CAPTURA. Repositorio Academico de la Universidad de Chile
(5.176 recursos)
Captura almacena y conserva la producción de conocimiento generado por docentes e investigadores de la Universidad de Chile, y la hace visible desde los portales académicos internacionales.
Mostrando recursos 1 - 20 de 49
1.
Geomorphological evidence for variations of the North Patagonian Icefield during the Holocene - Glasser, Neil; Jansson, Krister; Harrison, Stephan; Rivera, Andrés
Elucidating the timing and extent of former glacier fluctuations is important because of the palaeoclimatic inferences that can be drawn from such studies. Here we present new geomorphological evidence of the patterns of glacier behaviour around the North Patagonian Icefield during the Holocene. Mapping is based on visual interpretation of Landsat 7 ETM+ and Terra ASTER satellite images, including the contemporary glaciers, areas of ice-scoured bedrock, trimlines, glacial lineations, terminal moraines, sandur and fluvial sediments, deltas and ice-contact deposits and alluvial fans. Recession of the icefield is marked by three distinct moraine sets. These moraine sets are interpreted as marking...
2.
Ice-elevation changes of Glaciar Chico, southern Patagonia, using ASTER DEMs, aerial photographs and GPS data - Rivera, Andrés; Casassa, Gino; Bamber, Jonathan; Kääb, Andreas
Hielo Patagonico Sur (HPS; southern Patagonia icefield) is the largest temperate ice mass at mid-latitudes in the Southern Hemisphere. With few exceptions, the glaciers in this region have been retreating during the last 50 years. Based on field data, vertical aerial photographs and satellite images, ice-elevation changes since 1975 on Glaciar Chico, one of the main tongues of HPS, are presented. A maximum ice thinning of 5.4 +/- 0.55 m a(-1) was observed at the glacier front between 1975 and 1997. Global positioning system (GPS) data were used in the accumulation area of the glacier to infer a thinning rate...
3.
Elevation change and ice flow at Horseshoe Valley, Patriot Hills, West Antarctica - Casassa, Gino; Rivera, Andrés; Acuña, César; Brecher, Henry; Lange, Heiner
Patriot Hills is located at 80 degrees 18'S, 81 degrees 22'W, at the southernmost end of the Heritage Range, Ellsworth Mountains, West Antarctica. A comparison of glacier elevation data and ice velocities obtained by the differential global positioning system in the period 1996-97 is presented. Ablation/ accumulation rates measured at a network of stakes in Horseshoe Valley show average accumulation of 70 kg m(-2) a(-1) in the central part of the valley, and a maximum ablation of -170 kg m(-2) a(-1) at the edge of the blue-ice area, close to Patriot Hills. Changes in the surface elevation of the glacier...
4.
Glacier shrinkage and negative mass balance in the Chilean Lake District (40 degrees S) - Rivera, Andrés; Brown, Francisca; Casassa, Gino; Acuña, César; Clavero, Jorge
Ice-capped volcanoes of the Chilean Lake District have shown significant glacier retreat during recent decades, probably in response to tropospheric warming and precipitation decrease. Volcan Mocho-Choshuenco (39 degrees 55'S, 72 degrees 02'W) is one of the main active volcanoes in this part of the country. A mass balance programme was initiated on its southeastern glacier in 2003, in view of its representative conditions as an ice body that is presumably not affected by current volcanic activity. The glaciers of this volcano have been retreating and shrinking in recent decades; by 2003 there 2 had been a reduction of 40% of...
5.
Glacier wastage on southern Adelaide Island, Antarctica, and its impact on snow runway operations - Rivera, Andrés; Casassa, Gino; Thomas, R.; Rignot, E.; Zamora, R.; Antúnez, D.; Acuña, César; Ordenes, F.
