Science.gov

Sample records for chile central mediante

  1. Rainfall erosivity in Central Chile

    NASA Astrophysics Data System (ADS)

    Bonilla, Carlos A.; Vidal, Karim L.

    2011-11-01

    SummaryOne of the most widely used indicators of potential water erosion risk is the rainfall-runoff erosivity factor ( R) of the Revised Universal Soil Loss Equation (RUSLE). R is traditionally determined by calculating a long-term average of the annual sum of the product of a storm's kinetic energy ( E) and its maximum 30-min intensity ( I30), known as the EI30. The original method used to calculate EI30 requires pluviograph records for at most 30-min time intervals. Such high resolution data is difficult to obtain in many parts of the world, and processing it is laborious and time-consuming. In Chile, even though there is a well-distributed rain gauge network, there is no systematic characterization of the territory in terms of rainfall erosivity. This study presents a rainfall erosivity map for most of the cultivated land in the country. R values were calculated by the prescribed method for 16 stations with continuous graphical record rain gauges in Central Chile. The stations were distributed along 800 km (north-south), and spanned a precipitation gradient of 140-2200 mm yr -1. More than 270 years of data were used, and 5400 storms were analyzed. Additionally, 241 spatially distributed R values were generated by using an empirical procedure based on annual rainfall. Point estimates generated by both methods were interpolated by using kriging to create a map of rainfall erosivity for Central Chile. The results show that the empirical procedure used in this study predicted the annual rainfall erosivity well (model efficiency = 0.88). Also, an increment in the rainfall erosivities was found as a result of the rainfall depths, a regional feature determined by elevation and increasing with latitude from north to south. R values in the study area range from 90 MJ mm ha -1 h -1 yr -1 in the north up to 7375 MJ mm ha -1 h -1 yr -1 in the southern area, at the foothills of the Andes Mountains. Although the map and the estimates could be improved in the future by

  2. Petroleum possibilities in continental margin off central Chile

    SciTech Connect

    Gonzalez, E.

    1986-07-01

    The continental margin off central Chile, from Valparaiso to Valdivia, encompassing an area of 100,000 km/sup 2/, has been the target of exploratory activity by Empresa Nacional del Petroleo since 1970. Exploratory drilling began in 1972. By August 1984, total exploratory efforts had resulted in drilling 14 offshore wells and acquiring 12,130 km of seismic reflection lines. A biogenic gas accumulation was discovered in the F well. Because these attempts to find oil were unsuccessful and because drilling costs have escalated, exploratory activities have been curtailed. Forearc basins off central Chile are characterized by low geothermal gradient and a sedimentary filling of Cretaceous and Tertiary strata. Tertiary sequences are characterized by low organic carbon content, immature humic-type organic matter, and a biogenic gas potential. Cretaceous sequences are characterized by higher organic carbon content, good reservoir rocks, and fair to good source rocks. The organic matter is sapropelic, with vitrinite and liptinites, and is favorable for oil and gas generation. Seismic and well data suggest that Mesozoic and Cenozoic sedimentary rock sequences filling the basins (more than 4000 m thick at the shelf edge) extend 40-70 km beyond the present shelf edge. Mesozoic rocks deposited on the slope may generate petroleum and gas that could migrate upslope and accumulate in traps associated with the faulted basement highs and graben-type depressions existing at the shelf edge. This geologic setting favors the development of large petroleum accumulations along the shelf edge and graben on the sedimentary basins off central Chile.

  3. A numerical study of the upwelling circulation off Central Chile

    NASA Astrophysics Data System (ADS)

    Mesias, Jorge M.

    The summer upwelling circulation off Central Chile between 34°--40°S is studied using the Princeton Ocean Circulation numerical model, implemented with realistic atmospheric forcings and bottom topography. The simulations are made for summers of years 1992, 1993, and 1994. Sea surface temperature (SST) from the model results and satellite sensors (derived from NASA/NOAA Pathfinder Project datasets) are compared to determine regions where the numerical simulations more realistically represent the oceanic fields. The summer local winds are predominantly equatorward and fluctuate affected by the seasonal displacement of the Subtropical Anticyclone of the Southeast Pacific. The model ocean circulation shows the presence of a surface coastal equatorward jet flowing over a poleward undercurrent that spreads over the continental shelf and slope break. These currents resemble those historically observed off Central Chile, following a classical Ekman-geostrophy dynamics. The oceanic variability is strongly related to the variability of the local wind forcing, bottom relief, and coastline geometry. Strong wind fluctuations induce the formation of cyclonic/anticyclonic mesoscale eddies, favored by the separation of the equatorward jet from the coast, downstream of a prominent mid-domain cape. The flow variability between regions depends on the spatial variability of the wind forcing. The wind relaxation is larger in the southern regions, where the upwelling tends to disappear. In the northern areas, the separation of the jet and the formation of eddies induce a strong cross-shelf transport activity. Comparisons among SST fields for all years indicate that the model and satellite fields vary in similar patterns, especially in the northern coastal areas, and suggest that oceanic fields are largely affected by changes in local winds during El Nino events. During El Nino periods, the upwelling activity weakens due to a rapid decrease of the equatorward winds, and the passage of

  4. Magnitude Characterization Using Complex Networks in Central Chile

    NASA Astrophysics Data System (ADS)

    Pasten, D.; Comte, D.; Munoz, V.

    2013-12-01

    Studies using complex networks are applied to many systems, like traffic, social networks, internet and earth science. In this work we make an analysis using complex networks applied to magnitude of seismicity in the central zone of Chile, we use the preferential attachment in order to construct a seismic network using local magnitudes and the hypocenters of a seismic data set in central Chile. In order to work with a complete catalogue in magnitude, the data associated with the linear part of the Gutenberg-Richter law, with magnitudes greater than 2.7, were taken. We then make a grid in space, so that each seismic event falls into a certain cell, depending on the location of its hypocenter. Now the network is constructed: the first node corresponds to the cell where the first seismic event occurs. The node has an associated number which is the magnitude of the event which occured in it, and a probability is assigned to the node. The probability is a nonlinear mapping of the magnitude (a Gaussian function was taken), so that nodes with lower magnitude events are more likely to be attached to. Each time a new node is added to the network, it is attached to the previous node which has the larger probability; the link is directed from the previous node to the new node. In this way, a directed network is constructed, with a ``preferential attachment''-like growth model, using the magnitudes as the parameter to determine the probability of attachment to future nodes. Several events could occur in the same node. In this case, the probability is calculated using the average of the magnitudes of the events occuring in that node. Once the directed network is finished, the corresponding undirected network is constructed, by making all links symmetric, and eliminating the loops which may appear when two events occur in the same cell. The resulting directed network is found to be scale free (with very low values of the power-law distribution exponent), whereas the undirected

  5. Late Holocene megathrust earthquakes in south central Chile

    NASA Astrophysics Data System (ADS)

    Garrett, Ed; Shennan, Ian; Gulliver, Pauline; Woodroffe, Sarah

    2013-04-01

    A lack of comprehensive understanding of the seismic hazards associated with a subduction zone can lead to inadequate anticipation of earthquake and tsunami magnitudes. Four hundred and fifty years of Chilean historical documents record the effects of numerous great earthquakes; however, with recurrence intervals between the largest megathrust earthquakes approaching 300 years, seismic hazard assessment requires longer chronologies. This research seeks to verify and extend historical records in south central Chile using a relative-sea level approach to palaeoseismology. Our quantitative, diatom-based approaches to relative sea-level reconstruction are successful in reconstructing the magnitude of coseismic deformation during recent, well documented Chilean earthquakes. The few disparities between my estimates and independent data highlight the possibility of shaking-induced sediment consolidation in tidal marshes. Following this encouraging confirmation of the approach, we quantify land-level changes in longer sedimentary records from the centre of the rupture zone of the 1960 Valdivia earthquake. Here, laterally extensive marsh soils abruptly overlain by low intertidal sediments attest to the occurrence of four megathrust earthquakes. Sites preserve evidence of the 1960 and 1575 earthquakes and we constrain the timing of two predecessors to 1270 to 1410 and 1050 to 1200. The sediments and biostratigraphy lack evidence for the historically documented 1737 and 1837 earthquakes.

  6. Bimodal Recurrence Pattern of Tsunami in South Central Chile

    NASA Astrophysics Data System (ADS)

    Kempf, P.; Moernaut, J.; Van Daele, M. E.; Vandoorne, W.; Messens, F.; Vandenberghe, D.; Pino, M.; Urrutia, R.; De Batist, M. A. O.

    2015-12-01

    Establishing the recurrence time of large-scale tsunami is one of the main objectives of paleotsunami research, as it is fundamental for any tsunami risk assessment. Typically, the result is given in form of the mean recurrence time and a standard deviation as a range of uncertainty, assuming a normally distributed recurrence. We present a 5.5 ka long coastal lake paleotsunami record from south central Chile, which contains 17 tsunami deposits, 9 of which were previously unknown. Our record matches all 3 of the historically known tsunami, as well as all of the 5 known paleotsunami in the region without over- or underrepresentation. We used Bayesian age-depth modelling to calculate an age-depth model and extracted recurrence intervals for 16 recurrence intervals. Our findings confirm the previously published mean tsunami recurrence time on the Valdivia seismic segment of ~300 years. However, our analyses show a strongly bimodal recurrence pattern with one mode at ~115 years and the other mode at ~490 years. The least likely recurrence time between the modes is at ~300 years and coincides with the mean recurrence time. The reasons for the bimodal distribution remain speculative. They can be attributed to either spatial variability, e.g. incomplete segment rupture, splay fault rupture, up- or down-dip rupture, or to temporal variability, e.g. megathrust earthquake clustering, earthquake supercycles. Our findings highlight the importance of recognising the variability in tsunami recurrence patterns before using mean recurrence time for tsunami risk assessment.

  7. Complexity in Size, Recurrence and Source of Historical Earthquakes and Tsunamis in Central Chile

    NASA Astrophysics Data System (ADS)

    Cisternas, M.

    2013-05-01

    Central Chile has a 470-year-long written earthquake history, the longest of any part of the country. Thanks to the early and continuous Spanish settlement of this part of Chile (32°- 35° S), records document destructive earthquakes and tsunamis in 1575, 1647, 1730, 1822, 1906 and 1985. This sequence has promoted the idea that central Chile's large subduction inter-plate earthquakes recur at regular intervals of about 80 years. The last of these earthquakes, in 1985, was even forecast as filling a seismic gap on the thrust boundary between the subducting Nazca Plate and the overriding South America Plate. Following this logic, the next large earthquake in metropolitan Chile will not occur until late in the 21st century. However, here I challenge this conclusion by reporting recently discovered historical evidence in Spain, Japan, Peru, and Chile. This new evidence augments the historical catalog in central Chile, strongly suggests that one of these earthquakes previously assumed to occur on the inter-plate interface in fact occurred elsewhere, and forces the conclusion that another of these earthquakes (and its accompanying tsunami) dwarfed the others. These findings complicate the task of assessing the hazard of future earthquakes in Chile's most populated region.

  8. Chile.

    PubMed

    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

  9. Chile.

    PubMed

    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

  10. Coastal lows and sulfur air pollution in Central Chile

    NASA Astrophysics Data System (ADS)

    Gallardo, L.; Olivares, G.; Langner, J.; Aarhus, B.

    Air pollutants in Santiago (33.5°S, 70.8°W, 500 m a.s.l.), a city with 5 million inhabitants, located in a basin in Central Chile surrounded by the high Andes, frequently exceed air quality standards. This affects human health and it stresses vegetation. The most extreme winter and fall pollution events occur when the subsident regime of the Pacific high is further enhanced by coastal lows (CLs), which bring down the base of the subsidence inversion. Under these conditions, the air quality worsens significantly giving rise to acute air pollution episodes. We assess the ability of a regional transport/chemistry/deposition model (MATCH) coupled to a meteorological model (High Resolution Limited Area Model—HIRLAM) to simulate the evolution of oxidized sulfur (SO x) in connection with intensive CLs. We focus on SO x since it is an environmental issue of concern, and the emissions and concentrations of SO x have been regularly monitored making it easier to bracket model outputs for SO x than for other pollutants. Furthermore, the SO x emissions in the area are very large, i.e., about 0.4% of the global anthropogenic sources. Comparisons with observations indicate that the combination of HIRLAM and MATCH is a suitable tool for describing the regional patterns of dispersion associated with CLs. However, the low number and the limited geographical coverage of reliable air quality data preclude a complete evaluation of the model. Nevertheless, we show evidence of an enhanced contribution of the largest copper smelter in the area, i.e., Caletones, to the burden of SO x in the Santiago basin, especially in the form of sulfate associated to fine particles (diameters <2.5 μm), during CLs. Further, we speculate that the Caletones plume may trigger or promote secondary aerosol formation during CLs in the Santiago basin.

  11. Chile.

    PubMed

    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

  12. Chile.

    PubMed

    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.

  13. A new species of Alsodes (Anura: Alsodidae) from Altos de Cantillana, central Chile.

    PubMed

    Charrier, Andrés; Correa, Claudio; Castro, Camila; Méndez, Marco A

    2015-01-01

    Based on morphological and molecular evidence (mitochondrial and nuclear sequences) we describe a new species of spiny-chest frog, Alsodes cantillanensis, from central Chile (around 34°S). The type locality, Quebrada Infiernillo, is located in the Coastal Range at approximately 65 km from Santiago (Metropolitan Region), the capital of Chile. The distribution of the new species is included entirely in that of A. nodosus (32-36°S approximately), which was identified as the sister taxon according to molecular phylogenetic analyses. Moreover, both species are sympatric in the type locality. The new species was found in a Nothofagus macrocarpa relict forest potentially threatened by gold mining activities. We identify other threats for its conservation and some biological data needed for understanding the evolution of this species. This discovery reveals the scarce knowledge about biogeography, evolution and ecology of spiny-chest frogs from central Chile

  14. The Evolution of Seabirds in the Humboldt Current: New Clues from the Pliocene of Central Chile

    PubMed Central

    Chávez Hoffmeister, Martín; Carrillo Briceño, Jorge D.; Nielsen, Sven N.

    2014-01-01

    Background During the last decade, new Neogene fossil assemblages from South America have revealed important clues about the evolution of seabird faunas in one of the major upwelling systems of the world: the Humboldt Current. However, most of this record comes from arid Northern Chile and Southern Peru and, in consequence, our knowledge of the evolutionary history of seabirds in the temperate transitional zone is negligible. A new Late Pliocene assemblage of fossil birds from the coastal locality of Horcon in Central Chile offers a unique opportunity to fill this gap. Principal Findings Isolated bones of a medium-sized penguin are the most abundant bird remains. Morphological and cladistic analyses reveal that these specimens represent a new species of crested penguin, Eudyptes calauina sp. nov. Eudyptes is a penguin genus that inhabit temperate and subantarctic regions and currently absent in central Chile. Additionally, a partial skeleton of a small species of cormorant and a partial tarsometatarsus of a sooty shearwater have been identified. Conclusion/Significance The Horcon fossils suggest the existence of a mixed avifauna in central Chile during the Pliocene in concordance with the latitudinal thermal gradient. This resembles the current assemblages from the transitional zone, with the presence of species shared with Northern Chile and Southern Peru and a previously unrecorded penguin currently absent from the Humboldt System but present in the Magellanic region. Comparison of Pliocene seabird diversity across the Pacific coast of South America shows that the Horcon avifauna represents a distinctive assemblage linking the living faunas with the Late Miocene ones. A comparison with the fossil record near the Benguela Current (west coast of southern Africa) suggests that the thermic gradient could play an important role in the preservation of a higher diversity of cold/temperate seabirds in the Humboldt Current. PMID:24621560

  15. Impact of Intrathermocline eddies on seamount and oceanic island off Central Chile: Observation and modeling

    NASA Astrophysics Data System (ADS)

    Hormazabal, Samuel; Morales, Carmen; Cornejo, Marcela; Bento, Joaquim; Valencia, Luis; Auger, Pierre; Rodriguez, Angel; Correa, Marco; Anabalón, Valeria; Silva, Nelson

    2016-04-01

    In the Southeast Pacific, oceanographic processes that sustain the biological production necessary to maintain the ecosystems associated to seamounts and oceanic islands are still poorly understood. Recent studies suggest that the interaction of mesoscale and submesoescale eddies with oceanic islands and seamounts could be playing an important role in the time-space variability of primary production. In this work, research cruises, satellite data and Regional Ocean Modeling System (ROMS) results have been used to describe the main characteristics of intrathermocline eddies (ITE) and their impact on the Juan Fernández archipelago (JFA), off central Chile. The JFA is located off the coast of central Chile (33°S), and is composed of three main islands: Robinson Crusoe (RC), Alejandro Selkirk (AS) and Santa Clara (SC). Between the RC and AS are located the westernmost seamounts (JF6 and JF5) of the Juan Fernández archipelago. Satellite altimetry data (sea surface height from AVISO) were used to detect and track mesoscale eddies through eddy-tracking algorithm. Physical, chemical and biological parameters as temperature, salinity, dissolved oxygen and fluorescence were measured in the water column at JF5 and JF6, and along the coast off central Chile (30-40°S). Results from the research cruise exhibit the interaction between an ITE and the seamount JF6. Eddy-tracking results showed that the ITE observed at the JF6 was formed at the coast off central-southern Chile, traveled ~900 km seaward and after ~9 months reached the JF5 and JF6 region. Observations along the Chilean coast confirmed that the coast corresponds to the formation area of the observed ITE. In this region, ITEs are represented by subsurface lenses (~100 km diameter; 400 m thickness) of homogeneous salinity, nutrient rich and oxygen-poor equatorial subsurface water mass (ESSW) which is transported poleward by the Peru-Chile undercurrent in the coastal band and seaward by ITEs. The effect of ITEs on the

  16. Modelling the seasonal dynamics of the Peru-Chile Undercurrent off Central Chile (30-40°S)

    NASA Astrophysics Data System (ADS)

    Vergara, Odette A.; Echevín, Vincent; Sepúlveda, Héctor H.; Colas, Francois; Quiñones, Renato A.

    2016-07-01

    The seasonal variability of the hydrology and the poleward subsurface Peru-Chile Undercurrent (PCUC) off the central Chilean coast (29-41°S) were examined using a high-resolution regional model. The model realistically reproduced observed sea level variability, such as intense anticyclonic eddies, the offshore intensification of the poleward flow and the reduced nearshore equatorward flow during autumn, as well as the equatorward intensification of nearshore meandering flow during spring. Values for geostrophic eddy kinetic energy were high along the coast between 30° and 37°S, and lower south of this area. The modelled poleward undercurrent showed latitudinal variability in velocity and transport. The maximum average transport reported was 0.8 Sv near 30°S, consistent with previous modelling studies and estimations derived from in situ observations. The poleward reduction in undercurrent strength was shown to be partly generated by the poleward decrease in wind stress curl and by the formation of a westward jet near 35°S associated with westward-propagating eddies. A Lagrangian analysis of the modelled water parcels transported by the undercurrent shows that only 14-20% of the subsurface floats transported by the undercurrent upwelled into the surface layer within the subsequent six months after their release. The floats remaining within the subsurface layer were likely transported further south by the current, offshore by westward-propagating eddies or equatorward by the deeper part of the surface coastal current.

  17. A seismological study of the 1835 seismic gap in south-central Chile

    NASA Astrophysics Data System (ADS)

    Campos, J.; Hatzfeld, D.; Madariaga, R.; Lopez, G.; Kausel, E.; Zollo, A.; Iannacone, G.; Fromm, R.; Barrientos, S.; Lyon-Caen, H.

    2002-09-01

    We study the possible seismic gap in the Concepción-Constitución region of south-central Chile and the nature of the M=7.8 earthquake of January 1939. From 1 March to 31 May 1996 a seismic network of 26 short period digital instruments was deployed in this area. We located 379 hypocenters with rms travel time residuals of less than 0.50 s using an approximate velocity distribution. Using the VELEST program, we improved the velocity model and located 240 high precision hypocenters with residuals less than 0.2 s. The large majority of earthquakes occurred along the Wadati-Benioff zone along the upper part of the downgoing slab under central Chile. A few shallow events were recorded near the chain of active volcanos on the Andes; these events are similar to those of Las Melozas near Santiago. A few events took place at the boundary between the coastal ranges and the central valley. Well constrained fault plane solutions could be computed for 32 of the 240 well located events. Most of the earthquakes located on the Wadati-Benioff zone had "slab-pull" fault mechanism due to tensional stresses sub-parallel to the downgoing slab. This "slab-pull" mechanism is the same as that of eight earthquakes of magnitude around 6 that are listed in the CMT catalog of Harvard University for the period 1980-1998. This is also the mechanism inferred for the large 1939 Chilean earthquake. A very small number of events in the Benioff zone had "slab-push" mechanisms, that is events whose pressure axis is aligned with the slab. These events are found in double layered Wadati-Benioff zones, such as in northern Chile or Japan. Our spatial resolution is not good enough to detect the presence of a double layer, but we suspect there may be one.

  18. Sea surface thermal structure associated to the small pelagic fish resources distribution in Central Chile

    SciTech Connect

    Yanez, E.; Barbieri, M.A.; Catasti, V.

    1997-06-01

    A survey study was conducted to assess the possibility of introducing the use of sea surface temperatures (SST), obtained from NOAA satellite data, for the small pelagic fisheries resources in Central Chile. Relationships between species yields and thermics gradients (GRT) were found significant. Jack mackerel (Trachuru murphyi) yields were largely related with a strong thermal gradient next to oceanic waters, while anchovy (Engraulis ringens) and common sardine (Clupea bentincki) yields were mainly associated to the development of coastal upwelling events. It is concluded that the use of SST-NOAA images can play an important role in fleet operations, particularly in the case of the kind of boats considered in this paper.

  19. Mass balance and hydrological contribution of glaciers in northern and central Chile

    NASA Astrophysics Data System (ADS)

    MacDonell, Shelley; Vivero, Sebastian; McPhee, James; Ayala, Alvaro; Pellicciotti, Francesca; Campos, Cristian; Caro, Dennys; Ponce, Rodrigo

    2016-04-01

    Water is a critical resource in the northern and central regions of Chile, as the area supports more than 40% of the country's population, and the regional economy depends on agricultural production and mining, which are two industries that rely heavily on a consistent water supply. Due to relatively low rates of rainfall, meltwater from snow and ice bodies in the highland areas provides a key component of the annual water supply in these areas. Consequently, accurate estimates of the rates of ablation of the cryosphere (i.e. snow and ice) are crucial for predicting current supply rates, and future projections. Whilst snow is generally a larger contributor of freshwater, during periods of drought, glaciers provide a significant source. This study aims to determine the contribution of glaciers to two catchments in northern and central Chile during a 2.5 year period, which largely consisted of extreme dry periods, but also included the recent El Niño event. This study combined field and modelling studies to understand glacier and rock glacier contributions in the Tapado (30°S), Yeso (33°S) catchments. In the field we undertook glaciological mass balance monitoring of three glaciers, monitored albedo and snow line changes using automatic cameras for three glaciers, measured discharge continuously at several points, installed six automatic weather stations and used thermistors to monitor thermal regime changes of two rock glaciers. The combination of these datasets where used to drive energy balance and hydrological models to estimate the contribution of ice bodies to streamflow in the two studied catchments. Over the course of the study all glaciers maintained a negative mass balance, however glaciers in central Chile lost more mass, which is due to the higher melt rates experienced due to lower elevations and higher temperatures. Areas free of debris generally contributed more to streamflow than sediment covered regions, and snow generally contributed more over

  20. Comparison of soil microbial communities inhabiting vineyards and native sclerophyllous forests in central Chile.

    PubMed

    Castañeda, Luis E; Godoy, Karina; Manzano, Marlene; Marquet, Pablo A; Barbosa, Olga

    2015-09-01

    Natural ecosystems provide services to agriculture such as pest control, soil nutrients, and key microbial components. These services and others in turn provide essential elements that fuel biomass productivity. Responsible agricultural management and conservation of natural habitats can enhance these ecosystem services. Vineyards are currently driving land-use changes in many Mediterranean ecosystems. These land-use changes could have important effects on the supporting ecosystems services related to the soil properties and the microbial communities associated with forests and vineyard soils. Here, we explore soil bacterial and fungal communities present in sclerophyllous forests and organic vineyards from three different wine growing areas in central Chile. We employed terminal restriction fragment length polymorphisms (T-RFLP) to describe the soil microbial communities inhabiting native forests and vineyards in central Chile. We found that the bacterial community changed between the sampled growing areas; however, the fungal community did not differ. At the local scale, our findings show that fungal communities differed between habitats because fungi species might be more sensitive to land-use change compared to bacterial species, as bacterial communities did not change between forests and vineyards. We discuss these findings based on the sensitivity of microbial communities to soil properties and land-use change. Finally, we focus our conclusions on the importance of naturally derived ecosystem services to vineyards.

  1. Comparison of soil microbial communities inhabiting vineyards and native sclerophyllous forests in central Chile.

    PubMed

    Castañeda, Luis E; Godoy, Karina; Manzano, Marlene; Marquet, Pablo A; Barbosa, Olga

    2015-09-01

    Natural ecosystems provide services to agriculture such as pest control, soil nutrients, and key microbial components. These services and others in turn provide essential elements that fuel biomass productivity. Responsible agricultural management and conservation of natural habitats can enhance these ecosystem services. Vineyards are currently driving land-use changes in many Mediterranean ecosystems. These land-use changes could have important effects on the supporting ecosystems services related to the soil properties and the microbial communities associated with forests and vineyard soils. Here, we explore soil bacterial and fungal communities present in sclerophyllous forests and organic vineyards from three different wine growing areas in central Chile. We employed terminal restriction fragment length polymorphisms (T-RFLP) to describe the soil microbial communities inhabiting native forests and vineyards in central Chile. We found that the bacterial community changed between the sampled growing areas; however, the fungal community did not differ. At the local scale, our findings show that fungal communities differed between habitats because fungi species might be more sensitive to land-use change compared to bacterial species, as bacterial communities did not change between forests and vineyards. We discuss these findings based on the sensitivity of microbial communities to soil properties and land-use change. Finally, we focus our conclusions on the importance of naturally derived ecosystem services to vineyards. PMID:26445647

  2. Interseismic coupling, segmentation and mechanical behavior of the Central Chile subduction zone.

    NASA Astrophysics Data System (ADS)

    Métois, M.; Socquet, A.; Vigny, C.

    2012-04-01

    Global Positioning System (GPS) measurements carried out in Chile over the last two decades showed that an entire portion of the Nazca-South America subduction zone (38°S-24°S) was locked over this period of time. The induced accumulation of elastic deformation in the upper-plate was not released until the recent Maule earthquake of 27 February 2010 (Mw 8.8) that ruptured the southern part of this section. Locking or coupling between the two plates varies both with depth and along strike. Here we use our own GPS data (an updated solution of our extended network in central Chile), combined with other published data sets, to quantify the spatial variations of the coupling that prevailed before the Maule earthquake. Using a simple elastic model based on the back-slip assumption, we show that coupling variations on the subduction plane are sufficient to explain the observed surface deformation, with no need of a sliver in central Chile. We identify four segments characterized by higher coupling and separated by narrow areas of lower coupling. This segmentation is in good agreement with historical and recent seismicity in Chile. In particular, the La Serena Bay (30°S-28°S) where the locked zone vanishes is a stable boundary where historical events stopped. The Maule region that ruptured in feb. 27th of 2010 (Mw 8.8) from 38 S to 34 S, was characterized by a well developped fully locked zone that extents far indepth and narrows where the earthquake stopped propagating (San Antonio at 34°S and south of Arauco peninsula at 38°S). These narrow zones of lower coupling are often associated with irregular bathymetric or coastal features (fracture zones or peninsulas). Finally, coseismic and early post-seismic slip distribution of the Maule earthquake, occurring either in previously highly or weakly coupled zones, map a complex distribution of velocity-weakening and velocity-strengthening patches on the subduction interface.

  3. Coastal evidence for Holocene subduction-zone earthquakes and tsunamis in central Chile

    USGS Publications Warehouse

    Dure, Tina; Cisternas, Marco; Horton, Benjamin; Ely, Lisa; Nelson, Alan R.; Wesson, Robert L.; Pilarczyk, Jessica

    2015-01-01

    The ∼500-year historical record of seismicity along the central Chile coast (30–34°S) is characterized by a series of ∼M 8.0–8.5 earthquakes followed by low tsunamis (<4 m) occurring on the megathrust about every 80 years. One exception is the AD 1730 great earthquake (M 9.0–9.5) and high tsunami (>10 m), but the frequency of such large events is unknown. We extend the seismic history of central Chile through a study of a lowland stratigraphic sequence along the metropolitan coast north of Valparaíso (33°S). At this site, higher relative sea level during the mid Holocene created a tidal marsh and the accommodation space necessary for sediment that preserves earthquake and tsunami evidence. Within this 2600-yr-long sequence, we traced six laterally continuous sand beds probably deposited by high tsunamis. Plant remains that underlie the sand beds were radiocarbon dated to 6200, 5600, 5000, 4400, 3800, and 3700 cal yr BP. Sediment properties and diatom assemblages of the sand beds—for example, anomalous marine planktonic diatoms and upward fining of silt-sized diatom valves—point to a marine sediment source and high-energy deposition. Grain-size analysis shows a strong similarity between inferred tsunami deposits and modern coastal sediment. Upward fining sequences characteristic of suspension deposition are present in five of the six sand beds. Despite the lack of significant lithologic changes between the sedimentary units under- and overlying tsunami deposits, we infer that the increase in freshwater siliceous microfossils in overlying units records coseismic uplift concurrent with the deposition of five of the sand beds. During our mid-Holocene window of evidence preservation, the mean recurrence interval of earthquakes and tsunamis is ∼500 years. Our findings imply that the frequency of historical earthquakes in central Chile is not representative of the greatest earthquakes and tsunamis that the central Chilean subduction zone has

  4. Intrathermocline eddies in the coastal transition zone off central Chile (31-41°S)

    NASA Astrophysics Data System (ADS)

    Hormazabal, Samuel; Combes, Vincent; Morales, Carmen E.; Correa-Ramirez, Marco A.; Di Lorenzo, Emmanuel; Nuñez, Sergio

    2013-10-01

    The three-dimensional structure and the origin of mesoscale anticyclonic intrathermocline eddies (ITEs) in the coastal transition zone (CTZ) off central Chile (31-41°S) were analyzed through the combination of data from oceanographic cruises and satellite altimetry, and the application of an eddy-resolving primitive equation ocean model coupled with a numerical experiment using a passive tracer. In this region, ITEs are represented by subsurface lenses (˜100 km diameter; 500 m thickness or vertical extension) of nearly homogeneous salinity (>34.5) and oxygen-deficient (<1.0 mL L-1) waters, properties which are linked to the equatorial subsurface water mass (ESSW) transported poleward by the Peru-Chile undercurrent (PCUC) in the coastal band. At least five to seven ITEs were observed simultaneously in the area between 31° and 38°S during winter cruises in 1997 and 2009. Satellite data indicated that the ITEs identified from in situ data moved westward, each at a mean speed of ˜2 km d-1 and transported a total volume of ˜1 × 106 m3 s-1 (=1 Sv); the lifespan of each ITE ranged from a few months to 1 year. Model results indicate that ITEs become detached from the PCUC under summer upwelling conditions in the coastal zone.

  5. Add-on conservation benefits of marine territorial user rights fishery policies in central Chile.

    PubMed

    Gelcich, Stefan; Godoy, Natalio; Prado, Luis; Castilla, Juan Carlos

    2008-01-01

    To combine the rational use of marine benthic resources and economic development of small-scale fishers, Chile passed legislation in 1991 establishing a comanagement policy that grants exclusive territorial user rights for fisheries (TURFs) to artisanal fisher organizations in well-defined inshore coastal areas, known as Management and Exploitation Areas for Benthic Resources (MEABRs). In general the policy has been proclaimed a management and economic success because benthic resource abundances have increased inside MEABRs in comparison with open-access areas. However, there is a lack of studies assessing the impact of this management policy on nontargeted subtidal species and community assemblages and the policy's implications for biodiversity and conservation. This study starts to fill this gap and links the allocation of TURFs for benthic resources with add-on conservation benefits for species that are not directly linked with the fishery policy. Comparative subtidal surveys inside vs. outside MEABRs were used to assess the effects of three MEABRs on managed targeted benthic species, biodiversity (species richness), and community assemblages in central Chile. Surveys focused exclusively on subtidal kelp forest habitats dominated by Lessonia trabeculata, spanning 4-12 m in depth and with similar levels of habitat complexity. The study comprised: (1) quantification of kelp forest complexity, (2) understory survey of sessile species, (3) quantification of conspicuous benthic macroinvertebrates, including those under management, and (4) quantification of reef-fish species inside the kelp habitat. Results showed population enhancement of target-managed invertebrates inside MEABRs. Moreover, reef-fish species were significantly more diverse and abundant inside MEABRs, and community assemblages of nontarget benthic invertebrates and reef fish were significantly different inside vs. outside MEABRs. The comanagement of inshore benthic resources in Chile, through MEABRs

  6. The 2010 Mw 8.8 Maule megathrust earthquake of Central Chile, monitored by GPS.

    PubMed

    Vigny, C; Socquet, A; Peyrat, S; Ruegg, J-C; Métois, M; Madariaga, R; Morvan, S; Lancieri, M; Lacassin, R; Campos, J; Carrizo, D; Bejar-Pizarro, M; Barrientos, S; Armijo, R; Aranda, C; Valderas-Bermejo, M-C; Ortega, I; Bondoux, F; Baize, S; Lyon-Caen, H; Pavez, A; Vilotte, J P; Bevis, M; Brooks, B; Smalley, R; Parra, H; Baez, J-C; Blanco, M; Cimbaro, S; Kendrick, E

    2011-06-17

    Large earthquakes produce crustal deformation that can be quantified by geodetic measurements, allowing for the determination of the slip distribution on the fault. We used data from Global Positioning System (GPS) networks in Central Chile to infer the static deformation and the kinematics of the 2010 moment magnitude (M(w)) 8.8 Maule megathrust earthquake. From elastic modeling, we found a total rupture length of ~500 kilometers where slip (up to 15 meters) concentrated on two main asperities situated on both sides of the epicenter. We found that rupture reached shallow depths, probably extending up to the trench. Resolvable afterslip occurred in regions of low coseismic slip. The low-frequency hypocenter is relocated 40 kilometers southwest of initial estimates. Rupture propagated bilaterally at about 3.1 kilometers per second, with possible but not fully resolved velocity variations. PMID:21527673

  7. Clonal distribution of Streptococcus suis isolated from diseased pigs in the central region of Chile

    PubMed Central

    Morales, Bárbara; Ruiz, Álvaro; Lacouture, Sonia; Gottschalk, Marcelo

    2015-01-01

    The characteristics of 29 Chilean field strains of Streptococcus suis recovered between 2007 and 2011 from pigs with clinical signs at different farms were studied. Serotyping with use of the coagglutination test revealed that all but 1 strain belonged to serotype 6; the remaining strain was serotype 22. All the serotype-6 strains were suilysin (hemolysin)-negative; in addition, they were found to be genotypically homogeneous by enterobacterial repetitive intergenic consensus sequence-based polymerase chain reaction (ERIC-PCR) and sensitive to ampicillin, ceftiofur, penicillin, and trimethoprim/sulfamethoxazole. The results indicate that, in contrast to what is generally observed in other countries, a single clone of S. suis was isolated from diseased pigs in the central region of Chile. PMID:26424917

  8. Population genetic structure of codling moth (Lepidoptera: Tortricidae) from apple orchards in central Chile.

    PubMed

    Fuentes-Contreras, Eduardo; Espinoza, Juan L; Lavandero, Blas; Ramírez, Claudio C

    2008-02-01

    Codling moth, Cydia pomonella (L.) (Lepidoptera: Tortricidae), is the main pest of pome fruits worldwide. Despite its economic importance, little is known about the genetic structure and patterns of dispersal at the local and regional scale, which are important aspects for establishing a control strategy for this pest. An analysis of genetic variability using microsatellites was performed for 11 codling moth populations in the two major apple (Malus domestica Borkh) cropping regions in central Chile. Despite the geographical distances between some populations (approximately 185 km), there was low genetic differentiation among populations (F(ST) = 0.002176), with only slight isolation by distance. Only approximately 0.2% of the genetic variability was found among the populations. Geographically structured genetic variation was independent of apple orchard management (production or abandoned). These results suggest a high genetic exchange of codling moth between orchards, possibly mediated by human activities related to fruit production. PMID:18330135

  9. Bias correction of daily precipitation in south-central Chile using NCEP CFSv2

    NASA Astrophysics Data System (ADS)

    Maass, T.; castro Heredia, L. M.; Suarez, F. I.; Fernandez, B.

    2015-12-01

    Hydroelectric power plant operations are heavily influenced by the streamflow forecasts on their basins. In Chile, these forecasts are based on historical observations. However, this approach has reached its limit of quality and reliability, being difficult to adapt to current weather conditions (climate change), to extreme weather conditions, and to ungauged basins. In this work, we evaluated the bias correction of NCEP-CSv2 daily precipitation with the aim of incorporating this forecast into a real-time hydrological forecasting system. Bias correction was performed using two approaches of the Quantile Mapping (QM) method: a) a polynomial fit (APo) applied to the differences between the forecasted and observed cumulative distribution functions (CDFs) for the training period; and b) using a Gamma probability distribution (APb) to fit the forecasted and observed CDFs. The bias correction was applied at two locations in south-central Chile: over the valley and in the Andes mountains. To estimate the CDFs and the QM fitting models in the training period, historical records and data from the CFSv2 Reforecast model (between 1995 and 2009) were used. The bias correction evaluation was done between 2011 and 2014 with the forecast of the CFSv2 model. The uncorrected CFSv2 results show that the mid-term forecasts (six months) have a high correlation (r>0.5) for the first days of the forecast (2 weeks), but an important underestimation in the observed data from both the valley and the mountain. After applying the bias correction (APo or APb), the errors of the corrected forecasts decrease in relation to the uncorrected CFSv2 forecasts, with a noticeable improvement for the first forecasted days (being the APo errors lower than those of the APb). In the long term, and as might be expected, the errors increase: the peak precipitation is underestimated and the null rainfall is overestimated.

  10. Wide-Angle Seismic Experiment Across the Oeste Fault Zone, Central Andes, Northern Chile.

    NASA Astrophysics Data System (ADS)

    Lorenzo, J. M.; Yáñez, G. A.; Vera, E. E.; Sepúlveda, J.

    2008-12-01

    From December 6-21, 2007, we conducted a 3-component, radio-telemetric, seismic survey along a ~ 15-km wide E-W transect in the Central Andes, at a latitude of ~ 22.41° S, centered north of the city of Calama (68.9° W), Chile. The study area is sandwiched between the Central Depression in the west and the Andean Western Cordillera of Chile. Recording stations, nominally spaced at intervals of either 125 or 250 m collected up to 3.5 s of refracted seismic arrivals at maximum source-receiver offsets exceeding 15 km. Ten shothole sources, spaced 2-6 km apart focused energy on the shallow (0-3 km), crustal, Paleogene-age structures. Preliminary, tomographic inversions of refracted first arrivals show the top of a shallow (< 1km), high- velocity (VP, ~5 km/s) crust, deepening sharply eastward to at least 2 km. At the surface, this central basement step correlates to a regionally extensive (> 600 km), strike-slip fault zone known as the Oeste fault. Turning ray densities suggest the base of the overlying velocity gradient unit (VP, 2-4 km/s) dips inwardly from both east and west directions toward the Oeste fault to depths of almost 1 km. Plate reorganization commencing at least by the latter half of the Oligocene led from oblique to more orthogonal convergence between the South American and the Nazca (Farallon) Plates. We interpret previously mapped, older, minor faults as being generated within the right-lateral, orogen-parallel, Oeste strike-slip fault zone, and postdated by Neogene, N-S striking thrust faults. In this context we also interpret that the spatial distribution of velocity units requires an period of extensional activity that may (1) postdate the transpressional strike slip fault activity of the Neogene, (2) be related to a later releasing bend through the translation and interaction of rigid blocks hidden at depth or even (3) be the consequence of inelastic failure from the result of flexural loading.

  11. Recurrent giant earthquakes in South-Central Chile revealed by lacustrine sedimentary records

    NASA Astrophysics Data System (ADS)

    Moernaut, J.; de Batist, M. A.; Heirman, K.; van Daele, M.; Brümmer, R.; Pino, M.; Urrutia, R.; Wolff, C.; Brauer, A.; Roberts, S.; Kilian, R.

    2009-12-01

    Megathrust (‘giant’) earthquakes in the South-Central Chilean subduction zone (e.g. 1960 earthquake; Mw: 9.5) cause landslides, tsunamis, soil liquefaction, coastal uplift/subsidence, volcanic eruptions, all of which pose a major threat to society. A reliable seismic hazard assessment requires establishing if such mega-events occurred in the past and determining their recurrence pattern. The Lake District (39-42°S) in South-Central Chile, located in the northern half of the 1960 earthquake rupture zone, contains several large, steep-sloped glacigenic lakes with high sedimentation rates, and whose sedimentary deposits are highly susceptible to earthquake-triggered slope instability. To establish the reoccurrence interval of earthquakes during the Late Holocene, we mapped the spatial distribution of seismically-induced sedimentary ‘event’ deposits and structures in each lake using very-high resolution seismic data, and collected a series of short gravity cores and long piston cores. Multi-proxy sedimentary analyses (color, magnetic susceptibility, density, geochemistry, grain size), radiocarbon dating, varve-counting, and tephro-stratigraphy were used to identify ‘event’ deposits in each core and correlate paleoseismic horizons across basins. The sediment sequences investigated contain four main types of earthquake-induced structures: 1) multiple mass-wasting deposits on a single stratigraphic level, which are relicts of a basin-wide, subaqueous slope instability ‘event’; 2) homogenite deposits in the deepest parts of steep basins indicative of lake seiches and tsunamis; 3) fluid-escape structures (e.g. sediment volcanoes), which reflect sudden liquefaction in buried mass-wasting deposits and subsequent vertical fluidization flow; 4) in-situ deformed units (e.g., contorted bedding) in nearly-flat layers, which reflect strong horizontal ground acceleration events. Comparison with historical earthquakes suggests the spatial extent, thickness, nature of

  12. Pelagic resources landings in central-southern Chile under the A2 climate change scenarios

    NASA Astrophysics Data System (ADS)

    Yáñez, Eleuterio; Plaza, Francisco; Silva, Claudio; Sánchez, Felipe; Barbieri, María Ángela; Aranis, Antonio

    2016-09-01

    Artificial neural networks (ANNs) were used to predict landings of anchovy (Engraulis ringens), common sardine (Strangomera bentincki), and jack mackerel (Trachurus murphyi) in central-southern Chile. Twelve environmental variables were considered along with fishing effort (fe) and landing statistics from 1973 to 2012. During external validation, the best models with all of the selected variables gave r 2 values of 90 % for anchovy, 96 % for common sardine, and 88 % for jack mackerel. The models were simplified by considering only fe and sea surface temperature from NCEP/NCAR reanalysis data (SST-NOAA), and very similar fits were achieved (87, 92, and 88 %, respectively). Future SSTs were obtained from the A2 climate change scenario and regionalized using statistical downscaling techniques. The downscaled SSTs were used as input for landings predictions using ANN simplified models. In addition, three scenarios of future fishing efforts (2010-2012 average, average + 50 %, and average - 50 %) were used as the input data for landing simulations. The results of the predictions show a decrease of 9 % in future landings of sardine and an increase of 17 % for jack mackerel when comparing 2015 and 2065 monthly projections. However, no significant differences are shown when comparing the estimated landings for the three fishing effort scenarios. Finally, more integrative and complex conceptual models that consider oceanographic-biophysical, physiological, environmental-resource, and interspecies processes need to be implemented.

  13. Pelagic resources landings in central-southern Chile under the A2 climate change scenarios

    NASA Astrophysics Data System (ADS)

    Yáñez, Eleuterio; Plaza, Francisco; Silva, Claudio; Sánchez, Felipe; Barbieri, María Ángela; Aranis, Antonio

    2016-10-01

    Artificial neural networks (ANNs) were used to predict landings of anchovy ( Engraulis ringens), common sardine ( Strangomera bentincki), and jack mackerel ( Trachurus murphyi) in central-southern Chile. Twelve environmental variables were considered along with fishing effort (fe) and landing statistics from 1973 to 2012. During external validation, the best models with all of the selected variables gave r 2 values of 90 % for anchovy, 96 % for common sardine, and 88 % for jack mackerel. The models were simplified by considering only fe and sea surface temperature from NCEP/NCAR reanalysis data (SST-NOAA), and very similar fits were achieved (87, 92, and 88 %, respectively). Future SSTs were obtained from the A2 climate change scenario and regionalized using statistical downscaling techniques. The downscaled SSTs were used as input for landings predictions using ANN simplified models. In addition, three scenarios of future fishing efforts (2010-2012 average, average + 50 %, and average - 50 %) were used as the input data for landing simulations. The results of the predictions show a decrease of 9 % in future landings of sardine and an increase of 17 % for jack mackerel when comparing 2015 and 2065 monthly projections. However, no significant differences are shown when comparing the estimated landings for the three fishing effort scenarios. Finally, more integrative and complex conceptual models that consider oceanographic-biophysical, physiological, environmental-resource, and interspecies processes need to be implemented.

  14. Analyzing Food-Related Life Satisfaction and other Predictors of Life Satisfaction in Central Chile.

    PubMed

    Schnettler, Berta; Lobos, Germán; Orellana, Ligia; Grunert, Klaus; Sepúlveda, José; Mora, Marcos; Denegri, Marianela; Miranda, Horacio

    2015-06-17

    This study aimed to assess the effect of satisfaction with food-related life on life satisfaction among inhabitants of the main municipalities of central Chile. A survey was applied to a sample of 1,277 people, distributed proportionally by municipality. The questionnaire included the following scales: SWLS (Satisfaction with Life Scale), SWFL (Satisfaction with Food-related Life) and the Health-Related Quality of Life Index (HRQOL). Questions were asked regarding eating habits inside and outside the home, time available for meals at home, the assessment of five sources of happiness and the demographic characteristics of those surveyed. An ordered logit model was proposed, in which the dependent variable was satisfaction with life. Satisfaction with life was significantly related to the respondent's socioeconomic status, self-perception of health, degree of satisfaction with food-related life, monthly food expenditure, time available for supper with the family (p < .01); gender, self-reported number of days affected by mental health problems, frequency of supper with the family, the degree of agreement with respect to family being an important source of happiness (p < .05); and family size and frequency of food consumption in fast food outlets (p < .10). Satisfaction with life in the study sample is related to aspects associated with health, family and eating, and the family interaction associated with eating may play an important role in overall satisfaction with life.

  15. Vertical distribution of rocky subtidal assemblages along the exposed coast of north-central Chile

    NASA Astrophysics Data System (ADS)

    Stotz, Wolfgang B.; Aburto, Jaime; Caillaux, Luis M.; González, Sergio A.

    2016-01-01

    Through a systematic study of a stretch of coast in north central Chile, the variety and vertical zonation patterns of the rocky subtidal communities are described, thereby revising apparent uniformity and lack of vertical zonation of the rocky subtidal of southeastern Pacific shores previously reported in the literature. Over the 600 km of coast studied, the following pattern of depth-zonation is described: an upper fringe (lower part of the sublittoral fringe) characterized by barren grounds dominated by calcareous encrusting algae and the sea urchin Tetrapygus niger; an intermediate fringe (upper Infralittoral sub-zone) characterized either by deep barren grounds similar to the former, or kelp beds of Lessonia trabeculata, or an assemblage of suspension feeding organisms, as the big barnacle Austromegabalanus psittacus and/or the tunicate Pyura chilensis; and a deep fringe (Circalittoral sub-zone) dominated by small encrusting or mobile invertebrates. This basic vertical zonation pattern of the shallow rocky subtidal communities seems to be common to most of the temperate coasts of the world. The analysis, first of the occurrence of the general zonation pattern and second of the species composition within the assemblages corresponding to each sub-zone, offers a useful framework for the assessment of the eventual impacts and changes within the shallow rocky subtidal habitat, for example within environmental monitoring programs.

  16. Effects of maize cultivation on nitrogen and phosphorus loadings to drainage channels in Central Chile.

    PubMed

    Corradini, Fabio; Nájera, Francisco; Casanova, Manuel; Tapia, Yasna; Singh, Ranvir; do Salazar, Osval

    2015-11-01

    There are concerns about the impact of maize cultivation with high applications of nitrogen (N) and phosphorus (P) on water quality in surface waters in Mediterranean Central Chile. This study estimated the contribution of N and P from maize fields to nearby drainage channels and evaluated the effects in water quality. An N and P budget was drawn up for three fields managed with a maize-fallow system, El Maitén (20.7 ha), El Naranjal (14.9 ha) and El Caleuche (4.2 ha), and water quality variables (pH, EC, dissolved oxygen, total solids, turbidity, NO3-N, NH4-N, PO4(3-), COD, total N, total P and sulphate) were monitored in nearby drainage channels. The N and P balances for the three fields indicated a high risk of N and P non-point source pollution, with fertiliser management, soil texture and climate factors determining the temporal variations in water quality parameters. Elevated levels of NH4-N and PO4(3-) in the drainage channels were usually observed during the winter period, while NO3- concentrations did not show a clear tendency. The results suggest that excessive slurry application during winter represents a very high risk of N and P runoff to drainage channels. Overall, great emphasis must be placed on good agronomic management of fields neighbouring drainage channels, including accurately calculating N and P fertiliser rates and establishing mitigation measures.

  17. Marine protected areas facilitate parasite populations among four fished host species of central Chile.

    PubMed

    Wood, Chelsea L; Micheli, Fiorenza; Fernández, Miriam; Gelcich, Stefan; Castilla, Juan Carlos; Carvajal, Juan

    2013-11-01

    1. Parasites comprise a substantial proportion of global biodiversity and exert important ecological influences on hosts, communities and ecosystems, but our knowledge of how parasite populations respond to human impacts is in its infancy. 2. Here, we present the results of a natural experiment in which we used a system of highly successful marine protected areas and matched open-access areas in central Chile to assess the influence of fishing-driven biodiversity loss on parasites of exploited fish and invertebrate hosts. We measured the burden of gill parasites for two reef fishes (Cheilodactylus variegatus and Aplodactylus punctatus), trematode parasites for a keyhole limpet (Fissurella latimarginata), and pinnotherid pea crab parasites for a sea urchin (Loxechinus albus). We also measured host density for all four hosts. 3. We found that nearly all parasite species exhibited substantially greater density (# parasites m(-2)) in protected than in open-access areas, but only one parasite species (a gill monogenean of C. variegatus) was more abundant within hosts collected from protected relative to open-access areas. 4. These data indicate that fishing can drive declines in parasite abundance at the parasite population level by reducing the availability of habitat and resources for parasites, but less commonly affects the abundance of parasites at the infrapopulation level (within individual hosts). 5. Considering the substantial ecological role that many parasites play in marine communities, fishing and other human impacts could exert cryptic but important effects on marine community structure and ecosystem functioning via reductions in parasite abundance.

  18. Effects of maize cultivation on nitrogen and phosphorus loadings to drainage channels in Central Chile.

    PubMed

    Corradini, Fabio; Nájera, Francisco; Casanova, Manuel; Tapia, Yasna; Singh, Ranvir; do Salazar, Osval

    2015-11-01

    There are concerns about the impact of maize cultivation with high applications of nitrogen (N) and phosphorus (P) on water quality in surface waters in Mediterranean Central Chile. This study estimated the contribution of N and P from maize fields to nearby drainage channels and evaluated the effects in water quality. An N and P budget was drawn up for three fields managed with a maize-fallow system, El Maitén (20.7 ha), El Naranjal (14.9 ha) and El Caleuche (4.2 ha), and water quality variables (pH, EC, dissolved oxygen, total solids, turbidity, NO3-N, NH4-N, PO4(3-), COD, total N, total P and sulphate) were monitored in nearby drainage channels. The N and P balances for the three fields indicated a high risk of N and P non-point source pollution, with fertiliser management, soil texture and climate factors determining the temporal variations in water quality parameters. Elevated levels of NH4-N and PO4(3-) in the drainage channels were usually observed during the winter period, while NO3- concentrations did not show a clear tendency. The results suggest that excessive slurry application during winter represents a very high risk of N and P runoff to drainage channels. Overall, great emphasis must be placed on good agronomic management of fields neighbouring drainage channels, including accurately calculating N and P fertiliser rates and establishing mitigation measures. PMID:26490735

  19. Holocene coseismic and aseismic uplift of Isla Mocha, south-central Chile

    USGS Publications Warehouse

    Nelson, A.R.; Manley, W.F.

    1992-01-01

    During the past 6000 years Isla Mocha, a 12 km-long island 30 km off the coast of south-central Chile, experienced a 38 m fall of relative sea level caused primarily by rapid tectonic uplift of the island. As many as 18 raised shorelines (strandlines) record this uplift. Historic accounts of uplift during the great earthquakes (M > 8) of 1835 and 1960 suggest some of the more prominent prehistoric strandlines also emerged during great earthquakes on the interface between the Nazca and South America plates. But the close elevational spacing of strandlines, subdued morphology of strandline beaches, scarcity of exposed bedrock wave-cut platforms, and the extremely high rates of aseismic uplift (ca. 70 mm/yr) of the island since the last great earthquake suggest that many strandlines were raised by aseismic rather than coseismic uplift. Strandline heights and 14 new radiocarbon ages on marine shells show that the present-day uplift rate is more than three times the net rate (ca. 20 mm/yr) of the past 1000 years. The recent high rate probably reflects increased aseismic slip on an inferred thrust fault in the overriding South America plate. Isla Mocha overlies an area of high stress concentration between two major segments of the Chilean subduction zone. The inferred high rate of slip on the thrust fault may be a response to stress changes on the plate interface near the boundary between the segments. ?? 1992.

  20. Abiotic ammonification and gross ammonium photoproduction in the upwelling system off central Chile (36° S)

    NASA Astrophysics Data System (ADS)

    Rain-Franco, A.; Muñoz, C.; Fernandez, C.

    2012-12-01

    We investigated the production of ammonium via photodegradation of dissolved organic matter (DOM) in the coastal upwelling system off central Chile (36° S). Photoammonification experiments were carried out using exudates obtained from representative diatom species (Chaetoceros muelleri and Thalassiosira minuscule) and natural marine DOM under simulated solar radiation conditions. Additionally, we evaluated the use of photoproduced ammonium by natural microbial communities and separated ammonium oxidizing archaea and bacteria by using GC-7 as an inhibitor of the archaeal community. We found photoammonification operating at two levels: via the transformation of DOM by UV radiation (abiotic ammonification) and via the simultaneous occurrence of abiotic phototransformation and biological remineralization of DOM into NH4+ (referred as gross photoproduction of NH4+). The maximum rates of abiotic ammonification reached 0.057 μmol L-1 h-1, whereas maximum rates of gross photoproduction reached 0.746 μmol L-1 h-1. Our results also suggest that ammonium oxidizing archaea could dominate the biotic remineralization induced by photodegradation of organic matter and consequently play an important role in the local N cycle. Abiotic ammonium photoproduction in coastal upwelling systems could support between 7 and 50% of the spring-summer phytoplankton NH4+ demand. Surprisingly, gross ammonium photoproduction (remineralization induced by abiotic ammonification) might support 50 to 180% of spring-summer phytoplankton NH4+ assimilation.

  1. Analyzing Food-Related Life Satisfaction and other Predictors of Life Satisfaction in Central Chile.

    PubMed

    Schnettler, Berta; Lobos, Germán; Orellana, Ligia; Grunert, Klaus; Sepúlveda, José; Mora, Marcos; Denegri, Marianela; Miranda, Horacio

    2015-01-01

    This study aimed to assess the effect of satisfaction with food-related life on life satisfaction among inhabitants of the main municipalities of central Chile. A survey was applied to a sample of 1,277 people, distributed proportionally by municipality. The questionnaire included the following scales: SWLS (Satisfaction with Life Scale), SWFL (Satisfaction with Food-related Life) and the Health-Related Quality of Life Index (HRQOL). Questions were asked regarding eating habits inside and outside the home, time available for meals at home, the assessment of five sources of happiness and the demographic characteristics of those surveyed. An ordered logit model was proposed, in which the dependent variable was satisfaction with life. Satisfaction with life was significantly related to the respondent's socioeconomic status, self-perception of health, degree of satisfaction with food-related life, monthly food expenditure, time available for supper with the family (p < .01); gender, self-reported number of days affected by mental health problems, frequency of supper with the family, the degree of agreement with respect to family being an important source of happiness (p < .05); and family size and frequency of food consumption in fast food outlets (p < .10). Satisfaction with life in the study sample is related to aspects associated with health, family and eating, and the family interaction associated with eating may play an important role in overall satisfaction with life. PMID:26083311

  2. Landsat image and sample design for water reservoirs (Rapel dam Central Chile).

    PubMed

    Lavanderos, L; Pozo, M E; Pattillo, C; Miranda, H

    1990-01-01

    Spatial heterogeneity of the Rapel reservoir surface waters is analyzed through Landsat images. The image digital counts are used with the aim or developing an aprioristic quantitative sample design.Natural horizontal stratification of the Rapel Reservoir (Central Chile) is produced mainly by suspended solids. The spatial heterogeneity conditions of the reservoir for the Spring 86-Summer 87 period were determined by qualitative analysis and image processing of the MSS Landsat, bands 1 and 3. The space-time variations of the different observed strata obtained with multitemporal image analysis.A random stratified sample design (r.s.s.d) was developed, based on the digital counts statistical analysis. Strata population size as well as the average, variance and sampling size of the digital counts were obtained by the r.s.s.d method.Stratification determined by analysis of satellite images were later correlated with ground data. Though the stratification of the reservoir is constant over time, the shape and size of the strata varys. PMID:24243254

  3. A new species of Pomphorhynchus (Acanthocephala: Palaeacanthocephala) in freshwater fishes from central Chile.

    PubMed

    Olmos, Viviana L; Habit, Evelyn M

    2007-02-01

    This study describes a new species of Pomphorhynchus collected from Percilia gillissi Girard, 1855 from the Zañartu canal, between the sister basins of the Itata and Laja rivers, in central Chile. Pomphorhynchus moyanoi n. sp. is characterized by an asymmetrical, well-differentiated subspherical bulb and 12-14 longitudinal rows of 13-14 hooks; the third and the fourth hook in each row are stout. Among South American species, P. moyanoi n. sp. shows some similarities to the Chilean species P. yamagutii Schmidt & Hugghins, 1973, but it differs in having a longer neck, larger bulb, and different proboscis armature arrangement. Pomphorhynchus moyanoi n. sp. differs from P. patagonicus Ortubay, Ubeda, Semenas & Kennedy 1991, in the bulb shape (protuberances), number of rows, fourth hook size and basal hook size. Pomphorhynchus moyanoi n. sp. also differs from P. sphaericus in the arrangement of hooks (number of rows and hooks per row), length and width of the proboscis, neck width, and symmetry of the bulb.

  4. Assessing environmental drivers of microbial communities in estuarine soils of the Aconcagua River in Central Chile.

    PubMed

    Fuentes, Sebastián; Ding, Guo-Chun; Cárdenas, Franco; Smalla, Kornelia; Seeger, Michael

    2015-10-01

    Aconcagua River basin (Central Chile) harbors diverse economic activities such as agriculture, mining and a crude oil refinery. The aim of this study was to assess environmental drivers of microbial communities in Aconcagua River estuarine soils, which may be influenced by anthropogenic activities taking place upstream and by natural processes such as tides and flood runoffs. Physicochemical parameters were measured in floodplain soils along the estuary. Bacteria, Actinobacteria, Alphaproteobacteria, Betaproteobacteria, Pseudomonas, Bacillus and Fungi were studied by DGGE fingerprinting of 16S rRNA gene and ribosomal ITS-1 amplified from community DNA. Correlations between environment and communities were assessed by distance-based redundancy analysis. Mainly hydrocarbons, pH and the composed variable copper/arsenic/calcium but in less extent nitrogen and organic matter/phosphorous/magnesium correlated with community structures at different taxonomic levels. Aromatic hydrocarbons degradation potential by bacterial community was studied. Polycyclic aromatic hydrocarbon ring-hydroxylating dioxygenases genes were detected only at upstream sites. Naphthalene dioxygenase ndo genes were heterogeneously distributed along estuary, and related to Pseudomonas, Delftia, Comamonas and Ralstonia. IncP-1 plasmids were mainly present at downstream sites, whereas IncP-7 and IncP-9 plasmids showed a heterogeneous distribution. This study strongly suggests that pH, copper, arsenic and hydrocarbons are main drivers of microbial communities in Aconcagua River estuarine soils.

  5. Growth of the Humboldt Current krill in the upwelling zone off central Chile

    NASA Astrophysics Data System (ADS)

    Riquelme-Bugueño, Ramiro; Silva-Aburto, Jocelyn; Escribano, Rubén; Peterson, William T.; Schneider, Wolfgang

    2016-11-01

    Temporal variability in the daily growth rate (DGR) of the Humboldt Current krill, Euphausia mucronata, was studied in eighteen incubation experiments off the coast of Dichato, central Chile (36.5°S), carried out in 2011-2014. Intermolt period (IMP) was derived from the molting rate method in order to estimate the DGRs. Mean IMP was 9.2 ± 4.8 days (range: 2.9-18.7 d). Overall mean DGR was 0.03 ± 0.13 mm d- 1. DGR showed a dome-shaped pattern, with a higher mean DGR when upwelling was moderate (0.06 ± 0.04 mm d- 1) than intense (0.01 ± 0.00 mm d- 1) or weak (0.01 ± - 0.01 mm d- 1). This dome-shaped trend was observed in chlorophyll-a concentrations (Chla) at similar upwelling regimens. E. mucronata DGR variability was best explained by a generalized linear model which included the contribution of the Equatorial Subsurface Water, temperature, dissolved oxygen and Chla as predictor variables. Results suggest that E. mucronata is better adapted to grow under upwelling conditions when it can take advantage of high biological productivity, although the species growth is not limited when weak upwelling or even downwelling occurs. Analysis of the duration of the upwelling events suggest that E. mucronata growth is limited (shrinking) when upwellings last > 10 days.

  6. Assessing environmental drivers of microbial communities in estuarine soils of the Aconcagua River in Central Chile.

    PubMed

    Fuentes, Sebastián; Ding, Guo-Chun; Cárdenas, Franco; Smalla, Kornelia; Seeger, Michael

    2015-10-01

    Aconcagua River basin (Central Chile) harbors diverse economic activities such as agriculture, mining and a crude oil refinery. The aim of this study was to assess environmental drivers of microbial communities in Aconcagua River estuarine soils, which may be influenced by anthropogenic activities taking place upstream and by natural processes such as tides and flood runoffs. Physicochemical parameters were measured in floodplain soils along the estuary. Bacteria, Actinobacteria, Alphaproteobacteria, Betaproteobacteria, Pseudomonas, Bacillus and Fungi were studied by DGGE fingerprinting of 16S rRNA gene and ribosomal ITS-1 amplified from community DNA. Correlations between environment and communities were assessed by distance-based redundancy analysis. Mainly hydrocarbons, pH and the composed variable copper/arsenic/calcium but in less extent nitrogen and organic matter/phosphorous/magnesium correlated with community structures at different taxonomic levels. Aromatic hydrocarbons degradation potential by bacterial community was studied. Polycyclic aromatic hydrocarbon ring-hydroxylating dioxygenases genes were detected only at upstream sites. Naphthalene dioxygenase ndo genes were heterogeneously distributed along estuary, and related to Pseudomonas, Delftia, Comamonas and Ralstonia. IncP-1 plasmids were mainly present at downstream sites, whereas IncP-7 and IncP-9 plasmids showed a heterogeneous distribution. This study strongly suggests that pH, copper, arsenic and hydrocarbons are main drivers of microbial communities in Aconcagua River estuarine soils. PMID:26362923

  7. Paleoenvironmental change in central Chile as inferred from OSL dating of ancient coastal sand dunes

    NASA Astrophysics Data System (ADS)

    Andrade, Belisario; Garcia, Juan L.; Lüthgens, Christopher; Fiebig, Markus

    2013-04-01

    To present day, the climatic and geographic expression of glacials and interglacials in the semiarid coast of central Chile remains unclear. The lack of well dated paleoclimatic records has up to now precluded firm conclusions whether maximum glacials evident in the Andes mountain range probably coincide with wetter (e.g., pluvials) or drier conditions at the coast. The natural region locally known as "Norte Chico" represents a transitional semiarid area between the extreme Atacama Desert to the North and the wetter, Mediterranean-like type of climate, to the South. In this semiarid region of Chile several generations of eolian sand dunes, some of them separated by paleosoils, have been preserved. In addition to the occurrence of paleosoils, thick debris flow deposits in some places overly ancient dune bodies, likely indicating significant environmental changes during the formation of these archives. However, the exact timing of these processes within the mid to late Pleistocene and Holocene is still unclear. A key aspect is that some of the ancient dunes are recently hanging above rocky coastlines, where no supply of sand exists today, likely implying their formation during a lower than present, probably glacio-eustatically induced sea level. The location of the research area in a key mid-latitude region of the eastern Pacific in combination with the preserved landform record offers a chance to reconstruct climatic shifts during the Quaternary by studying the variability of morphogenetic conditions throughout time, in order to promote knowledge about possible forcing factors driving climatic variability. Within this pilot study, samples for optically stimulated luminescence (OSL) dating were taken from three different stratigraphic sections that denote a complex environmental variability as indicated by paleosoils and debris flow units intercalated in ancient sand dunes. First dating results inferred from OSL measurements using a post-IR IRSL (pIRIR) protocol for

  8. Structural control of the emplacement of the Portrerillos porphyry copper, central Andes of Chile

    NASA Astrophysics Data System (ADS)

    Niemeyer, Hans; Munizaga, Rodrigo

    2008-11-01

    The Potrerillos porphyry is located in the Late Eocene-Oligocene metallogenic belt of porphyry copper deposits of Chile, Cordillera de Domeyko, central Andes. It is formed of a porphyritic biotite-hornblende monzonite that was emplaced at less than 1000 m depth. The intrusion has a cylindrical vertical form at depth, whereas its uppermost section resembles a mushroom whose stem is inclined 20-25° to the northwest. The location of the Potrerillos porphyry coincides with a major facies and east-west thickness change in Jurassic to Late Cretaceous marine sedimentary and Tertiary volcanic host rocks. Structurally, the porphyry was emplaced at the intersection between the northeast-oriented Potrerillos fold-and-thrust belt, and a system of northwest-trending strike-slip faults of the Ciénaga fault system. Both structural elements are related to a sinistral regional transpression that was active during the Middle to Late Eocene. The north-northeast trending Sierra Castillo-Agua Amarga fault system was trench-linked with an oblique subduction along the Peru-Chile trench in the southwestern part of South America at this time. One of the main structural elements of the Potrerillos fold-and-thrust belt is the eastward verging Potrerillos Mine reverse fault. We demonstrate a syntectonic relationship between the Potrerillos porphyry emplacement and the onset of the Potrerillos Mine fault. The control at the shallowest levels of the Potrerillos porphyry emplacement was studied by means of a structural analysis of folds, cleavage and deformed oolites in the country rock. This analysis suggests that the porphyry occupied the core of an anticline. The form of this anticline was modeled as a fault-propagation-fold taking into account a 200 m displacement along the basal fault and a local shortening of 45.5% occurred. This model is compatible with a limited displacement along the Potrerillos Mine fault under hot, ductile conditions. The remaining displacement of 1600 m would have

  9. Cosmogenic Nuclide Studies And Geomorphological Implications In The Hyperarid Central Western Andes, Northern Chile

    NASA Astrophysics Data System (ADS)

    Kober, F.; Schlunegger, F.; Ivy-Ochs, S.; Baur, H.; Wieler, R.; Kubik, P. W.; Schneider, H.

    2003-12-01

    We have conducted geomorphological and cosmogenic nuclide studies in the central Andes of Northern Chile (Arica area) in order to quantify landscape evolution at the Western Andean Escarpment. The area is characterized by broad abandoned middle to late Miocene plains that are cut by deeply incised rivers. The major phase of incision has been active since ca. 8 My with different magnitudes and accelerated backward erosion forces through time. Important processes must have been a base level change in the Coastal Cordillera area and climatic changes driven by orogenic growth. Fluvial incision rates are ca. 50m/My across the Escarpment during the middle/late Miocene and early Pliocene and about two to four times higher from the Pliocene until the present, especially in more distal parts relative to the pinned base level control (enhanced backward erosion). Bedrock erosion rates on the broad plains determined with cosmogenic nuclides are several orders of magnitude lower than fluvial incision rates. Erosion rates of ignimbrites determined by paired studies of radionuclides (10Be, 26Al) and stable 21Ne are 10 to 100cm/My at medium elevations and increase towards the high Andes to >250cm/My. This increase is largely controlled by the effect of orographic precipitation that correlates with increasing rates and intensities of rainfall towards the Western Cordillera. Coastal areas, subjected only to coastal fog, show abandoned hanging rivers and smoothed diffusive hillslopes. These landscapes exhibit also extremely low cosmogenically derived erosion rates (<100cm/My). Therefore, the large parts of the landscapes at the northern tip of the Atacama Desert have retained their relict landscape aspect since they formed in Middle Micocene. The comparison of river incision and bedrock erosion clearly shows a strong decoupling between both geomorphic landscape units. A change towards a coupled system can only be found in the high, rainy parts of the Andes (>3500m), which are

  10. A Centralized Auction Mechanism for the Disability and Survivors Insurance in Chile

    NASA Astrophysics Data System (ADS)

    Reyes H., Gonzalo

    As part of the pension reform recently approved in Chile, the government introduced a centralized auction mechanism to provide the Disability and Survivors (D&S) Insurance that covers recent contributors among the more than 8 million participants in the mandatory private pension system. This paper is intended as a case study presenting the main distortions found in the decentralized operation of the system that led to this reform and the challenges faced when designing a competitive auction mechanism to be implemented jointly by the Pension Fund Managers (AFP). In a typical bilateral contract the AFP retained much of the risk and the Insurance Company acted in practice as a reinsurer. The process to hire this contract was not competitive and colligated companies ended up providing the service. Several distortions affected competition in the market through incentives to cream-skim members by AFPs (since they bear most of the risk) or efforts to block disability claims. Since the price of this insurance is hidden in the fees charged by AFPs for the administration of individual accounts and pension funds there was lack of price transparency. Since new AFPs have no history of members’ disability and mortality profile the insurance contract acted as a barrier to entry in the market of AFP services, especially when D&S insurance costs reached 50% of total costs. Cross-subsidies between members of the same AFP, inefficient risk pooling (due to pooling occurring at the AFP rather than at the system level) and regulatory arbitrage, since AFPs provided insurance not being regulated as an insurance company, were also present. A centralized auction mechanism solves these market failures, but also gives raise to new challenges, such as how to design a competitive auction that attracts participation and deters collusion. Design features that were incorporated in the regulation to tackle these issues, such as dividing coverage into predefined percentage blocks, are presented

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

    NASA Astrophysics Data System (ADS)

    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

  12. Coseismic gravity changes of the 2010 earthquake in Central Chile from satellite gravimetry

    NASA Astrophysics Data System (ADS)

    Heki, K.; Matsuo, K.

    2010-12-01

    as the replacement of air with crustal rock), we modified it so that a smaller density contrast (between crustal rock and sea water) is assumed for vertical deformation of sea floor. After applying the same fan filter, the calculated gravity changes was quite similar to those observed by GRACE. The 2004 SA Earthquake showed distinct postseismic gravity changes (with a time constant of ~0.6 year) characterized by slow increase above the focal area. Past interpretations include the flow of supercritical water around the down-dip end of the fault, Burgers rheology of the low viscosity material in shallow mantle, and afterslip in the down-dip and up-dip extension of the main rupture. Postseismic crustal deformations have been observed with GPS numerous times. In contrast, postseismic gravity changes have been observed just once for the 2004 SA event, and its mechanism has not been well understood. We still have only a few months of GRACE data after the earthquake, too short to separate postseismic and hydrological gravity changes. It is important and interesting to keep investigating slow gravity changes in Central Chile over a long term.

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

    NASA Astrophysics Data System (ADS)

    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

  14. Antibacterial Activity, Antioxidant Effect and Chemical Composition of Propolis from the Región del Maule, Central Chile.

    PubMed

    Nina, Nélida; Quispe, Cristina; Jiménez-Aspee, Felipe; Theoduloz, Cristina; Feresín, Gabriela Egly; Lima, Beatriz; Leiva, Elba; Schmeda-Hirschmann, Guillermo

    2015-01-01

    Propolis is commercialized in Chile as an antimicrobial agent. It is obtained mainly from central and southern Chile, but is used for the same purposes regardless of its origin. To compare the antimicrobial effect, the total phenolic (TP), the total flavonoid (TF) content and the phenolic composition, 19 samples were collected in the main production centers in the Región del Maule, Chile. Samples were extracted with MeOH and assessed for antimicrobial activity against Gram (+) and Gram (-) bacteria. TP and TF content, antioxidant activity by the DPPH, FRAP and TEAC methods were also determined. Sample composition was assessed by HPLD-DAD-ESI-MS/MS. Differential compounds in the samples were isolated and characterized. The antimicrobial effect of the samples showed MICs ranging from 31.5 to > 1000 µg/mL. Propolis from the central valley was more effective as antibacterial than those from the coastal area or Andean slopes. The samples considered of interest (MIC ≤ 62.5 µg/mL) showed effect on Escherichia coli, Pseudomonas sp., Yersinia enterocolitica and Salmonella enteritidis. Two new diarylheptanoids, a diterpene, the flavonoids pinocembrin and chrysin were isolated and elucidated by spectroscopic and spectrometric means. Some 29 compounds were dereplicated by HPLC-MS and tentatively identified, including nine flavones/flavonol derivatives, one flavanone, eight dihydroflavonols and nine phenyl-propanoids. Propolis from the Región del Maule showed large variation in antimicrobial effect, antioxidant activity and composition. So far the presence of diarylheptanoids in samples from the coastal area of central Chile can be considered as a marker of a new type of propolis. PMID:26457694

  15. Antibacterial Activity, Antioxidant Effect and Chemical Composition of Propolis from the Región del Maule, Central Chile.

