from the Enterprise Surveys conducted by the World Bank. The benchmarks include the averages for the group of countries in Latin America & Caribbean and the Chile income group. The enterprise surveys focus on the many factors that shape the decisions of firms to invest. These factors can be accommodating or constraining and play an important r...

  15. Chile ushers in new hydro era

    International Nuclear Information System (INIS)

    The planned construction of two hydroelectric power plants at Peuchen and Mampil, will help to meet Chile's growing electricity demand. Securing finance for the project has been straight forward thanks to the optimal hydrological conditions, rivers with a very strong flow providing a large head of water over short distance. Hydropower plays a central role in Chile's generating capacity providing 70% of total energy consumption. Thus, the future of these projects will be highly successful, it is argued. (UK)

  16. Desigualdad geográfica en Chile

    OpenAIRE

    Agostini, Claudio A.; Brown, Philip H.

    2007-01-01

    Despite success in reducing poverty over the last twenty years, inequality in Chile has remained virtually unchanged, making Chile one of the least equal countries in the world. High levels of inequality have been shown to hamper further reductions in poverty as well as economic growth and local inequality has been shown to affect such outcomes as violence and health. The study of inequality at the local level is thus crucial for understanding the economic well-being of a country. Local measu...

  17. Trade and Integration Sector Note: Chile

    OpenAIRE

    Mauricio Mesquita Moreira

    2006-01-01

    This Trade and Integration Sector Note addresses a few different factors for trade in Chile: export diversification, trade and regional disparities, preferential agreements, trade and transport costs. The final section looks beyond the conventional tariff and non tariff-barriers to trade, and focuses on the role of transport costs. Given Chile's low tariff and non-tariff barriers and its network of trade agreements, the reduction of non-conventional trade costs are bound to offer the best ret...

  18. Late Pleistocene to Holocene tephrostratigraphy of the Lonquimay Volcano, South Central Chile

    Science.gov (United States)

    Gilbert, D.; Freundt, A.; Kutterolf, S.; Burkert, C.

    2010-12-01

    The Lonquimay Volcanic Complex (LVC) in South Central Chile (38.38°S, 71.58°W) is part of the Southern Volcanic Zone of the Andes, which formed in response to the subduction of the Nazca Plate beneath the South American Plate. During the course of its magmatic evolution, the LVC produced explosive eruptions documented in the succession of widespread tephra deposits, as well as large lava flows that originated from the main edifice and several adjacent minor eruptive centers. The last eruptive phase in Lonquimays volcanic evolution occurred from 1988-1990. It led to the formation of the Navidad cinder cone with its associated 10.2 km long lava flow, and a widely distributed tephra blanket of andesitic composition (Moreno and Gardeweg, 1989). During recent field work we reinvestigated and complemented the LVC tephrostratigraphy as originally established by Polanco (1998)by detailed logging of 22 outcrops and collecting 126 stratigraphically controlled samples that were analyzed for their matrix glass, mineral and bulk rock compositions. This data set allows us to verify and extend the field-based correlations, and to establish a tephrostratigraphy for the LVC that comprises 15 stratigraphic units (LQA-LQO) and provides a framework for ongoing investigations of the petrogenetic evolution of the LVC. The stratigraphic record identifies at least 13 explosive eruptions of VEI > 3 that occurred since the last glaciation period (17150 a BP, McCulloch et al. 2000). Magmatic compositions of the tephra deposits range from basaltic scoriae (51wt% SiO2) to evolved dacitic pumice lapilli layers (67wt% SiO2), and thus have a wider compositional range than the chemically distinct andesitic lavas (57-63wt%) of the LVC. The vertical succession of tephra compositions reflects four periods of progressive magmatic differentiation, each successively tapped by several eruptions. The maximum degree of fractionation reached during these periods increases to younger ages. The

  19. Investigating links between climate and orography in the central Andes: Coupling erosion and precipitation using a physical-statistical model

    Science.gov (United States)

    Lowman, Lauren E. L.; Barros, Ana P.

    2014-06-01

    Prior studies evaluated the interplay between climate and orography by investigating the sensitivity of relief to precipitation using the stream power erosion law (SPEL) for specified erosion rates. Here we address the inverse problem, inferring realistic spatial distributions of erosion rates for present-day topography and contemporaneous climate forcing. In the central Andes, similarities in the altitudinal distribution and density of first-order stream outlets and precipitation suggest a direct link between climate and fluvial erosion. Erosion rates are estimated with a Bayesian physical-statistical model based on the SPEL applied at spatial scales that capture joint hydrogeomorphic and hydrometeorological patterns within five river basins and one intermontane basin in Peru and Bolivia. Topographic slope and area data were generated from a high-resolution (˜90 m) digital elevation map, and mean annual precipitation was derived from 14 years of Tropical Rainfall Measuring Mission 3B42v.7 product and adjusted with rain gauge data. Estimated decadal-scale erosion rates vary between 0.68 and 11.59 mm/yr, with basin averages of 2.1-8.5 mm/yr. Even accounting for uncertainty in precipitation and simplifying assumptions, these values are 1-2 orders of magnitude larger than most millennial and million year timescale estimates in the central Andes, using various geological dating techniques (e.g., thermochronology and cosmogenic nuclides), but they are consistent with other decadal-scale estimates using landslide mapping and sediment flux observations. The results also reveal a pattern of spatially dependent erosion consistent with basin hypsometry. The modeling framework provides a means of remotely estimating erosion rates and associated uncertainties under current climate conditions over large regions. 2014. American Geophysical Union. All Rights Reserved.

  20. Heinrich I and Younger Dryas Glaciation in the Central Andes

    Science.gov (United States)

    Zech, J.; Zech, R.; May, J.; Kubik, P. W.; Veit, H.

    2009-12-01

    Short term climate reversals, such as Heinrich I (H-I) and the Younger Dryas (YD), are well documented in the Northern Hemisphere. However, the respective response of the climate system in the Southern Hemisphere during these events remains enigmatic. Here we present 10Be surface exposure ages from the Wara Wara Valley (17°S, 66°W), Cordillera Cochabamba, that reveal glacial advances in the Central Andes before 14.3 ka and 11.9 ka. These advances correlate with H-I and YD and coincide with the lake transgression phases Tauca (18-14 ka) and Coipasa (13-11 ka) on the Altiplano. They corroborate the precipitation sensitivity of glacier mass balances in the semi-arid Central Andes. We suggest that sufficient moisture for glacial advances can be explained by enhanced upper tropospheric easterlies as a response to an intensified tropical circulation and sustained la Niña like patterns in the eastern Pacific. This redistribution of the ocean and atmospheric circulation was caused by a southward shift of the ITCZ due to northern hemispheric cooling. At 10.8 ka glacier advanced again attributed to increased moisture supply by enhanced polar advection and SE trade winds during the Early Holocene. Final deglaciation started only at 9.2 ka induced by a change to drier conditions.

  1. Asynchronous Glacial Chronologies in the Central Andes (15-40°S) and Paleoclimatic Implications

    Science.gov (United States)

    Zech, R.; Kull, C.; Kubik, P. W.; Veit, H.

    2006-12-01

    We have established glacial chronologies along a N-S transect over the Central Andes using 10Be surface exposure dating. Our results show that maximum glacial advances occurred asynchronously and reflect the varying influence and shifts of the major atmospheric circulation systems during the Late Quaternary: the tropical circulation in the north and the westerlies in the south. In Bolivia (three research areas in the Cordillera Real and the Cordillera Cochabamba, ~15°S) glacial advances could be dated to ~20 and 12 ka BP. This is in good agreement with published exposure age data from moraines in Bolivia and Peru (provided that all ages are calculated following the same scaling system). Accordingly, the maximum glaciation there probably occurred roughly synchronous to the temperature minimum of the global Last Glacial Maximum (LGM) and the lateglacial cold reversals. Strict correlation with neither the Younger Dryas in the northern hemisphere, nor the Antarctic Cold Reversal is possible due to the current systematic exposure age uncertainties (~10%). Glacier-Climate-Modelling corroborates the sensitivity of the reconstructed glaciers to temperature changes, rather than precipitation. On the contrary, there is good evidence for the dominant role of precipitation changes on the glacial chronologies in the lee of the Cordillera Occidental, i.e. on the Altiplano and further south. The pronounced lateglacial wet phase, which is well documented in lake transgression phases as far south as 28°S (-> tropical moisture source), seems to have caused glacial advances even at ~30°S. In two research areas in Chile at that latitude, we were able to date several lateglacial moraines. Besides, the maximum datable glaciation there occurred at ~30 ka BP. That is significantly earlier than the LGM (sensu strictu) and points to favourable climate conditions for glaciation at that time (particularly increased precipitation). We conclude that the westerlies were more intensive or

  2. A glaciological baseline for the upper Olivares basin, Chilean Central Andes

    Science.gov (United States)

    Loriaux, T.; Bown, F.; Burger, F.; Cisternas, S.; Gacitúa, G.; Hernández, J.; Malmros, J.; Muñoz, C.; Oberreuter, J.; Rivera, A.; Silva, R.

    2013-12-01

    Santiago de Chile, with near 6.7 million of inhabitants, is located at the foot of the Andes, in the Maipo river basin, where there are approximately 424 km2 of ice, being the biggest glaciers, those located at the upper Olivares basin. Very little has been researched in recent years about the ongoing changes taking place in the area or about the glacier meltwater contribution or about the human impact on the glaciers. In order to tackle this deficiency, we began a research program in 2012, aiming to complete a glaciological baseline for this area, including glacier mass, energy and hydrological studies. For this purpose, we have established a detailed monitoring program on two glaciers where we installed 3 automatic weather stations, two arrays of stakes for mass balance studies, two automatic photographic cameras for monitoring albedo changes and two runoff stations, among several other instruments. Also, we have surveyed 5 glaciers with our airborne radar and lidar systems, allowing mapping their surface topographies at different seasons and the bedrocks underneath the ice. Analysis of satellite images shows generalized glacier area shrinkage, with a mean area lost of 25.5% since 1967 (total of 68.6 km2 in 1967 among 6 studied glaciers). The collected radar ice thickness data (maximum ice thickness of 223 m), allowed calculating a total volume of water equivalent of 3 km3 storage in 5 main glaciers of the basin. The GPS surveys of several stakes resulted in surface ice velocities between 1 and 5 m/yr. The mass balance studies showed high summer ablation rates, with an important role of sublimation, expressed as penitentes with heights of up to 1.5 m. Runoff contributed by Olivares Alfa glacier averaged 461 l/s between January and April 2013 with peaks of up to 2000 l/s, confirming the importance of glacier meltwater for the basin during summer months (January-March). The above numbers are some of the results obtained in the area, illustrating the importance of

  3. VariaciOn morfolOgica de Phacelia secunda J.F. Gmel. (Hydrophyllaceae a lo largo de un gradiente a ltitudinal en Chile central Morphological variation of Phacelia secunda J.F. Gmel. (Hydrophyllaceae along an altitudinal gradient in central Chile

    Directory of Open Access Journals (Sweden)

    Lohengrin A. Cavieres

    2000-01-01

    Full Text Available Phacelia secunda J.F. Gmel. (Hydrophyllaceae es una hierba perenne que en Chile, y también en Argentina, presenta una amplia distribución, habitando desde Parinacota (18°S hasta Tierra del Fuego (54°S, y desde el nivel del mar hasta la alta cordillera. En este estudio se documentan algunas variaciones morfológicas que presenta esta especie a lo largo de un gradiente altitudinal desde los 1.600 m a los 3.400 m en los Andes de Chile central (33°S. Se encontró que el diámetro de las rosetas aumenta significativamente con la altitud, al igual que el número de inflorescencias por individuo y la longitud de la pubescencia. Por el contrario, la altura de las inflorescencias disminuye con la altitud. La tendencia a privilegiar el crecimiento vertical a bajas altitudes y el crecimiento horizontal en altitudes mayores sería una respuesta adaptativa a las frías condiciones de los ambientes de alta montaña. Del mismo modo, el aumento en la longitud de la pubescencia con la altitud sería una adaptación para mantener un balance térmico positivo y evitar los excesos de radiación en dichos ambientesPhacelia secunda J.F. Gmel. (Hydrophyllaceae is a perennial herb that both, in Chile and Argentina, shows a wide distributional range, inhabiting from Parinacota (18°S to Tierra del Fuego (54°S, and from the sea level up to the high Andes. In this study some morphological variations along an altitudinal gradient from 1600 to 3400 m in Andes of central Chile (33°S are reported. The diameter of the rosettes significantly increased with elevation, as well as the number of inflorescences per individual and the longitude of pubescence. In contrast, the height of inflorescences decreased with elevation. Tendencies for privileging vertical growth at lower elevations and horizontal growth at higher elevations would be adaptations to the cold and harsh climate of high mountain habitats. In a similar vein, the increase in the longitude of pubescence with

  4. Methods to Estimate Lettuce Evapotranspiration in Greenhouse Conditions in the Central Zone of Chile Métodos de Estimación de la Evapotranspiración de un Cultivo de Lechuga en Condiciones de Invernadero, Zona Central de Chile

    Directory of Open Access Journals (Sweden)

    Manuel Casanova P

    2009-03-01

    Full Text Available This study evaluates five methods to estimate crop evapotranspiration in greenhouse conditions. It compares their performance in relation to the evapotranspiration directly determined from water balance measurements (ETlys in an irrigated lettuce (Lactuca sativa L. crop during 9 weeks. Daily values of the reference evapotranspiration (ETo from Class A pan (CAP, Piche atmometers (ATM, Andersson evaporimeters (ANE, FAO-Radiation (FRE and FAO-Penman-Monteith (PME equations were compared. The methods showed similar temporal variations but at different ranges as follows: ANE Este estudio evalúa cinco métodos de estimación de la evapotranspiración de cultivos en condiciones de invernadero. Sus desempeños se evalúan en base a la evapotranspiración determinada directamente a partir de mediciones de balance hídrico (ETlys, para un cultivo de lechuga (Lactuca sativa L. bajo riego y un período de 9 semanas. Se compararon los valores diarios de evapotranspiración de referencia (ETo provenientes de una bandeja clase A (CAP, atmómetros de Piche (ATM, evaporímetros Andersson (ANE, la ecuación FAO-Radiación (FRE y la ecuación FAO-Penman-Monteith (PME. Los métodos muestran similares variaciones en el tiempo, pero en los diferentes rangos siguientes: ANE < CAP < FRE < PME < ATM. Además, ETo muestra una clara correlación con la radiación solar. Los coeficientes de cultivo (Kc = ETlys/ETo variaron entre métodos pero se identificaron tendencias para dos períodos: en la primera semana el Kc promedio fue de 0,3 (± 0,1 y dentro de las semanas 2 a 9 estos valores fueron del orden de 0,6 (± 0,3. Los valores de Kc encontrados en invernadero fueron inferiores a los adoptados para lechuga en condiciones de campo. En términos de diseño de riego, la evapotranspiración del cultivo puede ser estimada si se emplean los métodos de este estudio, con la salvedad que se apliquen los coeficientes de cultivo apropiados. El hecho que ANE muestre los valores m

  5. The GalileoMobile starts its South American voyage - Astronomy education goes on tour through the Andes Mountains

    Science.gov (United States)

    2009-10-01

    Today marks the beginning of the GalileoMobile Project, a two-month expedition to bring the wonder and excitement of astronomy to young people in Chile, Bolivia and Peru. Supported by ESO and partners, a group of astronomers and educators will travel through a region of the Andes Mountains aboard the GalileoMobile, offering astronomical activities, such as workshops for students and star parties for the general public. Professional filmmakers on the trip will produce a multilingual documentary capturing the thrill of discovery through science, culture and travel. The GalileoMobile is a Special Project of the International Year of Astronomy 2009 (IYA2009), which is a global celebration commemorating the first use of a telescope to view the Universe by the Italian astronomer Galileo four hundred years ago. The project will promote basic science education through astronomy by visiting schools and communities that have limited access to outreach programmes. The GalileoMobile will provide these underserved groups with hands-on activities and educational material from international partners. The van is fully equipped to offer unique sky-observing opportunities for young students and other locals, with star parties at night and solar observations during the day. The team will use various tools including IYA2009's handy Galileoscopes, which will be donated to the schools after the visits. By stimulating curiosity, critical thinking and a sense of wonder and discovery for the Universe and our planet, the GalileoMobile Project aims to encourage interest in astronomy and science, and exchange culturally different visions of the cosmos. Spearheading the initiative is a group of enthusiastic Latin American and European PhD students from the European Southern Observatory, the Max Planck Society, the University Observatory Munich, and the Stockholm University Observatory. This itinerant educational programme is intended to reach about 20 000 people during eight weeks in October

  6. Prevalence and correlates of physical fighting among school-going adolescents in Santiago, Chile Prevalencia e correlaciones de la lucha física entre adolescentes escolares en Santiago de Chile, Chile

    OpenAIRE

    Emmanuel Rudatsikira; Muula, Adamson S; Seter Siziya

    2008-01-01

    OBJECTIVE: There is a growing interest in injury as a public health issue across the world. There is paucity of data on the prevalence and social correlates of non-fatal interpersonal violence in low- and middle-income income nations. The objective of this study was to estimate the prevalence of, and associated factors for physical fighting among school-going adolescents in Santiago, Chile. METHOD: We conducted a secondary analysis of the Chilean Global School-Based Health Survey conducted in...

  7. Direction and timing of uplift propagation in the Peruvian Andes deduced from molecular phylogenetics of highland biotaxa

    Science.gov (United States)

    Picard, Damien; Sempere, Thierry; Plantard, Olivier

    2008-07-01

    Physical paleoaltimetric methods are increasingly used to estimate the amount and timing of surface uplift in orogens. Because the rise of mountains creates new ecosystems and triggers evolutionary changes, biological data may also be used to assess the development and timing of regional surface uplift. Here we apply this idea to the Peruvian Andes through a molecular phylogeographic and phylochronologic analysis of Globodera pallida, a potato parasite nematode that requires cool temperatures and thus thrives above 2.0-2.5 km in these tropical highlands. The Peruvian populations of this species exhibit a clear evolutionary pattern with deeper, more ancient lineages occurring in Andean southern Peru and shallower, younger lineages occurring progressively northwards. Genetically diverging G. pallida populations thus progressively colonized highland areas as these were expanding northwards, demonstrating that altitude in the Peruvian Andes was acquired longitudinally from south to north, i.e. in the direction of decreasing orogenic volume. This phylogeographic structure is recognized in other, independent highland biotaxa, and point to the Central Andean Orocline (CAO) as the region where high altitudes first emerged. Moreover, molecular clocks relative to Andean taxa, including the potato-tomato group, consistently estimate that altitudes high enough to induce biotic radiation were first acquired in the Early Miocene. After calibration by geological and biological tie-points and intervals, the phylogeny of G. pallida is used as a molecular clock, which estimates that the 2.0-2.5 km threshold elevation range was reached in the Early Miocene in southernmost Peru, in the Middle and Late Miocene in the Abancay segment (NW southern Peru), and from the latest Miocene in central and northern Peru. Although uncertainties attached to phylochronologic ages are significantly larger than those derived from geochronological methods, these results are fairly consistent with coeval

  8. Empathy in Students of Specialty in Physical Therapy, Universidad Mayor in Temuco, Chile

    OpenAIRE

    Víctor Patricio Díaz-Narváez; Domingo Salas-Alarcón; Fanny Bracho-Milic; Jaime Ocaranza-Ozímica

    2015-01-01

    Objective: To estimate empathy levels and describe the behavior of the structure of the empathy construct in kinesiology students at the Universidad Mayor in Temuco (Chile). Material and Methods: The Jefferson Scale of Medical Empathy, in its Spanish version for students (S Version), culturally validated for kinesiology students was applied. Cronbach's alpha and Tukey’s activity was estimated, as well. The means of data were compared using ANOVA Bifactorial and Duncan test. Kaiser-Meyer-Olkin...

