Climate Change and recent variations in small Andean glaciers.

LEIVA, JUAN CARLOS; CABRERA, GABRIEL A.; LENZANO, MARÍA GABRIELA; BOTTERO, RAFAEL

Valdivia

Conferencia; International Glaciological Conference VICC 2010–Ice and Climate Change: A view from the South.; 2010

Small glaciers in the Andes of Mendoza and San Juan provinces show the impacts of global change. In spite of their small size their contribution to the water discharge of the rivers and streams of the region is very important during drought periods, when the annual snowfall in the central Andes is scarce. Previous studies in the central Andes of Argentina and Chile have shown that during drought periods the glacier contribution can reach up to 60 to 70 % of the total runoff. In this work we show the recent evolution of a number of small glaciers situated in the Andes between 29°S and 33°S. Field observations of seven small glaciers are included: Los Amarillos Glacier and its neighbour Amarillo Glacier, the Brown Glaciers, called Superior, Inferior and Norte, the Agua Negra Glacier and the Piloto Este Glacier. Studies at the larger Las Vacas Glacier are also included. The glaciological work conducted on each of these glaciers focussed on different aspects and spans different time intervals between 1965 and 2009. At Las Vacas Glacier (approximately 18.4 km2), digital terrain models (DEM) from Aster stereoscopic images, level 1 A, are used for assessing volume changes in the period 2001-2007. The applied methodology gives results where the error propagations can hardly be assessed.