A new surge event of Grande del Nevado glacier, Mendoza

LIDIA FERRI HIDALGO; LYDIA ESPIZUA

Valdivia

Conferencia; Internacional Glaciological Conference. 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 severalkilometers in a sudden, brief and quick way. Glacier Grande delNevado is a surging glacier located in the Argentinean side of theAndes, east of the international boundary with Chile (33°06?S,70°03?W).The advances of this glacier have been documented fromthe beginning of the 20th century on the basis of historical documents,aerial photographs, satellite images and fieldwork. In 1934 acatastrophic flood was caused by a sudden discharge of a proglaciallake. That lake was formed by the rapid advance of the Grandedel Nevado glacier, which flows transversal to the valley and producesriver damming. In 1984 the glacier advanced again, but in thiscase the ice-dammed lake drained through a subglacial tunnel. Anew surge took place between the end of 2006 and the beginning of2007, but the main advance occurred during the winter of 2007. Theglacier moved forward a total of 3.5 km, with a maximum measuredvelocity of 34 m d-1. This new surge was studied with Landsat 5 TMand Aster images. Recent field observations made on September2009 showed that the glacier tongue remains in the same positionand the presence of a subglacial tunnel which continuously drainsthe river prevents the formation of a lake. Climate and weather couldaffect surge initiation, termination and magnitude. Due to this fact,a temperature series of a nearby meteorological station is beinganalysed to study the probable evolution of this new glacier surge.