  9. Primer registro del frutero pechinegro Pipreola lubomirskii (Aves, Cotingidae) en la vertiente occidental de los Andes

    OpenAIRE

    Letty Salinas; María Samamé; Irma Franke; Jon Fjeldså

    2013-01-01

    El frutero pechinegro, Pipreola lubomirskii, es un cotíngido registrado como raro y de distribución local en los Andes del Norte. Antes del presente registro sólo había sido reportado para la vertiente oriental del Perú y Ecuador, así como los Andes del sur de Colombia. El presente registro amplia su distribución a los bosques montañosos de la vertiente occidental de los Andes peruanos, habiéndose encontrado en los bosques nublados del valle del río Zaña, en el departamento de Cajamarca (6º50...

  10. Glacial changes and glacier mass balance at Gran Campo Nevado, Chile during recent decades

    Science.gov (United States)

    Schneider, C.; Schnirch, M.; Kilian, R.; Acuña, C.; Casassa, G.

    2003-04-01

    Within the framework of the program Global Land Ice Measurements from Space (GLIMS) a glacier inventory of the Peninsula Muñoz Gamero in the southernmost Andes of Chile (53°S) has been generated using aerial photopgrahy and Landsat Thematic Mapper imagery. The Peninsula is partly covered by the ice cap of the Gran Campo Nevado (GCN), including several outlet glaciers plus some minor glaciers and firn fields. All together the ice covered areas sum up to 260 km2. GCN forms the only major ice body between the Southern Patagonia Icefield and the Strait of Magallan. Its almost unique location in a zone affected year-round by the westerlies makes it a region of key interest in terms of glacier and climate change studies of the west-wind zone of the Southern Hemisphere. A digital elevation model (DEM) was created for the area, using aerial imagery from 1942, 1984, and 1998 and a Chilean topographic map (1: 100 000). All information was incorporated into a GIS together with satellite imagery from 1986 and 2001. Delineation of glacier inflow from the central plateau of Gran Campo Nevado was accomplished using an automatic module for watershed delineation within the GIS. The GIS served to outline the extent of the present glaciation of the peninsula, as well as to evaluate the derived historic information. The comparison of historic and recent imagery reveals a dramatic glacier retreat during the last 60 years. Some of the outlet glaciers lost more than 20% of their total area during this period. In February and March 2000 a automatic weather station (AWS) was run on a nameless outlet glacier, inofficially Glaciar Lengua, of the Gran Campo Nevado Ice Cap. From the computed energy balance, it was possible to derive degree-day factors for the Glaciar Lengua. With data from the nearby AWS at fjord coast (Bahia Bahamondes) we computed ablation for the summer seasons of 1999/2000, 2000/2001 and 2001/2002. Ablation at 450 m a.s.l. sums up to about 7 m in 1999/2000, 5.5 m in 2000

  11. Large-amplitude gravity waves above the southern Andes, the Drake Passage, and the Antarctic Peninsula

    Science.gov (United States)

    de la Torre, A.; Alexander, P.; Hierro, R.; Llamedo, P.; Rolla, A.; Schmidt, T.; Wickert, J.

    2012-01-01

    Above the southern Andes range and its prolongation in the Antarctic Peninsula, large-amplitude mountain and shear gravity waves observed with Weather Research and Forecasting (WRF) mesoscale model simulations during winter 2009 are analyzed. Two specific reasons motivated this study: (1) a decade of satellite observations of temperature fluctuations in the stratosphere, allowing us to infer that this region may be launching the largest-amplitude gravity waves into the upper atmosphere, and (2) the recent design of a research program to investigate these features in detail, the Southern Andes Antarctic Gravity wave Initiative (SAANGRIA). The simulations are forced with ERA-Interim data from the European Centre for Medium-Range Weather Forecasts. The approach selected for the regional downscaling is based on consecutive integrations with weekly reinitialization with 24 h of spin-up, and the outputs during this period are excluded from the analysis. From 1 June to 31 August 2009, five case studies were selected on the basis of their outstanding characteristics and large wave amplitudes. In general, one or two prevailing modes of oscillation are identified after applying continuous wavelet transforms at constant pressure levels and perpendicularly to the nominal orientation of the dominant wave crests. In all cases, the dominant modes are characterized by horizontal wavelengths around 50 km. Their vertical wavelengths, depending on a usually strong background wind shear, are estimated to be between 2 and 11 km. The corresponding intrinsic periods range between 10 and 140 min. In general, the estimated vertical wavelength (intrinsic period) maximizes (minimizes) around 250-300 hPa. The synoptic circulation for each case is described. Zonal and meridional components of the vertical flux of horizontal momentum are shown in detail for each case, including possible horizontal wavelengths between 12 and 400 km. Large values of this flux are observed at higher pressure

  12. Lichenometric Dating of Little Ice Age Moraines in the Cordillera Vilcabamba, Southern Peruvian Andes

    Science.gov (United States)

    Taggart, J. R.; Licciardi, J. M.

    2008-12-01

    Lateral and end moraines deposited by two valley glaciers were mapped on the south side of Nevado Tucarhuay (5910 m asl) and on the east side of Nevado Salcantay (6271 m asl) in the Cordillera Vilcabamba in the southern Peruvian Andes (~13°S latitude). The geomorphic expression of outer and inner moraine sequences in these two drainages mimics that of a previously studied pair of moraines in the upper Rio Blanco valley on the south side of Nevado Salcantay. Cosmogenic 10Be surface exposure dating has yielded ages of 9.0 ± 0.3 ka and 195 ± 24 years, respectively, for these outer and inner Rio Blanco moraines. In all three valleys, prominent outer moraines occur ~3-5 km from headwalls and inner moraine ridges are found ~2.5-3 km from headwalls. Recessional moraines found exclusively on the east side of Salcantay indicate multiple early- to late-Holocene glacier pauses, rather than continuous retreat, prior to the latest Holocene glacier readvance. Diameters of the lichen Rhizocarpon subgenus Rhizocarpon were measured on moraine boulders from the inner moraines in all three valleys. Lichen diameters on the two undated inner moraines are consistent with diameters on the inner 10Be-dated Rio Blanco moraine, which signifies similar lichenometric ages and supports synchronous glacier culminations in all three drainages during the Little Ice Age. The new lichen measurements and age estimates provide a critical link between previous lichen studies in the Cordillera Blanca to the north and in the Cordillera Real to the south, thereby increasing spatial coverage of terrestrial paleoclimate information. Moreover, the extensive lichen measurements gathered on the inner 10Be-dated Rio Blanco moraine define a new control point for the Rhizocarpon subgenus Rhizocarpon growth curve in the tropical Peruvian- Bolivian Andes, which will increase the accuracy of lichenometric age estimates in this region. 10Be exposure dating of the inner moraines in adjacent valleys is underway

  13. Remote sensing and climate data as a key for understanding fasciolosis transmission in the Andes: review and update of an ongoing interdisciplinary project

    Directory of Open Access Journals (Sweden)

    Màrius V. Fuentes

    2006-11-01

    Full Text Available Fasciolosis caused by Fasciola hepatica in various South American countries located on the slopes of the Andes has been recognized as an important public health problem. However, the importance of this zoonotic hepatic parasite was neglected until the last decade. Countries such as Peru and Bolivia are considered to be hyperendemic areas for human and animal fasciolosis, and other countries such as Chile, Ecuador, Colombia and Venezuela are also affected. At the beginning of the 1990s a multidisciplinary project was launched with the aim to shed light on the problems related to this parasitic disease in the Northern Bolivian Altiplano. A few years later, a geographic information system (GIS was incorporated into this multidisciplinary project analysing the epidemiology of human and animal fasciolosis in this South American Andean region. Various GIS projects were developed in some Andean regions using climatic data, climatic forecast indices and remote sensing data. Step by step, all these GIS projects concerning the forecast of the fasciolosis transmission risk in the Andean mountain range were revised and in some cases updated taking into account new data. The first of these projects was developed on a regional scale for the central Chilean regions and the proposed model was validated on a local scale in the Northern Bolivian Altiplano. This validated mixed model, based on both fasciolosis climatic forecast indices and normalized difference vegetation index values from Advanced Very High Resolution Radiometer satellite sensor, was extrapolated to other human and/or animal endemic areas of Peru and Ecuador. The resulting fasciolosis risk maps make it possible to show the known human endemic areas of, mainly, the Peruvian Altiplano, Cajamarca and Mantaro Peruvian valleys, and some valleys of the Ecuadorian Cotopaxi province. Nevertheless, more climate and remote sensing data, as well as more accurate epidemiological reports, have to be

  14. Trophic interactions in northern Chile upwelling ecosystem, year 1997

    Directory of Open Access Journals (Sweden)

    Mónica E Barros

    2014-11-01

    Full Text Available A food web model is constructed to describe predator-prey interactions, community structure and trophic flows in northern Chile upwelling ecosystem (18°20'S, 24°S, for the year 1997. The model is built using the Ecopath with Ecosim software version 6.4, and encompasses 21 functional groups, ranging from primary producers (phytoplankton to top predators (birds and marine mammals, the principal fishing resources and the fishery. Input parameters required to build the model were gathered from specialized literature, grey literature and our own estimates. The results indicated that the total biomass (B T was estimated at 624.7 ton km-2. The combined biomass of small pelagic fish represented 26% of B T, while the combined biomass of demersal fish represented only 0.1% of B T. These results highlight the importance of pelagic fish in this system. Predation mortality resulted to be the main source of mortality. Nevertheless, fishing mortality was important in anchovy, mackerel, common dolphinfish and jack mackerel. The mean trophic level of the fishery was estimated as 3.7, with landings sustained mainly by anchovy. Primary production required to sustain the landings (PPR was estimated at 7.5% of calculated total net primary production, which is lower than PPR estimates in other upwelling ecosystems. The average trophic transfer efficiency was 18%, which is in the range (10-20% informed for marine ecosystems. Results indicate that in 1997 the northern Chile marine ecosystem was characterized for being a system far from maturity, dominated in terms of biomass and flows by the pelagic realm.

  15. Serological Evidence of Hantavirus Infection in Apparently Healthy People from Rural and Slum Communities in Southern Chile

    Directory of Open Access Journals (Sweden)

    Claudia Muñoz-Zanzi

    2015-04-01

    Full Text Available Hantavirus disease in America has been recognizable because of its rapid progression in clinical cases, occurrence in previously healthy young adults, and high case fatality rate. Hantavirus disease has been proposed now to define the diversity of clinical manifestations. Since 1995, a total of 902 cases of hantavirus pulmonary syndrome have been reported in Chile, caused by Andes virus (ANDV, with overall fatality of 32%. This report describes the sero-epidemiology of hantavirus in apparently healthy people in rural and urban slum communities from southern Chile. Ten of 934 samples yielded a positive result resulting in a seroprevalence of 1.07% (95% confidence intervals: 0.05%–2.0%. A higher proportion of positive samples was found among individuals from rural villages (1.3% and slums (1.5% compared with farms (0.5%. Seropositivity was associated with age (p = 0.011, low education level (p = 0.006 and occupations linked to the household (homemaker, retired, or student (p = 0.016. No evidence of infection was found in 38 sigmodontinae rodents trapped in the peri-domestic environment. Our findings highlight that exposure risk was associated with less documented risk factors, such as women in slum and rural villages, and the occurrence of infection that may have presented as flu-like illness that did not require medical attention or was misdiagnosed.

  16. Inflation Uncertainty in Chile: Asymmetries and the News Impact Curve Inflation Uncertainty in Chile: Asymmetries and the News Impact Curve

    Directory of Open Access Journals (Sweden)

    Christian A. Johnson

    2002-03-01

    Full Text Available This article presents a historical analysis of inflation in Chile from 1933 to 2001, estimating generalized autoregressive heteroskedasticity models, including asymmetric extensions such as the Threshold, Quadratic and Box-Cox models. Traditional symmetric models accept the Friedman hypothesis establishing that inflation increases uncertainty. However, a more general class of asymmetric models rejects this hypothesis. This result is not valid for the asymmetric Box-Cox non linear model. Furthermore, we found that high levels of uncertainty in inflation increase the level of inflation with some lags, not rejecting the positive correlation established by Cukierman and Metzler. The News Impact Curve reflects those asymmetries. This article presents a historical analysis of inflation in Chile from 1933 to 2001, estimating generalized autoregressive heteroskedasticity models, including asymmetric extensions such as the Threshold, Quadratic and Box-Cox models. Traditional symmetric models accept the Friedman hypothesis establishing that inflation increases uncertainty. However, a more general class of asymmetric models rejects this hypothesis. This result is not valid for the asymmetric Box-Cox non linear model. Furthermore, we found that high levels of uncertainty in inflation increase the level of inflation with some lags, not rejecting the positive correlation established by Cukierman and Metzler. The News Impact Curve reflects those asymmetries

  17. The Genus Austroleptis from South Chile and Patagonia (Diptera, Rhagionidae)

    OpenAIRE

    NAGATOMI, Akira; NAGATOMI, Hisako; ナガトミ, アキラ; ナガトミ, ヒサコ; 永冨, 昭; 永冨, 尚子

    1988-01-01

    The genus Austroleptis from South Chile and Patagonia is revised and three new species are added. So, there are eight known species, five of which are from South Chile and Patagonia and three from Australia and Tasmania.

  18. Immigrant health workers in Chile: is there a Latin American "brain drain"?

    Science.gov (United States)

    Cabieses, Baltica; Tunstall, Helena

    2012-08-01

    Most research on the phenomenon of "brain drain" (one-way flow of highly skilled/educated individuals) has focused on movement between the least developed and most highly developed countries. Therefore, the significance of patterns of migration to middle-income countries such as those in Latin America is less clear. The aim of this study was to outline key features of international health worker "brain drain" to Chile to promote discussion and further research on this phenomenon as it pertains to the Latin American region. The study compared immigrant health workers living in Chile to both Chilean-born health workers and other immigrants living in Chile using a qualitative nationwide dataset (the results of Chile's 2009 National Socioeconomic Characterization Survey). Demographic, socioeconomic, and health-related variables were included in the analyses, which were weighted by population to obtain nationally representative estimates. In 2009, immigrant health workers represented 2.2% of all health personnel and 2.6% of all resident immigrants in the country. While most immigrant health workers had a universitylevel education, about 25% had only a high school-level education or less. There was no statistically significant difference between the distribution of immigrant health workers' household income and that of Chilean-born health workers. A significantly higher proportion of the immigrant group reported no entitlement to health care provision. While the results of this study do not indicate a significant international health worker "brain drain" to Chile, they do suggest distinctive patterns of migration within the Latin American region. Future studies in Chile could confirm the validity of these results, using a larger sample of immigrant health workers. PMID:23099879

  19. Control of codling moth (Cydia pomonella) using the area-wide approach in Chile

    International Nuclear Information System (INIS)

    Full text: Management of codling moth (CM) is being conducted in southern Chile using an area-wide approach and integrating different tools such us Geographic Information System (GIS), classical biological control, inundative biological control and mating disruption. The total area covers 6,000 ha, and extends from the foothills of the Andes mountains and is bordered in the south and north by rivers. Vegetation cover is predominantly pastures, pine forests and berries, including six commercial apple orchards. Codling moth control in the commercial orchards is based on chemical insecticides, mating disruption or organic practices. Many alternative hosts for CM grow in this area, mainly as ornamentals, in abandoned orchards and in gardens for self-consumption. The most important species are noncommercial apple, pear, quince, walnut and apricot. Satellite images were obtained and every alternate host tree was georeferenced and drawn on these images. Pheromone traps are being used to identify main migrant sources and to quantify migration from sources to commercial orchards. Classical biological control includes importation and release of an egg/larval parasitoid (Ascogaster quadridentata) from USA to Chile. CM is reared on artificial diet and eggs are used to increase the A. quadridentata colony and allow field releases in the 2004-2005 growing season, especially in isolated and abandoned trees. Related to inundative biological control, several strains of entomopathogenic organisms have been collected and evaluated against CM, including the fungus (Beauveria bassiana) and nematodes. In addition, a Chilean species of trichogrammatid wasps, Trichogramma nerudai and Trichogramma caccociae, have been used under an inundative approach, especially in abandoned orchards. The Chilean species T. nerudai has shown similar or better preference and laboratory performance than introduced species such as T. bactrae, T. caccociae, T. dendrolimi and T. platneri. (author)

  20. Using auto-correlations from seismic ambient noise to monitor velocity changes at Villarrica Volcano, Chile

    Science.gov (United States)

    McKee, K. F.; Waite, G. P.; Richardson, J. P.