    PubMed

    Nina, Nélida; Quispe, Cristina; Jiménez-Aspee, Felipe; Theoduloz, Cristina; Feresín, Gabriela Egly; Lima, Beatriz; Leiva, Elba; Schmeda-Hirschmann, Guillermo

    2015-10-06

    Propolis is commercialized in Chile as an antimicrobial agent. It is obtained mainly from central and southern Chile, but is used for the same purposes regardless of its origin. To compare the antimicrobial effect, the total phenolic (TP), the total flavonoid (TF) content and the phenolic composition, 19 samples were collected in the main production centers in the Región del Maule, Chile. Samples were extracted with MeOH and assessed for antimicrobial activity against Gram (+) and Gram (-) bacteria. TP and TF content, antioxidant activity by the DPPH, FRAP and TEAC methods were also determined. Sample composition was assessed by HPLD-DAD-ESI-MS/MS. Differential compounds in the samples were isolated and characterized. The antimicrobial effect of the samples showed MICs ranging from 31.5 to > 1000 µg/mL. Propolis from the central valley was more effective as antibacterial than those from the coastal area or Andean slopes. The samples considered of interest (MIC ≤ 62.5 µg/mL) showed effect on Escherichia coli, Pseudomonas sp., Yersinia enterocolitica and Salmonella enteritidis. Two new diarylheptanoids, a diterpene, the flavonoids pinocembrin and chrysin were isolated and elucidated by spectroscopic and spectrometric means. Some 29 compounds were dereplicated by HPLC-MS and tentatively identified, including nine flavones/flavonol derivatives, one flavanone, eight dihydroflavonols and nine phenyl-propanoids. Propolis from the Región del Maule showed large variation in antimicrobial effect, antioxidant activity and composition. So far the presence of diarylheptanoids in samples from the coastal area of central Chile can be considered as a marker of a new type of propolis.

  16. A new species of Liolaemus related to L. nigroviridis from the Andean highlands of Central Chile (Iguania, Liolaemidae)

    PubMed Central

    Troncoso-Palacios, Jaime; Elorza, Alvaro A.; Puas, German I.; Alfaro-Pardo, Edmundo

    2016-01-01

    Abstract The Liolaemus nigroviridis group is a clade of highland lizards endemic to Chile. These species are distributed from northern to central Chile, and currently there are no cases of sympatric distribution. This study describes a new species, Liolaemus uniformis sp. n., from this group, and provides a detailed morphological characterization and mitochondrial phylogeny using cytochrome-b. Liolaemus uniformis was found in sympatry with Liolaemus nigroviridis but noticeably differed in size, scalation, and markedly in the color pattern, without sexual dichromatism. This new species has probably been confused with Liolaemus monticola and Liolaemus bellii, both of which do not belong to the nigroviridis group. The taxonomic issues of this group that remain uncertain are also discussed. PMID:26877688

  17. A new species of Liolaemus related to L. nigroviridis from the Andean highlands of Central Chile (Iguania, Liolaemidae).

    PubMed

    Troncoso-Palacios, Jaime; Elorza, Alvaro A; Puas, German I; Alfaro-Pardo, Edmundo

    2016-01-01

    The Liolaemus nigroviridis group is a clade of highland lizards endemic to Chile. These species are distributed from northern to central Chile, and currently there are no cases of sympatric distribution. This study describes a new species, Liolaemus uniformis sp. n., from this group, and provides a detailed morphological characterization and mitochondrial phylogeny using cytochrome-b. Liolaemus uniformis was found in sympatry with Liolaemus nigroviridis but noticeably differed in size, scalation, and markedly in the color pattern, without sexual dichromatism. This new species has probably been confused with Liolaemus monticola and Liolaemus bellii, both of which do not belong to the nigroviridis group. The taxonomic issues of this group that remain uncertain are also discussed. PMID:26877688

  18. Monitoring and Modelling Glacier Melt and Runoff on Juncal Norte Glacier, Aconcagua River Basin, Central Chile

    NASA Astrophysics Data System (ADS)

    Pellicciotti, F.; Helbing, J. F.; Araos, J.; Favier, V.; Rivera, A.; Corripio, J.; Sicart, J. M.

    2006-12-01

    Results from a recent glacio-meteorological experiment on the Juncal Norte glacier, in central Chile, are presented. Melt water is a crucial resource in the Central Andes, as it provides drinking water, water for agriculture and for industrial uses. There is also increasing competition for water use and allocation, as water demands from mining and industry are rising. Assessing water availability in this region and its relation with climatic variations is therefore crucial. The Dry Central Andes are characterised by a climatic setting different from that of the Alps and the subtropical Andes of Bolivia and Peru. Summers are very dry and stable, with precipitation close to zero and low relative humidity. Solar radiation is very intense, and plays a key role in the energy balance of snow covers and glaciers. The main aim of this study is to investigate the glacier-climate interaction in this area, with particular attention devoted to advanced modelling techniques for the spatial redistribution of meteorological variables, in order to gain an accurate picture of the ablation processes typical of these latitudes. During the ablation season 2005/2006, an extensive field campaign was conducted on the Juncal Norte glacier, aimed at monitoring the melt and runoff generation processes on this remote glacier in the dry Andes. Melt rates, runoff at the snout, meteorological variables over and near the glacier, GPS data and glacier topography were recorded over the entire ablation season. Using this extensive and accurate data set, the spatial and temporal variability of the meteorological variables that drive the melt process on the glacier is investigated, together with the process of runoff generation. An energy balance model is used to simulate melt across the glacier, and special attention is devoted to the modelling of the solar radiation energy flux. The components of the energy balance are compared with those of Alpine basins. The validity of parameterisations of the

  19. Paleozoic evolution of active margin basins in the southern Central Andes (northwestern Argentina and northern Chile)

    NASA Astrophysics Data System (ADS)

    Bahlburg, H.; Breitkreuz, C.

    The geodynamic evolution of the Paleozoic continental margin of Gondwana in the region of the southern Central Andes is characterized by the westward progression of orogenic basin formation through time. The Ordovician basin in the northwest Argentinian Cordillera Oriental and Puna originated as an Early Ordovician back-arc basin. The contemporaneous magmatic arc of an east-dipping subduction zone was presumably located in northern Chile. In the back-arc basin, a ca. 3500 meter, fining-up volcaniclastic apron connected to the arc formed during the Arenigian. Increased subsidence in the late Arenigian allowed for the accomodation of large volumes of volcaniclastic turbidites during the Middle Ordovician. Subsidence and sedimentation were caused by the onset of collision between the para-autochthonous Arequipa Massif Terrane (AMT) and the South American margin at the Arenigian-Llanvirnian transition. This led to eastward thrusting of the arc complex over its back-arc basin and, consequently, to its transformation into a marine foreland basin. As a result of thrusting in the west, a flexural bulge formed in the east, leading to uplift and emergence of the Cordillera Oriental shelf during the Guandacol Event at the Arenigian-Llanvirnian transition. The basin fill was folded during the terminal collision of the AMT during the Oclóyic Orogeny (Ashgillian). The folded strata were intruded post-tectonically by the presumably Silurian granitoids of the "Faja Eruptiva de la Puna Oriental." The orogeny led to the formation of the positive area of the Arco Puneño. West of the Arco Puneño, a further marine basin developed during the Early Devonian, the eastern shelf of which occupied the area of the Cordillera Occidental, Depresión Preandina, and Precordillera. The corresponding deep marine turbidite basin was located in the region of the Cordillera de la Costa. Deposition continued until the basin fill was folded in the early Late Carboniferous Toco Orogeny. The basin

  20. Climate change adaptation in a highly urbanized snowmelt dominated basin in Central Chile

    NASA Astrophysics Data System (ADS)

    Vicuna, S.; Bustos, E.; Merino, P.; Henriquez Dole, L. E.; Jansen, S.; Gil, M.; Ocampo, A.; Poblete, D.; Tosoni, D.; Meza, F. J.; Donoso, G.; Melo, O.

    2015-12-01

    The Maipo river basin holds 40% of Chile's total population and produces almost half of the country's Gross Domestic Product. The basin is located in the semiarid and snowmelt dominated central region of the country and, aside from the typical pressures of growth in developing country basins, the Maipo river basin faces climate change impacts associated with a reduction in total runoff and changes in its seasonality. Surface water is the main water source for human settlements, natural ecosystems, and economic activities including agriculture, mining and hydropower production. In 2012 a research project, called MAPA (Maipo Plan de Adaptacion), began with the objective of articulating a climate variability and climate change adaptation plan for the Maipo river basin. The project engaged at the beginning a group of relevant water and land use stakeholders which allowed for a good representation of critical aspects of an adaptation plan such as the definition of objectives and performance indicators, future land use scenarios, modeling of the different components of the system and design of adaptation strategies. The presentation will highlight the main results of the research project with a special focus on the upper catchments of the basin. These results include the assessment of impacts associated with future climate and land use scenarios on key components of the hydrologic cycle including snowmelt and glacier contribution to runoff and subsequent impacts on water availability for the operation of hydropower facilities, satisfaction of instream (recreation and aquatic ecosystem) uses and provision of water for the city of Santiago (7 million people) and to irrigate more than 100,000 hectares of high value crops. The integrative approach followed in this project including different perspectives on the use of water in the basin provides a good opportunity to test the varying degree of impacts that could be associated with a given future scenario and also understand

  1. Analysis of Future Streamflow Regimes under Global Change Scenarios in Central Chile for Ecosystem Sustainability

    NASA Astrophysics Data System (ADS)

    Henriquez Dole, L. E.; Gironas, J. A.; Vicuna, S.

    2015-12-01

    Given the critical role of the streamflow regime for ecosystem sustainability, modeling long term effects of climate change and land use change on streamflow is important to predict possible impacts in stream ecosystems. Because flow duration curves are largely used to characterize the streamflow regime and define indices of ecosystem health, they were used to represent and analyze in this study the stream regime in the Maipo River Basin in Central Chile. Water and Environmental Assessment and Planning (WEAP) model and the Plant Growth Model (PGM) were used to simulate water distribution, consumption in rural areas and stream flows on a weekly basis. Historical data (1990-2014), future land use scenarios (2030/2050) and climate change scenarios were included in the process. Historical data show a declining trend in flows mainly by unprecedented climatic conditions, increasing interest among users on future streamflow scenarios. In the future, under an expected decline in water availability coupled with changes in crop water demand, water users will be forced to adapt by changing water allocation rules. Such adaptation actions would in turns affect the streamflow regime. Future scenarios for streamflow regime show dramatic changes in water availability and temporal distribution. Annual weekly mean flows can reduce in 19% in the worst scenario and increase in 3.3% in the best of them, and variability in streamflow increases nearly 90% in all scenarios under evaluation. The occurrence of maximum and minimum monthly flows changes, as June instead of July becomes the driest month, and December instead of January becomes the month with maximum flows. Overall, results show that under future scenarios streamflow is affected and altered by water allocation rules to satisfy water demands, and thus decisions will need to consider the streamflow regime (and habitat) in order to be sustainable.

  2. Post-earthquake coastal evolution and recovery of an embayed beach in central-southern Chile

    NASA Astrophysics Data System (ADS)

    Martínez, Carolina; Rojas, Daniel; Quezada, Matías; Quezada, Jorge; Oliva, Ricardo

    2015-12-01

    Earthquakes and tsunamis are significant factors for change along active margin shores, and influence coastal evolution. The Chilean coast was affected in 2010 by a subduction earthquake with a magnitude of Mw 8.8 and also by a trans-Pacific tsunami, which generated violent geomorphologic changes and damaged homes. Following these events, the magnitude of the changes which affect Chile's central-southern coast (37°S) and the role of subduction earthquakes in coastal evolution on a historical scale were investigated. At Lebu bay (an embayed beach) data were generated for variations in time and space along the shoreline, topographical and bathymetric changes in the bay, and for morphodynamic littoral processes. Logarithmic and parabolic models were applied to the shoreline along with map overlays in order to determine changes. The shoreline processes were analyzed based on statistics for waves, tides and sediment transport for pre- and post-tsunami conditions. An average accretion rate of 2.80 m/year (1984-2010) was established for the shoreline, with a strong trend towards accretion in the last 30 years. A parabolic function best represented the general form of the shoreline, although the presence of a river in the concave zone affected the fit in this sector. Two factors controlled historical changes on the beach: one of anthropic origin in addition to the earthquake and tsunami on February 27th, 2010. The post-earthquake recovery was fast, and currently the beach is in a stable condition despite the inter-seismic subsidence process previous to the event. This coastal system showed a high resilience in the face of coastal geomorphological changes induced by high-impact natural disturbances. However, the opposite occurred in relation to changes induced by anthropogenic disturbances.

  3. Three-Dimensional Seismic Image of a Geothermal Prospect: Tinguiririca, Central Andes, Chile

    NASA Astrophysics Data System (ADS)

    Lira, E.; Comte, D.; Giavelli, A.; Clavero, J. E.; Pineda, G.

    2010-12-01

    Seismic monitoring has been widely used by the oil and gas industry, as a valuable input for the reservoir characterization. This tool has also been used in geothermal productive systems, particularly to understand permeability controls usually associated to shallow crustal fault systems that are seismically actives. Faults can be considered either “migration path” or “seals” in Petroleum Systems, depending on their activity story (they are carriers while actives and seals when the activity cease due to diagenetic processes in the fault plain). On the other hand, is well known that seismic velocities are strongly related to rock properties, in particular Vp/Vs and VpVs relationship has been successfully used to emphasize the variations in the physical rock properties due to fluid content and porosity. In geothermal systems, P and S-wave velocities are expected to be noticeably affected by massive hydrothermal alteration and/or to the presence of hot water in the fault related fractures of the rocks. In this job, the results of three months of seismic monitoring and a seismic velocity tomography are presented. Sixteen short period continuous recording, three components seismic stations were deployed in an area of approximately 20x10 Km2, and a large 8.8 magnitude earthquake took place during the recording period. The study area corresponds to the Tinguiririca volcanic complex (70°21''W, 35°48''S), in the high mountain of the Central Andes near the Chile-Argentina border. These preliminary results are complemented with some MT profiles, delineating potentially interesting geothermal features.

  4. Assessing the benefits and costs of dryland forest restoration in central Chile.

    PubMed

    Schiappacasse, Ignacio; Nahuelhual, Laura; Vásquez, Felipe; Echeverría, Cristian

    2012-04-30

    Investment in natural capital restoration is increasing as a response to the widespread ecological degradation of dryland forests. However, finding efficient mechanisms to promote restoration among private landowners is a significant challenge for policy makers with limited financial resources. Furthermore, few attempts have been made to evaluate the costs and benefits of restoration interventions even though this information is relevant to orient decision making. Hence, our goal was to estimate the benefits and costs of dryland forest restoration by means of reforestation with native trees in a study area in central Chile. To determine benefits we applied a Contingent Valuation questionnaire that allowed for the calculation of willingness to pay measures. Restoration costs were calculated based on market prices following existing technical recommendations developed for the study area. The results showed that the restoration project had a negative NPV irrespective of the discount rate applied in the analysis. Thus, the NPV varied between -US$71,000 and -US$258,000. The NPV attained positive results only for negative discount rates (US$15,039 for -2%) and only when the national subsidy available for forest restoration was taken into account. This shows that landowners in Colliguay do not have incentives for carrying out restoration interventions due to a classic market failure: that in which ecosystems are mismanaged because many of their benefits are externalities from the perspective of landowners. Overall, these results stress the need for developing new compensation mechanisms and enhancing those in existence, with the aim of making restoration competitive with other land uses.

  5. Interseismic strain accumulation in seismic gap of south central Chile from GPS measurements

    NASA Astrophysics Data System (ADS)

    Rudloff, A.; Vigny, C.; Ruegg, J. C.; Campos, J.

    2003-04-01

    Three campaigns of Global Positioning System (GPS) measurements were carried out in the Concepcion-Constitucion seismic gap in South Central Chile in 1996, 1999, and 2002. We observed a network of about 40 sites, made of 2 east-west transects roughly perpendicular to the trench ranging from the coastal area to the Argentina border and 1 north-south profile along the coast. Data sets were processed with MIT's GAMIT/GLOBK package. Horizontal velocities have formal uncertainties around 1 to 2 mm/yr in average. Vertical velocities are also determined and have uncertainties around 2 to 5 mm/yr. We find that the convergence between Nazca and South-America plates better matches the pole previously estimated by (Larson et al, 1997) than the Nuvel-1A estimate. Our estimate predicts a convergence of 72 mm/yr at N70 to be compared with Nuvel-1A 80 mm/yr at N79. With respect to stable South America, horizontal velocities decrease from 35 mm/yr on the coast to 14 mm/yr in the Cordillera. Vertical velocities help constraint lithospheric flecture. Partionning of the slightly oblique convergence will be investigated. The gradient of convergent parallel velocities reflects aseismic elastic loading on a zone of about 400 km width. Interestingly enough, this gradient exhibit a linear pattern, marginally compatible with the expected arctangent shape. 70 mm/yr of motion accumulated since the last big event in this area (1835 Earthquake described by Darwin) represent more than 10 m of displacement. Therefore, this area is probably mature for a next large earthquake, the magnitude of which could reach 8.5.

  6. Nematode community structure along a central Chile margin transect influenced by the oxygen minimum zone

    NASA Astrophysics Data System (ADS)

    Neira, Carlos; King, Ian; Mendoza, Guillermo; Sellanes, Javier; De Ley, Paul; Levin, Lisa A.

    2013-08-01

    Nematodes are among the metazoans most tolerant of low-oxygen conditions and play major roles in seafloor ecosystem processes. Nematode communities were studied in sediments off Concepción, Central Chile, spanning the outer shelf within the OMZ (122 m) to the mid-lower continental slope (972 m) beneath the OMZ. The total density and biomass of nematodes (core depth 0-10 cm) ranged from 677 to 2006 ind. 10 cm-2, and 168.4 to 506.5 μg DW 10 cm-2, respectively. Among metazoan meiofaunal taxa, nematodes predominated at all sites both in terms of relative abundance (83.7-99.4%) and biomass (53.8-88.1%), followed by copepods, nauplii and polychaetes. Nematodes were represented by 33 genera distributed among 17 families, with densities greatest at low oxygen sites (122-364 m; ~2000 ind. 10 cm-2). Nematode generic and trophic diversity, and individual biomass were lowest, and Rank 1 dominance was highest, at the most oxygen-depleted site (122 m), despite the fact that the organic carbon content of the sediment was maximal at this depth. At the most oxygenated slope sites (827 and 972 m), all of Wieser's nematode feeding groups were represented. In contrast, at the lowest-oxygen site, only selective deposit (bacterial) feeders (1A) were present, indicating a reduction in trophic complexity. A large percentage of nematodes inhabited subsurface sediment layers (>1 cm). At deeper, more oxygenated sites (827 and 972 m), nematode individual biomass increased downcore, while within the OMZ, nematode biomass was low and remained relatively uniform through the sediment column. The concentration of nematodes in deeper sediment layers, the vertical distribution of the feeding groups, as well as the high nutritional quality of the deeper layers, suggest a differential resource partitioning of the food available, which may reduce interspecific competition.

  7. Relationship between soil copper content and copper content of selected crop plants in central Chile.

    PubMed

    Badilla-Ohlbaum, R; Ginocchio, R; Rodríguez, P H; Céspedes, A; González, S; Allen, H E; Lagos, G E

    2001-12-01

    A survey of copper levels in agricultural soils of central Chile revealed two soil clusters-one with a mean copper level of 162 mg/kg and one with a mean copper level of 751 mg/kg of soil. Samples of soils from both soil clusters were characterized on the basis of physicochemical characteristics, and copper extractability was compared by saturation and CaCl2 extraction as well as an acid-leaching procedure (TCLP). We also measured the copper content of various tissues of tomato (Lycopersicon esculentum) and onion (Allium cepa) crops growing on these soils. Other than copper levels, soils from the two clusters were quite similar, with slightly greater levels of molybdenum and cadmium in the high-copper soils. Within each cluster, extracted copper levels and total soil copper levels were not correlated. However, the three extraction procedures solubilized significantly more copper from the high-Cu soils. Mineralogical characterization of the soil particles and depth profiles of soil metal levels in a subsample of sites suggested that highly insoluble copper ore and mining wastes might account for the high copper levels. Neither total nor extractable copper levels allowed statistical prediction of the levels of copper in plant tissue. The edible tissues of both crops had the same mean copper content, regardless of the copper soil level. However, copper contents of stems and leaves were significantly higher for plants growing on the high-Cu soils. These results show that in these soils, high copper levels are associated with very insoluble copper species and thus low bioavailability of copper to crop plants. PMID:11764158

  8. Geological Evidence of Predecessors to the 2010 Earthquake and Tsunami in South-Central Chile

    NASA Astrophysics Data System (ADS)

    Ely, L. L.; Cisternas, M.; Wesson, R. L.; Lagos, M.

    2010-12-01

    On February 27, 2010 a great M 8.8 earthquake and accompanying tsunami struck the region between Constitución and Concepción in south-central Chile. In the year immediately preceding this event, we described and surveyed deposits from previous tsunamis at several sites in the Concepción region (36.5°-38.5° S. Lat). This research positioned us to document the geomorphic and tectonic effects of the 2010 earthquake and tsunami. Following the 2010 earthquake we quantified the inundation, inland extent, erosion and deposition of the 2010 tsunami at our study sites and compared with those of previous tsunamis. The 2010 tsunami deposits were also utilized to guide the search for repositories where stratigraphic records of multiple paleotsunami deposits are likely to be preserved. The characteristic of the 2010 tsunami were similar to those reported after the penultimate earthquake in the Concepción region, which occurred in 1835. A sand sheet from the 2010 tsunami blanketed sites at Tirua (38.5° S. Lat) and the Andalien River, (36.7° S. Lat), where we had identified preexisting anomalous, laterally-continuous sand sheets that thin landward and are interbedded with coastal marsh deposits. The great similarity between these and the 2010 tsunami sands substantiated our interpretation that they were also left by previous tsunamis. At the Tirua River estuary, the 2010 tsunami sand sheet is underlain by at least three earlier tsunami deposits. This site lies at the boundary between the northern end of the rupture zone from the M 9.5 earthquake in 1960 and the southernmost reports of the 1835 and 2010 tsunamis. Prominent, laterally-continuous bands of these tsunami sands are interbedded with silty peats along the bank of the Tirua River, 0.8 to 1.8 km inland from the coast. Based on buried historic artifacts and testimonies of local survivors, the youngest pre-2010 sand sheet was deposited by the 1960 tsunami. Preliminary radiocarbon and OSL ages on the lower two sand

  9. Tsunami Rapid Assessment Using High Resolution Images and Field Surveys: the 2010 , Central Chile, and the 2011, Tohoku Tsunamis

    NASA Astrophysics Data System (ADS)

    Ramirez-Herrera, M.; Navarrete-Pacheco, J.; Lagos, M.; Arcas, D.

    2013-12-01

    Recent extreme tsunamis have shown their major socioeconomic impact and imprint in the coastal landscape. Extensive destruction, erosion, sediment transport and deposition resculpted coastal landscape within few minutes along hundreds of kilometers of the Central Chile, in 2010, and the Northeast coast of Japan, in 2011. In the central coast of Chile, we performed a post-tsunami survey a week after the tsunami due to access restrictions. Our observations focus on the inundation and geomorphic effects of the 2010 tsunami and included an air reconnaissance flight, analysis of pre- and post-event low fly air-photographs and Google Earth satellite images, together with ground reconnaissance and mapping in the field, including topographic transects, during a period of 13 days. Eyewitness accounts enabled us to confirm our observations on effects produced by the tsunami along ~ 500km along the coastline landscape in central Chile For the Tohoku case study, we assessed in a day tsunami inundation distances and runup heights using satellite data (very high resolution satellite images from the GeoEye1 satellite and from the DigitalGlobe worldview through the Google crisis response project, SRTM and ASTER GDEM) of the Tohoku region, Northeast Japan. Field survey data by Japanese, other international scientists and us validated our results. The rapid assessment of damage using high-resolution images has proven to be an excellent tool neccessary for effcient postsunami surveys as well as for rapid assessment of areas with access restrictions. All countries, in particular those with less access to technology and infrastructure, can benefit from the use of freely available satellite imagery and DEMs for an initial, pre-field survey, rapid estimate of inundated areas, distances and runup, tsunami effects in the coastal geomorphology and for assisting in hazard management and mitigation after a natural disaster. These data provide unprecedented opportunities for rapid assessment

  10. Latitudinal Discontinuity in Thermal Conditions along the Nearshore of Central-Northern Chile

    PubMed Central

    Tapia, Fabian J.; Largier, John L.; Castillo, Manuel; Wieters, Evie A.; Navarrete, Sergio A.

    2014-01-01

    Over the past decade, evidence of abrupt latitudinal changes in the dynamics, structure and genetic variability of intertidal and subtidal benthic communities along central-northern Chile has been found consistently at 30–32°S. Changes in the advective and thermal environment in nearshore waters have been inferred from ecological patterns, since analyses of in situ physical data have thus far been missing. Here we analyze a unique set of shoreline temperature data, gathered over 4–10 years at 15 sites between 28–35°S, and combine it with satellite-derived winds and sea surface temperatures to investigate the latitudinal transition in nearshore oceanographic conditions suggested by recent ecological studies. Our results show a marked transition in thermal conditions at 30–31°S, superimposed on a broad latitudinal trend, and small-scale structures associated with cape-and-bay topography. The seasonal cycle dominated temperature variability throughout the region, but its relative importance decreased abruptly south of 30–31°S, as variability at synoptic and intra-seasonal scales became more important. The response of shoreline temperatures to meridional wind stress also changed abruptly at the transition, leading to a sharp drop in the occurrence of low-temperature waters at northern sites, and a concurrent decrease in corticated algal biomass. Together, these results suggest a limitation of nitrate availability in nearshore waters north of the transition. The localized alongshore change results from the interaction of latitudinal trends (e.g., wind stress, surface warming, inertial period) with a major headland-bay system (Punta Lengua de Vaca at 30.25°S), which juxtaposes a southern stretch of coast characterized by upwelling with a northern stretch of coast characterized by warm surface waters and stratification. This transition likely generates a number of latitude-dependent controls on ecological processes in the nearshore that can explain species

  11. Low temperature responses of Nothofagus dombeyi and Nothofagus nitida, two evergreen species from south central Chile.

    PubMed

    Reyes-Díaz, M; Alberdi, M; Piper, F; Bravo, L A; Corcuera, L J

    2005-11-01

    Nothofagus dombeyi (Mirb.) Blume and Nothofagus nitida (Phil.) Krasser are closely related evergreen trees native to south central Chile. Nothofagus dombeyi is a pioneer in habitats subject to high daytime irradiances and nighttime freezing temperatures and has a wider altitudinal and latitudinal distribution than N. nitida, which is restricted to more oceanic climates. We postulated that N. dombeyi has a greater cold-acclimation capacity, expressed as a greater capacity to maintain a functional photosynthetic apparatus at low temperatures, than N. nitida. Because cold-acclimation may be related to the accumulation of cryoprotective substances, we investigated relationships between ice nucleation temperature (IN), freezing temperature (FT), and the temperature causing injury to 50% of the leaf tissues (LT(50)) on the one hand, and concentrations of total soluble carbohydrates (TSC), starch and proline on the other hand. Observations were made throughout a seasonal cycle in adults and seedlings in the field and in seedlings in the laboratory under cold-acclimation inductive and non-inductive conditions. In adults, LT(50) values were lower in N. dombeyi than in N. nitida, suggesting that N. dombeyi is the more frost tolerant species. Adults of both species tolerated freezing in autumn and winter but not in spring and summer. In the fall and winter, seedlings of N. dombeyi had a much lower LT(50) than those of N. nitida. Nothofagus nitida seedlings, in autumn and winter, exhibited freezing avoidance mechanisms. Although elevated TSC and proline concentrations may contribute to freezing tolerance in adults of both species, an increase in proline concentration is unlikely to be the dominant frost tolerance response in adults because proline concentrations were higher in N. nitida than in N. dombeyi. In seedlings, however, there were large differences in proline accumulation between species that may account for the difference between them in freezing tolerance. Starch

  12. Modelling distributed ablation on Juncal Norte Glacier, dry Andes of central Chile

    NASA Astrophysics Data System (ADS)

    Carenzo, Marco; Pellicciotti, Francesca; Helbing, Jakob; Dadic, Ruzica; Burlando, Paolo

    2010-05-01

    In the Aconcagua River Basin, in the dry Andes of central Chile, water resources in summer originate mostly from snow and ice glacier melt. Summer seasons are dry and stable, with precipitation close to zero, low relative humidity and very intense solar radiation. The region's economic activities are dependent on these water resources, but their assessment is still incomplete and an effort is needed to evaluate present and future changes in water from glacier and seasonal snow covers in this area. The main aim of this paper is to simulate glacier melt and runoff from Juncal Norte Glacier, in the upper Aconcagua Basin, using models of various complexity and data requirement. We simulate distributed glacier ablation for two seasons using an energy-balance model (EB) and an enhanced temperature-index model (ETI). Meteorological variables measured at Automatic Weather Stations (AWSs) located on and off-glacier are extrapolated from point observations to the glacier-wide scale. Shortwave radiation is modelled with a parametric model taking into account shading, reflection from slopes and atmospheric transmittance. In the energy-balance model, the longwave radiation flux is computed from Stefan-Boltzmann relationships and turbulent fluxes are calculated using the bulk aerodynamic method. The EB model includes subsurface heat conduction and gravitational redistribution of snow. Glacier runoff is modelled using a linear reservoir approach accounting for the temporal evolution of the system. Hourly simulations of glacier melt are validated against ablation observations (ultrasonic depth gauge and ablation stakes) and runoff measured at the glacier snout is compared to a runoff record obtained from a combination of radar water level measurements and tracer experiments. Results show that extrapolation of meteorological input data, and of temperature in particular, is the largest source of model uncertainty, together with snow water equivalent initial conditions. We explore

  13. Primary production and phytoplanktonic biomass in shallow marine environments of central Chile: Effect of coastal geomorphology

    NASA Astrophysics Data System (ADS)

    Henríquez, Luis A.; Daneri, Giovanni; Muñoz, Carlos A.; Montero, Paulina; Veas, Rodrigo; Palma, Alvaro T.

    2007-06-01

    Fluctuations were identified and quantified, on a local spatial scale, in net primary production (NPP), phytoplanktonic biomass (Chl a), and photosynthetic parameters ( PmaxB and αB) of natural phytoplankton assemblages in coastal environments of central Chile. The measurements, besides those of a series of environmental parameters, were carried out at two locations: once a month from August 2003 to February 2004 at a location on the Hualpén Peninsula (HP) (36°44') and five times during February 2005 at a location on the Quintay Peninsula (QP) (33°11'). The measurements at both the locations were carried out simultaneously, at exposed and protected sites at similar distances from the coast and the tip of each peninsula, to ascertain whether any physical characteristics of the protected environments favor the retention of phytoplankton, which, in turn, translates into greater NPP and higher values of PmaxB and αB. Photosynthetic parameters were estimated through the analysis of P vs. I curves drawn from incubation in closed systems in the laboratory with light intensity (μE m -2 s -1) as the independent variable and maximum gross primary production ( PmaxB expressed as μg C μg Chl a-1 h -1) and the initial slope of the curve ( αB expressed as (μg C μg Chl a-1 h -1)/(μE m -2 s -1)) as the dependent variables. The results were as follows: (1) in most cases, PmaxB, αB, and NPP were greater at the protected site on HP; (2) PmaxB was greater only in two instances at the protected site on QP whereas αB did not differ between the two sites; (3) the concentration of subsurface Chl a at QP was always higher at the protected sites on both the peninsulas while surface Chl a did not exhibit a clear pattern at either peninsula; (4) the Secchi depth was greater at the exposed sites on both peninsulas, and (5) the average thermal stratification of a water column was greater at the protected sites. We propose that coastal geomorphology, through contrasting circulation

  14. Magnetotelluric Studies of the Laguna del Maule Volcanic Field, Central Chile

    NASA Astrophysics Data System (ADS)

    Cordell, D. R.; Unsworth, M. J.; Diaz, D.; Pavez, M.; Blanco, B.

    2015-12-01

    Geodetic data has shown that the surface of the Laguna del Maule (LdM) volcanic field in central Chile has been moving upwards at rates >20 cm/yr since 2007 over a 200 km2 area. It has been hypothesized that this ground deformation is due to the inflation of a magma body at ~5 km depth beneath the lake (2.8 km b.s.l.). This magma body is a likely source for the large number of rhyolitic eruptions at this location over the last 25 ka. A dense broadband magnetotelluric (MT) array was collected from 2009 to 2015 and included data from a geothermal exploration project. MT phase tensor analysis indicates that the resistivity structure of the region is largely three-dimensional for signals with periods longer than 1 s, which corresponds to depths >5 km. The MT data were inverted using the ModEM inversion algorithm to produce a three-dimensional electrical resistivity model which included topography. Four primary features were identified in the model: 1) A north-south striking, 10 km by 5 km, low-resistivity zone (<5 Ωm) northwest of the inflation centre at a depth of ~5 km (2.8 km b.s.l.) is interpreted as a zone of partial melt which may be supplying material via conduits to account for the observed ground deformation; 2) A shallow low-resistivity feature ~400 m beneath the lake surface (1.8 km a.s.l.) and spatially coincident with the inflation centre is interpreted to be a zone of hydrothermal alteration; 3) A thin, low-resistivity feature to the west of LdM at a depth of ~250 m (2.2 km a.s.l.) is interpreted to be the clay cap of a potential geothermal prospect; 4) A large, low-resistivity zone beneath the San Pedro-Tatara Volcanic Complex to the west of LdM at a depth of ~10 km (8 km b.s.l.) is interpreted to be a zone of partial melt. Further MT data collection is planned for 2016 which will expand the current grid of MT stations to better constrain the lateral extent of the observed features and give greater insight into the dynamics of this restless magma system.

  15. Geology, K-Ar geochronology and paleomagnetism of parts of the coastal cordillera of central Chile, South America

    SciTech Connect

    Irwin, J.J.

    1986-01-01

    A complex composed of ultrabasic and basaltic lavas, chert-argillite, arkose and conglomerate was assembled in the coast of north central Chile prior to 220 Ma ago. Three major episodes of deformation and metamorphism have been observed in this area. The first episode of deformation and metamorphism (F/sub 1/) produced a compositional layering (S/sub 1/) and amphibolite facies metamorphism within the formations listed above. This episode of deformation and metamorphism occurred coevally with intrusion of a regionally extensive 220-200 Ma fine grained gabbro and granitic complex. The second episode of deformation and metamorphism locally formed tight, recumbent folds in S/sub 1/ and at least one low angle reverse fault. K-Ar and Rb-Sr ages on units in which F/sub 2/ folds are well developed range between 163 and 140 Ma. A third episode of deformation and low grade metamorphism (F/sub 3/) locally formed upright, open to tight folds with sharp hinges and axial planes that strike north and dip steeply east. Igneous intrusions that were affected by F/sub 3/ yield K-Ar ages between 140 Ma and 126 Ma. Undeformed cross cutting mafic dykes have been dated by K-Ar at 121 Ma. Paleomagnetic samples collected from 19 sites in radioisotopically dated (using the K-Ar and /sup 40/Ar-/sup 39/Ar techniques) Jurassic mafic dykes and plutons in the coastal cordillera of Chile yield mean paleomagnetic poles that are consistent with the average pole from coeval sequences within the South American craton. The paleomagnetic directions are consistent over the latitudinal range and variety of lithologies encompassed by this study. Paleomagnetic results presented here indicate that no major rotation or translation of crustal blocks has been taken place in this part of central Chile since middle Jurassic time.

  16. Variable coupling controls the seismic segmentation and transient creep on the central Chile subduction

    NASA Astrophysics Data System (ADS)

    Metois, M.; Socquet, A.; Vigny, C.

    2010-12-01

    Part of the Nazca-South America convergence rate (68 mm/yr) is taken up by permanent strain contributing to the building of the Andes, but most of it generates elastic deformation recovered during the seismic cycle with an average of one M˜ 8 event every ten years and at least one M> 8.7 per century along the Chilean subduction zone. Surface deformation is representative of these processes and GPS measurements made in the area aim at quantifying the different contributions, defining the style of deformation and discriminating between the different models proposed. We combined all interseismic GPS measurements available in Chile and recent measurements we carried out on small scale, dense networks in a common reference frame. We inverted those data to assess the amount of coupling along depth and latitude on the subduction plane between 24°S and 40°S using Okada's elastic equations and backslip assumption developped by Savage. We demonstrate that modelling this deformation with a full coupling on the trench is not possible everywhere, and we conclude that coupling must be varying on the subduction interface both with depth and along strike. Coupling can reach value as low as 40% at regional scale and even less locally. We find that very low coupling small-scale areas correlate well with historical earthquake segmentation, coastal anomalies and subduction of bathymetric features of the Nazca plate. In particular, the La Serena Bay (30°S-28°S) where the locked zone vanishes seems to be a stable boundary for historical events. We show that the Maule region (from 38°S to 34°S) that the feb. 27th of 2010 (Mw 8.8) event ruptured with two main patches of slip, was characterized by a well developped fully locked zone that extents far indepth (10 to 60km) and narrows where the earthquake stopped propagating (San Antonio at 34°S and south of Arauco peninsula at 38°S). Deep postseismic slip assessed from GPS data correlates with the downdip transition zone

  17. Connecting the dots: Water as a key variable of climate change vulnerability in Mediterranean locations of Central Chile.

    NASA Astrophysics Data System (ADS)

    Meza, F. J.; Bambach, N.; Puertas, O.; Poblete, D.; Bonelli, S.; Gironas, J. A.; Vicuna, S.; Bustos, E.

    2011-12-01

    Chile's central territory is characterized by the presence of a typical Mediterranean with strong seasonality in its precipitation regime. Spanned over almost 1200 km., this region holds several important economic sectors and large cities that strongly depend on winter precipitation and spring summer snow melt discharge for the satisfaction of their water demands. Current climate change projections developed for this region, show an increase in temperature and decrease in precipitation that may well affect water resources both from a demand and supply sides. To the extent that the climate becomes drier and warmer, river discharge will be affected both in magnitude and seasonality, and the rate of evaporation will increase. As a consequence, we believe that several important activities, such as the provision of potable water, generation of electricity and the ability to maintain economically viable yields in irrigated agriculture, will be put at risk especially if other global change drivers start to materialize. We also argue that a basic sectorial impact assessment show important limitations, and that it is necessary to expand the framework of current analysis and capture interactions between water competing sectors including also ecologically driven water demands. The aim of this work is to revise existing evidence of the impacts of climate change on water resources in Mediterranean central Chile and discuss the implications that these impacts will change for different sectors in a more integrated manner. We also present some new avenues for research and intervention that have to be explored in order to refine assessments and facilitate the adaptation process.

  18. Alteration patterns of chromian spinels from La Cabaña peridotite, south-central Chile

    NASA Astrophysics Data System (ADS)

    Barra, Fernando; Gervilla, Fernando; Hernández, Elkin; Reich, Martin; Padrón-Navarta, José Alberto; González-Jiménez, José Maria

    2014-12-01

    La Cabaña peridotite is part of a dismembered ophiolite complex located within the metamorphic basement of the Coastal Cordillera of south-central Chile, and is the only location in Chile were Cr-spinels have been described so far. The La Cabaña peridotite is part of the Western Series unit, which comprises meta-sedimentary rocks, metabasites, and serpentinized ultramafic rocks. This unit has been affected by greenschist-facies metamorphism with reported peak PT conditions of 7.0-9.3 kbar and 380°-420 °C. Within La Cabaña peridotite Cr-spinels are present in two localities: Lavanderos and Centinela Bajo. In Lavanderos, Cr-spinel occurs in small chromitite pods and as accessory/disseminated grains with a porous or spongy texture in serpentinite, whereas in Centinela Bajo Cr-spinel is present as accessory zoned grains in partly serpentinized dunites, and in chromitite blocks. All Cr-spinels display variable degrees of alteration to Fe2+-rich chromite with a variation trend of major elements from chromite to Fe2+-rich chromite similar to those observed in other locations, i.e., an increase in Fe2O3 and FeO, a decrease in Al2O3 and MgO. Cr2O3 content increases from chromite to Fe2+-rich chromite in chromitite pods from Lavanderos and chromitite blocks from Centinela Bajo, but decreases in ferrian chromite zones in accessory grains from Centinela Bajo. The minor element (Ti, V, Zn, Ni) content is mostly low and does not exceed 0.4 wt.%, with the exception of MnO (<0.9 wt.%), which shows a correspondence with increasing degree of alteration. Cr# (Cr/Cr + Al) versus Mg# (Mg/Mg + Fe2+) and Fe3+/Fe3++Fe2+ versus Mg# plots are used to illustrate the Cr-spinel alteration process. Overall, the Cr-spinels from Lavanderos (chromitite pods and disseminated grains) exhibit Cr# values ranging from 0.6 to 1.0, Mg# (Mg/Mg + Fe2+) below 0.5, and (Fe3+/Fe3++Fe2+) <0.4. Cr-spinels from chromitites in Centinela Bajo have Cr# and Mg# values that range from 0.65 to 1.0, and 0

  19. Interseismic strain accumulation in south central Chile from GPS measurements, 1996-1999

    NASA Astrophysics Data System (ADS)

    Ruegg, J. C.; Campos, J.; Madariaga, R.; Kausel, E.; de Chabalier, J. B.; Armijo, R.; Dimitrov, D.; Georgiev, I.; Barrientos, S.

    2002-06-01

    Two campaigns of Global Positioning System (GPS) measurements were carried out in the Concepción-Constitución area of Chile in 1996 and 1999. It is very likely that this area is a mature seismic gap, since no subduction earthquake has occurred there since 1835. In 1996, 32 sites were occupied in the range 35°S-37°S, between the Pacific coast of Chile and the Andes near the Chile-Argentina border. In 1999, the network was extended by the installation of 9 new points in the Arauco region whereas 13 points among the 1996 stations were reoccupied. The analysis of this campaign data set, together with the data recorded at eight continuous GPS sites (mostly IGS stations) in South America and surrounding regions, indicates a velocity of about 40 +/- 10 mm/yr in the direction N80-90°S for the coastal sites with respect to stable cratonic South America. This velocity decreases to about 20-25 mm/yr towards the Andes. We interpret this result as reflecting interseismic strain accumulation above the Nazca-South America subduction zone, due to a locked thrust zone extending down to about 60 km depth.

  20. Paleomagnetism in the Precordillera of northern Chile (22°30'S): implications for the history of tectonic rotations in the Central Andes

    NASA Astrophysics Data System (ADS)

    Somoza, Rubén; Tomlinson, Andrew

    2002-01-01

    Widespread clockwise rotations in Mesozoic and Lower Tertiary rocks of northern Chile have been interpreted as the sum of two rotational events separated in time: an early rotation related to local deformation plus a late rotation related to wholesale rotation of northern Chile linked to Late Cenozoic oroclinal bending in the Central Andes. In this paper we report new paleomagnetic data from Cretaceous, upper Oligocene and Miocene sedimentary rocks in the Precordillera of northern Chile. The results suggest that all these rocks acquired their remanence at or close to the time of deposition. The lack of rotation in undeformed lower Miocene strata clearly indicates that clockwise rotations found in underlying, faulted and folded Cretaceous rocks were completed before the Late Cenozoic. Results from nearby localities in deformed upper Oligocene strata would argue for little (˜5°) rotation since the late Oligocene. Data from widely separated Miocene localities covering an area of about 5000 km 2 in the Calama basin strongly suggest that northern Chile did not undergo significant wholesale rotation during the Late Cenozoic. This, together with previous paleomagnetic evidence against Neogene rigid-body-like rotation of the southern Peruvian forearc, suggests that the curved shape of the Central Andean forearc was not significantly enhanced during the Late Cenozoic. By inference, all of the rotation in most Mesozoic and Lower Tertiary rocks of northern Chile was accomplished in the Cretaceous and/or Early Cenozoic, when the locus of deformation in the Central Andes was localized in the present forearc region.

  1. Locomotor activity and zonation of upper shore arthropods in a sandy beach of north central Chile

    NASA Astrophysics Data System (ADS)

    Jaramillo, E.; Contreras, H.; Duarte, C.; Avellanal, M. H.

    2003-10-01

    The tenebrionid beetle Phalerisida maculata Kulzer, the talitrid amphipod Orchestoidea tuberculata Nicolet and the oniscid isopod Tylos spinulosus Dana are semi-terrestrial burrowing species, which coexist on sandy beaches of north central Chile (28-30°S). During the night, these scavengers emerge to make downshore migrations. Given the similarity in niches of these three species (all are known to include macroalgal detritus in their diet) and their relatively high abundance on that beaches, there is the potential for some degree of interaction, both inter- and intraspecific. Field studies were carried out to examine zonation of these burrowing organisms and eventual time and/or space partitioning of locomotor activity during night hours. Locomotor activity on the beach surface was analyzed over 12 h periods during spring and neap tides of September and December 2000, and March 2001. Scavengers moving over the beach surface were captured using pitfall traps buried with their rims flush with the beach surface along a transect extended from the foot of the dunes to the highest levels reached by the swashes. Every 1 h the captured animals in the traps were collected. Locomotor activity was also studied in the laboratory with chambers equipped with infrared recording systems (actographs). Data downloaded from the actographs were graphed to obtain a display of locomotor activity per 15 min interval during the course of the 7 day experiments. Results show space partitioning of burrowed organisms and time partitioning in the locomotor activity of O. tuberculata, T. spinulosus and P. maculata over the beach surface. Circular statistics showed that usually the activity peaks of O. tuberculata were more different from those of P. maculata and T. spinulosus than those of the last two species when compared with each other. Intraspecific differences were also found in the surface locomotor activity, primarily between juveniles and adults of O. tuberculata. Interseasonal

  2. Do heat and smoke increase emergence of exotic and native plants in the matorral of central Chile?

    NASA Astrophysics Data System (ADS)

    Figueroa, Javier A.; Cavieres, Lohengrin A.; Gómez-González, Susana; Montenegro, Marco Molina; Jaksic, Fabian M.

    2009-03-01

    We studied the effect of heat shock and wood-fueled smoke on the emergence of native and exotic plant species in soil samples obtained in an evergreen shrubland of central Chile, located on the eastern foothills of the Coastal Range of Lampa. Immediately after collection samples were dried and stored under laboratory condition. For each two transect, 10 samples were randomly chosen, and one of the following treatments was applied: 1) Heat-shock treatment. 2) Plant-produced smoke treatment. 3) Combined heat-and-smoke treatment. 4) Control, corresponding to samples not subjected to treatment. Twenty-three species, representing 12 families, emerged from the soil samples. The best-represented families were Poaceae and Asteraceae. All of the emerged species were herbs, 21 were annuals, and 14 were exotic to Chile. Fire-related triggers used in this study did not increase the emergence and/or abundance of exotic species with respect to natives in soil samples. Interestingly, this study provides evidence that heat-shock can increase the emergence of native herbs.

  3. Remotely triggered microearthquakes and tremor in central California following the 2010 Mw 8.8 Chile earthquake

    USGS Publications Warehouse

    Peng, Zhigang; Hill, David P.; Shelly, David R.; Aiken, Chastity

    2010-01-01

    We examine remotely triggered microearthquakes and tectonic tremor in central California following the 2010 Mw 8.8 Chile earthquake. Several microearthquakes near the Coso Geothermal Field were apparently triggered, with the largest earthquake (Ml 3.5) occurring during the large-amplitude Love surface waves. The Chile mainshock also triggered numerous tremor bursts near the Parkfield-Cholame section of the San Andreas Fault (SAF). The locally triggered tremor bursts are partially masked at lower frequencies by the regionally triggered earthquake signals from Coso, but can be identified by applying high-pass or matched filters. Both triggered tremor along the SAF and the Ml 3.5 earthquake in Coso are consistent with frictional failure at different depths on critically-stressed faults under the Coulomb failure criteria. The triggered tremor, however, appears to be more phase-correlated with the surface waves than the triggered earthquakes, likely reflecting differences in constitutive properties between the brittle, seismogenic crust and the underlying lower crust.

  4. The Triassic Santa Juana Formation at the lower Biobío River, south central Chile

    NASA Astrophysics Data System (ADS)

    Nielsen, Sven N.

    2005-09-01

    A sequence of Triassic rocks is exposed near the town of Concepción, Chile. These clastic strata are interpreted as the deposits of rivers, lakes, playas, and alluvial fans. The deposits comprise conglomerates, arkosic sandstones, and sand-, silt- and mudstones. Four facies associations comprising eight sedimentary facies can be distinguished. Plant fossils from the sedimentary sequence of the Santa Juana Formation indicate a Carnian age. The flora includes ferns ( Gleichenites, Cladophlebis, Dictyophyllum, Thaumatopteris, Asterotheca, Saportaea) and seed ferns ( Kurtziana, Antevsia, Dicroidium), ginkgophytes ( Sphenobaiera), cycads ( Pseudoctenis), conifers ( Heidiphyllum, Telemachus, Rissikia), and gymnosperms of uncertain affinities ( Linguifolium, Gontriglossa). Two new species are presented: Pseudoctenis santajuanensis and Gontriglossa reinerae.

  5. Landscape Analysis of Adult Codling Moth (Lepidoptera: Tortricidae) Distribution and Dispersal within Typical Agroecosystems Dominated by Apple Production in Central Chile

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We analyzed the spatial distribution and dispersal of codling moth, Cydia pomonella (L.), adults within two heterogeneous agro-ecosystems typical of central Chile; commercial apple, Malus domestica Borkhausen, orchards surrounded by various unmanaged host plants. Both a geostatistical analysis of ca...

  6. Osseous skeletal material and fish scales in marine sediments under the oxygen minimum zone off northern and central Chile

    NASA Astrophysics Data System (ADS)

    Milessi, Andrés C.; Sellanes, Javier; Gallardo, Víctor A.; Lange, Carina B.

    2005-08-01

    The significance of whale falls for the study of the biogeography, evolution and biodiversity of deep-sea biota has been recently recognized by international programs since large carcasses are known to give rise to biogenic chemosynthetic ecosystems. However, the plain accumulation of smaller bone material in the shallower settings of the continental shelf and upper slope under the hypoxic conditions of the Oxygen Minimum Zone (OMZ), has received much less attention. Here we describe new findings of skeletal material and fish scales in marine sediments under the OMZ off northern and central Chile which, combined with previous reports for the study area, lead us to suggest the existence of a band in the benthos of accumulation of bones and scales extending at least twenty degrees in latitude (18-38° S). Future studies should focus on the characterization of biotic communities living upon these resources in order to elucidate their peculiarities and importance in the Eastern South Pacific.

  7. Use of high-resolution satellite images for detection of geological structures related to Central Andes geothermal field, Chile.

    NASA Astrophysics Data System (ADS)

    Benavides-Rivas, C. L.; Soto-Pinto, C. A.; Arellano-Baeza, A. A.

    2014-12-01

    Central valley and the border with Argentina in the center, and in the fault system Liquiñe-Ofqui in the South of the country. High resolution images from the LANDSAT 8 satellite have been used to delineate the geological structures related to the potential geothermal reservoirs located at the northern end of the Southern Volcanic Zone of Chile. It was done by applying the lineament extraction technique, using the ADALGEO software, developed by [Soto et al., 2013]. These structures have been compared with the distribution of main geological structures obtained in the field. It was found that the lineament density increases in the areas of the major heat flux indicating that the lineament analysis could be a power tool for the detection of faults and joint zones associated to the geothermal fields. A lineament is generally defined as a straight or slightly curved feature in the landscape visible satellite image as an aligned sequence of pixel intensity contrast compared to the background. The system features extracted from satellite images is not identical to the geological lineaments that are generally determined by ground surveys, however, generally reflects the structure of faults and fractures in the crust. A temporal sequence of eight Landsat multispectral images of Central Andes geothermal field, located in VI region de Chile, was used to study changes in the configuration of the lineaments during 2011. The presence of minerals with silicification, epidotization, and albitization, which are typical for geothrmal reservoirs, was also identified, using their spectral characteristics, and subsequently corroborated in the field. Both lineament analysis and spectral analysis gave similar location of the reservoir, which increases reliability of the results.

  8. Applying an ecosystem service approach to unravel links between ecosystems and society in the coast of central Chile.

    PubMed

    de Juan, Silvia; Gelcich, Stefan; Ospina-Alvarez, Andres; Perez-Matus, Alejandro; Fernandez, Miriam

    2015-11-15

    Ecosystem-based management implies understanding feedbacks between ecosystems and society. Such understanding can be approached with the Drivers-Pressures-State change-Impacts-Response framework (DPSIR), incorporating stakeholders' preferences for ecosystem services to assess impacts on society. This framework was adapted to six locations in the central coast of Chile, where artisanal fisheries coexist with an increasing influx of tourists, and a set of fisheries management areas alternate with open access areas and a no-take Marine Protected Area (MPA). The ecosystem services in the study area were quantified using biomass and species richness in intertidal and subtidal areas as biological indicators. The demand for ecosystem services was elicited by interviews to the principal groups of users. Our results evidenced decreasing landings and a negative perception of fishermen on temporal trends of catches. The occurrence of recreational fishing was negligible, although the consumption of seafood by tourists was relatively high. Nevertheless, the consumption of organisms associated to the study system was low, which could be linked, amongst other factors, to decreasing catches. The comparison of biological indicators between management regimens provided variable results, but a positive effect of management areas and the MPA on some of the metrics was observed. The prioritising of ecosystem attributes by tourists was highly homogenous across the six locations, with "scenic beauty" consistently selected as the preferred attribute, followed by "diversity". The DPSIR framework illustrated the complex interactions existing in these locations, with weak linkages between society's priorities, existing management objectives and the state of biological communities. Overall, this work improved our knowledge on relations between components of coastal areas in central Chile, of paramount importance to advance towards an ecosystem-based management in the area.

  9. Multiproxy approach revealing climate and cultural changes during the last 26kyrs in south-central Chile

    NASA Astrophysics Data System (ADS)

    Abarzua, Ana M.; Jarpa, Leonora; Martel, Alejandra; Vega, Rodrigo; Pino, Mario

    2010-05-01

    Multiproxy approach from Purén Lumaco Valley (38°S) describes the paleonvironmental history during the Last Maximum Glacial (LGM) in south-central Chile. Three sediment cores and severals AMS 14C dates were used to perform a complete pollen, diatoms, chironomids, and sedimentological records demonstrating the existence of a large and non profundal paleolake, between 25 and 20kyr BP. Some of these evidence are laminated silty-clay sediments (lacustrine rhythmites), associated with the presence of siderite mineral (FeCO3), besides biological proxies like Fragilaria construens and Stauroforma inermes (planctonic diatoms), and Dicrotendipes sp. and Tanytarsini tribe (littoral chironomids). The pollen ensemble reveals the first glacial refuge of Araucaria araucana forests in the low lands during the LGM. The lake was drained abruptly into a swamp/bog at 12kyr BP and colonized by Myrtaceae wet forest. This evidence suggest the dry/warm climate period of early Holocene in south-central Chile. Later, the sediments indicate variable lacustrine levels, and increase of charcoal particles, associated to current climatic conditions. The pollen spectrum dominated by Myrtaceae and Nothofagus contrasts with a strongly disturb current landscape. Actually, Purén-Lumaco valley constitutes a complex peat-bog system dominated by exotic grasses and forest species (Tritricum aestivum, Pinus radiata and Eucalyptus spp.). Some archaeological antecedents in the area document the human development at ca. 7yrs BP. The greatest archaeological characteristic present in the valley is the kuel, a Mapuche earth accumulation. The presence and extension of almost 300 kuel in the valley reflect the social/economic development, and partly explains why the region was the major resistance area for Spanish colonizer during XVI-XVII centuries. Also the archaeological findings reveal the presence of maize pollen (Zea mays) within their food consumption. The influence of climate and human impact in

  10. Using glacial morphology to constrain the impact of the Chile active spreading ridge subduction in Central Patagonia

    NASA Astrophysics Data System (ADS)

    Scalabrino, B.; Ritz, J. F.; Lagabrielle, Y.

    2009-04-01

    The Central Patagonian Cordillera is a unique laboratory to study interaction between oceanic and continental lithospheres during the subduction of an active spreading ridge beneath a continent. The subduction of the South Chile spreading Ridge, which separates the Nazca plate from the Antarctic plate, started ca. 15-14 Ma at the southern tip of Patagonia (55°S latitude). The northwards migration of the Chile Triple Junction induces the subduction of several segments especially around 46°S latitude. There, three segments subducted at ca. 6, 3 and 0.3 Ma, leading to the formation of a large asthenospheric slab-window beneath Central Patagonia. Contemporaneously, the Central Patagonia reliefs are undergoing major glacial events since at least 7 Ma. These events are evidenced to the east of the Central Patagonian morphotectonic front within perched relict surfaces. Inset in these perched glacial surfaces are found mid-Pleistocene glacial valleys, as the Lake General Carrera-Buenos Aires amphitheatre (LGCBA), which formed between 1.1 Ma and 16 ka. We used the relationships between the glacial valleys and the volcanism associated with the asthenospheric slab-window to better constraints the structural evolution of the Patagonian Cordillera related to the subduction of the Chili active spreading Ridge. The present work focused within two well-preserved perched flat surfaces named Meseta del Lago Buenos Aires and Meseta del Cerro Galera: (i) The meseta del Lago Buenos Aires defines a plateau made of interbedded units of tills and lavas dated between 12 Ma and 3 Ma. The top surface of the meseta, ˜2000 meters high is dated at 3 Ma, and is shaped by four NE-SW trending glacial lobes characterized with kettles, lineations and moraines. The glacial valleys are beheaded westwards and define perched valleys 200 to 400 meters higher than the western Cordillera. This suggests recent vertical movement along N160 extensive/transtensive corridor located between the morphotectonic

  11. SELECTED CHEMICAL ANALYSES AND GEOTHERMOMETRY OF HOT SPRING WATERS FROM THE CALABOZOS CALDERA, CENTRAL CHILE.

    USGS Publications Warehouse

    Thompson, J.M.; Grunder, A.L.; Hildreth, Wes

    1983-01-01

    Hot springs discharging from the active hydrothermal system associated with the Calabozos caldera, Chile, have measured orifice temperatures as high as 98. 5 degree C and calculated geothermometer temperatures as high as 250 degree C. Three types of spring waters can be identified from the chemical analyses: a Na-Cl type, a Na-HCO//3 type and a Na-mixed anion type. Chloride-enthalpy relations indicate that the hydrothermal reservoir water may attain temperatures near 342 degree C and that most spring waters are mixed with cold meteoric water. Despite the proximity of Mesozoic marine gypsum deposits, the Cl/Br weight ratio of the Calabozos spring waters does not appear to indicate that these waters have a significant 'marine' signature. Refs.

  12. Central Andes mountains, Chile/Argentina as seen from STS-67

    NASA Technical Reports Server (NTRS)

    1995-01-01

    The Chilean coastline and the arid Atacama Desert stretch the length of the view with the high Andes on the eastern margin where hundreds of volcanoes dot the landscape. The wider (250-350 kilometers) Altiplano ('plains') sector of the Andes appears in the top half of the view, and the narrow (120 kilometers) 'mountain-chain-dominated' sector to the bottom. The northern half of Chile can be seen, with the 'hammer-head' peninsula at the city of Antofagasta, top left. Up welling of cold water as the Humboldt Current immediately offshore gives rise to low stratus cloud. The extensive cloud mass on the right lies beyond the Andes in the low country of Argentina's 'pampas' grasslands and Chaco semi-desert.

  13. Association of Kawasaki disease with tropospheric winds in Central Chile: is wind-borne desert dust a risk factor?

    PubMed

    Jorquera, Héctor; Borzutzky, Arturo; Hoyos-Bachiloglu, Rodrigo; García, Alvaro

    2015-05-01

    It has been found that Kawasaki disease (KD) cases diagnosed in Japan, Hawaii and San Diego, USA increase when tropospheric wind patterns arrive from central Asia, suggesting a common, wind-borne causal agent. We analyzed KD cases hospitalized in Santiago, Chile to look for associations with local, regional and large scale meteorological variables. We compiled monthly data of KD incidence rates, local meteorological variables, large scale wind patterns and several El Niño Southern Oscillation (ENSO) indices for 2001-2010; we considered standardized anomalies in all analyses and used linear time series models to account for data autocorrelation. We found that meteorological variables explain 38% of variance in KD rates. A unit increase in northerly wind at 3 lagged months, temperature at 1 and 3 lagged months and monthly change of ENSO 4 index are associated with changes in KD rates of 0.203 (95% CI 0.049-0.358), 0.181 (95% CI 0.014-0.347), 0.192 (95% CI 0.030-0.353) and -0.307 (95% CI -0.458-0.156), respectively. These results are robust when northerly wind level is changed or when a shorter period (2005-2010) is used to estimate model parameters. We found a statistical association of KD at Santiago, Chile with tropospheric, northerly wind patterns suggesting that dust transported from the Atacama Desert could include a causative agent. A novel result is that ENSO dynamics also explain part of KD variability with a decrease in KD when La Niña is dissipating or El Niño is on the rise; hence climate scale dynamics might be taken into account in future studies worldwide - at least as a potential explanatory variable that may confound KD seasonality on a global scale.

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

    NASA Astrophysics Data System (ADS)

    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

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

    NASA Astrophysics Data System (ADS)

    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.

  16. Lacustrine turbidites as a tool for quantitative earthquake reconstruction: New evidence for a variable rupture mode in south central Chile

    NASA Astrophysics Data System (ADS)

    Moernaut, Jasper; Daele, Maarten Van; Heirman, Katrien; Fontijn, Karen; Strasser, Michael; Pino, Mario; Urrutia, Roberto; De Batist, Marc

    2014-03-01

    Understanding the long-term earthquake recurrence pattern at subduction zones requires continuous paleoseismic records with excellent temporal and spatial resolution and stable threshold conditions. South central Chilean lakes are typically characterized by laminated sediments providing a quasi-annual resolution. Our sedimentary data show that lacustrine turbidite sequences accurately reflect the historical record of large interplate earthquakes (among others the 2010 and 1960 events). Furthermore, we found that a turbidite's spatial extent and thickness are a function of the local seismic intensity and can be used for reconstructing paleo-intensities. Consequently, our multilake turbidite record aids in pinpointing magnitudes, rupture locations, and extent of past subduction earthquakes in south central Chile. Comparison of the lacustrine turbidite records with historical reports, a paleotsunami/subsidence record, and a marine megaturbidite record demonstrates that the Valdivia Segment is characterized by a variable rupture mode over the last 900 years including (i) full ruptures (Mw ~9.5: 1960, 1575, 1319 ± 9, 1127 ± 44), (ii) ruptures covering half of the Valdivia Segment (Mw ~9: 1837), and (iii) partial ruptures of much smaller coseismic slip and extent (Mw ~7.5-8: 1737, 1466 ± 4). Also, distant or smaller local earthquakes can leave a specific sedimentary imprint which may resolve subtle differences in seismic intensity values. For instance, the 2010 event at the Maule Segment produced higher seismic intensities toward southeastern localities compared to previous megathrust ruptures of similar size and extent near Concepción.

  17. Net Late Holocene emergence despite earthquake-induced submergence, south-central Chile

    USGS Publications Warehouse

    Atwater, B.F.; Nunez, H.J.; Vita-Finzi, C.

    1992-01-01

    Intertidal deposits show net Late Holocene emergence at three sites along the Pacific coast near Maulli??n and Carelmapu, Chile (latitude 41.6-41.7??S.). The maximum amount of net emergence is ca. 1 m in the past 1500 years and ca. 2 1 2 m in the past 4000 years. Emergence probably would have prevailed at a fourth site near Maulli??n were the site not underlain by easily compacted deposits; this site shows slight (< 1 m) net submergence in the past 3000 years. Despite net emergence, all four sites underwent 1-2 m of submergence from tectonic subsidence during a magnitude-9.5 earthquake in 1960, and two of the sites show evidence for earlier submergence events of Late Holocene age. The net emergence is probably due to some combination of cyclic uplift from elastic strain accumulation between earthquakes and monotonic uplift from postglacial loading of the Pacific Ocean floor. The small amount of the net emergence shows that neotectonics has had little net impact on Holocene relative sea level in part of the focal region of the largest earthquake recorded by seismograph. ?? 1992.

  18. Organophosphate Resistance and its Main Mechanism in Populations of Codling Moth (Lepidoptera: Tortricidae) from Central Chile.

    PubMed

    Reyes, Maritza; Barros-Parada, Wilson; Ramírez, Claudio C; Fuentes-Contreras, Eduardo

    2015-02-01

    The codling moth, Cydia pomonella (L.), is the key pest of apple production worldwide. Insecticide resistance has been reported in all producing countries, based on five different mechanisms. Codling moth in Chile has resistance to azinphos-methyl and tebufenozide in post-diapausing larvae. However, there are no studies about the susceptibility of these populations to insecticides from other chemical groups. Therefore, the efficacy of azinphos-methyl, chlorpyrifos-ethyl, esfenvalerate, methoxyfenozide, tebufenozide, and thiacloprid on neonate and post-diapausing larvae from six field populations was investigated, and identified resistance mechanisms in this species were evaluated. Neonate larvae were susceptible to all insecticides studied, but post-diapausing larvae from four populations were resistant to chlorpyrifos, one of them was also resistant to azinphos-methyl, and another one was resistant to tebufenozide. The acetylcholinesterase insensitivity mutation was not detected, and the sodium channel knockdown resistance mutation was present in a low frequency in one population. Detoxifying enzymatic activity of glutathione S-transferases, esterases, and cytochrome P-450 monooxygenases in adults differed among populations, but chlorpyrifos resistance was associated only with a decreased esterase activity as shown by a significant negative correlation between chlorpyrifos mortality and esterase activity. PMID:26470131

  19. Organophosphate Resistance and its Main Mechanism in Populations of Codling Moth (Lepidoptera: Tortricidae) from Central Chile.

    PubMed

    Reyes, Maritza; Barros-Parada, Wilson; Ramírez, Claudio C; Fuentes-Contreras, Eduardo

    2015-02-01

    The codling moth, Cydia pomonella (L.), is the key pest of apple production worldwide. Insecticide resistance has been reported in all producing countries, based on five different mechanisms. Codling moth in Chile has resistance to azinphos-methyl and tebufenozide in post-diapausing larvae. However, there are no studies about the susceptibility of these populations to insecticides from other chemical groups. Therefore, the efficacy of azinphos-methyl, chlorpyrifos-ethyl, esfenvalerate, methoxyfenozide, tebufenozide, and thiacloprid on neonate and post-diapausing larvae from six field populations was investigated, and identified resistance mechanisms in this species were evaluated. Neonate larvae were susceptible to all insecticides studied, but post-diapausing larvae from four populations were resistant to chlorpyrifos, one of them was also resistant to azinphos-methyl, and another one was resistant to tebufenozide. The acetylcholinesterase insensitivity mutation was not detected, and the sodium channel knockdown resistance mutation was present in a low frequency in one population. Detoxifying enzymatic activity of glutathione S-transferases, esterases, and cytochrome P-450 monooxygenases in adults differed among populations, but chlorpyrifos resistance was associated only with a decreased esterase activity as shown by a significant negative correlation between chlorpyrifos mortality and esterase activity.

  20. The invasive species Ulex europaeus (Fabaceae) shows high dynamism in a fragmented landscape of south-central Chile.

    PubMed

    Altamirano, Adison; Cely, Jenny Paola; Etter, Andrés; Miranda, Alejandro; Fuentes-Ramirez, Andres; Acevedo, Patricio; Salas, Christian; Vargas, Rodrigo

    2016-08-01

    Ulex europaeus (gorse) is an invasive shrub deemed as one of the most invasive species in the world. U. europaeus is widely distributed in the south-central area of Chile, which is considered a world hotspot for biodiversity conservation. In addition to its negative effects on the biodiversity of natural ecosystems, U. europaeus is one of the most severe pests for agriculture and forestry. Despite its importance as an invasive species, U. europaeus has been little studied. Although information exists on the potential distribution of the species, the interaction of the invasion process with the spatial dynamic of the landscape and the landscape-scale factors that control the presence or absence of the species is still lacking. We studied the spatial and temporal dynamics of the landscape and how these relate to U. europaeus invasion in south-central Chile. We used supervised classification of satellite images to determine the spatial distribution of the species and other land covers for the years 1986 and 2003, analysing the transitions between the different land covers. We used logistic regression for modelling the increase, decrease and permanence of U. europaeus invasion considering landscape variables. Results showed that the species covers only around 1 % of the study area and showed a 42 % reduction in area for the studied period. However, U. europaeus was the cover type which presented the greatest dynamism in the landscape. We found a strong relationship between changes in land cover and the invasion process, especially connected with forest plantations of exotic species, which promotes the displacement of U. europaeus. The model of gorse cover increase presented the best performance, and the most important predictors were distance to seed source and landscape complexity index. Our model predicted high spread potential of U. europaeus in areas of high conservation value. We conclude that proper management for this invasive species must take into account

  1. Old transient landscapes and surface processes: Multiple cosmogenic nuclide and sediment yield data from the Central Andes of northern Chile

    NASA Astrophysics Data System (ADS)

    Kober, F.; Ivy-Ochs, S.; Schlunegger, F.; Zeilinger, G.; Kubik, P. W.; Baur, H.; Wieler, R.

    2005-12-01

    The desert parts of the Andes of northern Chile are regarded as being one of the oldest landscapes on Earth and hence landscape forming processes must act at very slow rates. These slow rates have promoted controversial ideas on the evolution of the Andean mountain chain and discussions whether climatic or tectonic forces predominate the geodynamic evolution of the Andes. Here we present erosion rates of hillslope interfluves across the slope of the western Central Andes (Arica area, northern Chile) derived from several long-lived terrestrial cosmogenic nuclides (10Be, 21Ne, 26Al). Erosion rates positively correlate with elevation and the historical precipitation record, suggesting a coupling between climate and erosion. In addition, it is suggested that the very old landscapes could be preserved in the western Central Andes thanks to low tectonic activity and the prevailing dry climate. Erosion rates estimated back into the middle to late Miocene are on the order of 10-100cm/My at the hyperarid Western Escarpment (Atacama Desert) and the Costal Cordillera. In contrast, erosion rates for the semiarid Western Cordillera are up to >3000cm/My, at least back into the Holocene/late Pleistocene. Here sediment yield data obtained on a decadal scale indicate denudation rates of a similar order of magnitude. In comparison, erosion rates obtained from long-lived cosmogenic nuclides on hillsope interfluves for the Western Cordillera and those derived from preliminary data (21Ne) on catchment wide erosion rates of the Lluta-drainage system yield similar orders of magnitudes. Additionally, catchment wide erosion rates remain largely constant throughout the entire catchment. The analyses of multiple terrestrial cosmogenic nuclides and the use of various "erosion-island" diagrams allowed the identification of system states and of possible complex exposure histories. Complex exposure was identified for non-bedrock samples, such as boulders or amalgamated clast samples. Cosmogenic

  2. An integrated framework to assess adaptation options to climate change impacts in an irrigated basin in Central North Chile

    NASA Astrophysics Data System (ADS)

    Vicuna, S.; Melo, O.; Meza, F. J.; Alvarez, P.; Maureira, F.; Sanchez, A.; Tapia, A.; Cortes, M.; Dale, L. L.

    2013-12-01

    Future climate conditions could potentially affect water supply and demand on water basins throughout the world but especially on snowmelt-driven agriculture oriented basins that can be found throughout central Chile. Increasing temperature and reducing precipitation will affect both the magnitude and timing of water supply this part of the world. Different adaptation strategies could be implemented to reduce the impacts of such scenarios. Some could be incorporated as planned policies decided at the basin or Water Use Organization levels. Examples include changing large scale irrigation infrastructure (reservoirs and main channels) either physically or its operation. Complementing these strategies it is reasonable to think that at a disaggregated level, farmers would also react (adapt) to these new conditions using a mix of options to either modify their patterns of consumption (irrigation efficiency, crop mix, crop area reduction), increase their ability to access new sources of water (groundwater, water markets) or finally compensate their expected losses (insurance). We present a modeling framework developed to represent these issues using as a case study the Limarí basin located in Central Chile. This basin is a renowned example of how the development of reservoirs and irrigation infrastructure can reduce climate vulnerabilities allowing the economic development of a basin. Farmers in this basin tackle climate variability by adopting different strategies that depend first on the reservoir water volume allocation rule, on the type and size of investment they have at their farms and finally their potential access to water markets and other water supplies options. The framework developed can be used to study these strategies under current and future climate scenarios. The cornerstone of the framework is an hydrology and water resources model developed on the WEAP platform. This model is able to reproduce the large scale hydrologic features of the basin such as

  3. Operational Constraints on Hydropeaking and its Effects on the Hydrologic and Thermal Regime of a River in Central Chile

    NASA Astrophysics Data System (ADS)

    Olivares, M. A.; Guzman, C.; Rossel, V.; De La Fuente, A.

    2013-12-01

    Hydropower accounts for about 44% of installed capacity in Chile's Central Interconnected System, which serves most of the Chilean population. Hydropower reservoir projects can affect ecosystems by changing the hydrologic regime and water quality. Given its volumen regulation capacity, low operation costs and fast response to demand fluctuations, reservoir hydropower plants commonly operate on a load-following or hydropeaking scheme. This short-term operational pattern produces alterations in the hydrologic regime downstream the reservoir. In the case of thermally stratified reservoirs, peaking operations can affect the thermal structure of the reservoir, as well as the thermal regime downstream. In this study, we assessed the subdaily hydrologic and thermal alteration donwstream of Rapel reservoir in Central Chile for alternative operational scenarios, including a base case and several scenarios involving minimum instream flow (Qmin) and maximum hourly ramping rates (ΔQmax). Scenarios were simulated for the stratification season of summer 2009-2012 in a grid-wide short-term economic dispatch model which prescribes hourly power production by every power plant on a weekly horizon. Power time series are then translated into time series of turbined flows at each hydropower plants. Indicators of subdaily hydrologic alteration (SDHA) were computed for every scenario. Additionally, turbined flows were used as input data for a three-dimensional hydrodynamic model (CWR-ELCOM) of the reservoir which simulated the vertical temperature profile in the reservoir and the outflow temperature. For the time series of outflow temperatures we computed several indicators of subdaily thermal alteration (SDTA). Operational constraints reduce the values of both SDHA and SDTA indicators with respect to the base case. When constraints are applied separately, the indicators of SDHA decrease as each type of constraint (Qmin or ΔQmax) becomes more stringent. However, ramping rate

  4. Short-term Hydropower Reservoir Operations in Chile's Central Interconnected System: Tradeoffs between Hydrologic Alteration and Economic Performance

    NASA Astrophysics Data System (ADS)

    Olivares, M. A.

