The rockglaciers of the Cordillera del Tigre, Mendoza, Argentina.

MARIANO CASTRO; DARIO TROMBOTTO

Congreso; International Glaciological Coonference VICC 2010 "Ice and Climate Change": A View from the South; 2010

Abstract   An inventory of rockglaciers in the Cordillera del Tigre, located between 32° 11’ S and 32° 45’ S in the NW of the province of Mendoza, Argentina is presented. The surface of possible permafrost in this region is estimated to be of 1284 km2 approximately. The lower limit for permafrost is 3600 m ASL. Mesoforms have been mapped interpreting satellite images (Aster) and aerial photographs which revealed a remarkable concordance with this limit.   95 active rockglaciers with an average surface of 0.5 km2 and a minimum length of 200 m have been counted. The biggest rockglacier has a surface of 2.37 km2. Rockglaciers are generated as landforms derived from uncovered glaciers, glaciaretes or nearby perennial snow patches or they may also be created exclusively by cryogenic processes. A classification of the latter allows to affirm, that a cryogenic origin (73) is more frequent than that generated by uncovered glaciers or perennial snow patches (22).   Comparing the surfaces, rockglaciers turn out to be more important with 47.77 km2 than glaciated surfaces or perennial snow patches with 39.79 km2. This is a common phenomenon in the Dry Andes which explains the enormous importance of these landforms as water supplies.