    2012-12-01

    We used the Green's functions from auto-correlations and cross-correlations of seismic ambient noise to monitor temporal velocity changes in the subsurface at Villarrica Volcano in the Southern Andes of Chile. Campaigns were conducted from March to October 2010 and February to April 2011 with 8 broadband and 6 short-period stations, respectively. We prepared the data by removing the instrument response, normalizing with a root-mean-square method, whitening the spectra, and filtering from 1 to 10 Hz. This frequency band was chosen based on the relatively high background noise level in that range. Hour-long auto- and cross-correlations were computed and the Green's functions stacked by day and total time. To track the temporal velocity changes we stretched a 24 hour moving window of correlation functions from 90% to 110% of the original and cross correlated them with the total stack. The average increase in velocity gleaned from the auto-correlations during the 2010 array was 0.13%, as seen in the figure. Cross-correlations from station V01, near the summit, to the other stations show comparable increases in velocity. We attribute this change to the closing of cracks in the subsurface due either to seasonal snow loading or regional tectonics. In addition to the common increase in velocity across the stations, there are excursions in velocity on the same order lasting several days. Amplitude decreases as the station's distance from the vent increases suggesting these excursions may be attributed to changes within the volcanic edifice. Two occurrences are highlighted in the figure in which it is seen that the amplitudes at stations V06 and V07, the stations farthest from the vent, are smaller. Similar short temporal excursions were seen in the auto-correlations from 2011, however, there was little to no increase in the overall velocity.ercent change in velocity at Villarrica Volcano, Chile from March to October 2010 (stations offset by 0.2%)

  1. Radioactive wastes management development in Chile

    International Nuclear Information System (INIS)

    A Facility for immobilizing and conditioning of radioactive wastes generated in Chile, has recently started in operation. It is a Radioactive Wastes Treatment Plant, RWTP, whose owner is Comision Chilena de Energia Nuclear, CCHEN. A Storgement Building of Conditioned Wastes accomplishes the facility for medium and low level activity wastes. The Project has been carried with participation of chilean professionals at CCHEN and Technical Assistance of International Atomic Energy Agency, IAEA. Processes developed are volume reduction by compaction; immobilization by cementation and conditioning. Equipment has been selected to process radioactive wastes into a 200 liters drum, in which wastes are definitively conditioned, avoiding exposition and contamination risks. The Plant has capacity to treat low and medium activity radioactive wastes produced in Chile due to Reactor Experimental No. 1 operation, and annex Laboratories in Nuclear Research Centers, as also those produced by users of nuclear techniques in Industries, Hospitals, Research Centers and Universities, in the whole country. With the infrastructure developed in Chile, a centralization of Radioactive Wastes Management activities is achieved. A data base system helps to control and register radioactive wastes arising in Chile. Generation of radioactive wastes in Chile, has found solution for the present production and that of near future

  2. Meteorological conditions associated to high sublimation amounts in semiarid high-elevation Andes decrease the performance of empirical melt models

    Science.gov (United States)

    Ayala, Alvaro; Pellicciotti, Francesca; MacDonell, Shelley; McPhee, James; Burlando, Paolo

    2015-04-01

    Empirical melt (EM) models are often preferred to surface energy balance (SEB) models to calculate melt amounts of snow and ice in hydrological modelling of high-elevation catchments. The most common reasons to support this decision are that, in comparison to SEB models, EM models require lower levels of meteorological data, complexity and computational costs. However, EM models assume that melt can be characterized by means of a few index variables only, and their results strongly depend on the transferability in space and time of the calibrated empirical parameters. In addition, they are intrinsically limited in accounting for specific process components, the complexity of which cannot be easily reconciled with the empirical nature of the model. As an example of an EM model, in this study we use the Enhanced Temperature Index (ETI) model, which calculates melt amounts using air temperature and the shortwave radiation balance as index variables. We evaluate the performance of the ETI model on dry high-elevation sites where sublimation amounts - that are not explicitly accounted for the EM model - represent a relevant percentage of total ablation (1.1 to 8.7%). We analyse a data set of four Automatic Weather Stations (AWS), which were collected during the ablation season 2013-14, at elevations between 3466 and 4775 m asl, on the glaciers El Tapado, San Francisco, Bello and El Yeso, which are located in the semiarid Andes of central Chile. We complement our analysis using data from past studies in Juncal Norte Glacier (Chile) and Haut Glacier d'Arolla (Switzerland), during the ablation seasons 2008-09 and 2006, respectively. We use the results of a SEB model, applied to each study site, along the entire season, to calibrate the ETI model. The ETI model was not designed to calculate sublimation amounts, however, results show that their ability is low also to simulate melt amounts at sites where sublimation represents larger percentages of total ablation. In fact, we

  3. Lake Andes National Wildlife Refuge: Narrative report: January to April, 1951

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report summarizes activities on Lake Andes National Wildlife Refuge between January and April of 1951. Water conditions, furbearers, and maintenance...

  4. Lake Andes National Wildlife Refuge: Narrative report: January 1 through December 31, 1966

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Lake Andes NWR outlines Refuge accomplishments during the 1966 calendar year. The report begins by summarizing the weather...

  5. Narrative report: January, February, March, and April, 1963: Lake Andes National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Lake Andes NWR outlines Refuge accomplishments from January through April of 1963. The report begins by summarizing the weather...

  6. Lake Andes Wetland Management District Annual narrative report: Calendar year 1987

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Lake Andes Wetland Management District outlines District accomplishments during the 1987 calendar year. The report begins with an...

  7. Lake Andes Wetland Management District Annual narrative report: Calendar year 1984

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Lake Andes Wetland Management District outlines District accomplishments during the 1984 calendar year. The report begins with an...

  8. Lake Andes Wetland Management District Annual narrative report : Calendar year 1982

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Lake Andes Wetland Management District outlines District accomplishments during the 1982 calendar year. The report begins with an...

  9. Lake Andes Wetland Management District Annual narrative report : Calendar year 1981

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Lake Andes Wetland Management District outlines District accomplishments during the 1981 calendar year. The report begins with an...

  10. Lake Andes Wetland Management District Annual narrative report: Calendar year 1986

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Lake Andes Wetland Management District outlines District accomplishments during the 1986 calendar year. The report begins with an...

  11. Lake Andes Wetland Management District Annual narrative report: Calendar year 1983

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Lake Andes Wetland Management District outlines District accomplishments during the 1983 calendar year. The report begins with an...

  12. Lake Andes Wetland Management District: Annual narrative report: Calendar year 1992

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Lake Andes Wetland Management District outlines Refuge accomplishments during the 1992 calendar year. The report begins with a...

  13. Narrative Report : Lake Andes National Wildlife Refuge [September to December 1952

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Lake Andes National Wildlife Refuge outlines Refuge accomplishments from September through December of 1952. The report begins by...

  14. Lake Assessment Project Report, Lake Andes: Charles Mix County, South Dakota

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Lake Andes was included in the 1998 South Dakota 303(d) list as an impairment-related Total Maximum Daily Load waterbody. In 1922 Congress passed a bill that...

  15. Lake Andes Waterfowl Production Area: Narrative report: January 1 through December 31, 1967

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Lake Andes NWR- Waterfowl Production Area outlines Refuge accomplishments during the 1967 calendar year. The report begins by...

  16. Lake Andes Wetlands District: Narrative report: January 1 through December 31, 1968

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Lake Andes Wetlands District outlines Refuge accomplishments during the 1968 calendar year. The report begins by summarizing the...

  17. Narrative report: Lake Andes National Wildlife Refuge: May 1, to August 31, 1955

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Lake Andes NWR outlines Refuge accomplishments from May through August of 1955. The report begins by summarizing the weather conditions,...

  18. Lake Andes National Wildlife Refuge: Narrative report: January 1 through December 31, 1970

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Lake Andes NWR outlines Refuge accomplishments during the 1970 calendar year. The report begins by summarizing the weather...

  19. [Lake Andes National Wildlife Refuge: Narrative report: January to April, 1957

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Lake Andes NWR outlines Refuge accomplishments from January through April of 1957. The report begins by summarizing the weather...

  20. Narrative report: Lake Andes National Wildlife Refuge: May 1, to August 31, 1953

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Lake Andes NWR outlines Refuge accomplishments from May through August of 1953. The report begins by summarizing the weather conditions,...

  1. Lake Andes Wetlands District: Narrative report: January 1 through December 31, 1971

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Lake Andes Wetlands District outlines Refuge accomplishments during the 1971 calendar year. The report begins by summarizing the...

  2. Narrative report: May, June, July, and August, 1962: Lake Andes National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Lake Andes NWR outlines Refuge accomplishments from May through August of 1962. The report begins by summarizing the weather conditions,...

  3. Lake Andes Wetland District: Narrative report: January 1 through December 31, 1970

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Lake Andes Wetlands District outlines Refuge accomplishments during the 1970 calendar year. The report begins by summarizing the...

  4. Lake Andes National Wildlife Refuge: Narrative report: January 1 through December 31, 1968

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Lake Andes NWR outlines Refuge accomplishments during the 1968 calendar year. The report begins by summarizing the weather...

  5. Lake Andes [Wetland Management District]: Narrative report: January 1 through December 31, 1972

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Lake Andes Wetlands District outlines Refuge accomplishments during the 1972 calendar year. The report begins by summarizing the...

  6. Lake Andes Wetlands District: Narrative report: January 1 through December 31, 1969

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Lake Andes Wetlands District outlines Refuge accomplishments during the 1969 calendar year. The report begins by summarizing the...

  7. Narrative report: Lake Andes National Wildlife Refuge: May 1, to August 31, 1957

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Lake Andes NWR outlines Refuge accomplishments from May through August of 1957. The report begins by summarizing the weather conditions,...

  8. [Lake Andes National Wildlife Refuge: Narrative report: September to December, 1953

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Lake Andes NWR outlines Refuge accomplishments from September through December of 1953. The report begins by summarizing the weather...

  9. Narrative report: Lake Andes National Wildlife Refuge: May 1, to August 31, 1956

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Lake Andes NWR outlines Refuge accomplishments from May through August of 1956. The report begins by summarizing the weather conditions,...

  10. Lake Andes National Wildlife Refuge: Narrative report: January 1 through December 31, 1969

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Lake Andes NWR outlines Refuge accomplishments during the 1969 calendar year. The report begins by summarizing the weather...

  11. Narrative report: September, October, November, and December, 1962: Lake Andes National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Lake Andes NWR outlines Refuge accomplishments from September through December of 1962. The report begins by summarizing the weather...

  12. Narrative report: Lake Andes National Wildlife Refuge: May 1, to August 31, 1954

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Lake Andes NWR outlines Refuge accomplishments from May through August of 1954. The report begins by summarizing the weather conditions,...

  13. Narrative report: January 1 through December 31, 1964: Lake Andes National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Lake Andes NWR outlines Refuge accomplishments during the 1964 calendar year. The report begins by summarizing the weather...

  14. Lake Andes National Wildlife Refuge: Narrative report: January 1 through December 31, 1971

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Lake Andes NWR outlines Refuge accomplishments during the 1971 calendar year. The report begins by summarizing the weather...

  15. Lake Andes National Wildlife Refuge: Narrative report: January 1 through December 31, 1965

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Lake Andes NWR and WPA outlines Refuge accomplishments during the 1965 calendar year. The report begins by summarizing the weather...

  16. Phase 1 Watershed Assessment Final Report: Lake Andes Watershed, Charles Mix County, South Dakota.

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Lake Andes was included in the 1998 South Dakota 303(d) list as an impairment-related Total Maximum Daily Load waterbody. In 1922 Congress passed a bill that...

  17. Record Solar UV Irradiance in the Tropical Andes

    Directory of Open Access Journals (Sweden)

    DonatP.Häder

    2014-07-01

    Full Text Available High elevation, thin ozone layer, and clear sky produce intense ultraviolet (UV radiation in the tropical Andes. Recent models suggest that tropical stratospheric ozone will slightly decrease in the coming decades, potentially resulting in more UV anomalies. Data collected between 4,300-5,916 m above sea level (asl in Bolivia show how this trend could dramatically impact surface solar irradiance. During 61 days, two Eldonet dosimeters recorded extreme UV-B irradiance equivalent to a UV index (UVI of 43.3, which is the highest ground value ever reported. If they become more common, events of this magnitude may have societal and ecological implications, which make understanding the process leading to their generation critical. Our data show that this event and other major UV spikes were consistent with rising UV-B/UV-A ratios in the days to hours preceding the spikes, trajectories of negative ozone anomalies (NOAs, and radiative transfer modeling.

  18. 7 CFR 319.56-38 - Citrus from Chile.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 5 2010-01-01 2010-01-01 false Citrus from Chile. 319.56-38 Section 319.56-38... from Chile. Clementines (Citrus reticulata Blanco var. Clementine), mandarins (Citrus reticulata Blanco), and tangerines (Citrus reticulata Blanco) may be imported into the United States from Chile,...

  19. Validation of TRMM multi-satellite precipitation analysis (TMPA) products in the Peruvian Andes

    Science.gov (United States)

    Mantas, V. M.; Liu, Z.; Caro, C.; Pereira, A. J. S. C.

    2015-09-01

    The relevance of accurate and timely rainfall estimates cannot be overstated. The rainfall gauge network is still insufficient across significant areas worldwide. Rainfall estimates from spaceborne sensors present an opportunity to supplement the existing network and enable the development of critical, near real time applications. However, the societal benefits of such systems can only be realized if the estimates are properly validated and the performance of existing products accurately described. In this study, two products generated by the Tropical Rainfall Measuring Mission (TRMM) Multi-satellite Precipitation Analysis (TMPA) are validated for the Peruvian Andes. This is a region of complex topography that poses significant challenges to the retrieval of rainfall values from space. The TMPA products, both research grade (3B42V7) and near real time (3B42RT), are compared against in situ data. Different observation lengths are studied and the results are analyzed in light of geographic, topographic and climatic constraints. The Time Series of the science grade product were also studied under Dynamic Time Warping and Hierarchical Clustering to streamline inter-tile comparisons. The TMPA products show a good agreement with the gauge values, especially for more prolonged observation periods (over 8 days). The validation results display a strong regional dependence as a consequence of differences in the climate and topography. This region-specific performance calls for additional, detailed case studies and localized validation efforts. Overall the TMPA was found to perform adequately and provide quality information for a number of applications requiring timely estimates in convenient formats.

  20. Stable isotope evidence for multiple pulses of rapid surface uplift in the Central Andes, Bolivia

    OpenAIRE

    Leier, Andrew; McQuarrie, Nadine; Garzione, Carmala; Eiler, John

    2013-01-01

    Paleoelevation histories from mountain belts like the Central Andes of Bolivia provide important constraints on the timing and geodynamic mechanisms associated with surface uplift. We present new oxygen and carbon isotope data (δ^(18)O, δ^(13)C, and Δ_(47)) from Oligocene–Miocene strata exposed in the Eastern Cordillera of the Bolivian Central Andes in order to reconstruct both the deformation and paleoelevation history of the region prior to late Miocene time. Paleosol carbonate in strata >2...

  1. An elusive new species of Marsupial Frog (Anura: Hemiphractidae: Gastrotheca from the Andes of northern Peru

    Directory of Open Access Journals (Sweden)

    William E. Duellman

    2013-06-01

    Full Text Available A new species of marsupial frog, genus Gastrotheca, is described from high-elevation grasslands in the Andes in Región Amazonas in northernPeru, where even calling males are well hidden in deep moss. The new species is distinguished from all congeners by its unique color pattern that includes a narrow, blackbordered, yellow middorsal stripe. The species apparently belongs to the Gastrotheca plumbea Group, which ranges in the Andes from northern Colombia to northern Peru.

  2. Late Pleistocene deglaciation histories in the central Mérida Andes (Venezuela)

    OpenAIRE

    Angel Ceballos, Isandra Fortuna

    2016-01-01

    The central Mérida Andes (Venezuela) landscape is characterized by the presence of well-preserved glacial landforms located between 2400 and 4978 m a.s.l. Geomorphological studies of these glacial landforms significantly contribute to the Venezuelan Andes glaciations reconstructions. However, Last Glaciation (locally called Mérida Glaciation) was poorly reconstructed because of limited chronological data. This dissertation attempts to contribute to the Last Glaciation reconstruction and paleo...

  3. Utilizing NASA Earth Observations to Model Volcanic Hazard Risk Levels in Areas Surrounding the Copahue Volcano in the Andes Mountains

    Science.gov (United States)

    Keith, A. M.; Weigel, A. M.; Rivas, J.

    2014-12-01

    Copahue is a stratovolcano located along the rim of the Caviahue Caldera near the Chile-Argentina border in the Andes Mountain Range. There are several small towns located in proximity of the volcano with the two largest being Banos Copahue and Caviahue. During its eruptive history, it has produced numerous lava flows, pyroclastic flows, ash deposits, and lahars. This isolated region has steep topography and little vegetation, rendering it poorly monitored. The need to model volcanic hazard risk has been reinforced by recent volcanic activity that intermittently released several ash plumes from December 2012 through May 2013. Exposure to volcanic ash is currently the main threat for the surrounding populations as the volcano becomes more active. The goal of this project was to study Copahue and determine areas that have the highest potential of being affected in the event of an eruption. Remote sensing techniques were used to examine and identify volcanic activity and areas vulnerable to experiencing volcanic hazards including volcanic ash, SO2 gas, lava flow, pyroclastic density currents and lahars. Landsat 7 Enhanced Thematic Mapper Plus (ETM+), Landsat 8 Operational Land Imager (OLI), EO-1 Advanced Land Imager (ALI), Terra Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), Shuttle Radar Topography Mission (SRTM), ISS ISERV Pathfinder, and Aura Ozone Monitoring Instrument (OMI) products were used to analyze volcanic hazards. These datasets were used to create a historic lava flow map of the Copahue volcano by identifying historic lava flows, tephra, and lahars both visually and spectrally. Additionally, a volcanic risk and hazard map for the surrounding area was created by modeling the possible extent of ash fallout, lahars, lava flow, and pyroclastic density currents (PDC) for future eruptions. These model results were then used to identify areas that should be prioritized for disaster relief and evacuation orders.