    2011-12-01

    Hydropower accounts for about 50% of the installed capacity in Chile's Central Interconnected System (CIS) and new developments are envisioned in the near future. Large projects involving reservoirs are perceived negatively by the general public. In terms of operations, hydropower scheduling takes place at monthly, weekly, daily and hourly intervals, and operations at each level affect different environmental processes. Due to its ability to quickly and inexpensively respond to short-term changes in demand, hydropower reservoirs often are operated to provide power during periods of peak demand. This operational scheme, known as hydropeaking, changes the hydrologic regime by altering the rate and frequency of changes in flow magnitude on short time scales. To mitigate impacts on downstream ecosystems, operational constraints -typically minimum instream flows and maximum ramping rates- are imposed on hydropower plants. These operational restrictions limit reduce operational flexibility and can reduce the economic value of energy generation by imposing additional costs on the operation of interconnected power systems. Methods to predict the degree of hydrologic alteration rely on statistical analyses of instream flow time series. Typically, studies on hydrologic alteration use historical operational records for comparison between pre- and post-dam conditions. Efforts to assess hydrologic alteration based on future operational schemes of reservoirs are scarce. This study couples two existing models: a mid-term operations planning and a short-term economic dispatch to simulate short-term hydropower reservoir operations under different future scenarios. Scenarios of possible future configurations of the Chilean CIS are defined with emphasis on the introduction of non-conventional renewables (particularly wind energy) and large hydropower projects in Patagonia. Both models try to reproduce the actual decision making process in the Chilean Central Interconnected System

  5. Characterization of copper-resistant bacteria and bacterial communities from copper-polluted agricultural soils of central Chile

    PubMed Central

    2012-01-01

    Background Copper mining has led to Cu pollution in agricultural soils. In this report, the effects of Cu pollution on bacterial communities of agricultural soils from Valparaiso region, central Chile, were studied. Denaturing gradient gel electrophoresis (DGGE) of the 16S rRNA genes was used for the characterization of bacterial communities from Cu-polluted and non-polluted soils. Cu-resistant bacterial strains were isolated from Cu-polluted soils and characterized. Results DGGE showed a similar high number of bands and banding pattern of the bacterial communities from Cu-polluted and non-polluted soils. The presence of copA genes encoding the multi-copper oxidase that confers Cu-resistance in bacteria was detected by PCR in metagenomic DNA from the three Cu-polluted soils, but not in the non-polluted soil. The number of Cu-tolerant heterotrophic cultivable bacteria was significantly higher in Cu-polluted soils than in the non-polluted soil. Ninety two Cu-resistant bacterial strains were isolated from three Cu-polluted agricultural soils. Five isolated strains showed high resistance to copper (MIC ranged from 3.1 to 4.7 mM) and also resistance to other heavy metals. 16S rRNA gene sequence analyses indicate that these isolates belong to the genera Sphingomonas, Stenotrophomonas and Arthrobacter. The Sphingomonas sp. strains O12, A32 and A55 and Stenotrophomonas sp. C21 possess plasmids containing the Cu-resistance copA genes. Arthrobacter sp. O4 possesses the copA gene, but plasmids were not detected in this strain. The amino acid sequences of CopA from Sphingomonas isolates (O12, A32 and A55), Stenotrophomonas strain (C21) and Arthrobacter strain (O4) are closely related to CopA from Sphingomonas, Stenotrophomonas and Arthrobacter strains, respectively. Conclusions This study suggests that bacterial communities of agricultural soils from central Chile exposed to long-term Cu-pollution have been adapted by acquiring Cu genetic determinants. Five bacterial isolates

  6. The invasive species Ulex europaeus (Fabaceae) shows high dynamism in a fragmented landscape of south-central Chile.

    PubMed

    Altamirano, Adison; Cely, Jenny Paola; Etter, Andrés; Miranda, Alejandro; Fuentes-Ramirez, Andres; Acevedo, Patricio; Salas, Christian; Vargas, Rodrigo

    2016-08-01

    Ulex europaeus (gorse) is an invasive shrub deemed as one of the most invasive species in the world. U. europaeus is widely distributed in the south-central area of Chile, which is considered a world hotspot for biodiversity conservation. In addition to its negative effects on the biodiversity of natural ecosystems, U. europaeus is one of the most severe pests for agriculture and forestry. Despite its importance as an invasive species, U. europaeus has been little studied. Although information exists on the potential distribution of the species, the interaction of the invasion process with the spatial dynamic of the landscape and the landscape-scale factors that control the presence or absence of the species is still lacking. We studied the spatial and temporal dynamics of the landscape and how these relate to U. europaeus invasion in south-central Chile. We used supervised classification of satellite images to determine the spatial distribution of the species and other land covers for the years 1986 and 2003, analysing the transitions between the different land covers. We used logistic regression for modelling the increase, decrease and permanence of U. europaeus invasion considering landscape variables. Results showed that the species covers only around 1 % of the study area and showed a 42 % reduction in area for the studied period. However, U. europaeus was the cover type which presented the greatest dynamism in the landscape. We found a strong relationship between changes in land cover and the invasion process, especially connected with forest plantations of exotic species, which promotes the displacement of U. europaeus. The model of gorse cover increase presented the best performance, and the most important predictors were distance to seed source and landscape complexity index. Our model predicted high spread potential of U. europaeus in areas of high conservation value. We conclude that proper management for this invasive species must take into account

  7. The 2015 Illapel Earthquake, Central Chile, a Case of a Characteristic Earthquake?

    NASA Astrophysics Data System (ADS)

    Dahm, T.; Tilmann, F. J.; Zhang, Y.; Moreno, M.; Saul, J.; Eckelmann, F.; Palo, M.; Deng, Z.; Chen, K.; Baez, J. C.; Babeyko, A. Y.; Schurr, B.; Wang, R.; Oncken, O.

    2015-12-01

    On September 16, 2015, the Chilean margin experienced a great subduction megathrust earthquake. The MW=8.2 Illapel earthquake occurred in the Metropolitan segment north of where the Juan-Fernandez ridge meets the Chile trench and subduction style and geometry change. Combining GPS displacement measurements, InSAR interferograms, strong motion and broadband seismological waveforms, and high frequency (HF) teleseismic backprojection we derive a comprehensive description of the coseismic rupture. We further determine moment tensors and obtain accurate depth estimates for mostly offshore aftershock sequence by careful observations of teleseismic depth phases. The rupture nucleated near the coast but then propagated to the north and updip, with a circular geometry of diameter 100 km and a peak slip of ~6 m below the forearc. HF seismic radiation is mostly emitted downdip of the region of most intense slip, but unlike in most previous events the high frequency emitters do not track the whole rupture but are confined to a small region. The time evolution of HF seismic radiation also arrests earlier than the long period rupture evolution, indicating that the final phase of the rupture progressed more smoothly. The aftershocks, mostly plate interface events, extend significantly beyond the limits of the main rupture in both directions. In 1943, a comparable event struck the Illapel area. The similar extent of the aftershock zone and tsunami heights therefore make this part of the margin a candidate site for generating characteristic earthquakes. The approximate match of peak slip and accumulated slip deficit in the 72 years since the 1943 event also support this interpretation. However, the 1943 event appears to have had a shorter source time function and probably a smaller magnitude, pointing to differences in the detailed rupture evolution. The coupling is mostly close to fully locked in this area at least along the coast line but nevertheless the coseismic rupture is

  8. Genetic Diversity in Nothofagus alessandrii (Fagaceae), an Endangered Endemic Tree Species of the Coastal Maulino Forest of Central Chile

    PubMed Central

    Torres-Díaz, Cristian; Ruiz, Eduardo; González, Fidelina; Fuentes, Glenda; Cavieres, Lohengrin A.

    2007-01-01

    Background and Aims The endemic tree Nothofagus alessandrii (Fagaceae) has been historically restricted to the coastal range of Region VII of central Chile, and its forests have been increasingly destroyed and fragmented since the end of the 19th century. In this study, the patterns of within- and among-population genetic diversity in seven fragments of this endangered narrowly endemic tree were examined. Methods Allozyme electrophoresis of seven loci of N. alessandrii was used to estimate genetic diversity, genetic structure and gene flow. Key Results High levels of genetic diversity were found as shown by mean expected heterozygosity (He = 0·182 ± 0·034), percentage of polymorphic loci (Pp = 61·2 %), mean number of alleles per locus (A = 1·8) and mean number of alleles per polymorphic locus (Ap = 2·3). Genetic differentiation was also high (GST = 0·257 and Nm = 0·7). These values are high compared with more widespread congeneric species. Conclusions Despite its endemic status and restricted geographical range N. alessandrii showed high levels of genetic diversity. The observed patterns of diversity are explained in part by historical processes and more recent human fragmentation. PMID:17513870

  9. Community response of zooplankton to oceanographic changes (2002-2012) in the central/southern upwelling system of Chile

    NASA Astrophysics Data System (ADS)

    Medellín-Mora, Johanna; Escribano, Ruben; Schneider, Wolfgang

    2016-03-01

    A 10-year time series (2002-2012) at Station 18 off central/southern Chile allowed us to study variations in zooplankton along with interannual variability and trends in oceanographic conditions. We used an automated analysis program (ZooImage) to assess changes in the mesozooplankton size structure and the composition of the taxa throughout the entire community. Oceanographic conditions changed over the decade: the water column became less stratified, more saline, and colder; the mixed layer deepened; and the oxygen minimum zone became shallower during the second half of the time series (2008-2012) in comparison with the first period (2002-2007). Both the size structure and composition of the zooplankton were significantly associated with oceanographic changes. Taxonomic and size diversity of the zooplankton community increased to the more recent period. For the second period, small sized copepods (<1 mm) decreased in abundance, being replaced by larger sized (>1.5 mm) and medium size copepods (1-1.5 mm), whereas euphausiids, decapod larvae, appendicularian and ostracods increased their abundance during the second period. These findings indicated that the zooplankton community structure in this eastern boundary ecosystem was strongly influenced by variability of the upwelling process. Thus, climate-induced forcing of upwelling trends can alter the zooplankton community in this highly productive region with potential consequences for the ecosystem food web.

  10. Fossil beetle evidence for climatic change 18,000-10,000 years B.P. in south-central Chile

    USGS Publications Warehouse

    Hoganson, J.W.; Ashworth, A.C.

    1992-01-01

    Cold-adapted beetles colonized the lowlands of the Lake Region of south-central Chile following the retreat of glaciers from their maximum extent at about 19,500 yr B.P. The beetle fauna from 18,000 to 14,000 yr B.P. was characterized by species of moorland habitats. This fauna was species-poor compared to later faunas of the postglacial interval. By 14,000 yr B.P. arboreal species were replacing species of open habitats, reflecting a change toward a warmer climate. By about 12,500 yr B.P. fossil beetle assemblages consisted entirely of rain forest species. The fauna of the postglacial interval was about five times as species-rich as that of the glacial interval. The change in species composition and greater diversity of the beetle fauna was produced by an increase in mean annual temperature estimated to be about 4??-5??C. This was the last major climatic change to affect profoundly the biota of the middle latitudes of South America. The fossil beetle assemblages do not imply a reversal to a colder climate at the time of the European Younger Dryas interval between 11,000 and 10,000 yr B.P. ?? 1992.

  11. A Millenium of Great, and Perhaps Lesser, Earthquakes Recorded by Unusual Landslide and Tsunami Deposits in Chiloe, South-Central Chile

    NASA Astrophysics Data System (ADS)

    Cisternas, M.; Lagos, M.; Srinivasalu, S.

    2007-05-01

    A stratigraphic sequence at Cocotue Bay, Chiloe Is., south-central Chile, containing both earthquake-triggered debris flows and tsunami deposits, yields an earthquake history that likely includes the giant earthquakes and tsunamis inferred previously from a combination of geology, ecology, and written records in south-central Chile (AD ~1000, ~1300, 1575 and 1960). However, the Cocotue sequence also contains evidence for at least four additional earthquakes and tsunamis that are intermediate in age and perhaps lesser in size. The most recent of the additional earthquakes recorded at Cocotue probably corresponds to the poorly understood Chilean earthquake and associated trans-Pacific tsunami of 1837. The tsunami, though small on the Chilean coast, ran as high as 6 m in Hawaii and flooded fields in Japan. At Cocotue, the 1837 earthquake, like other three earlier events, is probably represented by both a debris-flow deposit and a tsunami deposit. To study the sedimentary record of intermediate and lesser events is important because this is the more probable kind of event to occur in the near future of south-central Chile. Research funded by Proyecto Fondecyt 1060227

  12. The nearshore zone during coastal upwelling: Daily variability and coupling between primary and secondary production off central Chile

    NASA Astrophysics Data System (ADS)

    Peterson, William T.; Arcos, Dagoberto F.; McManus, George B.; Dam, Hans; Bellantoni, Diane; Johnson, Thomas; Tiselius, Peter

    The nearshore region of central Chile is important for spawning of sardine ( Sardinops sagax) anchovy ( Engraulis ringens) and jack mackerel ( Trachurus murphyii) and the importance of fisheries for these species has led to an interest in factors controlling the area's productivity. We studied daily variations in productivity at a nearshore station (25m depth) off Dichato, Chile (36°30‧S) during January 1986 to understand how wind-driven variability in the hydrography is translated into pulses of primary and secondary production of the plankton. During the study period, we observed three complete cycles of upwelling favourable/unfavourable winds. Water column destratification, as indicated by the surface-to-bottom gradient of sigma-t, lagged the wind by about one day. During active upwelling, cold water (<11.5°C) of high nitrate and low oxygen concentration (20-25μM and 1-2ml 1 -1 respectively) was found near the surface. During subsequent relaxation of upwelling, the water column became stratified as temperature, oxygen and chlorophyll increased. The size and taxonomic composition of the phytoplankton varied from one event to the next. Over the course of the study, from 15-100% of the chlorophyll could pass a 20μm mesh screen. Chain-forming diatoms, microflagellates, and the autotrophic ciliate Mesodinium rubrum dominated the first, second and third events, respectively. In rank order of abundance, Paracalanus parvus, Centropages brachiatus, Oithona spp., Acartia tonsa, Oncaea spp., Calanoides patagoniensis and Calanus chilensis dominated the copepod community. Changes in abundance of most species did not closely follow the upwelling cycle. Possibly, vertical movements or other behavioural responses caused zooplankton distributions to be uncorrelated with movements of the surface Ekman layer. Fecundity of several of the important copepod species was measured using the egg ratio and bottle incubation techniques. Compared to values reported in the literature

  13. Climate change impact on hydroclimate regimes and extremes over Andean basins in the central-southern Chile

    NASA Astrophysics Data System (ADS)

    Bozkurt, Deniz; Rojas, Maisa; Valdivieso, Jonás; Falvey, Mark

    2015-04-01

    We have assessed the impact of projected increases in temperature and decreased precipitation on variability and potential changes in hydroclimate regimes and extremes over Andean basins in the central-southern Chile (~30-40S). The altitude of the southern Andes in the study area has an average altitude of 5000 m in the north that decreases to 3000 m at the southern edge. Climatically the region has a Mediterranean-like climate with mainly winter precipitation that gradually increases southwards, from around 300 mm/yr to 1000 mm/yr. The region is home to most of the population in Chile (~10 mil. inhabitants), it has fertile and productive agriculture land, as well as hydro-electrical power plants. During the 20th Century the region has experienced a decreasing precipitation trend imbedded in important interannual and decadal scale variability. We have used gridded observed daily precipitation and temperatures to drive and validate the VIC macro-scale model over the region of interest at 0.25 x 0.25 degree resolution. Historical (1960-2005) and projected (RCP8.5, 2006-2099) daily precipitation and temperatures from 28 CMIP5 models are adjusted via a transfer function based on the gridded observed daily precipitation and temperature data. Adjusted time series are then used to drive the VIC model in order to present climate change projections. The hydrological model simulations foresee that drying is robust in the models and total annual runoff will decrease in the future (40-45% by the end of the century). Center timing of runoff tends to shift to earlier days (3-5 weeks by the end of the century). In some areas over the Andes winter runoff is projected to increase due to upward movement of zero isotherm. Moreover, reductions in the amount of snowpack and accelerated snowmelt lead to more pronounced increase in winter evapotranspiration over the same areas. The simulated 12-months Standardized Runoff Index (SRI) clearly shows severe persistent hydrological droughts

  14. Tithonian age of dinosaur fossils in central Patagonian, Chile: U-Pb SHRIMP geochronology

    NASA Astrophysics Data System (ADS)

    Suárez, Manuel; De La Cruz, Rita; Fanning, Mark; Novas, Fernando; Salgado, Leonardo

    2015-12-01

    Three Tithonian concordant U-Pb SHRIMP zircon ages of 148.7 ± 1.4, 147.9 ± 1.5 and 147.0 ± 1.0 from tuffs intercalated in a clastic sedimentary succession with exceptional dinosaur bones including the new taxon Chilesaurus diegosuarezi gen. et sp. nov. exposed in central Chilean Patagonia (ca. 46°30'S) are reported herein. The fossiliferous beds accumulated in a synvolcanic fan delta reaching a shallow marine basin as indicated by glauconite present in some of the beds, and coeval with the beginning of the transgression of the Aysén Basin.

  15. Paleowetlands and regional climate change in the central Atacama Desert, northern Chile

    USGS Publications Warehouse

    Quade, Jay; Rech, Jason A.; Betancourt, Julio L.; Latorre, Claudio; Quade, Barbra; Rylander, Kate Aasen; Fisher, Timothy

    2008-01-01

    Widespread, organic-rich diatomaceous deposits are evidence for formerly wetter times along the margins of the central Atacama Desert, one of the driest places on Earth today. We mapped and dated these paleowetland deposits at three presently waterless locations near Salar de Punta Negra (24.5°S) on the western slope of the Andes. Elevated groundwater levels supported phreatic discharge into wetlands during two periods: 15,900 to ~ 13,800 and 12,700 to ~ 9700 cal yr BP. Dense concentrations of lithic artifacts testify to the presence of paleoindians around the wetlands late in the second wet phase (11,000?–9700 cal yr BP). Water tables dropped below the surface before 15,900 and since 8100 cal yr BP, and briefly between ~ 13,800 and 12,700 cal yr BP. This temporal pattern is repeated, with some slight differences, in rodent middens from the study area, in both paleowetland and rodent midden deposits north and south of the study area, and in lake level fluctuations on the adjacent Bolivian Altiplano. The regional synchroneity of these changes points to a strengthening of the South American Monsoon — which we term the "Central Andean Pluvial Event" — in two distinct intervals (15,900–13,800 and 12,700–9700 cal yr BP), probably induced by steepened SST gradients across the tropical Pacific (i.e., La Niña-like conditions).

  16. Active tectonics of the Atacama Basin area, northern Chile: Implications for distribution of convergence across the central Andes

    NASA Astrophysics Data System (ADS)

    Chuang, Yi-Rung; Lin, Yen-Sheng; Shyu, J. Bruce H.

    2013-04-01

    The central Andes in South America is formed as the Nazca plate subducts northeastward beneath the South American plate along the Peru-Chile trench, parallel to the coastline. It has been shown that the convergence rate between the two plates is ~70-80 mm/yr, and about 10-15 mm/yr of the convergence is absorbed in the sub-Andean belt, east of the active volcanic arc. However, the convergence in the forearc region is still not well constrained. In order to understand how much convergence is absorbed in the forearc region, we analyzed the active tectonic characteristics of the Atacama Basin, just west of the active volcanic arc. With the help of various remote sensing datasets such as 30-m and 90-m resolution digital elevation models (DEM) produced from SRTM data, thermal infrared radiometer (TIR) ASTER images, Landsat, and Google Earth images, we identified many N-S trending compressional structures around the Atacama Basin. The active structures are found mainly in the northern and southern part of the basin. The structures in the north deformed many volcanic rocks at the surface, such as ignimbrites and several lava flows. Structures may extend southward to San Pedro de Atacama, the largest town in the Atacama Basin, and produced tectonic scarps inside the town. River terraces also formed in the hanging-wall block of the structures, north of San Pedro. From field surveys, we measured the offset amount of the structures and collected volcanic rocks in order to constrain the age of the deformation. These results enabled us to calculate the long-term deformation rate of the structures. Our results indicate that the long-term slip rate of the structures in the southern part of the basin is quite low, in the order of 10-1 mm/yr. Furthermore, we obtained detailed topographic profiles across the structures. In the south, the profiles were surveyed by using real-time kinematic (RTK) GPS. Together with the attitudes of bedding planes, we constructed the subsurface geometry

  17. On the effect of operation of the hydropower plant on the water quality of Rapel reservoir, central Chile

    NASA Astrophysics Data System (ADS)

    Rossel, V.; De La Fuente, A.

    2013-12-01

    Eutrophication of lakes and reservoirs is a common problem in systems with high incoming loads of nutrients. The consequent algae bloom related to the eutrophication alters the water quality and generates an incompatibility with the tourist and recreational activities. This study is focused on Rapel reservoir: an old, dentritic and monomictic reservoir, located in central Chile (34°S, 71.6°W), that has experienced numerous algae bloom events in the past years produced by high loads of nutrients, sediments and metals. This reservoir was originally constructed in 1968 for hydropower generation without environmental restrictions on its operation. Rapel is part of Chile's Central Interconnected System (SIC), and is controlled by an independent system operator (ISO) that decides the optimal allocation of water by minimizing the SIC's operation cost. As a result of this framework, Rapel reservoir operates based on a hydropeaking scheme, thus producing energy few hours a day while zero outflows are observed the remaining hours, impacting on Rapel river located downstream the reservoir. However, previous research showed that this hydropeaking has important effects on the hydrodynamic of the reservoir as well. Particularly, it enhances vertical mixing nears the dam, and reduces horizontal dispersion. Furthermore, hydropeaking defines the outflows water temperature, and the temperature profile near the dam. As a consequence of this role of hydropeaking on the hydrodynamics and mixing of Rapel reservoir, it is expected to be a link between hydropeaking and water quality. The aim of the study is to evaluate the impact of the operation of hydropower plant on the water quality of Rapel reservoir, for which the reservoir system is modeled using the three dimensional hydrodynamic and water quality model ELCOM-CAEDYM. Field data to validate the results and to define boundary and initial conditions are available for the austral summer period of 2009-2010. Different scenarios of

  18. Ammonium Production off Central Chile (36°S) by Photodegradation of Phytoplankton-Derived and Marine Dissolved Organic Matter

    PubMed Central

    Rain-Franco, Angel; Muñoz, Claudia; Fernandez, Camila

    2014-01-01

    We investigated the production of ammonium by the photodegradation of dissolved organic matter (DOM) in the coastal upwelling system off central Chile (36°S). The mean penetration of solar radiation (Z1%) between April 2011 and February 2012 was 9.4 m, 4.4 m and 3.2 m for Photosynthetically Active Radiation (PAR; 400–700 nm), UV-A (320–400 nm) and UV-B (280–320 nm), respectively. Ammonium photoproduction experiments were carried out using exudates of DOM obtained from cultured diatom species (Chaetoceros muelleri and Thalassiosira minuscule) as well as natural marine DOM. Diatom exudates showed net photoproduction of ammonium under exposure to UVR with a mean rate of 0.56±0.4 µmol L−1 h−1 and a maximum rate of 1.49 µmol L−1 h−1. Results from natural marine DOM showed net photoproduction of ammonium under exposure to PAR+UVR ranging between 0.06 and 0.2 µmol L−1 h−1. We estimated the potential contribution of photochemical ammonium production for phytoplankton ammonium demand. Photoammonification of diatom exudates could support between 117 and 453% of spring-summer NH4+ assimilation, while rates obtained from natural samples could contribute to 50–178% of spring-summer phytoplankton NH4+ requirements. These results have implications for local N budgets, as photochemical ammonium production can occur year-round in the first meters of the euphotic zone that are impacted by full sunlight. PMID:24968138

  19. Degradation capability of the coastal environment adjacent to the Itata River in central Chile (36.5° S)

    NASA Astrophysics Data System (ADS)

    Pantoja, S.; Gutiérrez, M. H.; Ampuero, P.; Tejos, E.

    2011-08-01

    The response of the coastal ocean influenced by both river discharges and inputs of photosynthetically derived organic carbon product of upwelling, was evaluated by estimating rates of microbial hydrolysis of macromolecules with the goal of estimating the potential degradation capability of the coastal ecosystem off central Chile. Extracellular enzymatic activity (EEA) in seawater was dominated by aminopeptidase activity on substrate L-leucine-4-methyl-7-coumarinylamide (MCA-leu) (1.2 to 182 nmol l-1 h-1) followed by 4-methylumbelliferyl-ß-D-glucoside (MUF-glu) (0.08-61 nmol l-1 h-1) and 4-methylumbelliferyl-ß-D-cellobiose (MUF-cel) (0.15-7 nmol l-1 h-1), with the highest rates measured during spring-summer. In riverine waters, extracellular enzymatic hydrolysis remained within the range of 45 to 131 nmol l-1 h-1 for MCA-leu and ca. 20 nmol l-1 h-1 for glucosidic substrates, year-round. Contrary to the EEA observed for the marine water column, surface sediment extracellular enzymatic hydrolysis of MCA-leu (0.04 to 6.13 nmol g-1 dw h-1) was in the same order of magnitude as the rates observed for MUF-cel (0.004 to 5.1 nmol g-1 dw h-1) and MUF-glu (0.007 to 10.5 nmol g-1 dw h-1). Moreover, hydrolysis in sediments was characterized by higher rates during winter compared with spring-summer in the coastal and estuarine zone. The five years of data allowed us to evaluate the potential capability of microbial processing of organic carbon in the coastal area adjacent to the Itata river discharge where the increase in primary production in the productive seasons is accompanied by the increase in hydrolysis of macromolecules.

  20. Degradation capability of the coastal environment adjacent to the Itata River in central Chile (36.5° S)

    NASA Astrophysics Data System (ADS)

    Pantoja, S.; Gutiérrez, M. H.; Ampuero, P.; Tejos, E.

    2011-02-01

    The response of the coastal ocean influenced by both river discharges and inputs of photosynthetically derived organic carbon product of upwelling, was evaluated by estimating rates of microbial hydrolysis of macromolecules with the goal of estimating the degradation capability of the coastal ecosystem off central Chile. Extracellular enzymatic hydrolysis in seawater was dominated by aminopeptidase activity on substrate MCA-leu (1.2 to 182 nM h-1), which surpassed that of substrates MUF-glu (0.08-61 nM h-1) and MUF-cel (0.15-6.8 nM h-1), with the fastest rates measured during spring-summer. In riverine waters, extracellular enzymatic hydrolysis remained within the range of 45 to 131 nM h-1 for MCA-leu and ca. 20 nM h-1 for glucosidic substrates, year-round. Contrary to the observed for the marine water column, surface sediment extracellular enzymatic hydrolysis of MCA-leu (0.04 to 6.13 nmol gdw-1 h-1) was in the same order of magnitude as the rates observed for MUF-cel (0.004 to 2.58 nmol gdw-1 h-1) and MUF-glu (0.007 to 10.5 nmol gdw-1 h-1). Moreover, hydrolysis was characterized by higher rates during winter compared with spring-summer in the coastal and estuarine zone. The five years of data allowed us to construct a carbon budget for winter and spring-summer in the coastal area adjacent to the Itata River discharge. The comparison of fluxes evidenced a deficit of photosynthetic carbon to fuel extracellular hydrolysis in the water column during both periods (winter 20% and spring-summer 35%). We estimated that the Itata River is a feasible source of dissolved organic carbon, specially during winter, in the form of macromolecules, although non-focal sources may be also significant for the area.

  1. Temporal variability and phylogenetic characterization of planktonic anammox bacteria in the coastal upwelling ecosystem off central Chile

    NASA Astrophysics Data System (ADS)

    Galán, Alexander; Molina, Verónica; Belmar, Lucy; Ulloa, Osvaldo

    2012-01-01

    The phylogenetic affiliation and temporal variability in the abundance of planktonic anammox bacteria were studied at a time-series station above the continental shelf off central Chile (∼36°S; bottom depth 93 m), a wind-driven, seasonal upwelling area, between August 2006 and April 2008. The study was carried out by cloning and sequencing the 16S rRNA gene and by using catalyzed reporter deposition-fluorescence in situ hybridization (CARD-FISH). Our results showed the presence of a single anammox bacteria-like ribotype during both upwelling and non-upwelling seasons, which was phylogenetically associated with a recently described oxygen-minimum-zone subcluster within the Candidatus Scalindua clade. Moreover, clear differences were observed in the temporal and vertical distribution of anammox cells. During the upwelling season (austral spring-summer), relatively high abundances (∼5500 cells mL -1) and large cells (0.8 μm 3-75.7 fg C cell -1) were found below 20 m depth. In contrast, during the non-upwelling season (austral fall-winter), lower abundances (∼600 cells mL -1) and smaller cells (0.1 μm 3-22.8 fg C cell -1) were found, predominantly associated with the bottom layer. Overall, our results indicate that the abundance and vertical distribution of anammox planktonic assemblages are related to the occurrence of seasonal, wind-driven, coastal upwelling, which in turn appears to offer favorable conditions for the development of these microorganisms. The dominance of a unique anammox bacteria-like ribotype could be related to the high environmental variability observed in the system, which prevents the establishment of other anammox lineages.

  2. Pyruvate Oxidoreductases Involved in Glycolytic Anaerobic Metabolism of Polychaetes from the Continental Shelf off Central-South Chile

    NASA Astrophysics Data System (ADS)

    González, R. R.; Quiñones, R. A.

    2000-10-01

    The presence of low oxygen conditions in extensive areas of the continental shelf off central-south Chile has important effects on the biochemical adaptations of the organisms living in this ecosystem. Polychaetes assemblages cohabit on the shelf with an extensively distributed prokaryotic community made up of giant filamentous sulfur bacteria (mainly Thioploca sp.). The aim of this research was to characterize the pyruvate oxidoreductases enzymes involved in the biochemical adaptation of these benthic polychaetes. Nine polychaete species ( Paraprionospio pinnata, Nephtys ferruginea, Glycera americana, Haploscoloplos sp., Lumbrineris composita, Sigambra bassi, Aricidea pigmentata , Cossura chilensis, and Pectinaria chilensis) were assayed for lactic dehydrogenase (LDH), octopine dehydrogenase (OPDH), strombine dehydrogenase (STRDH) and alanopine dehydrogenase (ALPDH). Each species had a characteristic number of the pyruvate oxidoreductases assayed ranging from 4 in Paraprionospio pinnata to 1 in Pectinaria chilensis . The pyruvate saturation curves obtained for the enzymes from all species analysed, except L. composita, suggest that NADH can be oxidized at different rates depending on the amino acid used in the reaction with pyruvate. Our results indicate that organisms having more that one pyruvate oxidoreductase present a greater metabolic capacity to cope with functional and environmental hypoxia because these enzymes would better regulate the pyruvate consumption rate during the transition period. Thus, the dominance of Paraprionospio pinnata in the study area and its worldwide distribution is consistent with its higher number of pyruvate oxidoreductases with different pyruvate consumption rates involved in anaerobic metabolism. Finally, a positive allometric relationship was found between body size and the specific activity of ALPDH, STRDH, and maximum pyruvate oxidoreductase specific activity. This latter result suggests a positive scaling of the specific

  3. A time series of prokaryote secondary production in the oxygen minimum zone of the Humboldt current system, off central Chile

    NASA Astrophysics Data System (ADS)

    Levipan, H. A.; Quiñones, R. A.; Urrutia, H.

    2007-11-01

    Because the marine picoplanktonic communities are made up of phylogenetically different microbial groups, the re-evaluation of key processes such as bacterial secondary production (BSP) has become an important contemporary issue. The difficulty of differentiating the metabolic processes of Bacteria from the rest of the microorganisms in the water column (i.e., Archaea and Eukarya) has made it difficult to estimate in situ BSP. This work presents the seasonal variability of the prokaryote secondary production (PSP) measured by the incorporation of 14C-leucine in the oxygen minimum zone (OMZ) off central-southern Chile. The BSP and potential archaeal secondary production (PASP) were determined through the combined use of 14C-leucine and N1-guanyl-1, 7-diaminoheptane (GC 7), an efficient inhibitor of archaeal and eukaryote cell growth. BSP accounted for the majority of the PSP (total average, 59 ± 7.5%); maximum values were ∼600 μg C m -3 h -1 and, on several dates, BSP represented 100% of the PSP. Similarly, PASP was also an important fraction of the PSP (total average, 42.4 ± 8.5%), although with levels that ranged from not detectable (on given dates) to levels that represented up to ∼97% of PSP (winter 2003). Our results showed that both Bacteria and Archaea accounted for almost equal portions of the prokaryote heterotrophic metabolism in the OMZ, and that PASP is notoriously enhanced through temporal pulses of heterotrophy. This indicates that, at least in marine systems with high abundance of Archaea (e.g., mesopelagic realm), the secondary production obtained through methods measuring the uptake of radiolabeled substrates should be considered as PSP and not as BSP. If the latter is the target measurement, then the use of an inhibitor of both archaeal and eukaryote cell growth such as GC 7 is recommended.

  4. Flat vs. Normal subduction, Central Chile: insights from regional seismic tomography and rock type modeling

    NASA Astrophysics Data System (ADS)

    Marot, Marianne; Monfret, Tony; Gerbault, Muriel; Nolet, Guust; Ranalli, Giorgio; Pardo, Mario

    2013-04-01

    The Central Chilean subduction zone (27-35°S) is host to a multitude of unexplained phenomena, all likely linked to one another. Here, the 35 Ma oceanic Nazca plate is subducting beneath South America with a well developed, highly seismic flat slab, very well correlated with the subducting Juan Fernandez seamount Ridge (JFR) track, and also with the absence of volcanism at the surface. The upper plate, currently under compression, is composed of a series of accreted terranes of various origins and ages. Although no general consensus on the formation of this flat slab has been yet achieved, there may have been influence of overthickened oceanic crust, delayed eclogitization and consequent fluid retain within the slab, and slab suction due to the high convergence rate with the thick Rio de Plata craton. Therefore, the main questions we address are: Does the slab dehydrate along the flat subducting segment? If so, how hydrated is the slab, at what depth does slab dehydration occur, where are the fluids transported to, and where are they stored? Is magmatism still active beneath the now inactive arc? Are accreted terranes and suture zones important attributes of this subduction zone? Do they possess their own mantle entities? To answer these questions, we analyzed recorded local seismicity and performed regional 3D seismic tomography for Vp and Vs. Combining seismic tomography with 2D instantaneous thermo-mechanical modeling for the regions of flat and normal subduction, we predict rock compositions for these two regions based on published mineral and rock elastic properties. Here, we present a comparison between the normal subduction zone to the south, reflecting typical and expected features, and the flat slab region to the north, exhibiting heterogeneities. Our results agree with other studies for a dry and cold continental mantle above the flat slab. We distinguish the Cuyania terrane with overthickened crust and/or abnormal mantle beneath it. We notice that the

  5. Effects of seasonal variability in across- and alongshore transport of anchoveta ( Engraulis ringens) larvae on model-based pre-recruitment indices off central Chile

    NASA Astrophysics Data System (ADS)

    Parada, Carolina; Colas, Francois; Soto-Mendoza, Samuel; Castro, Leonardo

    2012-01-01

    An individual-based model (IBM) of anchoveta ( Engraulis ringens) larvae was coupled to a climatological hydrodynamic (Regional Oceanic Modeling System, ROMS) model for central-southern Chile to answer the question as to whether or not across- and alongshore transport off central-southern Chile enhances retention in the spawning areas during the winter and summer reproductive periods, using model-based pre-recruitment indices (simulated transport success to nursery areas). The hydrodynamic model validation showed that ROMS captures the mean Seas Surface Temperature and Eddie Kinetic Energy observed in satellite-based data over the entire region. The IBM was used to simulate the transport of eggs and larvae from spawning zones in central Chile (Constitución, Dichato, Gulf of Arauco and Lebu-Corral) to historical nursery areas (HRZ, region between 35°S and 37°S). Model results corroborated HRZ as the most successful pre-recruitment zone (particles originated in the Dichato and Gulf of Arauco spawning areas), as well as identifying Lebu-Corral as a zone of high retention with a high associated pre-recruitment index (particles originated in the Lebu-Corral spawning zone). The highest pre-recruitment values were mainly found in winter. The Constitución and Dichato spawning zones displayed a typical summer upwelling velocity pattern, while the Gulf of Arauco in summertime showed strong offshore and alongshore velocity components. The Lebu-Corral region in winter presented important near-surface cross-shore transport towards the coast (associated with downwelling events), this might be one of the major mechanisms leading to high retention levels and a high pre-recruitment index for Lebu-Corral spawning zone. The limitations of the modeling approach are discussed and put into perspective for future work.

  6. Combined impact of ocean acidification and corrosive waters in a river-influenced coastal upwelling area off Central Chile

    NASA Astrophysics Data System (ADS)

    Vargas, C.; De La Hoz, M.; San Martin, V.; Contreras, P.; Navarro, J. M.; Lagos, N. A.; Lardies, M.; Manríquez, P. H.; Torres, R.

    2012-12-01

    Elevated CO2 in the atmosphere promotes a cascade of physical and chemical changes affecting all levels of biological organization, and the evidence from local to global scales has shown that such anthropogenic climate change has triggered significant responses in the Earth's biota. The increased concentration of CO2 is likely to cause a corresponding increase in ocean acidification (OA). In addition, economically valuable shellfish species predominantly inhabit coastal regions both in natural stocks and/or in managed stocks and farming areas. Many coastal ecosystems may experience seawater pCO2 levels significantly higher than expected from equilibrium with the atmosphere, which in this case are strongly linked to biological processes and/or the impact of two important processes; river plumes and coastal upwelling events, which indeed interplay in a very dynamic way on continental shelves, resulting in both source or sink of CO2 to the atmosphere. Coastal ecosystems receive persistent acid inputs as a result of freshwater discharges from river basins into the coastal domain. In this context, since shellfish resources and shellfish aquaculture activities predominantly occur in nearshore areas, it is expected that shellfish species inhabiting river-influenced benthic ecosystems will be exposed persistently to acidic conditions that are suboptimal for its development. In a wider ecological context, little is also known about the potential impacts of acid waters on the performance of larvae and juveniles of almost all the marine species inhabiting this benthic ecosystem in Eastern Southern Pacific Ocean. We present here the main results of a research study aimed to investigate the environmental conditions to which economically valuable calcifiers shellfish species are exposed in a river-influenced continental shelf off Central Chile. By using isotopic measurements in the dissolved inorganic carbon (DIC) pool (d13C-DIC) we showed the effect of the remineralization of

  7. Temporal and spatial distribution of floating objects in coastal waters of central-southern Chile and Patagonian fjords

    NASA Astrophysics Data System (ADS)

    Hinojosa, Iván A.; Rivadeneira, Marcelo M.; Thiel, Martin

    2011-03-01

    Floating objects are suggested to be the principal vector for the transport and dispersal of marine invertebrates with direct development as well as catalysts for carbon and nutrient recycling in accumulation areas. The first step in identifying the ecological relevance of floating objects in a specific area is to identify their spatio-temporal distribution. We evaluated the composition, abundance, distribution, and temporal variability of floating objects along the continental coast of central-southern Chile (33-42°S) and the Patagonian fjords (42-50°S) using ship surveys conducted in austral winter (July/August) and spring (November) of the years 2002-2005 and 2008. Potential sources of floating items were identified with the aid of publicly available databases and scientific reports. We found three main types of floating objects, namely floating marine debris (mainly plastic objects and Styrofoam), wood (trunks and branches), and floating kelps ( Macrocystis pyrifera and Durvillaea antarctica). Floating marine debris were abundant along most of the examined transects, with markedly lower abundances toward the southern fjord areas. Floating marine debris abundances generally corresponded to the distribution of human activities, and were highest in the Interior Sea of Chiloé, where aquaculture activities are intense. Floating wood appeared sporadically in the study area, often close to the main rivers. In accordance with seasonal river run-off, wood was more abundant along the continental coast in winter (rainy season) and in the Patagonian fjords during the spring surveys (snow melt). Densities of the two floating kelp species were similar along the continental coast, without a clear seasonal pattern. M. pyrifera densities increased towards the south, peaking in the Patagonian fjords, where it was dominant over D. antarctica. Densities of M. pyrifera in the Patagonian fjords were highest in spring. Correlation analyses between the abundances of floating

  8. Chemosynthetic trophic support for the benthic community at an intertidal cold seep site at Mocha Island off central Chile

    NASA Astrophysics Data System (ADS)

    Sellanes, Javier; Zapata-Hernández, Germán; Pantoja, Silvio; Jessen, Gerdhard L.

    2011-12-01

    We analyzed C and N stable isotope ratios of benthic fauna and their potential food sources at an intertidal methane seep site and a control site without emanation at Mocha Island (central Chile). The objective was to trace the origin of the main food sources used by the local heterotrophic fauna, based on the hypothesis that chemosynthetic production could be partially fueling the local food web at the seep site. Food sources sampled at both sites included macroalgae, particulate organic matter and bacteria-like filaments found growing over the red algae Gelidium lingulatum within the areas of active methane release. At the control site, located 11 km away from the gas emanation, fauna exhibited moderate δ 13C values ranging from -16.2‰ (in a nereid polychaete) to -14.8‰ (in a cirolanid isopod), which were consistent with those of the potential photosynthetic food sources sampled at this site (-20.2 to -16.5‰). δ 13C values of the photosynthetic food sources at the seep site similarly ranged between -25.4 and -17.9‰. However, a portion of the animals at this site were consistently more 13C-depleted, with δ 13C values close to that of the seeping methane (-43.8‰) and the bacteria-like filaments (-39.2 ± 2.5‰) also collected at this site. Specific examples were the Marphysa sp. polychaetes (δ 13C = -44.7 ± 0.6‰), the Schistomeringos sp. dorvilleid polychaetes (δ 13C = -42.9‰), and the tanaid crustacean Zeuxo marmoratus (δ 13C = -37.3 ± 0.2‰). The significantly higher δ 13C values of the herbivorous gastropod Tegula atra at the seep site (-29.3 ± 3.1‰) than at the control site (-12.6 ± 0.3‰) also indicated differences among sites of the preferred carbon sources of this species. Mixing model estimates indicate that at the seep site bacteria-like filaments could be contributing up to ˜60% of the assimilated diet of selected invertebrates. Furthermore, several indicators of trophic structure, based in isotopic niche metrics, indicate a

  9. Constraining the magma flow record based on magmatic and magnetic data in La Gloria Pluton, central Chile

    NASA Astrophysics Data System (ADS)

    Gutierrez, F. J.; Payacán, I.; Gelman, S. E.; Bachmann, O.; Creative Physical Petrology Team

    2013-05-01

    The magmatic origin of the anisotropy of magnetic susceptibility (AMS) is examined in comparison with magmatic anisotropy data in a small, shallow, silicic magma reservoir in the upper crust. La Gloria Pluton (LGP) is a 10 Ma granodiorite/quartz monzonite of about 250 km3 located in the southern Andes, central Chile. LGP represents a particularly simple case of a silicic intrusion that was assembled in only a few pulses and cooled over a short time interval. Hornblende, biotite and minor magnetite are ubiquitous mafic phases. The AMS tensor indicates that magnetic fabric has an oblate shape (i.e. magnetic foliation is higher than magnetic lineation). Lineations are weak (values up to 1.05), have a N-NW trend with a nearly horizontal dip and are interpreted to represent axisymmetric convection parallel to the main pluton elongation. Foliations are more pronounced (values up to 1.14), having NW trends and dips that vary gradually from vertical at the walls, to horizontal at the center and near the roof of the chamber. We selected 12 samples from AMS sites to obtain petrographic data (well-distributed throughout the pluton, containing samples from the walls, the center and the roof of LGP), and then, determine the magmatic fabric (anisotropy, lineation, foliation). We made 3 oriented thin sections per sample oriented with the AMS. Magmatic anisotropy data were obtained by measuring mineral length, width and orientation in photomicrographs of the three main planes of the AMS tensor, producing 3-D mineral data which were collected for plagioclase and amphibole + bitotite independently. For each site, a Bingham distribution with 95% of confidence is used to determine the mean mineral orientations and their angle difference with the AMS axes. Magmatic anisotropy tensor and rotations with respect to the AMS tensor are determined using both eigenvalues and minimization algorithms. Preliminary results indicate that crystals are coherently oriented in both mineral groups, and

  10. Future Temperatures and Precipitations in the Arid Northern-Central Chile: A Multi-Model Downscaling Approach

    NASA Astrophysics Data System (ADS)

    Souvignet, M.; Heinrich, J.

    2010-03-01

    Downscaling of global climate outputs is necessary to transfer projections of potential climate change scenarios to local levels. This is of special interest to dry mountainous areas, which are particularly vulnerable to climate change due to risks of reduced freshwater availability. These areas play a key role for hydrology since they usually receive the highest local precipitation rates stored in form of snow and glaciers. In the central-northern Chile (Norte Chico, 26-33ºS), where agriculture still serves as a backbone of the economy as well as ensures the well being of people, the knowledge of water resources availability is essential. The region is characterised by a semiarid climate with a mean annual precipitation inferior to 100mm. Moreover, the local climate is also highly influenced by the ENSO phenomenon, which accounts for the strong inter-annual variability in precipitation patterns. Although historical and spatially extensive precipitation data in the headwaters of the basins in this region are not readily available, records at coastal stations show worrisome trends. For instance, the average precipitation in La Serena, the most important city located in the Coquimbo Region, has decreased dramatically in the past 100 years. The 30-year monthly average has decreased from 170 mm in the early 20th century to values less than 80 mm nowadays. Climate Change is expected to strengthen this pattern in the region, and therefore strongly influence local hydrological patterns. The objectives of this study are i) to develop climate change scenarios (2046-2099) for the Norte Chico using multi-model predictions in terms of temperatures and precipitations, and ii) to compare the efficiency of two downscaling techniques in arid mountainous regions. In addition, this study aims at iii) providing decision makers with sound analysis of potential impact of Climate Change on streamflow in the region. For the present study, future local climate scenarios were developed

  11. Mineralized and Barren Tourmaline Breccia at Río Blanco-Los Bronces Copper Deposit, Central Chile

    NASA Astrophysics Data System (ADS)

    Hohf, Michael; Seifert, Thomas; Ratschbacher, Lothar; Rabbia, Osvaldo; Krause, Joachim; Haser, Sabine; Cuadra, Patricio

    2014-05-01

    The Río Blanco-Los Bronces porphyry copper-molybdenum cluster (14.8-4.3 Ma) in central Chile is one of the largest mining districts of the world with more than 200 Mt of contained Cu; almost 30% of these resources are hosted by hydrothermal breccias. These breccia complexes are tourmaline-, biotite-, chlorite-, or iron oxide-cemented and are widespread in the Paleo-Eocene and Mio-Pliocene porphyry Cu-Mo belt of the central Andes. The ongoing research project aims to understand the time-space relationships between the different breccia bodies and the multiple porphyry intrusions. For this, two cross sections in the southern part of the deposit (Sur-Sur and La Americana areas) are studied. Most interesting from the economic/genetic point of view is the intermineral breccia (tourmaline- and biotite-cemented), which have high copper grades. It is under debate whether there is a vertical mineralogical zonation of the cement of the breccia body from tourmaline-rich at the top to biotite-dominated at the bottom, or there are two superimposed breccia formation events. Textural and mineralogical observations of benches- and tunnels-outcrops, drill cores, and polished-thin sections support the first hypothesis. Our work has been focused on tourmaline chemistry due to its high resistance to alteration and weathering, which allows this mineral to retain its original isotopic signature. Preliminary results of 127 microprobe measurements of tourmaline chemistry from the early mineralized breccia (BXT) and the late barren one (BXTTO) show that all the tourmalines belong to the alkali group and the composition ranges between the dravite-schorl end members. There is a pronounced negative correlation between Fe (ferric?) and Al, probably due to exchange at the Z octahedral position. The backscatter images of tourmaline show oscillatory and sector zonings, i.e., alternating light bands/zones (high CaO, FeO, Na2O) and darker ones (enriched in Al2O3 and MgO). There is no significant

  12. A study of the relationship between degree of ethnocentrism and typologies of food purchase in supermarkets in central-southern Chile.

    PubMed

    Schnettler, Berta; Miranda, Horacio; Lobos, Germán; Sepúlveda, José; Denegri, Marianela

    2011-06-01

    The objective of this study was to distinguish different types of consumers according to their level of ethnocentrism in relation to the consumption of foodstuffs in central-southern Chile. To do this a modification of the CETSCALE (Consumer Ethnocentric Tendencies Scale) was applied through direct survey of 800 habitual supermarket shoppers in two cities in central-southern Chile. The modified CETSCALE presented a sufficient level of internal consistency and there were three factors which included the 17 items of the scale. Five typologies of consumer with different degrees of ethnocentrism were distinguished by cluster analysis, based on the values of the factors and items in the CETSCALE. The composition of the typologies of consumers were related to the city and zone of residence, age, socioeconomic level, self-declared life-style, ethnic origin, knowledge of the origin of the foodstuffs purchased, frequency of purchase of imported foodstuffs and reasons for rejection in the case of a low purchase frequency. It may therefore be concluded that different levels of ethnocentrism exist in the consumption of foodstuffs, related with some socio-demographic characteristics of consumers and their attitudes to imported foodstuffs. PMID:21335039

  13. Landscape analysis of adult codling moth (Lepidoptera: Tortricidae) distribution and dispersal within typical agroecosystems dominated by apple production in central Chile.

    PubMed

    Basoalto, E; Miranda, M; Knight, A L; Fuentes-Contreras, E

    2010-10-01

    We analyzed the spatial distribution and dispersal of codling moth, Cydia pomonella (L.), adults within two heterogeneous agroecosystems typical of central Chile: commercial apple, Malus domestica Borkhausen, orchards surrounded by various unmanaged host plants. Both a geostatistical analysis of catches of adult males with a grid of sex pheromone-baited traps and an immunological self-marking technique combined with traps baited with a male and female attractant were used. The spatial analyses identified the key sources of moths within these diverse landscapes. Codling moth catches in traps were spatially associated within distances of ≈ 150-300 m. Similarly, the mean distance from the immunological self-marking plots within the commercial apple orchard to the traps that captured marked adults was 282 m. In contrast, the mean distance in the capture of marked moths from unmanaged self-marking plots to a commercial orchard was 828 m. These data suggest that the success of any future area-wide management programs for codling moth in Chilean pome fruit must include a component for managing or removing noncommercial hosts that surround orchards. This analysis also suggests that the selection pressure for resistance imposed by insecticide sprays within managed orchards is likely dampened by the influx of susceptible moths from unmanaged sites common in central Chile. PMID:22546434

  14. Analog Modeling of the Juan Fernández Ridge, Central Chile, and Implications for Flat-Slab Subduction Dynamics

    NASA Astrophysics Data System (ADS)

    Woodell, D.; Anderson, M. L.

    2009-12-01

    This study compares the strain experienced by the subducting lithosphere in analog models to the strain recorded by earthquakes in the subduction zone that includes the Juan Fernández Ridge (JFR), near 33 S, 73 W, off the coast of central Chile. The JFR is an aseismic hot spot ridge that has a thickened oceanic crust. The overthickened crust reduces the total density of the slab when compared to the surrounding slab areas, and thus increases the buoyancy of the subducting Nazca plate at this particular location. It is hypothesized that the Nazca plate experiences “flat-slab” subduction at the JFR subduction zone due to this buoyancy. Brudzinski and Chen (2005) argue that, due to the poorly aligned direction of maximum extension (T axes) for earthquakes in the subducting slab in flat-slab subduction zones, the theory of “slab pull” may not be valid for flat-slab subduction zones, and there must be other forces at work. However, Anderson et al. (2007) develop new, more precise slab contours from newly determined earthquake locations and use these contours to qualitatively compare the earthquake data to slab dip directions and thus expected slab-pull directions. They conclude that T axes are parallel to slab dip, and thus slab pull is the only force necessary for explaining the T axis direction. In this study, we quantitatively compare extension produced in analog "flat-slab" models in the laboratory to T axes from the Anderson et al. (2007) study, extending and further testing their idea. Several materials comprise the analog models. Light corn syrup represents the asthenosphere, while silicon putty represents the lithosphere. Recreating the dynamics of the buoyant JFR necessitates two different densities of silly putty: a denser one for the bulk of the slab, and a less dense one for the buoyant ridge. Shallow circular indentations (strain ellipses) on the slab facilitate recording of the strain in the subducting slab. Video and still pictures record each

  15. Infrastructure development and agricultural exposure to climate variability and change: lessons from the Limarí basin in Central Chile

    NASA Astrophysics Data System (ADS)

    Vicuna, S.; Alvarez, P.; Melo, O.; Dale, L. L.; Meza, F. J.

    2012-12-01

    The Limarí basin, located in Central Chile, is a world famous example of how the development of reservoirs and irrigation infrastructure can reduce climate vulnerabilities allowing the economic development of a basin. Before the infrastructure was developed low value crops such as cereals dominated land use acreage. Today high value crops such as vineyards, orchards and vegetables account for almost 50% of total land and cereals have almost disappear. Key to this evolution have been the reduction in water supply variability, access to international markets, increased irrigation efficiency, and the existence of water markets and other flexible and strong institutions that have helped moving the water from low to high value uses. These factors are related to each other sharing infrastructure development as a common root. The system of reservoirs in the Limarí basin was designed and has been operated since its construction with the premise that droughts in this basin do not last longer than 4 years. Until recently that had been the case and farmers have been able to withstand the impacts of droughts. When faced with water supply reductions farmers would select from a set of options to accommodate their needs including: water market participation, groundwater extraction and crop irrigation and crop acreage decisions. The use of these options has even allowed increasing total irrigated land mostly through the expansion of permanent water demand crops. In the past 9 years however, the basin has experienced a longer than usual drought, interrupting the reservoir refilling cycle that characterized climate variability in the region. This situation has led to dramatically low reservoir levels and continuous reductions in water supply. In addition, due to the already high levels of irrigation efficiency and large amount of acreage devoted to permanent water demand crops, the effectiveness of the portfolio of options available to farmers to accommodate to these stressing

  16. Water Input and Water Release from the Subducting Nazca Plate along Southern Central Chile (33°S-46°S)

    NASA Astrophysics Data System (ADS)

    Voelker, D.; Stipp, M.

    2015-12-01

    The fixation of water in the oceanic crust and upper mantle, the flux of stored water into subduction zones and the partial liberation of those fluids underneath the forearc and arc are mechanisms that impact on almost every aspect of subduction zone processes, e.g. intensity and type of arc volcanism, deposition of ores and seismicity of the subduction fault, but also on global geochemical budgets by recycling material back into the continental crust. Much of that water fixation happens at the outer rise of subduction zones in particular by deep percolation of fluids to the upper mantle along bend faults. Offshore Chile, the age of the subducting Nazca Plate varies between 0 Ma at the Chile Triple Junction (46°S) and ~38 Ma at the latitude of Valparaíso (32°S). Age-related variations in the thermal state of the subducting Nazca Plate impact on the water influx to the subduction zone, as well as the volumes of water that are released under the continental forearc or, alternatively, carried into the deeper mantle. Southern Central Chile is an ideal setting to study this effect, because other factors important for the subduction zone water budget appear constant. We determine the water influx by calculating the crustal water uptake and by modeling the upper mantle serpentinization at the outer rise of the Chile Trench. The water release under forearc and arc is determined by coupling FEM thermal models of the subducting plate with stability fields of water-releasing mineral reactions for upper and lower crust and hydrated mantle. Results show that both the influx and the release of water vary drastically over a length of 1500 km. In particular, the oldest and coldest segments carry roughly twice as much water into the subduction zone as the youngest and hottest segments, but their release flux to the forearc is only about one fourth of the latter. This high variability over a subduction zone of ~1500 km length shows that it is insufficient to consider subduction

  17. A quantitative high-resolution summer temperature reconstruction back to AD 850 based on sedimentary pigments from Laguna Aculeo, Central Chile

    NASA Astrophysics Data System (ADS)

    von Gunten, L.; Grosjean, M.; Rein, B.; Urrutia, R.; Appleby, P.

    2009-12-01

    A quantitative high-resolution (3-5 years) austral summer DJF (December to February) temperature reconstruction for the central region of Chile back to AD 850 is presented here. We used non-destructive multi-channel in situ reflection spectrometry data from a short sediment core from Laguna Aculeo, Central Chile (33°50'S/70°54'W, 355m a.s.l.). The age model is based on 137Cs and 14C dates, and a series of seismites related to major historical earthquakes. Calibration-in-time (period AD 1901-2000, cross-validated with split periods) revealed robust correlations between local DJF temperatures (CRU TS 2.1) and total sedimentary chlorin (a proxy for biological productivity measured using the relative absorption band depth (RABD) centred in 660-670 nm RABD660;670: r=0.79, P<0.01; five-years triangular filtered) and the degree of pigment diagenesis (R660nm/670nm: r=0.82, P<0.01; five-years triangular filtered). The DJF temperature reconstructions back to AD 850 were then calculated using scaling and linear regression techniques; Root Mean Squared Error values are small (between 0.24 and 0.34°C) suggesting that most of the reconstructed decadal-scale climate variability is significant. Our data provide quantitative evidence for the presence of a Medieval Climate Anomaly (in this case, warm summers between AD 1150 and 1350; ΔT = +0.27 to +0.37°C with respect to (wrt) twentieth century) and a cool period synchronous to the ‘Little Ice Age’ starting with a sharp drop between AD 1350 and AD 1400 (-0.3°C/10 yr, decadal trend) followed by constantly cool (ΔT = -0.70 to -0.90°C wrt twentieth century) summers until AD 1750. This lake sediment-based summer temperature record for central Chile is particularly valuable as most other known natural climate archives in this area (mostly tree rings) are sensitive to winter precipitation. Instrumental DJF temperatures and the reconstruction back to AD 850 (3-year resolution)

  18. Development and implementation of a monitoring and information system to increase water use efficiency in arid and semi-arid areas in Limarí, Central Chile (WEIN)

    NASA Astrophysics Data System (ADS)

    Berger, Erich; Balmert, David; Richter, Jürgen

    2016-10-01

    The project WEIN was funded by the Federal Ministry of Education and Research (BMBF | Berlin, Germany) in the framework of the high-tech strategy of Germany's program "KMU-Innovativ". The project started in 2012 and was completed in 2014. In the scope of the project, an integrated system for analysis, monitoring and information at river basin level was developed, which provides relevant information for all stakeholders that are concerned with water resource issues. The main objective of the project was to improve water use efficiency and hence ensure the agricultural production in the region. The pilot region, in which this system was implemented, is the semi-arid Limarí basin in Northern Central Chile. One of the main parts of the project was the development and implementation of a web- and app-based irrigation water ordering and accounting system for local farmers.

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

    NASA Astrophysics Data System (ADS)

    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.

  20. Wind forcing and short-term variability of phytoplankton and heterotrophic bacterioplankton in the coastal zone of the Concepción upwelling system (Central Chile)

    NASA Astrophysics Data System (ADS)

    Daneri, Giovanni; Lizárraga, Lorena; Montero, Paulina; González, Humberto E.; Tapia, Fabián J.

    2012-01-01

    Along South-Central Chile, upwelling-favorable winds do not blow steadily equatorward, and may remain calm or even reverse for periods of 2-8 days shifting the balance between water column stability and replenishment of inorganic nutrients to the photic zone. In this study, we focus on the short-term variability of phytoplankton and heterotrophic bacterioplankton associated with the temporal variability in upwelling at a single nearshore station at the entrance of Coliumo Bay, Central Chile. In situ sampling took place every other day between 24 January and 14 February 2007. Observed variability of wind, sea surface temperature, and surface chlorophyll concentrations during the preceding weeks and throughout our experiments indicated that nearshore productivity was tightly coupled to local upwelling conditions. Gross primary production remained relatively low (22.5 ± 6.1 μg C L -1 h -1) during the first 8 days (24 January-1 February), and increased six fold (142.4 ± 67.1 μg C L -1 h -1) during the second period (3-14 February). Average in situ chlorophyll concentrations increased from 2.0 ± 0.6 mg m -3 to 6.3 ± 3.8 mg m -3 over the same period. Bacterial Carbon Demand presented higher values (5-29.2 μg C L -1 h -1) during the first 6 days of sampling and lower values (<0.1 μg C L -1 h -1) for the rest of study period. Our results show that both biological productivity and the structure of the planktonic community can vary considerably due to short-term changes in wind conditions. Hence, previous productivity estimates for the Concepción upwelling ecosystem - based on observations gathered at lower frequencies - may not truly reflect its productivity potential.

  1. Impact of Santiago de Chile urban atmospheric pollution on anthropogenic trace elements enrichment in snow precipitation at Cerro Colorado, Central Andes

    NASA Astrophysics Data System (ADS)

    Cereceda-Balic, F.; Palomo-Marín, M. R.; Bernalte, E.; Vidal, V.; Christie, J.; Fadic, X.; Guevara, J. L.; Miro, C.; Pinilla Gil, E.

    2012-02-01

    Seasonal snow precipitation in the Andes mountain range is evaluated as an environmental indicator of the composition of atmospheric emissions in Santiago de Chile metropolitan area, by measuring a set of representative trace elements in snow samples by ICP-MS. Three late winter sampling campaigns (2003, 2008 and 2009) were conducted in three sampling areas around Cerro Colorado, a Central Andes mountain range sector NE of Santiago (36 km). Nevados de Chillán, a sector in The Andes located about 500 km south from the metropolitan area, was selected as a reference area. The experimental results at Cerro Colorado and Nevados de Chillán were compared with previously published data of fresh snow from remote and urban background sites. High snow concentrations of a range of anthropogenic marker elements were found at Cerro Colorado, probably derived from Santiago urban aerosol transport and deposition combined with the effect of mining and smelting activities in the area, whereas Nevados de Chillán levels roughly correspond to urban background areas. Enhanced concentrations in surface snow respect to deeper samples are discussed. Significant differences found between the 2003, 2008 and 2009 anthropogenic source markers profiles at Cerro Colorado sampling points were correlated with changes in emission sources at the city. The preliminary results obtained in this study, the first of this kind in the southern hemisphere, show promising use of snow precipitation in the Central Andes as a suitable matrix for receptor model studies aimed at identifying and quantifying pollution sources in Santiago de Chile.

  2. Long-term responses of sandy beach crustaceans to the effects of coastal armouring after the 2010 Maule earthquake in South Central Chile

    NASA Astrophysics Data System (ADS)

    Rodil, Iván F.; Jaramillo, Eduardo; Acuña, Emilio; Manzano, Mario; Velasquez, Carlos

    2016-02-01

    Earthquakes and tsunamis are large physical disturbances frequently striking the coast of Chile with dramatic effects on intertidal habitats. Armouring structures built as societal responses to beach erosion and shoreline retreat are also responsible of coastal squeeze and habitat loss. The ecological implications of interactions between coastal armouring and earthquakes have recently started to be studied for beach ecosystems. How long interactive impacts persist is still unclear because monitoring after disturbance generally extends for a few months. During five years after the Maule earthquake (South Central Chile, February 27th 2010) we monitored the variability in population abundances of the most common crustacean inhabitants of different beach zones (i.e. upper, medium, and lower intertidal) at two armoured (one concrete seawall and one rocky revetment) and one unarmoured sites along the sandy beach of Llico. Beach morphology changed after the earthquake-mediated uplift, restoring upper- and mid-shore armoured levels that were rapidly colonized by typical crustacean species. However, post-earthquake increasing human activities affected the colonization process of sandy beach crustaceans in front of the seawall. Lower-shore crab Emerita analoga was the less affected by armouring structures, and it was the only crustacean species present at the three sites before and after the earthquake. This study shows that field sampling carried out promptly after major disturbances, and monitoring of the affected sites long after the disturbance is gone are effective approaches to increase the knowledge on the interactive effects of large-scale natural phenomena and artificial defences on beach ecology.

  3. Air quality forecasting for winter-time PM2.5 episodes occurring in multiple cities in central and southern Chile

    NASA Astrophysics Data System (ADS)

    Saide, Pablo E.; Mena-Carrasco, Marcelo; Tolvett, Sebastian; Hernandez, Pablo; Carmichael, Gregory R.

    2016-01-01

    Episodic air quality degradation due to particles occurs in multiple cities in central and southern Chile during the austral winter reaching levels up to 300-800 µg/m3 hourly PM2.5, which can be associated with severe effects on human health. An air quality prediction system is developed to predict such events in near real time up to 3 days in advance for nine cities with regular air quality monitoring: Santiago, Rancagua, Curicó, Talca, Chillan, Los Ángeles, Temuco, Valdivia, and Osorno. The system uses the Weather Research and Forecasting with Chemistry model configured with a nested 2 km grid-spacing domain to predict weather and inert tracers. The tracers are converted to hourly PM2.5 concentrations using an observationally based calibration which is substantially less computationally intensive than a full chemistry model. The conversion takes into account processes occurring in these cities, including higher likelihood of episode occurrence during weekends and during colder days, the latter related to increased wood-burning-stove activity for heating. The system is calibrated and evaluated for April-August 2014 where it has an overall skill of 53-72% of episodes accurately forecasted (61-76% for the best initialization) which is better than persistence for most stations. Forecasts one, two, and three days in advance all have skill in forecasting events but often present large variability within them due to different meteorological initializations. The system is being implemented in Chile to assist authority decisions not only to warn the population but also to take contingency-based emission restrictions to try to avoid severe pollution events.

  4. Distribution of Pleuroncodes monodon larvae over the continental shelf of south-central Chile: Field and modeling evidence for partial local retention and transport

    NASA Astrophysics Data System (ADS)

    Yannicelli, Beatriz; Castro, Leonardo; Parada, Carolina; Schneider, Wolfgang; Colas, Francois; Donoso, David

    2012-01-01

    In situ and modeled spatial distribution of squat lobster ( Pleuroncodes monodon) larvae over the continental shelf off south central Chile (35-37°S) was analyzed along with currents and hydrography. We aimed to identify the main larval transport/retention characteristics in the study area, which constitutes the southernmost P. monodon fishing grounds embedded in the Humboldt Current System. We hypothesized that the main contribution to population renewal originates in the two persistent adult aggregations close to the nursery ground that occurs over a continental shelf terrace limited by two submarine canyons. Two extensive bio-physical field campaigns were carried out during the main 2001-2002 upwelling season field data indicated that larvae were released from late austral winter to spring from spots to the north and south of the nursery. Zoea I were found mainly below 50 m depth in southward-flowing waters, whereas older zoea dominated in northward flowing layers above 50 m. Larvae were circumscribed between the coast and the shelf break front and pelagic retention areas were identified over the widest shelf area. Megalopa and juveniles during March, were only found over the nursery area. Individual based simulations coupled to the output of a hydrodynamic model (climatological configuration) for the studied area, showed that the release sites close to the nursery made the largest contribution to recruitment. Sites further north could also contribute to recruitment if hatching occurred later in the upwelling season. The contribution of vertical behavior to larval success was also important, as was the former’s interaction with the site and time of larval release. Our results support the relevance of coastal circulation (affected by topography) on the persistence of P. monodon populations off southern Chile, and the modulation of temporal variability. These results might apply to other abundant species in the area.

  5. Impact of structural and autocyclic basin-floor topography on the depositional evolution of the deep-water Valparaiso forearc basin, central Chile

    USGS Publications Warehouse

    Laursen, J.; Normark, W.R.

    2003-01-01

    The Valparaiso Basin constitutes a unique and prominent deep-water forearc basin underlying a 40-km by 60-km mid-slope terrace at 2.5-km water depth on the central Chile margin. Seismic-reflection data, collected as part of the CONDOR investigation, image a 3-3.5-km thick sediment succession that fills a smoothly sagged, margin-parallel, elongated trough at the base of the upper slope. In response to underthrusting of the Juan Ferna??ndez Ridge on the Nazca plate, the basin fill is increasingly deformed in the seaward direction above seaward-vergent outer forearc compressional highs. Syn-depositional growth of a large, margin-parallel monoclinal high in conjunction with sagging of the inner trough of the basin created stratal geometries similar to those observed in forearc basins bordered by large accretionary prisms. Margin-parallel compressional ridges diverted turbidity currents along the basin axis and exerted a direct control on sediment depositional processes. As structural depressions became buried, transverse input from point sources on the adjacent upper slope formed complex fan systems with sediment waves characterising the overbank environment, common on many Pleistocene turbidite systems. Mass failure as a result of local topographic inversion formed a prominent mass-flow deposit, and ultimately resulted in canyon formation and hence a new focused point source feeding the basin. The Valparaiso Basin is presently filled to the spill point of the outer forearc highs, causing headward erosion of incipient canyons into the basin fill and allowing bypass of sediment to the Chile Trench. Age estimates that are constrained by subduction-related syn-depositional deformation of the upper 700-800m of the basin fill suggest that glacio-eustatic sea-level lowstands, in conjunction with accelerated denudation rates, within the past 350 ka may have contributed to the increase in simultaneously active point sources along the upper slope as well as an increased

  6. Fungal parasites infect marine diatoms in the upwelling ecosystem of the Humboldt current system off central Chile.

    PubMed

    Gutiérrez, Marcelo H; Jara, Ana M; Pantoja, Silvio

    2016-05-01

    This is the first report of fungal parasitism of diatoms in a highly productive coastal upwelling ecosystem, based on a year-round time series of diatom and parasitic Chytridiomycota abundance in the Humboldt Current System off Chile (36°30.80'S-73°07.70'W). Our results show co-variation in the presence of Skeletonema, Thalassiosira and Chaetoceros diatoms with attached and detached chytrid sporangia. High abundance of attached sporangia was observed during the austral spring, coinciding with a predominance of Thalassiosira and Skeletonema under active upwelling conditions. Towards the end of austral spring, a decreasing proportion of attached sporangia was accompanied by a decline in abundance of Skeletonema and Thalassiosira and the predominance of Chaetoceros, suggesting specificity and host density dependence of chytrid infection. The new findings on fungal parasitism of diatoms provide further support for the inclusion of Fungi in the current model of the role played by the marine microbial community in the coastal ocean. We propose a conceptual model where Fungi contribute to controlling the dynamics of phytoplankton populations, as well as the release of organic matter and the transfer of organic carbon through the pelagic trophic web in coastal upwelling ecosystems. PMID:26914416

  7. Evaluation of azinphos-methyl resistance and activity of detoxifying enzymes in codling moth (Lepidoptera: Tortricidae) from central Chile.

    PubMed

    Fuentes-Contreras, Eduardo; Reyes, Maritza; Barros, Wilson; Sauphanor, Benoît

    2007-04-01

    Regular applications of insecticides have been the main management practice against codling moth, Cydia pomonella (L.) (Lepidoptera: Tortricidae) in Chile. Organophosphates are the most widely used insecticides, and azinphos-methyl is an important element in spray programs. In particular, we evaluated diagnostic doses of azinphos-methyl on neonate and postdiapausing larvae from seven apple (Malus spp.) orchards. We also evaluated the activity of detoxifying enzymes, such as glutathione S-transferases (GSTs), cytochrome P450 polysubstrate monooxygenases (PSMOs), and esterases, which are likely to be involved in resistance to insecticides. Such responses were compared with an insecticide-susceptible strain that has been maintained in the laboratory for several years. Neonate larval mortality of field populations to azinphos-methyl was not significantly different from of the susceptible strain. In contrast, postdiapause larval mortality was significantly lower in the six analyzed populations than in the susceptible strain. The C. pomonella populations with reduced postdiapause mortality to azinphos-methyl also showed statistically higher GST activity. Finally, no significant differences were found in total esterase or PSMO activity between C. pomonella populations. Therefore, the observed reduction in postdiapause larval mortality to azinphos-methyl seems to be associated with an increase in GST activity. PMID:17461082

  8. Assessing the "two water worlds hypothesis", and water sources for native and exotic evergreen species in south-central Chile

    NASA Astrophysics Data System (ADS)

    Hervé Fernández, Pedro; Oyarzún, Carlos; Huyghens, Dries; Verhoest, Niko; Boeckx, Pascal

    2016-04-01

    Recent studies using water stable isotopes (δ2H and δ18O) have described an ecohydrological separation of water between streams and trees indicated as the "two water world hypothesis". In this study, we monitored water compartments at two catchments near Valdivia (Chile) covered by old growth native evergreen forest (NF) and a Eucalyptus nitens stand covered catchment (or EP), throughout approximately 1.5 years. Our results showed that precipitation, stream and suction lysimeter water plots approximately along the δ2H/δ18O slope of local precipitation inputs (LMWL). However, bulk soil and xylem water plots below the LMWL, supporting the "two water worlds hypothesis". This suggests that trees are using water that is not contributing to stream water. However, we also found evidence of connectivity between the two water worlds, potentially caused by heavy rainfall events, for a brief period (autumn and winter) especially in EP. Our results also suggests that precipitation falling during autumn-winter period is the main water supply for streamflow and bulk soil water, which share a similar precipitation source as Aetoxicon punctatum (in NF) and 4 years old Eucalyptus nitens stand (in EP). We conclude that the "two water worlds hypothesis" applies under certain environmental conditions.

  9. Delineation of the High Enthalpy Reservoirs of the Sierra Nevada Volcanic Geothermal System, South-Central Chile

    NASA Astrophysics Data System (ADS)

    Alam, M.; Muñoz, M.; Parada, M.

    2011-12-01

    Geothermal system associated with the Pleistocene-Holocene Sierra Nevada volcano (SNVGS) in the Araucanía Region of Chile has surface manifestations from the north-western flank of the volcano, up to Manzanar and Malalcahuello. Baños del Toro, located on the northwestern flank of the volcano, has numerous fumaroles and acid pools (acid sulfate waters, T=~90°C, pH=2.1, TDS=3080 mg/L); while Aguas de la Vaca, near the base of the volcano, has a bubbling spring (chloride-sulfate waters, T=~60°C, pH=7.0, TDS=950 mg/L). Five shallow (<120m) wells (2 at Manzanar and 3 at Malalcahuello) dug and drilled in the Cautín River Valley discharge alkaline (pH= 9-10) waters with relatively low TDS (130-210mg/L). The main heat source of the geothermal system is apparently the magmatic system of the Sierra Nevada volcano. Liquiñe-Ofqui Fault Zone (LOFZ) that transects the area forms excellent conduits for the flow of the geothermal waters. The geothermal reservoirs are hosted in the volcanic rocks interceded with glacial deposits over the North Patagonian Batholith that forms an impermeable barrier, and thus constitutes the lower boundary of the geothermal system and also controls the lateral flow of the fluids. An equilibrium temperature of ~210°C is derived from gas geothermometry (CO2/Ar-H2/Ar) of the discharges at Baños del Toro. Geothermal fluids from the upflow area on the northwestern flank of the volcano migrate northwards to the Cautín River Valley. The geothermal system has a high enthalpy reservoir(s) on the northwestern flank of the Sierra Nevada volcano and low-enthalpy reservoirs in the Cautín River Valley that have been tapped to form spas at Manzanar and Malalcahuello. While sub-vertical fractures of LOFZ facilitate the recharge of the system, lateral flow of the geothermal fluids is apparently controlled by lithology; Melipueclo Pluton in particular prevents the westward flow from the upflow zone, causing the flow only northwards to Malalcahuello and

  10. A New, Continuous 5400 Yr-long Paleotsunami Record from Lake Huelde, Chiloe Island, South Central Chile.

    NASA Astrophysics Data System (ADS)

    Kempf, P.; Moernaut, J.; Vandoorne, W.; Van Daele, M. E.; Pino, M.; Urrutia, R.; De Batist, M. A. O.