The variations and dynamics of the southern edge of Fuchs Ice Piedmont, Adelaide island (67 degrees 45'09'S, 68 degrees 55'04'W), Antarctic Peninsula, are presented. The snow-covered surface of the glacier has been used since the 1960s for landing aeroplanes in support of British, and more recently Chilean, operations at nearby Teniente Carvajal station (formerly known as Adelaide T). In recent years, snow conditions in the runway area have progressively deteriorated, due to increasingly early summer melting. Radio-echo sounding, global positioning system and remotely sensed data have been analyzed for mapping the crevasse and ice velocity fields, as well as the...
9.
Contradicciones socio-territoriales y anclaje (embeddedness) de las actividades turísticas rurales: ejemplos de la vitivinicultura y las actividades forestales en Chile. - Romero Aravena, Hugo; Toledo, Ximena; Romero Toledo, Hugo
El concepto de anclaje (embeddedness) o relación critica entre las actividades globales, como el turismo, y las realidades socio-espaciales locales, como las comunidades rurales, puede ser analizado a través de un complejo dinámico, conformado por tres conceptos claves (capital-actores-conocimiento), sus modelos correspondientes (inversiones-campos sociales y análisis de discursos), y sus efectos sobre el desarrollo regional, la pobreza y el poder.
11.
Santiago de Chile: antecedentes demográficos, expansión urbana y conflictos - Ferrando Acuña, Francisco
Cuando la expansión de Santiago se efectuó sobre los sectores rurales circundantes y también, en los últimos decenios, en polígonos altos en busca de mejores condiciones ambientales y de calidad de vida, también impensadamente, se efectuó hacia áreas de mayor riesgo. La ciudad ha cuadruplicado su superficie en los últimos 50 años y se acerca al límite de su capacidad de carga, presionado por la ocupación de áreas morfodinámicamente inestables. Son, por lo tanto, motivo de especial preocupación los desastres asociados en parte a procesos naturales, a los que están expuestas ciudades como Santiago, con una expansión asociada a un...
12.
Agricultura Urbana: Nuevas Estrategias de Integración Social y Recuperación Ambiental en la Ciudad. - Moreno Flores, Osvaldo
La Agricultura Urbana surge como potencial plataforma de desarrollo local y comunitario, asumiendo el desafío de estructurar sinergias y complementariedad entre la recuperación de los recursos del hábitat y la creación de actividades productivas agro-culturales, generando un encadenamiento operativo de la dimensión ecológica, económica y social del concepto de sustentabilidad. A través del Paisaje, como disciplina analítica y proyectual del territorio, es hora de explorar nuevas formas de hacer ciudad, para generar desde las potencialidades, intereses y aspiraciones de la comunidad local un efectivo entrelazamiento entre la recuperación físico-ambiental del espacio urbano y periurbano, y la inclusión al ámbito ciudadano...
13.
Emerging urbanization in the Southern Andes - Romero Aravena, Hugo; Ordenes, Fernando
Environmental degradation caused by
urbanization of the Andean piedmonts and
related pre-mountain systems can be
observed along both Chilean and Argentinean
slopes, with a consequent decrease
in vegetation productivity, biomass and soil
moisture, and generation of heat islands.
This leads to degradation of Andean environmental services such as water infiltration and flood control. Fragmentation of vegetation patches and corridors are among the other main impacts on the natural environment. These land cover and land use changes have in turn increased the frequency and magnitude of natural hazards, and the concentration of air, water and soil pollution. Unfortunately, this makes large Latin American cities examples of unsustainable development.
Urban...
14.
"Urban versus rural" no longer matches reality: an early public agro-residential development in periurban Santiago, Chile - Madaleno, Isabel María; Gurovich, Alberto
The paper discusses the validity of the "urban versus rural" dichotomy in scientific literature, statistics and urban planning practice, especially in empirical studies developed around the issue of vegetable and animal farming inside and around cities. Santiago's rural-urban interface is presented as a case study. Sample results extracted in early 2003 have shown that farming mixed with other land uses is even now a reality in Southern Santiago, supported in solidarity alliances and a characteristic life philosophy, giving researchers the possibility of exploring a living ecocity laboratory.
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