  4. Fruit production in Chile: bright past, uncertain future

    Directory of Open Access Journals (Sweden)

    Jorge B. Retamales

    2011-10-01

    Full Text Available In 2007 (the last agricultural census, Chile had 308, 445 ha of fruit orchards: an increase of almost 32% from the previous census (1997. The most important species were table grapes (20%, avocados (13% and apples (12%. Some 22% of the fruit crops growing area corresponded to juvenile orchards; within the species with higher proportion of juvenile orchards were prunes (42% and blueberries (56%. Most orchards are located between latitude 27º18` S (Copiapó and 40º36´S (Puerto Varas. The industry is driven by the export component which accounts for more than 50% of the fruits produced. In the crop season 2009-2010, approximately 254 million boxes (around 2.5 million tons were exported, representing over US$ 3.5 million. Processed and fresh fruits represented 8.2 and 26.7% of the total forest and agricultural Chilean exports in 2008, respectively. The main markets for this fruits were USA/Canada (42% and Europe (32%. The fruit grower receives, on average, 12-16% of the total price of the fruit in its final destination. Each year the fruit industry employs 450.000 people directly, of which 1/3 are permanent. Even though the fruit industry employs the highest proportion of the agricultural labor and the growing area has increased in the last 20 years, the proportion of agricultural employment has decreased from 19.5% in 1989 to 10.8% in 2008. It might also be noted that Chile invests only 0.7% of the GDP in research. In the last 40 years, the fruit industry has been a motor for the Chilean economic development, but the lower rates of currency exchange, the rising costs of energy (oil, electricity, and the increasing scarcity of hand labor have drastically reduced the profitability and are putting at risk the viability of a large proportion of the fruit orchards in Chile. It is estimated that this season around 65% of the orchards will have a negative economic balance in their operations. Higher investment in research, improvements in fruit quality

  5. Presencia de los géneros invasores Mus y Rattus en áreas naturales de Chile: un riesgo ambiental y epidemiológico Presence of the invasive genera Mus and Rattus in natural areas in Chile: an environmental and epidemiological risk

    Directory of Open Access Journals (Sweden)

    GABRIEL LOBOS

    2005-03-01

    Full Text Available Realizamos un estudio que incluyó muestreos y prospecciones en un gradiente latitudinal en Chile continental para determinar la presencia y ausencia de roedores murinos introducidos, particularmente Mus musculus, Rattus rattus y R. norvegicus en áreas naturales o silvestres a lo largo de Chile. Además se analizó el riesgo epidemiológico que representan estas especies en el marco de un estudio sobre el virus Hanta. Los resultados mostraron que M. musculus rara vez es recolectado en áreas naturales. Sin embargo, las dos especies de Rattus han invadido ampliamente la región mediterránea chilena. Las regiones desérticas, los ambientes de alturas y las regiones australes, serían biótopos restringidos para estos invasores. Desde una perspectiva epidemiológica, la presencia del virus Hanta (variedades Andes y Seoul en Rattus es un elemento que demuestra que las especies invasoras además de generar impactos ecológicos, pueden ocasionar problemas económicos y de salud pública. La fragilidad de los ecosistemas mediterráneos determina que la presencia de especies exóticas constituya un elemento de alto riesgo para la conservación del patrimonio natural del país. Probablemente, la conservación de áreas naturales constituye la mejor herramienta para enfrentar a estas especies exóticasWe conducted a latitudinal study in natural areas of continental Chile to evaluate the occurrence of the introduced murine rodents Mus musculus, Rattus rattus and R. norvegicus. Furthermore, we evaluated the epidemiological risk of these species as part of an ongoing study on Hantavirus. The results allowed us to conclude that M. musculus occurs rarely in natural environments. However, the two species of Rattus have widely invaded the mediterranean region of Chile. Desert, altitudinal and high latitude regions seem to be restricted areas for these invasive rodents. From an epidemiological perspective, the occurrence of Hantavirus in Rattus (Andes and Seoul

  6. [Diabetic renal disease: the World Kidney Day in Chile].

    Science.gov (United States)

    Ardiles, Leopoldo; Mezzano, Sergio

    2010-04-01

    The third version of the World Kidney Day will be held on May 13, 2010 in Chile and will be focused in diabetic renal damage, the main cause of chronic kidney disease (CKD). Currently, we are living a pandemic of CKD, a progressive and irreversible condition with high social and economic impact. In Chile, we have 857 patients per million inhabitants in hemodialysis and 35% are secondary to diabetes. Our general prevalence of diabetes is 4.2%, rising to 15% in people aged more than 64 years. With a 34% prevalence of hypertension, an aging population, high prevalence of obesity, and a sedentary lifestyle, there is an estimation of a rise in 85% of the prevalence of diabetes in South-America, for the next decades. The steps to be taken are clear: campaigns should be aimed at (1) prevention of type 2 diabetes; (2) screening for early diabetic kidney disease; (3) increasing patient awareness of kidney disease; (4) using medications of proven strategy and finally (5) research on new therapies. These concepts must be included in community and professional education to reduce the effects of this pandemic. PMID:20668785

  7. Income Inequality in Chile: 1990-2006

    OpenAIRE

    Alain Hourton

    2012-01-01

    The entrance of Chile to the Organization for the Economic Cooperation and Development, as the first South American country and second after Mexico in Latin America, sets a landmark in the development path that since the beginning of the 1990s decade has seemed to lead this country to a privileged position in the region. Given the reforms taken by the military regime in the 1980s, Chile is one of the most market-oriented countries in Latin America, with Free Trade Agreements and Economical Pa...

  8. Orographic effects related to deep convection events over the Andes region

    Science.gov (United States)

    Hierro, R.; Pessano, H.; Llamedo, P.; de la Torre, A.; Alexander, P.; Odiard, A.

    2013-02-01

    In this work, we analyze a set of 39 storms which took place between 2006 and 2011 over the South of Mendoza, Argentina. This is a semiarid region situated at mid-latitudes (roughly between 32S and 36S) at the east of the highest Andes tops which constitutes a natural laboratory where diverse sources of gravity waves usually take place. We consider a cultivated subregion near San Rafael district, where every summer a systematic generation of deep convection events is registered. We propose that the lift mechanism required to raise a parcel to its level of free convection is partially supplied by mountain waves (MWs). From Weather Research and Forecasting (WRF) mesoscale model simulations and radar network data, we calculate the evolution of convective available potential energy and convective inhibition indices during the development of each storm. Global Final Analysis is used to construct initial and boundary conditions. Convective inhibition indices are compared with the vertical kinetic energy capable of being supplied by the MWs, in order to provide a rough estimation of this possible triggering mechanism. Vertical velocity is chosen as an appropriate dynamical variable to evidence the presence of MWs in the vicinity of each detected first radar echo. After establishing a criterion based on a previous work to represent MWs, the 39 storms are split into two subsets: with and without the presence of MWs. 12 cases with considerable MWs amplitude are retained and considered. Radar data differences between the two samples are analyzed and the simulated MWs are characterized.

  9. Analysis and projections of physics in Chile

    International Nuclear Information System (INIS)

    In the present work, an assessment of the Physics research capacity in Chile is presented. For this, the period between 2000 and June 2005 has been studied. In this period almost 200 physicists have contributed to scientific production in terms of ISI publications. Amongst these 200, ∼160 correspond to theoretical physicists and only ∼40 to experimental physicists; ∼178 are men and only ∼22 are women. A more detailed analysis shows that ∼160 physicists have at least one appearance in ISI publications per year considering the last 3 years. Ten years ago, a similar criteria (at least one appearance per year in ISI articles, considering mobile three-year periods), the number of active physicists in the Chilean community was estimated at 70. Therefore, the Chilean active physicists' community has doubled in 10 years. There exist 20 centres in which scientific research is developed: 18 university centres, a government institute and a private institute. As regards scientific productivity, both as related to disciplines or research areas, and well as in relation to research centres, it is found that, generally, scientific production, in a particular area in Physics or in a research centre, is directly related to the number of corresponding researchers; that is to say, the percentage of the national productivity in an area or research centre corresponds to its share in the total number of physicists in the country. A geographical analysis shows that 50% of the productivity corresponds to Santiago and 50% to the rest of the country. The impact of the different funds for research is assessed, also: FONDECYT, Presidential Chairs and large projects and centres of excellence. According to Physics researchers opinion, Fondo Nacional de Ciencia y TecnologIa (FONDECYT, National Fund fro Science and Technology) has become the best instrument to support researchi activities in Chile. However, the amount of projects awarded has practically not been increased, which is

  10. Phylogenetic relationships between telmatobiinids (Anura, Ceratophryidae, Telmatobiinae) of central Andes based on morphology of larval and adult stages

    OpenAIRE

    César Aguilar; Niels Valencia

    2011-01-01

    Batrachophrynus and Telmatobius are the two genus of Telmatobiinae from the central Andes. Both genera have species with adaptations for life at high altitude in the Andes, with aquatic or semi-aquatic habits in creeks, lagoons and lakes. The objective of this study is to evaluate the phylogenetic relationships between Batrachophrynus and 13 species of Telmatobius from the central Andes using larval and adult morphology including diagnostic characters for Batrachophrynus and Telmatobius, and ...

  11. Oral health in prehistoric San Pedro de Atacama oases, Northern Chile.

    Science.gov (United States)

    Oliveira, R E; Neves, W A

    2015-12-01

    After almost 2000 years of local development, including limited trading with neighboring ethnic groups, the societies that occupied the oases of San Pedro de Atacama, Northern Chile, became part of the trade web of the Tiwanaku empire, between 500 and 1000 CE. Archaeological evidence tends to support the idea that the period under the influence of the altiplano (high plane) empire was very affluent. Here we investigate the possibility that this affluence had a positive impact on the health status of the Atacameneans, using the oral health as an indirect indicator of quality of life. Dental decay, dental abscess, dental wear, linear enamel hypoplasia, periodontal disease and dental calculus were analyzed on 371 skeletons from 12 sites from San Pedro de Atacama oases. We believe that if, indeed, there were better biological conditions during the altiplano influence, this could have been caused by the access to a more diversified food intake promoted by the intensification of the trading network established by Tiwanaku in the central-south Andes, of which San Pedro de Atacama became an important node. PMID:26253130

  12. Assessing giant tsunamigenic subduction earthquakes in the Northern Chile Seismic Gap during the last two millennia

    Science.gov (United States)

    Vargas Easton, G.; Ruiz, S.; Leyton, F.; Abrahami, R.; Le Roux, J.; Pantoja, S.; Lange, C.; Contreras Reyes, E.; Campos, J. A.

    2014-12-01

    Marine sedimentary records off Northern Chile provide a new view about the occurrence of large subduction earthquakes along the hyperarid convergent margin of the Central Andes. From high resolution geochronology and sedimentology of laminated series accumulated on narrow shelf, we observed that anomalous structures such as slumps and discontinuities overlaid by turbidite deposits record the last giant Mw~8.8 earthquake and tsunami occurred on 1877 in the region. Once compared with the reanalysis of historical chronicles and seismological data, we suggest that only large magnitude events produce ground accelerations generating slumping or discontinuities. The analysis of long (ca. 5.5 m) sediment cores together with high resolution seismic subbottom profile data allow us to infer the occurrence of several giant earthquakes in the last ca. 1600 years, with a mean recurrence in the order of 400 years. Under this scope, the Mw8.1 occurred this year off Pisagua-Iquique region, as other previous historic events (Mw7.7, Tocopilla, 2007; Mw7.6, Iquique, 1933), seem to be moderate earthquakes into a larger seismic cycle.

  13. New Archaeological Evidence for an Early Human Presence at Monte Verde, Chile

    Science.gov (United States)

    Dillehay, Tom D.; Ocampo, Carlos; Saavedra, José; Sawakuchi, Andre Oliveira; Vega, Rodrigo M.; Pino, Mario; Collins, Michael B.; Scott Cummings, Linda; Arregui, Iván; Villagran, Ximena S.; Hartmann, Gelvam A.; Mella, Mauricio; González, Andrea; Dix, George

    2015-01-01

    Questions surrounding the chronology, place, and character of the initial human colonization of the Americas are a long-standing focus of debate. Interdisciplinary debate continues over the timing of entry, the rapidity and direction of dispersion, the variety of human responses to diverse habitats, the criteria for evaluating the validity of early sites, and the differences and similarities between colonization in North and South America. Despite recent advances in our understanding of these issues, archaeology still faces challenges in defining interdisciplinary research problems, assessing the reliability of the data, and applying new interpretative models. As the debates and challenges continue, new studies take place and previous research reexamined. Here we discuss recent exploratory excavation at and interdisciplinary data from the Monte Verde area in Chile to further our understanding of the first peopling of the Americas. New evidence of stone artifacts, faunal remains, and burned areas suggests discrete horizons of ephemeral human activity in a sandur plain setting radiocarbon and luminescence dated between at least ~18,500 and 14,500 cal BP. Based on multiple lines of evidence, including sedimentary proxies and artifact analysis, we present the probable anthropogenic origins and wider implications of this evidence. In a non-glacial cold climate environment of the south-central Andes, which is challenging for human occupation and for the preservation of hunter-gatherer sites, these horizons provide insight into an earlier context of late Pleistocene human behavior in northern Patagonia. PMID:26580202

  14. Observations of Comets and Eclipses in the Andes

    Science.gov (United States)

    Ziółkowski, Mariusz

    There is no doubt that the Incas possessed a system for observing and interpreting unusual astronomical phenomena, such as eclipses or comets. References to it, however, are scarce, often of anecdotal nature and are not collected into any coherent "Inca observation catalog". The best documented of such events is the "Ataw Wallpa's comet", seen in Cajamarca in July of 1533 and the solar eclipse, that in 1543, prevented conquistador Lucas Martínez from discovering the rich silver mines in northern Chile. Archived descriptions of the Andean population's reaction to these phenomena indicate that they were treated as extremely important omens, that should not, under any circumstances, be ignored.

  15. Hallazgo de Ehrlichia canis en Chile, informe preliminar Ehrlichia canis in Chile; preliminary report

    Directory of Open Access Journals (Sweden)

    J. LÓPEZ

    1999-01-01

    Full Text Available Se describe el primer caso de Ehrlichiosis canina detectado en Chile, causado por la rickettsia Ehrlichia canis y transmitida por el vector Rhipicephalus sanguineus. El diagnóstico clínico fue confirmado en Alemania por Inmunofluorescencia Indirecta (IFATThe first case of canine ehrlichiosis detected in Chile is described. It is caused by the rickettsia Ehrlichia canis and carried by the vektor Rhipicephalus sanguineus. The clinical diagnosis was confirmed in Germany using the Immunofluorescent Antibody Test (IFA

  16. Museos de Santiago de Chile. Directorio

    OpenAIRE

    Carrillo, Andrea; Funes, Catherine; Heredia, Constanza; Herrera, Daniela; Suárez, Víctor

    2012-01-01

    Directory of the museums in Santiago of Chile categorized by subject, such as Art, Archaeology, Historic house, Science and technology, Natural science and Natural history, Specialized, Ethnography and Anthropology, History, Site museum and Other. It comprehends basic information about name, creation date, collections, services, contact info, social network accounts, website and entrance fee of the museums.

  17. Republic of Chile : Country Procurement Assessment Report

    OpenAIRE

    World Bank

    2004-01-01

    Chile's public procurement system is considered generally free of corruption, supported by probity of the civil servants, decentralization, and good budgetary and control systems. However, it is affected by deficiencies that the government recognizes, and is taking action to overcome, particularly with respect to procurement of goods and services. There is no unified comprehensive, and pub...

  18. DEZVOLTAREA CONTEMPORANĂ A TURISMULUI DIN CHILE

    Directory of Open Access Journals (Sweden)

    Maria-Mihaela Győri

    2011-01-01

    Full Text Available The contemporary development of the Chilean Tourism sector is analyzed mainly on thebasis of data supplied by the National Service of Tourism in Chile. Figures on inboundtourism, domestic tourism, lodging, employment, receipts, as well as the existing structurewithin the sector, were taken into consideration for the investigated period of 1999-2006.

  19. [Notes about other epidemics in Colonial Chile].

    Science.gov (United States)

    Laval, Enrique

    2015-10-01

    In chronicles or in the historiography of the Colony in Chile there are few references about epidemics different to smallpox; like typhus, typhoid fever, dysentery, etc. Almost all, fast spreading in the country and some with high lethality, which led to overflowing the capacity of hospitals in the Chilean colonial period. PMID:26633117

  20. A Decade of Environment Management in Chile

    OpenAIRE

    Ruthenberg, Ina-Marlene

    2001-01-01

    This publication presents an evaluation of the Environmental Institutions Development Project in Chile, selected by Bank management to be part of an intensive learning process in final project evaluation, given its contributing factor to the Bank's knowledge base on environmental institutional development projects. The first part of the publication focuses on the project as catalyst for cu...

  1. Nuclear public information activities in Chile

    International Nuclear Information System (INIS)

    Nuclear plans and developing programs in developing and developed countries are facing-in a higher or lower degree- opposition from public opinion. The objectives and contents of the public education program on nuclear energy in Chile are dealt with in this paper

  2. Tectonic control on denudation rates in the central Bolivian Andes

    Science.gov (United States)

    Zeilinger, Gerold; Kober, Florian; Hippe, Kristina; Lendzioch, Theodora; Grischott, Reto; Pillco Zolá, Ramiro; Christl, Markus

    2013-04-01

    Effects of a positive feedback loop between erosion and tectonics have been shown by analogue and numerical models and have been inferred from field observations at the scale of mountain ranges. We present new data from the Bolivian Andes supporting these observations, although common geomorphic parameters do not indicate a simple correlation. The upper Rio Grande segment, located between Cochabamba, Santa Cruz and Sucre, drains a major catchment in the central Bolivian Cordillera, from the Eastern Cordillera (EC) in the W, through the Interandean Zone (IAZ) and the Subandes (SA) in the E. The catchment covers an area of 58939 km² with an altitude range from 400 to 5150 m above sea level. Geologically, the Bolivian Andes comprise (from W to E) the Altiplano, the EC, the IAZ and the SA fold and thrust belts. The Altiplano represents an almost perfectly closed basin with distinct barriers defined by the Western Cordillera and Eastern Cordillera. The Rio Grande does not reach the Altiplano (unlike Rio La Paz and Rio Consata) but has its western drainage divide along the high peaks of the EC that experienced a period of intense shortening between Late Oligocene and Miocene. Near Cochabamba, the EC comprises metasedimentary siliciclastic rocks of Ordovician age. These rocks are overlain by Cretaceous to Paleocene and / or Neogene sediments with an angular unconformity. The IAZ and SA form an east-vergent fold and thrust belt and comprise Paleozoic and Mesozoic units. Farther east, the structures of the SA progressively include Neogene foreland strata of the Chaco foreland basin. The Chaco basin rests on the Brazilian shield east of the Subandean Belt and forms the modern foreland basin, where the lower Rio Grande catchment is sited. We obtained 58 cosmogenic 10Be catchment wide denudation rates for the Rio Grande catchments upstream of Abapó. They range from 7 mm/kyr to 1550 mm/kyr thus integrating at maximum over the last 10.000 years, with a mean of 262 mm/kyr. In

  3. Sistema de salud de Chile The health system of Chile

    Directory of Open Access Journals (Sweden)

    Víctor Becerril-Montekio

    2011-01-01

    Full Text Available En este trabajo se describe el sistema de salud de Chile, incluyendo su estructura, financiamiento, beneficiarios y recursos físicos, materiales y humanos de los que dispone. Este sistema está compuesto por dos sectores, público y privado. El sector público está formado por todos los organismos que constituyen el Sistema Nacional de Servicios de Salud y cubre aproximadamente a 70% de la población, incluyendo a los pobres del campo y las ciudades, la clase media baja y los jubilados, así como los profesionales y técnicos. El sector privado cubre aproximadamente a 17.5% de la población perteneciente a los grupos sociales de mayores ingresos. Un pequeño sector de la población, perteneciente a la clase alta, realiza pagos directos de bolsillo a proveedores privados de servicios de atención a la salud. Alrededor de 10% de la población está cubierta por otras agencias públicas, fundamentalmente los Servicios de Salud de las Fuerzas Armadas. Recientemente el sistema se reformó creando el Régimen General de Garantías en Salud, que establece un Sistema Universal con Garantías Explícitas que se tradujo, en 2005, en el Plan de Acceso Universal con Garantías Explícitas (AUGE, que garantiza el acceso oportuno a servicios de calidad para 56 problemas de salud, incluyendo cáncer en niños, cáncer de mama, trastornos isquémicos del corazón, VIH/SIDA y diabetes.This paper describes the Chilean health system, including its structure, financing, beneficiaries, and its physical, material and human resources. This system has two sectors, public and private. The public sector comprises all the organisms that constitute the National System of Health Services, which covers 70% of the population, including the rural and urban poor, the low middle-class, the retired, and the self-employed professionals and technicians.The private sector covers 17.5% of the population, mostly the upper middle-class and the high-income population. A small