    2014-12-01

    After the last decade of extreme tsunami events with catastrophic damage to infrastructure and a horrendous amount of casualties, it is clear that more and better paleotsunami records are needed to improve our understanding of the recurrence intervals and intensities of large-scale tsunamis. Coastal lakes (e.g. Bradley Lake, Cascadia; Kelsey et al., 2005) have the potential to contain long and continuous sedimentary records, which is an important asset in view of the centennial- to millennial-scale recurrence times of great tsunami-triggering earthquakes. Lake Huelde on Chiloé Island (42.5°S), Chile, is a coastal lake located in the middle of the Valdivia segment, which is known for having produced the strongest ever instrumentally recorded earthquake in 1960 AD (MW: 9.5), and other large earthquakes prior to that: i.e. 1837 AD, 1737 AD (no report of a tsunami) and 1575 AD (Lomnitz, 1970, 2004, Cisternas et al., 2005). We present a new 5400 yr-long paleotsunami record with a Bayesian age-depth model based on 23 radiocarbon dates that exceeds all previous paleotsunami records from the Valdivia segment, both in terms of length and of continuity. 18 events are described and a semi-quantitative measure of the event intensity at the study area is given, revealing at least two predecessors of the 1960 AD event in the mid to late Holocene that are equal in intensity. The resulting implications from the age-depth model and from the semi-quantitative intensity reconstruction are discussed in this contribution.

  11. Distribution and Diversity of Pathogenic Leptospira Species in Peri-domestic Surface Waters from South Central Chile

    PubMed Central

    Mason, Meghan R.; Encina, Carolina; Sreevatsan, Srinand; Muñoz-Zanzi, Claudia

    2016-01-01

    Background Leptospirosis is a neglected zoonosis affecting animals and humans caused by infection with Leptospira. The bacteria can survive outside of hosts for long periods of time in soil and water. While identification of Leptospira species from human cases and animal reservoirs are increasingly reported, little is known about the diversity of pathogenic Leptospira species in the environment and how surveillance of the environment might be used for monitoring and controlling disease. Methods and Findings Water samples (n = 104) were collected from the peri-domestic environment of 422 households from farms, rural villages, and urban slums participating in a broader study on the eco-epidemiology of leptospirosis in the Los Rios Region, Chile, between October 2010 and April 2012. The secY region of samples, previously detected as pathogenic Leptospira by PCR, was amplified and sequenced. Sequences were aligned using ClustalW in MEGA, and a minimum spanning tree was created in PHYLOViZ using the goeBURST algorithm to assess sequence similarity. Sequences from four clinical isolates, 17 rodents, and 20 reference strains were also included in the analysis. Overall, water samples contained L. interrogans, L. kirschneri, and L. weilii, with descending frequency. All species were found in each community type. The distribution of the species differed by the season in which the water samples were obtained. There was no evidence that community-level prevalence of Leptospira in dogs, rodents, or livestock influenced pathogen diversity in the water samples. Conclusions This study reports the presence of pathogenic Leptospira in the peri-domestic environment of households in three community types and the differences in Leptospira diversity at the community level. Systematic environmental surveillance of Leptospira can be used for detecting changes in pathogen diversity and to identify and monitor contaminated areas where an increased risk of human infection exists. PMID

  12. Late Miocene high and rapid surface uplift and its erosional response in the Andes of central Chile (33°-35°S)

    NASA Astrophysics Data System (ADS)

    FaríAs, Marcelo; Charrier, Reynaldo; Carretier, SéBastien; Martinod, Joseph; Fock, AndréS.; Campbell, David; CáCeres, JoaquíN.; Comte, Diana

    2008-02-01

    We address the question of the late Cenozoic geomorphological evolution of the central Chile Andes (33°-35°S), using uplift markers, river incision, previous and new ages of volcanic bodies, and new fission track ages. The uplift markers consist of relicts of high elevated peneplains that evidence >2 km of regional surface uplift lasting ˜2 Ma with variable amount along an E-W transect. The eastern Coastal Cordillera was uplifted 1.5-2.1 km at 33-34°S and <1 km at 35°S, the western Principal Cordillera was uplifted ˜2 km, and the central eastern Principal Cordillera was uplifted >2.5 at 33°45'S and ˜1.5 km at 34°30'S. Erosional response to uplift was characterized by the retreat of a sharp knickpoint with celerities between 10 and 40 mm a-1. Extrapolation using a stream power law shows that uplift began shortly before 4 Ma or at 10.5-4.6 Ma (7.6 Ma central age) depending on the morphostructural units involved. The first alternative implies simultaneous uplift of the continental margin. The second model (the most reliable one) implies that the uplift affected together the eastern Coastal Cordillera and the Principal Cordillera, while the rest of the western fore arc subsided. This regional uplift can be mostly balanced by crustal thickening resulting from coeval shortening related to the out-of-sequence thrusting event in the Principal Cordillera and the uplift of the Frontal Cordillera. Simultaneously, emplacement of the southern edge of the flat slab subduction zone might have partially contributed to this uplift event.

  13. Use of Daphnia spp. for the ecotoxicological assessment of water quality in an agricultural watershed in South-Central Chile.

    PubMed

    Cooman, K; Debels, P; Gajardo, M; Urrutia, R; Barra, R

    2005-02-01

    Because of the importance of surface waters from the Chillán River watershed (Chile) for recreation, agricultural irrigation, and the production of drinking water, local concern about river water quality has increased considerably during the last decade. Agricultural and forestry activities in the watershed, characterized by an intensive use of pesticides, are thought to play an important role in the generation of non-point-source pollution, whereas the discharge of urban wastewater from the city of Chillán constitutes a major point source of pollution. In the present investigation, acute and chronic laboratory bioassays using Daphnia spp. were conducted on surface water samples from 17 river stations located throughout the watershed. Sampling occurred on 6 occasions during a 16-month period (2000 to 2001) and included both high and low flow conditions. Almost all toxic effects observed in summer were directly related to the discharge of urban wastewater, whereas toxicity in rural areas was mainly detected during the winter period when rainfall and river flow are high. Toxicity test results were compared with measured physicochemical water-quality data. Mortality and alterations in reproductive success of Daphnia spp. were not consistently reflected in detected chemical pollution. With only one exception (atrazine), detected pesticide concentrations were below known toxicity levels. However, additive and synergistic effects of the presence of a mixture of pesticides could not be excluded as a possible cause of observed toxicity. At several stations, filtering of the water sample led to a strong decrease in toxicity, which suggests the presence of xenobiotics attached to the smaller sediment fraction. Inclusion of sediment chemical analysis and sediment toxicity testing in future work should therefore be encouraged. The presented approach provided information about the adverse effects of human activities on surface water quality in the watershed, not easily

  14. Nitrospina-like bacteria are the main drivers of nitrite oxidation in the seasonal upwelling area of the Eastern South Pacific (Central Chile ∼36°S).

    PubMed

    Levipan, Héctor A; Molina, Verónica; Fernandez, Camila

    2014-12-01

    Aerobic nitrite oxidation in marine environments plays a key role in the nitrification process. Marine bacteria involved in this nitrate-producing process have however been seldom studied compared with the ammonia-oxidizing community. Here, we report for the first time the community structure of aerobic nitrite-oxidizing bacteria (NOB) in the seasonal upwelling and oxygen-deficient area off Central Chile. Analysis of 16S rRNA by tag pyrosequencing was combined with specific quantitative polymerase chain reaction (qPCR) and reverse transcription qPCR in summer and wintertime. Nitrospina-like bacteria were the only known NOB detected by means of pyrosequencing between 30 and 80 m depth, accounting for up to 5% of total bacteria. This guild was represented by 11 and 7 operational taxonomic units (97% cut-off) in winter and summertime respectively. Nitrospina-like bacteria were phylogenetically related to sequences retrieved from coastal upwelling, oxygen minimum zones and deep-sea environments. This group was also detected by qPCR with abundances that increased with depth throughout the water column. Importantly, Nitrospina from surface layers showed low abundances but high 16S rRNA : rDNA ratios and mainly in summertime. Overall, our results highlight the seasonal variability between the structure and physiological state of this community and suggest a significant role of Nitrospina in the nitrogen cycle of seasonal upwelling areas. PMID:25756109

  15. Increased parasitism of limpets by a trematode metacercaria in fisheries management areas of central Chile: effects on host growth and reproduction : management areas and parasitism.

    PubMed

    Aldana, Marcela; Pulgar, José M; Orellana, Nathalie; Patricio Ojeda, F; García-Huidobro, M Roberto

    2014-06-01

    The rapid increase in body size and abundance of most species inside Management and Exploitations Areas for Benthic Resources (MEABRs) has led to the proposal of these areas as a good complement for achieving the conservation objectives of Marine Protected Areas (MPAs). However, when evaluating MEABRs and MPAs as conservation and/or management tools, their impact upon parasite populations has rarely been considered, despite the fact that epidemiological theory suggests an increased susceptibility to parasitism under high population abundance. We evaluated the effects of MEABRs on the parasite abundance of Proctoeces lintoni and its impact on the growth of the host limpet Fissurella crassa in central Chile. Parasitic magnitude was higher inside MEABRs than in Open-Access Areas, and parasitized limpets showed a greater shell length, muscular foot biomass, and gonadosomatic index compared to non-parasitized limpets of the same age. Our results suggest that the life cycle of P. lintoni and, consequently, its trophic links have been strengthened inside MEABRs. The increased growth rate could reduce the time required to reach the minimum catch size and increase the reproductive and muscular output of the host population. Thus, parasitism should be considered in the conservation and management of economically important mollusk hosts. PMID:24142461

  16. Tectonic inversion and magmatism in the Lautaro Basin, northern Chile, Central Andes: A comparative approach from field data and analog models

    NASA Astrophysics Data System (ADS)

    Martínez, Fernando; Bonini, Marco; Montanari, Domenico; Corti, Giacomo

    2016-03-01

    We present the results of a series of analog models addressing the relationships between tectonic inversion and magmatism, taking the Lautaro Basin in northern Chile (27-28° S), Central Andes as a natural case. The experiments consisted of extension and orthogonal shortening of sand-silicone models to reproduce the tectonic inversion of a previous extensional system synchronous with the emplacement of analog magma. We analyzed how the variation in the rate of magma intrusion, shortening, and syn-compressive sedimentation may affect the final configuration of an inverted system, and the results were compared with field observations. Our results showed that (i) folding of syn-rift deposits and increased steepness of the master faults accommodate the shortening of the extensional system, (ii) magmatic intrusions condition the final geometries (top view and cross-section) of inverted normal faults in the models and in the Lautaro Basin, (iii) magma tends to migrate preferentially along the inverted faults, and accumulates beneath the faults and in the core of the inversion anticlines, (iv) the syn-inversion magmatism may indicate the migration pathways, which favor major lubrication and slip on the structures during their reactivation.

  17. PAH fluxes in the Laja Lake of south central Chile Andes over the last 50 years: evidence from a dated sediment core.

    PubMed

    Quiroz, Roberto; Popp, Peter; Urrutia, Roberto; Bauer, Coretta; Araneda, Alberto; Treutler, Hanns-Christian; Barra, Ricardo

    2005-10-15

    This paper reports the occurrence of polyaromatic hydrocarbons (PAHs) deposition inferred from a sediment core of an Andean lake in south central Chile. Sediments were carefully collected from one of the deepest section of the lake and sliced every 1 cm. The samples were analyzed for PAHs, (137)Cs, (210)Pb, organic carbon and grain-size. The stratigraphic chronology and the sedimentation rates were estimated using the sedimentary signature left by the (137)Cs and (210)Pb fallout as temporal markers. PAHs were quantified by HPLC-fluorescence detection (HPLC-Fluorescence). 15 priority EPA PAHs were analyzed in this study. Based on these results, PAH deposition over the last 50 years was estimated (a period characterized by an important intervention in the area). PAH concentration ranged from 226 to 620 ng g(-1) d.w. The highest concentrations of PAHs were found in the core's bottom. The PAH profile is dominated by the presence of perylene indicating a natural source of PAH. In addition, two clear PAH deposition periods could be determined: the most recent with two-four rings PAHs, the older one with five-seven rings predomination. Determined fluxes where 71 to 972 microg m(-2) year(-1), dominated by perylene deposition. PAH levels and fluxes are lower compared to the levels found in sediments from remote lakes in Europe and North America. It is concluded that the main source of PAHs into the Laja Lake sediments are of natural origin.

  18. Twelve Years of Change in Coastal Upwelling along the Central-Northern Coast of Chile: Spatially Heterogeneous Responses to Climatic Variability

    PubMed Central

    Aravena, Guillermo; Broitman, Bernardo; Stenseth, Nils Christian

    2014-01-01

    We use time-series analyses to characterize the effects of recent climate variability upon the local physical conditions at 11 study sites along the northern-central coast of Chile (29–34°S). Environmental indices show that the 1° Bakun upwelling index in this coastal region has fluctuated in time, starting from a stable period around the 1980's, peaking during the mid 90s, decreasing during the next ten years and increasing at a steep rate since 2010. Upwelling intensity decreased with increasing latitude, showing also a negative correlation with climate patterns (El Niño3 sea surface temperature-SST anomalies and the Multivariate El Niño Index). We hypothesize that the impacts of climate variability on upwelling events seem to be spatially heterogeneous along the region. Non-sheltered locations and, particularly, sites on prominent headlands show an immediate (lag = 0) and negative correlation between local SST, upwelling events and wind stress. We suggest that near-shore thermal conditions are closely coupled to large-scale forcing of upwelling variability and that this influence is modulated through local topographic factors. PMID:24587310

  19. Increased parasitism of limpets by a trematode metacercaria in fisheries management areas of central Chile: effects on host growth and reproduction : management areas and parasitism.

    PubMed

    Aldana, Marcela; Pulgar, José M; Orellana, Nathalie; Patricio Ojeda, F; García-Huidobro, M Roberto

    2014-06-01

    The rapid increase in body size and abundance of most species inside Management and Exploitations Areas for Benthic Resources (MEABRs) has led to the proposal of these areas as a good complement for achieving the conservation objectives of Marine Protected Areas (MPAs). However, when evaluating MEABRs and MPAs as conservation and/or management tools, their impact upon parasite populations has rarely been considered, despite the fact that epidemiological theory suggests an increased susceptibility to parasitism under high population abundance. We evaluated the effects of MEABRs on the parasite abundance of Proctoeces lintoni and its impact on the growth of the host limpet Fissurella crassa in central Chile. Parasitic magnitude was higher inside MEABRs than in Open-Access Areas, and parasitized limpets showed a greater shell length, muscular foot biomass, and gonadosomatic index compared to non-parasitized limpets of the same age. Our results suggest that the life cycle of P. lintoni and, consequently, its trophic links have been strengthened inside MEABRs. The increased growth rate could reduce the time required to reach the minimum catch size and increase the reproductive and muscular output of the host population. Thus, parasitism should be considered in the conservation and management of economically important mollusk hosts.

  20. The influence of upwelling variation on the spatially-structured euphausiid community off central-southern Chile in 2007-2008

    NASA Astrophysics Data System (ADS)

    Riquelme-Bugueño, Ramiro; Núñez, Sergio; Jorquera, Erika; Valenzuela, Lesly; Escribano, Rubén; Hormazábal, Samuel

    2012-01-01

    This study assesses the spatial and temporal patterns of the euphausiid community from the coastal upwelling zone and oceanic areas of central-southern Chile, surveyed between August 2007 and November 2008. A total of 22 species were found, most of them already described for the region. The numerically dominant species was Euphausia mucronata for the entire study area (>60%), which was found in more oceanic waters (>90°W), thereby expanding its longitudinal distribution range. The species showed distinct spatial distribution patterns, allowing its classification as a coastal, oceanic, southern and northern species. The community descriptors - species richness, total abundance, Pielou and Shannon index - all had patterns associated with the cross-shelf and alongshore axes. Over a temporal scale, species abundance and community descriptors showed strong seasonal patterns. Abundances decreased offshore but diversity increased towards the oceanic area, revealing an inverse relationship between total abundance and the Shannon index. Diversity was positively related to sea surface temperature. Although the most abundant species were concentrated within the coastal zone, euphausiid abundance and diversity in the oceanic region were high. Our findings suggest that the high productivity of the upwelling region may sustain the euphausiid populations in the coastal transition zone and in the offshore region, and that high abundance and diversity across the entire region may be maintained by a highly heterogeneous environment promoted by upwelling, giving rise to an increased number of potential ecological niches.

  1. Seasonal mercury concentrations and δ15N and δ13C values of benthic macroinvertebrates and sediments from a historically polluted estuary in south central Chile.

    PubMed

    Díaz-Jaramillo, Mauricio; Muñoz, Claudia; Rudolph, Ignacio; Servos, Mark; Barra, Ricardo

    2013-01-01

    The Lenga Estuary is one of the most industrialized sites in south central Chile where the historic operation of chlor-alkali plants resulted in large quantities of mercury (Hg) being deposited into the estuary. This historical contamination may still represent a risk to the biota in the estuary. To investigate this four macroinvertebrates, Neotrypaea uncinata (ghostshrimp), Elminius kingii (barnacle), Hemigrapsus crenulatus (shore crab) and Perinereis gualpensis (ragworm) were collected seasonally from three different sites in the Lenga Estuary and one in a reference estuary (Tubul Estuary), and analyzed for Hg and stable isotopes (δ(15)N and δ(13)C). Mercury concentrations in Lenga sediments ranged from 0.4 ± 0.1 to 13 ± 3 mg/kg, while those in Tubul sediments ranged from 0.02 ± 0.01 to 0.07 ± 0.09 mg/kg. Total Hg concentrations of invertebrates were significantly different between estuaries (p<0.05), but not by species or season for each estuary (p>0.05). In contrast, organic Hg concentrations were different by species and season with shore crab muscle tissues exhibiting the greatest percent difference. Site-specific relationships demonstrated that total Hg concentrations in ragworm best reflected the total Hg sediment mercury concentrations. Signatures of δ(13)C were correlated to the organic Hg % rather than total Hg. This suggests that organic Hg concentrations in these species were related to the carbon sources.

  2. 1960 Valdivia earthquake tsunami deposits from two coastal lakes and preliminary results for an extended paleotsunami record of South-Central Chile

    NASA Astrophysics Data System (ADS)

    Kempf, Philipp; Moernaut, Jasper; Vandoorne, Willem; Van Daele, Maarten; Strasser, Michael; Pino, Mario; Urrutia, Roberto; De Batist, Marc

    2013-04-01

    After the large number of victims and the vast damage to infrastructure by tsunamis in the last decade the probabilistic risk evaluation and precautions need to be reconsidered. This reconsideration has to include more detailed studies on recent tsunamis and tsunamis from the historic and pre-historic record to avoid redundancy. Deposits of the 1960 Valdivia Earthquake tsunami and four of its local predecessors were previously identified in the sedimentary record at the estuary of Rio Maullín, (41°S) South-Central Chile (Cisternas et al., 2005). Here, we present side-scan sonar data, pinger seismic data and a multi-proxy analysis of sediment cores of up to 9 m length from two coastal lakes on La Isla Grande de Chiloé (42°S): i.e. Lago Cucao and Lago Huelde. These lakes have 1.2 km and 1.1 km wide and 10 m and 5 m high barriers between the Pacific coast and their shoreline, respectively. Data coverage is ensured by core transects, which correlate to the acoustic datasets. The good spatial control on the data allows a detailed understanding of the distribution of the tsunami deposits in the lakes. The 1960 tsunami hit the West coast of Chiloé with two to four large waves of 10 to 20 m run-up height, inundating both lakes. Multi-layered sand sheet deposits mirror the repeated inundation of wave trains in the otherwise organic-rich lake sediment record. We describe the link between the tsunami wave and its deposit and show two preliminary paleotsunami records comprising 15 events dating back to 3930 ± 90 cal yr BP, thus potentially extending the current paleotsunami record of the Valdivia seismic segment further back in time by at least 2000 years. References Cisternas, M., Atwater, B.F., Torrejon, F., Sawai, Y., Machuca, G., Lagos, M., Eipert, A., Youlton, C., Salgado, I., Kamataki, T., Shishikura, M., Rajendran, C.P., Malik, J.K., Rizal, Y., Husni, M., 2005. Predecessors of the giant 1960 Chile earthquake. Nature 437, 404-407.

  3. Effects of massive wind power integration on short-term water resource management in central Chile - a grid-wide study

    NASA Astrophysics Data System (ADS)

    Haas, J.; Olivares, M. A.; Palma, R.

    2013-12-01

    In central Chile, water from reservoirs and streams is mainly used for irrigation and power generation. Hydropower reservoirs operation is particularly challenging because: i) decisions at each plant impact the entire power system, and ii) the existence of large storage capacity implies inter-temporal ties. An Independent System Operator (ISO) decides the grid-wide optimal allocation of water for power generation, under irrigation-related constraints. To account for the long-term opportunity cost of water, a future cost function is determined and used in the short term planning. As population growth and green policies demand increasing levels of renewable energy in power systems, deployment of wind farms and solar plants is rising quickly. However, their power output is highly fluctuating on short time scales, affecting the operation of power plants, particularly those fast responding units as hydropower reservoirs. This study addresses these indirect consequences of massive introduction of green energy sources on reservoir operations. Short-term reservoir operation, under different wind penetration scenarios, is simulated using a replica of Chile's ISO's scheduling optimization tools. Furthermore, an ongoing study is exploring the potential to augment the capacity the existing hydro-power plants to better cope with the balancing needs due to a higher wind power share in the system. As reservoir releases determine to a great extent flows at downstream locations, hourly time series of turbined flows for 24-hour periods were computed for selected combinations between new wind farms and increased capacity of existing hydropower plants. These time series are compiled into subdaily hydrologic alteration (SDHA) indexes (Zimmerman et al, 2010). The resulting sample of indexes is then analyzed using duration curves. Results show a clear increase in the SDHA for every reservoir of the system as more fluctuating renewables are integrated into the system. High

  4. Aftershock seismicity and tectonic setting of the 16 September 2015 Mw 8.3 Illapel earthquake, Central Chile

    NASA Astrophysics Data System (ADS)

    Lange, Dietrich; Geersen, Jacob; Barrientos, Sergio; Moreno, Marcos; Grevemeyer, Ingo; Contreras-Reyes, Eduardo; Kopp, Heidrun

    2016-06-01

    Powerful subduction zone earthquakes rupture thousands of square kilometers along continental margins but at certain locations earthquake rupture terminates. To date detailed knowledge of the parameters that govern seismic rupture and aftershocks is still incomplete. On 16 September 2015 the Mw. 8.3 Illapel earthquake ruptured a 200 km long stretch of the Central Chilean subduction zone, triggering a tsunami and causing significant damage. Here we analyze the temporal and spatial pattern of the co-seismic rupture and aftershocks in relation to the tectonic setting in the earthquake area. Aftershocks cluster around the area of maximum coseismic slip, in particular in lateral and downdip direction. During the first 24 hours after the mainshock, aftershocks migrated in both lateral directions with velocities of approximately 2.5 and 5 km/h. At the southern rupture boundary aftershocks cluster around individual subducted seamounts that are related to the downthrusting Juan Fernández Ridge. In the northern part of the rupture area aftershocks separate into an upper cluster (above 25 km depth) and a lower cluster (below 35 km depth). This dual seismic-aseismic transition in downdip direction is also observed in the interseismic period suggesting that it may represent a persistent feature for the Central Chilean subduction zone.

  5. Aftershock seismicity and tectonic setting of the 2015 September 16 Mw 8.3 Illapel earthquake, Central Chile

    NASA Astrophysics Data System (ADS)

    Lange, Dietrich; Geersen, Jacob; Barrientos, Sergio; Moreno, Marcos; Grevemeyer, Ingo; Contreras-Reyes, Eduardo; Kopp, Heidrun

    2016-08-01

    Powerful subduction zone earthquakes rupture thousands of square kilometres along continental margins but at certain locations earthquake rupture terminates. To date, detailed knowledge of the parameters that govern seismic rupture and aftershocks is still incomplete. On 2015 September 16, the Mw 8.3 Illapel earthquake ruptured a 200 km long stretch of the Central Chilean subduction zone, triggering a tsunami and causing significant damage. Here, we analyse the temporal and spatial pattern of the coseismic rupture and aftershocks in relation to the tectonic setting in the earthquake area. Aftershocks cluster around the area of maximum coseismic slip, in particular in lateral and downdip direction. During the first 24 hr after the main shock, aftershocks migrated in both lateral directions with velocities of approximately 2.5 and 5 km hr-1. At the southern rupture boundary, aftershocks cluster around individual subducted seamounts that are related to the downthrusting Juan Fernández Ridge. In the northern part of the rupture area, aftershocks separate into an upper cluster (above 25 km depth) and a lower cluster (below 35 km depth). This dual seismic-aseismic transition in downdip direction is also observed in the interseismic period suggesting that it may represent a persistent feature for the Central Chilean subduction zone.

  6. Neogene to Quaternary ash deposits in the Coastal Cordillera in northern Chile: Distal ashes from supereruptions in the Central Andes

    NASA Astrophysics Data System (ADS)

    Breitkreuz, Christoph; de Silva, Shanaka L.; Wilke, Hans G.; Pfänder, Jörg A.; Renno, Axel D.

    2014-01-01

    Silicic volcanic ash deposits investigated at 14 localities between 22° and 25°S in the Chilean Coastal Cordillera are found to be the distal ash fall from supereruptions in the Central Andean cordillera several hundreds of kilometers to the east. Depositional textures, modal composition and granulometry of the ashes and tuffs (the latter lithified by halite and gypsum under ultra-arid conditions) allow for a distinction between primary fallout/aeolian deposits (mean 4-5 Φ, sorting 1.5-2 Φ) and secondary deposits that formed by down wash from hill slopes during local rain fall. Primary volcanic components comprise two types of glass shards (with small stretched vesicles and coarse-walled with rounded to elliptic vesicles), and biotite.

  7. Recruitment Dynamics of the Relict Palm, Jubaea chilensis: Intricate and Pervasive Effects of Invasive Herbivores and Nurse Shrubs in Central Chile

    PubMed Central

    Fleury, Marina; Marcelo, Wara; Vásquez, Rodrigo A.; González, Luis Alberto; Bustamante, Ramiro O.

    2015-01-01

    Shrubs can have a net positive effect on the recruitment of other species, especially relict species in dry-stressful conditions. We tested the effects of nurse shrubs and herbivory defoliation on performance (survival and growth) of nursery-grown seedlings of the largest living palm, the relict wine palm Jubaea chilensis. During an 18-month period, a total of more than 300 seedlings were exposed to of four possible scenarios produced by independently weakening the effects of nurse shrubs and browsers. The experiment followed a two-way fully factorial design. We found consistent differences in survival between protected and unprotected seedlings (27.5% and 0.7%, respectively), and herbivory had a dramatic and overwhelmingly negative effect on seedling survival. The invasive rabbit (Oryctolagus cuniculus) is clearly creating a critical bottleneck in the regeneration process and might, therefore, partially explain the general lack of natural regeneration of wine palms under natural conditions. Apparently biotic filters mediated by ecological interactions are more relevant in the early stages of recruitment than abiotic, at least in invaded sites of central Chile. Our data reveal that plant-plant facilitation relationship may be modulated by plant-animal interactions, specifically by herbivory, a common and widespread ecological interaction in arid and semi-arid environments whose role has been frequently neglected. Treatments that protect young wine palm seedlings are mandatory to enable the seedlings to attain a height at which shoots are no longer vulnerable to browsing. Such protection is an essential first step toward the conservation and reintroduction of this emblematic and threatened species. PMID:26218100

  8. Satellite-measured interannual variability of turbid river plumes off central-southern Chile: Spatial patterns and the influence of climate variability

    NASA Astrophysics Data System (ADS)

    Saldías, Gonzalo S.; Largier, John L.; Mendes, Renato; Pérez-Santos, Iván; Vargas, Cristian A.; Sobarzo, Marcus

    2016-08-01

    Ocean color imagery from MODIS (Moderate Resolution Imaging Spectroradiometer) onboard the Aqua platform is used to characterize the interannual variability of turbid river plumes off central-southern Chile. Emphasis is placed on the influence of climate fluctuations, namely El Niño Southern Oscillation (ENSO), the Pacific Decadal Oscillation (PDO), and the Antarctic Oscillation (AAO). Additional satellite data on wind, boat-based hydrographic profiles, and regional climate indices are used to identify the influence of climate variability on the generation of anomalous turbid river plumes. The evolution of salinity at a coastal station on the 90 m isobath between the Itata and Biobío Rivers shows a freshwater surface layer with salinity < 32.5 and 5-10 m thick during major plume events in 2002, 2005 and 2006. Surface salinity minima are correlated with peaks in turbidy from the normalized water leaving radiance at 555 nm (nLw(555)), both representing turbid river plumes. EOF analysis reveals that major turbid plume events occurred primarily during warm phases of the ENSO and PDO, and negative phases of the AAO, when storm tracks are further north. Anomalously large turbid plumes extend long distances offshore (∼ 70-80 km), and individual plumes coalesce into a continuous plume along the coast that covers the entire continental shelf. Season-specific correlation analyses reveal an increased influence of the AAO on river plumes south of Punta Lavapié in spring-summer (negative correlation). North of this major cape, ENSO and PDO indices have a dominant influence on plumes with positive correlations with the nLw(555) signal in winter (and negative in summer). We discuss the biogeochemical implications of plume events and the importance of long-term and high-resolution ocean color observations for studying the temporal evolution of river plumes.

  9. Recruitment Dynamics of the Relict Palm, Jubaea chilensis: Intricate and Pervasive Effects of Invasive Herbivores and Nurse Shrubs in Central Chile.

    PubMed

    Fleury, Marina; Marcelo, Wara; Vásquez, Rodrigo A; González, Luis Alberto; Bustamante, Ramiro O

    2015-01-01

    Shrubs can have a net positive effect on the recruitment of other species, especially relict species in dry-stressful conditions. We tested the effects of nurse shrubs and herbivory defoliation on performance (survival and growth) of nursery-grown seedlings of the largest living palm, the relict wine palm Jubaea chilensis. During an 18-month period, a total of more than 300 seedlings were exposed to of four possible scenarios produced by independently weakening the effects of nurse shrubs and browsers. The experiment followed a two-way fully factorial design. We found consistent differences in survival between protected and unprotected seedlings (27.5% and 0.7%, respectively), and herbivory had a dramatic and overwhelmingly negative effect on seedling survival. The invasive rabbit (Oryctolagus cuniculus) is clearly creating a critical bottleneck in the regeneration process and might, therefore, partially explain the general lack of natural regeneration of wine palms under natural conditions. Apparently biotic filters mediated by ecological interactions are more relevant in the early stages of recruitment than abiotic, at least in invaded sites of central Chile. Our data reveal that plant-plant facilitation relationship may be modulated by plant-animal interactions, specifically by herbivory, a common and widespread ecological interaction in arid and semi-arid environments whose role has been frequently neglected. Treatments that protect young wine palm seedlings are mandatory to enable the seedlings to attain a height at which shoots are no longer vulnerable to browsing. Such protection is an essential first step toward the conservation and reintroduction of this emblematic and threatened species. PMID:26218100

  10. Temporal and spatial variability of biological nitrogen fixation off the upwelling system of central Chile (35-38.5°S)

    NASA Astrophysics Data System (ADS)

    Fernandez, Camila; González, Maria Lorena; Muñoz, Claudia; Molina, Veronica; Farias, Laura

    2015-05-01

    Although N2 fixation could represent a supplementary source of bioavailable nitrogen in coastal upwelling areas and underlying oxygen minimum zones (OMZs), the limited data available prevent assessing its variability and biogeochemical significance. Here we report the most extensive N2 fixation data set gathered to date in the upwelling area off central Chile (36°S). It covers interannual to high frequency time scales in an area of about 82,500 km2 in the eastern South Pacific (ESP). Because heterotrophic N2 fixation may be regulated by DOM availability in the ESP, we conducted experiments at different oxygen conditions and included DOM amendments in order to test diazotrophic activity. Rates in the euphotic zone showed strong temporal variability which resulted in values reaching 0.5 nmol L-1 d-1 in 2006 (average 0.32 ± 0.17 nmol L-1 d-1) and up to 126.8 nmol L-1 d-1 (average 24.75 ± 37.9 nmol L-1 d-1) in 2011. N2 fixation in subsurface suboxic conditions (1.5 ± 1.16 nmol L-1 d-1) also occurred mainly during late summer and autumn while virtually absent in winter. The diversity of diazotrophs was dominated by heterotrophs, with higher richness in surface compared to OMZ waters. Rates in oxygen depleted conditions could exceed values obtained in the euphotic layer, but rates were not dependent on the availability of dissolved organic matter. N2 fixation also showed a positive correlation with total chlorophyll and the C:N ratio of phytoplankton, but not to the P excess compared to N. We conclude that the diazotrophic community responds to the composition of phytoplankton rather than the extent of N deficiency and the availability of bulk DOM in this system.

  11. Chronologic implications of new Miocene mammals from the Cura-Mallín and Trapa Trapa formations, Laguna del Laja area, south central Chile

    NASA Astrophysics Data System (ADS)

    Flynn, John J.; Charrier, Reynaldo; Croft, Darin A.; Gans, Phillip B.; Herriott, Trystan M.; Wertheim, Jill A.; Wyss, André R.

    2008-12-01

    Recent work in the central Andean Main Range of Chile near Laguna del Laja (˜37.5°S, 71°W) has produced the first mammal fossils for the region. Fossils, locally abundant and well preserved, occur patchily across a wide area southeast of the lake. Mammalian remains are derived from generally strongly folded (kilometer-scale) exposures of the locally ˜1.8 km thick, early to middle Miocene Cura-Mallín Formation; two identifiable specimens have been recovered from the overlying Trapa Trapa Formation as well. Both formations consist primarily of well-stratified (1-5 m thick layers) volcaniclastic and volcanic strata, deposited predominantly in fluviatile systems. The Cura-Mallín Formation is possibly the southern continuation of (or lateral equivalent to) the richly fossiliferous Abanico Formation mapped between ˜32°S and 36°S. Intensive sampling in a series of localities east and south of Laguna del Laja has yielded diverse faunas, in addition to radioisotopically dateable horizons. The new fossil mammal faunas represent as many as six South American Land Mammal "Ages" (SALMAs). Fossils, together with preliminary 40Ar/ 39Ar radioisotopic dates, ranging from ˜9 to 20 Ma across the exposed thickness of the Cura-Mallín Formation and into the overlying Trapa Trapa Formation, provide a robust geochronological framework for middle Cenozoic strata in the Laguna del Laja region. The sequence of directly superposed mammalian assemblages at Laguna del Laja is one of the longest in all of South America, rivaled only by the classic Gran Barranca section of Patagonian Argentina. These data illuminate the geological history of the area and its record of mammalian evolution. The potential to isotopically date these diverse faunas with high precision (error ± 0.5 Ma) presents a rare opportunity to calibrate related portions of the SALMA sequence.

  12. Construction of an Upper Crustal Reservoir by Lateral Magma Propagation: New insights from Geochronological Data of La Gloria Pluton, Central Chile

    NASA Astrophysics Data System (ADS)

    Gutiérrez, F. J.; Guillong, M.; Payacán, I. J.; Aravena, A.; Bachmann, O.; Parada, M. A.

    2014-12-01

    La Gloria Pluton (LGP) is a 10 Ma shallow elongated NNW reservoir of 17 km length and 4-6 km width as part of a NS trend of Miocene plutons in Central Chile. New LA-ICPMS U-Pb ages in zircons of La Gloria Pluton indicate that crystallization occurs mostly within an interval between 11.2 to 10 Ma, with southeastward decreasing ages. Zircon crystallization ages are consistently older at the boundaries of the pluton than at the center for a given cross-section. At regional scale the ages of LGP follows a plutonic trend of southward decreasing age: Estero Yerba Loca (10 Ma) and San Francisco Batholith (SFB), in the north; and Cerro Mesón Alto (12.5 Ma) and San Gabriel (SG; 13 Ma), in the south. Both regional and local (within-LGP) age trends suggest: 1) a progressive northward migration of the main deep magmatic source during the Miocene; and 2) a southeastward lateral propagation of the magma during the reservoir construction. The lateral propagation of the magma is also supported by subhorizontal mineral and magnetic lineations with a preferred NNW orientation within LGP. The within-pluton age distribution and internal configuration suggest incremental construction with horizontal propagation of magma within channels. Because the lateral migration of the magma play an important role on the thermal structure of the cooling pluton we perform numerical simulations that account for reheating caused by refilling along the axial core of the pluton . We speculate that pre-existing shallow crustal structures (faults and folds) would allow lateral magma canalization, particularly between the lower highly deformed volcanic Abanico Fm. and the less deformed overlaying volcanic Farellones Fm. The pluton distribution and internal organization in and around LGP suggest incremental construction with vertical and horizontal migration of magma within channels and reservoirs, yielding plutonic complexes with protracted ages and elongated geometries.

  13. Comparison of Tsunami Deposits Surveyed in 2010 and 2015 From the 2010 Maule Earthquake and Tsunami in South-Central Chile.

    NASA Astrophysics Data System (ADS)

    Ruiz, A. C.; MacInnes, B. T.; Ely, L. L.; Cisternas, M. A.; Gelfenbaum, G. R.; Richmond, B. M.; Meneses, D. J.

    2015-12-01

    The February 27, 2010 Mw 8.8 Maule earthquake and tsunami that struck south-central Chile altered the coastal landscape, leaving a depositional record at many locations along the coast. Our research is questioning whether tsunami deposits originally described during post-tsunami surveys in La Trinchera, Constitución and Coliumo soon after the event change significantly over time. The deposits initially described in 2010 were revisited 5 years later to determine if taphonomic changes occurred and to assess the long-term preservation potential of deposits with different initial characteristics and settings. We recently made measurements of deposit thickness, grain size, grading, sedimentary structures, incipient soil development and accumulation of organic material. Results indicate that deposit thickness and the maximum inland extent of recognizable deposits had decreased slightly since 2010, while overlying soil development and accumulation of organic matter increased. Few deposits had been altered by bioturbation. We will use the inland extent of the deposits surveyed in 2015 to model a minimum size of the 2010 earthquake and tsunami in GeoClaw. The results will be compared with independent geophysical models of the rupture characteristics. This can be used as a case study that can be applied to earlier paleo-earthquake and tsunami events in which seismic data is sparse or non-existent and the most reliable record is the inundation distance as determined by tsunami deposits. Studying the change of deposits in the geologic record over time can provide key insights into how tsunami deposits are preserved, which is important when working with paleo-deposits that may have been altered since deposition.

  14. The genetic relationship between mafic dike swarms and plutonic reservoirs in the mesozoic of central chile (30°-33°45'S): insights from AMS and geochemistry

    NASA Astrophysics Data System (ADS)

    Creixell, Christian; Parada, Miguel Ángel; Morata, Diego; Roperch, Pierrick; Arriagada, César

    2009-02-01

    Five mafic dike swarms between 30° and 33°45'S were studied for their geochemical signature and kinematics of magma flow directions by means of AMS data. In the Coastal Range of central Chile (33°-33°45'S), Middle Jurassic dike swarms (Concón and Cartagena dike swarms, CMDS and CrMDS, respectively) and an Early Cretaceous dike swarm (El Tabo Dike Swarm, ETDS) display the presence of dikes of geochemically enriched (high-Ti) and depleted (low-Ti) basaltic composition. These dikes show geochemical patterns that are different from the composition of mafic enclaves of the Middle Jurassic Papudo-Quintero Complex, and this suggests that the dikes were injected from reservoirs not related to the plutonic complex. The mantle source appears to be a depleted mantle for Jurassic dikes and a heterogeneous-enriched lithospheric mantle for Cretaceous dikes. In the ETDS, vertical and gently plunging magma flow vectors were estimated for enriched and depleted dikes, respectively, which suggest, together with variations in dike thickness, that reservoirs were located at different depths for each dike family. In the Elqui Dike Swarm (EDS) and Limarí Mafic Dike Swarm (LMDS), geochemical patterns are similar to those of the mafic enclaves of the Middle Jurassic plutons. In the LMDS, east to west magma flow vectors are coherent with injection from neighbouring pluton located to the east. In the EDS, some dikes show geochemical and magma flow patterns supporting the same hypothesis. Accordingly, dikes do not necessarily come from deep reservoir; they may propagate in the upper crust from coeval shallow pluton chamber.

  15. Cenozoic uplift of the Central Andes in northern Chile and Bolivia - reconciling paleoaltimetry with the geological evolution.

    NASA Astrophysics Data System (ADS)

    Lamb, S. H.

    2015-12-01

    The Cenozoic geological evolution of the Central Andes, along two transects between ~17.5°S and 21°S, is compared with paleo-topography, determined from published paleo-altimetry studies. Surface and rock uplift are quantified using simple 2-D models of crustal shortening and thickening, together with estimates of sedimentation, erosion and magmatic addition. Prior to ~25 Ma, during a phase of amagmatic flat-slab subduction, thick skinned crustal shortening and thickening was focused in the Eastern and Western Cordilleras, separated by a broad basin up to 300 km wide and close to sea level, which today comprises the high Altiplano. Surface topography in the Eastern Cordillera appears to be ~1 km lower than anticipated from crustal thickening, which may be due to the pull-down effect of the subducted slab, coupled to the overlying lithosphere by a cold mantle wedge. Oligocene steepening of the subducted slab is indicated by the initiation of the volcanic arc at ~27 - 25 Ma, and widespread mafic volcanism in the Altiplano between 25 and 20 Ma. This may have resulted in detachment of mantle lithosphere and possibly dense lower crust, triggering 1 - 1.5 km of rapid uplift (over << 5 Myrs) of the Altiplano and western margin of the Eastern Cordillera and establishing the present day lithospheric structure beneath the high Andes. Since ~25 Ma, surface uplift has been the direct result of crustal shortening and thickening, locally modified by the effects of erosion, sedimentation and magmatic addition from the mantle. The rate of crustal shortening and thickening varies with location and time, with two episodes of rapid shortening in the Altiplano, lasting < 5 Myrs, that are superimposed on a long term history of ductile shortening in the lower crust, driven by underthrusting of the Brazilian Shield on the eastern margin.

  16. The October 15, 1997 Punitaqui earthquake (Mw=7.1): a destructive event within the subducting Nazca plate in central Chile

    NASA Astrophysics Data System (ADS)

    Pardo, Mario; Comte, Diana; Monfret, Tony; Boroschek, Rubén; Astroza, Maximiliano

    2002-02-01

    The 1943 Illapel seismic gap, central Chile (30-32°S), was partially reactivated in 1997-1998 by two distinct seismic clusters. On July 1997, a swarm of offshore earthquakes occurred on the northern part of the gap, along the coupled zone between Nazca and South American plates. Most of the focal mechanisms computed for these earthquakes show thrust faulting solutions. The July 1997 swarm was followed on October 15, 1997 by the Punitaqui main event (Mw=7.1), which destroyed the majority of adobe constructions in Punitaqui village and its environs. The main event focal mechanism indicates normal faulting with the more vertical plane considered as the active fault. This event is located inland at 68-km depth and it is assumed to be within the oceanic subducted plate, as are most of the more destructive Chilean seismic events. Aftershocks occurred mainly to the north of the Punitaqui mainshock location, in the central-eastern part of the Illapel seismic gap, but at shallower depths, with the two largest showing thrust focal mechanisms. The seismicity since 1964 has been relocated with a master event technique and a Joint Hypocenter Determination (JHD) algorithm, using teleseismic and regional data, along with aftershock data recorded by a temporary local seismic network and strong motion stations. These data show that the 1997 seismic clusters occurred at zones within the Illapel gap where low seismicity was observed during the considered time period. The analysis of P and T axis directions along the subduction zone, using the Harvard Centroid Moment Tensor solutions since 1977, shows that the oceanic slab is in a downdip extensional regime. In contrast, the Punitaqui mainshock is related to compression resulting from the flexure of the oceanic plate, which becomes subhorizontal at depths of about 100 km. Analog strong motion data of the Punitaqui main event show that the greatest accelerations are on the horizontal components. The highest amplitude spectra of the

  17. Common catabolic enzyme patterns in a microplankton community of the Humboldt Current System off northern and central-south Chile: Malate dehydrogenase activity as an index of water-column metabolism in an oxygen minimum zone

    NASA Astrophysics Data System (ADS)

    González, R. R.; Quiñones, R. A.

    2009-07-01

    An extensive subsurface oxygen minimum zone off northern and central-south Chile, associated with the Peru-Chile undercurrent, has important effects on the metabolism of the organisms inhabiting therein. Planktonic species deal with the hypoxic and anoxic environments by relying on biochemical as well as physiological processes related to their anaerobic metabolisms. Here we characterize, for the first time, the potential enzymatic activities involved in the aerobic and anaerobic energy production pathways of microplanktonic organisms (<100 μm), their relationship, and this relationship's association with the oxygen concentration and microplanktonic biomass in the oxygen minimum zone and adjacent areas of the Humboldt Current System water column. Our results demonstrate significant potential enzymatic activity of catabolic pathways in the oxygen minimum zone. Malate dehydrogenase had the highest oxidizing activity of nicotinamide adenine dinucleotide (reduced form) in the batch of catabolic enzymatic activities assayed, including potential pyruvate oxidoreductases activity, the electron transport system, and dissimilatory nitrate reductase. Malate dehydrogenase correlated significantly with almost all the enzymes analyzed within and above the oxygen minimum zone, and also with the oxygen concentration and microplankton biomass in the water column of the Humboldt Current System, especially in the oxygen minimum zone off Iquique. These results suggest a possible specific pattern for the catabolic activity of the microplanktonic realm associated with the oxygen minimum zone spread along the Humboldt Current System off Chile. We hypothesize that malate dehydrogenase activity could be an appropriate indicator of microplankton catabolism in the oxygen minimum zone and adjacent areas.

  18. Oroclinal bending of the Juan Fernández Ridge suggested by geohistory analysis of the Bahía Inglesa Formation, north-central Chile

    NASA Astrophysics Data System (ADS)

    Le Roux, Jacobus P.; Achurra, Luciano; Henríquez, Álvaro; Carreño, Catalina; Rivera, Huber; Suárez, Mario E.; Ishman, Scott E.; Pyenson, Nicholas D.; Gutstein, Carolina S.

    2016-03-01

    The stratigraphy of the Bahía Inglesa Formation in the Caldera Basin west of Copiapó, (north-central Chile) is revised, based on hitherto unpublished stratigraphic sections and 87Sr/86Sr dating. The depositional environment varied from a rocky shoreline to the upper continental slope, with sea-level oscillations and tectonic movements causing numerous local unconformities as well as lateral and vertical facies changes. Geohistory and sedimentological analyses show that the area was close to the concurrent sea level at about 15.3 Ma, but at the same time being elevated about 100 m above the present sea level. Although the basin then subsided at least 350 m until around 6 Ma, marine deposition was only recorded after 10.4 Ma. This suggests that the sea level initially dropped faster than the rate of subsidence so that subaerial erosion occurred. The period of subaerial exposure before 10.4 Ma can be attributed to the presence of a NE-trending branch of the Juan Fernández Ridge below the continental crust at this time, whereas the ensuing subsidence was due to subduction erosion and crustal accommodation in its wake as it migrated south along the South American coastline. The subsequent uplift of at least 250 m can be explained by an acceleration in plate expansion and isostatic rebound of the continental crust after being partially submerged in the upper mantle. The uplift-subsidence-uplift pattern mirrors those recorded around the Nazca Ridge in Peru, as well as in similar basins to the south of Caldera. However, a higher southward migration rate of the Juan Fernández Ridge against the edge of the South American Plate and less intense uplift-subsidence-uplift cycles are recorded in the latter basins. This can possibly be attributed to oroclinal bending of the ridge due to friction with the overlying continental plate, which diminished the angle of incidence and the intensity of the stress field, but increased the migration velocity of the ridge relative to the

  19. New evidence for late mesozoic-early Cenozoic evolution of the Chilean Andes in the upper Tinguiririca valley (35 °S), central Chile

    NASA Astrophysics Data System (ADS)

    Charrier, Reynaldo; Wyss, AndréR.; Flynn, John J.; Swisher, Carl C.; Norell, Mark A.; Zapatta, Franyo; McKenna, Malcolm C.; Novacek, Michael J.

    1996-11-01

    New geologic, paleontologic and isotopic geochronometric results from the Termas del Flaco region in the upper Tinguiririca River valley in central Chile demand considerable revision of the accepted geotectonic history of the Andean Main Range in this region. A diverse, transitional Eocene-Oligocene aged, land-mammal fauna was recovered from several sites in volcaniclastic sediments of the Coya-Machalí (=Abanico) Formation. Major results of our study include: 1) The 1000 + m thick studied deposits, previously attributed to the Cretaceous Colimapu Formation, belong to the Coya-Machalí (=Abanico) Formation. Radioisotopic data from levels immediately above (31.5 Ma) and below (37.S Ma) the fossiliferous horizon indicate a latest Eocene to early Oligocene age for the basal part of the formation and the fauna contained in it. 2) The fossiliferous unit rests with slight angular offset on different Mesozoic units: "Brownish-red Clastic Unit" (BRCU) and Baños del Flaco Formation; in a limited area it also overlies a white tuff dated at 104 Ma. 3) The contacts just discussed (none of which is attributable to faulting), demonstrate the existence of two, or possibly three, unconformities in the region. 4) Sedimentological criteria argue against reference of the BRCU to the Colimapu Formation, and imply correlation of the former unit to basal levels with in the late Cretaceous Neuquén Group of western Argentina. 5) The Coya-Machalí Formation, previously viewed as representing the western volcanic equivalent of Riográndico Supercycle deposits of western Argentino, is likely coeval to much younger units in that region such as the Agua de la Piedra Formation. 6) Paleomagnetic results from the fossil producing horizon indicate about 20 ° of post-early Oligocene, counterclockwise rotation. 7) Fossil mammals from the Coya-Machalí Formation near Termas del Flaco represent a distinct biochronologic interval not heretofore clearly recognized from elsewhere on the continent

  20. Presence of nitrous oxide hotspots in the coastal upwelling area off central Chile: an analysis of temporal variability based on ten years of a biogeochemical time series

    NASA Astrophysics Data System (ADS)

    Farías, L.; Besoain, V.; García-Loyola, S.

    2015-04-01

    Seasonal and inter-annual variabilities of biogeochemical variables, including nitrous oxide (N2O), an important climate active gas, were analyzed during monthly observations between 2002 and 2012 at an ocean Time-Series station in the coastal upwelling area off central Chile (36° 30.8‧ 73° 15‧). Oxygen, N2O, nutrients and chlorophyll-a (Chl-a) showed clear seasonal variability associated with upwelling favorable winds (spring-summer) and also inter-annual variability, which in the case of N2O was clearly observed during the occurrence of N2O hotspots with saturation levels of up to 4849%. These hotspots consistently took place during the upwelling-favorable periods in 2004, 2006, 2008, 2010 and 2011, below the mixed layer (15-50 m depth) in waters with hypoxia and some N{{O}2}- accumulation. The N2O hotspots displayed excesses of N2O (ΔN2O) three times higher than the average monthly anomalies (2002-2012). Estimated relationships of ΔN2O versus apparent oxygen utilization (AOU), and ΔN2O versus N{{O}3}-, suggest that aerobic ammonium oxidation (AAO) and partial denitrification are the processes responsible for high N2O accumulation in subsurface water. Chl-a levels were reasonably correlated with the presence of the N2O hotspots, suggesting that microbial activities fuelled by high availability of organic matters lead to high N2O production. As a result, this causes a substantial N2O efflux into the atmosphere of up to 260 μmol m-2 d-1. The N2O hotspots are transient events or hot moments, which may occur more frequently than they are observed. If so, this upwelling area is producing and emitting greater than expected amounts of N2O and is therefore an important N2O source that should be considered in the global atmospheric N2O balance.

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

    NASA Astrophysics Data System (ADS)

    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

  2. Subduction of the South Chile active spreading ridge: A 17 Ma to 3 Ma magmatic record in central Patagonia (western edge of Meseta del Lago Buenos Aires, Argentina)

    NASA Astrophysics Data System (ADS)

    Boutonnet, E.; Arnaud, N.; Guivel, C.; Lagabrielle, Y.; Scalabrino, B.; Espinoza, F.

    2010-01-01

    The Chile Triple Junction is a natural laboratory to study the interactions between magmatism and tectonics during the subduction of an active spreading ridge beneath a continent. The MLBA plateau (Meseta del Lago Buenos Aires) is one of the Neogene alkali basaltic plateaus located in the back-arc region of the Andean Cordillera at the latitude of the current Chile Triple Junction. The genesis of MLBA can be related with successive opening of slabs windows beneath Patagonia: within the subducting Nazca Plate itself and between the Nazca and Antarctic plates. Detailed 40Ar/ 39Ar dating and geochemical analysis of bimodal magmatism from the western flank of the MLBA show major changes in the back-arc magmatism which occurred between 14.5 Ma and 12.5 Ma with the transition from calc-alkaline lavas (Cerro Plomo) to alkaline lavas (MLBA) in relation with slab window opening. In a second step, at 4-3 Ma, alkaline felsic intrusions were emplaced in the western flank of the MLBA coevally with the MLBA basalts with which they are genetically related. These late OIB-like alkaline to transitional basalts were generated by partial melting of the subslab asthenosphere of the subducting Nazca plate during the opening of the South Chile spreading ridge-related slab window. These basalts differentiated with small amounts of assimilation in shallow magma chambers emplaced along transtensional to extensional zones. The close association of bimodal magmatism with extensional tectonic features in the western MLBA is a strong support to the model of Patagonian collapse event proposed to have taken place between 5 and 3 Ma as a consequence of the presence of the asthenospheric window (SCR-1 segment of South Chile Ridge) below the MLBA area.

  3. Using (137)Cs and (210)Pbex and other sediment source fingerprints to document suspended sediment sources in small forested catchments in south-central Chile.

    PubMed

    Schuller, P; Walling, D E; Iroumé, A; Quilodrán, C; Castillo, A; Navas, A

    2013-10-01

    A study of the impact of forest harvesting operations on sediment mobilization from forested catchments has been undertaken in south-central Chile. The study focused on two sets of small paired catchments (treatment and control), with similar soil type, but contrasting mean annual rainfall, located about 400 km apart at Nacimiento (1200 mm yr(-1)) and Los Ulmos (2500 mm yr(-1)). The objective was to study the changes in the relative contribution of the primary sources of fine sediment caused by forestry operations. Attention focused on the pre-harvest and post-harvest periods and the post-replanting period was included for the Nacimiento treatment catchment. The sediment source fingerprinting technique was used to document the contributions of the potential sources. Emphasis was placed on discriminating between the forest slopes, forest roads and channel erosion as potential sources of fine sediment and on assessing the relative contributions of these three sources to the sediment yield from the catchments. The fallout radionuclides (FRNs) (137)Cs and excess lead-210, the environmental radionuclides (226)Ra and (40)K and soil organic matter (SOM) were tested as possible fingerprints for discriminating between potential sediment sources. The Kruskal-Wallis test and discriminant function analysis were used to guide the selection of the optimum fingerprint set for each catchment and observation period. Either one or both of the FRNs were selected for inclusion in the optimum fingerprint for all datasets. The relative contribution of each sediment source to the target sediment load was estimated using the selected fingerprint properties, and a mixing model coupled with a Monte Carlo simulation technique that takes account of uncertainty in characterizing sediment source properties. The goodness of fit of the mixing model was tested by comparing the measured and simulated fingerprint properties for the target sediment samples. In the Nacimiento treatment catchment

  4. The Donoso copper-rich, tourmaline-bearing breccia pipe in central Chile: petrologic, fluid inclusion and stable isotope evidence for an origin from magmatic fluids

    NASA Astrophysics Data System (ADS)

    Skewes, M. Alexandra; Holmgren, Carmen; Stern, Charles R.

    2003-01-01

    The copper-rich, tourmaline-bearing Donoso breccia pipe is one among more than 15 different mineralized breccias in the giant (>50 million metric tonnes of copper) Miocene and Pliocene Río Blanco-Los Bronces copper deposit in the high Andes of central Chile. This breccia pipe, bracketed in age between 5.2 and 4.9 Ma, has dimensions of 500 by 700 m at the current surface 3,670 m above sea level. Its roots have yet to be encountered, and it is >300 m in diameter at the depth of the deepest drill holes. The Donoso breccia is, for the most part, monolithic, containing clasts of the equigranular quartz monzonite pluton which hosts the pipe. It is matrix supported, with between 5 and 25% of the total rock volume consisting of breccia-matrix minerals, which include tourmaline, quartz, chalcopyrite, pyrite, specularite, and lesser amounts of bornite and anhydrite. An open pit mine, centered on this breccia pipe, has a current production of 50,000 tonnes of ore per day at an average grade of 1.2% copper, and copper grade in the breccia matrix is significantly higher. Measured δ18O for tourmaline and quartz from the matrix of the Donoso breccia at different levels of the pipe range from +6.9 to +12.0‰, and measured δD in tourmaline ranges from -73 to -95‰. Temperatures of crystallization of these minerals, as determined by the highest homogenization temperatures of highly saline fluid inclusions, range from 400 to >690°C. When corrected for these temperatures, the stable isotope data indicate that fluids from which these breccia-matrix minerals precipitated were magmatic, with δ18O between +5.6 to +9.1‰ and δD between -51 to -80‰. These isotopic data preclude participation of a significant amount of meteoric water in the formation of the Donoso breccia. They support a model in which brecciation is caused by expansion of magmatic fluids exsolved from a cooling pluton, and breccia-matrix minerals, including copper sulfides, precipitated from the same magmatic

  5. Detailed geologic field mapping and radiometric dating of the Abanico Formation in the Principal Cordillera, central Chile: Evidence of protracted volcanism and implications for Cenozoic tectonics

    NASA Astrophysics Data System (ADS)

    Mosolf, J.; Gans, P. B.; Wyss, A. R.; Cottle, J. M.

    2011-12-01

    Many aspects of the long-term evolution of intra-arc processes remain poorly understood, including temporal trends in magmatism, temporal and spatial patterns of volcanism, and styles of arc deformation. The Abanico Formation in the Principal Cordillera of central Chile is a thick, well-exposed section of volcanogenic strata providing a superb locale for the investigation of continental arc dynamics over a 60+ myr timescale. In this study, eight new litho-stratigraphic members of the Abanico Formation are described and mapped in the Río Tinguiririca river area. Mapping and field observations show the Abanico Formation measures up to ~2.5 km in composite stratigraphic thickness. The lower ~1.1 km of the section (> 46 Ma) is dominated by andesitic breccias interbedded with andesite, basaltic andesite, and olivine basalt lavas. The upper 1.4 km of the section (< 46 Ma) consists of volcaniclastic sandstone interbedded with abundant dacitic tuffs and minor andesite, basaltic andesite, and basalt flows. Nineteen new LA-MC-ICPMS U-Pb zircon ages and ten new 40Ar/39Ar whole rock and plagioclase ages obtained for the Abanico Formation clarify ambiguous field relationships and provide a robust chrono-stratigraphic framework spanning ~72 to 11 Ma; these new ages significantly revise the maximum mid-Tertiary age for the Abanico Formation previously established by the mammal fossil record. The map units are cut by numerous dacitic to gabbroic dikes and sills with ages spanning the Eocene to Pliocene. The Abanico Formation is overlain in angular unconformity by Pliocene and Quaternary volcanics composed mainly of andesite, basaltic andesite, and basalt lavas. A strong deformational overprint has tilted, folded, and faulted the Abanico map units. Fold axes and reverse faults, both east and west directed, are generally N-S trending. Reverse faults achieve up to ~50 Ma of stratigraphic separation, placing Campanian strata on Miocene rocks with up to ~2 km of vertical throw. The

  6. Consistent magmatic and magnetic anisotropy data in La Gloria Pluton, central Chile: Implications for the magma flow record in a shallow pluton

    NASA Astrophysics Data System (ADS)

    Payacan, I.; Gutierrez, F. J.; Bachmann, O.; Parada, M.

    2012-12-01

    The magmatic origin of the anisotropy of magnetic susceptibility (AMS) is examined in comparison with magmatic anisotropy data in a small, shallow, silicic magma reservoir in the upper crust. La Gloria Pluton (LGP) is a 10 Ma granodiorite/quartz monzonite of about 250 km3 located in the southern Andes, central Chile. LGP represents a particularly simple case of a silicic intrusion which was assembled in a few pulses and cooled over a short time interval. Hornblende, biotite and minor magnetite are ubiquitous mafic phases. The AMS tensor indicates that magnetic fabric has an oblate shape (i.e. magnetic foliation is higher than magnetic lineation). Lineations are weak (values up to 1.05), have a N-NW trend with a nearly horizontal dip and represent axisymmetric convection parallel to the main pluton elongation. Foliations are more pronounced (values up to 1.14), having NW trends and dips that vary gradually from vertical at the walls, to horizontal at the center and near the roof of the chamber. We interpret this to represent shear localization near the magma locking point along solidification fronts. Magmatic anisotropy data were obtained by measuring mineral length, width and orientation in the three main planes of the AMS tensor. We define the planes Pmax, Pint, and Pmin as orthogonal to the maximum, intermediate, and minimum axes of the AMS tensor, respectively. Mineral data were collected for plagioclase and amphibole + bitotite independently. For each site, the Bingham distribution with 95% of confidence is used to determine the mean mineral orientation and their angle difference with the AMS axes. Preliminary results indicate that mean crystal orientations are well defined for Pmax and Pint for all analyzed minerals, but Pmin is only well constrained for amphibole + bitotite and poorly constrained for plagioclase. Angle differences generally decrease with magnetic anisotropy but are independent of the size and aspect ratio of the crystals. Mean values of

  7. Seismology in Chile

    USGS Publications Warehouse

    Kausel, E.

    1983-01-01

    The Department of Geology and Geophysics, which is under the faculties of Mathematics and Physical Sciences of the University of Chile, is the organization that is responsible for the Seismological Service of Chile and for installing,operating, and maintaining the seismological stations as well as all the strong-motion stations in Chile.

  8. Evidence for Cenozoic extensional basin development and tectonic inversion south of the flat-slab segment, southern Central Andes, Chile (33° 36°S.L.)

    NASA Astrophysics Data System (ADS)

    Charrier, R.; Baeza, O.; Elgueta, S.; Flynn, J. J.; Gans, P.; Kay, S. M.; Muñoz, N.; Wyss, A. R.; Zurita, E.

    2002-04-01

    The mainly volcanic Cenozoic deposits that make up much of the western part of the Principal Cordillera in Central Chile are generally subdivided into two major units: an older Abanico or Coya-Machalı´ Formation and a younger Farellones Formation. Difficulty in differentiating these units has led to considerable debate. On the basis of the wide distribution, great thickness, and presence of sedimentary intercalations, it has been postulated that these arc volcanics were deposited in an intermontane basin; more recently, it has been proposed that this basin developed under extensional conditions and underwent subsequent tectonic inversion. We present field, geochronologic, geochemical, and thermal maturity data that support the latter interpretation. Collectively, this new information clarifies the stratigraphic, tectonic, and paleogeographic evolution of these deposits. The vast geographic extent of the Abanico Formation and lateral equivalents, which reach from at least 32°30' to 44°S along the Principal Cordillera, its great thickness, and the presence of repeated thick fluvial and lacustrine intercalations all indicate deposition in a large, strongly subsident, and probably north-south oriented basin, developed between middle to late Eocene and Oligocene. The unconformable contact with underlying Mesozoic units observed at several localities indicates that deposition followed a substantial erosional episode during late Cretaceous and/or early Cenozoic time. Basal deposits of the Abanico Formation near Termas del Flaco increase rapidly in thickness to the west. Still further to the west, a thick Abanico section contains, in its upper part, mammal fossils older than those found in the basal deposits near Termas. This evidence indicates a major space of deposition west of this locality, which had been filled before deposition took place at Termas. The east-vergent, high-angle El Fierro thrust fault on the east side of the westward-growing deposits is

  9. 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

    NASA Astrophysics Data System (ADS)

    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.

  10. Lacustrine records of the June 2011 eruption of the Puyehue-Cordón Caulle Volcanic Complex, Central Chile (40°30'S, 72°10'W)

    NASA Astrophysics Data System (ADS)

    Daga, Romina; Bertrand, Sébastien; Bedert, Robin; Ribeiro Guevara, Sergio; Ghazoui, Zakaria

    2013-04-01

    Present volcanic eruptions offer unique opportunities to study the dispersion and spatial variability of volcanic deposits. The objective of this work is to assess lateral variations of pyroclastic deposits from the June 2011 volcanic eruption of Puyehue-Cordon Caulle Volcanic Complex (PCCVC) by analyzing the sedimentology and geochemistry of tephra layers deposited in different lakes situated in North Patagonia (Chile and Argentina), located along the main dispersion axis of the volcanic cloud. Short sediment cores were extracted from selected lakes in Chile and Argentina using a short Uwitec gravity corer; coarse tephra deposits were collected with a grab sampler. The sediment cores were opened, visually inspected, photographed and described, and the magnetic susceptibility was measured with a Bartington MS3 meter and MS2E sensor. Visual inspection included the identification of the 2011 tephra layer, and the description of colour, grain size, thickness, and sedimentary structures of the sedimentary sequence. Subsequent studies were focused on the tephra layers. Samples were freeze-dried for multi-proxy analyses, including bulk mineralogy analyzed by X-ray diffraction and bulk geochemical characterization by Instrumental Neutron Activation Analysis. In this presentation, the main characterization features of the pyroclastic products will be presented, together with dispersion patterns. Lacustrine tephra deposits clearly reflected the predominance of westerlies, with thin deposits on the Chilean side of the volcano, but much thicker and coarser tephra close to the volcano. Ash dispersion extended hundreds of kilometers towards the east of the volcano, i.e., in Argentinean territory. Tephras deposited in water bodies in Chile are mainly transported from the eruptive center by rivers and watercourses with headwaters located in the volcano area, whereas tephra deposits in Argentinean lakes mainly result from direct ash falls. We also observed in-lakes variations in

  11. Late Oligocene-Early Miocene compressional tectosedimentary episode and associated land-mammal faunas in the Andes of central Chile and adjacent Argentina (32 37°s)

    NASA Astrophysics Data System (ADS)

    Semper, Thierry; Marshall, Larry G.; Rivano, Sergio; Godoy, Estanislao

    1994-01-01

    A reassessment of the geologic and land-mammal fossil evidence used in attribution of a tectosedimentary episode in the Andes between 32 and 37°S to the Middle Eocene "Incaic tectonic phase" of Peru indicates that the episode occurred during Late Oligocene-Early Miocene times(~ 27-20 Ma). From west to east, three structural domains are recognized for this time span in the study area: a volcanic arc (Chile); a thin-skinned, E-verging fold-thrust belt (Cordillera Principal, Chile-Argentina border strip); and a foreland basin (Argentina). Initiation of thrusting in the Cordillera Principal fold-thrust belt produced the coeval initiation of sedimentation in the foreland basin of adjacent Argentina. This onset of foreland deposition postdates strata bearing a Divisaderan Land Mammal Age fauna (i.e. ~ 35-30 Ma) and is marked at ~ 36°30'S by the base of the "Rodados Lustrosos" conglomerates, which are conformably overlain by sedimentary rocks containing a Deseadan Land Mammal Age fauna (i.e. ~ 29-21 Ma). Geologic relationships between the thick volcanic Abanico (Coya-Machalí) and Farellones formations also demonstrate that this tectosedimentary episode practically ended at ~ 20 Ma at least in the volcanic arc, and was therefore roughly coeval with the major tectonic crisis (~ 27-19 Ma) known in northwestern Andean Bolivia some 1500 km to the north. This strongly suggests that a long, outstanding tectonic upheaval affected at least an extended 12-37°S segment of the Andean margin of South America during Late Oligocene and Early Miocene times.

  12. Seasonal variability of the Ekman transport and pumping in the upwelling system off central-northern Chile (˜ 30° S) based on a high-resolution atmospheric regional model (WRF)

    NASA Astrophysics Data System (ADS)

    Bravo, Luis; Ramos, Marcel; Astudillo, Orlando; Dewitte, Boris; Goubanova, Katerina

    2016-09-01

    Two physical mechanisms can contribute to coastal upwelling in eastern boundary current systems: offshore Ekman transport due to the predominant alongshore wind stress and Ekman pumping due to the cyclonic wind stress curl, mainly caused by the abrupt decrease in wind stress (drop-off) in a cross-shore band of 100 km. This wind drop-off is thought to be an ubiquitous feature in coastal upwelling systems and to regulate the relative contribution of both mechanisms. It has been poorly studied along the central-northern Chile region because of the lack in wind measurements along the shoreline and of the relatively low resolution of the available atmospheric reanalysis. Here, the seasonal variability in Ekman transport, Ekman pumping and their relative contribution to total upwelling along the central-northern Chile region (˜ 30° S) is evaluated from a high-resolution atmospheric model simulation. As a first step, the simulation is validated from satellite observations, which indicates a realistic representation of the spatial and temporal variability of the wind along the coast by the model. The model outputs are then used to document the fine-scale structures in the wind stress and wind curl in relation to the topographic features along the coast (headlands and embayments). Both wind stress and wind curl had a clear seasonal variability with annual and semiannual components. Alongshore wind stress maximum peak occurred in spring, second increase was in fall and minimum in winter. When a threshold of -3 × 10-5 s-1 for the across-shore gradient of alongshore wind was considered to define the region from which the winds decrease toward the coast, the wind drop-off length scale varied between 8 and 45 km. The relative contribution of the coastal divergence and Ekman pumping to the vertical transport along the coast, considering the estimated wind drop-off length, indicated meridional alternation between both mechanisms, modulated by orography and the intricate

  13. The Amazon-Laurentian connection as viewed from the Middle Proterozoic rocks in the central Andes, western Bolivia and northern Chile

    USGS Publications Warehouse

    Tosdal, R.M.

    1996-01-01

    Middle Proterozoic rocks underlying the Andes in western Bolivia, western Argentina, and northern Chile and Early Proterozoic rocks of the Arequipa massif in southern Peru?? from the Arequipa-Antofalla craton. These rocks are discontinuously exposed beneath Mesozoic and Cenozoic rocks, but abundant crystalline clasts in Tertiary sedimentary rocks in the western altiplano allow indirect samples of the craton. Near Berenguela, western Bolivia, the Oligocene and Miocene Mauri Formation contains boulders of granodiorite augen gneiss (1171??20 Ma and 1158??12 Ma; U-Pb zircon), quartzose gneiss and granofels that are inferred to have arkosic protoliths (1100 Ma source region; U-Pb zircon), quartzofeldspathic and mafic orthogneisses that have amphibolite- and granulite-facies metamorphic mineral assemblages (???1080 Ma metamorphism; U-Pb zircon), and undeformed granitic rocks of Phanerozoic(?) age. The Middle Proterozoic crystalline rocks from Berenguela and elsewhere in western Bolivia and from the Middle Proterozoic Bele??n Schist in northern Chile generally have present-day low 206Pb/204Pb ( 15.57), and elevated 208Pb/204Pb (37.2 to 50.7) indicative of high time-averaged Th/U values. The Middle Proterozoic rocks in general have higher presentday 206Pb/204Pb values than those of the Early Proterozoic rocks of the Arequipa massif (206Pb/204Pb between 16.1 and 17.1) but lower than rocks of the southern Arequipa-Antofalla craton (206Pb/204Pb> 18.5), a difference inferred to reflect Grenvillian granulite metamorphism. The Pb isotopic compositions for the various Proterozoic rocks lie on common Pb isotopic growth curves, implying that Pb incorporated in rocks composing the Arequipa-Antofalla craton was extracted from a similar evolving Pb isotopic reservoir. Evidently, the craton has been a coherent terrane since the Middle Proterozoic. Moreover, the Pb isotopic compositions for the Arequipa-Antofalla craton overlap those of the Amazon craton, thereby supporting a link

  14. Geochemistry of trace metals in shelf sediments affected by seasonal and permanent low oxygen conditions off central Chile, SE Pacific (˜36°S)

    NASA Astrophysics Data System (ADS)

    Muñoz, Praxedes; Dezileau, Laurent; Cardenas, Lissette; Sellanes, Javier; Lange, Carina B.; Inostroza, Jorge; Muratli, Jesse; Salamanca, Marco A.

    2012-02-01

    Trace metals (Cd, U, Co, Ni, Cu, Ba, Fe, Mn), total organic carbon (TOC) and C and N stable isotope signatures (δ 13C and δ 15N) were determined in short sediments cores from the inner and outer shelf off Concepción, Chile (˜36°S). The objectives were to establish the effect of environmental conditions on trace metal distributions at two shelf sites, one affected by seasonal oxygenation and the other by permanent low oxygen conditions due to the presence of the oxygen minimum zone (OMZ). We evaluate trace metals as proxies of past changes in primary productivity and the bottom water oxygen regime. Concentrations of pore water sulfides and NH4+ were also measured as indicators of the main diagenetic pathways at each site. Our results for the inner shelf (seasonal suboxia) suggest that the oxidative state of the sediments responds to seasonal pulses of organic matter and that seasonal oxygenation develops during high and low primary productivity in the water column. Here, positive fluxes (to the water column) estimated from pore water concentrations of several elements were observed (Ba, Co, Ni, Fe and Mn). The less reduced environment at this site produces authigenic enrichment of Cu associated with the formation of oxides in the oxic surface sediment layer, and the reduction of U within deeper sediment sections occur consistently with negative estimated pore water fluxes. In the outer shelf sediments (permanent suboxia, OMZ site), negative fluxes (to the sediment) were estimated for all elements, but these sediments showed authigenic enrichments only for Cd, Cu and U. The short oxygenation period during the winter season did not affect the accumulation of these metals on the shelf. The distribution of Cu, Cd and U have been preserved within the sediments and the authigenic accumulation rates estimated showed a decrease from the deep sections of the core to the surface sediments. This could be explained by a gradual decrease in the strength of the OMZ in the

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

    NASA Astrophysics Data System (ADS)

    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

  16. 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

    NASA Astrophysics Data System (ADS)

    Martínez, F.; Maksymowicz, A.; Ochoa, H.; Díaz, D.

    2015-12-01

    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 synextensional deposits recognized within the basin, suggest that its structure 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.

  17. 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

    NASA Astrophysics Data System (ADS)

    Martínez, F.; Maksymowicz, A.; Ochoa, H.; Díaz, D.

    2015-08-01

    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.

  18. Genetic diversity and insecticide resistance during the growing season in the green peach aphid (Hemiptera: Aphididae) on primary and secondary hosts: a farm-scale study in Central Chile.

    PubMed

    Rubiano-Rodríguez, J A; Fuentes-Contreras, E; Figueroa, C C; Margaritopoulos, J T; Briones, L M; Ramírez, C C

    2014-04-01

    The seasonal dynamics of neutral genetic diversity and the insecticide resistance mechanisms of insect pests at the farm scale are still poorly documented. Here this was addressed in the green peach aphid Myzus persicae (Sulzer) (Hemiptera: Aphididae) in Central Chile. Samples were collected from an insecticide sprayed peach (Prunus persica L.) orchard (primary host), and a sweet-pepper (Capsicum annum var. grossum L.) field (secondary host). In addition, aphids from weeds (secondary hosts) growing among these crops were also sampled. Many unique multilocus genotypes were found on peach trees, while secondary hosts were colonized mostly by the six most common genotypes, which were predominantly sensitive to insecticides. In both fields, a small but significant genetic differentiation was found between aphids on the crops vs. their weeds. Within-season comparisons showed genetic differentiation between early and late season samples from peach, as well as for weeds in the peach orchard. The knock-down resistance (kdr) mutation was detected mostly in the heterozygote state, often associated with modified acetylcholinesterase throughout the season for both crops. This mutation was found in high frequency, mainly in the peach orchard. The super-kdr mutation was found in very low frequencies in both crops. This study provides farm-scale evidence that the aphid M. persicae can be composed of slightly different genetic groups between contiguous populations of primary and secondary hosts exhibiting different dynamics of insecticide resistance through the growing season. PMID:24484894

  19. Genetic diversity and insecticide resistance during the growing season in the green peach aphid (Hemiptera: Aphididae) on primary and secondary hosts: a farm-scale study in Central Chile.

