A new surge event of Grande del Nevado glacier, Mendoza, Argentina

FERRI HIDALGO, L.; ESPIZUA, L. E.

Valdivia, Chile

Conferencia; Ice and Climate Change: A view from the south; 2010

CECS

Surging glaciers are characteristic of the Central Andes of Argentina. During their active phases, glacier tongues advance several kilometers in a sudden, brief and quick way. Glacier Grande del Nevado is a surging glacier located in the Argentinean side of the Andes, east of the international boundary with Chile (33°06´S, 70º03´W).The advances of this glacier have been documented from the beginning of the 20th century on the basis of historical documents, aerial photographs, satellite images and fieldwork. In 1934 a catastrophic flood was caused by a sudden discharge of a proglacial lake. That lake was formed by the rapid advance of the Grande del Nevado glacier, which flows transversal to the valley and produces river damming. In 1984 the glacier advanced again, but in this case the ice-dammed lake drained through a subglacial tunnel. A new surge took place between the end of 2006 and the beginning of 2007, but the main advance occurred during the winter of 2007. The glacier moved forward a total of 3.5 km, with a maximum measured velocity of 34 m/d. This new surge was studied with Landsat 5 TM and Aster images. Recent field observations made on September 2009 showed that the glacier tongue remains in the same position and the presence of a subglacial tunnel which continuously drains the river prevents the formation of a lake. Climate and weather could affect surge initiation, termination and magnitude. Due to this fact, a temperature series of a nearby meteorological station is being analysed to study the probable evolution of this new glacier surge.