  4. Vulnerabilidad, resistividad en el campesinado rural de los Andes tropicales

    Directory of Open Access Journals (Sweden)

    Christoph Stadel

    2009-09-01

    Full Text Available Mientras que la colonización agrícola y humana tiene milenios de tradiciones culturales en los Andes tropicales, la agricultura y la superviviencia rural siempre representaban ‘sistemas abiertos’ adaptandose a una gran diversidad de condiciones medioambientales, políticas, culturales, sociales y económicas fluctuando con- tinuamente. Sin embargo, el patrimonio cultural tan variado y rico de los campesinos andinos con sus experiencias y conocimientos en sobrevivir en condiciones locales difíciles y sumamente vulnerables en muchos casos les ayudó a llegar a formas variadas de resistividad y resistencia frente a los estímulos y el estrés internos y externos. Además y dadas las condiciones medio ambientales tan diversas de las regiones andinas con su gran variedad de zonas altitudinales, nichos agrícolas y mosaicos culturales, se ha formado un paisaje rural muy complejo y variado. En este estudio se reconocen y se apoyan las identidades locales y regionales de las formas del uso de las tierras rurales y de las actividades agrícolas, además se examinan los impactos de las influencias supra-regionales y globales que determinan las condiciones climáticas, políticas, económicas y socio-culturales. De esta manera, una alta variabilidad y una baja predictabilidad de las condiciones andinas medioambientales y del desarrollo socio-económico forman los argumentos básicos en este estudio. Se rechaza la validez de un modelo universal del uso de las tierras agrícolas en los Andes así como una exposición inevitable de la agricultura montañesa frente a los riesgos de las fuerzas y los actores globales. Contrariamente, en el artículo se propone toda una serie de modelos locales y regionales para el uso de las tierras rurales que sean flexibles en relación al espacio y al tiempo tomando en cuenta las condiciones locales persistentes así como las nuevas influencias externas. Como resultado de estas consideraciones parece imprescindible

  5. Las guerras de independencia en los andes meridionales

    Directory of Open Access Journals (Sweden)

    Raquel Gil Montero

    2006-12-01

    Full Text Available Este trabajo analiza la composición de las milicias regionales que lucharon en la frontera bélica de los Andes Meridionales entre 1810 y 1825. Al interior de las tropas se mantuvo la jererquización y el corporativismo, características propias de la sociedad. Sin embargo, la convivencia y los rigores de la guerra generaron una suerte de "fondo común" con recursos de los grupos socio-étnicos. Entre estos recursos destacamos: la adopción de una organización para la comida basada en el abastecimiento realizado por las mujeres de los soldados; la aceptación de "licencias compulsivas"; o el nombramiento de líderes militares que no eran "bien nacidos". Además se aceptaban prácticas de matar propias de cada grupo y se los distinguía por las armas utilizadas. Estas costumbres compartidas no fueron iguales en todo espacio o tiempo pues dependieron de los elementos originales que se fundieron en la palestra y del contexto que les dio forma.This article analyses the composition of regional militias that participated in the frontier war fought in Southern Andes (1810-1825. It focuses on the relations militiamen established among themselves in a war context. It could be observed that hierarchical and corporative behavior, aspect found in society, was maintained within the troops. However, the act of living together and the severity of war resulted in a kind of pool of different practices belonging to each social-ethnic group. Among these shared practices we highlight: the way officers accepted the food preparation done by the soldiers' women, "compulsive leaves", and the designation of militia leaders who were not patrician. Moreover each group's killing practices were accepted and their weapons distinguished them. But shared practices were not constant through space and time since they depended upon original elements militiamen brought with them to the battlefield and on the context shaping them.

  6. Top income shares, business profits, and effective tax rates in contemporary Chile

    OpenAIRE

    Fairfield, Tasha; Jorratt, Michel

    2014-01-01

    This paper contributes to the burgeoning research on inequality and top incomes around the globe by presenting the first available estimates of top income shares and effective income tax rates in contemporary Chile based on analysis of anonymous income tax return microdata. We pay special attention to business income, which dominates at the top of the distribution. Our analysis includes not only distributed profits, but also the large proportion of accrued profits retained by firms. Our most ...

  7. 2D Anisotropic Wavelet Entropy with an Application to Earthquakes in Chile

    Directory of Open Access Journals (Sweden)

    Orietta Nicolis

    2015-06-01

    Full Text Available We propose a wavelet-based approach to measure the Shannon entropy in the context of spatial point patterns. The method uses the fully anisotropic Morlet wavelet to estimate the energy distribution at different directions and scales. The spatial heterogeneity and complexity of spatial point patterns is then analyzed using the multiscale anisotropic wavelet entropy. The efficacy of the approach is shown through a simulation study. Finally, an application to the catalog of earthquake events in Chile is considered.

  8. The Relative Price of Nontraded Goods, Absorption, and Exchange Rate Policy in Chile, 1974-82

    OpenAIRE

    Guillermo R. Le Fort

    1988-01-01

    The empirical effects of exchange rate policy and changes in absorption on the relative price of nontraded goods in Chile are examined. Three alternative theories of relative-price determination in a developing economy are tested: purchasing power parity, sector-specific factors, and sticky wages. The estimation results, obtained using both classical and Bayesian methods, favor the sticky-wages theory. Thus, as long as public sector wages are not fully indexed, a devaluation will have a lasti...

  9. The Impact of College Peers on Academic Performance: Evidence from a Natural Experiment in Chile

    OpenAIRE

    Díez-Amigo, Sandro

    2014-01-01

    First year students at the Pontificia Universidad Católica de Chile, one of the leading Chilean universities, are randomly assigned to their first semester college class groups. This paper takes advantage of this natural experiment in order to robustly estimate the impact of peer characteristics on undergraduate academic performance. The research hypothesis is that being assigned as a freshman to a group with more or less students from a same school, or from a given socioeconomic background, ...

  10. Fold and thrust belt structures and strike-slip faulting at the SE margin of the Salar de Atacama basin, Chilean Andes

    Science.gov (United States)

    Kuhn, Dirk

    2002-07-01

    A tectonic reinterpretation is reported for the southeastern margin of the Salar de Atacama basin of northern Chile. Detailed structural mapping revealed the presence of an east vergent thin-skinned fold and thrust belt affecting Oligocene-Miocene Paciencia Group rocks and the overlying Plio-Pleistocene volcanic rocks. Along-strike segmentation of the main fold implies local foreland influence on footwall ramp geometry leading to local thrust sheet rotation. To the east the adjacent western slope of the Western Cordillera displays two different structural domains, probably controlled by preexisting basement structures. The southern domain comprises two N-S oriented sigmoidal belts of linear arranged pressure ridges, indicating left-lateral transpression. In contrast, the northern domain is characterized by east vergent fold and thrust belt structures and reactivated NW-SE striking sinistral strike-slip faults, governing clockwise block rotations. An indenter-driven deformation model is proposed to explain sinistral transpression and clockwise block rotations around vertical axes. This variant of a small-block rotation mechanism is discussed in the context of oroclinal bending of the central Andes, emphasizing the significance of ancient structures in controlling rotations.

  11. Across the southern Andes on fin: glacial refugia, drainage reversals and a secondary contact zone revealed by the phylogeographical signal of Galaxias platei in Patagonia.

    Science.gov (United States)

    Zemlak, Tyler S; Habit, Evelyn M; Walde, Sandra J; Battini, Miguel A; Adams, Emily D M; Ruzzante, Daniel E

    2008-12-01

    We employed DNA sequence variation at two mitochondrial (control region, COI) regions from 212 individuals of Galaxias platei (Pisces, Galaxiidae) collected throughout Patagonia (25 lakes/rivers) to examine how Andean orogeny and the climatic cycles throughout the Quaternary affected the genetic diversity and phylogeography of this species. Phylogenetic analyses revealed four deep genealogical lineages which likely represent the initial division of G. platei into eastern and western lineages by Andean uplift, followed by further subdivision of each lineage into separate glacial refugia by repeated Pleistocene glacial cycles. West of the Andes, refugia were likely restricted to the northern region of Patagonia with small relicts in the south, whereas eastern refugia appear to have been much larger and widespread, consisting of separate northern and southern regions that collectively spanned most of Argentinean Patagonia. The retreat of glacial ice following the last glacial maximum allowed re-colonization of central Chile from nonlocal refugia from the north and east, representing a region of secondary contact between all four glacial lineages. Northwestern glacial relicts likely followed pro-glacial lakes into central Chilean Patagonia, whereas catastrophic changes in drainage direction (Atlantic --> Pacific) for several eastern palaeolakes were the likely avenues for invasions from the east. These mechanisms, combined with evidence for recent, rapid and widespread population growth could explain the extensive contemporary distribution of G. platei throughout Patagonia. PMID:19017262

  12. Horizontal wind and temperature in the lower thermosphere (80-140 km) measured by a Na Lidar at Andes Lidar Observatory

    Science.gov (United States)

    Liu, Alan Z.; Vargas, F.; Guo, Yafang; Swenson, Gary

    2016-07-01

    We report the first measurement of nighttime atmospheric temperature and horizontal wind profiles in the lower thermosphere up to 140 km with the Na lidar at Andes Lidar Observatory in Cerro Pachón, Chile (30.3S, 70.7W), when enhanced thermospheric Na was observed. Temperature and horizontal wind were derived up to 140 km using various resolutions, with the lowest resolution of about 2.7 hr and 15 km above 130 km. Thus the measurements span 60 km in vertical, more than double the traditional 25 km. On the night of 17 April 2015, the horizontal wind magnitude in the thermosphere exceeds 150 m/s, consistent with past rocket measurements. The meridional wind shows a clear transition from the diurnal-tide-dominant mesopause to the semidiurnal-tide-dominant lower thermosphere. A lidar with a 100 times the power-aperture product will be able to measure wind and temperature above 160 km and cover longer time span, providing key measurements for the study of atmosphere-space interactions in this region.

  13. Presencia del género Stegomastodon entre los restos fósiles de mastodontes de Chile (Gomphotheriidae, Pleistoceno superior

    Directory of Open Access Journals (Sweden)

    Alberdi, M. T.

    2005-04-01

    Full Text Available New Gomphotheriidae fossils encouraged the authors to study recently obtained them and review some others materials of this family that were classified in 2000 as Cuvieronius hyodon (Fischer. Together with new tusks remains, the recovery of the anterior portion of the cranial symphysis (alveolar zone of a skull from Taguatagua is remarkable. The morphology of the available tusks and the characteristics of the anterior part of the symphysis allow the assignment of these remains to Stegomastodon. The occurrence of this genus at the end of the Pleistocene in Chile is established. Fossils are compared with others remains from South America and probable dispersal routes through the Andes cordillera are discussed.Nuevos materiales fósiles de Gomphotheriidae obtenidos recientemente, estimularon a los autores a estudiarlos y a revisar algunos otros restos de esta familia, que habían sido asignados, el año 2000, a Cuvieronius hyodon (Fischer. Junto a nuevos restos de defensas, destaca la recuperación de la parte anterior de la sínfisis craneal (zona alveolar de un cráneo de Taguatagua. La morfología de las defensas disponibles y las características de la porción anterior de la sínfisis, permiten asignar estos materiales al género Stegomastodon, fundamentando así la presencia de este género en el Pleistoceno terminal de Chile. Se comparan con otros restos de América del Sur y se discuten las probables vías de migración de estos mamíferos a través de la cordillera de los Andes.

  14. Evaluation of TRMM Multi-satellite Precipitation Analysis (TMPA) performance in the Central Andes region and its dependency on spatial and temporal resolution

    Science.gov (United States)

    Scheel, M. L. M.; Rohrer, M.; Huggel, Ch.; Santos Villar, D.; Silvestre, E.; Huffman, G. J.

    2011-08-01

    Climate time series are of major importance for base line studies for climate change impact and adaptation projects. However, for instance, in mountain regions and in developing countries there exist significant gaps in ground based climate records in space and time. Specifically, in the Peruvian Andes spatially and temporally coherent precipitation information is a prerequisite for ongoing climate change adaptation projects in the fields of water resources, disasters and food security. The present work aims at evaluating the ability of Tropical Rainfall Measurement Mission (TRMM) Multi-satellite Precipitation Analysis (TMPA) to estimate precipitation rates at daily 0.25° × 0.25° scale in the Central Andes and the dependency of the estimate performance on changing spatial and temporal resolution. Comparison of the TMPA product with gauge measurements in the regions of Cuzco, Peru and La Paz, Bolivia were carried out and analysed statistically. Large biases are identified in both investigation areas in the estimation of daily precipitation amounts. The occurrence of strong precipitation events was well assessed, but their intensities were underestimated. TMPA estimates for La Paz show high false alarm ratio. The dependency of the TMPA estimate quality with changing resolution was analysed by comparisons of 1-, 7-, 15- and 30-day sums for Cuzco, Peru. The correlation of TMPA estimates with ground data increases strongly and almost linearly with temporal aggregation. The spatial aggregation to 0.5°, 0.75° and 1° grid box averaged precipitation and its comparison to gauge data of the same areas revealed no significant change in correlation coefficients and estimate performance. In order to profit from the TMPA combination product on a daily basis, a procedure to blend it with daily precipitation gauge measurements is proposed. Different sources of errors and uncertainties introduced by the sensors, sensor-specific algorithm aspects and the TMPA processing scheme

  15. Evaluation of TRMM Multi-satellite Precipitation Analysis (TMPA performance in the Central Andes region and its dependency on spatial and temporal resolution

    Directory of Open Access Journals (Sweden)

    M. L. M. Scheel

    2010-10-01

    Full Text Available Climate time series are of major importance for base line studies for climate change impact and adaptation projects. However, in mountain regions and in developing countries there exist significant gaps in ground based climate records in space and time. Specifically, in the Peruvian Andes spatially and temporally coherent precipitation information is a prerequisite for ongoing climate change adaptation projects in the fields of water resources, disasters and food security. The present work aims at evaluating the ability of Tropical Rainfall Measurement Mission (TRMM Multi-satellite Precipitation Analysis (TMPA to estimate precipitation rates at daily 0.25° × 0.25° scale in the Central Andes and the dependency of the estimate performance on changing spatial and temporal resolution. Comparison of the TMPA product with gauge measurements in the regions of Cuzco, Peru and La Paz, Bolivia were carried out and analysed statistically. Large biases are identified in both investigation areas in the estimation of daily precipitation amounts. The occurrence of strong precipitation events was well assessed, but their intensities were underestimated. TMPA estimates for La Paz show high false alarm ratio.

    The dependency of the TMPA estimate quality with changing resolution was analysed by comparisons of 1-, 7-, 15- and 30-day sums for Cuzco, Peru. The correlation of TMPA estimates with ground data increases strongly and almost linearly with temporal aggregation. The spatial aggregation to 0.5°, 0.75° and 1° grid box averaged precipitation and its comparison to gauge data of the same areas revealed no significant change in correlation coefficients and estimate performance.

    In order to profit from the TMPA combination product on a daily basis, a procedure to blend it with daily precipitation gauge measurements is proposed.

    Different sources of errors and uncertainties introduced by the sensors, sensor-specific algorithm aspects

  16. Evaluation of TRMM Multi-satellite Precipitation Analysis (TMPA performance in the Central Andes region and its dependency on spatial and temporal resolution

    Directory of Open Access Journals (Sweden)

    M. L. M. Scheel

    2011-08-01

    Full Text Available Climate time series are of major importance for base line studies for climate change impact and adaptation projects. However, for instance, in mountain regions and in developing countries there exist significant gaps in ground based climate records in space and time. Specifically, in the Peruvian Andes spatially and temporally coherent precipitation information is a prerequisite for ongoing climate change adaptation projects in the fields of water resources, disasters and food security. The present work aims at evaluating the ability of Tropical Rainfall Measurement Mission (TRMM Multi-satellite Precipitation Analysis (TMPA to estimate precipitation rates at daily 0.25° × 0.25° scale in the Central Andes and the dependency of the estimate performance on changing spatial and temporal resolution. Comparison of the TMPA product with gauge measurements in the regions of Cuzco, Peru and La Paz, Bolivia were carried out and analysed statistically. Large biases are identified in both investigation areas in the estimation of daily precipitation amounts. The occurrence of strong precipitation events was well assessed, but their intensities were underestimated. TMPA estimates for La Paz show high false alarm ratio.

    The dependency of the TMPA estimate quality with changing resolution was analysed by comparisons of 1-, 7-, 15- and 30-day sums for Cuzco, Peru. The correlation of TMPA estimates with ground data increases strongly and almost linearly with temporal aggregation. The spatial aggregation to 0.5°, 0.75° and 1° grid box averaged precipitation and its comparison to gauge data of the same areas revealed no significant change in correlation coefficients and estimate performance.

    In order to profit from the TMPA combination product on a daily basis, a procedure to blend it with daily precipitation gauge measurements is proposed.

    Different sources of errors and uncertainties introduced by the sensors, sensor

  17. Active Folding of the Tame Anticline, Eastern Foothills, Colombian Andes

    Science.gov (United States)

    Veloza-Fajardo, G.; Taylor, M. H.; Mora, A.; Stockli, D. F.

    2011-12-01

    We integrate neotectonic mapping and interpretation of seismic reflection profiles to evaluate the kinematics of folding and development of the Quaternary Tame anticline and Cusiana fault at 6.5 N Latitude in the eastern foothills of the Eastern Cordillera of Colombia. The Tame anticline is located approximately 660 km to the east of the Nazca-South America and 810 km to the south of the Caribbean-South America subduction zones plate boundaries in a retroarc foreland basin setting. The Tame anticline is an elongated, N15E trending structure, 14 km long N-S by 6 km wide E-W, that represents the most frontal active structure of the northern Colombian Andes. The Tame fold is related to the east-directed Cusiana fault that day lights to the south. Seismic reflection profiles indicate the Cusiana fault is a listric, west-dipping blind structure. The east flowing antecedent Macaguana creek has incised the Tame fold forming three prominent terrace levels, uplifted approximately 220, 150 and 100 meters, above current river levels. The surfaces were sampled for terrestrial cosmogenic nuclides using the depth profiling approach to account for inheritance. Surface exposure ages from the highest to lowest surfaces are 93.9, 50.8 and 32.4 kyrs at the 1σ level respectively, which were calculated using Monte Carlo methods. Trishear kinematic modeling was used to retrodeform the folding history and based on the surface abandonment ages, we will present shortening rates at millennial timescales.