    PubMed

    Rubiano-Rodríguez, J A; Fuentes-Contreras, E; Figueroa, C C; Margaritopoulos, J T; Briones, L M; Ramírez, C C

    2014-04-01

    The seasonal dynamics of neutral genetic diversity and the insecticide resistance mechanisms of insect pests at the farm scale are still poorly documented. Here this was addressed in the green peach aphid Myzus persicae (Sulzer) (Hemiptera: Aphididae) in Central Chile. Samples were collected from an insecticide sprayed peach (Prunus persica L.) orchard (primary host), and a sweet-pepper (Capsicum annum var. grossum L.) field (secondary host). In addition, aphids from weeds (secondary hosts) growing among these crops were also sampled. Many unique multilocus genotypes were found on peach trees, while secondary hosts were colonized mostly by the six most common genotypes, which were predominantly sensitive to insecticides. In both fields, a small but significant genetic differentiation was found between aphids on the crops vs. their weeds. Within-season comparisons showed genetic differentiation between early and late season samples from peach, as well as for weeds in the peach orchard. The knock-down resistance (kdr) mutation was detected mostly in the heterozygote state, often associated with modified acetylcholinesterase throughout the season for both crops. This mutation was found in high frequency, mainly in the peach orchard. The super-kdr mutation was found in very low frequencies in both crops. This study provides farm-scale evidence that the aphid M. persicae can be composed of slightly different genetic groups between contiguous populations of primary and secondary hosts exhibiting different dynamics of insecticide resistance through the growing season.

  20. Neotectonics In The Central Depression (atacama Desert, 25-26°s, Northern Chile) and Its Implications For Recent Sedimentary Fluxes and Regional Deformation

    NASA Astrophysics Data System (ADS)

    Audin, L.; Hérail, G.; Riquelme, R.; Darrozes, J.; Martinod, J.; Font, E.

    In the northern Chilean Andes, the Pampas Exploradora and Carizo are part of a NS- trending basin (known as the Central Depression) that separates the Coastal Range from the Precodillera. The Exploradora and Carizo region has undergone an extremely arid climate at least since the Middle Miocene time (~15 Ma ago). The limited extent of erosion, due to exceptional aridity, has greatly contributed to the preservation of the landform. In such environment the landforms can be very well used to analyse the tectonic evolution. A basin infilling occurred during the Cenozoic (Atacama Gravels) with the deposition of large volumes of coarse gravels coming from the Precordillera. The aggradation and filling of the paleo-drainage system by the Atacama Gravels of fluviatil origin mark an important erosive unconformity. Moreover, this uniform preserved surface has undergone low magnitude deformation during the deposition period. But we have evidenced a late and post Atacama Gravel tectonic episode. On the western side of the Precordillera a number of normal faults that cross a dense network of very well preserved channels and its alluvial fans. This tectonic deformation is not large in magnitude, about 2m of vertical offset, but clearly appear in the landscape suggesting that the landforms and deformation in the western part of the basin may be quite young. The easterly dipping normal fault set does not correspond with a regional dip toward the west and thus does not satisfy an hypothesis of gravitationnal reajustment or collapse. On the contrary, west of the normal fault set, some ongoing compressional forces are revealed by a large scale folding of the Central basin. These tectonic features led to some minor topographic variations that produced on the top of the basin surface local sedimentary traps, regressive erosion, catchments and extrado grabens that controlled the sediment facies and distribution pattern. Recent coarse-grained alluvial fans were deposited and stopped by

  1. Green Chile Pepper Harvest Mechanization

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pungent green chile (genus /Capsicum/, also spelled chili) is a large, fragile fruit growing on berry shrubs. Chile is harvested by hand to maximize yields and minimize fruit damage. Labor for hand harvesting chile is increasingly costly and difficult to obtain. Harvest mechanization is viewed as...

  2. [Hospital medicine in Chile].

    PubMed

    Eymin, Gonzalo; Jaffer, Amir K

    2013-03-01

    After 15 years of development of Hospital Medicine in Chile, there are several benefits of this discipline. Among others, a reduction in the length of hospital stay, readmissions, costs, and improved medical teaching of students, residents and fellows have been observed. However, in South América there are only isolated groups dedicated to Hospital Medicine in Chile, Argentina and Brazil, with a rather slow growth. The unjustified fear of competition from sub specialists, and the fee for service system of payment in our environment may be important factors to understand this phenomenon. The aging of the population makes imperative to improve the safety of our patients and to optimize processes and resources within the hospital, to avoid squandering healthcare resources. The following is a detailed and evidence-based article, on how hospital medicine might benefit both the public and prívate healthcare systems in Chile. PMID:23900327

  3. 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)

    NASA Astrophysics Data System (ADS)

    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

  4. Country Profiles, Chile.

    ERIC Educational Resources Information Center

    Goldsmith, Alfredo; And Others

    A profile of Chile is sketched in this paper. Emphasis is placed on the nature, scope, and accomplishments of population activities in the country. Topics and sub-topics include: location and description of the country; population (size, growth patterns, age structure, urban/rural distribution, ethnic and religious composition, migration,…

  5. [Availability of physicians and specialists in Chile].

    PubMed

    Guillou, Michèle; Carabantes C, Jorge; Bustos F, Verónica

    2011-05-01

    The availability and planning of Human Resources are important issues in many countries, as it is a key factor to cope with the critical challenges of Health Care Systems. In Chile, the Ministry of Health has undertaken several studies in order to improve knowledge about the medical workforce both in public and private sectors. The aim of this paper is to update and systematize the existing data on physicians and specialists availability in Chile. Several information sources were crossed to obtain new and more precise figures about this topic. According to the Internal Revenue System, 29.996 physicians practice medicine in the country, 43% of them hired in public services, part or full time. There is a high concentration of professionals in the central regions of Chile. Being the overall density of physicians of one per 559 inhabitants, the figures in the central region is one per 471 and one per more than 800 in the South and North. Between 2004 and 2008, the public sector increased its physician workforce by more than 80% in primary health care and more than 20% in the secondary and tertiary levels. This paper presents a method for a more rigorous identification of the categories of general practitioner and specialist respectively, and the results obtained from the databases used.

  6. [Availability of physicians and specialists in Chile].

    PubMed

    Guillou, Michèle; Carabantes C, Jorge; Bustos F, Verónica

    2011-05-01

    The availability and planning of Human Resources are important issues in many countries, as it is a key factor to cope with the critical challenges of Health Care Systems. In Chile, the Ministry of Health has undertaken several studies in order to improve knowledge about the medical workforce both in public and private sectors. The aim of this paper is to update and systematize the existing data on physicians and specialists availability in Chile. Several information sources were crossed to obtain new and more precise figures about this topic. According to the Internal Revenue System, 29.996 physicians practice medicine in the country, 43% of them hired in public services, part or full time. There is a high concentration of professionals in the central regions of Chile. Being the overall density of physicians of one per 559 inhabitants, the figures in the central region is one per 471 and one per more than 800 in the South and North. Between 2004 and 2008, the public sector increased its physician workforce by more than 80% in primary health care and more than 20% in the secondary and tertiary levels. This paper presents a method for a more rigorous identification of the categories of general practitioner and specialist respectively, and the results obtained from the databases used. PMID:22051705

  7. Late Paleozoic onset of subduction and exhumation at the western margin of Gondwana (Chilenia Terrane): Counterclockwise P-T paths and timing of metamorphism of deep-seated garnet-mica schist and amphibolite of Punta Sirena, Coastal Accretionary Complex, central Chile (34° S)

    NASA Astrophysics Data System (ADS)

    Hyppolito, T.; García-Casco, A.; Juliani, C.; Meira, V. T.; Hall, C.

    2014-10-01

    In this study, the Paleozoic albite-epidote-amphibolite occurring as meter-sized intercalations within garnet-mica schist at Punta Sirena beach (Pichilemu region, central Chile) is characterized for the first time. These rocks constitute an unusual exposure of subduction-related rocks within the Paleozoic Coastal Accretionary Complex of central Chile. Whereas high pressure (HP) greenschist and cofacial metasediments are the predominant rocks forming the regional metamorphic basement, the garnet-mica schist and amphibolite yield higher P-T conditions (albite-epidote amphibolite facies) and an older metamorphic age. Combining detailed mineral chemistry and textural information, P-T calculations and Ar-Ar ages, including previously published material from the Paleozoic Accretionary Complex of central Chile, we show that the garnet-mica schist and associated amphibolite (locally retrograded to greenschist) are vestiges of the earliest subducted material now forming exotic bodies within the younger HP units of the paleo-accretionary wedge. These rocks are interpreted as having been formed during the onset of subduction at the southwestern margin of Gondwana. However, we show that the garnet-mica schist formed at a slightly greater depth (ca. 40 km) than the amphibolite (ca. 30 km) along the same hot-subduction gradient developed during the onset of subduction. Both lithotypes reached their peak-P conditions at ca. 335-330 Ma and underwent near-isobaric cooling followed by cooling and decompression (i.e., counterclockwise P-T paths). The forced return flow of the garnet-mica schist from the subduction channel started at ca. 320 Ma and triggered the exhumation of fragments of shallower accreted oceanic crust (amphibolite). Cores of phengite (garnet-mica schist) and amphibole (amphibolite) grains have similar chemical compositions in both the S1 and S2 domains, indicating rotation of these grains during the transposition of the burial-related (prograde peak-T) foliation S1

  8. Styles of early diagenesis and the preservation potential of onshore tsunami deposits-A re-survey of Isla Mocha, Central Chile, 2 years after the February 27, 2010, Maule tsunami

    NASA Astrophysics Data System (ADS)

    Bahlburg, Heinrich; Spiske, Michaela

    2015-08-01

    The style of early diagenesis and preservation of onshore tsunami deposits are poorly constrained. Only tsunami surveys and subsequent re-surveys can fill this information gap. Here we present the results of a first re-survey in 2012 on Isla Mocha following the original survey in 2010 in the wake of the February 27, 2010, Maule earthquake and tsunami in central Chile. As a result of this tsunami, a large number of boulders consisting of clay-rich fine sandstones representing the Miocene age bedrock of the island had been transferred from the tidal to shallow subtidal zone onto the coastal plain. Coarse clastic sediment mixtures of pebbles, granules, and sand entrained at coastal plain terraces and transported up to the maximum runup position c. 600 m from the coast by the inflow had been left behind as extensive backflow blankets on the lower coastal plain. In 2012, vegetation had covered the 2010 tsunami deposits. Sediment beyond 200 m from the coast had been removed by a combination of surface processes and grazing cattle. Grain-size distributions of the preserved sediment show an increase of the sand fraction at the expense of the coarser grain sizes. Boulders show patterns resembling mud cracks on the surface and evidence of disintegration into smaller fragments and sand. Veneers of dried algae documenting the derivation of the boulders from the tidal zones had flaked off partly or completely from most rock surfaces. At the northern, wind-facing coast of the island, a c. 130 m long and 1.2 m high beach ridge had accumulated, most likely from reworked tsunami sediment. Boulders deposited by tsunamis are commonly assigned a high preservation potential. We demonstrate for the first time that such boulders may in fact disintegrate rapidly and disappear from the record over short geological time scales, given a lithology susceptible to weathering. The degree of modification to the lsla Mocha tsunami boulders and deposits strongly questions the applicability of

  9. 2010 Chile Earthquake Aftershock Response

    NASA Astrophysics Data System (ADS)

    Barientos, Sergio

    2010-05-01

    The Mw=8.8 earthquake off the coast of Chile on 27 February 2010 is the 5th largest megathrust earthquake ever to be recorded and provides an unprecedented opportunity to advance our understanding of megathrust earthquakes and associated phenomena. The 2010 Chile earthquake ruptured the Concepcion-Constitucion segment of the Nazca/South America plate boundary, south of the Central Chile region and triggered a tsunami along the coast. Following the 2010 earthquake, a very energetic aftershock sequence is being observed in an area that is 600 km along strike from Valparaiso to 150 km south of Concepcion. Within the first three weeks there were over 260 aftershocks with magnitude 5.0 or greater and 18 with magnitude 6.0 or greater (NEIC, USGS). The Concepcion-Constitucion segment lies immediately north of the rupture zone associated with the great magnitude 9.5 Chile earthquake, and south of the 1906 and the 1985 Valparaiso earthquakes. The last great subduction earthquake in the region dates back to the February 1835 event described by Darwin (1871). Since 1835, part of the region was affected in the north by the Talca earthquake in December 1928, interpreted as a shallow dipping thrust event, and by the Chillan earthquake (Mw 7.9, January 1939), a slab-pull intermediate depth earthquake. For the last 30 years, geodetic studies in this area were consistent with a fully coupled elastic loading of the subduction interface at depth; this led to identify the area as a mature seismic gap with potential for an earthquake of magnitude of the order 8.5 or several earthquakes of lesser magnitude. What was less expected was the partial rupturing of the 1985 segment toward north. Today, the 2010 earthquake raises some disturbing questions: Why and how the rupture terminated where it did at the northern end? How did the 2010 earthquake load the adjacent segment to the north and did the 1985 earthquake only partially ruptured the plate interface leaving loaded asperities since

  10. Evolution of the late Paleozoic accretionary complex and overlying forearc-magmatic arc, south central Chile (38°-41°S): Constraints for the tectonic setting along the southwestern margin of Gondwana

    NASA Astrophysics Data System (ADS)

    Martin, Mark W.; Kato, Terence T.; Rodriguez, Carolina; Godoy, Estanislao; Duhart, Paul; McDonough, Michael; Campos, Alberto

    1999-08-01

    Stratigraphic, structural, metamorphic, and geochronologic studies of basement rocks in the Andean foothills and Coast Ranges of south central Chile (39°-41°S) suggest a protracted late Paleozoic to middle Mesozoic deformational and metamorphic history that imposes important constraints on the tectonic development of the southwestern Gondwana margin. In the study area the late Paleozoic paired metamorphic belt, coeval magmatic arc, and overlying Triassic sedimentary units preserve a record of Late Carboniferous to Early Permian subduction and arc magmatism, subsequent deep exhumation of the Western Series subduction complex, and diminished uplift and erosion of the Eastern Series arc-forearc region by the Late Triassic. Late Paleozoic structural elements and metamorphic assemblages formed during early subduction and arc magmatism, collectively referred to as Dl, are largely erased in the Western Series by the dominant D2 schistosity and lower greenschist grade metamorphism. D1 structural features, as well as original sedimentary textures, are relatively well preserved in the less penetratively deformed Eastern Series. The regional distribution of late Paleozoic arc magmatism suggests that the late Paleozoic convergent margin deviated from a N-S trend north of this area to a NW-SE trend near this latitude and faced an open marine environment to the southwest. A transition from F2 isoclinal folding to more open, larger-scale F3 folds, interpreted as change in ductility during differential uplift of the Western Series, is not apparent in the Eastern Series. Despite a lesser degree of uplift during the main exhumational D2 event, delineation of unconformities and U-Pb dating of detrital zircons and intrusions into the Eastern Series allow tighter constraints to be placed on timing of uplift and denudation of the Eastern Series than on that in the Western Series. A regional unconformity exposed in the Lake District that separates more highly deformed Eastern Series

  11. Subduction of the South-Chile active spreading ridge: a 17 Ma to 3 Ma magmatic record in central Patagonia (western edge of Meseta del Lago Buenos Aires, Argentina)

    NASA Astrophysics Data System (ADS)

    Boutonnet, Emmanuelle; Arnaud, Nicolas; Guivel, Christèle; Lagabrielle, Yves; Scalabrino, Bruno; Espinoza, Felipe

    2010-05-01

    The Chile Triple Junction is a natural laboratory to study the interactions between magmatism and tectonics during the subduction of an active spreading ridge beneath a continent. The MLBA plateau (Meseta del Lago Buenos Aires) is one of the Neogene alkali basaltic plateaus located in the back-arc region of the Andean Cordillera at the latitude of the current Chile Triple Junction. The genesis of MLBA can be related with successive opening of slabs windows beneath Patagonia: within the subducting Nazca Plate itself and between the Nazca and Antarctic plates. Detailed 40Ar/39Ar dating and geochemical analysis of bimodal magmatism from the western flank of the MLBA show major changes in the back-arc magmatism which occurred between 14.5 Ma and 12.5 Ma with the transition from calc-alkaline lavas (Cerro Plomo) to alkaline lavas (MLBA) in relation with slab window opening. In a second step, at 4- 3 Ma, alkaline felsic intrusions were emplaced in the western flank of the MLBA coevally with the MLBA basalts with which they are genetically related. These late OIB-like alkaline to transitional basalts were generated by partial melting of the subslab asthenosphere of the subducting Nazca plate during the opening of the South Chile spreading ridge-related slab window. These basalts differentiated with small amounts of assimilation in shallow magma chambers emplaced along transtensional to extensional zones. The close association of bimodal magmatism with extensional tectonic features in the western MLBA is a strong support to the model of Patagonian collapse event proposed to have taken place between 5 and 3 Ma as a consequence of the presence of the asthenospheric window (SCR-1 segment of South Chile Ridge) below the MLBA area.

  12. Chile rural electrification cooperation

    SciTech Connect

    Flowers, L.

    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.

  13. [Erysipelas outbreaks in Chile].

    PubMed

    Laval R, Enrique

    2011-04-01

    Historical antecedents of erysipelas outbreaks in Chile, registered by national bibliography at years 1822 and 1873 are reviewed. The first one, after an earthquake, with numerous severe ataxo-adynamic manifestations and the second, more attenuated with few severe cases. Remembers of treatments utilized at XIX Century for the disease and the beginning of sulphamides prescription at the thirty decade are presented. Afterwards penicillin and other antimicrobial agents treatments were implemented. Finally, we comment the severe presentation of soft tissues streptococcal diseases that appeared in the end of XX Century.

  14. Fires in Chile

    NASA Technical Reports Server (NTRS)

    2002-01-01

    On February 5, 2002, the dense smoke from numerous forest fires stretched out over the Pacific Ocean about 400 miles south of Santiago, Chile. This true-color Moderate-resolution Imaging Spectroradiometer (MODIS) image shows the fires, which are located near the city of Temuco. The fires are indicated with red dots (boxes in the high-resolution imagery). The fires were burning near several national parks and nature reserves in an area of the Chilean Andes where tourism is very popular. Southeast of the fires, the vegetation along the banks of the Rio Negro in Argentina stands out in dark green. Image courtesy Jacques Descloitres, MODIS Land Rapid Response Team at NASA GSFC

  15. Eso's Situation in Chile

    NASA Astrophysics Data System (ADS)

    1995-02-01

    ESO, the European Southern Observatory, in reply to questions raised by the international media, as well as an ongoing debate about the so-called "Paranal case" in Chilean newspapers, would like to make a number of related observations concerning its status and continued operation in that country [1]. THE ESO OBSERVATORY SITES IN CHILE The European Southern Observatory, an international organisation established and supported by eight European countries, has been operating more than 30 years in the Republic of Chile. Here ESO maintains one of the world's prime astronomical observatories on the La Silla mountain in the southern part of the Atacama desert. This location is in the Fourth Chilean Region, some 600 km north of Santiago de Chile. In order to protect the La Silla site against dust and light pollution from possible future mining industries, roads and settlements, ESO early acquired the territory around this site. It totals about 825 sq. km and has effectively contributed to the preservation of its continued, excellent "astronomical" quality. Each year, more than 500 astronomers from European countries, Chile and elsewhere profit from this when they come to La Silla to observe with one or more of the 15 telescopes now located there. In 1987, the ESO Council [2] decided to embark upon one of the most prestigious and technologically advanced projects ever conceived in astronomy, the Very Large Telescope (VLT). It will consist of four interconnected 8.2-metre telescopes and will become the largest optical telescope in the world when it is ready. It is safe to predict that many exciting discoveries will be made with this instrument, and it will undoubtedly play a very important role in our exploration of the distant universe and its many mysteries during the coming decades. THE VLT AND PARANAL In order to find the best site for the VLT, ESO performed a thorough investigation of many possible mountain tops, both near La Silla and in Northern Chile. They showed

  16. Rapid Characterization of Large Earthquakes in Chile

    NASA Astrophysics Data System (ADS)

    Barrientos, S. E.; Team, C.

    2015-12-01

    Chile, along 3000 km of it 4200 km long coast, is regularly affected by very large earthquakes (up to magnitude 9.5) resulting from the convergence and subduction of the Nazca plate beneath the South American plate. These megathrust earthquakes exhibit long rupture regions reaching several hundreds of km with fault displacements of several tens of meters. Minimum delay characterization of these giant events to establish their rupture extent and slip distribution is of the utmost importance for rapid estimations of the shaking area and their corresponding tsunami-genic potential evaluation, particularly when there are only few minutes to warn the coastal population for immediate actions. The task of a rapid evaluation of large earthquakes is accomplished in Chile through a network of sensors being implemented by the National Seismological Center of the University of Chile. The network is mainly composed approximately by one hundred broad-band and strong motion instruments and 130 GNSS devices; all will be connected in real time. Forty units present an optional RTX capability, where satellite orbits and clock corrections are sent to the field device producing a 1-Hz stream at 4-cm level. Tests are being conducted to stream the real-time raw data to be later processed at the central facility. Hypocentral locations and magnitudes are estimated after few minutes by automatic processing software based on wave arrival; for magnitudes less than 7.0 the rapid estimation works within acceptable bounds. For larger events, we are currently developing automatic detectors and amplitude estimators of displacement coming out from the real time GNSS streams. This software has been tested for several cases showing that, for plate interface events, the minimum magnitude threshold detectability reaches values within 6.2 and 6.5 (1-2 cm coastal displacement), providing an excellent tool for earthquake early characterization from a tsunamigenic perspective.

  17. Escondida Mine, Chile

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Full resolution visible and near-infrared image (1.4 MB) Full resolution shortwave infrared image (1.6 MB) This Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) image covers 30 by 23 km (full images 30 x 37 km) in the Atacama Desert, Chile, and was acquired on April 23, 2000. The Escondida copper, gold, and silver open-pit mine is at an elevation of 3050 m, and began operations in 1990. Current capacity is 127,000 tons/day of ore; in 1999 production totaled 827,000 tons of copper, 150,000 ounces of gold, and 3.53 million ounces of silver. Primary concentrate of the ore is done on-site; the concentrate is then sent to the coast for further processing through a 170 km long, 9-inch pipe. Escondida is related geologically to three porphyry bodies intruded along the Chilean West Fissure Fault System. A high grade supergene cap overlies primary sulfide ore. The top image is a conventional 3-2-1 (near infrared, red, green) RGB composite. The bottom image displays shortwave infrared bands 4-6-8 (1.65um, 2.205um, 2.33um) in RGB, and highlights the different rock types present on the surface, as well as the changes caused by mining. Image courtesy NASA/GSFC/MITI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team

  18. Country watch: Chile.

    PubMed

    Montoya Leiva, M

    1996-01-01

    Servicio Paz y Justicia (SERPAJ) is a nongovernmental organization (NGO) established in Chile in 1977. It supports fundamental human dignity and rights by fighting discrimination and exclusion based upon individual differences. SERPAJ promotes training, organization, and the political participation of community members as part of the democratic process, working mainly with the at risk women, street children, and youth of Santiago's working-class neighborhoods. Groups participate in workshops and training courses on human rights and development, civic education, and methods of non-violent community action. In 1987, SERPAJ-Sur Oriente began to include the topic of sexuality and AIDS/STDs in courses training working-class women as community human rights agents. The NGO is therefore one of the first mainstream Chilean human rights organizations to incorporate HIV/AIDS issues. A basic facts brochure was developed, followed by a pilot education project developed in one neighborhood which was then systematically replicated in other neighborhoods. The comments of some people who have participated in SERPAJ workshops are presented.

  19. Escondida Mine, Chile

    NASA Technical Reports Server (NTRS)

    2001-01-01

    [figure removed for brevity, see original site] Figure 1 Click on image for larger version

    This ASTER image covers 30 by 37 km in the Atacama Desert, Chile and was acquired on April 23, 2000. The Escondida Cu-Au-Ag open-pit mine is at an elevation of 3050 m, and came on stream in 1990. Current capacity is 127,000 tons/day of ore; in 1999 production totaled 827,000 tons of copper, 150,000 ounces of gold and 3.53 million ounces of silver. Primary concentration of the ore is done on-site; the concentrate is then sent to the coast for further processing through a 170 km long, 9 pipe. Escondida is related geologically to three porphyry bodies intruded along the Chilean West Fissure Fault System. A high grade supergene cap overlies primary sulfide ore. This image is a conventional 3-2-1 RGB composite. Figure 1 displays SWIR bands 4-6-8 in RGB, and highlights lithologic and alteration differences of surface units. The image is located at 24.3 degrees south latitude and 69.1 degrees west longitude.

    The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

  20. [Chile: Standing up again].

    PubMed

    Reyes B, Humberto

    2010-03-01

    One of the biggest earthquakes recorded in human history has recently devastated a large part of the Chilean territory and, followed by a Tsunami, destroyed cities, seaports, fishermen's coves, bridges, and countryside houses. This cataclysm affected a large proportion of our population, leaving homeless families, no working tools for work places, hospitals, schools, public buildings, museums. However, the loss of human Uves was small compared to similar disasters. It destroyed part of the national heritage as well as damaged people's living conditions. A national movement started immediately to help and recover, and international resources, both human and technological were also set in motion. As after previous earthquakes in Chile, young M.D.'s and medical students were organized in voluntary groups backed by institutions or by their own organizations and went from large cities as Santiago and others to provide medical and psychological care to those in most need. Young members and students of other health professions (nurses, physical therapists, etc.) were included in these groups or worked in their own ones. National and international experience indicates that the forthcoming months require special care of psychological reactions and sequel (posttraumatic stress symptoms) and health consequences after water pollution, restrictions in housing and deteriorated sanitary conditions. Nevertheless, our country will stand up once more.

  1. Country watch: Chile.

    PubMed

    Montoya Leiva, M

    1996-01-01

    Servicio Paz y Justicia (SERPAJ) is a nongovernmental organization (NGO) established in Chile in 1977. It supports fundamental human dignity and rights by fighting discrimination and exclusion based upon individual differences. SERPAJ promotes training, organization, and the political participation of community members as part of the democratic process, working mainly with the at risk women, street children, and youth of Santiago's working-class neighborhoods. Groups participate in workshops and training courses on human rights and development, civic education, and methods of non-violent community action. In 1987, SERPAJ-Sur Oriente began to include the topic of sexuality and AIDS/STDs in courses training working-class women as community human rights agents. The NGO is therefore one of the first mainstream Chilean human rights organizations to incorporate HIV/AIDS issues. A basic facts brochure was developed, followed by a pilot education project developed in one neighborhood which was then systematically replicated in other neighborhoods. The comments of some people who have participated in SERPAJ workshops are presented. PMID:12347181

  2. Different Seed Selection and Conservation Practices for Fresh Market and Dried Chile Farmers in Aguascalientes, Mexico

    PubMed Central

    de Jesús Luna-Ruíz, José; Gepts, Paul

    2010-01-01

    Different Seed Selection and Conservation Practices for Fresh Market and Dried Chile Farmers in Aguascalientes, Mexico. The process of selecting and saving seed is the most basic and oldest of agricultural practices. In today’s modern and highly capital-intensive agriculture, seeds are often treated like another chemical input. This study sought to examine seed selection and saving practices among chile farmers in Aguascalientes, Mexico, where both industrial and traditional agriculture are practiced. We observed a clear division among farmers who plant chile peppers commercially. Sixty-eight chile pepper farmers were surveyed in order to document seed selection and saving practices. Fifteen respondents (22%) planted chile peppers destined for the fresh market and all utilized purchased commercial seed of F1 hybrid varieties. Fifty-three farmers (78%) planted chiles to be dried and either saved their own or purchased seeds that others had saved and selected. Farmers who saved their own seed sought to maintain an ideotype, rather than directionally select for certain traits, much like Cleveland et al. (2000) chronicled in central Mexican maize farmers. Farmers would benefit from a participatory plant-breeding program in order to maintain productive seed stock for the continued cultivation of dried chile pepper in the state. PMID:21212817

  3. [New medical schools in Chile].

    PubMed

    Castillo, P

    1994-03-01

    In Chile there are six established medical schools at public (Chile, Valparaiso and Temuco) or private (Catholic, Concepción and Austral) universities created between 1833 and 1971. Since 1990, three new medical schools (two private) were created and a fourth is projected, concerning the chilean medical corps. We present three position articles on the subject written by Dean Pedro Rosso, from the Catholic University, Dr Pedro Castillo, Chief of Human Resources of the Ministry of Health and Dean Alejandro Goic from the University of Chile. Dean Rosso emphasizes the need to have assessment procedures that guarantee quality standards in the new medical schools. Dr Castillo attracts attention on preserving the compromise with the society, inherent to chilean medicine. Dean Goic analyzes systematically the reasons to prevent the proliferation of medical schools in the country, maintaining an equilibrium between freedom of teaching and public faith protection.

  4. [New medical schools in Chile].

    PubMed

    Castillo, P

    1994-03-01

    In Chile there are six established medical schools at public (Chile, Valparaiso and Temuco) or private (Catholic, Concepción and Austral) universities created between 1833 and 1971. Since 1990, three new medical schools (two private) were created and a fourth is projected, concerning the chilean medical corps. We present three position articles on the subject written by Dean Pedro Rosso, from the Catholic University, Dr Pedro Castillo, Chief of Human Resources of the Ministry of Health and Dean Alejandro Goic from the University of Chile. Dean Rosso emphasizes the need to have assessment procedures that guarantee quality standards in the new medical schools. Dr Castillo attracts attention on preserving the compromise with the society, inherent to chilean medicine. Dean Goic analyzes systematically the reasons to prevent the proliferation of medical schools in the country, maintaining an equilibrium between freedom of teaching and public faith protection. PMID:7809525

  5. [Genetic evidence corroborates Negme's hypothesis about the greater mildness of American trypanosomiasis in Chile].

    PubMed

    Acuña, M; Rothhammer, F; Moreno, R; Barton, S; Arribada, A; Apt, W; Llop, E

    1992-03-01

    Chagas disease is present in northern and central Chile. Not more than 25% of infected individuals have had a pathologic condition presumably due to Trypanosoma cruzi. The majority of individuals with chronic infectious Chagas disease in Chile are asymptomatic in contrast to what has been observed in other South American countries. Historic and paleopathologic evidences suggest that this particular behavior could be explained by a genetic adaptation of Chilean aborigines to T cruzi. Associations between ethnic admixture, presence of Chagas disease, associated cardiac pathology and 4 blood groups (ABO, MNSs, Rh and Duffy) were investigated among inhabitants of San Pedro de Atacama in northern Chile. Cardiac pathology was determined by positive serologic reactions in individuals with abnormal electrocardiographic findings. Individuals with negative serologic results had a significantly greater aboriginal admixture (88%) compared to those with positive serology (66%). This findings supports the hypothesis of genetic adaptation explaining mildness of Chagas disease in Chile.

  6. Patagonia Glacier, Chile

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This ASTER images was acquired on May 2, 2000 over the North Patagonia Ice Sheet, Chile near latitude 47 degrees south, longitude 73 degrees west. The image covers 36 x 30 km. The false color composite displays vegetation in red. The image dramatically shows a single large glacier, covered with crevasses. A semi-circular terminal moraine indicates that the glacier was once more extensive than at present. ASTER data are being acquired over hundreds of glaciers worldwide to measure their changes over time. Since glaciers are sensitive indicators of warming or cooling, this program can provide global data set critical to understand climate change.

    This image is located at 46.5 degrees south latitude and 73.9 degrees west longitude.

    Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of International Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. Dr. Anne Kahle at NASA's Jet Propulsion Laboratory, Pasadena, Calif., is the U.S. Science team leader; Moshe Pniel of JPL is the project manager. ASTER is the only high resolution imaging sensor on Terra. The primary goal of the ASTER mission is to obtain high-resolution image data in 14 channels over the entire land surface, as well as black and white stereo images. With revisit time of between 4 and 16 days, ASTER will provide the capability for repeat coverage of changing areas on Earth's surface.

    The broad spectral coverage and high spectral resolution of ASTER will provide scientists in numerous disciplines with critical information for surface mapping, and monitoring dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats, monitoring potentially active volcanoes, identifying crop stress, determining cloud

  7. Women and Politics in Chile.

    ERIC Educational Resources Information Center

    Kirkwood, Julieta

    1983-01-01

    Political parties in Chile of both the left and right have focused more on drawing women into their ideologies than on considering what political issues mean to women. A look at feminist thought shows how political life for women includes not only the traditional political arena but also domestic life. (IS)

  8. Chiliques volcano, Chile

    NASA Technical Reports Server (NTRS)

    2002-01-01

    A January 6, 2002 ASTER nighttime thermal infrared image of Chiliques volcano in Chile shows a hot spot in the summit crater and several others along the upper flanks of the edifice, indicating new volcanic activity. Examination of an earlier nighttime thermal infrared image from May 24,2000 showed no thermal anomaly. Chiliques volcano was previously thought to be dormant. Rising to an elevation of 5778 m, Chiliques is a simple stratovolcano with a 500-m-diameter circular summit crater. This mountain is one of the most important high altitude ceremonial centers of the Incas. It is rarely visited due to its difficult accessibility. Climbing to the summit along Inca trails, numerous ruins are encountered; at the summit there are a series of constructions used for rituals. There is a beautiful lagoon in the crater that is almost always frozen.

    The daytime image was acquired on November 19, 2000 and was created by displaying ASTER bands 1,2 and 3 in blue, green and red. The nighttime image was acquired January 6, 2002, and is a color-coded display of a single thermal infrared band. The hottest areas are white, and colder areas are darker shades of red. Both images cover an area of 7.5 x 7.5 km, and are centered at 23.6 degrees south latitude, 67.6 degrees west longitude.

    Both images cover an area of 7.5 x 7.5 km, and are centered at 23.6 degrees south latitude, 67.6 degrees west longitude.

    These images were acquired by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite. With its 14spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER will image Earth for the next 6 years to map and monitor the changing surface of our planet.

    ASTER is one of five Earth-observing instruments launched December 18,1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A

  9. Variability of 14C reservoir age and air-sea flux of CO2 in the Peru-Chile upwelling region during the past 12,000 years

    NASA Astrophysics Data System (ADS)

    Carré, Matthieu; Jackson, Donald; Maldonado, Antonio; Chase, Brian M.; Sachs, Julian P.

    2016-01-01

    The variability of radiocarbon marine reservoir age through time and space limits the accuracy of chronologies in marine paleo-environmental archives. We report here new radiocarbon reservoir ages (ΔR) from the central coast of Chile (~ 32°S) for the Holocene period and compare these values to existing reservoir age reconstructions from southern Peru and northern Chile. Late Holocene ΔR values show little variability from central Chile to Peru. Prior to 6000 cal yr BP, however, ΔR values were markedly increased in southern Peru and northern Chile, while similar or slightly lower-than-modern ΔR values were observed in central Chile. This extended dataset suggests that the early Holocene was characterized by a substantial increase in the latitudinal gradient of marine reservoir age between central and northern Chile. This change in the marine reservoir ages indicates that the early Holocene air-sea flux of CO2 could have been up to five times more intense than in the late Holocene in the Peruvian upwelling, while slightly reduced in central Chile. Our results show that oceanic circulation changes in the Humboldt system during the Holocene have substantially modified the air-sea carbon flux in this region.

  10. Is Chile Complying with its Light Pollution Regulations? A Status Report

    NASA Astrophysics Data System (ADS)

    Smith, M. G.; Sanhueza, P.; Schwarz, H. E.; Walker, A. R.

    2005-12-01

    Monte Patria is the first Municipality in Chile to comply fully with Supreme Decree 686, the Chilean, environmentally-based legislation governing exterior lighting in Northern Chile - the "norma luminica". "Before" and "after" photographs of Monte Patria were published in last June's issue of "Physics Today", in the context of the global effort to control light pollution. Some photographs of other Chilean towns have been obtained for this poster and for display at the International Dark Sky Association's stand at this meeting. Highlights include detailed midnight and dawn panoramas taken by us during October, 2005 - the month in which the six-year "grace period" for all external lighting in northern Chile's astronomically-sensitive 2nd, 3rd and 4th Regions was supposed to come into full compliance. It is clear that significant progress is being made. The chief obstacle has been financial. Large-scale changeout of street lighting requires an outlay of many millions of dollars from cash-strapped municipalities. Chile's central government has moved in to provide financing at the 80-100/% level in many cases. Once Chile's congressional elections are over, we will be able to judge the political will to complete the changeover. Various large mining operations are currently engaged in major lighting changeovers; such changes are especially important in the various mines that are directly visible from existing major observatories in Northern Chile. The importance to astronomy is that full compliance with DS686 will, on average, extend the potential useful life of all the major optical observatories in Northern Chile by several decades. Funding for the Office for the Protection of the Quality of the Skies of Chile (OPCC) is provided by the Chilean National Environment Committee (CONAMA), NOAO, Gemini, ESO and the Las Campanas Observatory of the Carnegie Institute of Washington.

  11. [Chile: social protection in health].

    PubMed

    Urriola, Rafael

    2006-10-01

    This piece begins with a brief discussion of the concepts leading to the social right to health protection. Special emphasis is placed on the principle of social cohesion, which has influenced social health protection in European countries. Chile's experience in this field from the 1990s to the present is described, as exemplified in three dimensions. In the first place, social security coverage is presented as a means to achieve universal (horizontal) coverage. A discussion follows on vertical coverage, where the author identifies health problems for which insured persons have guaranteed rights of access to medical care. This section describes available emergency care, primary health care, and the special plan for Universal Access to Explicit Guarantees (Acceso Universal de Garantías Explícitas de salud, or AUGE). Thirdly, the discussion covers the funding sources supporting the Chilean health care system: Government subsidies, contributions to social security, and out-of-pocket disbursements for private care. Chile's public health system has various special programs. One of them is catastrophic insurance, which covers 100% of the care needed for complex and very costly treatments. Older persons (over 65) have coverage for 100% of the cost of eyeglasses and hearing aids, and for 50% of the cost of home care. If life expectancy is an appropriate indicator of health system results, it is worth noting that Chile and the United States of America have both achieved a life expectancy of 77 years, even though Chile spends only 5.9% of its gross domestic product on health care, as compared to the 15% spent by the United States.

  12. Canl to Curarrehue (Chile): A Journey in Alternative Development. Outdoor Education and Sustainable Development: Part Two.

    ERIC Educational Resources Information Center

    Walker, Rod

    1999-01-01

    The outdoor experience's core element of connection to the earth is a central feature of an environmental-education project in Canl forest sanctuary (Chile). Developed to provide integrated environmental and adventure-education experiences to forest visitors, the project expanded to train local youth as ecotourism guides and native-tree nursery…

  13. Constraints on the development of orogenic style gold mineralisation at Mineral de Talca, Coastal Range, central Chile: evidence from a combined structural, mineralogical, S and Pb isotope and geochronological study

    NASA Astrophysics Data System (ADS)

    Firth, Emily A.; Holwell, David A.; Oliver, Nicholas H. S.; Mortensen, James K.; Rovardi, Matthew P.; Boyce, Adrian J.

    2015-08-01

    Mineral de Talca is a rare occurrence of Mesozoic, gold-bearing quartz vein mineralisation situated within the Coastal Range of northern Chile. Quartz veins controlled by NNW-SSE-trending faults are hosted by Devonian-Carboniferous metasediments of greenschist facies and younger, undeformed granitoid and gabbro intrusions. The principal structural control in the area is the easterly dipping, NNW-SSE-trending El Teniente Fault, which most likely developed as an extensional normal fault in the Triassic but was later reactivated as a strike-slip fault during subsequent compression. A dilational zone in the El Teniente Fault appears to have focussed fluid flow, and an array of NW-SE-trending veins is present as splays off the El Teniente Fault. Mineralised quartz veins typically up to a metre thick occur in three main orientations: (1) parallel to and within NNW-SSE-trending, E-dipping faults throughout the area; (2) along NW-SE-trending, NE-dipping structures which may also host andesite dykes; and (3) rarer E-W-trending, subvertical veins. All mineralised quartz veins show evidence of multiple fluid events with anastomosing and crosscutting veins and veinlets, some of which contain up to 3.5 vol.% base metal sulphides. Mineralogically, Au is present in three textural occurrences, identified by 3D CT scanning: (1) with arsenopyrite and pyrite in altered wall rock and along the margins of some of the veins; (2) with Cu-Pb-Zn sulphides within quartz veins; and (3) as nuggets and clusters of native Au within quartz. Fluid inclusion work indicates the presence of CO2-CH4-bearing fluids with homogenisation temperatures of ˜350 °C and aqueous fluids with low-moderate salinities (0.4-15.5 wt% NaCl eq.) with homogenisation temperatures in the range of 161-321 °C. The presence of Au with arsenopyrite and pyrite in structurally controlled quartz veins and in greenschist facies rocks with evidence of CO2-bearing fluids is consistent with an orogenic style classification for

  14. Field survey of the 16 September 2015 Chile tsunami

    NASA Astrophysics Data System (ADS)

    Lagos, Marcelo; Fritz, Hermann M.

    2016-04-01

    On the evening of 16 September, 2015 a magnitude Mw 8.3 earthquake occurred off the coast of central Chile's Coquimbo region. The ensuing tsunami caused significant inundation and damage in the Coquimbo or 4th region and mostly minor effects in neighbouring 3rd and 5th regions. Fortunately, ancestral knowledge from the past 1922 and 1943 tsunamis in the region along with the catastrophic 2010 Maule and recent 2014 tsunamis, as well as tsunami education and evacuation exercises prompted most coastal residents to spontaneously evacuate to high ground after the earthquake. There were a few tsunami victims; while a handful of fatalities were associated to earthquake induced building collapses and the physical stress of tsunami evacuation. The international scientist joined the local effort from September 20 to 26, 2015. The international tsunami survey team (ITST) interviewed numerous eyewitnesses and documented flow depths, runup heights, inundation distances, sediment deposition, damage patterns, performance of the navigation infrastructure and impact on the natural environment. The ITST covered a 500 km stretch of coastline from Caleta Chañaral de Aceituno (28.8° S) south of Huasco down to Llolleo near San Antonio (33.6° S). We surveyed more than 40 locations and recorded more than 100 tsunami and runup heights with differential GPS and integrated laser range finders. The tsunami impact peaked at Caleta Totoral near Punta Aldea with both tsunami and runup heights exceeding 10 m as surveyed on September 22 and broadcasted nationwide that evening. Runup exceeded 10 m at a second uninhabited location some 15 km south of Caleta Totoral. A significant variation in tsunami impact was observed along the coastlines of central Chile at local and regional scales. The tsunami occurred in the evening hours limiting the availability of eyewitness video footages. Observations from the 2015 Chile tsunami are compared against the 1922, 1943, 2010 and 2014 Chile tsunamis. The

  15. Rising Expectations in Brazil and Chile

    ERIC Educational Resources Information Center

    Elacqua, Gregory; Alves, Fatima

    2014-01-01

    Two themes connect Brazil and Chile: one is economic success; the other is social unrest. Protests rocked cities across Brazil in June 2013, and in Chile, recent student protests turned violent. Yet living conditions in both nations are better now than they've ever been. Successful economic and social reforms over the last two decades have…

  16. [Antimicrobial susceptibility in Chile 2012].

    PubMed

    Cifuentes-D, Marcela; Silva, Francisco; García, Patricia; Bello, Helia; Briceño, Isabel; Calvo-A, Mario; Labarca, Jaime

    2014-04-01

    Bacteria antimicrobial resistance is an uncontrolled public health problem that progressively increases its magnitude and complexity. The Grupo Colaborativo de Resistencia, formed by a join of experts that represent 39 Chilean health institutions has been concerned with bacteria antimicrobial susceptibility in our country since 2008. In this document we present in vitro bacterial susceptibility accumulated during year 2012 belonging to 28 national health institutions that represent about 36% of hospital discharges in Chile. We consider of major importance to report periodically bacteria susceptibility so to keep the medical community updated to achieve target the empirical antimicrobial therapies and the control measures and prevention of the dissemination of multiresistant strains.

  17. ALMA communication backbone in Chile goes optical

    NASA Astrophysics Data System (ADS)

    Filippi, G.; Ibsen, J.; Jaque, Sandra; Liello, F.; Navarro, C.

    2014-07-01

    High-bandwidth communication has become a key factor for scientific installations as Observatories. This paper describes the technical, organizational, and operational goals and the level of completion of the ALMA Optical Link Project. The project focus is the creation and operation of an effective and sustainable communication infrastructure to connect the ALMA Observatory, located in the Atacama Desert, in the Northern region of Chile, with the point of presence in ANTOFAGASTA, about 400km away, of the EVALSO infrastructure, and from there to the Central Office in the Chilean capital, Santiago. This new infrastructure that will be operated in behalf of ALMA by REUNA, the Chilean National Research and Education Network, will use state of the art technologies, like dark fiber from newly built cables and DWDM transmission, allowing extending the reach of high capacity communication to the remote region where the Observatory is located. When completed, the end-to-end Gigabit-per-second (Gbps) capable link will provide ALMA with a modern, effective, robust, communication infrastructure capable to cope with present and future demands, like those coming from fast growing data transfer to rapid response mode, from remote monitoring and engineering to virtual presence.

  18. Sedimentological processes in a scarp-controlled rocky shoreline to upper continental slope environment, as revealed by unusual sedimentary features in the Neogene Coquimbo Formation, north-central Chile

    NASA Astrophysics Data System (ADS)

    Le Roux, J. P.; Gómez, Carolina; Fenner, Juliane; Middleton, Heather

    2004-03-01

    Exceptionally good outcrops of Miocene to Pliocene deposits in the vicinity of submarine Paleozoic basement scarps at Carrizalillo, north of La Serena, reveal a wealth of sedimentary features not commonly observed. The most proximal facies consist of rock fall and coarse-grained debris flow deposits directly abutting the basement wall from which they originated. Angular basement clasts are mixed with well-rounded cobbles, which probably formed as a basal gravel on a wave-cut platform at the beginning of marine flooding, subsequently accumulated at the scarp edge and were incorporated into the debris when the latter collapsed. The poor sorting, inverse grading, and protruding cobbles and boulders are classical debris flow features, with good clast imbrication indicating a laminar shearing action. A medial facies is represented by secondary channels running parallel to the major scarp about 1 km downslope of the first locality. In the largest channel, megaflutes at the base indicate the passage of highly turbulent, nondepositing flows eroding the soft, silty substrate. In the deepest, central part of the channel, a pebbly coquina shows horizontal and trough cross-stratification, with most of the bivalves oriented convex side up. Meter-scale rip-up clasts of the underlying siltstone are also present, indicating turbulent flow with a density sufficiently high to retard settling. The coquina is interpreted as a detachment deposit resulting from a hydroplaning debris flow along the central part of the channel, where the velocity and rate of pore pressure decay were highest. This deposit is overlain by fining upward, massive to horizontally stratified sandstone very similar in texture and composition to the matrix of the debris flow, suggesting its formation by surface transformation and elutriation of the latter. Along the channel margin, a basal centimeter-scale sandstone layer is virtually unaffected by the megaflute topography and clearly represents a subsequent event

  19. Teacher-child interactions in Chile and their associations with prekindergarten outcomes.

    PubMed

    Leyva, Diana; Weiland, Christina; Barata, M; Yoshikawa, Hirokazu; Snow, Catherine; Treviño, Ernesto; Rolla, Andrea

    2015-01-01

    Quality of teacher-child interactions is central to prekindergarten children's learning. In the United States, the quality of teacher-child interactions is commonly assessed using the teaching through interactions conceptual framework and an associ/ated observational tool, the Classroom Assessment Scoring System (CLASS). This study examined: (a) whether there was evidence supporting three distinctive domains of teacher-child interactions in Chile (construct validity) and (b) whether these domains predicted end-of-prekindergarten language, academic, and executive function skills in Chile (predictive validity). The sample consisted of 91 Chilean prekindergarten classrooms (1,868 four-year-old children). The findings support both construct and predictive validity of the teaching through interactions conceptual framework as assessed by the CLASS in Chile. Implications for cross-country comparison of quality of teacher-child interactions in prekindergarten classrooms are discussed.

  20. Relations Between Chile and ESO

    NASA Astrophysics Data System (ADS)

    1994-06-01

    As announced in an earlier Press Release (PR 08/94 of 6 May 1994), a high-ranking ESO delegation visited Santiago de Chile during the week of 24 - 28 May 1994 to discuss various important matters of mutual interest with the Chilean Government. It consisted of Dr. Peter Creola (President of ESO Council), Dr. Catherine Cesarsky (Vice-President of ESO Council), Dr. Henrik Grage (Former Vice-President of ESO Council) and Professor Riccardo Giacconi (ESO Director General), the latter accompanied by his advisers. THE SUPPLEMENTARY TREATY BETWEEN CHILE AND ESO Following a meeting with the ambassadors to Chile of the eight ESO member countries, the ESO delegation was received by the Chilean Minister of Foreign Affairs, Mr. Carlos Figueroa, and members of his staff. The ESO delegation was pleased to receive assurances that the present Chilean Government, like its predecessors, will continue to honour all contractual agreements, in particular the privileges and immunities of this Organisation, which were laid down in the Treaty between ESO and Chile that was signed by the parties in 1963 and ratified the following year. The discussions covered some aspects of the proposed Supplementary Treaty which has been under preparation during the past year. This included in particular the desire of the Chilean side to further increase the percentage of guaranteed time for Chilean astronomers at the future ESO Very Large Telescope (VLT) and also the rules governing the installation by ESO member countries of additional telescopes at the ESO observatories in Chile. ESO invited a Chilean delegation to visit the ESO Headquarters in Garching (Germany) later this year for the final adjustment of the text of the Supplementary Treaty, after which it should be possible to proceed rapidly with the signing and ratification by the Chilean Parliament and the ESO Council. THE SITUATION AROUND PARANAL The ESO delegation expressed its deep concern to the Chilean Government about the continuing legal

  1. The intersection of climate, tectonic uplift, and regional groundwater flow in the central Andean Plateau: Insight from the accumulation of the massive evaporite deposit in the Salar de Atacama, Chile

    NASA Astrophysics Data System (ADS)

    Boutt, D. F.; Hynek, S. A.; Corenthal, L.; Munk, L. A.

    2015-12-01

    The Salar de Atacama (SdA), a large endorheic basin adjacent to the Central Andes in the hyperarid Atacama Desert, has accumulated over 1800 km3 of evaporites and a lithium-rich brine since the late Miocene. Focused groundwater discharge in endorheic basins, such as those in the Chilean Altiplano, provide opportunities to investigate mechanisms for closing hydrologic budgets in arid regions. We demonstrate that modern evapotranspiration is 5 to 21 times greater than modern recharge from precipitation in the topographic watershed. Multiple lines of evidence including an adapted chloride mass balance method applied to remotely sensed precipitation estimates and sodium mass balance calculations support this conclusion. We contend that the missing water needed to close the extreme hydrologic imbalance of SdA is sourced from recharge on the orogenic plateau in an area over 4 times larger than the topographic watershed, augmented by transient draining of stored groundwater. Groundwater recharged during wetter periods in the late Pleistocene is still actively draining and discharging from storage without corresponding recharge into the system. Geologic evidence from the volume of evaporites deposited in the basin suggests that the SdA has been receiving significant amounts of fresh inflow waters over at least 7 Ma despite the region being hyperarid over the same time frame. Our conceptualization of the depositional model for evaporite accumulation necessitates the water table being at or close to the land surface. Subsidence associated with basin development has accommodated significant accumulation of these deposits thereby requiring the sustenance of fresh inflow waters during uplift of the Andean plateau. Sustained groundwater discharge to the basin requires long residence times, deep water tables and strong gradients in landscape and climate enabled by an uplifting plateau. The application of steady state assumptions to the modern hydrologic system are unsupported by

  2. Spatial and temporal variability of planktonic archaeal abundance in the Humboldt Current System off Chile

    NASA Astrophysics Data System (ADS)

    Quiñones, Renato A.; Levipan, Héctor A.; Urrutia, Homero

    2009-07-01

    The latest advances in the field of microbial ecology have shown that planktonic Archaea are one of the most abundant unicellular microorganisms of the oceans. However, no information is available on the contribution this group makes to the prokaryote assemblages that inhabit the eastern South Pacific Ocean. Here, we describe the relative abundance and vertical distribution of planktonic Archaea off northern and central-southern Chile. Data come from several cruises and a 45-month time series at a station located on the shelf off central-southern Chile. Both the taxonomic composition of the prokaryote community and its relative abundance were determined using quantitative dot blot 16S-rRNA hybridizations. Total Archaea in central-southern Chile made up 6-87% of the prokaryote rRNA in the water column and did not present evidence of any seasonal pattern. Crenarchaea were the most abundant archaeal group at this site and were significantly associated with the ammonium concentration ( r2=0.16, p=0.0003, n=80). Archaeal abundance in the time series was usually greater in the deeper layer (>50 m), with contributions reaching up to ˜90% of the prokaryote rRNA on certain occasions, and decreasing towards the surface. Important increments in the relative abundance of total Archaea were observed on given dates at the surface of the time-series station off central-southern Chile. Off northern Chile, total Archaea normally contributed from ˜10% to 50% of the prokaryote rRNA found between 10 and 1000 m, and were generally important in the mesopelagic realm. Our results indicate that Archaea constitute an important fraction of the prokaryote assemblage in the water column of the Humboldt Current System, especially in the oxygen minimum zone.

  3. [Blood supply during disasters: the experience of Chile in 2010].

    PubMed

    Vásquez, Marcela; Maldonado, Mónica; Tagle, Federico; León, Sergio; Soto, Alejandra; Mena, Aaron; Toro, Carla

    2011-05-01

    A review of the management of blood supply and its administration during disasters was conducted based on the experience of several events that occurred primarily from 2000-2010, particularly the earthquake that measured 8.8 on the Richter scale that struck central and southern Chile on 27 February 2010. The objective was to provide information that could be useful in improving response plans and strategies during potential future disasters. The descriptive information on response procedures was obtained from interviews, internal reports, and the computer database from the Maule regional blood production center. The results lead to the conclusion that to respond efficiently and effectively to the need for blood in the immediate wake of a disaster it is essential to have both a centralized management system that facilitates the supply and administration of blood and volunteers with competence in health that are willing to swiftly arrive during these events. A change in the profile of blood donors during such emergencies was also observed. In Chile, for example, during the two weeks after the earthquake, the ratio of male/female donors was reversed. There was 61.1% participation by women, whereas in the week before the event women accounted for only 37%.

  4. Current Discussions Between ESO and Chile

    NASA Astrophysics Data System (ADS)

    1995-04-01

    [Joint Press Release by the Government of the Republic of Chile and the European Southern Observatory. The text is issued simultaneously in Santiago de Chile (in Spanish) and at the ESO Headquarters in Garching (in English).] Today, Tuesday, 18 April 1995, at the ESO Headquarters in Garching (Germany), Mr. Roberto Cifuentes, Plenipotentiary Ambassador representing the Government of the Republic of Chile, and the Director General of the European Southern Observatory, Professor Riccardo Giacconi, have signed a Supplementary, Interpretative and Amending Agreement to the Convention of 6 November 1963 which governs the relations between Chile and this International Organisation. This Agreement which in practice signifies a widening and strengthening of the cooperative relations between the Organisation and the Chilean scientific community will hereafter be submitted for ratification by the National Congress of the Republic of Chile (the Parliament) and by the ESO Council. According to the Agreement signed today, Chilean astronomers will have privileged access within up to 10 percent observing time on all present and future ESO telescopes in Chile. Moreover, ESO accepts to incorporate into its labour regulations for Chilean personnel concepts like freedom of association and collective bargaining. This signing of the Supplementary, Interpretative and Amending Agreement to the original Convention of 1963 follows after months of constructive dialogue between the parties. It constitutes an important step towards a solution of some of the pending points on the current agenda for discussions between the Government of Chile and ESO. Among the issues still pending, ESO has informed the Government of Chile that respect for its immunities by the Chilean State is of vital importance for the continuation of the construction of the world's largest telescope at Paranal, as well as the continued presence of the Organisation in Chile. The Chilean Government, on its side, and concerning

  5. Village microgrids: The Chile project

    SciTech Connect

    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.

  6. [Geographic variation of the fox Lycalopex culpaeus (Mammalia, Canidae) in Chile: taxonomic implications].

    PubMed

    Guzmán, Jonathan A; D'Elía, Guillermo; Ortiz, Juan Carlos

    2009-01-01

    We studied the geographic variation of skulls of Lycalopex culpaeus using qualitative and quantative analyses. The sampling area covered Chile, from its northern portion, to Tierra del Fuego and the neighbouring Hoste Island, as well as part of Argentina. Five subespecies are currently recognized from this large area. We found two morphotypes that are segregated geographically. Both groups mostly differ by morphometric attributes, followed by qualitative features. Specimens from northern Chile (Tarapacá and Antofagasta) have small skulls, short rostrum, a liriform sagital zone, and lack the interparietal crest. The second group is formed by specimens from north-western and central Argentina, central-south Chile, Patagonia, and the austral islands of Tierra del Fuego and Hoste. This group presents a strong sagital crest, large rostrum, and a large skull. Our results agree with observed patterns of mitochondrial DNA variation. We propose to retain the name L. c. andinus for the populations of northern Chile and to synonymize L. c. magellanicus, L. c. lycoides, and L. c. smithersi under L. c. culpaeus.

  7. Advances in ammonite biostratigraphy of the marine Atacama basin (Lower Cretaceous), northern Chile, and its relationship with the Neuquén basin, Argentina

    NASA Astrophysics Data System (ADS)

    Mourgues, Francisco Amaro

    2004-09-01

    Preliminary results about the Lower Cretaceous ammonite biostratigraphy of northern Chile reveal eight fossiliferous levels: Lower-Upper Valanginian neocomitid and olcostephanid faunas in the Punta del Cobre and Abundancia Formations and Upper Hauterivian-Barremian crioceratid in the Nantoco, Totoralillo, and Pabellón Formations. The faunal affinities with the Neuquén are strong during the Valanginian and Hauterivian. In contrast, during the Barremian and Aptian, the ammonites show affinities with Austral, California, and Tethys basinal faunas. The Lower Valanginian-lower Upper Aptian series in northern Chile comprises two sedimentary cycles separated by a regressive pulse of Upper Hauterivian-Lower Barremian age. This pulse may be equivalent to the regression that ended the Early Cretaceous marine cycle in central Chile and central west Argentina, where the second marine sedimentary cycle observed in northern Chile is not represented.

  8. Public Information and Education in Chile

    NASA Astrophysics Data System (ADS)

    Argandona, G.; Mirabel, F.

    2005-09-01

    One of the initiatives of ESO in Chile is the strengthening of the links with Chilean and Latin American media, to provide the information needed to educate the public in Latin America on the latest advancements in astronomy and astrophysics. This initiative has produced a considerable increase in the media coverage of ESO science activities, as described in Figure 1, which shows the evolution in the number of media publications in Chile on recent achievements at ESO.

  9. Where Do Mexico and Chile Stand on Inclusive Education? Short Title: Inclusion in Mexico and Chile

    ERIC Educational Resources Information Center

    García-Cedillo, Ismael; Romero-Contreras, Silvia; Ramos-Abadie, Liliana

    2015-01-01

    This paper discusses the background, current situation and challenges of educational integration and inclusive education in Mexico and Chile. These countries obtained similar low results on the academic achievement of their students (Mexico last and Chile second last) among OECD countries; and above average scores, among Latin-American countries.…

  10. [Papillomavirus and cervical cancer in Chile].

    PubMed

    O'Ryan, Miguel; Valenzuela, María Teresa

    2008-11-01

    Molecular, clinical and epidemiological studies have established beyond doubt that human papiloma viruses (HPV) cause cervical cancer. The virus is also associated with genital warts and other less common cancers in oropharynx, vulva, vagina and penis. Worldwide, VPH genotypes 16 and 18 are the most common high risk genotypes, detected in near 70% of women with cervical cancer. The discovery of a cause-effect relationship between several carcinogenic microorganisms and cancer open avenues for new diagnostic, treatment and prevention strategies. In this issue of Revista Médica de Chile, two papers on HPV are presented. Guzman and colleagues demonstrate that HPV can be detected in 66% to 77% of healthy male adolescents bypolymerase chain reaction and that positivity depends on the site of the penis that is sampled. These results support the role of male to female transmission of high risk HPVs in Chile and should lead to even more active educational campaigns. The second paper provides recommendations for HPV vaccine use in Chile, generated by the Immunization Advisory Committee of the Chilean Infectious Disease Society. To issue these recommendations, the Committee analyzes the epidemiological information available on HPV infection and cervical cancer in Chile, vaccine safety and effectiveness data, and describes cost-effectiveness studies. Taking into account that universal vaccination is controversial, the Committee favors vaccine use in Chile and it's incorporation into a national program. However, there is an indication that the country requires the implementation of an integrated surveillance approach including cross matching of data obtained from HPV genotype surveillance, monitoring of vaccination coverage, and surveillance of cervical cancer. The final decision of universal vaccine use in Chile should be based on a through analysis of information.ev Mid Chile

  11. Palaeoindian occupation of the Atacama Desert, northern Chile

    NASA Astrophysics Data System (ADS)

    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.

  12. Identification of trypanosomes isolated from reduviidae from north Chile.

    PubMed

    Schaub, G A; Schottelius, J

    1984-01-01

    Examination of 54 Triatoma infestans from a village near the European Southern Observatory La Silla in Chile and of 9 Triatoma spinolai from the territory of the observatory showed that 10 T. infestans were infected with trypanosomatids. Mice were infected with in vitro cultures initiated with five different trypanosomatid isolates and treated with the immunosuppressive drug cyclophosphamide to increase the parasitemia of the flagellates. Evidence of the presence of T. cruzi was provided by a comparative biometrical analysis of blood trypomastigotes and the occurrence of intracellular amastigotes. Three methods for further identification were used: examination of kDNA ultrastructure, disc electrophoresis of soluble proteins and the Aaptos papillata II lectin induced agglutination. We obtained the following results for all isolates: (1) presence of a central band of the kDNA; (2) T. cruzi specific double bands of the protein patterns; (3) positive reaction with Aaptos papillata II. No differences between the five isolates from Chile and T. cruzi or T. cruzi-like strains from other countries could be observed. Based on these results an infection of the bugs with T. rangeli and T. conorhini could be excluded. PMID:6421021

  13. Identification of trypanosomes isolated from reduviidae from north Chile.

    PubMed

    Schaub, G A; Schottelius, J

    1984-01-01

    Examination of 54 Triatoma infestans from a village near the European Southern Observatory La Silla in Chile and of 9 Triatoma spinolai from the territory of the observatory showed that 10 T. infestans were infected with trypanosomatids. Mice were infected with in vitro cultures initiated with five different trypanosomatid isolates and treated with the immunosuppressive drug cyclophosphamide to increase the parasitemia of the flagellates. Evidence of the presence of T. cruzi was provided by a comparative biometrical analysis of blood trypomastigotes and the occurrence of intracellular amastigotes. Three methods for further identification were used: examination of kDNA ultrastructure, disc electrophoresis of soluble proteins and the Aaptos papillata II lectin induced agglutination. We obtained the following results for all isolates: (1) presence of a central band of the kDNA; (2) T. cruzi specific double bands of the protein patterns; (3) positive reaction with Aaptos papillata II. No differences between the five isolates from Chile and T. cruzi or T. cruzi-like strains from other countries could be observed. Based on these results an infection of the bugs with T. rangeli and T. conorhini could be excluded.

  14. A diverse assemblage of fossil hardwood from the Upper Tertiary (Miocene?) of the Arauco Peninsula, Chile

    NASA Astrophysics Data System (ADS)

    Schöning, Meike; Bandel, Klaus

    2004-09-01

    Silicified woods of 10 dicotyledonous tree families of probably Miocene age from the Arauco Peninsula, central Chile are described and classified according to their anatomy. The diversity is surprisingly high, in that of the 19 samples analyzed, virtually every one could belong to a different species of tree or shrub. Almost all species document a damp climate, and most have related species living in the central zone of modern Chile. The samples were collected in a narrow zone on Punta El Fraile, west of the town of Arauco. The following families are based on woods from the Arauco Peninsula: Anacardiaceae, Boraginaceae, Euphorbiaceae, Fagaceae, Lauraceae, Leguminosae, Monimiaceae, the first report of fossil Myristicaceae, Myrtaceae, and Proteaceae. Their diagenetic history is connected to tuffaceous material and calcareous concretions.

  15. Metagenome Sequencing of the Microbial Community of a Solar Saltern Crystallizer Pond at Cáhuil Lagoon, Chile

    PubMed Central

    Plominsky, Alvaro M.; Delherbe, Nathalie; Ugalde, Juan A.; Allen, Eric E.; Blanchet, Marine; Ikeda, Priscila; Santibañez, Francisco; Hanselmann, Kurt; Ulloa, Osvaldo; De la Iglesia, Rodrigo; von Dassow, Peter; Astorga, Marcia; Gálvez, María Jesús; González, María Lorena; Henríquez-Castillo, Carlos; Vaulot, Daniel; Lopes do Santos, Adriana; van den Engh, Gerrit; Gimpel, Carla; Bertoglio, Florencia; Delgado, Yolaine; Docmac, Felipe; Elizondo-Patrone, Claudia; Narváez, Silvia; Sorroche, Fernando; Rojas-Herrera, Marcelo

    2014-01-01

    Cáhuil Lagoon in central Chile harbors distinct microbial communities in various solar salterns that are arranged as interconnected ponds with increasing salt concentrations. Here, we report the metagenome of the 3.0- to 0.2-µm fraction of the microbial community present in a crystallizer pond with 34% salinity. PMID:25395641

  16. Interactions Between Trypanosoma cruzi the Chagas Disease Parasite and Naturally Infected Wild Mepraia Vectors of Chile.

    PubMed

    Campos-Soto, Ricardo; Ortiz, Sylvia; Cordova, Ivan; Bruneau, Nicole; Botto-Mahan, Carezza; Solari, Aldo

    2016-03-01

    Chagas disease, which ranks among the world's most neglected diseases, is a chronic, systemic, parasitic infection caused by the protozoan Trypanosoma cruzi. Mepraia species are the wild vectors of this parasite in Chile. Host-parasite interactions can occur at several levels, such as co-speciation and ecological host fitting, among others. Thus, we are exploring the interactions between T. cruzi circulating in naturally infected Mepraia species in all areas endemic of Chile. We evaluated T. cruzi infection rates of 27 different haplotypes of the wild Mepraia species and identified their parasite genotypes using minicircle PCR amplification and hybridization tests with genotype-specific DNA probes. Infection rates were lower in northern Chile where Mepraia gajardoi circulates (10-35%); in central Chile, Mepraia spinolai is most abundant, and infection rates varied in space and time (0-55%). T. cruzi discrete typing units (DTUs) TcI, TcII, TcV, and Tc VI were detected. Mixed infections with two or more DTUs are frequently found in highly infected insects. T. cruzi DTUs have distinct, but not exclusive, ecological and epidemiological associations with their hosts. T. cruzi infection rates of M. spinolai were higher than in M. gajardoi, but the presence of mixed infection with more than one T. cruzi DTU was the same. The same T. cruzi DTUs (TcI, TcII, TcV, and TcVI) were found circulating in both vector species, even though TcI was not equally distributed. These results suggest that T. cruzi DTUs are not associated with any of the two genetically related vector species nor with the geographic area. The T. cruzi vectors interactions are discussed in terms of old and recent events. By exploring T. cruzi DTUs present in Mepraia haplotypes and species from northern to central Chile, we open the analysis on these invertebrate host-parasite interactions.

  17. Helicobacter pylori infection in Chile.

    PubMed

    Figueroa, G; Acuña, R; Troncoso, M; Portell, D P; Toledo, M S; Valenzuela, J

    1997-11-01

    This article summarizes studies designed to evaluate the role of Helicobacter pylori infection in Chile, described in 21 reports from nine centers in various Chilean regions published between 1985 and 1995. According to their data, H. pylori infection is quite frequent among patients with a variety of gastric conditions, including adults (43%-92%) and children (6%-100%). Levels of specific IgG antibodies to H. pylori are also elevated among patients with duodenal ulcers (100%) and gastritis (86%) as well as asymptomatic adults (75%). Combination therapy with three (but not two) drugs has been proved effective, with clinical improvement, ulcer cure, and H. pylori eradication occurring in well-controlled studies. Available evidence suggests that antibiotic resistance is not a major problem in treatment. The H. pylori reinfection rate is low (4.2% per year), suggesting that combination therapy with three drugs constitutes a cost-effective alternative for treating colonized symptomatic patients. Concurrent preliminary studies revealed that antibodies to VacA but not CagA proteins correlate with disease severity in Chilean patients. It can be concluded that local research assists local administrators of health resources to implement adequate policies to prevent, control, and treat H. pylori-related pathologies.

  18. [Beginning of the Microbiology education in Chile: formation centers].

    PubMed

    Osorio, Carlos

    2015-08-01

    The first Chair of Microbiology in Chile was created in the School of Medicine of the Cañadilla at the University of Chile in 1892. Dr. Alejandro del Río Soto Aguilar was its first Professor. For almost three decades it was the only educational center for microbiologists in Chile. Among them were the first Professors of the new School of Medicine of the Catholic University of Chile and of the University of Concepción.

  19. Non university sources of science in Chile

    NASA Astrophysics Data System (ADS)

    Soto, Leopoldo

    2016-05-01

    The following ideas are widely accepted in Chile with respect to scientific activity: is carried out mainly in universities and science is considered a naturally university activity, that was developed in a period of more than 150 years by isolated individual efforts, c) it was transformed into an institutionalized activity at the universities after the university reform movement at the end of the 1960 decade, d) the activity is finally institutionalized in the country with the creation of the “Comisión Nacional de Investigatión Científica y Tecnológica, CONICYT (National Commission for Scientific and Technological Research) in 1967. This work presents preliminary findings showing that there are other institutional initiatives, different to the efforts from universities and directly dependent of the Chilean Government, in order to produce science and technology in Chile. This governmental initiatives start at the beginning of the Republic of Chile circa of 1810.

  20. Reforming health insurance in Argentina and Chile.

    PubMed

    Barrientos, A; Lloyd-Sherlock, P

    2000-12-01

    The paper examines the recent reforms of health insurance in Chile and Argentina. These partially replace social health insurance with individual insurance administered through the private sector. In Chile, reforms in the early 1980s allowed private health insurance funds to compete for affiliates with the social health insurance system. In Argentina, reforms in the 1990s aim to open up the union-administered social insurance system to competition both internally and from private insurers. The paper outlines the specific articulation of social and individual health insurance produced by these reforms, and discusses the implications for health insurance coverage, inequalities in access to healthcare, and health expenditures.

  1. Assessing the performance of hybrid CSP+PV plants in northern Chile

    NASA Astrophysics Data System (ADS)

    Starke, Allan; Cardemil, José M.; Escobar, Rodrigo; Colle, Sergio

    2016-05-01

    The electricity systems in Chile are characterized by a variable hourly demand in the central grid and an almost constant demand in the northern grid, which require different operation strategies for solar power plants depending on their location. Hybridizing a CSP plant with a PV plant can increase the whole plant capacity factor by allowing thermal energy to be stored while the PV plant is in production and thus help to achieve a fully dispatchable solar electricity production system. A thermal and economic analysis of hybrid CSP+PV plants is conducted considering a range of plant capacities based on a parabolic trough plant with the addition of a PV plant for the environmental conditions of Crucero in Northern Chile, which is a hotspot for solar energy development in the country. The study considers a parametric analysis and optimization of the storage and power block sizes for the CSP plant in terms of the levelized cost of energy (LCOE) for varying PV plant nominal capacity. The annual production of the plants are calculated by using the Transient System Simulation program (TRNSYS), which uses a new component library developed for that purpose. The results show good agreement with other software packages as well as with actual data from currently operating CSP plants. The adopted approach helps the proper assessment of the integration of different technologies, since it uses the well-kwon modular structure of the TRNSYS. Regarding the potential for the hybrid solar-solar plants in the Atacama Desert, the high level of irradiation available in Chile can provide a competitive electricity cost, allowing to investors the access to PPA contracts with mining companies in northern Chile. Additionally, the optimization analysis shows that the northern regions of Chile present an outstanding potential for the deployment of such projects.

  2. A systems approach to chile harvest mechanization

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This article reviews nearly half a century of published research on harvest mechanization of C. annuum var. annuum cultivars, focusing on chile for canning and fresh markets. At present, most of the crop is still harvested by hand, displacing production to locations where labor costs are low. Mech...

  3. Education of the Televiewer in Chile.

    ERIC Educational Resources Information Center

    Reyes, Miguel T.

    This paper begins with a discussion of the origins of Chilean television, including its channels, programs, and transmission times, and how education for television has arisen in Chile as a defense against its influence. The initial concern of sociologists' about this influence and later development of ideas and programs by a number of…

  4. Vibrio parahaemolyticus Diarrhea, Chile, 1998 and 2004

    PubMed Central

    González-Escalona, Narjol; Cachicas, Viviana; Acevedo, Claudia; Rioseco, María L.; Vergara, Juan A.; Cabello, Felipe; Romero, Jaime

    2005-01-01

    Analysis of clinical isolates of Vibrio parahaemolyticus from outbreaks in Chile in the cities of Puerto Montt in 2004 and in Antofagasta in 1998 indicated that 23 of 24 isolates from Puerto Montt and 19 of 20 from Antofagasta belonged to the pandemic clonal complex that emerged in Southeast Asia in 1996. PMID:15705337

  5. Bat rabies in urban centers in Chile.

    PubMed

    de Mattos, C A; Favi, M; Yung, V; Pavletic, C; de Mattos, C C

    2000-04-01

    One hundred and five rabies isolates obtained from domestic animals and insectivorous bats in Chile between 1977 and 1998 were molecularly characterized by limited sequence analysis of their nucleoprotein genes. These isolates were compared with viruses isolated from known domestic and wildlife rabies reservoirs in the Americas to identify potential reservoirs of rabies in Chile. The phylogenetic analyses showed that none of the Chilean isolates segregated with viruses from the terrestrial reservoirs. No non-rabies lyssaviruses were found in this study. The Chilean samples were not related to viruses of the sylvatic cycle maintained by the common vampire bat (Desmodus rotundus) in Latin America. Five genetic variants were identified from insectivorous bats in Chile. The Brazilian free-tailed bat (Tadarida brasiliensis) was identified as the reservoir for the rabies genetic variant most frequently isolated in the country between 1977 and 1998. The close association of a group of viruses obtained from a domestic dog (Canis familiaris), Brazilian free-tailed bats, and a red bat (Lasiurus borealis) with viruses maintained by Lasiurus spp. in North America implicated species of this genus as the possible reservoirs of this particular genetic variant in Chile. Reservoirs for the other three variants remain unknown. PMID:10813604

  6. 27 CFR 9.154 - Chiles Valley.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... southwest corner of Rancho Catacula in section 34, T8N, R4W on the Yountville, CA, quadrangle map; (9) Then... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Chiles Valley. 9.154 Section 9.154 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU,...

