IANIGLA   20881
Unidad Ejecutora - UE
congresos y reuniones científicas
Glacier Fluctuations in the Dry Andes (29º20'S) of Argentina, between 1960 and 2005
Santiago / Chile
Conferencia; 4th Alexander von Humboltdt International Conference. The Andes: Challenge for Geosciences; 2008
Institución organizadora:
Facultad de Ciencias Físicas y Matemáticas. Universidad de Chile (fcfm)
The rivers in the Andes of Argentina (29º-36ºS) are fed by snow-ice melt from the high mountain catchments, so the water is critical for adjacent semiarid lowland communities and human activities. There are few studies about glacier fluctuations at these latitudes in the Andes Cordillera, so this work fills a gap concerning the behaviour of glaciers in response to climate. The goal of this study is to present the area glacier fluctuations of the Los Amarillos, Guanaco, and Canito glaciers located at 29º20´S latitude in the Dry Andes of Argentina, based on aerial photos, Landsat TM images, a IKONOS image of 2005, and fieldwork, during the period 1959-2005. The altitudes range from west to east between 5300-5100 and 3800 m asl. The Los Amarillos, Guanaco, and Canito glaciers are medium-size (1.7, 1.2 and 1.4 km long, respectively). The Los Amarillos glacier presents a slope ranging from 15º to 25º, and a south-east orientation. The Guanaco glacier is relatively flat with a slope ranging from 5° to 25°, and the Canito glacier is a valley glacier with a slope of 5º-15º in the upper part and 15º-25º in its front; both glaciers present an east orientation. The glaciers in the study area behave as "reservoir glaciers" with slow movement. They roughly present a similar behavior from 1959 to 2005. The Los Amarillos glacier present the same area in 2005 as it did in 1959, but within this whole period of time the area of this glacier experienced variations. The Guanaco glacier lost 4% of its area, while the Canito glacier lost significant amounts of area (33%) during this period of time. The Los Amarillos and Guanaco glaciers increased their areas between 1959 and 1986, while the Canito glacier retreated during 1959-1981. These three glaciers showed a maximum increase in 1981-1986. This increase was followed by an important decrease of the areas during 1986-1997, a minor increase in 1997-2000 and a moderate retreat in 2000-2005. El Niño warm events at these latitudes are generally associated with high snow precipitation. The increase of glacier areas in 1981-1986 and 1997-2000, may be the consequence of the strong warm El Niño events of 1982/1983, 1986/1987 and 1997/1998. We present the relation between the long record precipitation time series at the El Indio and Santiago-Pudahuel meteorological stations in Chile, and the glacier fluctuations in the Dry Andes. Keywords: glacier fluctuations; climate change; Holocene; present glaciers; Dry Andes; Argentina