  18. Linchamientos y conflicto político en Los Andes Lynchings and Political conflict in The Andes

    Directory of Open Access Journals (Sweden)

    Carlos M. Vilas

    2007-06-01

    Full Text Available En 2004, los alcaldes de dos municipalidades de la región aimara de los Andes fueron linchados en la aparente culminación de agudos conflictos políticos internos y entre las respectivas comunidades y el Estado central. En este artículo se discuten ambos casos con el fin de ilustrar las transformaciones experimentadas en años recientes en la organización y la dinámica interna de las comunidades andinas, y de la articulación conflictiva de la política local en los procesos e instituciones de más amplio alcance. Precariedad social e incapacidad o renuencia del Estado para responder con eficacia a demandas básicas de determinados grupos de población configuran enmarcamientos socioeconómicos e institucionales de los linchamientos. En contraste con enfoques que enfatizan en factores culturales tradicionales o en un supuesto nacionalismo indígena, en el artículo se destaca la gravitación de fenómenos y procesos político- institucionales recientes en la transformación cultural y política de las comunidades, en el modo en que éstas procesan sus conflictos internos y con el Estado central.In 2004, two municipalitys mayors form the aimara Andes of Peru and Bolivia were subjected to mass lynchings as a result of the apparent culmination of violent political confrontations. This paper deals with these events as dramatic illustrations of the transformations the Andean communities experienced during recent decades in their internal dynamics, as well as in the articulation of local politics to processes and institutions beyond the communal limits. Structural precariousness combined with the state's inability or reluctance to come to terms with social or political demands from relevant segments of the people in the communities set the socioeconomic and institutional stage for lynchings. In contrast with approaches relating these events to an alleged indigenous cultural identity, the analysis points to the impact of the communities' political

  19. Characteristics of Precipitation Features and Annual Rainfall during the TRMM Era in the Central Andes

    Science.gov (United States)

    Mohr, Karen I.; Slayback, Daniel; Yager, Karina

    2014-01-01

    The central Andes extends from 7 deg to 21 deg S, with its eastern boundary defined by elevation (1000m and greater) and its western boundary by the coastline. The authors used a combination of surface observations, reanalysis, and the University of Utah Tropical Rainfall Measuring Mission (TRMM) precipitation features (PF) database to understand the characteristics of convective systems and associated rainfall in the central Andes during the TRMM era, 1998-2012. Compared to other dry (West Africa), mountainous (Himalayas), and dynamically linked (Amazon) regions in the tropics, the central Andes PF population was distinct from these other regions, with small and weak PFs dominating its cumulative distribution functions and annual rainfall totals. No more than 10% of PFs in the central Andes met any of the thresholds used to identify and define deep convection (minimum IR cloud-top temperatures, minimum 85-GHz brightness temperature, maximum height of the 40-dBZ echo). For most of the PFs, available moisture was limited (less than 35mm) and instability low (less than 500 J kg(exp -1)). The central Andes represents a largely stable, dry to arid environment, limiting system development and organization. Hence, primarily short-duration events (less than 60 min) characterized by shallow convection and light to light-moderate rainfall rates (0.5-4.0 mm h(exp -1)) were found.

  20. Personajes fuera de lugar: antropomorfos tardíos en el arte rupestre del norte semiárido de Chile Images out of place: late period antropomorphous figures in the rock art of central Chile

    Directory of Open Access Journals (Sweden)

    Andrés Troncoso

    2011-07-01

    Full Text Available Los personajes con vestimenta son una de las representaciones rupestres más conocidas del noroeste argentino y el norte de Chile, y su presencia en ambas áreas es un indicador de la importante dinámica de interacción ocurrida durante el período Tardío entre ambos espacios. Una variedad de estos personajes son los antropomorfos con cuerpos de lados cóncavos (sensu Montt 2005, los que en ocasiones se representan asociados a escutiformes santamarianos. Si bien se ha planteado que su distribución meridional por la vertiente andina occidental no traspasa el área de San Pedro de Atacama (Montt 2005, en este trabajo presentamos tres diseños antropomorfos con cuerpo de lados cóncavos reconocidos en el arte rupestre del valle de Illapel (30° LS, Provincia del Choapa, Norte Semiárido de Chile. En particular, se establece un análisis formal de estos diseños y se los compara con aquellos reconocidos en zonas más septentrionales, para luego discutir su cronología y evaluar las implicancias de su presencia en espacios tan alejados a su área de distribución original, registro que se asocia, en la región, a la circulación de diseños establecida por el Tawantinsuyu.Anthropomorphous figures with clothing stand out among the most frequent representations in the rock art of Northwestern Argentina and Northern Chile. Their ubiquity in both areas has been considered as an indicator of the dynamics of interregional interaction during late prehistory. Antropomorphous with concave sides (sensu Montt 2005 are but one expression of these popular type of representations, and at least in some cases are associated with "shield-man" of the Santa María style. Even though it has been stated previously that for the western Cordillera de los Andes the southernmost dispersion of this type of anthropomorphous figure is the San Pedro de Atacama area (Montt 2005, in this paper we present three such figures recently recorded in the rock art of the Illapel valley

  1. Evidence of proterozoic crust under the coastal Cordillera of Central Chile: Grenville age xenocrystic zircons in cretaceous volcanic rocks

    International Nuclear Information System (INIS)

    In the central Andes, Proterozoic basement rocks outcrop in isolated areas from beneath a Mesozoic and Cenozoic cover in southern Peru, northernmost Chile, Bolivia, and in northwestern Argentina. Their role in Andean magmatism and metallogenesis is well documented. In the southern Central Andes, Proterozoic rocks are so far known to outcrop in Argentina, east of the continental divide. In the course of U-Pb dating of the bimodal volcanic and sub-volcanic host rocks for Mesozoic manto-type copper deposits, we have encountered xenocrystic zircon with Proterozoic and Paleozoic ages. In the Punta del Cobre Cu-Fe (Au) District (27o30' S / 70o15' W) 22 km south of Copiapo xenocrystic zircon in the Lower Cretaceous host dacite yields ca. 1 Ga ages. In the El Soldado Cu District, (32o38' S /71o04' W), 120 km northwest of Santiago, scarce and strongly resorbed zircon crystals in the Lower Cretaceous host rhyodacite yield ages of 0.5 to 1.3 Ga. The early Cretaceous bimodal volcanic and subvolcanic rocks, which consists of primitive calc-alkaline basalts and rhyodacites, display geochemical evidence of crustal contamination. Our results suggest that, during their formation and ascent, the felsic magmas picked up zircons in the Proterozoic and Paleozoic crystalline basement of the Coastal Cordillera. The presence of Proterozoic (Grenville age) basement underlying localities as close as 30 km from the Pacific coast has implications for the extent and age of the Chilenia Terrane and gives further credence to correlation models that juxtapose eastern North America (Laurentia) and southwestern South America (Gondwana) during the Late Proterozoic (au)

  2. Traditional use of the Andean flicker (Colaptes rupicola as a galactagogue in the Peruvian Andes

    Directory of Open Access Journals (Sweden)

    Froemming Steve

    2006-05-01

    Full Text Available Abstract This paper explores the use of the dried meat and feathers of the Andean Flicker (Colaptes rupicola to increase the milk supply of nursing women and domestic animals in the Andes. The treatment is of preColumbian origin, but continues to be used in some areas, including the village in the southern Peruvian highlands where I do ethnographic research. I explore the factors giving rise to and sustaining the practice, relate it to other galactagogues used in the Andes and to the use of birds in ethnomedical and ethnoveterinary treatments in general, and situate it within the general tendency in the Andes and elsewhere to replicate human relations in the treatment of valuable livestock. The bird's use as a galactagogue appears to be motivated by both metaphorical associations and its perceived efficacy, and conceptually blends human and animal healthcare domains.

  3. How efficient are pension fund managers in Chile? Quão eficientes são os administradores de fundos de pensão no Chile?

    Directory of Open Access Journals (Sweden)

    Armando Barrientos

    2005-08-01

    Full Text Available The paper measures and evaluates technical efficiency among pension fund managers in Chile. Recent pension reform has established pension fund management market in nine countries in Latin America. The new pension providers compete for affiliates on the basis of fees, rates of return, and quality of service, and are subject to extensive regulation. Applying data envelopment analysis to data from Chile 1982-1999, the paper examines issues of efficiency, competition, and regulation. The analysis concludes that pension fund managers operate below the estimated "efficiency frontier", and there is no evidence of a sustained upward trend in technical efficiency over time.Este artigo se propõe a avaliar e medir a eficiência técnica dos administradores de fundos de previdência privada no Chile. A recente reforma sofrida pela previdência deu lugar a um mercado de gestão de fundos de aposentadoria em nove países da América Latina. Esses novos gestores de fundos de pensão competem por investidores através do custo de suas tarifas, dos índices de rendimento oferecidos e da qualidade do serviço prestado, estando sujeitos a uma regulamentação rigorosa. Aplicando a análise por envoltória de dados (DEA aos dados obtidos para o Chile entre 1982 e 1999, examinamos aqui as questões de eficiência, competitividade e regulamentação. Nossa análise conclui que os administradores de fundos de previdência privada operam abaixo do nível de eficiência desejado, e não há previsão de que venha a ocorrer nenhuma melhora consistente na eficiência técnica desses fundos num futuro próximo.

  4. Conditioning of radium sources in Chile

    International Nuclear Information System (INIS)

    A process experimented in Chile to conditioning Ra-226 sources arising as waste from medical uses in Chile is described. The IAEA offered to participate in the Project for Conditioning Radium Sources in order to place all the radium sources in the country under an internationally accepted standard. These sources hare those that have been used in medical applications for many years. The CCHEN made its own modifications to the project's execution by using its own infrastructure and scientific and technical skill in this field. For this purpose, the CCHEN uses the human resources and facilities of the Radioactive Waste Management Unit (UGDR) and acquires materials that are commercially available in the country. IAEA assistance focused on quality assurance, so they supply all expensive items which the UGDR, cannot access, plus they certify the quality of the conditioned products. This assistance is achieved through the approval of procedures and methodologies based on those that are recommended

  5. Hemophilia in Chile, 1996-2006

    Directory of Open Access Journals (Sweden)

    Mario Donoso Scroppo

    2013-06-01

    Full Text Available This article describes the process that Chile underwent from 1996 to 2006, which is the dawn of a period of planned and systematic organization that begins to solve the severe health problems that afflict patients with hemophilia. The article reports a general overview of the situation of hemophilia in Chile in that period – up to 2006 - , including the lack of reliable data, treatment options, training of specialists on the topic and healthcare system responses. The article then goes on to describe in general terms the main aspects of Operation Access and the National Hemostasis and Thrombosis Program, the results of which will be described in a subsequent article of this series.

  6. Thermoluminescence properties of Chile Guajillo (paprika) Mexicano

    International Nuclear Information System (INIS)

    The thermoluminescence properties of the inorganic dust extracted from the Chile Guajillo (paprika) Mexicano, were studied in order to verify the possibility of using the TL technique to discriminate between irradiated and non irradiated peppers. The inorganic dust was found to consist of quartz 60%, albite (NaAlSi3O8) 30%, and ortose (KAlSi3O8) 10%. Its thermoluminescence dose response covers the wide dose range of 1Gy-10kGy, which was attributed mainly to feldspars. Its high sensitivity and its stability over 10 irradiation-readout cycles allow the application of a single grain-single aliquot regeneration dosimetry in Chile Guajillo (paprika). Evaluations based on trapping parameters show that thermal fading at room temperature for glow-peaks above 180 deg.. C, is not a problem in the dosimetry of paprika

  7. Reconstructing the annual mass balance of the Echaurren Norte glacier (Central Andes, 33.5° S) using local and regional hydroclimatic data

    Science.gov (United States)

    Masiokas, Mariano H.; Christie, Duncan A.; Le Quesne, Carlos; Pitte, Pierre; Ruiz, Lucas; Villalba, Ricardo; Luckman, Brian H.; Berthier, Etienne; Nussbaumer, Samuel U.; González-Reyes, Álvaro; McPhee, James; Barcaza, Gonzalo

    2016-04-01

    Despite the great number and variety of glaciers in southern South America, in situ glacier mass-balance records are extremely scarce and glacier-climate relationships are still poorly understood in this region. Here we use the longest (> 35 years) and most complete in situ mass-balance record, available for the Echaurren Norte glacier (ECH) in the Andes at ˜ 33.5° S, to develop a minimal glacier surface mass-balance model that relies on nearby monthly precipitation and air temperature data as forcing. This basic model is able to explain 78 % of the variance in the annual glacier mass-balance record over the 1978-2013 calibration period. An attribution assessment identified precipitation variability as the dominant forcing modulating annual mass balances at ECH, with temperature variations likely playing a secondary role. A regionally averaged series of mean annual streamflow records from both sides of the Andes between ˜ 30 and 37° S is then used to estimate, through simple linear regression, this glacier's annual mass-balance variations since 1909. The reconstruction model captures 68 % of the observed glacier mass-balance variability and shows three periods of sustained positive mass balances embedded in an overall negative trend over the past 105 years. The three periods of sustained positive mass balances (centered in the 1920s-1930s, in the 1980s and in the first decade of the 21st century) coincide with several documented glacier advances in this region. Similar trends observed in other shorter glacier mass-balance series suggest that the Echaurren Norte glacier reconstruction is representative of larger-scale conditions and could be useful for more detailed glaciological, hydrological and climatological assessments in this portion of the Andes.

  8. Coastal Upwelling off Chile: Ocean Productivity and Surface Sediments

    Science.gov (United States)

    Hebbeln, D.; Lamy, F.

    2002-12-01

    The coastal upwelling system of the Peru-Chile Current belongs to the most productive regions in the world oceans. In spite of this fact only very little is known about the sediment distribution in its southern part off the coast of Chile. To increase the knowledge about this region a multi-parameter study of the surface sediment distribution at over 100 sampling sites along the Chilean continental slope between 23°S and 45°S has been carried out. Detailed analyses of sedimentary data (TOC, carbonate, and biogenic opal contents, delta 15N) reveal a close relation to environmental conditions in the region. Coastal upwelling along the Chilean coast, centered around main upwelling centers such as off Antofagasta (23°S), off Lengua de Vaca (30°S), off Valparaiso (33°S), and off Concepci¢n (35-38°S), sustains the high productivity observed in satellite pigment data and in sediment data. However, the highest pigment concentrations are found south of 40°S where prevailing onshore winds of the Southern Westerlies generally prevent coastal upwelling. There, also highest estimated accumulation rates of organic carbon and biogenic opal at the sea floor are found. Thus, the general pattern of a southward increase of surface water productivity known from satellite data is closely reflected in the organic carbon, biogenic opal and ?15N data, although the observation of highest productivity south of the upwelling area is surprising. Probably, this high productivity in the south can be attributed to the advection of (macro-) nutrients by the Antarctic Circumpolar Current, supplying so-called high nutrient-low chlorophyll (HNLC) waters to the Chilean margin. Impinging on the Chilean margin these waters can take up micronutrients such as iron from the strong riverine input and from benthic exchange processes. The combination of macro- and micro-nutrients in this area most likely results in the high productivity of the area between 40°S and 45°S. From there these fertile

  9. Tectonic implications of a paleomagnetic study of the Sarmiento Ophiolitic Complex, southern Chile

    Science.gov (United States)

    Rapalini, A. E.; Calderón, M.; Singer, S.; Hervé, F.; Cordani, U.

    2008-06-01

    A paleomagnetic study was carried out on the Late Jurassic Sarmiento Ophiolitic Complex (SOC) exposed in the Magallanes fold and thrust belt in the southern Patagonian Andes (southern Chile). This complex, mainly consisting of a thick succession of pillow-lavas, sheeted dikes and gabbros, is a seafloor remnant of the Late Jurassic to Early Cretaceous Rocas Verdes basin that developed along the south-western margin of South America. Stepwise thermal and alternating field demagnetization permitted the isolation of a post-folding characteristic remanence, apparently carried by fine grain (SD?) magnetite, both in the pillow-lavas and dikes. The mean "in situ" direction for the SOC is Dec: 286.9°, Inc: - 58.5°, α95: 6.9°, N: 11 (sites). Rock magnetic properties, petrography and whole-rock K-Ar ages in the same rocks are interpreted as evidence of correlation between remanence acquisition and a greenschist facies metamorphic overprint that must have occurred during latest stages or after closure and tectonic inversion of the basin in the Late Cretaceous. The mean remanence direction is anomalous relative to the expected Late Cretaceous direction from stable South America. Particularly, a declination anomaly over 50° is suggestively similar to paleomagnetically interpreted counter clockwise rotations found in thrust slices of the Jurassic El Quemado Fm. located over 100 km north of the study area in Argentina. Nevertheless, a significant ccw rotation of the whole SOC is difficult to reconcile with geologic evidence and paleogeographic models that suggest a narrow back-arc basin sub-parallel to the continental margin. A rigid-body 30° westward tilting of the SOC block around a horizontal axis trending NNW, is considered a much simpler explanation, being consistent with geologic evidence. This may have occurred as a consequence of inverse reactivation of old normal faults, which limit both the SOC exposures and the Cordillera Sarmiento to the East. The age of tilting

  10. Evolution of Housing Prices in Chile

    OpenAIRE

    Eric Parrado H. /; Paulo Cox P.; Marcelo Fuenzalida C.

    2009-01-01

    The availability of real estate data is clearly limited in Chile, which makes more complex the discussion of the possible vulnerabilities of households and the financial sector to risks arising from real estate markets. This paper proposes a set of housing price indicators for measuring the potential pressures that could be developing in the credit market. Using these price measures, we find that the recent sustained rise in home prices coincides with the sustained increase in disposable inco...

  11. Unmarried cohabitation among deprived families in Chile

    OpenAIRE

    Ramm Santelices, Alejandra Margarita

    2013-01-01

    It is clear that unmarried cohabitation is increasing in Chile. It is less clear what unmarried cohabitation is and why is it rising. In Latin America cohabitation is common among low income groups, and has been described as a surrogate marriage for the disadvantaged. Cohabitation in the region entails conventional gender roles and having children. It has been explained by colonial dominance, poverty, kinship, and machismo. The evidence amassed here indicates that although in practice cohabit...

  12. Equity in health care utilization in Chile

    OpenAIRE

    Núñez, Alicia; Chi, Chunhuei

    2013-01-01

    One of the most extensive Chilean health care reforms occurred in July 2005, when the Regime of Explicit Health Guarantees (AUGE) became effective. This reform guarantees coverage for a specific set of health conditions. Thus, the purpose of this study is to provide timely evidence for policy makers to understand the current distribution and equity of health care utilization in Chile. The authors analyzed secondary data from the National Socioeconomic Survey (CASEN) for the years 1992–2009 an...