  7. 27 CFR 9.154 - Chiles Valley.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... southwest corner of Rancho Catacula in section 34, T8N, R4W on the Yountville, CA, quadrangle map; (9) Then... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Chiles Valley. 9.154 Section 9.154 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU,...

  8. 27 CFR 9.154 - Chiles Valley.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... southwest corner of Rancho Catacula in section 34, T8N, R4W on the Yountville, CA, quadrangle map; (9) Then... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Chiles Valley. 9.154 Section 9.154 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU,...

  9. 27 CFR 9.154 - Chiles Valley.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... southwest corner of Rancho Catacula in section 34, T8N, R4W on the Yountville, CA, quadrangle map; (9) Then... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Chiles Valley. 9.154 Section 9.154 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU,...

  10. 27 CFR 9.154 - Chiles Valley.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... southwest corner of Rancho Catacula in section 34, T8N, R4W on the Yountville, CA, quadrangle map; (9) Then... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Chiles Valley. 9.154 Section 9.154 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU,...

  11. Fundamentals of Moral Education in Chile.

    ERIC Educational Resources Information Center

    Vidal, Giaume

    1980-01-01

    Moral education is not included in the curriculum, but the history of Chile shows the influence of European culture. Therefore a philosophy of education which promotes an autonomous human being has usually underlined educational policy. The influence of Catholicism has been very strong both in school curriculum and parent attitudes. (Author/SJL)

  12. [Notes about other epidemics in Colonial Chile].

    PubMed

    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

  13. The Aftershock Analyses of 27 February 2010 Chile M=8.8 Mega Earthquake

    NASA Astrophysics Data System (ADS)

    Lee, C.-S.; Klingelhoefer, F.; Gutscher, M.; Miller, M.; Gallardo, V.

    2012-04-01

    In 1960, the biggest earthquake (M=9.5), the human ever recorded event, occurred in south Chile. Subsequently several mega earthquake (M >8) occurred, including the M=8.8 earthquake in 2010. This reflects that an incomplete release of tectonic energy exists in the Chile subduction system. The west coast of Chile is a long convergence plate boundary between the Nazca and the South American plate. The Nazca Plate subducts beneath the South American Plate toward the northeast with a convergence rate of about 6.5 cm/year, accumulating the stress in the lower part of the subducted plate to some extent resulting in destructive ruptures. On 27 February 2010, the Maule mega earthquake (M=8.8) occurred offshore central Chile. The epicenter (35.9° S, 72.73° W) is located at 115 km, NE of Concepción, the second biggest city in Chile. The main shock was a thrust-type subduction earthquake where the Nazca Plate subducted into the South America Plate (the Chile subduction system). The focal depth of main shock is 35 km which caused more than 500-km long rupture in the accretionary prism and produced a destructive tsunami of more than 20 m. It killed several hundreds of people and damaged countless buildings. Even up to today, aftershocks and volcanic activities continue to occur in this region. During May-August of last year, we shipped 20 OBSs to Chile and conducted two aftershock surveys in the tsunami-affected area. The OBSs recorded more than 4,000 aftershock events, magnitude from M=6.0 to 1.0. Results show that the aftershock data were concentrated into two masses: the landward side of the paleo-accretionary prism and the seaward side of the subducting plate, leaving a "white zone" in the frontal accretionary prisms. Both data sets consistently indicate the same result. The angle between the paleo-accretionary prism and the subduction plate seems to be greater than that of the frontal-accretionary prism. We suggest that the greater of the splay fault angle the higher

  14. Feeding profile of Mepraia spinolai, a sylvatic vector of Chagas disease in Chile.

    PubMed

    Chacón, F; Bacigalupo, A; Quiroga, J F; Ferreira, A; Cattan, P E; Ramírez-Toloza, G

    2016-10-01

    American trypanosomiasis is a chronic disease transmitted mainly by vectors. The hematophagous triatomine vectors transmit Trypanosoma cruzi to a wide variety of mammals, which usually are their food source. This study determined the feeding profile of Mepraia spinolai, a sylvatic triatomine vector, present in endemic areas of Chile. Vectors were captured in the north-central area of Chile. Samples of intestinal contents were analyzed by an Enzyme-linked immunosorbent assay (ELISA) that identifies and discriminates the presence of serum antigens from Homo sapiens and nine animal species (Canis familiaris, Felis catus, Capra hircus, Mus musculus, Gallus gallus, Octodon degus, Thylamys elegans, Phyllotis darwini and Oryctolagus cuniculus). Our data indicate the most frequent feeding source in this area was P. darwini, followed by O. degus, O. cuniculus, M. musculus, G. gallus, T. elegans, C. familiaris, F. catus and C. hircus. Mixed food sources were also identified.

  15. Feeding profile of Mepraia spinolai, a sylvatic vector of Chagas disease in Chile.

    PubMed

    Chacón, F; Bacigalupo, A; Quiroga, J F; Ferreira, A; Cattan, P E; Ramírez-Toloza, G

    2016-10-01

    American trypanosomiasis is a chronic disease transmitted mainly by vectors. The hematophagous triatomine vectors transmit Trypanosoma cruzi to a wide variety of mammals, which usually are their food source. This study determined the feeding profile of Mepraia spinolai, a sylvatic triatomine vector, present in endemic areas of Chile. Vectors were captured in the north-central area of Chile. Samples of intestinal contents were analyzed by an Enzyme-linked immunosorbent assay (ELISA) that identifies and discriminates the presence of serum antigens from Homo sapiens and nine animal species (Canis familiaris, Felis catus, Capra hircus, Mus musculus, Gallus gallus, Octodon degus, Thylamys elegans, Phyllotis darwini and Oryctolagus cuniculus). Our data indicate the most frequent feeding source in this area was P. darwini, followed by O. degus, O. cuniculus, M. musculus, G. gallus, T. elegans, C. familiaris, F. catus and C. hircus. Mixed food sources were also identified. PMID:27349188

  16. Incubation of Chile's 1960 Earthquake

    NASA Astrophysics Data System (ADS)

    Atwater, B. F.; Cisternas, M.; Salgado, I.; Machuca, G.; Lagos, M.; Eipert, A.; Shishikura, M.

    2003-12-01

    Infrequent occurrence of giant events may help explain how the 1960 Chile earthquake attained M 9.5. Although old documents imply that this earthquake followed great earthquakes of 1575, 1737 and 1837, only three earthquakes of the past 1000 years produced geologic records like those for 1960. These earlier earthquakes include the 1575 event but not 1737 or 1837. Because the 1960 earthquake had nearly twice the seismic slip expected from plate convergence since 1837, much of the strain released in 1960 may have been accumulating since 1575. Geologic evidence for such incubation comes from new paleoseismic findings at the R¡o Maullin estuary, which indents the Pacific coast at 41.5§ S midway along the 1960 rupture. The 1960 earthquake lowered the area by 1.5 m, and the ensuing tsunami spread sand across lowland soils. The subsidence killed forests and changed pastures into sandy tidal flats. Guided by these 1960 analogs, we inferred tsunami and earthquake history from sand sheets, tree rings, and old maps. At Chuyaquen, 10 km upriver from the sea, we studied sand sheets in 31 backhoe pits on a geologic transect 1 km long. Each sheet overlies the buried soil of a former marsh or meadow. The sand sheet from 1960 extends the entire length of the transect. Three earlier sheets can be correlated at least half that far. The oldest one, probably a tsunami deposit, surrounds herbaceous plants that date to AD 990-1160. Next comes a sandy tidal-flat deposit dated by stratigraphic position to about 1000-1500. The penultimate sheet is a tsunami deposit younger than twigs from 1410-1630. It probably represents the 1575 earthquake, whose accounts of shaking, tsunami, and landslides rival those of 1960. In that case, the record excludes the 1737 and 1837 events. The 1737 and 1837 events also appear missing in tree-ring evidence from islands of Misquihue, 30 km upriver from the sea. Here the subsidence in 1960 admitted brackish tidal water that defoliated tens of thousands of

  17. Geomorphic surfaces and supergene enrichment in Northern Chile.

    NASA Astrophysics Data System (ADS)

    Evenstar, Laura; Mather, Anne; Stuart, Finlay; Cooper, Frances; Sparks, Steve

    2014-05-01

    Supergene enrichment of porphyry copper deposits in the central Andes is thought to be closely correlated with periods of relatively humid climate and the formation of regionally extensive paleosurfaces (e.g. Mortimer, C. 1973) . In northern Chile, two such paleosurfaces have been proposed: the ca. 23 Ma Tarapaca paleosurface within the Coastal Cordillera, and the ca. 10 Ma Pacific paleosurface within the Longitudinal Valley. The Pacific paleosurface is regarded as a single stratigraphic horizon that formed due to either a marked increase in the aridity of the area (Galli-Oliver 1967), regional surface uplift that created a change in the locus of deposition (e.g. Mortimer and Rendic 1975), or a combination of the two. The formation of this surface has been associated with the timing of supergene enrichment throughout the northern Chile and southern Peru (Alpers and Brimhall 1988). Multispectral satellite mapping of the Pacific paleosurface in northern Chile using Landsat, Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) and Digital Elevation Model (DEM) imagery, combined with seismic data (Jordan et al. 2010) indicates that the Pacific paleosurface is not a single chronostratigraphic surface, as previously thought, but an amalgamation of surfaces that have both an erosional and depositional history. New in situ cosmogenic exposure dating of alluvial boulders on the paleosurface is combined with previous data (Dunai et al. 2005, Kober et al. 2007 and Evenstar et al., 2009) giving ages ranging from ca. 23 Ma to <1 Ma, supporting a multiphase and much more continuous history. By combining these apparent exposure ages with regional geomorphology, underlying sedimentology, and seismic sections, the geomorphic evolution of the Longitudinal Valley can be constrained. The results show a complex interplay between uplift within the Coastal Cordillera and Precordillera in the south and a distinct change in depositional pattern towards the north. The

  18. Stigma Related to HIV among Community Health Workers in Chile

    PubMed Central

    Cianelli, Rosina; Ferrer, Lilian; Norr, Kathleen F.; McCreary, Linda; Irarrázabal, Lisette; Bernales, Margarita; Miner, Sarah

    2011-01-01

    Purpose When healthcare workers have stigmatizing attitudes toward people living with HIV it may lead to discriminatory behavior that interferes with prevention, treatment, and care. This research examined the HIV-related stigmatizing attitudes reported by health workers in Santiago, Chile. Methods The study used focus group data from the first phase of a larger study to develop and test a HIV prevention intervention for Chilean health workers. Ten focus groups were conducted with Health workers in two communities in Santiago, Chile. Content analysis was used to analyze the data. Results Two central themes emerged: Societal stigma and discrimination towards people living with HIV and healthcare system’s policies related to HIV. Both inaccurate fears of transmission among the general public and Chilean Health workers and societal prejudices against homosexuals contributed to stigmatization and discrimination. Conclusions Health workers did not recognize their own stigmatizing attitudes or discriminatory behaviors, but their discussion indicated that these behaviors and attitudes did exist. Healthcare system issues identified included problems with confidentiality due to the desire to inform other health workers about client HIV status. Health workers must be sensitized to the current stigmatization and misinformation associated with HIV and its negative impacts on persons living with HIV and the general community. Implications All clinical and non-clinical workers at community clinics need mandatory education for HIV prevention that focuses on changing attitudes as well as sharing knowledge. Also, the Chilean law protecting people living with HIV and the confidentiality of their medical care needs to be publicized, along with guidelines for its enactment in clinics and other health facilities. PMID:21687824

  19. Managing hazardous pollutants in Chile: arsenic.

    PubMed

    Sancha, Ana María; O'Ryan, Raul

    2008-01-01

    Chile is one of the few countries that faces the environmental challenge posed by extensive arsenic pollution, which exists in the northern part of the country. Chile has worked through various options to appropriately address the environmental challenge of arsenic pollution of water and air. Because of cost and other reasons, copying standards used elsewhere in the world was not an option for Chile. Approximately 1.8 million people, representing about 12% of the total population of the country, live in arsenic-contaminated areas. In these regions, air, water, and soil are contaminated with arsenic from both natural and anthropogenic sources. For long periods, water consumed by the population contained arsenic levels that exceeded values recommended by the World Health Organization. Exposure to airborne arsenic also occurred near several large cities, as a consequence of both natural contamination and the intensive mining activity carried out in those areas. In rural areas, indigenous populations, who lack access to treated water, were also exposed to arsenic by consuming foods grown locally in arsenic-contaminated soils. Health effects in children and adults from arsenic exposure first appeared in the 1950s. Such effects included vascular, respiratory, and skin lesions from intake of high arsenic levels in drinking water. Methods to remove arsenic from water were evaluated, developed, and implemented that allowed significant reductions in exposure at a relatively low cost. Construction and operation of treatment plants to remove arsenic from water first began in the 1970s. Beginning in the 1990s, epidemiological studies showed that the rate of lung and bladder cancer in the arsenic-polluted area was considerably higher than mean cancer rates for the country. Cancer incidence was directly related to arsenic exposure. During the 1990s, international pressure and concern by Chile's Health Ministry prompted action to regulate arsenic emissions from copper smelters. A

  20. Managing hazardous pollutants in Chile: arsenic.

    PubMed

    Sancha, Ana María; O'Ryan, Raul

    2008-01-01

    Chile is one of the few countries that faces the environmental challenge posed by extensive arsenic pollution, which exists in the northern part of the country. Chile has worked through various options to appropriately address the environmental challenge of arsenic pollution of water and air. Because of cost and other reasons, copying standards used elsewhere in the world was not an option for Chile. Approximately 1.8 million people, representing about 12% of the total population of the country, live in arsenic-contaminated areas. In these regions, air, water, and soil are contaminated with arsenic from both natural and anthropogenic sources. For long periods, water consumed by the population contained arsenic levels that exceeded values recommended by the World Health Organization. Exposure to airborne arsenic also occurred near several large cities, as a consequence of both natural contamination and the intensive mining activity carried out in those areas. In rural areas, indigenous populations, who lack access to treated water, were also exposed to arsenic by consuming foods grown locally in arsenic-contaminated soils. Health effects in children and adults from arsenic exposure first appeared in the 1950s. Such effects included vascular, respiratory, and skin lesions from intake of high arsenic levels in drinking water. Methods to remove arsenic from water were evaluated, developed, and implemented that allowed significant reductions in exposure at a relatively low cost. Construction and operation of treatment plants to remove arsenic from water first began in the 1970s. Beginning in the 1990s, epidemiological studies showed that the rate of lung and bladder cancer in the arsenic-polluted area was considerably higher than mean cancer rates for the country. Cancer incidence was directly related to arsenic exposure. During the 1990s, international pressure and concern by Chile's Health Ministry prompted action to regulate arsenic emissions from copper smelters. A

  1. [Risk groups for tuberculosis in Chile].

    PubMed

    Herrera, Tania

    2015-02-01

    Tuberculosis (TB) remains a major global and national problem. In Chile the incidence rate has remained at 13 per 100,000 inhabitants for several years without tendency to the expected decline that would allow their elimination by 2020. As a low prevalence country, TB cases have been concentrated in risk groups, reaching 33% in 2013, and this proportion increases as younger people are analyzed. The main risk groups in Chile are HIV co-infection, foreigners and population of prisons. By 2013, the proportion of cases for these three groups was 8.7%, 8.4% and 3.9% respectively, and these percentages vary significantly when regional situation is analyzed. In addition, many of these patients have more than one risk factor, demons-rating the existence of clusters more vulnerable to TB.

  2. [Risk groups for tuberculosis in Chile].

    PubMed

    Herrera, Tania

    2015-02-01

    Tuberculosis (TB) remains a major global and national problem. In Chile the incidence rate has remained at 13 per 100,000 inhabitants for several years without tendency to the expected decline that would allow their elimination by 2020. As a low prevalence country, TB cases have been concentrated in risk groups, reaching 33% in 2013, and this proportion increases as younger people are analyzed. The main risk groups in Chile are HIV co-infection, foreigners and population of prisons. By 2013, the proportion of cases for these three groups was 8.7%, 8.4% and 3.9% respectively, and these percentages vary significantly when regional situation is analyzed. In addition, many of these patients have more than one risk factor, demons-rating the existence of clusters more vulnerable to TB. PMID:25860037

  3. [Current status of medical education in Chile].

    PubMed

    2009-05-01

    The Chilean Academy of Medicine published a "Report on the Current Status of Medical Education in Chile". This report reviews the history of medical education in this country and its close relationship with the Health Care System, public and private; highlights the main changes that took place during the last 25 years in superior and medical education; provides information on the 26 currently existing Medical Schools; refers to the availability of medical doctors and specialists; discusses the mechanisms that control the quality of institutions involved and their programs; and summarizes the results of the Annual National Medical Examination. The members of the Committee on Superior Education of the Academy provided a critical analysis of medical education in Chile and recommendations on how to improve it.

  4. [Rabies in Chile: 1989-2005].

    PubMed

    Favi C, Myriam; Rodríguez A, Luis; Espinosa M, Carla; Yung P, Verónica

    2008-04-01

    A retrospective epidemiological study about epidemiology of rabies in Chile between years 1989 and 2005 was done. A data base of 39793 national registries of rabies samples was analyzed by means of statistical packages. Out of 39793 analyzed cases, 719 bats, 7 dogs, 7 cats, 1 bovine and 1 human were positive to rabies throughout the 17 years of this study. The statistical analysis established a significant increase in the proportions of positivity in bats, with predominance of variant 4 between the reservoirs. Given the complexity of the wild cycle of the rabies in Chile, it is necessary to maintain a program control of rabies, directed to educate people for a responsible possession of domestic animals, due to the risk of rabies transmission from bat to the susceptible species. PMID:18425219

  5. [Public health policies in Chile: seeking to regain trust].

    PubMed

    Cuadrado, Cristóbal

    2016-09-07

    Healthcare represents a key area in the public agenda. In the case of Chile, this central part of citizen demands has emerged with an increasing criticism of the health system, its actors and institutions, while a major democratic and legitimacy crisis in Chilean society unfolds. The starting point of this analysis is the link between the critical and widespread societal dissatisfaction with the legitimacy crisis in the health sector. There is an interdependence and parallelism between these two different aspects of the crisis. The analysis is built around the dimensions of trust and legitimacy as a potential driver of the conflict, taking as an analytical framework the socio-political matrix. Conceptual elements around the ideas of trust and legitimacy in public policies are reviewed. This article focuses on recent situations surrounding the dynamics of the Chilean health system such as the rise of the Instituciones de Salud Previsional (ISAPRE) and the market-driven health system, the failed health care reform of the last decade, conflicts of interest in the formulation of public policies, loss of legitimacy of healthcare authorities, and the role of the health professionals in this process. Finally, a discussion arises seeking to regain public trust as a central issue for the future development and sustainability of health policies.

  6. [Public health policies in Chile: seeking to regain trust].

    PubMed

    Cuadrado, Cristóbal

    2016-01-01

    Healthcare represents a key area in the public agenda. In the case of Chile, this central part of citizen demands has emerged with an increasing criticism of the health system, its actors and institutions, while a major democratic and legitimacy crisis in Chilean society unfolds. The starting point of this analysis is the link between the critical and widespread societal dissatisfaction with the legitimacy crisis in the health sector. There is an interdependence and parallelism between these two different aspects of the crisis. The analysis is built around the dimensions of trust and legitimacy as a potential driver of the conflict, taking as an analytical framework the socio-political matrix. Conceptual elements around the ideas of trust and legitimacy in public policies are reviewed. This article focuses on recent situations surrounding the dynamics of the Chilean health system such as the rise of the Instituciones de Salud Previsional (ISAPRE) and the market-driven health system, the failed health care reform of the last decade, conflicts of interest in the formulation of public policies, loss of legitimacy of healthcare authorities, and the role of the health professionals in this process. Finally, a discussion arises seeking to regain public trust as a central issue for the future development and sustainability of health policies. PMID:27602919

  7. Food, agricultural and marine biotechnology in Chile.

    PubMed

    Aguilera, J M; Agosin, E; San Martín, R

    1993-10-01

    Economic segments with highest growth rates in Chile are those based on renewable resources like agriculture (fruits and vegetables), marine and forest products. Opportunities for biotechnology are based on a sound scientific base at universities, adequate funding and incipient industry-academia relationships. However, there is an urgent need to develop the engineering capabilities required to scale-up processes and to design, build and operate industrial biotechnology plants.

  8. Education in Chile. Bulletin, 1945, No. 10

    ERIC Educational Resources Information Center

    Ebaugh, Cameron D.

    1945-01-01

    Chile is a republic 2,630 miles long, extending along the western coast of South America from Peru to the southernmost tip of the continent. In width it averages about 110 miles, with snow-capped, volcano-studded Andes in the East, a low coastal range along the Pacific and a string of valleys and plains in between. It is estimated that 5,000…

  9. [Geographical distribution of physicians in Chile].

    PubMed

    Goic, A

    1995-03-01

    In 1994, Chile had 15,451 active physicians (less than 70 years old) for a population of 14,027,344 with a ratio of 1 physician per 908 inhabitants, a satisfactory figure compared to other countries of similar socio-economical development. Ratios of 1:880 and 1:843 are projected for 1999 and 2004 respectively. The annual rate of physician's population growth (2.2%), that is superior to the general population's growth rate (1.6%), will increase to about 2.5% per annum in 2001 as a consequence of the creation of three new medical schools. However, the distribution of physicians along the country is unsatisfactory. While the capital (Metropolitan Region) has a ratio of 1 physician per 629 inhabitants, the figure for the Region of Maule is 1:2,113. Only two of ten regions, excepting the capital, have a ratio lower than 1:1,000. Sixty percent of physicians live in Santiago while only 40% of the general population does so, illustrating their high concentration. Median ratio in Chile, that better reflects the reality than the mean, is 1:1,280. The heterogeneous distribution of physicians in Chile is a sign of social inequity that must be corrected. In a free society a better physician distribution is achieved with economical and professional incentives given by health institutions.

  10. [Who finances medical research in Chile?].

    PubMed

    Reyes, H; Kauffmann, R; Goic, A

    1995-10-01

    To identify those institutions granting medical research in Chile, every issue of Revista Médica de Chile published between 1987 and 1994 was reviewed, under the assumption that a vast majority (over 70%) of papers released by Chilean authors in topics of internal medicine and related subspecialties would have been submitted for publication in this journal. This assumption was based in the solid prestige of Revista Médica de Chile among Chilean physicians and investigators: it is one of the oldest medical journals in the world (founded in 1872) and its inclusion in the most important international indexes (e.g. Index Medicus, Current Contents) qualifies it in the "mainstream literature". Papers classified as "Original Articles", "Clinical Experiences", "Review Articles", "Public Health", "Case Reports", "Clinical Laboratory", "Special Articles" and "Medical Education" were screened for acknowledgment of financial support beyond the resources needed for routine clinical work. Among 1,528 manuscripts published, 344 were "Original Articles" and 61.3% of them acknowledged special financial support. Five hundred and one manuscripts were "Clinical Experiences" and 21.5% of them received special financial support; similar proportions were detected in "Review Articles" and "Public Health" topics. The institution ranked as providing support most often was the "Fondo Nacional de Ciencias y Tecnología" (FONDECYT), a governmental fund that assigns resources to research in all areas of science and technology through a peer-reviewed nationwide annual contest. FONDECYT was identified as provider of financial support to 45.2% of the "Original Articles" and "Clinical Experiences"; Chilean universities were mentioned by 33.6% and other entities (including pharmaceutical companies, other national and foreign organizations) by 23.1%. The University of Chile was the main Chilean university mentioned in the acknowledgments. The proportion of papers receiving special financial support

  11. Plateurytion roigi sp. nov., a new geophilid centipede (Myriapoda: Chilopoda: Geophilomorpha) from Southern Chile.

    PubMed

    Pereira, Luis Alberto

    2016-09-09

    Plateurytion roigi sp. nov. (Chilopoda: Geophilomorpha: Geophilidae) is fully described and illustrated from the holotype female from southern Chile (Region X (de Los Lagos region): Palena province). The new species seems particularly similar to P. gracilis (Gervais, 1849) (from Chile and Argentina), to which it is accordingly compared in detail for a confident identification. This is the sixth report of a species of the genus Plateurytion Attems, 1909, from Chile. The others are P. gracilis (Gervais, 1849); P. metopias (Attems, 1903); P. michaelseni (Attems, 1903); P. mundus (Chamberlin, 1955); and P. zapallar (Chamberlin, 1955). New geographic records are given for Plateurytion mauryi Pereira, 2008, which is reported for the first time from San Juan province, up to now only known from the type locality (in Mendoza province), central-western Argentina. Plateurytion yungarum (Pereira, 2005), is reported from the montane cloud forest altitudinal level of the Yungas forest of northwestern Argentina, until now it has only been recorded from the (lowest) montane forest altitudinal level of the Yungas.

  12. Plateurytion roigi sp. nov., a new geophilid centipede (Myriapoda: Chilopoda: Geophilomorpha) from Southern Chile.

    PubMed

    Pereira, Luis Alberto

    2016-01-01

    Plateurytion roigi sp. nov. (Chilopoda: Geophilomorpha: Geophilidae) is fully described and illustrated from the holotype female from southern Chile (Region X (de Los Lagos region): Palena province). The new species seems particularly similar to P. gracilis (Gervais, 1849) (from Chile and Argentina), to which it is accordingly compared in detail for a confident identification. This is the sixth report of a species of the genus Plateurytion Attems, 1909, from Chile. The others are P. gracilis (Gervais, 1849); P. metopias (Attems, 1903); P. michaelseni (Attems, 1903); P. mundus (Chamberlin, 1955); and P. zapallar (Chamberlin, 1955). New geographic records are given for Plateurytion mauryi Pereira, 2008, which is reported for the first time from San Juan province, up to now only known from the type locality (in Mendoza province), central-western Argentina. Plateurytion yungarum (Pereira, 2005), is reported from the montane cloud forest altitudinal level of the Yungas forest of northwestern Argentina, until now it has only been recorded from the (lowest) montane forest altitudinal level of the Yungas. PMID:27615978

  13. Anthropogenic debris on beaches in the SE Pacific (Chile): results from a national survey supported by volunteers.

    PubMed

    Bravo, Macarena; de Los Angeles Gallardo, Ma; Luna-Jorquera, Guillermo; Núñez, Paloma; Vásquez, Nelson; Thiel, Martin

    2009-11-01

    Anthropogenic marine debris (AMD) is an ubiquitous problem, which has motivated public participation in activities such as beach surveys and clean-up campaigns. While it is known that beaches in the SE Pacific are also affected by this problem, the quantities and types of AMD remain largely unknown. In the context of an outreach project, volunteers (approximately 1500 high-school students) participated in a nation-wide survey of AMD on 43 beaches distributed randomly along the entire Chilean coast (18 degrees S to 53 degrees S). The mean density of AMD was 1.8 items m(-2) and the major types were plastics, cigarette butts and glass. Densities in central Chile were lower than in northern and southern Chile, which could be due to different attitudes of beach users or to intense beach cleaning in central regions. We suggest that public participation in surveys and cleaning activities will raise awareness and thereby contribute to an improvement of the situation.

  14. Taxonomic Treatment of Solanum Section Petota (Wild Potatoes) in Catálogo de Plantas Vasculares del Cono Sur (Argentina, Chile, Paraguay, Uruguay, y sur del Brasil)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Solanum section Petota (Solanaceae), which includes the cultivated potato (Solanum tuberosum) and its wild relatives, contains over 150 wild species distributed from the southwestern U.S.A. (38°N) to central Argentina and adjacent Chile (41°S). This catalog includes all species from the Southern Con...

  15. Two new species of the ladybird beetle Hong Ślipiński from Chile (Coleoptera: Coccinellidae: Microweiseinae).

    PubMed

    González, Guillermo; Escalona, Hermes E

    2013-01-01

    The ladybird beetle genus Hong Ślipiński was previously known from a single female specimen from a subtropical forest in South East Queensland, Australia. Hong guerreroi sp. nov. and H. slipinskii sp. nov. from a temperate forests of Central and Southern Chile are described and illustrated. A key for the species of the genus and complementary characters, including the first description of males, are provided. PMID:24758818

  16. Two new species of the ladybird beetle Hong Ślipiński from Chile (Coleoptera: Coccinellidae: Microweiseinae).

    PubMed

    González, Guillermo; Escalona, Hermes E

    2013-01-01

    The ladybird beetle genus Hong Ślipiński was previously known from a single female specimen from a subtropical forest in South East Queensland, Australia. Hong guerreroi sp. nov. and H. slipinskii sp. nov. from a temperate forests of Central and Southern Chile are described and illustrated. A key for the species of the genus and complementary characters, including the first description of males, are provided.

  17. Chile: Una Vision Politica, Economica y Social (Chile: A Political, Economic, and Social View).

    ERIC Educational Resources Information Center

    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…

  18. The Mass Media and Political Socialization: Chile, 1970-2000

    ERIC Educational Resources Information Center

    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…

  19. Honors in Chile: New Engagements in the Higher Education System

    ERIC Educational Resources Information Center

    Skewes, Juan Carlos; Sampaio, Carlos Alberto Cioce; Conway, Frederick J.

    2012-01-01

    Honors programs are rare in Latin America, and in Chile they were unknown before 2003. At the Universidad Austral de Chile, an interdisciplinary group of scholars linked to environmental studies put forward a pilot project for implementing a new experience in higher education. Challenged by an educational environment where (i) apathy and…

  20. World Perspective Case Descriptions on Educational Programs for Adults: Chile.

    ERIC Educational Resources Information Center

    Donoso, Patricio; Gajardo, Marcela

    This document contains two case studies of adult education programs in Chile. Both case studies begin with a "face sheet" on which is recorded basic information about the program and the description. The first case study, prepared by Patricio Donoso, reports on Centro El Canelo de Nos, an inservice center for educators who work with Chile's most…

  1. Critical Perspectives on Adolescent Vocational Guidance in Chile

    ERIC Educational Resources Information Center

    McWhirter, Ellen Hawley; McWhirter, Benedict T.

    2012-01-01

    In this article, the lens of critical psychology is applied to adolescent career development and vocational guidance in Chile. The authors describe and critique the status of adolescent vocational guidance in Chile, the reproduction of extant social inequities in Chilean education, and offer recommendations for enhancing vocational guidance…

  2. 7 CFR 319.56-38 - Citrus from Chile.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 5 2010-01-01 2010-01-01 false Citrus from Chile. 319.56-38 Section 319.56-38... SERVICE, DEPARTMENT OF AGRICULTURE FOREIGN QUARANTINE NOTICES Fruits and Vegetables § 319.56-38 Citrus from Chile. Clementines (Citrus reticulata Blanco var. Clementine), mandarins (Citrus reticulata...

  3. 7 CFR 319.56-38 - Citrus from Chile.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 5 2014-01-01 2014-01-01 false Citrus from Chile. 319.56-38 Section 319.56-38... SERVICE, DEPARTMENT OF AGRICULTURE FOREIGN QUARANTINE NOTICES Fruits and Vegetables § 319.56-38 Citrus from Chile. Clementines (Citrus reticulata Blanco var. Clementine), mandarins (Citrus reticulata...

  4. 7 CFR 319.56-38 - Citrus from Chile.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 5 2011-01-01 2011-01-01 false Citrus from Chile. 319.56-38 Section 319.56-38... SERVICE, DEPARTMENT OF AGRICULTURE FOREIGN QUARANTINE NOTICES Fruits and Vegetables § 319.56-38 Citrus from Chile. Clementines (Citrus reticulata Blanco var. Clementine), mandarins (Citrus reticulata...

  5. 7 CFR 319.56-38 - Citrus from Chile.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 5 2012-01-01 2012-01-01 false Citrus from Chile. 319.56-38 Section 319.56-38... SERVICE, DEPARTMENT OF AGRICULTURE FOREIGN QUARANTINE NOTICES Fruits and Vegetables § 319.56-38 Citrus from Chile. Clementines (Citrus reticulata Blanco var. Clementine), mandarins (Citrus reticulata...

  6. 7 CFR 319.56-38 - Citrus from Chile.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 5 2013-01-01 2013-01-01 false Citrus from Chile. 319.56-38 Section 319.56-38... SERVICE, DEPARTMENT OF AGRICULTURE FOREIGN QUARANTINE NOTICES Fruits and Vegetables § 319.56-38 Citrus from Chile. Clementines (Citrus reticulata Blanco var. Clementine), mandarins (Citrus reticulata...

  7. Education for development under the skies of Chile

    NASA Astrophysics Data System (ADS)

    Scorza, Cecilia; Fischer, Olaf

    2015-03-01

    We report on an educational program initiated in Chile in the year 2010 on the frame of an excellence research and graduate exchange program between the University of Heidelberg and the Pontfica Catlica University in Chile, funded by the German International Exchange Office (DAAD).

  8. FEATURE OF THE 3 MARCH 1985 CHILE EARTHQUAKE - POSSIBLE TERRAIN AMPLIFICATION.

    USGS Publications Warehouse

    Celebi, M.

    1986-01-01

    This paper presents results of site-response experiments performed five months after the M//s equals 7. 8 Central Chile Earthquake of 3 March 1985. The objectives of the experiments performed are to identify amplification due to topography and geology. Topographical amplification at Canal Beagle, a subdivision of Vina del Mar, was hypothesized immediately after the main event, when extensive damage was observed on the ridges of Canal Beagle. Spectral ratios determined from aftershock data obtained from a temporary dense array are used to show that there was substantial amplification of motions at the ridges of Canal Beagle.

  9. HIV ISSUES AND MAPUCHES IN CHILE

    PubMed Central

    Cianelli, Rosina; Ferrer, Lilian; Cabieses, Báltica; Araya, Alejandra; Matsumoto, Cristina; Miner, Sarah

    2015-01-01

    Chile is a country with an incipient HIV epidemic. Just as in other countries, disadvantaged groups in Chile are contributing to the increased incidence of the disease. The Mapuche indigenous population is one such group that has been affected by the spread of HIV. However, no prevention programs are tailored to the culturally specific needs of this community. In recognition of this discrepancy, an academic-community partnership was formed to develop an HIV educational module for a Mapuche community. The module was developed for use as part of an already established health-related program. The aims of the module were to identify perceptions about HIV among Mapuches and present information specific to HIV and its prevention. Focus was placed on cultural sensitivity. The module was carried out in connection with a first-aid course in an attempt to increase effectiveness of the intervention by working jointly with an established community program. Sixteen (16) Mapuches participated voluntarily and demonstrated some knowledge regarding HIV, but they lacked an overall understanding as to how it is transmitted and why prevention strategies are affective. Participants correctly identified sexual contact as a means of transmission, but when asked why, one person stated, “I just know it, I read it.” There were significant barriers to communication within the group, secondary to cultural practices related to age and gender. Major obstacles in controlling HIV are the lack of prevention strategies targeted to disadvantaged groups. The module developed for this intervention was the first effort of the Academic Community Partnership established between the Pontificia Universidad Católica de Chile and the Mapuche group around HIV prevention. Continued collaboration between academia and affected communities as well as incorporating HIV information into established programs are effective strategies for delivering prevention information to disadvantaged populations and for

  10. Familial chondrocalcinosis in the Chiloe Islands, Chile.

    PubMed Central

    Reginato, A J; Hollander, J L; Martinez, V; Valenzuela, F; Schiapachasse, V; Covarrubias, E; Jacobelli, S; Arinoviche, R; Silcox, D; Ruiz, F

    1975-01-01

    Studies about chondrocalcinosis in the Chiloe Islands (Chile) showed the high frequency of the disease there and how most of it is aggregated in a few highly involved families. Pedigrees and the high degree of consanguinity among parents of index cases pointed to a recessive inheritance. The presence of common Caucasian anthropological features of genetic value in the patients and the lack of Indian mixture in three of the involved families, documented back to 1600, suggest a Caucasian origin of the mutation. Biochemical studies of the patients' synovial fluid showed a significant rise in pyrophosphate concentration. Calcium, phosphorus, and alkaline phosphatase concentrations were not different from a control group. PMID:168817

  11. La atencion preescolar en Chile: desafios para la redemocratizacion (Preschool Care in Chile: Challenges for Redemocratization. Discussion Paper No. 13).

    ERIC Educational Resources Information Center

    Filp, Johanna; Undurrage, Consuelo

    This paper examines the current status of programs for preschool children in Chile. Section 1 of the paper provides an overview of the situation of preschool children in Chile. The country's population includes more than 1.6 million children between the ages of 0 and 5 years 11 months, and in urban areas, 18.4 percent of children between the ages…

  12. Estudio del campo ocupacional del traductor en Santiago de Chile (A Study of Opportunities for Professional Translators in Santiago, Chile).

    ERIC Educational Resources Information Center

    Cabrera, Ileana; And Others

    A study of translation as a profession in Chile covered two areas: a diagnostic study of the real need for literary, scientific, and technical translations, and a followup study of graduates of the translation degree program at the Catholic Pontifical University of Chile (Santiago). The analysis considered the relationship between the need for…

  13. Metagenomes of the picoalga Bathycoccus from the Chile coastal upwelling.

    PubMed

    Vaulot, Daniel; Lepère, Cécile; Toulza, Eve; De la Iglesia, Rodrigo; Poulain, Julie; Gaboyer, Frédéric; Moreau, Hervé; Vandepoele, Klaas; Ulloa, Osvaldo; Gavory, Frederick; Piganeau, Gwenael

    2012-01-01

    Among small photosynthetic eukaryotes that play a key role in oceanic food webs, picoplanktonic Mamiellophyceae such as Bathycoccus, Micromonas, and Ostreococcus are particularly important in coastal regions. By using a combination of cell sorting by flow cytometry, whole genome amplification (WGA), and 454 pyrosequencing, we obtained metagenomic data for two natural picophytoplankton populations from the coastal upwelling waters off central Chile. About 60% of the reads of each sample could be mapped to the genome of Bathycoccus strain from the Mediterranean Sea (RCC1105), representing a total of 9 Mbp (sample T142) and 13 Mbp (sample T149) of non-redundant Bathycoccus genome sequences. WGA did not amplify all regions uniformly, resulting in unequal coverage along a given chromosome and between chromosomes. The identity at the DNA level between the metagenomes and the cultured genome was very high (96.3% identical bases for the three larger chromosomes over a 360 kbp alignment). At least two to three different genotypes seemed to be present in each natural sample based on read mapping to Bathycoccus RCC1105 genome.

  14. [Reflections about the historical development of biomedical sciences in Chile and the role of Revista Médica de Chile: an homage on 130-years old].

    PubMed

    Vargas Fernández, Luis

    2002-12-01

    When Revista Médica de Chile turns to be 130 years old, the author reflects about the difficulties that scientific and technological creativity faces in Chile, considering that there was a 70 years gap between its historical origin in Chile compared to developed countries. The scientific progress erases the boundaries between Biomedicine and science and technology. This progress has resulted in an improvement in the quality of scientific publications in Revista Medica de Chile. The editorial work has also contributed to this improvement. Revista Medica de Chile has obtained international recognition and stands in a good position as a medical journal in Latin America and Chile.

  15. Contributions to the mammalogy of Chile

    USGS Publications Warehouse

    Pine, Ronald H.; Miller, Sterling D.; Schamberger, Mel L.

    1979-01-01

    Collections of mammals were made during more than three years of biological investigations in Chile sponsored by the Corporación Nacional Forestal under the aegis of the Peace Corps (Smithsonian Environmental Program). Genera and species hitherto unreported for that country were taken and many useful data concerning distributional patterns of other (mostly little-known) species were gathered. These collections have also proved valuable in better understanding Chilean mammals from a taxonomic point of view and contribute knowledge of the species' natural history. Specimens are to be deposited in the (United States) National Museum of Natural History (USNM) or are to be retained by the Corporación Nacional Forestal, Avda, Bulnes 285, Depto. 401, Santiago. Numbers provided below are field numbers. A final division of specimens between the two institutions has not yet been made. A number of specimens reported here were not taken by Peace Corps personnel but have been obtained by the National Museum of Natural History from other sources. Specimens in the Field Museum of Natural History (FMNH) were used in making comparisons. Some of Fulk's (GWF) specimens are at Texas Tech University. Other are at the Servicio Agricola y Ganadero in Santiago (as are specimens of some introduced species taken by Schamberger). Reise's (DF) are at the Universidad de Chile-Concepción and in his personal collection.

  16. [Liver cirrhosis in Chile: epidemiologic considerations].

    PubMed

    Medina, E; Kaempffer, A M

    1993-11-01

    Liver cirrhosis is an important public health problem in Chile, accounting for 5% of all deaths, proportion that has increased 24 fold in the last 60 years. Chile has the highest death rate for cirrhosis in America and the second highest in the world, after Hungary. The risk of death and hospitalization for cirrhosis has increased significantly between 1950 and 1970, stabilizing thereafter in values near to 50 hospitalizations and 30 deaths/year per 100,000 inhabitants. The risk for cirrhosis is higher among men and increases with age. Among people between 35 and 60 years of age, cirrhosis is the first or second cause of death and the third among those aged 60 to 69 years. The age of patients hospitalized for cirrhosis has increased from 42.7 years in 1950 to 55.5 in 1990. Among women, cirrhosis appears at older ages than in men. Mortality rates vary in the different regions of the country and range from 55 in Concepcion and Talcahuano to 8 per 100,000 inhabitants in Coquimbo. The certainty of Chilean information on cirrhosis and the evidences associating cirrhosis to alcohol consumption are discussed, being prominent the significant association between annual death rates for cirrhosis and wine production. PMID:8191144

  17. Stakeholder participation within the public environmental system in Chile: major gaps between theory and practice.

    PubMed

    Lostarnau, Carla; Oyarzún, Jorge; Maturana, Hugo; Soto, Guido; Señoret, Michelle; Soto, Manuel; Rötting, Tobias S; Amezaga, Jaime M; Oyarzún, Ricardo

    2011-10-01

    The main objective of this paper is to present a critical analysis of the stakeholder participation process within the Environmental Impact Assessment System in Chile, after ca. 14 years of being enforced. This analysis is sustained by the description and analysis of the stakeholder participation possibilities in a representative rural area of North-Central Chile. The Environmental Basis Act 19300, enacted in 1994, considers the participation of the local community in the environmental impact assessment of new projects. However, this possibility is very limited and difficult to exert, often resulting in frustration for the participants. This is due to a number of reasons, such as the imbalance of resources and knowledge among the majority of participating communities and project proponents, the complexity and administrative and legal constraints to participation, and the dominant interest of the Central Government in approving investments, specifically in energy and natural resources related projects, which generate wealth and jobs. Also, the State's rush to develop Internet-based communication and management systems has built a barrier for poor, traditional communities. This factor is clearly reflected in the case study considered. Results show that there is generally a significant lack of knowledge about institutions and participation tools. From this base, we intend to raise concern on these selected aspects that could be addressed to improve the effectiveness of the existing framework, both in Chile and in other developing countries, where immature environmental impact assessment and public management systems face similar pressures in relation to the sustainable use of their natural resources. Finally, some basic steps are proposed in order to make the community participation an effective tool for sustainable development.

  18. Stakeholder participation within the public environmental system in Chile: major gaps between theory and practice.

    PubMed

    Lostarnau, Carla; Oyarzún, Jorge; Maturana, Hugo; Soto, Guido; Señoret, Michelle; Soto, Manuel; Rötting, Tobias S; Amezaga, Jaime M; Oyarzún, Ricardo

    2011-10-01

    The main objective of this paper is to present a critical analysis of the stakeholder participation process within the Environmental Impact Assessment System in Chile, after ca. 14 years of being enforced. This analysis is sustained by the description and analysis of the stakeholder participation possibilities in a representative rural area of North-Central Chile. The Environmental Basis Act 19300, enacted in 1994, considers the participation of the local community in the environmental impact assessment of new projects. However, this possibility is very limited and difficult to exert, often resulting in frustration for the participants. This is due to a number of reasons, such as the imbalance of resources and knowledge among the majority of participating communities and project proponents, the complexity and administrative and legal constraints to participation, and the dominant interest of the Central Government in approving investments, specifically in energy and natural resources related projects, which generate wealth and jobs. Also, the State's rush to develop Internet-based communication and management systems has built a barrier for poor, traditional communities. This factor is clearly reflected in the case study considered. Results show that there is generally a significant lack of knowledge about institutions and participation tools. From this base, we intend to raise concern on these selected aspects that could be addressed to improve the effectiveness of the existing framework, both in Chile and in other developing countries, where immature environmental impact assessment and public management systems face similar pressures in relation to the sustainable use of their natural resources. Finally, some basic steps are proposed in order to make the community participation an effective tool for sustainable development. PMID:21641109

  19. Shelfal sediment transport by undercurrents forces turbidity current activity during high sea level, Chile continental margin

    NASA Astrophysics Data System (ADS)

    Bernhardt, Anne; Hebbeln, Dierk; Regenberg, Marcus; Lückge, Andreas; Strecker, Manfred. R.

    2016-04-01

    Understanding the links between terrigenous sediment supply and marine transport and depositional processes along tectonically active margins is essential to decipher turbidite successions as potential archives of climatic and seismic forcings and to comprehend timing and quantity of marine clastic deposition. Sequence stratigraphic models predict coarse-grained terrigenous sediment delivery to deep-marine sites mainly during sea-level fall and lowstand. Marine clastic deposition during periods of transgression and highstand has been attributed to the continued geomorphic connectivity between terrestrial sediment sources and marine sinks (e.g., rivers connected to submarine canyons) often facilitated by narrow shelves, high sediment supply causing delta migration to the shelf edge, and/or abrupt increases in sediment supply due to climatic variability or catastrophic events. To decipher the controls on Holocene highstand turbidite deposition, we analyzed twelve sediment cores of spatially disparate, coeval Holocene turbidite systems along the Chile margin (29-40°S) with changing climatic and geomorphic characteristics but uniform changes of sea level. Intraslope basins in north-central Chile (29-33°S) offshore a narrow to absent shelf record a shut-off of turbidite activity during the Holocene. In contrast, core sites in south-central Chile (36-40°S) offshore a wide continental shelf have repeatedly experienced turbidite deposition during sea-level highstand conditions, even though most of the depocenters are not connected via canyons to sediment sources. The interplay of stable high sediment supply related to strong onshore precipitation in combination with a wide shelf, over which undercurrents move sediment towards the shelf edge, appears to control Holocene turbidite sedimentation and sediment export to the deep sea.

  20. ESO and Chile: 10 Years of Productive Scientific Collaboration

    NASA Astrophysics Data System (ADS)

    2006-06-01

    ESO and the Government of Chile launched today the book "10 Years Exploring the Universe", written by the beneficiaries of the ESO-Chile Joint Committee. This annual fund provides grants for individual Chilean scientists, research infrastructures, scientific congresses, workshops for science teachers and astronomy outreach programmes for the public. In a ceremony held in Santiago on 19 June 2006, the European Organisation for Astronomical Research in the Southern Hemisphere (ESO) and the Chilean Ministry of Foreign Affairs marked the 10th Anniversary of the Supplementary Agreement, which granted to Chilean astronomers up to 10 percent of the total observing time on ESO telescopes. This agreement also established an annual fund for the development of astronomy, managed by the so-called "ESO-Chile Joint Committee". ESO PR Photo 21/06 ESO PR Photo 21/06 Ten Years ESO-Chile Agreement Ceremony The celebration event was hosted by ESO Director General, Dr. Catherine Cesarsky, and the Director of Special Policy for the Chilean Ministry of Foreign Affairs, Ambassador Luis Winter. "ESO's commitment is, and always will be, to promote astronomy and scientific knowledge in the country hosting our observatories", said ESO Director General, Dr. Catherine Cesarsky. "We hope Chile and Europe will continue with great achievements in this fascinating joint adventure, the exploration of the universe." On behalf of the Government of Chile, Ambassador Luis Winter outlined the historical importance of the Supplementary Agreement, ratified by the Chilean Congress in 1996. "Such is the magnitude of ESO-Chile Joint Committee that, only in 2005, this annual fund represented 8 percent of all financing sources for Chilean astronomy, including those from Government and universities", Ambassador Winter said. The ESO Representative and Head of Science in Chile, Dr. Felix Mirabel, and the appointed Chilean astronomer for the ESO-Chile Joint Committee, Dr. Leonardo Bronfman, also took part in the

  1. Checklist, diversity and distribution of testate amoebae in Chile.

    PubMed

    Fernández, Leonardo D; Lara, Enrique; Mitchell, Edward A D

    2015-10-01

    Bringing together more than 170 years of data, this study represents the first attempt to construct a species checklist and analyze the diversity and distribution of testate amoebae in Chile, a country that encompasses the southwestern region of South America, countless islands and part of the Antarctic. In Chile, known diversity includes 416 testate amoeba taxa (64 genera, 352 infrageneric taxa), 24 of which are here reported for the first time. Species-accumulation plots show that in Chile, the number of testate amoeba species reported has been continually increasing since the mid-19th century without leveling off. Testate amoebae have been recorded in 37 different habitats, though they are more diverse in peatlands and rainforest soils. Only 11% of species are widespread in continental Chile, while the remaining 89% of the species exhibit medium or short latitudinal distribution ranges. Also, species composition of insular Chile and the Chilean Antarctic territory is a depauperated subset of that found in continental Chile. Nearly, the 10% of the species reported here are endemic to Chile and many of them are distributed only within the so-called Chilean biodiversity hotspot (ca. 25° S-47° S). These findings are here thoroughly discussed in a biogeographical and evolutionary context. PMID:26340665

  2. [Ecology and health in Chile: present and future development].

    PubMed

    Oyarzún, M

    1997-09-01

    In response to the progressive environmental deterioration, the Ecological Society of America has made a proposal, called "Sustainable Biosphere Initiative", to do research, teaching and decision making processes on biodiversity, global change and the effects of human activities on environment. The goal of appropriate environmental protection and welfare for mankind includes health and quality of life. Presently, Chile faces a number of environmental problems such as pollution, excessive urban growth, loss of agricultural areas, disposal of solid waste and species extinction. The lack of education and information in Chile, on these problems, is worrisome. The role of universities to overcome this deficit should be crucial in the future sustainable development of Chile.

  3. Tropospheric anomalies following the 2010 Mw=8.8 Chile earthquake from GPS observations

    NASA Astrophysics Data System (ADS)

    Gurbuz, Gokhan; Jin, Shuanggen

    2016-07-01

    The Mw=8.8 Maule earthquake occured on 27 February 2010 near the coast of central Chile, which killed more than 500 people and caused large economic losses. Meanwhile, the earthquake triggered a tsunami with devastating several coastal towns in south-central Chile and damaging the port at Talcahuano. Several geodetic observations data and methods were used to investigate pre-seismic ionospheric disturbances and co-seismic crustal deformations on this eartquake, such as InSAR and GPS measurements. However, the precursor and detailed rupture properties of this earthquake are still not clear. In this study tropospheric anomalies following the Mw=8.8 Maule earthquake are investigated using zenith tropospheric delay (ZTD) computed from GPS observations. Results show tropospheric anomalies during and after the mainchock at CONZ that is the closest GPS station to the epicenter and VALP station that is close to the fault rupture. The possible mechanism of seismic-tropospheric disturbances is discussed, which will be further studied in near future.

  4. Epidemiology of Vibrio parahaemolyticus outbreaks, southern Chile.

    PubMed

    Harth, Erika; Matsuda, Luis; Hernández, Cristina; Rioseco, Maria L; Romero, Jaime; González-Escalona, Narjol; Martínez-Urtaza, Jaime; Espejo, Romilio T

    2009-02-01

    Disease outbreaks caused by Vibrio parahaemolyticus in Puerto Montt, Chile, began in 2004 and reached a peak in 2005 at 3,600 clinical cases. Until 2006, every analyzed case was caused by the serovar O3:K6 pandemic strain. In the summer of 2007, only 475 cases were reported; 73% corresponded to the pandemic strain. This decrease was associated with a change in serotype of many pandemic isolates to O3:K59 and the emergence of new clinical strains. One of these strains, associated with 11% of the cases, was genotypically different from the pandemic strain but contained genes that were identical to those found on its pathogenicity island. These findings suggest that pathogenicity-related genes were laterally transferred from the pandemic strain to one of the different V. parahaemolyticus groups comprising the diverse and shifting bacterial population in shellfish in this region. PMID:19193258

  5. Privatization And Vouchers In Colombia And Chile

    NASA Astrophysics Data System (ADS)

    Arenas, Alberto

    2004-07-01

    The voucher model of financing schooling is becoming increasingly common throughout Latin America, with at least 12 countries using vouchers or voucher-like schemes. The present study focuses on the voucher models of Colombia and Chile, which have the most extensive programs of this type and those of the longest standing in the region. Using empirical evidence, the author compares the two models along four evaluative dimensions: educational quality, segregation, choice and socialization. After weighing the successes and weaknesses of each system, he concludes that, among other characteristics, the most effective and equitable voucher model features: (a) a flexible interpretation of educational quality; (b) financial grants which target solely the poor; (c) vouchers which cover the entire cost of tuition; (d) open enrolment at participating schools; (e) the participation of both secular and religious private schools; (f) accessible and meaningful information to parents; and (g) strong systems of accountability.

  6. Three halls for music performance in Chile

    NASA Astrophysics Data System (ADS)

    Delannoy, Jaime; Heuffemann, Carolina; Ramirez, Daniel; Galvez, Fernando

    2002-11-01

    The primary purpose of this work was to investigate about the present acoustic conditions of used architectonic spaces in Santiago of Chile for orchestras of classic music performance. The studied halls were three: Aula Magna Universidad de Santiago, Teatro Municipal de Nunoa, and Teatro Baquedano. The used methodology was based on studies made by L. Beranek, M. Barron, among others, in concert halls worldwide. As it guides, for the measurement procedure, physical parameters RT, EDT, C50, C80, LF, BR, G, U50 were evaluated according to norm ISO 3382. On the other hand, it has been defined, to proposal way, a questionnaire of subjective valuation directed to musicians, specialized conductors, and listeners.

  7. Human pseudoterranovosis, an emerging infection in Chile.

    PubMed

    Torres, P; Jercic, M I; Weitz, J C; Dobrew, E K; Mercado, R A

    2007-04-01

    Fifteen cases of human pseudoterranovosis are reported for Chile, representing an emerging parasitic infection in this country caused by larvae of the nematode Pseudoterranova sp. Our observations also included an outbreak of pseudoterranovosis in 3 of 4 individuals who shared the same raw fish dish (cebiche). Most of the cases occurred in adult patients. The main source of infection was from consumption raw or fried marine fish, including hakes (Merluccius australis or Merlucciuts gayi), pomfret (Brama australis), Inca scad (Trachurus murphvi), and corvina (Cilus gilberti). Seasonal distribution showed most of the cases to occur in fall and spring. Parasite larvae were isolated from the mouths of most of the patients after they reported a pharyngeal tickling sensation, coughing, vomiting, or a foreign body in the mouth or throat.

  8. Human pseudoterranovosis, an emerging infection in Chile.

    PubMed

    Torres, P; Jercic, M I; Weitz, J C; Dobrew, E K; Mercado, R A

    2007-04-01

    Fifteen cases of human pseudoterranovosis are reported for Chile, representing an emerging parasitic infection in this country caused by larvae of the nematode Pseudoterranova sp. Our observations also included an outbreak of pseudoterranovosis in 3 of 4 individuals who shared the same raw fish dish (cebiche). Most of the cases occurred in adult patients. The main source of infection was from consumption raw or fried marine fish, including hakes (Merluccius australis or Merlucciuts gayi), pomfret (Brama australis), Inca scad (Trachurus murphvi), and corvina (Cilus gilberti). Seasonal distribution showed most of the cases to occur in fall and spring. Parasite larvae were isolated from the mouths of most of the patients after they reported a pharyngeal tickling sensation, coughing, vomiting, or a foreign body in the mouth or throat. PMID:17539437

  9. The 2015 Chile-U.S. Astronomy Education Outreach Summit in Chile

    NASA Astrophysics Data System (ADS)

    Preston, Sandra Lee; Arnett, Dinah; Hardy, Eduardo; Cabezón, Sergio; Spuck, Tim; Fields, Mary Sue; Smith, R. Chris

    2015-08-01

    The first Chile-U.S. Astronomy Education Outreach Summit occurred March 22-28, 2015. The Summit was organized and supported by the U.S. Embassy in Chile, Associated Universities Inc., Association of Universities for Research in Astronomy, the Carnegie Institution for Science, the Image of Chile Foundation, the National Science Foundation, and La Comisión Nacional de Investigación Científica y Tecnológica. The Summit brought together a team of leading experts and officials from Chile and the U.S. to share best practices in astronomy education and outreach. In addition, Summit participants discussed enhancing existing partnerships, and building new collaborations between U.S. Observatories and astronomy education outreach leaders in Chile.The Summit was an exciting and intense week of work and travel. Discussions opened in Santiago on March 22 with a variety of astronomy education and public outreach work sessions, a public forum, and on March 23 the U.S. Embassy sponsored a Star Party. On Tuesday, March 24, the Summit moved to San Pedro de Atacama, where activities included work sessions, a visit to the Atacama Large Millimeter/Submillimeter Array telescope facilities, and a second public forum. From San Pedro, the team traveled to La Serena for additional work sessions, visits to Gemini and Cerro Tololo, a third public forum, and the closing session. At each stop, authorities and the broader community were invited to participate and provide valuable input on the current state, and the future, of astronomy education and public outreach.Following the Summit a core working committee has continued meeting to draft a “roadmap document” based on findings from the Summit. This document will help to identify potential gaps in astronomy outreach efforts, and how the U.S. facilities and Chilean institutions might work together strategically to address these needs. The first draft of this “roadmap document” will be made available for comment in both Spanish and

  10. Some similar seismic characteristics of the 2014 Iquique and 2015 Illapel earthquakes in Chile

    NASA Astrophysics Data System (ADS)

    Ruiz, Sergio; Klein, Emilie; del Campo, Francisco; Rivera, Efrain; Metois, Marianne; León, Sergio; Fuenzalida, Amaya; Poli, Piero; Vigny, Christophe; Baez, Juan Carlos; Maksymowicz, Andrei; Ruiz, Javier; Grandin, Raphael; Vargas, Gabriel; Leyton, Felipe; Madariaga, Raúl; Fleitout, Luce

    2016-04-01

    The 2014 Iquique Mw 8.2, and 2015 Illapel Mw 8.3 earthquakes occurred inside of the mega-rupture zones of 1877 in Northern Chile and 1730 in Central Chile, respectively. 1877 and 1730 are the two largest megathrust events that probably controls the seismic cycle of these two zones, recent paleo-seismological studies propose recurrence intervals between ~200 and ~650 years for these giant earthquakes. The two 2014 and 2015 events were very well recorded by large permanent broadband and strong motion networks, temporary broadband digital stations, high rate GPS instruments and InSAR images. With this large dataset we attempt to understand the processes of interaction between slow and fast deformation in these zones, which produced these events of magnitude Mw~8.0. We study the upper plate deformation before both events using the continuous time displacement of GPS antennas. Both earthquakes show precursory phases: Iquique was preceded by a slow slip event and Illapel was preceded by a deep transient slow slip produced by postseismic deformation due to the Mw 8.8 2010 Maule mega-earthquake. On the other hand, a remarkable feature of the Iquique and Illapel coseismic ruptures was their nucleation processes. Both were preceded in their first 20 seconds by small events that released a tiny fraction of the total seismic energy. The largest release of seismic energy was generated at the end of these precursory ruptures. We can interpret this process in terms of a simple asperity model, where the boundaries of the rupture are controlled by the plate interface. The areas surrounding both rupture zones were weakly coupled and a presented concentration of swarms and repeating events. Finally, we relocated and computed moment tensors of the events of magnitude Mw ≥ 4.5. Most of the fore- and after -shocks of both earthquakes are interplate events surrounding the rupture zones of the main events. However, in the Iquique earthquake these events are located in a band of about 50

  11. Household treatment for "chile burns" of the hands.

    PubMed

    Jones, L A; Tandberg, D; Troutman, W G

    1987-01-01

    In New Mexico, chile peppers (Capsicum annum) are prepared by roasting and manually removing the skin from the fruit. Peeling is often done barehanded and may cause prolonged burning pain, irritation, and erythema but not vesication. In a survey of elderly Hispanic women, treatment with oils or cool tap water were frequently used home remedies. Twenty female subjects immersed their hands in a standardized slurry of green chile for 40 minutes, afterwards one hand was placed in cool tap water and the other in vegetable oil for a total of 75 minutes. Pain was scored using a visual analog scale while the hands were immersed in the chile slurry, test baths, and after drying. The difference in pain score was calculated for each subject. Analysis was by pooled regression. Cool tap water immersion initially provided more relief while vegetable oil provided better long-term relief from the pain of "chile burns".

  12. Conducting a Teacher Professional Development Program in Chile

    NASA Astrophysics Data System (ADS)

    Crosby, G. A.; Crosby, J. L.

    1998-07-01

    In January 1998, we directed a two-week laboratory-oriented teacher professional development program, "Curso Experimental de Quimica", for thirty-six high school chemistry teachers in Santiago, Chile. Participants earned a certificate of completion from the University of Chile. Our involvement began in 1996, when we presented a plenary lecture in science education at the XXII Latin American Congress of Chemistry in Concepcion, Chile. In that address, we discussed the philosophy and the operation of the Master of Arts in Chemistry Program1 that we were running in the State of Washington. The response to the presentation was enthusiastic, and eventually Hugo Zunino, the Dean of the School of Chemical and Pharmaceutical Sciences at the University of Chile, visited us in Pullman to explore the idea of involving us in a teacher development initiative in Santiago.

  13. Tectonic and morphosedimentary features of the 2010 Chile earthquake and tsunami in the Arauco Gulf and Mataquito River (Central Chile)

    NASA Astrophysics Data System (ADS)

    Lario, J.; Zazo, C.; Goy, J. L.

    2016-08-01

    Effects of the 2010 Chilean earthquake and tsunami were evaluated at coastal sites between two zones of different coseismic deformations. Land deformation, run-up, inundation extent and deposit extent and thickness were measured in the field, providing insights into the processes and morphological changes associated with tsunami inundation and backwash. Three to five waves, of up to 10 m height, deposited several related layers along the coast, the thickness of these sandy deposits does not exceed 80 cm, and is generally less than 30 cm. Coseismic deformation measured by means of bio- and geomorphic markers agrees well both with model deformation and measured GPS. There is no relationship between the run-up height and the trend of coseismic deformation (uplift or subsidence), mainly because the effects of the tsunami were influenced locally by offshore bathymetry and coastal morphology.

  14. New records to Chile of the Family Paraonidae (Annelida: Polychaeta)

    NASA Astrophysics Data System (ADS)

    Montiel, Américo; Hilbig, Brigitte; Rozbaczylo, Nicolás

    2002-06-01

    The Paraonidae are a polychaete family of small body size which have not been reported for Chile until recently. Mainly due to improved sample-processing methods, research campaigns carried out in 1994 and 1996 on three areas off southern Chile have yielded numerous records. Several species proved to be new to the Chilean polychaete fauna, including species that have been known previously only from Antarctic areas. These new records and range extensions are reported in this paper.

  15. The Effects on Tsunami Hazard Assessment in Chile of Assuming Earthquake Scenarios with Spatially Uniform Slip

    NASA Astrophysics Data System (ADS)

    Carvajal, Matías; Gubler, Alejandra

    2016-06-01

    We investigated the effect that along-dip slip distribution has on the near-shore tsunami amplitudes and on coastal land-level changes in the region of central Chile (29°-37°S). Here and all along the Chilean megathrust, the seismogenic zone extends beneath dry land, and thus, tsunami generation and propagation is limited to its seaward portion, where the sensitivity of the initial tsunami waveform to dislocation model inputs, such as slip distribution, is greater. We considered four distributions of earthquake slip in the dip direction, including a spatially uniform slip source and three others with typical bell-shaped slip patterns that differ in the depth range of slip concentration. We found that a uniform slip scenario predicts much lower tsunami amplitudes and generally less coastal subsidence than scenarios that assume bell-shaped distributions of slip. Although the finding that uniform slip scenarios underestimate tsunami amplitudes is not new, it has been largely ignored for tsunami hazard assessment in Chile. Our simulations results also suggest that uniform slip scenarios tend to predict later arrival times of the leading wave than bell-shaped sources. The time occurrence of the largest wave at a specific site is also dependent on how the slip is distributed in the dip direction; however, other factors, such as local bathymetric configurations and standing edge waves, are also expected to play a role. Arrival time differences are especially critical in Chile, where tsunamis arrive earlier than elsewhere. We believe that the results of this study will be useful to both public and private organizations for mapping tsunami hazard in coastal areas along the Chilean coast, and, therefore, help reduce the risk of loss and damage caused by future tsunamis.

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

    NASA Astrophysics Data System (ADS)

    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

  17. Chile's dilemma: how to reinsert scientists trained abroad.

    PubMed

    Nunez-Parra, Alexia; Ramos, Maria-Paz

    2014-01-01

    Chile is recognized worldwide as an emergent economy, with a great power in natural resource exploitation. Nonetheless, despite being one of the most developed countries in Latin America, Chile imports most of the knowledge and technology necessary to drive innovation in the country. The tight budget that the Chilean government assigned to research and development and the absence of a long-term scientific agenda contributed to a limited supply of scientists over the years. In an effort to reverse this scenario, Chile has created several fellowships, such as the Becas Chile Program (BCP) to encourage new generations to pursue graduate studies to ultimately advance research and development in situ. More than 6000 fellows are now being trained abroad, accumulating an incredible potential to transform the Chilean scientific environment as we know it.  Chile now faces a greater challenge: it has to offer infrastructure and job openings to the highly skilled professionals in whom it invested. Unfortunately no clear public policies to address this situation have been developed, partially due to the lack of a dedicated institution, such as a Ministry for Science and Technology which could focalize the necessary efforts to promote such policies. Therefore, in the meantime, Chilean scientist have been motivated to create different organizations, such as, Mas Ciencia para Chile and Nexos Chile-USA, to promote constructive discussion of the policies that could be implemented to improve the Chilean scientific situation. We hope that these and other organizations have a real impact on the generation of scientific guidelines that will finally contribute to the development of the country. PMID:25309739

  18. Chile's dilemma: how to reinsert scientists trained abroad.

    PubMed

    Nunez-Parra, Alexia; Ramos, Maria-Paz

    2014-01-01

    Chile is recognized worldwide as an emergent economy, with a great power in natural resource exploitation. Nonetheless, despite being one of the most developed countries in Latin America, Chile imports most of the knowledge and technology necessary to drive innovation in the country. The tight budget that the Chilean government assigned to research and development and the absence of a long-term scientific agenda contributed to a limited supply of scientists over the years. In an effort to reverse this scenario, Chile has created several fellowships, such as the Becas Chile Program (BCP) to encourage new generations to pursue graduate studies to ultimately advance research and development in situ. More than 6000 fellows are now being trained abroad, accumulating an incredible potential to transform the Chilean scientific environment as we know it.  Chile now faces a greater challenge: it has to offer infrastructure and job openings to the highly skilled professionals in whom it invested. Unfortunately no clear public policies to address this situation have been developed, partially due to the lack of a dedicated institution, such as a Ministry for Science and Technology which could focalize the necessary efforts to promote such policies. Therefore, in the meantime, Chilean scientist have been motivated to create different organizations, such as, Mas Ciencia para Chile and Nexos Chile-USA, to promote constructive discussion of the policies that could be implemented to improve the Chilean scientific situation. We hope that these and other organizations have a real impact on the generation of scientific guidelines that will finally contribute to the development of the country.

  19. Microtextural analysis of quartz grains of tsunami and non-tsunami deposits - A case study from Tirúa (Chile)

    NASA Astrophysics Data System (ADS)

    Bellanova, Piero; Bahlburg, Heinrich; Nentwig, Vanessa; Spiske, Michaela

    2016-08-01

    In order to estimate the tsunami hazard it is essential to reliably identify and differentiate tsunami deposits from other high-energy events like storms. Recently, the microtextural analysis of quartz grain surfaces was introduced as a method to differentiate between tsunami and other deposits. Using tsunami deposits sampled from a bank profile of the Tirúa river (central Chile), an area that was significantly affected by the 2010 and 1960 Chile tsunamis, we tested the microtextural analysis method for its capability to identify tsunami deposits. A total of 815 quartz grain surfaces of two tsunami layers, two non-tsunami marsh sediment samples, and three reference samples from nearby beach, dune and river were analyzed using scanning electron microscopy (SEM). We grouped the detected microtexture features into five microtextural families: angularity, fresh surfaces, percussion marks, adhering particles and dissolution features. Both the tsunami deposits and reference samples reveal high numbers of fresh surfaces and percussion marks. Thus, there are no statistically significant differences between tsunami, beach, dune and river deposits in characteristics and abundances in all microtextural families. Our study indicates that the microtextural analysis of quartz grains may not be a suitable method to identify tsunami deposits in Tirúa (Chile), due to local factors such as high numbers of inherited microtextures and the possible effects of the high amount of heavy minerals.

  20. [Foot and mouth disease in human beings. A human case in Chile].

    PubMed

    Berríos E, Patricio

    2007-04-01

    Foot and mouth disease (FMD) of cattle can cause a significant economic burden and is thus for one of the most feared of cattle disease. FMD is endemic in South America, Africa, Asia and parts of Europe and it is characterized by vesicles in different locations, mainly mouth, feet and teats leading to severe animal weakness. Currently most countries refuse to import livestock and livestock products from FMD areas. North and Central America are currently free of FMD and Chile is free of FMD from 1987. Approximately 40 cases of human infection with FMD virus have been reported, mostly in Europe, and confirmed by virus isolation and the detection of a specific immune response. We discuss the case of a human infection with FMD virus occurred in Chile in 1961 and other relevant cases reported. FMD does not currently present a threat to public health. Even though the FMD virus has the potential to mutate rapidly and emerge as a significant human zoonosis; the rarity of the disease in humans despite a long history of close contact with FMD infected animals suggests that the risk is highly improbable. Then FMD should not be managed as a zoonosis.

  1. Gastrointestinal and external parasites of Enicognathus ferrugineus and Enicognathus leptorhynchus (Aves, Psittacidae) in Chile.

    PubMed

    Valdebenito, José Osvaldo; Moreno, Lucila; Landaeta-Aqueveque, Carlos; Kinsella, John Mike; Mironov, Sergey; Cicchino, Armando; Troncoso, Ignacio; González-Acuña, Daniel

    2015-01-01

    Parasite species are important components of biodiversity, as they provide valuable information about host health, evolutionary relationships, population structures, trophic interactions, the existence of environmental stresses, and climatic conditions. With the aim of describing the parasites associated with parrots of the genus Enicognathus Gray 1840 from central Chile, thirteen austral parakeets, Enicognathus ferrugineus, and five slender-billed parakeets, E. leptorhynchus, were examined between September 2007 and March 2014. The prevalence of ectoparasites and endoparasites was 88.9% and 22.2%, respectively. On eleven of the E. ferrugineus (84.6%) analyzed, and on all of the E. leptorhynchus analyzed (100%), five feather mite species (Pararalichus hastifolia, Genoprotolichus major, Protonyssus sp., Fainalges sp., and Eurydiscalges sp.) were collected. On ten E. ferrugineus (76.9%) and two E. leptorhynchus (40%), the chewing lice Heteromenopon macrurum, Psittacobrossus patagoni, and Paragoniocotes enicognathidis were collected. The nematode Capillaria plagiaticia was collected from three E. ferrugineus (23.1%), and the nematode Ascaridia hermaphrodita was found in one E. leptorhynchus (20%). The presence of C. plagiaticia, Protonyssus sp., Fainalges sp., and Eurydiscalges sp. from the two Enicognathus spp. are new records for Chile and represent new parasite-host associations. PMID:26648008

  2. GPS-derived interseismic coupling on the subduction and seismic hazards in the Atacama region, Chile

    NASA Astrophysics Data System (ADS)

    Métois, M.; Vigny, C.; Socquet, A.; Delorme, A.; Morvan, S.; Ortega, I.; Valderas-Bermejo, C.-M.

    2014-02-01

    The Atacama region (between 29°S and 25°S) is located in the North-Central area of Chile, a tectonically complex transition area between North and Central Chile. Deformation in Atacama is due mainly to elastic loading on the subduction interface but also to diffuse shortening in the Sierras Pampeanas, Argentina. The seismicity of the subduction is complex in this region: seismic swarms often occur, moderate (Mw ˜ 6) to large (Mw ˜ 7) earthquakes occur repeatedly and finally, megathrust earthquakes of magnitudes significantly larger than 8 occur once in a while, the last one being in 1922-almost a century ago. We use new GPS data we collected in the Atacama region between 2008 and 2012 to complete and densify existing data we acquired since 2004 in North-Central Chile. These new data allow to quantify the motion of the Andean sliver and assess the kinematic coupling on the subduction interface at these latitudes. We find that only 7 per cent of the whole convergence motion is taken up by an eastward rotation of the rigid sliver. A large part of the remaining 93 per cent (approximately 6 cm yr-1) gives way to accumulation of elastic deformation in the upper plate, due to locking on the plate interface. This accumulation shows important along-strike and along-dip variations, interpreted in terms of variable coupling which we correlate with seismicity. We identify two areas of low coupling near the `La Serena' (30°S) and `Baranquilla' (27.5°S) bays. Both are correlated with the subduction of singular bathymetric features and seem to stop the propagation of large seismic ruptures. These zones are also seismic swarm prone areas, which seem to occur rather on their edges. These low coupling areas separate two seismic segments where coupling is high: the Atacama segment (˜100 km long between 29°S and 28°S) and the Chañaral segment (˜200 km long between 27°S and 25°S). Should they rupture alone, these segments are sufficiently coupled and apparently since long

  3. [Eating habits and subjective well-being among university students in southern Chile].

    PubMed

    Schnettler, Berta; Denegri, Marianela; Miranda, Horacio; Sepúlveda, José; Orellana, Ligia; Paiva, Galo; Grunert, Klaus G

    2013-11-01

    Objetivo: Distinguir tipologías de estudiantes universitarios en el sur de Chile, en base a su nivel de satisfacción con la vida y la alimentación, y caracterizarlas según sus hábitos alimentarios dentro y fuera del lugar de residencia, aspectos asociados a la salud y características demográficas. Material y método: Se aplicó un cuestionario estructurado a una muestra no probabilística de 347 estudiantes de la Universidad de La Frontera, Temuco-Chile. El instrumento de recogida de información incluyó las escalas SWLS (Satisfaction with Life Scale), SWFL (Satisfaction with Food-related Life) y el ICVRS (Índice de calidad de vida relativo a la salud). Se consultaron los hábitos de consumo de alimentos dentro y fuera del lugar de residencia, el peso y estatura aproximada y, variables de clasificación demográfica. Resultados: Mediante análisis clúster se distinguieron tres tipologías de estudiantes con diferencias significativas en los puntajes de la SWLS y SWFL. Las tipologías difirieron en el número de días afectados por problemas de salud emocional, clasificación de su estado nutricional (IMC), auto percepción de su estado de salud, importancia de la alimentación para el bienestar personal, lugar de residencia durante el periodo de estudios, frecuencia de alimentación en el lugar donde vive y frecuencia de comidas a deshora. Conclusiones: La posibilidad de vivir con los padres durante el periodo de estudios universitarios se asocia con mejores hábitos de alimentación, mejor salud emocional y auto percepción de la salud, menor prevalencia de sobre peso y obesidad y, con una mayor satisfacción con la vida y la alimentación.

  4. Predecessors of the giant 1960 Chile earthquake

    USGS Publications Warehouse

    Cisternas, M.; Atwater, B.F.; Torrejon, F.; Sawai, Y.; Machuca, G.; Lagos, M.; Eipert, A.; Youlton, C.; Salgado, I.; Kamataki, T.; Shishikura, M.; Rajendran, C.P.; Malik, J.K.; Rizal, Y.; Husni, M.

    2005-01-01

    It is commonly thought that the longer the time since last earthquake, the larger the next earthquake's slip will be. But this logical predictor of earthquake size, unsuccessful for large earthquakes on a strike-slip fault, fails also with the giant 1960 Chile earthquake of magnitude 9.5 (ref. 3). Although the time since the preceding earthquake spanned 123 years (refs 4, 5), the estimated slip in 1960, which occurred on a fault between the Nazca and South American tectonic plates, equalled 250-350 years' worth of the plate motion. Thus the average interval between such giant earthquakes on this fault should span several centuries. Here we present evidence that such long intervals were indeed typical of the last two millennia. We use buried soils and sand layers as records of tectonic subsidence and tsunami inundation at an estuary midway along the 1960 rupture. In these records, the 1960 earthquake ended a recurrence interval that had begun almost four centuries before, with an earthquake documented by Spanish conquistadors in 1575. Two later earthquakes, in 1737 and 1837, produced little if any subsidence or tsunami at the estuary and they therefore probably left the fault partly loaded with accumulated plate motion that the 1960 earthquake then expended. ?? 2005 Nature Publishing Group.

  5. Predecessors of the giant 1960 Chile earthquake.

    PubMed

    Cisternas, Marco; Atwater, Brian F; Torrejón, Fernando; Sawai, Yuki; Machuca, Gonzalo; Lagos, Marcelo; Eipert, Annaliese; Youlton, Cristián; Salgado, Ignacio; Kamataki, Takanobu; Shishikura, Masanobu; Rajendran, C P; Malik, Javed K; Rizal, Yan; Husni, Muhammad

    2005-09-15

    It is commonly thought that the longer the time since last earthquake, the larger the next earthquake's slip will be. But this logical predictor of earthquake size, unsuccessful for large earthquakes on a strike-slip fault, fails also with the giant 1960 Chile earthquake of magnitude 9.5 (ref. 3). Although the time since the preceding earthquake spanned 123 years (refs 4, 5), the estimated slip in 1960, which occurred on a fault between the Nazca and South American tectonic plates, equalled 250-350 years' worth of the plate motion. Thus the average interval between such giant earthquakes on this fault should span several centuries. Here we present evidence that such long intervals were indeed typical of the last two millennia. We use buried soils and sand layers as records of tectonic subsidence and tsunami inundation at an estuary midway along the 1960 rupture. In these records, the 1960 earthquake ended a recurrence interval that had begun almost four centuries before, with an earthquake documented by Spanish conquistadors in 1575. Two later earthquakes, in 1737 and 1837, produced little if any subsidence or tsunami at the estuary and they therefore probably left the fault partly loaded with accumulated plate motion that the 1960 earthquake then expended. PMID:16163355

  6. Equity in health care utilization in Chile.

    PubMed

    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 and the 2006 Satisfaction and Out-of-Pocket Payment Survey to assess equity in health care utilization using two different approaches. First, we used a two-part model to estimate factors associated with the utilization of health care. Second, we decomposed income-related inequalities in medical care use into contributions of need and non-need factors and estimated a horizontal inequity index.Findings of this empirical study include evidence of inequities in the Chilean health care system that are beneficial to the better-off. We also identified some key factors, including education and health care payment, which affect the utilization of health care services. Results of this study could help researchers and policy makers identify targets for improving equity in health care utilization and strengthening availability of health care services accordingly. PMID:23937894

  7. Equity in health care utilization in Chile.

    PubMed

    Núñez, Alicia; Chi, Chunhuei

    2013-08-12

    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 and the 2006 Satisfaction and Out-of-Pocket Payment Survey to assess equity in health care utilization using two different approaches. First, we used a two-part model to estimate factors associated with the utilization of health care. Second, we decomposed income-related inequalities in medical care use into contributions of need and non-need factors and estimated a horizontal inequity index.Findings of this empirical study include evidence of inequities in the Chilean health care system that are beneficial to the better-off. We also identified some key factors, including education and health care payment, which affect the utilization of health care services. Results of this study could help researchers and policy makers identify targets for improving equity in health care utilization and strengthening availability of health care services accordingly.

  8. Equity in health care utilization in Chile

    PubMed Central

    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 and the 2006 Satisfaction and Out-of-Pocket Payment Survey to assess equity in health care utilization using two different approaches. First, we used a two-part model to estimate factors associated with the utilization of health care. Second, we decomposed income-related inequalities in medical care use into contributions of need and non-need factors and estimated a horizontal inequity index. Findings of this empirical study include evidence of inequities in the Chilean health care system that are beneficial to the better-off. We also identified some key factors, including education and health care payment, which affect the utilization of health care services. Results of this study could help researchers and policy makers identify targets for improving equity in health care utilization and strengthening availability of health care services accordingly. PMID:23937894

  9. Family allowance and family planning in Chile.

    PubMed Central

    Plank, S J

    1978-01-01

    Family allowances designed to promote maternal and child health and welfare could be self-defeating if they stimulated otherwise unwanted births, as often assumed. That assumption, with its public health and demographic implications, needs testing. An attempt to test it was made in Chile in 1969--1970 through interviews with 945 wives receiving an allowance and 690 non-recipients. Recipients practiced contraception significantly more than did non-recipients. This was not explained by wives' educational attainment or employment, the couples' earnings, or number of living children, but was associated with a 50 per cent greater utilization of professional prenatal care by recipients during the most recent pregnancy; women with such care (regardless of allowance status) were 75 per cent more likely than others to control their fertility. Prenatal care was probably sought more by recipients in part because an additional stipend was provided as soon as pregnancy was confirmed, usually at clinics with integrated family planning. Greater family income, attributable to the allowance, probably also contributed to the recipients' better prenatal attention and to contraceptive practice. Noteworthy, too, was the finding that with the number of living children controlled, contraceptive practice was significantly greater amoung couples who had never lost a child. PMID:717610

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

    PubMed

    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.

  11. [Mental health in Chile and Finland: Challenges and lessons].

    PubMed

    Retamal C, Pedro; Markkula, Niina; Peña, Sebastián

    2016-07-01

    This article analyses and compares the epidemiology of mental disorders and relevant public policies in Chile and Finland. In Chile, a specific mental health law is still lacking. While both countries highlight the role of primary care, Finland places more emphasis on participation and recovery of service users. Comprehensive mental health policies from Finland, such as a successful suicide prevention program, are presented. Both countries have similar prevalence of mental disorders, high alcohol consumption and high suicide rates. In Chile, the percentage of total disease burden due to psychiatric disorders is 13% and in Finland 14%. However, the resources to address these issues are very different. Finland spends 4.5% of its health budget on mental health, while in Chile the percentage is 2.2%. This results in differences in human resources and service provision. Finland has five times more psychiatric outpatient visits, four times more psychiatrists, triple antidepressant use and twice more clinical guidelines for different psychiatric conditions. In conclusion, both countries have similar challenges but differing realities. This may help to identify gaps and potential solutions for public health challenges in Chile. Finland’s experience demonstrates the importance of political will and long-term vision in the construction of mental health policies.

  12. [Mental health in Chile and Finland: Challenges and lessons].

    PubMed

    Retamal C, Pedro; Markkula, Niina; Peña, Sebastián

    2016-07-01

    This article analyses and compares the epidemiology of mental disorders and relevant public policies in Chile and Finland. In Chile, a specific mental health law is still lacking. While both countries highlight the role of primary care, Finland places more emphasis on participation and recovery of service users. Comprehensive mental health policies from Finland, such as a successful suicide prevention program, are presented. Both countries have similar prevalence of mental disorders, high alcohol consumption and high suicide rates. In Chile, the percentage of total disease burden due to psychiatric disorders is 13% and in Finland 14%. However, the resources to address these issues are very different. Finland spends 4.5% of its health budget on mental health, while in Chile the percentage is 2.2%. This results in differences in human resources and service provision. Finland has five times more psychiatric outpatient visits, four times more psychiatrists, triple antidepressant use and twice more clinical guidelines for different psychiatric conditions. In conclusion, both countries have similar challenges but differing realities. This may help to identify gaps and potential solutions for public health challenges in Chile. Finland’s experience demonstrates the importance of political will and long-term vision in the construction of mental health policies. PMID:27661557

  13. [The evolution theory in the medical sciences in Chile].

    PubMed

    Cruz-Coke, R

    1994-02-01

    The evolutionist ideas of Lamarck, Darwin and Haeckel entered the country through the arrival of their books. "On the origin of Species" arrived in Chile in 1869. The most outstanding immigrant european physicians that discussed these ideas were Rodulfo A Phillippi (1808-1904) and Juan José Brunner (1825-1899). Both discussed Darwin's ideas in their books and conferences as academics of the Faculty of Medicine of the University of Chile. The first Chilean physicians that read and discussed the validity of evolution theory were Adolfo Valderrama (1834-1902) and Pedro Candia Salgado. Both wrote articles about this matter in Revista Médica de Chile in 1872 and 1874. The professor of general biology, Juan Noé Crevani, italian physician and zoologist that arrived in Chile in 1912, was the first to teach directly the concepts of the evolution theory until his death in 1947. Professor Noé founded the great biological school of the twentieth century in Chile and his disciples introduced the concepts of Mendelian theory and neodarwinism in the decade of fifties. The theory of evolution was taught as a chapter of general biology in the Faculty of Medicine between 1913 and 1947, but its practical applications to medicine were introduced with the birth of medical genetics in the decade of fifties and the foundation of Chilean Genetics society in 1964, under the direction of professors Danko Brncic and Gustavo Hoecker, both awarded with the National Sciences Prize.

  14. Body image and weight status of children from rural areas of Valparaíso, Chile.

    PubMed

    Lizana, Pablo A; Simpson, Cristina; Yáñez, Lily; Saavedra, Karime

    2014-11-30

    Introducción: La obesidad en niños es un problema multifactorial, entre ellos se encuentra la percepción que tienen de su propio peso. Objetivo: Determinar la concordancia entre el estado nutricional percibido y el real en escolares de áreas rurales. Métodos: Comprenden 206 estudiantes de primer a octavo año de enseñanza primaria de establecimientos rurales de la región de Valparaíso, Chile (43% mujeres). El estado nutricional real se evaluó a través del índice de masa corporal (IMC) y la percibida mediante figuras corporales. El nivel socioeconómico (NSE) se determinó mediante la escala de Graffar modificada. Los análisis se realizaron utilizando el coeficiente de concordancia kappa y para la asociación de variables se utilizó la prueba X2. Resultados: Los sujetos se concentran en el NSE bajo (82% hombres; 72% mujeres). 49.5% de los escolares presenta sobrepeso y obesidad. Los hombres presentan una mayor prevalencia de obesidad (29%) que las mujeres (20%). El 62,5% de las mujeres subestiman su peso, cifra mayor que en el caso de los hombres (52,5%). El 98,10% de los individuos obesos subestiman su peso y el 100% de los niños estudiados en condición de sobrepeso también lo subestiman. Conclusiones: Los niños y niñas de contextos rurales en condición de sobrepeso y obesidad son los que presentan la mayor prevalencia de una inadecuada percepción de la imagen corporal (subestimación) lo cual tiene un importante impacto al no reconocer su condición de malnutrición por exceso. Esta condición puede tener importantes repercusiones en salud pública, puesto que esta condición se puede mantener hasta la vida adulta, desarrollando enfermedades crónicas no transmisibles.

  15. 75 FR 10846 - The Chile Fund, Inc., et al.; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-09

    .... Applicants: The Chile Fund, Inc. (``Chile Fund''), Aberdeen Australia Equity Fund (``Australia Fund... requested order would supersede a prior order issued to the Australia Fund. DATES: Filing Dates: The... ``Chile Fund Board'' and the ``Australia Fund Board'') or the board of directors or trustees of...

  16. CHILE: An Evidence-Based Preschool Intervention for Obesity Prevention in Head Start

    ERIC Educational Resources Information Center

    Davis, Sally M.; Sanders, Sarah G.; FitzGerald, Courtney A.; Keane, Patricia C.; Canaca, Glenda F.; Volker-Rector, Renee

    2013-01-01

    Background: Obesity is a major concern among American Indians and Hispanics. The Child Health Initiative for Lifelong Eating and Exercise (CHILE) is an evidence-based intervention to prevent obesity in children enrolled in 16 Head Start (HS) Centers in rural communities. The design and implementation of CHILE are described. Methods: CHILE uses a…

  17. 19 CFR 10.490 - Goods re-entered after repair or alteration in Chile.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Chile. 10.490 Section 10.490 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND... States-Chile Free Trade Agreement Goods Returned After Repair Or Alteration § 10.490 Goods re-entered after repair or alteration in Chile. (a) General. This section sets forth the rules which apply...

  18. Geophysical variables and behavior: LX. Lonquimay and Alhué, Chile: tension from volcanic and earthquake hazard.

    PubMed

    Larraín, P; Simpson-Housley, P

    1990-02-01

    This study assesses the effect of trait anxiety scores on subjects' responses to volcanic eruption hazard and earthquake hazard in Lonquimay and Alhué, respectively. Lonquimay is located in the southern Chilean Andes and Alhué is located in central Chile in the Coastal Range. The former was afflicted by a volcanic eruption which commenced on Christmas Day 1988 and the latter by an earthquake on March 3, 1985. Expectations of high damage and fear from a radio hazard prediction were associated with high trait-anxiety scores in the Alhué sample while positive adjustments to extenuate the hazard effect reached significance for the Lonquimay sample.

  19. Trail impacts and trail impact management related to ecotourism visitation at Torres del Paine National Park, Chile

    USGS Publications Warehouse

    Farrell, T.A.; Marion, J.L.

    2002-01-01

    Ecotourism and protected area visitation in Central and South America are largely dependent upon a relatively undisturbed quality of natural resources. However, visitation may impact vegetation, soil, water and wildlife resources, and degrade visitor facilities such as recreation sites and trails. Findings are reported from trail impact research conducted at Torres del Paine National Park in Patagonia, Chile. The frequency and magnitude of selected trail impacts and the relative effect of the amount of use, vegetation type, trail position and trail grade are investigated. Findings differed from previous studies in that amount of use was significantly related to both trail width increases and trail erosion. Management actions to minimize trail impacts are offered.

  20. The Unexpected Awakening of Chaitén Volcano, Chile

    NASA Astrophysics Data System (ADS)

    Carn, Simon A.; Pallister, John S.; Lara, Luis; Ewert, John W.; Watt, Sebastian; Prata, Alfred J.; Thomas, Ronald J.; Villarosa, Gustavo

    2009-06-01

    On 2 May 2008, a large eruption began unexpectedly at the inconspicuous Chaitén volcano in Chile's southern volcanic zone. Ash columns abruptly jetted from the volcano into the stratosphere, followed by lava dome effusion and continuous low-altitude ash plumes [Lara, 2009]. Apocalyptic photographs of eruption plumes suffused with lightning were circulated globally. Effects of the eruption were extensive. Floods and lahars inundated the town of Chaitén, and its 4625 residents were evacuated. Widespread ashfall and drifting ash clouds closed regional airports and cancelled hundreds of domestic flights in Argentina and Chile and numerous international flights [Guffanti et al., 2008]. Ash heavily affected the aquaculture industry in the nearby Gulf of Corcovado, curtailed ecotourism, and closed regional nature preserves. To better prepare for future eruptions, the Chilean government has boosted support for monitoring and hazard mitigation at Chaitén and at 42 other highly hazardous, active volcanoes in Chile.

  1. The Unexpected Awakening of Chaitén Volcano, Chile

    USGS Publications Warehouse

    Carn, Simon A.; Zogorski, John S.; Lara, Luis; Ewert, John W.; Watt, Sebastian; Prata, Alfred J.; Thomas, Ronald J.; Villarosa, Gustavo

    2009-01-01

    On 2 May 2008, a large eruption began unexpectedly at the inconspicuous Chaitén volcano in Chile's southern volcanic zone. Ash columns abruptly jetted from the volcano into the stratosphere, followed by lava dome effusion and continuous low-altitude ash plumes [Lara, 2009]. Apocalyptic photographs of eruption plumes suffused with lightning were circulated globally. Effects of the eruption were extensive. Floods and lahars inundated the town of Chaitén, and its 4625 residents were evacuated. Widespread ashfall and drifting ash clouds closed regional airports and cancelled hundreds of domestic flights in Argentina and Chile and numerous international flights [Guffanti et al., 2008]. Ash heavily affected the aquaculture industry in the nearby Gulf of Corcovado, curtailed ecotourism, and closed regional nature preserves. To better prepare for future eruptions, the Chilean government has boosted support for monitoring and hazard mitigation at Chaitén and at 42 other highly hazardous, active volcanoes in Chile.

  2. Analysis and projections of physics in Chile

    NASA Astrophysics Data System (ADS)

    Soto, Leopoldo; Zambra, Marcelo; Loewe, Marcelo; Gutiérrez, Gonzalo; Molina, Mario; Barra, Felipe; Lund, Fernando; Saavedra, Carlos; Haberle, Patricio

    2008-11-01

    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 Tecnología (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 insufficient

  3. Source Process of the 2007 Mw 7.7 Tocopilla, Chile Earthquake

    NASA Astrophysics Data System (ADS)

    Minson, S. E.; Simons, M.; Owen, S.; Genrich, J.; Galetzka, J.; Chowdhury, F. R.; Webb, F.; Beck, J. L.; Comte, D.; Glass, B.; Leiva, C.

    2008-12-01

    The magnitude 7.7 Tocopilla earthquake of November 14, 2007 ruptured a stretch of the northern Chile subduction zone just north of the 1995 Antofagasta earthquake source region. In this study, we compare a Bayesian analysis with a simulated annealing inversion methodology to determine a finite fault rupture model for the Tocopilla earthquake. While we also incorporate both teleseismic data and satellite radar images, high-rate (5 samples/sec) GPS data provides particularly important constraints on the source process of this event. Because the Tocopilla earthquake was located immediately coastward of the CANTO (Central ANdean Tectonic Observatory) geodetic network, the evolution of the local slip field is well-recorded. We find that the high-rate continuous GPS data is key to determining the location of the hypocenter and asperities as well as the evolution of slip. Most of the slip is located east of the coastline with at least two distinct regions of concentrated slip.

  4. [Measles: the disease, epidemiology, history and vaccination programs in Chile].

    PubMed

    Delpiano, Luis; Astroza, Leonor; Toro, Jorge

    2015-08-01

    Measles, one of most important inmuno-preventable diseases, remains as a worldwide concern issue with an important morbidity and mortality. Particularly in the America region declared free of measles in 2010 by WHO, they still appear imported cases that origin outbreaks of variable magnitude in susceptible subjects usually none vaccinated which is the current situation in Santiago, the capital city of Chile. In this review we present characteristics of the etiological agent, the disease, epidemiological aspects with national historical focus, impact of immunization programs and outbreaks in Chile, in order to contribute to knowledge and management of this always present public health problem. PMID:26436786

  5. New records of feather lice from some seabirds in Chile.

    PubMed

    Sepúlveda, M S; Palma, R L; Ochoa-Acuña, H

    1997-04-01

    Six species of chewing lice (Phthiraptera: Menoponidae, Philopteridae) are reported from four species of seabirds collected off the coast of Chile. They are Eidmanniella pellucida, Piagetiella transitans, and Piagetiella caputincisa, from a Guanay cormorant (Phalacrocorax bougainvillii); Harrisoniella ferox collected from a black-browed albatross (Diomedea melanophrys); Ancistrona vagelli from a white-necked petrel (Pterodroma externa); and Pelmatocerandra flinti collected from a Magellan diving petrel (Pelecanoides magellani). Eidmanniella pellucida and P. transitans are reported from Chile for the first time. Piagetiella caputincisa from the Guanay cormorant may be a contaminant from a red-legged shag (Phalacrocorax gaimardi). PMID:9131581

  6. [Measles: the disease, epidemiology, history and vaccination programs in Chile].

    PubMed

    Delpiano, Luis; Astroza, Leonor; Toro, Jorge

    2015-08-01

    Measles, one of most important inmuno-preventable diseases, remains as a worldwide concern issue with an important morbidity and mortality. Particularly in the America region declared free of measles in 2010 by WHO, they still appear imported cases that origin outbreaks of variable magnitude in susceptible subjects usually none vaccinated which is the current situation in Santiago, the capital city of Chile. In this review we present characteristics of the etiological agent, the disease, epidemiological aspects with national historical focus, impact of immunization programs and outbreaks in Chile, in order to contribute to knowledge and management of this always present public health problem.

  7. Tamarugal basin exploration under way in northern Chile

    SciTech Connect

    Roos, M.

    1996-12-30

    The government of Chile has awarded an exploration contract to Cardinal Resources Inc., headquartered in White Plains, N.Y., to develop oil and natural gas for commercial production on a large inland tract in northern Chile. Recent geological/geophysical evaluations of the contract area by both Cardinal and Empresa Nacional del Petroleol (ENAP), the state energy company, have upgraded the hydrocarbon potential of this northern basin, making it an attractive exploration play. The paper describes the contract area, two oil seeps that have been discovered, structural history, Jurassic stratigraphy, and interpretation of the aeromagnetic and Landsat data.

  8. Improving the flow representation in a stochastic programming model for hydropower operations in Chile

    NASA Astrophysics Data System (ADS)

    Morales, Y.; Olivares, M. A.; Vargas, X.

    2015-12-01

    This research aims to improve the representation of stochastic water inflows to hydropower plants used in a grid-wide, power production scheduling model in central Chile. The model prescribes the operation of every plant in the system, including hydropower plants located in several basins, and uses stochastic dual dynamic programming (SDDP) with possible inflow scenarios defined from historical records. Each year of record is treated as a sample of weekly inflows to power plants, assuming this intrinsically incorporates spatial and temporal correlations, without any further autocorrelation analysis of the hydrological time series. However, standard good practice suggests the use of synthetic flows instead of raw historical records.The proposed approach generates synthetic inflow scenarios based on hydrological modeling of a few basins in the system and transposition of flows with other basins within so-called homogeneous zones. Hydrologic models use precipitation and temperature as inputs, and therefore this approach requires producing samples of those variables. Development and calibration of these models imply a greater demand of time compared to the purely statistical approach to synthetic flows. This approach requires consideration of the main uses in the basins: agriculture and hydroelectricity. Moreover a geostatistical analysis of the area is analyzed to generate a map that identifies the relationship between the points where the hydrological information is generated and other points of interest within the power system. Consideration of homogeneous zones involves a decrease in the effort required for generation of information compared with hydrological modeling of every point of interest. It is important to emphasize that future scenarios are derived through a probabilistic approach that incorporates the features of the hydrological year type (dry, normal or wet), covering the different possibilities in terms of availability of water resources. We present

  9. Monitoring the northern Chile megathrust with the Integrated Plate boundary Observatory Chile (IPOC)

    NASA Astrophysics Data System (ADS)

    Schurr, Bernd; Asch, Günter; Cailleau, Beatrice; Diaz, Guillermo Chong; Barrientos, Sergio; Vilotte, Jean-Pierre; Oncken, Onno

    2010-05-01

    The oceanic Nazca plate subducts beneath the continental South American plate by recurrent rupture of large segments of its interface. The resulting earthquakes are among the largest and most frequent on Earth. Along the Chilean and southern Peruvian margin, all sizeable segments have ruptured at least once in the past 150 years for which there exist historic and/or instrumental records. The one segment that is most mature for re-rupture stretches for more than 500 km along the northernmost Chilean coast between roughly -23° and -18° latitude. It last broke in 1877 in a magnitude ~8.5 earthquake, triggering a major Tsunami. From the historical record, it has been known to have a recurrence cycle of approximately 110 years. The adjoining segments to the south and north broke rather recently in 1995 and 2001 in M>8 earthquakes and an M 7.7 earthquake intruded into the southern part of the seismic gap in 2007 between Antofagasto and Tocopilla. This makes northern Chile a unique natural laboratory to observe a subduction megathrust at various stages of its seismic cycle. For that purpose, installation of long-term observatories started in 2006 in a close cooperation of the Universidad de Chile (Santiago, Chile), the Universidad Catolica del Norte (Antofagasta, Chile), the Institut de Physique du Globe de Paris (France), and the GFZ German research Centre for Geosciences (Germany). Currently we are operating 17 modern seismological stations equipped with STS-2 broadband seismometers and accelerometers (EPI sensor). At least two more stations will be installed in the near future. Continuous GPS, tilt, creep, climate and magnetotellurics measurements are complementing the seismological part. A majority of the sites provide data near real-time. We will present results of seismic monitoring including analysis of the 2007 M7.7 Tocopilla earthquake sequence that was recorded during the installation stage of the observatory. We relocated the mainshock and about a one

  10. Detailed Axial Morphology of the Chile Rise as it Approaches the Chile Triple Junction

    NASA Astrophysics Data System (ADS)

    Blackman, D. K.; Henig, A. S.; Barroso, E.; Grevemeyer, I.; Thurber, A. R.; German, C. R.; Inspire Cruise Participants, T.

    2010-12-01

    New bathymetric mapping along the two southernmost Chile Rise spreading segments shows axial volcanic structure that had not been evident in prior data. On the first segment extending north from the triple junction, where the basement is not obscured by sediment, a narrow line of volcanic structures appears to track the center of the rift valley. However, the next segment north, which is offset almost 50 km along a transform fault, has axial volcanic features that vary in position within the rift valley. In the northern ~half of this segment, lineated small volcanic structures hug the eastern scarp of the rift whereas in the south they are apparent only along the western part of the valley floor. A classic ridge-transform intersection (RTI) nodal deep occurs at this southern end of the segment. The position of the basin is asymmetric relative to the axis, toward the ‘inside corner’ on the eastern side of the rift valley. It is intriguing that the nodal deep, which is often modeled as the result of viscous mantle upwelling and plate stresses at an RTI, is centered on the opposite side of the rift valley from where the most recent volcanic activity occurred. Presumably this reflects interplay between local magma plumbing and tectonic stresses. In addition to the local ridge-transform forces, regional factors associated with subduction along the edge of the Cocos plate may affect mantle flow, melting, and detailed plate kinematics. We will present maps that combine the new Simrad EM122 swath sonar data, obtained during cruise MV1003 aboard R/V Melville, with pre-existing German and Chilean bathymetric grids. We will also discuss some of the tectonic and magmatic implications of the observed detailed morphologic patterns. As one of the few areas on the globe where active subduction and spreading occur in close proximity, the southernmost Chile rise presents a natural laboratory for studying the manifestations of interaction between these processes.

  11. The 2015 Illapel Earthquake in Chile: Initial Findings

    NASA Astrophysics Data System (ADS)

    Barrientos, S. E.

    2015-12-01

    On September 16, 2015 at 19:54 hrs (local time) a magnitude 8.3 earthquake took place off the coast of the Coquimbo Region in central Chile. The National Seismological Centre (CSN) reported epicentral coordinates 71.864°W and 31.553°S and a W-phase magnitude of 8.4 This earthquake is the largest in the country since the February 27, 2010 event and the third largest since May 22, 1960, surpassing in size the one that took place off the coast of Iquique- Pisagua on April 1, 2014. Unlike the later, the 2015 earthquake showed no recognizable immediate precursor activity in the epicentral area. Focal mechanisms of the mainshock and larger aftershocks are consistent with the displacement of the Nazca plate beneath the South American plate. The previous large earthquakes of similar size took place in this region on April 6, 1943, with a magnitude of 7.9 (Beck et al., 1998); Abe (1979) lists this earthquake with tsunami magnitude equivalent to 8.2 Preliminary estimates of the slip distribution, based on GNSS data, indicate that the rupture length reaches about 200-250 km with a maximum displacement of the order of 6 m. Coastal uplift of 40 cm close to the epicentral area is evidenced by biological markers. The epicenter is not located either at the region of maximum or minimum slip, but where there is a strong fault displacement gradient. Number of daily aftershocks within the first four weeks is decaying with a p-value of the order of 0.8 to 1. An anomalous maximum acceleration of the order of 80% g was recorded on the E-W horizontal component of the station located at a station in Montepatria, more than 80 km away from the region of maximum slip. Because the general area recorded values of 30%g, it is very likely that this high acceleration is due to ground effects. Historical seismicity in the region is examined to understand the possible future scenarios of large earthquakes. To the north, the 1922 (Mw=8.4, Mt=8.7) has been the last to rupture this zone; to the south

  12. Subduction zone guided waves in Northern Chile

    NASA Astrophysics Data System (ADS)

    Garth, Thomas; Rietbrock, Andreas

    2016-04-01

    Guided wave dispersion is observed in subduction zones as high frequency energy is retained and delayed by low velocity structure in the subducting slab, while lower frequency energy is able to travel at the faster velocities associated with the surrounding mantle material. As subduction zone guided waves spend longer interacting with the low velocity structure of the slab than any other seismic phase, they have a unique capability to resolve these low velocity structures. In Northern Chile, guided wave arrivals are clearly observed on two stations in the Chilean fore-arc on permanent stations of the IPOC network. High frequency (> 5 Hz) P-wave arrivals are delayed by approximately 2 seconds compared to the low frequency (< 2 Hz) P-wave arrivals. Full waveform finite difference modelling is used to test the low velocity slab structure that cause this P-wave dispersion. The synthetic waveforms produced by these models are compared to the recorded waveforms. Spectrograms are used to compare the relative arrival times of different frequencies, while the velocity spectra is used to constrain the relative amplitude of the arrivals. Constraining the waveform in these two ways means that the full waveform is also matched, and the low pass filtered observed and synthetic waveforms can be compared. A combined misfit between synthetic and observed waveforms is then calculated following Garth & Rietbrock (2014). Based on this misfit criterion we constrain the velocity model by using a grid search approach. Modelling the guided wave arrivals suggest that the observed dispersion cannot be solely accounted for by a single low velocity layer as suggested by previous guided wave studies. Including dipping low velocity normal fault structures in the synthetic model not only accounts for the observed strong P-wave coda, but also produces a clear first motion dispersion. We therefore propose that the lithospheric mantle of the subducting Nazca plate is highly hydrated at intermediate

  13. Neoliberal Education and Student Movements in Chile: Inequalities and Malaise

    ERIC Educational Resources Information Center

    Cabalin, Cristian

    2012-01-01

    This article examines the major consequences of the neoliberal education system implemented in Chile during the dictatorship of Augusto Pinochet and how two important student movements contested this structure. In 2006 and 2011, thousands of students filled the streets to demand better public education, more social justice and equal opportunities.…

  14. Popular Education for Peasant Communities in Chile. Chapter 21.

    ERIC Educational Resources Information Center

    Infante R., Isabel; Letelier G., Eugenia

    The rural population of Chile has been served poorly by the formal educational system, rural educational attainment lags behind that of urban areas, and outmigration and alienation of rural youth are high. In the past decade, popular education has attempted to educate rural people and put them in control of their destinies by drawing on popular…

  15. International Reports on Literacy Research: Chile, Argentina, Brazil, and Colombia

    ERIC Educational Resources Information Center

    Malloy, Jacquelynn A., Comp.; Botzakis, Stergios, Comp.

    2005-01-01

    This is a compilation of reports on international literacy research. The report includes 4 separate reports on Chile, Argentina, Brazil, and Colombia. In the first report, research correspondent Marta Infante reports on two studies that reflect the growing interest of Chilean professionals in studying reading-related factors such as phonemic…

  16. Special Education for the Learning Disabled in Chile.

    ERIC Educational Resources Information Center

    Bravo-Valdivieso, Luis

    The paper focuses on the growth and development of special education for learning disabled children in Chile with particular emphasis on the contribution of child psychiatry and pediatric neurology departments of hospitals and the contribution of universities in training specialists. Initial sections provide a background on primary education in…

  17. Education with ICT in South Korea and Chile

    ERIC Educational Resources Information Center

    Sanchez, Jaime; Salinas, Alvaro; Harris, Jordan

    2011-01-01

    This article presents a linear-analytical case study on the development of ICT within the educational systems of Chile and South Korea. Through a comprehensive meta-data analysis and bibliographic review, we collected information on both educational systems and their ICT adoption policies. Key differences necessary to understand how both countries…

  18. The Impact of Chile's School Feeding Program on Education Outcomes

    ERIC Educational Resources Information Center

    McEwan, Patrick J.

    2013-01-01

    Chile operates one of the oldest and largest school feeding programs in Latin America, targeting higher-calorie meals to relatively poorer schools. This paper evaluates the impact of higher-calorie meals on the education outcomes of public, rural schools and their students. It applies a regression-discontinuity design to administrative data,…

  19. National Television of Chile--New headquarters building acoustic projects

    NASA Astrophysics Data System (ADS)

    Huaquin, Mario

    2002-11-01

    In the last 15 years TV stations in Chile have been incorporating in their facilities architectural acoustic and noise control approaches. This has been necessary as much for the technological advance, as for the necessity to achieve a better quality of sound that the listeners receive. In 1998, the National Television of Chile, with the sponsorship of the College of Architects of Chile, requested preliminary architectural designs in order to enlarge and to renovate its headquarters buildings in Santiago, Chile in stages. The Acoustic Project has been developed in an integral way, with three fundamental disciplines: noise and noise control; Machine rooms; vibrations and vibration control; Buildings, engines; architectural acoustics and acoustic comfort; TV studios and technical rooms. This presentation describes the Acoustic Project, phases I (1999), and II (2002), how it was possible to establish a common language with architects and engineers and the different specialties, to apply acoustic criteria and standards, the theoretical development and the projected acoustic solutions. (To be presented in Spanish.)

  20. New species of Anisophya Karabag from Chile (Orthoptera: Tettigoniidae: Phanopterinae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Many of the most primitive Neotropical bush katydids (Phaneropterinae) — including species of Cosmophyllum Blanchard, Stenophylla Brunner von Wattenwyl, Marenestha Brunner von Wattenwyl, Anisophya Karabag, Coryphoda Brunner von Wattenwyl, and Burgilis Stål — are endemic in Chile. The Chilean species...

  1. How Local Market Pressures Shape Leadership Practices: Evidence from Chile

    ERIC Educational Resources Information Center

    Carrasco, Alejandro; Fromm, Germán

    2016-01-01

    Chile is well known worldwide for its extensive use of market-driven mechanisms in education. Using a case study strategy in three schools, this paper shows that "universal" voucher system and mixed provision (co-existence of subsidised private and state-funded schools) policies are reshaping school management practices. The paper draws…

  2. Accreditation in Higher Education in Chile: Results and Consequences

    ERIC Educational Resources Information Center

    Espinoza, Oscar; Gonzalez, Luis Eduardo

    2013-01-01

    Purpose: The purpose of this paper is to analyze and discuss the results that the accreditation system implemented in Chile has brought to higher education institutions and undergraduate and graduate programs, taking into account both its positive and negative implications. Design/methodology/approach: The examination of the Chilean accreditation…

  3. The New Student Loan System in Chile's Higher Education

    ERIC Educational Resources Information Center

    Larrain, Christian; Zurita, Salvador

    2008-01-01

    Chile's higher education system stands out as being one of the most privatized and open to the market in the world. Recently, the Chilean Congress passed Law #20.027 of 2005, which provides the legal framework for the creation of a student loan system guaranteed both by the State and by higher education institutions (HEIs), financed by the private…

  4. Creating Dialogues: Exploring the "Good Early Childhood Educator" in Chile

    ERIC Educational Resources Information Center

    Viviani, Maria

    2016-01-01

    The aim of this study was to explore the different ways in which a number of Chilean stakeholders conceptualise the "good early childhood educator" in Chile. In a context where new foreign narratives are increasingly dominating the field and the recent standardisation of the educators' professional role is being implemented, this…

  5. The Araucanian Indian in Chile. IWGIA Document 20.

    ERIC Educational Resources Information Center

    Berdichewsky, Bernardo

    One of the larger of the native peoples of South America, the Araucanians include different ethnic subgroups, some of which are now extinct. Once geographically spread extensively over the southern cone of South America, at present they are reduced to only two closely related groups: (1) the Mapuche of southern Chile, the largest one; and (2) the…

  6. Hydrothermal Exploration at the Chile Triple Junction - ABE's last adventure?

    NASA Astrophysics Data System (ADS)

    German, C. R.; Shank, T. M.; Lilley, M. D.; Lupton, J. E.; Blackman, D. K.; Brown, K. M.; Baumberger, T.; Früh-Green, G.; Greene, R.; Saito, M. A.; Sylva, S.; Nakamura, K.; Stanway, J.; Yoerger, D. R.; Levin, L. A.; Thurber, A. R.; Sellanes, J.; Mella, M.; Muñoz, J.; Diaz-Naveas, J. L.; Inspire Science Team

    2010-12-01

    In February and March 2010 we conducted preliminary exploration for hydrothermal plume signals along the East Chile Rise where it intersects the continental margin at the Chile Triple Junction (CTJ). This work was conducted as one component of our larger NOAA-OE funded INSPIRE project (Investigation of South Pacific Reducing Environments) aboard RV Melville cruise MV 1003 (PI: Andrew Thurber, Scripps) with all shiptime funded through an award of the State of California to Andrew Thurber and his co-PI's. Additional support came from the Census of Marine Life (ChEss and CoMarge projects). At sea, we conducted a series of CTD-rosette and ABE autonomous underwater vehicle operations to prospect for and determine the nature of any seafloor venting at, or adjacent to, the point where the the East Chile Rise subducts beneath the continental margin. Evidence from in situ sensing (optical backscatter, Eh) and water column analyses of dissolved CH4, δ3He and TDFe/TDMn concentrations document the presence of two discrete sites of venting, one right at the triple junction and the other a further 10km along axis, north of the Triple Junction, but still within the southernmost segment of the East Chile Rise. From an intercomparison of the abundance of different chemical signals we can intercompare likely characteristics of these differet source sites and also differentiate between them and the high methane concentrations released from cold seep sites further north along the Chile Margin, both with the CTJ region and also at the Concepcion Methane Seep Area (CMSA). This multi-disciplinary and international collaboration - involving scientists from Chile, the USA, Europe and Japan - can serve as an excellent and exciting launchpoint for wide-ranging future investigations of the Chile Triple Junction area - the only place on Earth where an oceanic spreading center is being actively subducted beneath a continent and also the only place on Earth where all known forms of deep

  7. First detection, isolation and molecular characterization of infectious salmon anaemia virus associated with clinical disease in farmed Atlantic salmon (Salmo salar) in Chile

    PubMed Central

    Godoy, Marcos G; Aedo, Alejandra; Kibenge, Molly JT; Groman, David B; Yason, Carmencita V; Grothusen, Horts; Lisperguer, Angelica; Calbucura, Marlene; Avendaño, Fernando; Imilán, Marcelo; Jarpa, Miguel; Kibenge, Frederick SB

    2008-01-01

    Background Infectious salmon anaemia (ISA) is a viral disease of marine-farmed Atlantic salmon (Salmo salar) caused by ISA virus (ISAV), which belongs to the genus Isavirus, family Orthomyxoviridae. The virus is considered to be carried by marine wild fish and for over 25 years has caused major disease outbreaks in marine-farmed Atlantic salmon in the Northern hemisphere. In the Southern hemisphere, ISAV was first detected in Chile in 1999 in marine-farmed Coho salmon (Oncorhynchus kisutch). In contrast to the classical presentation of ISA in Atlantic salmon, the presence of ISAV in Chile until now has only been associated with a clinical condition called Icterus Syndrome in Coho salmon and virus isolation has not always been possible. During the winter of 2007, unexplained mortalities were registered in market-size Atlantic salmon in a grow-out site located in Chiloé in Region X of Chile. We report here the diagnostic findings of the first significant clinical outbreak of ISA in marine-farmed Atlantic salmon in Chile and the first characterization of the ISAV isolated from the affected fish. Results In mid-June 2007, an Atlantic salmon marine farm site located in central Chiloé Island in Region X of Chile registered a sudden increase in mortality following recovery from an outbreak of Pisciricketsiosis, which rose to a cumulative mortality of 13.6% by harvest time. Based on the clinical signs and lesions in the affected fish, and laboratory tests performed on the fish tissues, a confirmatory diagnosis of ISA was made; the first time ISA in its classical presentation and for the first time affecting farmed Atlantic salmon in Chile. Rapid sequencing of the virus-specific RT-PCR products amplified from the fish tissues identified the virus to belong to the European genotype (Genotype I) of the highly polymorphic region (HPR) group HPR 7b, but with an 11-amino acid insert in the fusion glycoprotein, and ability to cause cytopathic effects (CPE) in CHSE-214 cell line

  8. Central line infections - hospitals

    MedlinePlus

    ... infection; CVC - infection; Central venous device - infection; Infection control - central line infection; Nosocomial infection - central line infection; Hospital acquired infection - central line infection; Patient safety - central ...

  9. Worthy Women of Chile: What Role Did They Play? Fulbright-Hays Summer Seminar Abroad Program 1995 (Chile).

    ERIC Educational Resources Information Center

    Hertzberg, Ruth A.

    This paper describes the lives of some notable women in the history of Chile from the time of the conquistadors to the present. The significant women described in the paper include: (1) Ines de Suarez (accompanied Pedro de Validivia in 1544); (2) Micaela Bastidas Puyucahua (wife of Incan leader Jose Gabriel Tupac Amaru, about 1780); (3) Gabriela…

  10. Paleomagnetic evidence of earliest Paleocene deformation in Calama (˜22°S), northern Chile: Andean-type or ridge-collision tectonics?

    NASA Astrophysics Data System (ADS)

    Somoza, R.; Tomlinson, A. J.; Caffe, P. J.; Vilas, J. F.

    2012-08-01

    A paleomagnetic study from the earliest Paleocene Cerros de Montecristo Quartz Monzonite and its Jurassic to uppermost Cretaceous host rock (northern Chile, ˜22°S) provided high-temperature, high-coercivity magnetizations of dominantly reversed polarity. The remanences of the tilted host rock gave a negative fold-test and are indistinguishable from the remanences found in the pluton, indicating that the uppermost Cretaceous rocks underwent deformation before intrusion of the earliest Paleocene pluton, thus documenting a K-T deformation at the locality. Although this deformation may be another product of typical subduction-related noncollisional tectonics in the Central Andes, an alternative hypothesis, permitted by plate reconstructions, is that the event was associated with collision of an oceanic plate boundary. This latter hypothesis may also provide a context for several other tectonic events from northern Chile to the Patagonian Andes, wherein deformation would the consequence of a southward migrating triple junction between the latest Maastrichtian and Early Eocene.

  11. Meloidogyne incognita Inoculum Source Affects Host Suitability and Growth of Yellow Nutsedge and Chile Pepper.

    PubMed

    Thomas, S H; Schroeder, J; Kenney, M J; Murray, L W

    1997-09-01

    Meloidogyne incognita (Mi) reproduction and host plant responses in chile pepper (Capsicum annuum) and yellow nutsedge (Cyperus esculentus = YNS) to three sources of inoculum obtained by rearing a single Mi population on chile, YNS, and tomato were evaluated in two factorial greenhouse experiments. The interactive effects of Mi inoculum source and crop-weed competition were determined. In the absence of YNS competition, chile growth was reduced less by Mi inoculum from chile than by inoculum from YNS or tomato. When YNS was present, chile root weight was not affected and shoot weight increased with Mi initial inoculation, regardless of inoculum source. Chile plants inoculated with Mi from tomato exhibited double the nematode reproduction observed with inoculum from chile or YNS. With chile present, Mi reproduction on YNS was nearly three times greater with inoculum from tomato, but reproduction was similar among inoculum sources when chile was absent. Reductions in YNS root mass due to competition from chile failed to reduce the total number of Mi eggs produced on YNS plants. Differences in total Mi reproduction among inoculum sources were not attributable to differences in root growth or plant competition. This study illustrates the influence of Mi-YNS interactions and previous hosts on severity of Mi infection. PMID:19274174

  12. A new species of Hemipera Nicoll, 1913 (Digenea: Derogenidae) from fishes of the intertidal rocky zone of Chile.

    PubMed

    Díaz, Pablo E; Muñoz, Gabriela; George-Nascimento, Mario

    2016-09-01

    A new species, Hemipera cribbi sp. nov., is described. This trematode was found in three intertidal fish species: Scartichthys viridis (Valenciennes) (Blenniidae), Gobiesox marmoratus Jenyns (Gobiesocidae) and Myxodes viridis Valenciennes (Clinidae) from the central and southern coast of Chile. Of 233 individuals of S. viridis from the central coast examined, 19 were infected. From the southern coast, nine individuals of S. viridis (one infected), five individuals of G. marmoratus (four infected), and 16 individuals of M. viridis (one fish infected) were examined. Hemipera cribbi sp. nov. is distinguished from the five other congeneric species mainly in the body size, being the smallest and narrowest species in the genus, reaching five times longer than wide. This is the first species of the genus described for the South Pacific Ocean off South America. ITS2 rDNA sequences of Hemipera cribbi sp. nov. from each host and locality were identified. PMID:27447214

  13. Uplift and Deformation of the Western Andean Slope, Northernmost Chile: Insights from Deformed Early Miocene Ignimbrites

    NASA Astrophysics Data System (ADS)

    van Zalinge, M. E.; Sparks, R. S. J.; Cooper, F. J.; Evenstar, L.; Aslin, J.; Condon, D. J.

    2015-12-01

    In northern Chile and southern Peru, deformed early Miocene ignimbrites characterize the Western Andean Slope (WAS). In this study we use the emplacement and subsequent deformation of these large-volume ignimbrites to reconstruct the pre-eruptive paleotopography and constrain Miocene uplift rates across the WAS in northernmost Chile. Our results provide evidence that the uplift of the WAS began as early as Eocene-Oligocene time, with elevated rates of uplift during the middle-late Miocene. In northernmost Chile, the WAS is covered by the early Miocene Oxaya Formation (22.7 Ma - 19.6 Ma), a series of ignimbrites and minor sediments that includes the large-volume (>3000 km3), 21.9 Ma Cardones ignimbrite. Following eruption, these ignimbrites were faulted, tilted, and folded into the long-wavelength Huaylillas anticline, which forms a steep slope rising ~2300 m over a distance of ~40 km. Based on the assumption that large-volume ignimbrites like the Cardones infill existing topography to create a relatively uniform low-gradient surface slope of ~1°, we performed a line-balanced reconstruction of this surface. Results suggest the existence of a proto-WAS, with an elevation up to ~1800 m, prior to 21.9 Ma. This proto-WAS had local paleo-lows, in which the Cardones ignimbrite was able to reach thicknesses exceeding 1000 m. We interpret these lows as river valleys that transported sediment from the proto-WAS westwards towards the Central Basin, creating an Eocene-Oligocene (~50-22.7 Ma) clastic wedge, expressed today as the Azapa Formation. After deposition of the Oxaya Formation, the WAS experienced <1° of westward tilting, faulting, and folding resulting in ~2000 m of uplift along the hinge of the Huaylillas anticline. U-Pb geochronology of zircons from intercalated volcanic units in the syn-tectonic Huaylas Basin on the eastern limb of the anticline suggest that the majority of this Miocene uplift occurred between 16 and 6 Ma.

  14. Transit time of water discharges from catchments in coastal mountain of Chile

    NASA Astrophysics Data System (ADS)

    Bustamante-Ortega, Ramon; Morgenstern, Uwe; Ramirez de Arellano, Pablo

    2015-04-01

    Water quantity and quality response of forest catchments to climate and land-use change are difficult to understand and predict due to complexities of subsurface water flow paths. The main focus of forest hydrology in Chile has been the effect of canopy and soil together with rain in water availability. Groundwater, as a factor in water availability especially during dry season, has not been studied. Only a few studies have been carried out in northern Chile in a non-forestry area using the stable isotopes of the water to characterize recharge and depletion of the aquifer. We use tritium for understanding the dynamics of groundwater through small watersheds over a latitudinal gradient in the coastal range of Central Chile. The zone constitutes rapid growth plantations and a large population that depend on surface water and groundwater for drinking, agriculture, pasture and industry. The study areas have metamorphic bedrock with a Mediterranean weather, and precipitation ranging from 700-800 mm year-1 in the North (Constitución area) to 2300-2500 mm year-1 in the South (Valdivia area). The watersheds have been forested with Pinus radiata in 2003 and 1990 respectively, and flow stations were installed in 2008 by Forestal Arauco S.A. to identify the forest management impact on the water cycle. Tritium is present in meteoric water and decays through radioactive decay. In groundwater, which is separated from the tritium production source in the atmosphere, the tritium concentration decreases over time and therefore allows for determination of the residence time of the water in the groundwater system, and the lag time between recharge of the water, and discharge into the streams. Preliminary results of rain samples collected in 2014 in Constitución confirm the tritium input estimate that we made using the New Zealand input data from similar latitude, and the IAEA data (http://www-naweb.iaea.org/napc/ih/IHS_resources_gnip.html). The mean residence time of the water in

  15. Agreement between the Government of the Republic of Chile and ESO for establishing a new centre for observation in Chile - ALMA

    NASA Astrophysics Data System (ADS)

    2002-12-01

    On October 21, 2002, the Minister of Foreign Affairs of the Republic of Chile, Mrs. María Soledad Alvear, and the ESO Director General, Dr. Catherine Cesarsky, signed an Agreement that authorizes ESO to establish a new centre for astronomical observation in Chile.

  16. Marine Biodiversity in Juan Fernández and Desventuradas Islands, Chile: Global Endemism Hotspots.

    PubMed

    Friedlander, Alan M; Ballesteros, Enric; Caselle, Jennifer E; Gaymer, Carlos F; Palma, Alvaro T; Petit, Ignacio; Varas, Eduardo; Muñoz Wilson, Alex; Sala, Enric

    2016-01-01

    The Juan Fernández and Desventuradas islands are among the few oceanic islands belonging to Chile. They possess a unique mix of tropical, subtropical, and temperate marine species, and although close to continental South America, elements of the biota have greater affinities with the central and south Pacific owing to the Humboldt Current, which creates a strong biogeographic barrier between these islands and the continent. The Juan Fernández Archipelago has ~700 people, with the major industry being the fishery for the endemic lobster, Jasus frontalis. The Desventuradas Islands are uninhabited except for a small Chilean military garrison on San Félix Island. We compared the marine biodiversity of these islands across multiple taxonomic groups. At San Ambrosio Island (SA), in Desventuradas, the laminarian kelp (Eisenia cokeri), which is limited to Desventuradas in Chile, accounted for >50% of the benthic cover at wave exposed areas, while more sheltered sites were dominated by sea urchin barrens. The benthos at Robinson Crusoe Island (RC), in the Juan Fernández Archipelago, comprised a diverse mix of macroalgae and invertebrates, a number of which are endemic to the region. The biomass of commercially targeted fishes was >2 times higher in remote sites around RC compared to sheltered locations closest to port, and overall biomass was 35% higher around SA compared to RC, likely reflecting fishing effects around RC. The number of endemic fish species was extremely high at both islands, with 87.5% of the species surveyed at RC and 72% at SA consisting of regional endemics. Remarkably, endemics accounted for 99% of the numerical abundance of fishes surveyed at RC and 96% at SA, which is the highest assemblage-level endemism known for any individual marine ecosystem on earth. Our results highlight the uniqueness and global significance of these biodiversity hotspots exposed to very different fishing pressures.

  17. Turbidite paleoseismology along the active continental margin of Chile - Feasible or not?

    NASA Astrophysics Data System (ADS)

    Bernhardt, Anne; Melnick, Daniel; Hebbeln, Dierk; Lückge, Andreas; Strecker, Manfred R.

    2015-07-01

    Much progress has been made in estimating recurrence intervals of great and giant subduction earthquakes using terrestrial, lacustrine, and marine paleoseismic archives. Recent detailed records suggest these earthquakes may have variable recurrence periods and magnitudes forming supercycles. Understanding seismic supercycles requires long paleoseismic archives that record timing and magnitude of such events. Turbidite paleoseismic archives may potentially extend past earthquake records to the Pleistocene and can thus complement commonly shorter-term terrestrial archives. However, in order to unambiguously establish recurring seismicity as a trigger mechanism for turbidity currents, synchronous deposition of turbidites in widely spaced, isolated depocenters has to be ascertained. Furthermore, characteristics that predispose a seismically active continental margin to turbidite paleoseismology and the correct sample site selection have to be taken into account. Here we analyze 8 marine sediment cores along 950 km of the Chile margin to test for the feasibility of compiling detailed and continuous paleoseismic records based on turbidites. Our results suggest that the deposition of areally widespread, synchronous turbidites triggered by seismicity is largely controlled by sediment supply and, hence, the climatic and geomorphic conditions of the adjacent subaerial setting. The feasibility of compiling a turbidite paleoseismic record depends on the delicate balance between sufficient sediment supply providing material to fail frequently during seismic shaking and sufficiently low sedimentation rates to allow for coeval accumulation of planktonic foraminifera for high-resolution radiocarbon dating. We conclude that offshore northern central Chile (29-32.5°S) Holocene turbidite paleoseismology is not feasible, because sediment supply from the semi-arid mainland is low and almost no Holocene turbidity-current deposits are found in the cores. In contrast, in the humid region

  18. Comparative karyotype analysis of populations in the Alstroemeria presliana Herbert (Alstroemeriaceae) complex in Chile.

    PubMed

    Baeza, Carlos; Finot, Víctor L; Ruiz, Eduardo

    2015-05-01

    Alstroemeria L., one of the most diverse genera of the Chilean flora and of high floricultural value, is represented by 35 species, most of them distributed between 28-38° S in the Mediterranean zone of Central Chile. There are 24 complex-forming taxa, of which 18 have conservation problems (8 are considered "endangered" and 10 as "vulnerable"). One of these complexes is Alstroemeria presliana Herb. with two subspecies: subsp. presliana and subsp. australis Bayer. Alstroemeria presliana grows in Chile and Argentina: subsp. presliana is distributed from Reserva Nacional Siete Tazas (35°27' S, Region of Maule) to Antuco, (37°25' S, Region of Bío-Bío), and is also found in Neuquén, Argentina; subsp. australis is endemic to the Cordillera of Nahuelbuta. A comparative karyotype study was carried out among six populations of A. presliana subsp. presliana and five populations of A. presliana subsp. australis. The eleven populations presented an asymmetric karyotype, with 2n = 2× = 16 chromosomes but with different karyotype formulae. A. presliana subsp. presliana shows the haploid formula 2m + 2m-sat + 1sm-sat + 1st-sat + 1t + 1 t-sat, and A. preslianasubsp. australis presents a formula 1m + 2m-sat + 1sm + 2t + 2t-sat chromosomes. The architecture of the karyotype between the subspecies is very different. The scatter plot among CVCL vs. MCA shows different groupings between populations of the two subspecies. According to the results obtained it is possible to consider raising Alstroemeria presliana subsp. australis at species level.

  19. Marine Biodiversity in Juan Fernández and Desventuradas Islands, Chile: Global Endemism Hotspots

    PubMed Central

    Friedlander, Alan M.; Ballesteros, Enric; Caselle, Jennifer E.; Gaymer, Carlos F.; Palma, Alvaro T.; Petit, Ignacio; Varas, Eduardo; Muñoz Wilson, Alex; Sala, Enric

    2016-01-01

    The Juan Fernández and Desventuradas islands are among the few oceanic islands belonging to Chile. They possess a unique mix of tropical, subtropical, and temperate marine species, and although close to continental South America, elements of the biota have greater affinities with the central and south Pacific owing to the Humboldt Current, which creates a strong biogeographic barrier between these islands and the continent. The Juan Fernández Archipelago has ~700 people, with the major industry being the fishery for the endemic lobster, Jasus frontalis. The Desventuradas Islands are uninhabited except for a small Chilean military garrison on San Félix Island. We compared the marine biodiversity of these islands across multiple taxonomic groups. At San Ambrosio Island (SA), in Desventuradas, the laminarian kelp (Eisenia cokeri), which is limited to Desventuradas in Chile, accounted for >50% of the benthic cover at wave exposed areas, while more sheltered sites were dominated by sea urchin barrens. The benthos at Robinson Crusoe Island (RC), in the Juan Fernández Archipelago, comprised a diverse mix of macroalgae and invertebrates, a number of which are endemic to the region. The biomass of commercially targeted fishes was >2 times higher in remote sites around RC compared to sheltered locations closest to port, and overall biomass was 35% higher around SA compared to RC, likely reflecting fishing effects around RC. The number of endemic fish species was extremely high at both islands, with 87.5% of the species surveyed at RC and 72% at SA consisting of regional endemics. Remarkably, endemics accounted for 99% of the numerical abundance of fishes surveyed at RC and 96% at SA, which is the highest assemblage-level endemism known for any individual marine ecosystem on earth. Our results highlight the uniqueness and global significance of these biodiversity hotspots exposed to very different fishing pressures. PMID:26734732

  20. Marine Biodiversity in Juan Fernández and Desventuradas Islands, Chile: Global Endemism Hotspots.

    PubMed

    Friedlander, Alan M; Ballesteros, Enric; Caselle, Jennifer E; Gaymer, Carlos F; Palma, Alvaro T; Petit, Ignacio; Varas, Eduardo; Muñoz Wilson, Alex; Sala, Enric

    2016-01-01

    The Juan Fernández and Desventuradas islands are among the few oceanic islands belonging to Chile. They possess a unique mix of tropical, subtropical, and temperate marine species, and although close to continental South America, elements of the biota have greater affinities with the central and south Pacific owing to the Humboldt Current, which creates a strong biogeographic barrier between these islands and the continent. The Juan Fernández Archipelago has ~700 people, with the major industry being the fishery for the endemic lobster, Jasus frontalis. The Desventuradas Islands are uninhabited except for a small Chilean military garrison on San Félix Island. We compared the marine biodiversity of these islands across multiple taxonomic groups. At San Ambrosio Island (SA), in Desventuradas, the laminarian kelp (Eisenia cokeri), which is limited to Desventuradas in Chile, accounted for >50% of the benthic cover at wave exposed areas, while more sheltered sites were dominated by sea urchin barrens. The benthos at Robinson Crusoe Island (RC), in the Juan Fernández Archipelago, comprised a diverse mix of macroalgae and invertebrates, a number of which are endemic to the region. The biomass of commercially targeted fishes was >2 times higher in remote sites around RC compared to sheltered locations closest to port, and overall biomass was 35% higher around SA compared to RC, likely reflecting fishing effects around RC. The number of endemic fish species was extremely high at both islands, with 87.5% of the species surveyed at RC and 72% at SA consisting of regional endemics. Remarkably, endemics accounted for 99% of the numerical abundance of fishes surveyed at RC and 96% at SA, which is the highest assemblage-level endemism known for any individual marine ecosystem on earth. Our results highlight the uniqueness and global significance of these biodiversity hotspots exposed to very different fishing pressures. PMID:26734732

  1. Comparative karyotype analysis of populations in the Alstroemeria presliana Herbert (Alstroemeriaceae) complex in Chile

    PubMed Central

    Baeza, Carlos; Finot, Víctor L.; Ruiz, Eduardo

    2015-01-01

    Alstroemeria L., one of the most diverse genera of the Chilean flora and of high floricultural value, is represented by 35 species, most of them distributed between 28–38° S in the Mediterranean zone of Central Chile. There are 24 complex-forming taxa, of which 18 have conservation problems (8 are considered “endangered” and 10 as “vulnerable”). One of these complexes is Alstroemeria presliana Herb. with two subspecies: subsp. presliana and subsp. australis Bayer. Alstroemeria presliana grows in Chile and Argentina: subsp. presliana is distributed from Reserva Nacional Siete Tazas (35°27′ S, Region of Maule) to Antuco, (37°25′ S, Region of Bío-Bío), and is also found in Neuquén, Argentina; subsp. australis is endemic to the Cordillera of Nahuelbuta. A comparative karyotype study was carried out among six populations of A. presliana subsp. presliana and five populations of A. presliana subsp. australis. The eleven populations presented an asymmetric karyotype, with 2n = 2× = 16 chromosomes but with different karyotype formulae. A. presliana subsp. presliana shows the haploid formula 2m + 2m-sat + 1sm-sat + 1st-sat + 1t + 1 t-sat, and A. preslianasubsp. australis presents a formula 1m + 2m-sat + 1sm + 2t + 2t-sat chromosomes. The architecture of the karyotype between the subspecies is very different. The scatter plot among CVCL vs. MCA shows different groupings between populations of the two subspecies. According to the results obtained it is possible to consider raising Alstroemeria presliana subsp. australis at species level. PMID:26273223

  2. ESO Delegation to Visit Chile: the Chile-Eso Treaty and Paranal

    NASA Astrophysics Data System (ADS)

    1994-05-01

    The ESO Council, in its extraordinary session on 28 April 1994, among other matters discussed the relations with the Republic of Chile and the situation around Paranal mountain [1], the designated site for the ESO Very Large Telescope (VLT). Council decided to send a high ranking delegation to Santiago de Chile to discuss with Chilean authorities the pending problems, including the finalisation of the new Treaty between the Republic of Chile and ESO and the legal aspects of the Paranal location. The ESO delegation will consist of Dr. Peter Creola (President of ESO Council), Dr. Catherine Cesarsky (Vice-President of ESO Council), Dr. Henrik Grage (Former Vice-President of ESO Council) and Professor Riccardo Giacconi (ESO Director General), the latter accompanied by his advisers. The delegation will arrive in Chile during the second half of May 1994. The ESO delegation will meet with the Chilean Minister of Foreign Affairs, Mr. Carlos Figueroa, and the Secretary of State in the Ministry of Foreign Affairs, Mr. Jose Miguel Insulza. Other meetings at high level are being planned. The delegation will report about these discussions to the ESO Council during its ordinary session on 7 - 8 June 1994. FOUR PARANAL PHOTOS AVAILABLE A series of four photos which show the current status of the work at Paranal has been prepared. Photographic colour prints for use by the media can be requested from the ESO Information and Photographic Service (please remember to indicate the identification numbers). [1] See ESO Press Release 07/94 of 21 April 1994. PHOTO CAPTIONS ESO PR PHOTO 08/94-1: CERRO PARANAL This aerial photo of the Paranal mountain, the designated site for the ESO Very Large Telescope (VLT), was obtained on 22 March 1994. Paranal is situated in the driest part of the Chilean Atacama desert, approx. 130 km south of the city of Antofagasta, and about 12 km from the Pacific Ocean. In this view towards the West, the ocean is seen in the background. The altitude is 2650 metres

  3. A new titanosaur sauropod from the Atacama Desert, Chile.

    PubMed

    Kellner, Alexander W A; Rubilar-Rogers, David; Vargas, Alexander; Suárez, Mario

    2011-03-01

    Partial remains of a titanosaur sauropod collected in the Tolar Formation (Upper Cretaceous) at the Atacama Desert (Antofagasta Region), northern Chile, is described, and a new species, Atacamatitan chilensis gen. et sp. nov., is erected. The material consists mainly of dorsal and caudal vertebrae, part of a humerus and a femur. The presence of a titanosaur confirms the Cretaceous age for the outcrops of red sandstone of the Tolar Formation whose age was previously uncertain, ranging from the Upper Cretaceous to the Paleocene. The new specimen represents the most complete dinosaur reported for this region and one of the most complete titanosaur known from Chile and the pacific margin of South America so far. PMID:21437382

  4. A new titanosaur sauropod from the Atacama Desert, Chile.

    PubMed

    Kellner, Alexander W A; Rubilar-Rogers, David; Vargas, Alexander; Suárez, Mario

    2011-03-01

    Partial remains of a titanosaur sauropod collected in the Tolar Formation (Upper Cretaceous) at the Atacama Desert (Antofagasta Region), northern Chile, is described, and a new species, Atacamatitan chilensis gen. et sp. nov., is erected. The material consists mainly of dorsal and caudal vertebrae, part of a humerus and a femur. The presence of a titanosaur confirms the Cretaceous age for the outcrops of red sandstone of the Tolar Formation whose age was previously uncertain, ranging from the Upper Cretaceous to the Paleocene. The new specimen represents the most complete dinosaur reported for this region and one of the most complete titanosaur known from Chile and the pacific margin of South America so far.

  5. Trust via disasters: the case of Chile's 2010 earthquake.

    PubMed

    Dussaillant, Francisca; Guzmán, Eugenio

    2014-10-01

    Chile has a long-standing history of natural disasters and, in particular, earthquakes. The latest big earthquake hit Chile on 27 February 2010 with a magnitude of 8.8 on the Richter scale. As an event that had a profound impact on significant portions of the population, the earthquake could theoretically have served to build trust by promoting new trust networks through the enhancement of distant family ties and the interaction between affected neighbours. This study offers an empirical analysis of this theory in the Chilean case. It finds that if initial social capital is very low (thus allowing for post-disaster looting and violence), then the impact of the trust-increasing effect is smaller. It also shows that the effect of the disaster was not transitory, but that it persisted and actually increased over time. PMID:25196338

  6. [Two new genera of land snails (Stylommatophora: Arionacea) from Chile].

    PubMed

    Vargas-Almonacid, Patricio; Stuardo, José R

    2007-06-01

    We describe two new genera of land molluscs found under wet leaf litter in isolated fragments of a secondary native forest at the Hualpén Botanical Park (36 degrees 45'-36 degrees 49' S, 73 degrees 9'-73 degrees 13' W), University of Concepción, Chile. The new taxa are Pichikadi gen.n., of Punctidae, and Chellius gen.n., of Charopidae, with the following new species: Pichikadi hualpensis sp.n., and Chellius piramidalis sp.n. English diagnosis are presented for all taxa, together with an English identification key and English versions of figure captions and table headings. To facilitate subsequent studies and interpretations, we follow recent authors in using mainly shell characters, an approach that has favored the present taxonomic stability of the world's land micromollusca. The diagnosis and observations are complemented with a key for the species of these families inhabiting continental Chile.

  7. [Chile: political education and a critical reading of television].

    PubMed

    Mattelart, M

    1979-01-01

    A study of television was conducted in Chile in 1971. There is a discontinuous aspect in the requests of the public, especially in times of crisis and rupture with the traditional order. In order to measure the various levels of appreciation and critique raised by the television in various areas of the working class in Chile, the poblaciones (peripheric residential zones) were chosen as the place for the study. 100 interviews were conducted. 60% of the people questioned were sympathizers or militants of the various left wing parties; the other 40% were sympathizers or militants of the opposition (Christian democracy, National party and right wing of the radical party). Television does not make any distinction between the publics, but the public makes distinctions between the effects of television. Melodramas and detective programs have the largest adhesion in the popular public of Latin America. PMID:12261387

  8. Biosecurity practices on intensive pig production systems in Chile.

    PubMed

    Julio Pinto, C; Santiago Urcelay, V

    2003-06-12

    Chile eradicated classical swine fever (CSF) in April 1998, following a 17-year eradication programme. The authors describe biosecurity levels of pig farms in Chile after the eradication of CSF. A formal survey was administered to 50 large integrated pig farms, which represented almost 60% of the swine population. The main topics on the questionnaire were production, health management, biosecurity, insurance and information about CSF outbreaks in the past. Biosecurity practices were analysed according to the criteria stated by Barcelo and Marco in 1998. A scoring system to measure biosecurity was designed and pig farms were classified according to this score. An adjusted specific measure is discussed as a potential indicator of risk for disease infections. The authors explore associations between biosecurity herd size and insurance policy against CSF.

  9. Trust via disasters: the case of Chile's 2010 earthquake.

    PubMed

    Dussaillant, Francisca; Guzmán, Eugenio

    2014-10-01

    Chile has a long-standing history of natural disasters and, in particular, earthquakes. The latest big earthquake hit Chile on 27 February 2010 with a magnitude of 8.8 on the Richter scale. As an event that had a profound impact on significant portions of the population, the earthquake could theoretically have served to build trust by promoting new trust networks through the enhancement of distant family ties and the interaction between affected neighbours. This study offers an empirical analysis of this theory in the Chilean case. It finds that if initial social capital is very low (thus allowing for post-disaster looting and violence), then the impact of the trust-increasing effect is smaller. It also shows that the effect of the disaster was not transitory, but that it persisted and actually increased over time.

  10. Typing of the rabies virus in Chile, 2002-2008.

    PubMed

    Yung, V; Favi, M; Fernandez, J

    2012-12-01

    In Chile, dog rabies has been controlled and insectivorous bats have been identified as the main rabies reservoir. This study aimed to determine the rabies virus (RABV) variants circulating in the country between 2002 and 2008. A total of 612 RABV isolates were tested using a panel with eight monoclonal antibodies against the viral nucleoprotein (N-mAbs) for antigenic typing, and a product of 320-bp of the nucleoprotein gene was sequenced from 99 isolates. Typing of the isolates revealed six different antigenic variants but phylogenetic analysis identified four clusters associated with four different bat species. Tadarida brasiliensis bats were confirmed as the main reservoir. This methodology identified several independent rabies enzootics maintained by different species of insectivorous bats in Chile. PMID:22458941

  11. [Mental health financing in Chile: a pending debt].

    PubMed

    Errázuriz, Paula; Valdés, Camila; Vöhringer, Paul A; Calvo, Esteban

    2015-09-01

    In spite of the high prevalence of mental health disorders in Chile, there is a significant financing deficit in this area when compared to the world's average. The financing for mental health has not increased in accordance with the objectives proposed in the 2000 Chilean National Mental Health and Psychiatry Plan, and only three of the six mental health priorities proposed by this plan have secure financial coverage. The National Health Strategy for the Fulfilment of Health Objectives for the decade 2011-2020 acknowledges that mental disorders worsen the quality of life, increase the risk of physical illness, and have a substantial economic cost for the country. Thus, this article focuses on the importance of investing in mental health, the cost of not doing so, and the need for local mental health research. The article discusses how the United States is trying to eliminate the financial discrimination suffered by patients with mental health disorders, and concludes with public policy recommendations for Chile.

  12. [Public health infrastructure investment difficulties in Chile: concessions and public tenders].

    PubMed

    Goyenechea, Matías

    2016-01-01

    This paper seeks to highlight the problems of gaps in health infrastructure in Chile, and to analyze the mechanisms by which it is provided. In Chile this is done in two ways: the first is through competitive bidding or sector-wide modality. The second way is through hospital concessions. Both mechanisms have had difficulties in recent years, which are reported. Finally, we propose ways to improve the provision of health infrastructure in Chile.

  13. Recovery of Durvillaea antarctica (Durvilleales) inside and outside Las Cruces Marine Reserve, Chile.

    PubMed

    Castilla, J C; Campo, M A; Bustamante, R H

    2007-07-01

    We present the results for over two decades of monitoring on intertidal food-gatherers and the population of the low rocky shore dweller kelp Durvillaea antarctica, a short-distance disperser, inside and outside the no-take marine reserve, Estacion Costera de Investigaciones Marinas (ECIM), at Las Cruces, central Chile. It was hypothesized that protection of an initially extremely depleted population would recover by recolonizing first the no-take area and then adjacent non-protected (exploited) areas. We found that recovery of D. antarctica occurred slowly inside ECIM, with increase in density and biomass, of up to three orders of magnitude as compared to an adjacent non-protected area, which showed approximately 2-yr delay. These results suggest that the kelp population inside ECIM was likely regulated via intraspecific competition, which did not occur outside. Results showed no evidence for juvenile vs. adult density dependence other than a weak relationship for the central area of ECIM. These findings also suggest that the population recovery and cross-boundary seeding subsides affected the population dynamics. Understanding these dynamics may enhance management and conservation policies. Our work highlights the critical value of baseline and long-term comparative studies in marine no-take protected and non-protected areas for understanding how population processes respond to human and conservation practices.

  14. Water resources investigation program for Rio Aconcagua Valley, Chile

    USGS Publications Warehouse

    Moore, John Ezra

    1969-01-01

    This report, prepared at the request of the Government of Chile under the auspices of the U. S. Agency for International Development (US AID), is based on a 2-month assignment (Oct. 22 to Dec. 31, 1969) of the author and outlines a program of water resources studies. The study program, if followed to its conclusion, will provide the basic hydrologic and hydrogeologic information and analysis essential for planning optimum future development and use of the water resources of the valley.

  15. [Female migrant workers in Santiago, Chile, during the 1980s].

    PubMed

    Szasz, I

    1992-01-01

    The author examines the status of female migrant workers in Santiago, Chile, in the 1980s, with a focus on the level of poverty and social inequalities. Aspects considered include "the dramatic transformation in domestic service, the increase in the number of non-migrant, lower class women participating in the economy, and the limited and precarious status of women's employment in the more dynamic sectors of the economy." (SUMMARY IN ENG)

  16. Detection of dengue virus type 4 in Easter Island, Chile.

    PubMed

    Fernández, J; Vera, L; Tognarelli, J; Fasce, R; Araya, P; Villagra, E; Roos, O; Mora, J

    2011-10-01

    We report the detection of dengue virus type 4 (DENV-4) for the first time in Easter Island, Chile. The virus was detected in serum samples of two patients treated at the Hospital in Easter Island. The two samples were IgM positive, and the infection was confirmed by RT-PCR and genetic sequencing; viral isolation was possible with one of them. The Easter Island isolates were most closely related to genotype II of dengue type 4.

  17. Unintended pregnancy and sex education in Chile: a behavioural model.

    PubMed

    Herold, J M; Thompson, N J; Valenzuela, M S; Morris, L

    1994-10-01

    This study analysed factors associated with unintended pregnancy among adolescent and young adult women in Santiago, Chile. Three variations of a behavioural model were developed. Logistic regression showed that the effect of sex education on unintended pregnancy works through the use of contraception. Other significant effects were found for variables reflecting socioeconomic status and a woman's acceptance of her sexuality. The results also suggested that labelling affects measurement of 'unintended' pregnancy. PMID:7983095

  18. [Early detection of cervical cancer in Chile: time for change].