  13. Taxonomy Icon Data: Chile pepper [Taxonomy Icon

    Lifescience Database Archive (English)

    Full Text Available Chile pepper Capsicum annuum Capsicum_annuum_L.png Capsicum_annuum_NL.png Capsicum_annuum_S.png Capsicum..._annuum_NS.png http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Capsicum+annuum&t=L htt...p://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Capsicum+annuum&t=NL http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Capsicum...+annuum&t=S http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Capsicum+annuum&t=NS ...

  14. Structural Volatility in Chile: A Policy Report

    OpenAIRE

    Ricardo J. Caballero

    2000-01-01

    This paper identifies Chile's economic weaknesses and offers policy recommendations for increasing stability. Current problems include weak international financial links, a Central Bank mandate that is ill-designed to deal with terms of trade shocks, a propensity to waste scarce liquidity in the banking system; and limited development of financial markets. The paper's policy recommendations include improving external financial links, molding terms of trade contingencies into anti-cyclical pol...

  15. Radiological protection in interventional cardiology in Chile

    International Nuclear Information System (INIS)

    In September 2000, an expert mission was assigned to Chile, under the regional project named 'International BBS in Medical Practices Radiation Protection and Quality Assurance In Interventional Radiology' (ARCAL XLIX). The objective of the mission was to evaluate the level of radiation protection (RP) and safety in interventional cardiology ( IC ) installations. A team of local cardiologists, medical physicists and technologists was created for this purpose and during one week, several cardiology laboratories were evaluated and some basic quality controls (QC) were carried out. A basic pilot training course in radiation protection was imparted at the Hospital of the University of Chile in Santiago de Chile and some of the key objectives for a future national quality assurance programme were presented during the national congress of IC. In addition, a national survey on radiation protection aspects was circulated and its results evaluated. These activities enabled the local team to become familiar with the methodology of assessment of the level of protection and the organization of a programme, which was illustrated with the examples of similar European programmes. As result of these actions, several proposals were made to both the local authorities and the IAEA. The most important were: a) to initiate a basic QC programme, b) to organize a training in RP for cardiologists in order to formalize their accreditation, c) to improve personal occupational dosimetry, d) to initiate a programme of patient dosimetry, e) to optimize the technical and clinical protocols, f) to create a national registry of incidents with skin injuries. (author)

  16. Thermochronology and tectonics of the Mérida Andes and the Santander Massif, NW South America

    Science.gov (United States)

    van der Lelij, Roelant; Spikings, Richard; Mora, Andrés

    2016-04-01

    New apatite U-Pb and multiphase 40Ar/39Ar data constrain the high to medium temperature (~ 500 °C-~ 300 °C) thermal histories of igneous and metamorphic rocks exposed in the Mérida Andes of Venezuela, and new apatite and zircon fission track data constrain the ~ 500 °C-~ 60 °C thermal histories of pre-Jurassic igneous and metamorphic rocks of the adjacent Santander Massif of Colombia. Computed thermal history envelopes using apatite U-Pb dates and grain size information from an Early Palaeozoic granodiorite in the Mérida Andes suggest that it cooled from > 500 °C to histories. The generally accepted timing of amalgamation of Pangaea along the Ouachita-Marathon suture pre-dates Late Permian to Triassic cooling recorded in basement rocks of the Mérida Andes by > 30 Ma, and its effect on rocks preserved in north-western South America is unknown. We interpret late Permian to Triassic cooling in the Mérida Andes to be driven by exhumation. Previous studies have suggested that a short phase of shortening and anatexis is recorded at ~ 253 Ma in the Maya Block, which may have been adjacent to the basement rocks of the Mérida Andes in the Late Permian. The coeval onset of exhumation in the Mérida Andes may be a result of increased coupling in the magmatic arc, which was located along the western margin of Pangaea. Triassic extension is documented in the Central Cordillera of Colombia and Ecuador between ~ 240 Ma and ~ 215 Ma, although extension at this time has not been clearly identified in the Mérida Andes or the Santander Massif. Permian to Triassic cooling is not recorded in the structurally isolated Caparo Block in the southern Mérida Andes, suggesting that it may have constituted a distinct fault block in the Triassic. New fission track data from the Santander Massif suggest that it started exhuming at ~ 40 Ma during a period of accelerated convergence between the Nazca/Farallòn Plate and the western margin of South America. Exhumation in the Santander

  17. Quantifying modern erosion rates and river-sediment contamination in the Bolivian Andes

    Science.gov (United States)

    Vezzoli, Giovanni; Ghielmi, Giacomo; Mondaca, Gonzalo; Resentini, Alberto; Villarroel, Elena Katia; Padoan, Marta; Gentile, Paolo

    2013-08-01

    We use petrographic, mineralogical and geochemical data on modern river sediments of the Tupiza basin in the Bolivian Andes to investigate the relationships among human activity, heavy-metal contamination of sediments and modern erosion rates in mountain fluvial systems. Forward mixing model was used to quantify the relative contributions from each main tributary to total sediment load of the Tupiza River. The absolute sediment load was estimated by using the Pacific Southwest Inter Agency Committee model (PSIAC, 1968) after two years of geological field surveys (2009; 2010), together with data obtained from the Instituto Nacional del Agua public authority (INA, 2007), and suspended-load data from Aalto et al. (2006). Our results indicate that the sediment yield in the drainage basin is 910 ± 752 ton/km2year and the mean erosion rate is 0.40 ± 0.33 mm/year. These values compare well with erosion rates measured by Insel et al. (2010) using 10Be cosmogenic radionuclide concentrations in Bolivian river sediments. More than 40% of the Tupiza river load is produced in the upper part of the catchment, where highly tectonized and weathered rocks are exposed and coupled with sporadic land cover and intense human activity (mines). In the Rio Chilco basin strong erosion of upland valleys produce an increase of erosion (˜10 mm/year) and the influx of large amounts of sediment by mass wasting processes. The main floodplain of the Tupiza catchment represents a significant storage site for the heavy metals (˜657 ton/year). Fluvial sediments contain zinc, lead, vanadium, chromium, arsenic and nickel. Since the residence time of these contaminants in the alluvial plain may be more than 100 years, they may represent a potential source of pollution for human health.

  18. Spatial and temporal variability in denudation across the Bolivian Andes from multiple geochronometers

    Science.gov (United States)

    Insel, Nadja; Ehlers, Todd A.; Schaller, Mirjam; Barnes, Jason B.; Tawackoli, Sohrab; Poulsen, Christopher J.

    2010-10-01

    We quantify spatial and temporal variations in denudation rates across the central Andean fold-thrust belt in Bolivia with particular focus on the Holocene. Measured and predicted 10Be cosmogenic radionuclide (CRN) concentrations in river sediments are used to (1) calculate catchment-averaged denudation rates from 17 basins across two transects at different latitudes, and (2) evaluate the sensitivity of Holocene climate change on the denudation history recorded by the CRN data. Estimated denudation rates vary by two orders of magnitude from 0.04 to 1.93 mm yr - 1 with mean values of 0.40 ± 0.29 mm yr - 1 in northern Bolivia and 0.51 ± 0.50 mm yr - 1 in the south. Results demonstrate no statistically significant correlation between denudation rates and morphological parameters such as relief, slope or drainage basin size. In addition, the CRN-derived denudation rates do not reflect present-day latitudinal variations in precipitation. Comparison to ˜ 130 previously published denudation rates calculated over long (thermochronology-derived; > 10 6 yrs), medium (CRN-derived; 10 2-10 4 yrs), and short timescales (sediment flux-derived; 10 1 yrs) indicate temporal variations in denudation rates that increase between 0 and 200% over the last ˜ 5 ka. CRN modeling results suggest that the CRN-derived denudation rates may not be fully adjusted to wetter climate conditions recorded in the central Andes since the mid-Holocene. We conclude that large spatial variability in CRN denudation may be due to local variations in tectonics (e.g. faulting), while large temporal variability in denudation may be due to temporal variations in climate.

  19. The paradigm of paraglacial megafans of the San Juan river basin, Central Andes, Argentina

    Science.gov (United States)

    Suvires, Graciela M.

    2014-11-01

    The spatial distribution and several morphometric characteristics of the Quaternary alluvial fans of the San Juan River, in the province of San Juan, at the Central and Western part of Argentina, have been studied to classify them as paraglacial megafans, as well to ratify its depositional environmental conditions. The high sedimentary load exported by San Juan river from the Central Andes to the foreland depressions is estimated about 3,682,200 hm3. The large alluvial fans of Ullum-Zonda and Tulum valleys were deposited into deep tectonic depressions, during the Upper Pleistocene deglaciation stages. The outcome of collecting remotely sensed data, map and DEM data, geophysical data and much fieldwork gave access to morphometric, morphographic and morphogenetic data of these alluvial fans. The main drainage network was mapped on processed images using QGis (vers.2.0.1). Several fan morphometric parameters were measured, such as the size, the shape, the thickness, the surface areas and the sedimentary volume of exported load. The analyzed fans were accumulated in deep tectonic depressions, where the alluvium fill reaches 700 to 1200 m thick. Such fans do not reach the large size that other world megafans have, and this is due to tectonic obstacles, although the sedimentary fill average volume surpasses 514,000 hm3. The author proposes to consider Ullum-Zonda and Tulum alluvial fans as paraglacial megafans. According to the stratigraphic relationships of the tropical South American Rivers, the author considers that the San Juan paraglacial megafans would have occurred in the period before 24 ka BP , possibly corresponding to Middle Pleniglacial (ca 65-24ka BP). They record colder and more humid conditions compared with the present arid and dry conditions.

  20. Morphologic evolution of the Central Andes of Peru

    Science.gov (United States)

    Gonzalez, Laura; Pfiffner, O. Adrian

    2012-01-01

    In this paper, we analyze the morphology of the Andes of Peru and its evolution based on the geometry of river channels, their bedrock profiles, stream gradient indices and the relation between thrust faults and morphology. The rivers of the Pacific Basin incised Mesozoic sediments of the Marañon thrust belt, Cenozoic volcanics and the granitic rocks of the Coastal Batholith. They are mainly bedrock channels with convex upward shapes and show signs of active ongoing incision. The changes in lithology do not correlate with breaks in slope of the channels (or knick points) such that the high gradient indices (K) with values between 2,000-3,000 and higher than 3,000 suggest that incision is controlled by tectonic activity. Our analysis reveals that many of the ranges of the Western Cordillera were uplifted to the actual elevations where peaks reach to 6,000 m above sea level by thrusting along steeply dipping faults. We correlate this uplift with the Quechua Phase of Neogene age documented for the Subandean thrust belt. The rivers of the Amazonas Basin have steep slopes and high gradient indices of 2,000-3,000 and locally more than 3,000 in those segments where the rivers flow over the crystalline basement of the Eastern Cordillera affected by vertical faulting. Gradient indices decrease to 1,000-2,000 within the east-vergent thrust belt of the Subandean Zone. Here a correlation between breaks in river channel slopes and location of thrust faults can be established, suggesting that the young, Quechua Phase thrust faults of the Subandean thrust belt, which involve Neogene sediments, influenced the channel geometry. In the eastern lowlands, these rivers become meandering and flow parallel to anticlines that formed in the hanging wall of Quechua Phase thrust faults, suggesting that the river courses were actively displaced outward into the foreland.

  1. High resolution precipitation climatology for the Andes of South Ecuador

    Science.gov (United States)

    Trachte, Katja; Bendix, Jörg

    2014-05-01

    The climate of Ecuador is strongly dominated by the complex structure of the Andes Mountains. Due to their heights and north-south orientation they act like a barrier, which cause delineation between the western and eastern flanks, as well as the inner-Andean areas. Commonly the Ecuadorian climate is classified in three zones, Costa, Interandina and Oriente. Existing precipitation products such as the GPCC or TRMM data are enabled to represent these climate zones, but because of their spatial resolution, they pass to capture the different regimes within a zone. Especially the inner-Andean region (Interandina) with its characteristic complex terrain shows spatially high climate variability. Local circulation systems, e.g. mountain-valley breezes as well as effects of windward and lee-side, drive the climate conditions allowing for the differentiation of air temperature and rainfall distribution on relative small scales. These highly variable patterns are also reflected by the diversity of ecosystems, e.g. rainforest, dry forest and Paramo, in a relative small area. In order to represent the local systems a dynamical downscaling approach for the Ecuadorian region is applied. In doing so the Weather Research and Forecasting (WRF) model is used. A suitable model setup was evaluated within a sensitivity study, where various parametrization schemes were tested. The most suitable physics combination was used for a 30 year hint cast simulation. The poster presents first results of the high resolution climate simulations. On the basis of the spatial distribution of rainfall patterns distinct precipitation regimes within the Interandina will be shown. The aim is to highlight and discuss the importance of the adequately representation of the terrain in mountainous regions like the Andean Mountains.

  2. Erosion by Ice and Water in the Southern Andes

    Science.gov (United States)

    2002-01-01

    This scene on the remote, rugged Argentine/Chilean border in the far southern Andes Mountains offers numerous, dramatic examples of both erosional processes and features of ice and water. The sharp, glaciated crest of the Cerro San Lorenzo (center) exceeds 12,000 feet and casts a long shadow southeastward. Glaciers on its western flank flow into the valley. This Electronic Still Camera photo was taken from the International Space Station, in December 2000 (late spring) when most of the previous winter's snow had melted below an altitude of 6,000 feet. Lago Pueyrredon, and the other lakes visible here, have been excavated by geologically recent episodes of glacier erosion, when glaciers extended all the way onto the lowland plains (top right). Since the last melting of the glaciers (15,000 years ago) three distinct fan deltas (semicircular features, marked with arrows) have formed where rivers flow into the lake. Counterclockwise currents in the lake-driven by strong winds from the west-have generated thin sand spits from each fan-delta. The largest spit (attached to the largest fan-delta, see right arrow) has isolated an approximately 10-kilometer long segment of the south end of the lake. The river that constructed the largest fan presently discharges turbid water to this isolated basin, giving it a lighter color than the rest of the lake. Glacial data collected over the past 50 years indicate that small ice bodies are disappearing at accelerated rates. (EOS, vol 81, no. 24, June 13, 2000) Predictions are that large fluctuations in land ice, with significant implications to society, are possible in the coming decades and centuries due to natural and anthropogenic climate change. Before glacial data can be used to address critical problems pertaining to the world's economic and environmental health, more detailed information about such glaciers is needed. Image ISS001-ESC-5113 provided by the Earth Sciences and Image Analysis Laboratory, Johnson Space Center.

  3. Cretaceous stratigraphy of sierra de Beauvoir, Fuegian Andes, Argentina

    Directory of Open Access Journals (Sweden)

    Daniel R. Martinioni

    2013-03-01

    Full Text Available The Cretaceous stratigraphy north of Lago Fagnano, Tierra del Fuego, was poorly known until the last decade of the twentieth century. Stratigraphic, sedimentologic, and paleontological observations in sierra de Beauvoir and surroundings enabled the recognition of two main packages of dominant marine mudstone. 1 A more than 450 m thick package of slate, shale and mudstone, constituted by the revised Lower Cretaceous Beauvoir Formation. A type locality in the core of sierra de Beauvoir, with diagnostic Aptian-Albian fossils including inoceramids of the Inoceramus neocomiensis group and Aucellina sp., is proposed for this unit. 2 A more than 1,500 m thick, mudstone-dominated, but sandier upward, package consisting of at least three Upper Cretaceous units. Arroyo Castorera Formation (nom. nov. bears Turonian inoceramids of the I. hobetsensis group and I. cf. lamarcki. Río Rodríguez Formation (nom. nov. has Coniacian inoceramids, cf. Cremnoceramus sp. Policarpo Formation bears poorly preserved ammonites (Grossouvrites sp., Maorites sp., and Diplomoceras sp., together with diagnostic Maastrichtian dinocysts (Manumiella spp. complex, Operculodinium cf. azcaratei, some specimens of Fibrocysta-Exochosphaeridium complex, and Palaeocystodinium granulatum. Both packages were deposited in deep-marine environments and show, as a whole, a coarsening upward trend in the succession of Cretaceous rocks. Beauvoir Formation is part of the back-arc basin-fill of the former Rocas Verdes marginal basin. Arroyo Castorera Formation appears as a transition to the initiating Late Cretaceous Austral foreland basin evolution, clearly represented by turbiditic deposits of Río Rodríguez and Policarpo formations that were progressively accumulated in front of the rising Fuegian Andes.

  4. Glacier loss and emerging hydrologic vulnerabilities in the Peruvian Andes

    Science.gov (United States)

    Mark, B. G.; McKenzie, J. M.; Baraer, M.; Lagos, P.; Lautz, L.; Carey, M.; Bury, J.; Crumley, R.; Wigmore, O.; Somers, L. D.

    2015-12-01

    Accelerating glacier recession in the tropical Andes is transforming downstream hydrology, while increasing demands for water by end-users (even beyond the watershed limits) is complicating the assessment of vulnerability. Future scenarios of hydro-climatic vulnerability require a better understanding of coupled hydrologic and human systems, involving both multiscale process studies and more robust models of glacier-climate interactions. We synthesize research in two proglacial valleys of glacierized mountain ranges in different regions of Peru that are both in proximity to growing water usage from urban sectors, agriculture, hydroelectric generation, and mining. In both the Santa River watershed draining the Cordillera Blanca and the Shullcas River watershed below Hyuatapallana Mountain in Junin, glaciers have receded over 25% since the 1980s. Historical runoff and glacier data, combined with glacier-climate modeling, show a long-term decrease in discharge resulting from a net loss of stored water. We find evidence that this altered hydrology is transforming proglacial wetland ecology and water quality, even while water resource use has intensified. Beyond glaciers, our results show that over 60% of the dry season base flow in each watershed is groundwater sourced from heterogeneous aquifers. Municipal water supply in Huancayo already relies on 18 groundwater wells. Perceptions of water availability and actual water use practices remain relatively divorced from the actual water resources provided from each mountain range. Critical changes in glacier volume and water supply are not perceived or acknowledged consistently amongst different water users, nor reflected in water management decisions. In order to identify, understand, model, and adapt to climate-glacier-water changes, it is vital to integrate the analysis of water availability and groundwater processes (the domain of hydrologists) with that of water use (the focus for social scientists). Attention must be

  5. Orographic barriers, high-resolution TRMM rainfall, and relief variations along the eastern Andes

    Science.gov (United States)

    Bookhagen, B.; Strecker, M. R.

    2007-12-01

    The complex interplay between erosion and tectonics shapes landscapes on various time and length scales. Thus, determining the relative importance of tectonic and climate-driven processes is key for our understanding of the evolution of tectonically active mountain belts. Each mountain belt may exhibit an individual and complex response to these processes that may be characteristic for differently sized sectors of the orogenic system. Here, we focus on small (101km) to medium (102-103km) scale relations along the eastern flank of the meridionally oriented South American Andes. The central Andes and the major part of the northern Andes are subject to strong rainfall and erosion on their eastern side. There, rainfall has a strong gradient with wet, northern and central parts and presently drier areas south of the Andes bend at ~17°S. While lithology and geologic units vary along strike, the general deformation regime of the northern and central eastern Andes is similar with east vergent thrust-fault systems. We use high-resolution Tropical Rainfall Measurement Mission (TRMM) and SRTM topographic data to characterize elevation, relief, and hillslope angle of peak rainfall at orographic barriers constituting the eastern flank of the orogen. Over a distance of more than 3500km along the eastern flank of the Andes facing the Amazon Basin, we find that peak rainfall (>3.5m/yr) occurs at a mean elevation of 1.3±0.17km, a mean 3- km-relief of 0.95±0.08km, and areas characterized by moderate mean hillslope angles of 18.3±1.7°. We find that topographic relief is the best first-order rainfall predictor. South of the eastward-convex bend of the Andes, rainfall amounts decrease and there exists no distinct, high rainfall peak. The reduction in rainfall is accompanied by a reduction of relief involving several hundred meters at the mountain front as rivers exiting the eastern Andes tend to form large sedimentary fan systems that reduce the distance between minimum and

  6. Active orogeny of the south-central Andes studied with GPS geodesy Orogenia activa de los Andes centro-australes estudiada mediante geodesia de GPS

    Directory of Open Access Journals (Sweden)

    E. Kendrick

    2006-12-01

    Full Text Available We present GPS measurements of the crustal velocity field in the southern Central Andes between the Santa Cruz corner and the Malargüe fold and thrust belt, and model this interseismic velocity field as the combination of an ephemeral, elastic signal associated with locking of the main plate boundary, and a steady and non-reversing component of displacement associated with localized backarc convergence and growth of the mountain belt. We find that this second component, i.e. the ongoing and permanent displacement of the forearc and the high Andes relative to the craton, can be modeled very well as a steady clockwise rotation of an Andean microplate about a pole located in southern Argentina. Near the Malargüe Basin, this microplate (or block is moving nearly parallel to the strike of the orogen, transporting material towards the bend in the central Andes. Farther north, in the southern limb of the Central Andes, the motion of this same crustal block is directed nearly perpendicular to the strike of the mountain belt. Our results suggest that permanent deformation rates in the backarc range from a maximum of ~ 6-7 mm/yr in the Bolivian Subandes to less than ~ 3 mm/yr in the Argentine Precordillera and Malargue fold and thrust belt. It is likely that most active backarc deformation is accruing in a narrow zone (~ 50 km wide associated with the backarc boundary (usually defined as the thrust front though at this stage it is impossible to distinguish whether specific backarc structures are actively accruing strain.Se presentan mediciones GPS del campo de velocidad en los Andes centro-australes entre el extremo norte de Santa Cruz y la faja plegada de Malargüe. Se modela el campo de velocidad intersísmico como la combinación de una señal elástico/efímera asociada con el anclaje del límite principal de placas, y una componente constante, no reversible de desplazamiento asociada con una convergencia localizada en el retroarco y crecimiento del

  7. Evolución tectonomagmática de los Andes bolivianos Tectonomagmaticevolution of the Bolivian Andes

    Directory of Open Access Journals (Sweden)

    Néstor Jiménez

    2009-10-01

    Full Text Available Los Andes bolivianos ocuparonuna posición de retroarco durante gran parte del Fanerozoico. En su evoluciónse reconoce una primera etapa, restringida al Paleozoico inferior, en la quehubo una gran transferencia de material sedimentario en la corteza superior, yuna segunda en la que predominó el reciclaje de la masa cortical. A lo largodel Paleozoico inferior, una cuenca marina epicratónica se formó entre elcratón de Amazonia, el macizo Arequipa-Antofalla, y el macizo Pampeanofuncionando inicialmente como cuenca de retroarco y luego como cuenca deantepaís hasta colmatarse en el Paleozoico superior. En este lapso ocurrierontres etapas de deformación: La fase oclóyica (límite Ordovícico-Silúrico decarácter restringido, la fase eohercínica (límite Devónico-Carbonífero, y lafase hercínica (Carbonífero Superior también de influencia areal restringida.En el Mesozoico, se registraron aún breves incursiones marinas antes que en elEoceno comience a edificarse una protocordillera. El solevantamiento general detoda la región centroandina, se inició en el Oligoceno Superior afectando alAltiplano y la Cordillera Oriental actuales. Este solevantamiento ocurrió entres etapas limitadas por la formación de superficies de erosión datadas en 18y 10 Ma. La ladera oeste de la Cordillera Oriental, denominada faja de Huarina,tuvo un rol muy importante en la evolución de la región centroandina. Además decobijar a gran parte del magmatismo de retroarco, en esta faja ocurrió la mayorsubsidencia de la cuenca paleozoica. En esta faja ocurrieron preferentementedurante el Mesozoico, procesos de rifting y de adelgazamiento litosférico. Enel Paleógeno, la faja de Huarinas fue la primera en ser solevantada aislando lacuenca altiplánica del interior del continente, y durante el OligocenoSuperior, se constituyó en el cinturón retrocabalgante del orógeno. Ladeformación en el Altiplano y la Cordillera Oriental concluyó hace 10 Ma cuandose form

  8. The giant coastal landslides of Northern Chile: Tectonic and climate interactions on a classic convergent plate margin

    Science.gov (United States)

    Mather, Anne E.; Hartley, Adrian J.; Griffiths, James S.

    2014-02-01

    Documented for the first time are an extensive suite of late Neogene giant terrestrial coastal landslides along the classic convergent margin of western South America (18° to 24° south). These are remarkable in terms of their unusual abundance and atypical setting, such failures previously being linked with oceanic volcanic edifices or over-steepened glaciated coastlines. Located within the hyper-arid Coastal Cordillera of the Atacama Desert of Northern Chile we report the presence of more than 60 individual large-scale landslides with individual volumes up to 9 km3 developed over a horizontal coastline distance of some 650 km. These landslides were emplaced as a combination of rock avalanches and multiple rotational failures. The majority terminated directly into the Pacific - likely generating significant tsunami hazard to the Chilean and south Peruvian coastline in a region which is today considered to be part of a notorious seismic gap. The proliferation and scale of these Late Neogene giant landslides in this actively uplifting, hyperarid terrain suggests they are the main geomorphic agent for relief reduction, probably triggered by megathrust earthquakes and potentially providing a unique palaeoseismic archive. The temporal and spatial distribution of these giant landslides corresponds with a period of surface steepening of the forearc wedge in the Central Andes and south to north differential uplift associated with factors such as aseismic ridge subduction. The resulting surface gradient increases, combined with the persistent climatic aridity of the region, have served to limit effective relief-reducing geomorphic processes in this oversteepened terrain to large-scale landsliding. The phenomena documented here geospatially link previously recognised large-scale slope failures from the off-shore environment and higher altitude areas of the Andean forearc, suggesting that large-scale landsliding is capable of transferring sediment on a regional scale to the

  9. Improved 3D density modelling of the Central Andes from combining terrestrial datasets with satellite based datasets

    Science.gov (United States)

    Schaller, Theresa; Sobiesiak, Monika; Götze, Hans-Jürgen; Ebbing, Jörg

    2015-04-01

    As horizontal gravity gradients are proxies for large stresses, the uniquely high gravity gradients of the South American continental margin seem to be indicative for the frequently occurring large earthquakes at this plate boundary. It has been observed that these earthquakes can break repeatedly the same respective segment but can also combine to form M>9 earthquakes at the end of longer seismic cycles. A large seismic gap left behind by the 1877 M~9 earthquake existed in the northernmost part of Chile. This gap has partially been ruptured in the Mw 7.7 2007 Tocopilla earthquake and the Mw 8.2 2014 Pisagua earthquake. The nature of this seismological segmentation and the distribution of energy release in an earthquake is part of ongoing research. It can be assumed that both features are related to thickness variations of high density bodies located in the continental crust of the coastal area. These batholiths produce a clear maximum in the gravity signal. Those maxima also show a good spatial correlation with seismic asperity structures and seismological segment boundaries. Understanding of the tectonic situation can be improved through 3D forward density modelling of the gravity field. Problems arise in areas with less ground measurements. Especially in the high Andes severe gaps exist due to the inaccessibility of some regions. Also the transition zone between on and offshore date data displays significant problems, particularly since this is the area that is most interesting in terms of seismic hazard. We modelled the continental and oceanic crust and upper mantle using different gravity datasets. The first one includes terrestrial data measured at a station spacing of 5 km or less along all passable roads combined with satellite altimetry data offshore. The second data set is the newly released EIGEN-6C4 which combines the latest satellite data with ground measurements. The spherical harmonics maximum degree of EIGEN-6C4 is 2190 which corresponds to a

  10. A survey of volcano deformation in the central Andes using InSAR: Evidence for deep, slow inflation

    Science.gov (United States)

    Pritchard, M. E.; Simons, M.

    2001-12-01

    We use interferometric synthetic aperture radar (InSAR) to survey about 50 volcanos of the central Andes (15-27o S) for deformation during the 1992-2000 time interval. Because of the remote location of these volcanos, the activity of most are poorly constrained. Using the ERS-1/2 C-band radars (5.6 cm), we observe good interferometric correlation south of about 21o S, but poor correlation north of that latitude, especially in southern Peru. This variation is presumably related to regional climate variations. Our survey reveals broad (10's of km), roughly axisymmetric deformation at 2 volcanic centers with no previously documented deformation. At Uturuncu volcano, in southwestern Bolivia, the deformation rate can be constrained with radar data from several satellite tracks and is about 1 cm/year between 1992 and 2000. We find a second source of volcanic deformation located between Lastarria and Cordon del Azufre volcanos near the Chile/Argentina border. There is less radar data to constrain the deformation in this area, but the rate is also about 1 cm/yr between 1996 and 2000. While the spatial character of the deformation field appears to be affected by atmosphere at both locations, we do not think that the entire signal is atmospheric, because the signal is observed in several interferograms and nearby edifices do not show similar patterns. The deformation signal appears to be time-variable, although it is difficult to determine whether this is due to real variations in the deformation source or atmospheric effects. We model the deformation with both a uniform point-source source of inflation, and a tri-axial point-source ellipsoid, and compare both elastic half-space and layered-space models. We also explore the effects of local topography upon the deformation field using the method of Williams and Wadge (1998). We invert for source parameters using the global search Neighborhood Algorithm of Sambridge (1998). Preliminary results indicate that the sources at both

  11. Extension of the analytic nodal diffusion solver ANDES to triangular-Z geometry and coupling with COBRA-IIIc for hexagonal core analysis

    International Nuclear Information System (INIS)

    In this paper the extension of the multigroup nodal diffusion code ANDES, based on the Analytic Coarse Mesh Finite Difference (ACMFD) method, from Cartesian to hexagonal geometry is presented, as well as its coupling with the thermal-hydraulic (TH) code COBRA-IIIc for hexagonal core analysis. In extending the ACMFD method to hexagonal assemblies, triangular-Z nodes are used. In the radial plane, a direct transverse integration procedure is applied along the three directions that are orthogonal to the triangle interfaces. The triangular nodalization avoids the singularities, that appear when applying transverse integration to hexagonal nodes, and allows the advantage of the mesh subdivision capabilities implicit within that geometry. As for the thermal-hydraulics, the extension of the coupling scheme to hexagonal geometry has been performed with the capability to model the core using either assembly-wise channels (hexagonal mesh) or a higher refinement with six channels per fuel assembly (triangular mesh). Achieving this level of TH mesh refinement with COBRA-IIIc code provides a better estimation of the in-core 3D flow distribution, improving the TH core modelling. The neutronics and thermal-hydraulics coupled code, ANDES/COBRA-IIIc, previously verified in Cartesian geometry core analysis, can also be applied now to full three-dimensional VVER core problems, as well as to other thermal and fast hexagonal core designs. Verification results are provided, corresponding to the different cases of the OECD/NEA-NSC VVER-1000 Coolant Transient Benchmarks.

  12. First web-based database on total phenolics and oxygen radical absorbance capacity (ORAC) of fruits produced and consumed within the south Andes region of South America.

    Science.gov (United States)

    Speisky, Hernan; López-Alarcón, Camilo; Gómez, Maritza; Fuentes, Jocelyn; Sandoval-Acuña, Cristian

    2012-09-12

    This paper reports the first database on antioxidants contained in fruits produced and consumed within the south Andes region of South America. The database ( www.portalantioxidantes.com ) contains over 500 total phenolics (TP) and ORAC values for more than 120 species/varieties of fruits. All analyses were conducted by a single ISO/IEC 17025-certified laboratory. The characterization comprised native berries such as maqui ( Aristotelia chilensis ), murtilla ( Ugni molinae ), and calafate ( Barberis microphylla ), which largely outscored all other studied fruits. Major differences in TP and ORAC were observed as a function of the fruit variety in berries, avocado, cherries, and apples. In fruits such as pears, apples, apricots, and peaches, a significant part of the TP and ORAC was accounted for by the antioxidants present in the peel. These data should be useful to estimate the fruit-based intake of TP and, through the ORAC data, their antioxidant-related contribution to the diet of south Andes populations. PMID:22512599

  13. The Mass Media and Political Socialization: Chile, 1970-2000

    Science.gov (United States)

    Walter, Amy R.

    2005-01-01

    This project seeks to determine the effect of the mass media on political attitudes and behaviors in Chile between the years 1970 and 2000. The relationship between the media and "political socialization" is just now gaining recognition in scholarly research, and Chile offers an excellent case study. This paper traces these two variables during…

  14. Chile - Institutional Design for an Effective Education Quality Assurance

    OpenAIRE

    World Bank

    2007-01-01

    The main objective of this report is to present the Government of Chile with policy options related to the institutional distribution of roles and responsibilities for effective quality assurance in education. Following the introduction, the report is structured as follows. Chapter II presents background information on the evolution of Chile's education system since 1980. This information,...

  15. Chile: Una Vision Politica, Economica y Social (Chile: A Political, Economic, and Social View).

    Science.gov (United States)

    Cortes-Hwang, Adriana

    1972-01-01

    This address seeks to explain in brief the historical background and political, economic, and social conditions leading to the democratic election of a Marxist president in Chile. A historical sketch of Chilean government from independence in 1810 is provided with a description of the situation just before Salvador Allende's election in 1969. Some…

  16. Application of remote sensing to understanding fire regimes and biomass burning emissions of the tropical Andes

    NARCIS (Netherlands)

    Oliveras Menor, I.; Anderson, L.O.; Malhi, Y.

    2014-01-01

    In the tropical Andes, there have been very few systematic studies aimed at understanding the biomass burning dynamics in the area. This paper seeks to advance on our understanding of burning regimes in this region, with the first detailed and comprehensive assessment of fire occurrence and the deri

  17. Climate Change in the High Andes:implications and adaptation strategies for small-scale farmers

    NARCIS (Netherlands)

    Perez, C.; Nicklin, C.; Dangles, O.; Vanek, S.; Sherwood, S.G.; Halloy, S.; Garrett, K.A.; Forbes, G.A.

    2010-01-01

    Abstract: Global climate change represents a major threat to sustainable farming in the Andes. Farmers have used local ecological knowledge and intricate production systems to cope, adapt and reorganize to meet climate uncertainty and risk, which have always been a fact of life. Those traditional sy

  18. Lichenometric dating using Rhizocarpon subgenus Rhizocarpon in the Patagonian Andes, Argentina

    Science.gov (United States)

    Garibotti, Irene Adriana; Villalba, Ricardo

    2009-05-01

    This study represents the first attempt to develop and apply lichenometric dating curves of Rhizocarpon subgenus Rhizocarpon for dating glacier fluctuations in the Patagonian Andes. Six glaciers were studied along the Patagonian Andes. Surfaces of known ages (historical evidences and tree-ring analyses) were used as control sites to develop indirect lichenometric dating curves. Dating curves developed for the studied glaciers show the same general logarithmic form, indicating that growth rate of subgenus Rhizocarpon decreases over time. The strong west-east precipitation gradient across the Andean Cordillera introduces statistically significant differences in the growth curves, with faster growth rates in the moist west sites than the drier eastern sites. Latitudinal difference among the studied glaciers does not appear to be a major factor regulating lichen growth rates. Therefore, we developed two lichenometric curves for dating glacier fluctuations in wetter and drier sites in the Patagonian Andes during the past 450 yrs. Application of the developed curves to moraine dating allowed us to complement glacial chronologies previously obtained by tree-ring analyses. A first chronosequence for moraine formation in the Torrecillas Glacier (42°S) is presented. Our findings confirm the utility of lichenometry to date deglaciated surfaces in the Patagonian Andes.

  19. A NEW LOCALITY OF THE HOODED ANTPITTA (GRALLARICULA CUCULLATA: GRALLARIDAE FOR THE COLOMBIAN CENTRAL ANDES

    Directory of Open Access Journals (Sweden)

    OSCAR HUMBERTO MARÍN GÓMEZ

    2014-05-01

    Full Text Available We report a new locality record of the Hooded Anpitta (Grallariculla cucullata, a threatened species inhabiting montane cloud forests of the Colombian and Venezuelan Andes. This is the first record for Quindío department. We present capture-rate data at this site that suggests a resident, relatively large population. 

  20. Mass Balance of Glaciers In Southern Chile, Based On Dems From Aster and Aerial Photographs

    Science.gov (United States)

    Rivera, A.; Casassa, G.; Bown, F.; Fernandez, A.

    The glaciers located in the Chilean southern Andes region (41-51S) have been re- treating and shrinking during most of the last century, in response to a climate warm- ing trend recognised in many climatic stations of the country. During recent years, several calving and small mountain glaciers have been analysed, in an attempt to cor- relate the short historical glacier variation (no longer than 150 years) with long term dendrochronological series (from 300 to 1000 years). The aim of this analysis is to un- derstand climate change during the last millennia, as well as the mechanisms of glacier response to such climatic changes. In this context, mass balance studies are one of the most important approaches to determine the specific relationship of glaciers to annual and decadal climatic changes. In Chile, only one glacier (glaciar Echaurren, 33S) has been systematically measured since 1975, generating the longest mass balance series of the country. To account for the mass balance of glaciers in the southern region of Chile, a geodetic method is presented, based upon the comparison of digital elevation models (DEM) obtained from aerial photographs and ASTER imagery from different dates. This method have been applied to glaciar Chico located at 49S in the Southern Patagonia Icefield, where we have generated DEMs from aerial photographs of 1975 and 1995, as well as one DEM from an ASTER image of October 2001. The DEMs are geo-referenced to a network of GPS points, measured in several field campaigns carried out during recent years at rock outcrops and in the accumulation area of the glacier. The last campaign was done during September and October 2001, allowing a high accuracy ground control validation for DEM derived from the contemporary ASTER image. The mass balance analysis is complemented with frontal variations derived from Landsat TM imagery, as well as field data and aerial photographs. One preliminary result of this study shows a consistent ice thinning, at