    PubMed

    Léniz Martelli, Javiera; Van De Wyngard, Vanessa; Lagos, Marcela; Barriga, María Isabel; Puschel Illanes, Klaus; Ferreccio Readi, Catterina

    2014-08-01

    Mortality rates for cervical cancer (CC) in Chile are higher than those of developed countries and it has an unequal socioeconomic distribution. The recognition of human papilloma virus (HPV) as the causal agent of cervical cancer in the early 80's changed the prevention paradigms. Current goals are to prevent HPV infection by vaccination before the onset of sexual activity and to detect HPV infection in women older than 30 years. This article reviews CC prevention and early detection methods, discusses relevant evidence to support a change in Chile and presents an innovation proposal. A strategy of primary screening based on HPV detection followed by triage of HPV-positive women by colposcopy in primary care or by cytological or molecular reflex testing is proposed. Due to the existence in Chile of a well-organized nationwide CC prevention program, the replacement of a low-sensitivity screening test such as the Papanicolau test with a highly sensitive one such as HPV detection, could quickly improve the effectiveness of the program. The program also has a network of personnel qualified to conduct naked-eye inspections of the cervix, who could easily be trained to perform triage colposcopy. The incorporation of new prevention strategies could reduce the deaths of Chilean women and correct inequities.

  19. Arsenic exposure and its impact on health in Chile.

    PubMed

    Ferreccio, Catterina; Sancha, Ana María

    2006-06-01

    The problem of arsenic in Chile was reviewed. In Chile, the population is exposed to arsenic naturally via drinking-water and by air pollution resulted from mining activities. The sources of arsenic were identified to estimate the exposure of population to arsenic through air, water, and food. Health effects, particularly early effects, observed in children and adults, such as vascular diseases (premature cardiac infarct), respiratory illnesses (bronchiectasis), and skin lesions have been described. Chronic effects, such as lung and bladder cancers, were reported 20 years after peak exposure and persisted 27 years after mitigation measures for removing arsenic from drinking surface water were initiated. Although the effects of arsenic are similar in different ethnic and cultural groups (e.g. Japanese, Chinese, Indian, Bangladeshi, American, and Taiwanese), variations could be explained by age at exposure, the dose received, smoking, and nutrition. Since health effects were observed at arsenic levels of 50 microg/L in drinking-water, it is advised that Chile follows the World Health Organization's recommendation of 10 microg/L. The Chilean experience in removal of arsenic suggests that it is feasible to reach this level using the conventional coagulation process. PMID:17195557

  20. Revisiting the Source Process of the 2007 Tocopilla, Chile Earthquake

    NASA Astrophysics Data System (ADS)

    Simons, M.; Minson, S. E.; Jolivet, R.; Jiang, J.; Beck, J. L.

    2013-12-01

    We revisit the 2007 Mw 7.7 Tocopilla, Chile earthquake to create a finite fault kinematic source model based on the current best practices in data analysis and inversion methods. The data used to constrain the source model include both static GPS offsets and 1 Hz kinematic GPS time series, as well as interferograms which have been reanalyzed to remove tropospheric effects which can be quite significant in this region. Our inversion methodology is a Bayesian approach that uses only physics-based constraints on the rupture evolution, and which utilizes models of both the observational noise and the errors in our forward model to obtain the ensemble of all plausible rupture models which satisfy both the data and our a priori assumptions. This approach allows us to better understand which parts of the rupture process are well-constrained and which are not, and thus to better understand how the 2007 Tocopilla, Chile earthquake rupture fits into the sequence of large earthquakes which have been mosaicking the northern Chile subduction zone.

  1. Arsenic exposure and its impact on health in Chile.

    PubMed

    Ferreccio, Catterina; Sancha, Ana María

    2006-06-01

    The problem of arsenic in Chile was reviewed. In Chile, the population is exposed to arsenic naturally via drinking-water and by air pollution resulted from mining activities. The sources of arsenic were identified to estimate the exposure of population to arsenic through air, water, and food. Health effects, particularly early effects, observed in children and adults, such as vascular diseases (premature cardiac infarct), respiratory illnesses (bronchiectasis), and skin lesions have been described. Chronic effects, such as lung and bladder cancers, were reported 20 years after peak exposure and persisted 27 years after mitigation measures for removing arsenic from drinking surface water were initiated. Although the effects of arsenic are similar in different ethnic and cultural groups (e.g. Japanese, Chinese, Indian, Bangladeshi, American, and Taiwanese), variations could be explained by age at exposure, the dose received, smoking, and nutrition. Since health effects were observed at arsenic levels of 50 microg/L in drinking-water, it is advised that Chile follows the World Health Organization's recommendation of 10 microg/L. The Chilean experience in removal of arsenic suggests that it is feasible to reach this level using the conventional coagulation process.

  2. [Mortality in Chile 1955-1975: trends and causes].

    PubMed

    Taucher, E

    1978-12-01

    Sources for data on mortality in Chile are available from the Instituto National de Estadistica, and from the Servicio National de Salud. For the purpose of this study every possible effort was made to get valid data, relying on the national death register, and on medical certificates of death. Between 1953 and 1963 the mortality rate was 12-13/1000; it abruptly descended in 1973, and rose again, to reach the level of 7.2/1000 in 1975. Male mortality is higher than female mortality. In the years 1974-1975 the mortality rate descended considerably for infants and for children 1-4. If one compares mortality rates in Chile and Sweden for 1975, it is obvious that modern medical technology and different sanitary conditions are responsible for the low mortality rate in Sweden. As to the causes of mortality, 9 diseases are responsible for more than 90% of deaths. During the past 15 years death from cancer was about 110/1000, while violent deaths and deaths by accidents augmented. The death rate for respiratory diseases decreased significantly in 1974-1975. In comparing causes of death in Chile and in the U.S. one notices that respiratory diseases, infectious diseases, and circulatory diseases account for a great number of deaths in Chile, while in the U.S. accidents account for 73.4% of deaths in the 15-24 year old group. Tuberculosis, which has almost disappeared in the U.S., accounts for 5% of deaths in Chile in the 15-44 year old group. Such differences are due to cultural, social and economic diversity in the structure of the 2 countries. Pneumonia still accounts for 50% of infant mortality, and malnutrition for about 39% of mortality of children under 5. Still, most causes of death, like diarrhea in children, could be avoided with proper diagnosis and treatment. Nutrition, sanitary conditions, medical attention, and socioeconomic conditions are finally responsible if Chilean mortality rates still are much higher than those of developed countries.

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

    USGS Publications Warehouse

    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.

  4. Fragmentary evidence of great-earthquake subsidence during holocene emergence, Valdivia estuary, South Central Chile

    USGS Publications Warehouse

    Nelson, A.R.; Kashima, K.; Bradley, L.-A.

    2009-01-01

    A reconnaissance of Holocene stratigraphy beneath fringing marshes of the Valdivia estuary, where an M 9.5 earthquake caused 1-2 m of regional coseismic subsidence in 1960, shows only fragmentary evidence of prehistoric coseismic subsidence. In most of the 150 hand-driven cores that were examined, a distinct unconformity separates 0.5-1.5 m of late Holocene tidal and floodplain mud, peat, and sand from underlying middle Holocene subtidal mud and sand. At the Las Coloradas site, where stratigraphy is best preserved, two A horizons of marsh and meadow soils abruptly overlain by sand and mud probably record coseismic subsidence shortly followed by tsunamis. The amount of subsidence during the earthquakes proved difficult to reconstruct with a diatom transfer function because of differences between modern and fossil diatom assemblages. Maximum 14C ages on macrofossils from the two A horizons at the Las Coloradas site of 1.7-1.3 ka and 2.7-1.7 ka allow correlation of the younger horizon with either of two of six 14C-dated A horizons buried by tsunami sand or post-tsunami tidal sand 200 km to the south at Maull??n, and with a lake-wide mass wasting event in Lago Puyehue, 100 km to the southeast. Tidal records of prehistoric coseismic subsidence at Valdivia are scarce because of a sea-level fall of 3-8 m over the past 6000 years, erosion of marsh and meadow soils during subsidence-induced flooding of the estuary, and largely complete land-level recovery during cycles of coseismic subsidence and postseismic uplift.

  5. Pathways of carbon oxidation in continental margin sediments off central Chile.

    PubMed

    Thamdrup, B; Canfield, D E

    1996-12-01

    Rates and oxidative pathways of organic carbon mineralization were determined in sediments at six stations on the shelf and slope off Concepcion Bay at 36.5 degrees S. The depth distribution of C oxidation rates was determined to 10 cm from accumulation of dissolved inorganic C in 1-5-d incubations. Pathways of C oxidation were inferred from the depth distributions of the potential oxidants (O2, NO3-, and oxides of Mn and Fe) and from directly determined rates of SO4(2-) reduction. The study area is characterized by intense seasonal upwelling, and during sampling in late summer the bottom water over the shelf was rich in NO3- and depleted of O2. Sediments at the four shelf stations were covered by mats of filamentous bacteria of the genera Thioploca and Beggiatoa. Carbon oxidation rates at these sites were extremely high near the sediment surface (>3 micromol cm-3 d-1) and decreased exponentially with depth. The process was entirely coupled to SO4(2-) reduction. At the two slope stations where bottom-water O2 was > 100 microM, C oxidation rates were 10-fold lower and varied less with depth; C oxidation coupled to the reduction of O2, NO3-, and Mn oxides combined to yield an estimated 15% of the total C oxidation between 0 and 10 cm. Carbon oxidation through Fe reduction contributed a further 12-29% of the depth-integrated rate, while the remainder of C oxidation was through SO4(2-) reduction. The depth distribution of Fe reduction agreed well with the distribution of poorly crystalline Fe oxides, and as this pool decreased with depth, the importance of SO4(2-) reduction increased. The results point to a general importance of Fe reduction in C oxidation in continental margin sediments. At the shelf stations, Fe reduction was mainly coupled to oxidation of reduced S. These sediments were generally H2S-free despite high SO4(2-) reduction rates, and precipitation of Fe sulfides dominated H2S scavenging during the incubations. A large NO3- pool was associated with the Thioploca, and the shelf sediments were thus enriched in NO3- relative to the bottom water, with maximum concentrations of 3 micromol cm-3. The NO3- was consumed during our sediment incubations, but no effects on either C or S cycles could be discerned.

  6. Late magmatic stage of the zoned Caleu pluton (Central Chile): insights from zircon crystallization conditions

    NASA Astrophysics Data System (ADS)

    Molina, P. G.; Parada, M.; Gutierrez, F. J.; Chang-Qiang, M.; Jianwei, L.; Yuanyuan, L.

    2012-12-01

    The Caleu pluton consists of three N-S elongated lithological zones: Gabbro-Diorite Zone (GDZ), Tonalite Zone (TZ) and Granodiorite Zone (GZ); western, middle and eastern portions of the pluton, respectively. The zones are thought to be previously differentiated in a common, isotopically depleted (Sr-Nd), subjacent magma reservoir at a 4 kbar equivalent depth. The emplacement should have occurred at the climax of the Cretaceous rifting. We present preliminary results of U238/Pb206 zircon geochronology; zircon saturation, Tsat(Zrn), and crystallization temperatures (Ti-in-Zrn); as well as relative oxidation states at time of crystallization, based on: (i) the sluggish REE and HFSE subsolidus diffusivities in zircon; (ii) the behavior of Ti4+↔Si4+ and Ce4+↔Zr4+ isovalent replacement, in addition to a constrained TiO2 activity in almost all typical crustal rocks; and (iii) relative oxidation states at time of crystallization, respectively. The latter are obtained by interpolation of the partition coefficients of trivalent (REE) and tetravalent (HFSE) curves in Onuma diagrams for each zircon, and then estimating relative Ce(IV)/Ce(III) ratios. Results obtained from 4 samples (a total of 77 zircon grains) collected from the three mentioned lithological zones indicate U/Pb ages of approximately 99.5 ±1.5 Ma, 96.8 ±0.6 Ma, and 94.4 +2.2 -0.8 Ma; and Ti-in Zrn ranges of ca. 720-870°C, ca. 680-820°C and ca. 750-840°C, for the GDZ, TZ and GZ samples, respectively. On the other hand Tsat(Zrn) of ca. 750-780°C in the TZ, and ca. 830-890°C in the GZ, were obtained. As expected saturation temperatures are similar or higher than Ti-in-Zrn obtained in zircon grains of TZ and GZ, respectively. Cathodoluminiscence images in zircon suggest a magmatic origin, due to absence of complex zoning patterns and fairly well conserved morphologies. Exceptionally the GDZ sample zircons show evidence of inheritance, indicating a xenocrystic and/or antecrystic origin. A relative Ce(IV)/Ce(III) decrease with temperature gives rise to separate trends for each zone, suggesting an independent unbuffered development at time of zircon formation. Taking into account variations in zircon ages, morphologies and crystallization ranges in the collected samples, it is suggested that zircon crystallization took place independent of the magma composition. Furthermore, old inherited zircon grains in the GDZ could be antecrysts, or products of a restricted and not major host rock assimilation, owing to the impossibility of basaltic magmas to saturate zircon crystals, and the isotopically depleted signature. This study is financed by CONICYT-FONDAP grant 15090013, Centro de Excelencia en Geotermia de los Andes (CEGA); and the CONICYT PBCT-PDA07, Programa Bicentenario de Ciencia y Tecnología.

  7. Polybrominated Diphenyl Ethers (PBDEs) in Concepción Bay, central Chile after the 2010 Tsunami.

    PubMed

    Pozo, Karla; Kukučka, Petr; Vaňková, Lenka; Přibylová, Petra; Klánová, Jana; Rudolph, Anny; Banguera, Yulieth; Monsalves, Javier; Contreras, Sergio; Barra, Ricardo; Ahumada, Ramón

    2015-06-15

    PBDEs (10 congeners) were analyzed using GC-MS in superficial sediments and organisms of the Concepción Bay after the 2010 Tsunami. From all congeners analyzed PBDE-47, -99, -100 and -209 were the most frequently detected. Concentrations (ngg(-1) d.w.) in sediments for ΣPBDE-47, -99, -100 were low (0.02-0.09). However, PBDE-209 showed significantly higher values ∼20ngg(-1) d.w. This result were ∼10 times lower than those reported in a previous study of the 2010 Tsunami. The high result might be influenced by the massive urban debris dragged by the 2010 Tsunami. In organisms, concentrations of PBDE-47, -99, -100 (∼0.4ngg(-1) d.w.) were higher than those found in sediments (∼0.04ngg(-1) d.w.). Differences in PBDE pattern were also observed between different levels of the trophic food chain (primary and secondary consumers). This is the first attempt to assess the current status of Concepción Bay after the 2010 Tsunami.

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

    USGS Publications Warehouse

    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.

  9. Polybrominated Diphenyl Ethers (PBDEs) in Concepción Bay, central Chile after the 2010 Tsunami.

    PubMed

    Pozo, Karla; Kukučka, Petr; Vaňková, Lenka; Přibylová, Petra; Klánová, Jana; Rudolph, Anny; Banguera, Yulieth; Monsalves, Javier; Contreras, Sergio; Barra, Ricardo; Ahumada, Ramón

    2015-06-15

    PBDEs (10 congeners) were analyzed using GC-MS in superficial sediments and organisms of the Concepción Bay after the 2010 Tsunami. From all congeners analyzed PBDE-47, -99, -100 and -209 were the most frequently detected. Concentrations (ngg(-1) d.w.) in sediments for ΣPBDE-47, -99, -100 were low (0.02-0.09). However, PBDE-209 showed significantly higher values ∼20ngg(-1) d.w. This result were ∼10 times lower than those reported in a previous study of the 2010 Tsunami. The high result might be influenced by the massive urban debris dragged by the 2010 Tsunami. In organisms, concentrations of PBDE-47, -99, -100 (∼0.4ngg(-1) d.w.) were higher than those found in sediments (∼0.04ngg(-1) d.w.). Differences in PBDE pattern were also observed between different levels of the trophic food chain (primary and secondary consumers). This is the first attempt to assess the current status of Concepción Bay after the 2010 Tsunami. PMID:25963572

  10. The Puelche volcanic field: Extensive Pleistocene rhyolite lava flows in the Andes of central Chile

    USGS Publications Warehouse

    Hildreth, W.; Fierstein, J.; Godoy, E.; Drake, Robert E.; Singer, B.

    1999-01-01

    A remote volcanic field in the rugged headwaters of the Rio Puelche and Rio Invernada (35.8??S) constitutes the largest cluster of Quaternary rhyolite lava flows yet identified in the Andean Southern Volcanic Zone. The Puelche Volcanic Field belongs to an intra-arc belt of silicic magmatic centers that extends, at least, 140 km north-south and lies well east of the volcanic front but nonetheless considerably west of the intraplate extensional fields of basaltic and alkaline centers of pampean Argentina. The authors' mapping has distinguished one shallow intrusive mass of early Pleistocene biotite rhyodacite (70.5% SiO2), 11 eruptive units of mid-Pleistocene high-K biotite-rhyolite lava (71.3-75.6% SiO2), and 4 eruptive units of basaltic andesite (53.95-4.9% SiO2), the conduits of which cut some of the rhyolites. Basal contacts of the rhyolite lava flows (and subjacent pyroclastic precursors) are generally scree covered, but glacial erosion has exposed internal flow structures and lithologic zonation superbly. Thicknesses of individual rhyolite lava flows range from 75 m to 400 m. Feeders for several units are well exposed. Cliff-draping unconformities and intracanyon relationships among the 11 rhyolite units show that the eruptive sequence spanned at least one glacial episode that accentuated the local relief. Lack of ice-contact features suggests, however, that all or most eruptions took place during non-glacial intervals probably between 400 ka and 100 ka. Post-eruptive glacial erosion reduced the rhyolites to several non-contiguous remnants that altogether cover 83 km2 and represent a surviving volume of about 21 km3. Consideration of slopes, lava thicknesses, and paleotopography suggest that the original area and volume were each about three times greater. Phenocryst content of the rhyolites ranges from 1 to 12%, with plagioclase>>biotite>FeTi oxides in all units and amphibole conspicuous in the least silicic. The chemically varied basaltic andesites range from phenocryst-poor to phenocryst-rich, exhibiting large differences in proportions of clinopyroxene, olivine, plagioclase, and xenocrystic quartz. Compositional bimodality of the volcanic field is striking, there being no Quaternary eruptive units having SiO2 contents between 55 and 70%. Major and trace element compositions of the mafic and silicic rocks are nonetheless typical of continental-margin arc suites, not of intracontinental suites. The lack of intermediate eruptive units and the differences between the mafic and rhyolitic lavas in Sr-isotope composition suggest that the rhyolites fractionated from a hybrid parent rather than continuously from basaltic magma. The rhyolites may contain larger contributions of upper-crustal partial melts than do silicic products of the volcanic-front centers 30 km to the west.

  11. Geological impacts and implications of the 2010 tsunami along the central coast of Chile

    USGS Publications Warehouse

    Morton, Robert A.; Gelfenbaum, Guy; Buckley, Mark L.; Richmond, Bruce M.

    2011-01-01

    Geological effects of the 2010 Chilean tsunami were quantified at five near-field sites along a 200 km segment of coast located between the two zones of predominant fault slip. Field measurements, including topography, flow depths, flow directions, scour depths, and deposit thicknesses, provide insights into the processes and morphological changes associated with tsunami inundation and return flow. The superposition of downed trees recorded multiple strong onshore and alongshore flows that arrived at different times and from different directions. The most likely explanation for the diverse directions and timing of coastal inundation combines (1) variable fault rupture and asymmetrical slip displacement of the seafloor away from the epicenter with (2) resonant amplification of coastal edge waves. Other possible contributing factors include local interaction of incoming flow and return flow and delayed wave reflection by the southern coast of Peru. Coastal embayments amplified the maximum inundation distances at two sites (2.4 and 2.6 km, respectively). Tsunami vertical erosion included scour and planation of the land surface, inundation scour around the bases of trees, and channel incision from return flow. Sheets and wedges of sand and gravel were deposited at all of the sites. Locally derived boulders up to 1 m in diameter were transported as much as 400 m inland and deposited as fields of dispersed clasts. The presence of lobate bedforms at one site indicates that at least some of the late-stage sediment transport was as bed load and not as suspended load. Most of the tsunami deposits were less than 25 cm thick. Exceptions were thick deposits near open-ocean river mouths where sediment supply was abundant. Human alterations of the land surface at most of the sites provided opportunities to examine some tsunami effects that otherwise would not have been possible, including flow histories, boulder dispersion, and vegetation controls on deposit thickness.

  12. Geological effects and implications of the 2010 tsunami along the central coast of Chile

    USGS Publications Warehouse

    Morton, R.A.; Gelfenbaum, G.; Buckley, M.L.; Richmond, B.M.

    2011-01-01

    Geological effects of the 2010 Chilean tsunami were quantified at five near-field sites along a 200. km segment of coast located between the two zones of predominant fault slip. Field measurements, including topography, flow depths, flow directions, scour depths, and deposit thicknesses, provide insights into the processes and morphological changes associated with tsunami inundation and return flow. The superposition of downed trees recorded multiple strong onshore and alongshore flows that arrived at different times and from different directions. The most likely explanation for the diverse directions and timing of coastal inundation combines (1) variable fault rupture and asymmetrical slip displacement of the seafloor away from the epicenter with (2) resonant amplification of coastal edge waves. Other possible contributing factors include local interaction of incoming flow and return flow and delayed wave reflection by the southern coast of Peru. Coastal embayments amplified the maximum inundation distances at two sites (2.4 and 2.6. km, respectively). Tsunami vertical erosion included scour and planation of the land surface, inundation scour around the bases of trees, and channel incision from return flow. Sheets and wedges of sand and gravel were deposited at all of the sites. Locally derived boulders up to 1. m in diameter were transported as much as 400. m inland and deposited as fields of dispersed clasts. The presence of lobate bedforms at one site indicates that at least some of the late-stage sediment transport was as bed load and not as suspended load. Most of the tsunami deposits were less than 25. cm thick. Exceptions were thick deposits near open-ocean river mouths where sediment supply was abundant. Human alterations of the land surface at most of the sites provided opportunities to examine some tsunami effects that otherwise would not have been possible, including flow histories, boulder dispersion, and vegetation controls on deposit thickness. ?? 2011.

  13. Evaluation and improvement of the CLIGEN model for storm and rainfall erosivity generation in Central Chile

    Technology Transfer Automated Retrieval System (TEKTRAN)

    CLIGEN (CLImate GENerator) is a stochastic weather generator that produces daily estimates of precipitation and individual storm parameters, including time to peak, peak intensity and storm duration. These parameters are typically used as inputs for other models, such as the Water Erosion Prediction...

  14. Genetic divergence analysis of the Common Barn Owl Tyto alba (Scopoli, 1769) and the Short-eared Owl Asio flammeus (Pontoppidan, 1763) from southern Chile using COI sequence.

    PubMed

    Colihueque, Nelson; Gantz, Alberto; Rau, Jaime Ricardo; Parraguez, Margarita

    2015-01-01

    In this paper new mitochondrial COI sequences of Common Barn Owl Tyto alba (Scopoli, 1769) and Short-eared Owl Asio flammeus (Pontoppidan, 1763) from southern Chile are reported and compared with sequences from other parts of the World. The intraspecific genetic divergence (mean p-distance) was 4.6 to 5.5% for the Common Barn Owl in comparison with specimens from northern Europe and Australasia and 3.1% for the Short-eared Owl with respect to samples from north America, northern Europe and northern Asia. Phylogenetic analyses revealed three distinctive groups for the Common Barn Owl: (i) South America (Chile and Argentina) plus Central and North America, (ii) northern Europe and (iii) Australasia, and two distinctive groups for the Short-eared Owl: (i) South America (Chile and Argentina) and (ii) north America plus northern Europe and northern Asia. The level of genetic divergence observed in both species exceeds the upper limit of intraspecific comparisons reported previously for Strigiformes. Therefore, this suggests that further research is needed to assess the taxonomic status, particularly for the Chilean populations that, to date, have been identified as belonging to these species through traditional taxonomy. PMID:26668551

  15. Genetic divergence analysis of the Common Barn Owl Tyto alba (Scopoli, 1769) and the Short-eared Owl Asio flammeus (Pontoppidan, 1763) from southern Chile using COI sequence.

    PubMed

    Colihueque, Nelson; Gantz, Alberto; Rau, Jaime Ricardo; Parraguez, Margarita

    2015-01-01

    In this paper new mitochondrial COI sequences of Common Barn Owl Tyto alba (Scopoli, 1769) and Short-eared Owl Asio flammeus (Pontoppidan, 1763) from southern Chile are reported and compared with sequences from other parts of the World. The intraspecific genetic divergence (mean p-distance) was 4.6 to 5.5% for the Common Barn Owl in comparison with specimens from northern Europe and Australasia and 3.1% for the Short-eared Owl with respect to samples from north America, northern Europe and northern Asia. Phylogenetic analyses revealed three distinctive groups for the Common Barn Owl: (i) South America (Chile and Argentina) plus Central and North America, (ii) northern Europe and (iii) Australasia, and two distinctive groups for the Short-eared Owl: (i) South America (Chile and Argentina) and (ii) north America plus northern Europe and northern Asia. The level of genetic divergence observed in both species exceeds the upper limit of intraspecific comparisons reported previously for Strigiformes. Therefore, this suggests that further research is needed to assess the taxonomic status, particularly for the Chilean populations that, to date, have been identified as belonging to these species through traditional taxonomy.

  16. Genetic divergence analysis of the Common Barn Owl Tyto alba (Scopoli, 1769) and the Short-eared Owl Asio flammeus (Pontoppidan, 1763) from southern Chile using COI sequence

    PubMed Central

    Colihueque, Nelson; Gantz, Alberto; Rau, Jaime Ricardo; Parraguez, Margarita

    2015-01-01

    Abstract In this paper new mitochondrial COI sequences of Common Barn Owl Tyto alba (Scopoli, 1769) and Short-eared Owl Asio flammeus (Pontoppidan, 1763) from southern Chile are reported and compared with sequences from other parts of the World. The intraspecific genetic divergence (mean p-distance) was 4.6 to 5.5% for the Common Barn Owl in comparison with specimens from northern Europe and Australasia and 3.1% for the Short-eared Owl with respect to samples from north America, northern Europe and northern Asia. Phylogenetic analyses revealed three distinctive groups for the Common Barn Owl: (i) South America (Chile and Argentina) plus Central and North America, (ii) northern Europe and (iii) Australasia, and two distinctive groups for the Short-eared Owl: (i) South America (Chile and Argentina) and (ii) north America plus northern Europe and northern Asia. The level of genetic divergence observed in both species exceeds the upper limit of intraspecific comparisons reported previously for Strigiformes. Therefore, this suggests that further research is needed to assess the taxonomic status, particularly for the Chilean populations that, to date, have been identified as belonging to these species through traditional taxonomy. PMID:26668551

  17. Sylvatic foci of the Chagas disease vector Triatoma infestans in Chile: description of a new focus and challenges for control programs.

    PubMed

    Bacigalupo, Antonella; Torres-Pérez, Fernando; Segovia, Verónica; García, Alejandro; Correa, Juana P; Moreno, Lucila; Arroyo, Patricio; Cattan, Pedro E

    2010-08-01

    Triatoma infestans is one of the main domestic vectors of Chagas disease. Reports of wild habitat occurrences have recently increased. In Chile, after a successful elimination campaign of T. infestans domestic infestation, a sylvatic focus was reported in bromeliads in the metropolitan region. Here, we report a new focus of sylvatic T. infestans inhabiting rock piles in the Valparaíso region in central Chile. All T. infestans captured were nymphal instars living among the stones, which were inhabited by several mammal species, along with the sylvatic triatomine vector Mepraia spinolai. We found a prevalence of infection with Trypanosoma cruzi of 36.54% in T. infestans, similar to the previous report for sylvatic specimens from bromeliads. Sylvatic populations of T. infestans should be studied at different geographic scales to elucidate their role in the maintenance of the sylvatic transmission cycle of T. cruzi and their possible role in threatening the domestic elimination of this vector. This information should be used to re-design the control programs in Chile to avoid the re-establishment of the domestic cycle.

  18. Modelling the spatial-temporal progression of the 2009 A/H1N1 influenza pandemic in Chile.

    PubMed

    Bürger, Raimund; Chowell, Gerardo; Mulet, Pep; Villada, Luis M

    2016-02-01

    A spatial-temporal transmission model of 2009 A/H1N1 pandemic influenza across Chile, a country that spans a large latitudinal range, is developed to characterize the spatial variation in peak timing of that pandemic as a function of local transmission rates, spatial connectivity assumptions for Chilean regions, and the putative location of introduction of the novel virus into the country. Specifically, a metapopulation SEIR (susceptible-exposed-infected-removed) compartmental model that tracks the transmission dynamics of influenza in 15 Chilean regions is calibrated. The model incorporates population mobility among neighboring regions and indirect mobility to and from other regions via the metropolitan central region ('hub region'). The stability of the disease-free equilibrium of this model is analyzed and compared with the corresponding stability in each region, concluding that stability may occur even with some regions having basic reproduction numbers above 1. The transmission model is used along with epidemiological data to explore potential factors that could have driven the spatial-temporal progression of the pandemic. Simulations and sensitivity analyses indicate that this relatively simple model is sufficient to characterize the south-north gradient in peak timing observed during the pandemic, and suggest that south Chile observed the initial spread of the pandemic virus, which is in line with a retrospective epidemiological study. The 'hub region' in our model significantly enhanced population mixing in a short time scale.

  19. Permian marine sedimentation in northern Chile: new paleontological evidence from the Juan de Morales Formation, and regional paleogeographic implications

    NASA Astrophysics Data System (ADS)

    Díaz-Martínez, E.; Mamet, B.; Isaacson, P. E.; Grader, G. W.

    2000-11-01

    Permian marine sedimentary rocks that crop out in northern Chile are closely related to the development of a Late Paleozoic magmatic arc. A study of Upper Paleozoic units east of Iquique (20°S) identified three members within the Juan de Morales Formation, each of which were deposited in a different sedimentary environment. A coarse-grained terrigenous basal member represents alluvial sedimentation from a local volcanic source. A mixed carbonate-terrigenous middle member represents coastal and proximal shallow marine sedimentation during a relative sea-level rise related with a global transgression. Preliminary foraminifer biostratigraphy of this middle member identified a late Early Permian (late Artinskian-Kungurian) highly impoverished nodosarid-geinitzinid assemblage lacking fusulines and algae, which is characteristic of temperate cold waters and/or disphotic zone. The upper fine-grained terrigenous member represents shallow marine siliciclastic sedimentation under storm influence. The Juan de Morales Formation consists of continental, coastal and shallow marine sediments deposited at the active western margin of Gondwana at mid to low latitudes. A revised late Early Permian age and similar paleogeography and sedimentary environments are also proposed for the Huentelauquén Formation and related units of northern and central Chile, Arizaro Formation of northwestern Argentina, and equivalent units of southernmost Peru.

  20. Modelling the spatial-temporal progression of the 2009 A/H1N1 influenza pandemic in Chile.

    PubMed

    Bürger, Raimund; Chowell, Gerardo; Mulet, Pep; Villada, Luis M

    2016-02-01

    A spatial-temporal transmission model of 2009 A/H1N1 pandemic influenza across Chile, a country that spans a large latitudinal range, is developed to characterize the spatial variation in peak timing of that pandemic as a function of local transmission rates, spatial connectivity assumptions for Chilean regions, and the putative location of introduction of the novel virus into the country. Specifically, a metapopulation SEIR (susceptible-exposed-infected-removed) compartmental model that tracks the transmission dynamics of influenza in 15 Chilean regions is calibrated. The model incorporates population mobility among neighboring regions and indirect mobility to and from other regions via the metropolitan central region ('hub region'). The stability of the disease-free equilibrium of this model is analyzed and compared with the corresponding stability in each region, concluding that stability may occur even with some regions having basic reproduction numbers above 1. The transmission model is used along with epidemiological data to explore potential factors that could have driven the spatial-temporal progression of the pandemic. Simulations and sensitivity analyses indicate that this relatively simple model is sufficient to characterize the south-north gradient in peak timing observed during the pandemic, and suggest that south Chile observed the initial spread of the pandemic virus, which is in line with a retrospective epidemiological study. The 'hub region' in our model significantly enhanced population mixing in a short time scale. PMID:26776260

  1. U-Pb and K-Ar geochronology in Paleozoic and Mesozoic intrusive rocks of the Coastal Cordillera, Valparaiso, Chile

    USGS Publications Warehouse

    Gana, Paulina; Tosdal, Richard M.

    1996-01-01

    The U-Pb and K-Ar geochronology applied to intrusive rocks from the Coastal Batholith of Central Chile, demonstrates the existence of a basement block of the Mirasol Unit, with a crystallization age of 299??10 Ma, exposed in the northern block of the Melipilla Fault. The age of 214??1 Ma obtained in the 'Dioritas Gne??isicas de Cartagena Unit', indicates that a Late Triassic magmatism took place in this region; it coincides with the end of an extensive crustal melting period, proposed for northern Chile. The ages of the Jurassic plutonic units (Laguna Verde, Sauce, Pen??uelas and Limache) are restricted to the 156-161 Ma interval, showing in certain cases, inherited zircons from an unknown source. The difference between ages obtained using both chronological methods is a few million years, indicating that a short time passed between the crystallization and the cooling of the plutonic bodies, as well as a fast magmatic differentiation process. The Laguna Verde and Sauce Units, experienced a fast uplift, probably as a result of an extensional tectonic process in the magmatic arc, or induced by the magmatic pressure through fracture zones during Middle Jurassic.

  2. Real-Time Assessment of the 16 September 2015 Chile Tsunami and Implications for Near-Field Forecast

    NASA Astrophysics Data System (ADS)

    Tang, Liujuan; Titov, Vasily V.; Moore, Christopher; Wei, Yong

    2016-02-01

    The magnitude 8.3 earthquake in central Chile on 16 September 2015 and the resulting tsunami severely affected the region, with 15 deaths ( Onemi in Monitoreo por sismo de mayor intensidad. (In Spanish) [Available at: http://www.onemi.cl/alerta/se-declara-alerta-roja-por-sismo-de-mayor-intensidad-y-alarma-de-tsunami/], 2015), over one million evacuated, and flooding in nearby coastal cities. We present our real-time assessment of the 2015 Chile tsunami using the Short-term Inundation Forecasting for Tsunamis system, and post-event analyses with local community models in Chile. We evaluate three real-time tsunami sources, which were inverted at the time that the first quarter-, half-, and full-wave passed the first tsunameter (DART 32402, located approximately 580 km north-northwest of the epicenter), respectively. Measurement comparisons from 26 deep-ocean tsunameters and 38 coastal tide stations show that good model accuracies are achieved for all three sources, particularly for the local sites that recorded the most destructive waves. The study highlights the forecast speed, time and accuracy dependence, and their implications for the local forecast capability. Our analyses suggest that the tsunami's main origination area is about 100-200 km long and 100 km wide, to the north of the earthquake epicenter along the trench and the total estimated tsunami wave energy is 7.9 × 1013 J (with 13 % uncertainty). The study provides important guidelines for the earliest reliable estimate of tsunami energy and local forecasts. They can be obtained with the first quarter-wave of tsunameter recording. These results are also confirmed by a forecast analysis of the 2011 Japan tsunami. Furthermore, we find that the first half-wave tsunameter data are sufficient to accurately forecast the 2015 Chile tsunami, due to the specific orientation between the nearest tsunameter and the source. The study also suggests expanding the operational use of the local community models in real

  3. Preliminary radon measurements at Villarrica volcano, Chile

    NASA Astrophysics Data System (ADS)

    Cigolini, C.; Laiolo, M.; Coppola, D.; Ulivieri, G.

    2013-10-01

    We report data from a radon survey conducted at Villarrica volcano. Measurements have been obtained at selected sites by E-PERM® electrets and two automatic stations utilizing DOSEman detectors (SARAD Gmbh). Mean values for Villarrica are 1600 (±1150) Bq/m3 are similar to values recorded at Cerro Negro and Arenal in Central America. Moderately higher emissions, at measurement sites, were recorded on the NNW sector of the volcano and the summit, ranging from 1800 to 2400 Bq/m3. These measurements indicate that this area could potentially be a zone of flank weakness. In addition, the highest radon activities, up to 4600 Bq/m3, were measured at a station located near the intersection of the Liquiñe-Ofqui Fault Zone with the Gastre Fault Zone. To date, the Villarrica radon measurements reported here are, together with those collected at Galeras (Colombia), the sole radon data reported from South American volcanoes. This research may contribute to improving future geochemical monitoring and volcano surveillance.

  4. Where Are Socioeconomically Deprived Immigrants Located in Chile? A Spatial Analysis of Census Data Using an Index of Multiple Deprivation from the Last Three Decades (1992-2012)

    PubMed Central

    2016-01-01

    Introduction and Purpose of the Study Immigrants in Chile have diverse characteristics and include socioeconomically deprived populations. The location of socioeconomically deprived immigrants is important for the development of public policy intelligence at the local and national levels but their areas of residence have not been mapped in Chile. This study explored the spatial distribution of socioeconomic deprivation among immigrants in Chile, 1992–2012, and compared it to the total population. Material and Methods Areas with socioeconomically deprived populations were identified with a deprivation index which we developed modelled upon the Index of Multiple Deprivation (IMD) for England. Our IMD was based upon the indicators of unemployment, low educational level (primary) and disability from Census data at county level for the three decades 1992, 2002 and 2012, for 332, 339 and 343 counties respectively. We developed two versions of the IMD one based on disadvantage among the total population and another focused upon the circumstances of immigrants only. We generated a spatial representation of the IMD using GIS, for the overall IMD score and for each dimension of the index, separately. We also compared the immigrants´ IMD to the total population´s IMD using Pearson´s correlation test. Results Results showed that socioeconomically deprived immigrants tended to be concentrated in counties in the northern and central area of Chile, in particular within the Metropolitan Region of Santiago. These were the same counties where there was the greatest concentration of socioeconomic deprivation for the total population during the same time periods. Since 1992 there have been significant change in the location of the socioeconomically deprived populations within the Metropolitan Region of Santiago with the highest IMD scores for both the total population and immigrants becoming increasingly concentrated in the central and eastern counties of the Region. Conclusion

  5. 77 FR 70874 - Notification of the Next Meetings of the U.S.-Chile FTA Environmental Affairs Council and ECA...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-27

    ... State. ACTION: Notice of the next meeting of the U.S.-Chile Free Trade Agreement Environmental Affairs... (Environment) of the United States-Chile Free Trade Agreement (``FTA'') and Article II of the United States... Environmental Cooperation; (3) ] Chapter 19 (Environment) of the United States-Chile Free Trade Agreement;...

  6. [History of the University of Chile Faculty of Medicine and clinical hospital location].

    PubMed

    Osorio A, Carlos G

    2015-02-01

    The history of the location of the University of Chile Faculty of Medicine North Campus is derived from a farm of Pedro de Valdivia founder of the city of Santiago de la Nueva Extremadura and governor of the “Reyno de Chile”. This work narrates succinctly the history of this particular location from the Spanish Conquest period to present days.

  7. 75 FR 28059 - Actual Effects of the Free Trade Agreements With Chile, Australia, and Singapore

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-19

    ... COMMISSION Actual Effects of the Free Trade Agreements With Chile, Australia, and Singapore AGENCY: United... Singapore. DATES: July 15, 2010: Deadline for filing written submissions. December 13, 2010: Transmittal of...) concluded with Chile, Singapore, and Australia. In its report the Commission will-- (1) With respect to...

  8. Chile and Its Efforts to Present High-Level Technologies to the Developed World

    ERIC Educational Resources Information Center

    Young, Nathan

    2007-01-01

    Chile is rich in natural resources. Like many other resource-dependent nations, it has never made technology transfer a subject of intense focus. This article sheds light on the technological state of Chile today and its efforts to promote development, increase innovation and move towards a knowledge-based economy. The paper summarizes current…

  9. The Role of the Colegio de Periodistas in the Journalism of Chile.

    ERIC Educational Resources Information Center

    Gardner, Mary A.

    Recent decree laws in Chile, if implemented, will eliminate all professional "colegios" (governing bodies), including those for medicine, law, and journalism, and allow them the alternative of forming free trade unions. The twenty "colegios" of Chile require university education for membership and serve as monitors of the education and ethics…

  10. 75 FR 19658 - Preserved Mushrooms From Chile, China, India, and Indonesia; Determinations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-15

    ..., 2009 (74 FR 50818) and determined on January 4, 2010 that it would conduct expedited reviews (75 FR... COMMISSION Preserved Mushrooms From Chile, China, India, and Indonesia; Determinations On the basis of the... revocation of the antidumping duty orders on preserved mushrooms from Chile, China, India, and...

  11. 75 FR 22369 - Certain Preserved Mushrooms From Chile, India, Indonesia, and the People's Republic of China...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-28

    ... from Indonesia, 64 FR 8310 (February 19, 1999); and Notice of Amendment of Final Determination of Sales... foreseeable time. See Preserved Mushrooms from Chile, China, India, and Indonesia; Determinations, 75 FR 19658...: Certain Preserved Mushrooms from Chile, 63 FR 66529 (December 2, 1998); Notice of Amendment of...

  12. Equity in Education in Chile: The Tensions between Policy and Practice

    ERIC Educational Resources Information Center

    Matear, Ann

    2007-01-01

    The article examines education policy in Chile after the return to democracy in 1990 from an equity perspective. Since then, policies have aimed for continuity, coherence and complementarity with the aim of furthering national development, promoting social mobility, and equitable access to quality education at all levels. However, Chile faces the…

  13. Apprenticeship in Latin America: The INACAP Program in Chile. A Case Study. Occasional Paper #6.

    ERIC Educational Resources Information Center

    Corvalan-Vasquez, Oscar E.

    The development of apprenticeship programs in several Latin American countries was investigated with a focus on the results of an industrial apprenticeship program in Santiago, Chile. The program studied was the Instituto Nacional de Capacitacion Profesional (INACAP), the national vocational training institute of Chile. The purpose of the study…

  14. Barriers to Equitable Access: Higher Education Policy and Practice in Chile Since 1990

    ERIC Educational Resources Information Center

    Matear, Ann

    2006-01-01

    This paper examines higher education policy in Chile after the return to democracy in 1990 from an equity perspective. Chile faces the challenge of implementing equity-oriented policies within the legal confines of an education system constructed under the neoliberal model and introduced by the military government (1973-1990). This has resulted in…

  15. Socio-economic Segregation with (without) Competitive Education Policies: A Comparative Analysis of Argentina and Chile.

    ERIC Educational Resources Information Center

    Narodowski, Mariano; Nores, Milagros

    2002-01-01

    The view that competition initiatives in education, such as Chile's introduction of vouchers, promote socioeconomic segregation in schools is questioned. Chile and Argentina have faced very different decentralization reforms, carried out within different regulatory frameworks, but have arrived at similar situations in terms of schools'…

  16. Vocational Training in Chile: A Decentralized and Market Oriented System. Training Policy Study No. 8.

    ERIC Educational Resources Information Center

    Espinoza, Eduardo Martinez

    From 1976 to 1983 major reforms were enacted in Chile in the vocational training systems, based on four principles: decentralization, integration, diversification, and participation. The vocational training system in Chile is a legally established, market-oriented system in which many private training agencies compete to sell their services to…

  17. Canker and twig dieback of blueberry caused by Pestalotiopsis spp. and a Truncatella sp. in Chile

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Blueberry (Vaccinium spp.) has great economic importance in Chile, currently with about 8,500 ha being cultivated. Recently, the presence of canker and dieback symptoms has been observed along the productive blueberry zone of Chile extending from the V Region (32º49´ South lat.) in the north to the ...

  18. [Preliminary evaluation of Chile's First Citizen Consensus Conference].

    PubMed

    Pellegrini Filho, Alberto; Zurita, Laura

    2004-05-01

    This piece provides an initial assessment of the First Citizen Consensus Conference, an event held in the city of Santiago, Chile, from 22-24 November 2003, on the subject of "The Management of My Medical Record." This conference was the first citizen consensus conference that has been held in Chile as well as the first such conference in Latin America. Consensus conferences were devised by the Danish Board of Technology in 1987 as a way to assess science and technology issues through discussions between experts and a panel of lay persons. At the end of a consensus conference, the lay persons express their opinions and recommendations in a consensus report that is directed at policymakers, decision-makers, and the public in general. The objective of a consensus conference is to bridge the gaps that routinely exist among the general public, experts, and elected officials. So far, the Danish Board of Technology has organized more than 20 of these conferences, using a methodology that has become established as a model. Taking into account the changes that have occurred in the relationship between science and society at large, the Pan American Health Organization has decided to support the holding of consensus conferences in Latin America and the Caribbean. The First Citizen Consensus Conference adapted the Danish methodology to conditions in Chile, and this piece assesses the modifications that were made. In addition, some 6 to 12 months after the conference, there will be an external evaluation of the outcomes and impact of the conference, especially in the communications media, public debate, decision-making, and perceptions of the persons who were involved. Despite the criticisms made in this piece and some shortcomings that are pointed out, the First Citizen Consensus Conference achieved all of its objectives and will serve as an excellent model for similar conferences in other countries of the Americas. PMID:15231085

  19. [Preliminary evaluation of Chile's First Citizen Consensus Conference].

    PubMed

    Pellegrini Filho, Alberto; Zurita, Laura

    2004-05-01

    This piece provides an initial assessment of the First Citizen Consensus Conference, an event held in the city of Santiago, Chile, from 22-24 November 2003, on the subject of "The Management of My Medical Record." This conference was the first citizen consensus conference that has been held in Chile as well as the first such conference in Latin America. Consensus conferences were devised by the Danish Board of Technology in 1987 as a way to assess science and technology issues through discussions between experts and a panel of lay persons. At the end of a consensus conference, the lay persons express their opinions and recommendations in a consensus report that is directed at policymakers, decision-makers, and the public in general. The objective of a consensus conference is to bridge the gaps that routinely exist among the general public, experts, and elected officials. So far, the Danish Board of Technology has organized more than 20 of these conferences, using a methodology that has become established as a model. Taking into account the changes that have occurred in the relationship between science and society at large, the Pan American Health Organization has decided to support the holding of consensus conferences in Latin America and the Caribbean. The First Citizen Consensus Conference adapted the Danish methodology to conditions in Chile, and this piece assesses the modifications that were made. In addition, some 6 to 12 months after the conference, there will be an external evaluation of the outcomes and impact of the conference, especially in the communications media, public debate, decision-making, and perceptions of the persons who were involved. Despite the criticisms made in this piece and some shortcomings that are pointed out, the First Citizen Consensus Conference achieved all of its objectives and will serve as an excellent model for similar conferences in other countries of the Americas.

  20. [The Revista Médica de Chile. 100 years ago].

    PubMed

    Costa-Casaretto, C

    1990-01-01

    Manuel Barros Borgoño MD, Professor of Surgery who graduated in France (1879) was President of the Santiago Medical Society (1885), Dean of the Faculty of Medicine (1889-95) and Rector of the University of Chile (1901). He was a contributor of the Journal. As a prominent surgeon, he introduced different forms of anesthesia, like morphine and atropine, cocaine and methylchloride. He was an organizer of the first Chilean and the first Latin American Medical Congress. In the University he encouraged medical research and helped establish the basic role of the University as a leading institution in the nation. He died in 1903.

  1. [The Revista Médica de Chile. 100 years ago].

    PubMed

    Costa-Casaretto, C

    1990-01-01

    Manuel Barros Borgoño MD, Professor of Surgery who graduated in France (1879) was President of the Santiago Medical Society (1885), Dean of the Faculty of Medicine (1889-95) and Rector of the University of Chile (1901). He was a contributor of the Journal. As a prominent surgeon, he introduced different forms of anesthesia, like morphine and atropine, cocaine and methylchloride. He was an organizer of the first Chilean and the first Latin American Medical Congress. In the University he encouraged medical research and helped establish the basic role of the University as a leading institution in the nation. He died in 1903. PMID:2152709

  2. Panoramic View of the Andes Mountains, Chile and Argentina

    NASA Technical Reports Server (NTRS)

    1992-01-01

    This panoramic view of the Andes Mountains of Chile and Argentina (24.5S, 69.5W) is dominated by the yellows and browns of the coastal Atacama Desert and the full width of the Andes altiplano, about 300 miles. Winter snow can be seen capping the 22,000 to 23,000 ft. peaks of the Andes. Wisps of cirrus clouds lie over the altiplano and offshore fog obscures the coast. In the distance, the low Chaco Plain appears green with pastures and agriculture.

  3. Increasing organ donation by presumed consent and allocation priority: Chile

    PubMed Central

    2015-01-01

    Abstract Chile, a middle-income country, recently joined Israel and Singapore as the world’s only countries to require reciprocity as a precondition for organ transplantation. The Chilean reform includes opt-out provisions designed to foster donation and priority for organ transplantation for registered people. Although the reform has had serious difficulties in achieving its mission, it can be reviewed by other countries that seek to address the serious shortage of organs. As increased organ donation can substantially enhance or save more lives, the effect on organ availability due to incentives arising from rules of preference should not be underestimated. PMID:25767299

  4. Medication Overdoses at a Public Emergency Department in Santiago, Chile

    PubMed Central

    Aguilera, Pablo; Garrido, Marcela; Lessard, Eli; Swanson, Julian; Mallon, William K.; Saldias, Fernando; Basaure, Carlos; Lara, Barbara; Swadron, Stuart P.

    2016-01-01

    Introduction While a nationwide poison control registry exists in Chile, reporting to the center is sporadic and happens at the discretion of the treating physician or by patients’ self-report. Moreover, individual hospitals do not monitor accidental or intentional poisoning in a systematic manner. The goal of this study was to identify all cases of intentional medication overdose (MO) that occurred over two years at a large public hospital in Santiago, Chile, and examine its epidemiologic profile. Methods This study is a retrospective, explicit chart review conducted at Hospital Sótero del Rio from July 2008 until June 2010. We included all cases of identified intentional MO. Alcohol and recreational drugs were included only when they were ingested with other medications. Results We identified 1,557 cases of intentional MO and analyzed a total of 1,197 cases, corresponding to 0.51% of all emergency department (ED) presentations between July 2008 and June 2010. The median patient age was 25 years. The majority was female (67.6%). Two peaks were identified, corresponding to the spring of each year sampled. The rate of hospital admission was 22.2%. Benzodiazepines, selective serotonin reuptake inhibitors, and tricyclic antidepressants (TCA) were the causative agents most commonly found, comprising 1,044 (87.2%) of all analyzed cases. Acetaminophen was involved in 81 (6.8%) cases. More than one active substance was involved in 35% of cases. In 7.3% there was ethanol co-ingestion and in 1.0% co-ingestion of some other recreational drug (primarily cocaine). Of 1,557 cases, six (0.39%) patients died. TCA were involved in two of these deaths. Conclusion Similar to other developed and developing nations, intentional MO accounts for a significant number of ED presentations in Chile. Chile is unique in the region, however, in that its spectrum of intentional overdoses includes an excess burden of tricyclic antidepressant and benzodiazepine overdoses, a relatively low rate

  5. Increasing organ donation by presumed consent and allocation priority: Chile.

    PubMed

    Zúñiga-Fajuri, Alejandra

    2015-03-01

    Chile, a middle-income country, recently joined Israel and Singapore as the world's only countries to require reciprocity as a precondition for organ transplantation. The Chilean reform includes opt-out provisions designed to foster donation and priority for organ transplantation for registered people. Although the reform has had serious difficulties in achieving its mission, it can be reviewed by other countries that seek to address the serious shortage of organs. As increased organ donation can substantially enhance or save more lives, the effect on organ availability due to incentives arising from rules of preference should not be underestimated. PMID:25767299

  6. Increasing organ donation by presumed consent and allocation priority: Chile.

    PubMed

    Zúñiga-Fajuri, Alejandra

    2015-03-01

    Chile, a middle-income country, recently joined Israel and Singapore as the world's only countries to require reciprocity as a precondition for organ transplantation. The Chilean reform includes opt-out provisions designed to foster donation and priority for organ transplantation for registered people. Although the reform has had serious difficulties in achieving its mission, it can be reviewed by other countries that seek to address the serious shortage of organs. As increased organ donation can substantially enhance or save more lives, the effect on organ availability due to incentives arising from rules of preference should not be underestimated.

  7. Phylogeographic Structure in Benthic Marine Invertebrates of the Southeast Pacific Coast of Chile with Differing Dispersal Potential

    PubMed Central

    Haye, Pilar A.; Segovia, Nicolás I.; Muñoz-Herrera, Natalia C.; Gálvez, Francisca E.; Martínez, Andrea; Meynard, Andrés; Pardo-Gandarillas, María C.; Poulin, Elie; Faugeron, Sylvain

    2014-01-01

    The role of dispersal potential on phylogeographic structure, evidenced by the degree of genetic structure and the presence of coincident genetic and biogeographic breaks, was evaluated in a macrogeographic comparative approach along the north-central coast of Chile, across the biogeographic transition zone at 30°S. Using 2,217 partial sequences of the mitochondrial Cytochrome Oxidase I gene of eight benthic invertebrate species along ca. 2,600 km of coast, we contrasted dispersal potential with genetic structure and determined the concordance between genetic divergence between biogeographic regions and the biogeographic transition zone at 30°S. Genetic diversity and differentiation highly differed between species with high and low dispersal potential. Dispersal potential, sometimes together with biogeographic region, was the factor that best explained the genetic structure of the eight species. The three low dispersal species, and one species assigned to the high dispersal category, had a phylogeographic discontinuity coincident with the biogeographic transition zone at 30°S. Furthermore, coalescent analyses based on the isolation-with-migration model validate that the split between biogeographic regions north and south of 30°S has a historic origin. The signatures of the historic break in high dispersers is parsimoniously explained by the homogenizing effects of gene flow that have erased the genetic signatures, if ever existed, in high dispersers. Of the four species with structure across the break, only two had significant albeit very low levels of asymmetric migration across the transition zone. Historic processes have led to the current biogeographic and phylogeographic structure of marine species with limited dispersal along the north-central coast of Chile, with a strong lasting impact in their genetic structure. PMID:24586356

  8. Phylogeographic structure in benthic marine invertebrates of the southeast Pacific coast of Chile with differing dispersal potential.

    PubMed

    Haye, Pilar A; Segovia, Nicolás I; Muñoz-Herrera, Natalia C; Gálvez, Francisca E; Martínez, Andrea; Meynard, Andrés; Pardo-Gandarillas, María C; Poulin, Elie; Faugeron, Sylvain

    2014-01-01

    The role of dispersal potential on phylogeographic structure, evidenced by the degree of genetic structure and the presence of coincident genetic and biogeographic breaks, was evaluated in a macrogeographic comparative approach along the north-central coast of Chile, across the biogeographic transition zone at 30°S. Using 2,217 partial sequences of the mitochondrial Cytochrome Oxidase I gene of eight benthic invertebrate species along ca. 2,600 km of coast, we contrasted dispersal potential with genetic structure and determined the concordance between genetic divergence between biogeographic regions and the biogeographic transition zone at 30°S. Genetic diversity and differentiation highly differed between species with high and low dispersal potential. Dispersal potential, sometimes together with biogeographic region, was the factor that best explained the genetic structure of the eight species. The three low dispersal species, and one species assigned to the high dispersal category, had a phylogeographic discontinuity coincident with the biogeographic transition zone at 30°S. Furthermore, coalescent analyses based on the isolation-with-migration model validate that the split between biogeographic regions north and south of 30°S has a historic origin. The signatures of the historic break in high dispersers is parsimoniously explained by the homogenizing effects of gene flow that have erased the genetic signatures, if ever existed, in high dispersers. Of the four species with structure across the break, only two had significant albeit very low levels of asymmetric migration across the transition zone. Historic processes have led to the current biogeographic and phylogeographic structure of marine species with limited dispersal along the north-central coast of Chile, with a strong lasting impact in their genetic structure. PMID:24586356

  9. Predicting habitat suitability and geographic distribution of anchovy (Engraulis ringens) due to climate change in the coastal areas off Chile

    NASA Astrophysics Data System (ADS)

    Silva, Claudio; Andrade, Isabel; Yáñez, Eleuterio; Hormazabal, Samuel; Barbieri, María Ángela; Aranis, Antonio; Böhm, Gabriela

    2016-08-01

    The effects of climate change on ocean conditions will have impacts on fish stocks, primarily through physiological and behavioural effects, such as changes in growth, reproduction, mortality and distribution. Habitat and distribution predictions for marine fishery species under climate change scenarios are important for understanding the overall impacts of such global changes on the human society and on the ecosystem. In this study, we examine the impacts of climate change on anchovy fisheries off Chile using predicted changes in global models according to the National Centre for Atmospheric Research (NCAR) Community Climate System Model 3.0 (CCSM3) and IPCC high future CO2 emission scenario A2, habitat suitability index (HSI) models and satellite-based sea surface temperature (SST) and chlorophyll-a (Chl-a) estimates from high-resolution regional models for the simulation period 2015-2065. Predictions of SST from global climate models were regionalised using the Delta statistical downscaling technique. Predictions of chlorophyll-a were developed using historical Chl-a and SST (2003-2013) satellite data and applying a harmonic model. The results show an increase in SST of up to 2.5 °C by 2055 in the north and central-south area for an A2 scenario. The habitat suitability index model was developed using historical (2001-2011) monthly fisheries and environmental data. The catch per unit effort (CPUE) was used as an abundance index in developing the HSI models and was calculated as the total catch (ton) by hold capacity (m3) in a 10‧ × 10‧ fishing grid square of anchovy, integrated over one month of fishing activity. The environmental data included the distance to coast (DC), thermal (SST) and food availability (Chl-a) conditions. The HSI modelling consists of estimating SI curves based on available evidence regarding the optimum range of environmental conditions for anchovy and estimating an integrated HSI using the Arithmetic Mean Model (AMM) method. The

  10. Thematic mapper studies of central Andean volcanoes

    NASA Technical Reports Server (NTRS)

    Francis, Peter W.

    1987-01-01

    A series of false color composite images covering the volcanic cordillera was written. Each image is 45 km (1536 x 1536 pixels) and was constructed using bands 7, 4, and 2 of the Thematic Mapper (TM) data. Approximately 100 images were prepared to date. A set of LANDSAT Multispectral Scanner (MSS) images was used in conjunction with the TM hardcopy to compile a computer data base of all volcanic structure in the Central Andean province. Over 500 individual structures were identified. About 75 major volcanoes were identified as active, or potentially active. A pilot study was begun combining Shuttle Imaging Radar (SIR) data with TM for a test area in north Chile and Bolivia.

  11. Grid-wide subdaily hydrologic alteration under massive wind power penetration in Chile.

    PubMed

    Haas, J; Olivares, M A; Palma-Behnke, R

    2015-05-01

    Hydropeaking operations can severely degrade ecosystems. As variable renewable sources (e.g. wind power) are integrated into a power grid, fluctuations in the generation-demand balance are expected to increase. In this context, compensating technologies, notably hydropower reservoir plants, could operate in a stronger peaking scheme. This issue calls for an integrated modeling of the entire power system, including not only hydropower reservoirs, but also all other plants. A novel methodology to study the link between the short-term variability of renewable energies and the subdaily hydrologic alteration, due to hydropower reservoir operations is presented. Grid operations under selected wind power portfolios are simulated using a short-term hydro-thermal coordination tool. The resulting turbined flows by relevant reservoir plants are then compared in terms of the Richard-Baker flashiness index to both the baseline and the natural flow regime. Those are then analyzed in order to: i) detect if there is a significant change in the degree of subdaily hydrologic alteration (SDHA) due to a larger wind penetration, and ii) identify which rivers are most affected. The proposed scheme is applied to Chile's Central Interconnect System (SIC) for scenarios up to 15% of wind energy penetration. Results show a major degree of SDHA under the baseline as compared to the natural regime. As wind power increases, so does the SDHA in two important rivers. This suggests a need for further ecological studies in those rivers, along with an analysis of operational constraints to limit the SDHA. PMID:25728917

  12. A new species of Ornithodoros (Acari: Argasidae) from desert areas of northern Chile.

    PubMed

    Muñoz-Leal, Sebastián; Venzal, José M; González-Acuña, Daniel; Nava, Santiago; Lopes, Marcos G; Martins, Thiago F; Figueroa, Cecilia; Fernández, Nicolás; Labruna, Marcelo B

    2016-07-01

    Ornithodoros atacamensis n. sp. is described from larvae collected on the lizard Liolaemus bisignatus and from free-living adults collected in desert areas from the Pan de Azúcar and Llanos de Challe National Parks, in Northern Chile. Additionally, unengorged larvae were obtained from fertilized females, which laid eggs in the laboratory. Morphological and mitochondrial 16S rDNA sequence analyses were performed in order to compare this new soft tick species with other congeneric Neotropical representatives. Larvae of O. atacamensis are morphologically closely related to Ornithodoros talaje sensu stricto, Ornithodoros puertoricensis, Ornithodoros rioplatensis, Ornithodoros guaporensis and Ornithodoros hasei, all belonging to the O. talaje species group. The larval diagnostic characters for this species are a combination of a large pyriform dorsal plate with a length of approximately 300μm, 17 pairs of dorsal setae with five central pairs, hypostome with apex pointed and dental formula 2/2 in most rows, 3/3 apically, and capsule of the Haller's organ oval in shape without reticulations. Phylogenetic analyses inferred from the mitochondrial 16S rRNA gene and a Principal Component Analysis based on morphometric characters provide additional support to the description of O. atacamensis as an independent lineage within the genus clustering within the O. talaje species group.

  13. Tectonic rotations and internal structure of Eocene plutons in Chuquicamata, northern Chile

    NASA Astrophysics Data System (ADS)

    Somoza, R.; Tomlinson, A. J.; Zaffarana, C. B.; Singer, S. E.; Puigdomenech Negre, C. G.; Raposo, M. I. B.; Dilles, J. H.

    2015-07-01

    A paleomagnetic and AMS study on Eocene plutonic complexes in the Calama area, northern Chile, reveals high-temperature, high-coercivity magnetizations of dominantly thermoremanent origin and magnetic fabrics controlled by magnetite. The paleomagnetic results indicate that ~ 43 Ma plutons underwent clockwise tectonic rotation, whereas adjacent ~ 39 Ma plutons did not undergo discernible rotation. This points to a middle Eocene age for the younger tectonic rotations associated with the Central Andean Rotation Pattern in the Chuquicamata-Calama area. The petrofabric in these rocks formed under conditions ranging from purely magmatic (i.e. before full crystallization) to low-temperature solid-state deformation. AMS and paleomagnetism suggest that the plutonic bodies were formed by progressive amalgamation of subvertical magma sheets spanning multiple magnetic polarity chrons. The parallelism between magmatic and tectonic foliations suggests that regional tectonic stress controlled ascent, emplacement and rock deformation during cooling. In this context, we suggest that magma ascent and emplacement in the upper crust likely exploited Mesozoic structures which were locally reactivated in the Eocene.

  14. New Archaeological Evidence for an Early Human Presence at Monte Verde, Chile

    PubMed Central

    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

  15. Herbivory and seedling performance in a fragmented temperate forest of Chile

    NASA Astrophysics Data System (ADS)

    Simonetti, Javier A.; Grez, Audrey A.; Celis-Diez, Juan L.; Bustamante, Ramiro O.

    2007-11-01

    Forest fragmentation alters plant-animal interactions, including herbivory. Relying manipulative experiments, we test if the reduction in insect herbivory associated with forest fragmentation translates into increased seedling growth and survival of three tree common species ( Aristotelia chilensis, Cryptocarya alba and Persea lingue) in forest fragments and continuous forests in coastal Maulino forest, central Chile. Furthermore, we test if after protecting seedlings from herbivorous insects, plant performance is increased regardless of forest fragmentation. Nursery grown seedlings were transplanted into four forest fragments and a continuous forest during 2002. Insects, important herbivores in this forest, were excluded from half the seedlings by repeated applications of insecticides. Compared to continuous forests, in forest fragments, herbivory was reduced in all three species, seedling growth was greater in A. chilensis and C. alba but not in P. lingue, and survivorship was unaffected by herbivory or fragmentation in all three species. Protecting seedlings from insects reduced herbivory in the continuous forest to similar levels attained in the forest fragments. No change in herbivory results from by protecting seedlings in forest fragments. These results confirm that insects are important herbivores in the Maulino forest and also support the hypothesis that fragmentation can have strong indirect effects on plant communities as mediated through trophic interactions.

  16. Oral health in prehistoric San Pedro de Atacama oases, Northern Chile.

    PubMed

    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.

  17. New Archaeological Evidence for an Early Human Presence at Monte Verde, Chile.

    PubMed

    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

  18. A new species of Ornithodoros (Acari: Argasidae) from desert areas of northern Chile.

    PubMed

    Muñoz-Leal, Sebastián; Venzal, José M; González-Acuña, Daniel; Nava, Santiago; Lopes, Marcos G; Martins, Thiago F; Figueroa, Cecilia; Fernández, Nicolás; Labruna, Marcelo B

    2016-07-01

    Ornithodoros atacamensis n. sp. is described from larvae collected on the lizard Liolaemus bisignatus and from free-living adults collected in desert areas from the Pan de Azúcar and Llanos de Challe National Parks, in Northern Chile. Additionally, unengorged larvae were obtained from fertilized females, which laid eggs in the laboratory. Morphological and mitochondrial 16S rDNA sequence analyses were performed in order to compare this new soft tick species with other congeneric Neotropical representatives. Larvae of O. atacamensis are morphologically closely related to Ornithodoros talaje sensu stricto, Ornithodoros puertoricensis, Ornithodoros rioplatensis, Ornithodoros guaporensis and Ornithodoros hasei, all belonging to the O. talaje species group. The larval diagnostic characters for this species are a combination of a large pyriform dorsal plate with a length of approximately 300μm, 17 pairs of dorsal setae with five central pairs, hypostome with apex pointed and dental formula 2/2 in most rows, 3/3 apically, and capsule of the Haller's organ oval in shape without reticulations. Phylogenetic analyses inferred from the mitochondrial 16S rRNA gene and a Principal Component Analysis based on morphometric characters provide additional support to the description of O. atacamensis as an independent lineage within the genus clustering within the O. talaje species group. PMID:27132517

  19. Oral health in prehistoric San Pedro de Atacama oases, Northern Chile.

    PubMed

    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

  20. Assessing giant tsunamigenic subduction earthquakes in the Northern Chile Seismic Gap during the last two millennia

    NASA Astrophysics Data System (ADS)

    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.

  1. New Archaeological Evidence for an Early Human Presence at Monte Verde, Chile.

    PubMed

    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.

  2. Effects of a copper smelter on a grassland community in the Puchuncaví Valley, Chile.

    PubMed

    Ginocchio, R

    2000-07-01

    A grassland formation has been subjected to pollution generated by the Ventanas copper smelter since 1964 (Puchuncaví Valley, central zone of Chile) with extensive damage to local vegetation and important changes in soil characteristics. The aims of the study were (1) to detect soil parameters that best explain changes observed in plant species richness and abundance and (2) to determine if pollution-derived stresses have also affected regeneration capabilities of plant communities from the soil seed bank. The grassland was quantitatively analysed in terms of physicochemical soil characteristics, plant species diversity and abundance, and soil seed bank species composition and abundance. Results showed that a decrease in total soil nitrogen explained 13% of the changes detected in plant abundance while soil pH and 0.05 M EDTA extractable copper explained 10% and 7%, respectively, of the vegetation change. It was also found that the pollution has already affected plant species regeneration capabilities from the soil seed bank and the microsite distribution of the seeds in soils.

  3. Territorial user rights for fisheries as ancillary instruments for marine coastal conservation in Chile.

    PubMed

    Gelcich, Stefan; Fernández, Miriam; Godoy, Natalio; Canepa, Antonio; Prado, Luis; Castilla, Juan Carlos

    2012-12-01

    Territorial user rights for fisheries have been advocated as a way to achieve sustainable resource management. However, few researchers have empirically assessed their potential as ancillary marine conservation instruments by comparing them to no-take marine protected areas. In kelp (Lessonia trabeculata) forests of central Chile, we compared species richness, density, and biomass of macroinvertebrates and reef fishes among territorial-user-right areas with low-level and high-level enforcement, no-take marine protected areas, and open-access areas in 42 100-m subtidal transects. We also assessed structural complexity of the kelp forest and substratum composition. Multivariate randomized permutation tests indicated macroinvertebrate and reef fish communities associated with the different access regimes differed significantly. Substratum composition and structural complexity of kelp forest did not differ among access regimes. Univariate analyses showed species richness, biomass, and density of macroinvertebrates and reef fishes were greater in highly enforced territorial-user-right areas and no-take marine protected areas than in open-access areas. Densities of macroinvertebrates and reef fishes of economic importance were not significantly different between highly enforced territorial-user-right and no-take marine protected areas. Densities of economically important macroinvertebrates in areas with low-level enforcement were significantly lower than those in areas with high-level enforcement and no-take marine protected areas but were significantly higher than in areas with open access. Territorial-user-right areas could be important ancillary conservation instruments if they are well enforced.

  4. Grid-wide subdaily hydrologic alteration under massive wind power penetration in Chile.

    PubMed

    Haas, J; Olivares, M A; Palma-Behnke, R

    2015-05-01

    Hydropeaking operations can severely degrade ecosystems. As variable renewable sources (e.g. wind power) are integrated into a power grid, fluctuations in the generation-demand balance are expected to increase. In this context, compensating technologies, notably hydropower reservoir plants, could operate in a stronger peaking scheme. This issue calls for an integrated modeling of the entire power system, including not only hydropower reservoirs, but also all other plants. A novel methodology to study the link between the short-term variability of renewable energies and the subdaily hydrologic alteration, due to hydropower reservoir operations is presented. Grid operations under selected wind power portfolios are simulated using a short-term hydro-thermal coordination tool. The resulting turbined flows by relevant reservoir plants are then compared in terms of the Richard-Baker flashiness index to both the baseline and the natural flow regime. Those are then analyzed in order to: i) detect if there is a significant change in the degree of subdaily hydrologic alteration (SDHA) due to a larger wind penetration, and ii) identify which rivers are most affected. The proposed scheme is applied to Chile's Central Interconnect System (SIC) for scenarios up to 15% of wind energy penetration. Results show a major degree of SDHA under the baseline as compared to the natural regime. As wind power increases, so does the SDHA in two important rivers. This suggests a need for further ecological studies in those rivers, along with an analysis of operational constraints to limit the SDHA.

  5. Popular education, work training, and the path to women's empowerment in Chile.

    PubMed

    Bosch, A E

    1998-05-01

    The program 'Educacion y Trabajo' (Education and Work) in Chile was designed to help train unskilled workers and to facilitate their entrance into the labor market. Employing a participatory educational approach, the program provided personal and vocational training for men and women aged 15-30 years. Both technical and personal development training, which are embedded in Popular Education methodology, emphasize interaction among students and between students and teachers using games, videos, slides, manuals, cartoons, and worksheets. Interviews with female participants confirmed the program's empowering effects on the personal, as well as economic situation of women. The study further demonstrates how Popular Education is applied and adapted to promote self-esteem and self-reliance among female participants. Process-oriented, participatory learning, and horizontal relationships between the learner and teacher, allowed for the development of interactive structures in the classroom. This approach has especially benefited married women. Central to this empowerment process is awareness raising. By emphasizing the sociocultural origin of social structures, Popular Education helps demystify the social sphere and shows the importance of each individual in contributing to its improvement. However, while this program helps enhance women's self-esteem, self-confidence, and self-promotion, it only represents an initial step. To continue the path to full empowerment, negotiating powers must go beyond the household level and into the formal economy.

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

    NASA Astrophysics Data System (ADS)

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

    2016-07-01

    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.

  7. Genetic epidemiology of single gene defects in Chile.

    PubMed Central

    Cruz-Coke, R; Moreno, R S

    1994-01-01

    We have studied the correlation between the ethnic structure and the prevalence of single gene defects in Chile. At present the Chilean population is approximately 64% white and 35% Amerindian with traces of other admixture. Fewer than 4% of the Chilean population are foreign born. Investigations indicate that all severe diseases and many others without impaired reproduction have mutation rates within the range of the white population. Classical ethnic diseases are very rare. Autosomal recessive disorders have a wide range of variability: cystic fibrosis has a low incidence and PKU has a similar incidence to English rates. Only 30% of the inborn errors of metabolism have been described in Chilean medical publications. In addition, no Chilean haemoglobin or haptoglobin variants have been described. Some rare inherited diseases in Chilean human isolates have been described, including achromatopsia, chondrocalcinosis, and Creutzfeldt-Jakob disease. The prevalence of intrahepatic cholestasis of pregnancy and supernumerary nipples is the highest in the world and they are associated with aboriginal origin. Single gene defects in Chile are probably shaped by factors related to its ethnic population structure. These local rare single gene defects may be good markers of population admixture for genetic epidemiological studies. PMID:7815439

  8. Abortion in Chile: the practice under a restrictive regime.

    PubMed

    Casas, Lidia; Vivaldi, Lieta

    2014-11-01

    This article examines, from a human rights perspective, the experience of women, and the practices of health care providers regarding abortion in Chile. Most abortions, as high as 100,000 a year, are obtained surreptitiously and clandestinely, and income and connections play a key role. The illegality of abortion correlates strongly with vulnerability, feelings of guilt and loneliness, fear of prosecution, physical and psychological harm, and social ostracism. Moreover, the absolute legal ban on abortion has a chilling effect on health care providers and endangers women's lives and health. Although misoprostol use has significantly helped to prevent greater harm and enhance women's agency, a ban on sales created a black market. Against this backdrop, feminists have taken action in aid of women. For instance, a feminist collective opened a telephone hotline, Linea Aborto Libre (Free Abortion Line), which has been crucial in informing women of the correct and safe use of misoprostol. Chile is at a crossroads. For the first time in 24 years, abortion law reform seems plausible, at least when the woman's life or health is at risk and in cases of rape and fetal anomalies incompatible with life. The political scenario is unfolding as we write. Congressional approval does not mean automatic enactment of a new law; a constitutional challenge is highly likely and will have to be overcome. PMID:25555764

  9. Assessing computer waste generation in Chile using material flow analysis.

    PubMed

    Steubing, Bernhard; Böni, Heinz; Schluep, Mathias; Silva, Uca; Ludwig, Christian

    2010-03-01

    The quantities of e-waste are expected to increase sharply in Chile. The purpose of this paper is to provide a quantitative data basis on generated e-waste quantities. A material flow analysis was carried out assessing the generation of e-waste from computer equipment (desktop and laptop PCs as well as CRT and LCD-monitors). Import and sales data were collected from the Chilean Customs database as well as from publications by the International Data Corporation. A survey was conducted to determine consumers' choices with respect to storage, re-use and disposal of computer equipment. The generation of e-waste was assessed in a baseline as well as upper and lower scenarios until 2020. The results for the baseline scenario show that about 10,000 and 20,000 tons of computer waste may be generated in the years 2010 and 2020, respectively. The cumulative e-waste generation will be four to five times higher in the upcoming decade (2010-2019) than during the current decade (2000-2009). By 2020, the shares of LCD-monitors and laptops will increase more rapidly replacing other e-waste including the CRT-monitors. The model also shows the principal flows of computer equipment from production and sale to recycling and disposal. The re-use of computer equipment plays an important role in Chile. An appropriate recycling scheme will have to be introduced to provide adequate solutions for the growing rate of e-waste generation.

  10. Oxygenation va