Dry Andes


The Dry Andes is a climatic and glaciological subregion of the Andes. Together with the Wet Andes it is one of the two subregions of the Argentine and Chilean Andes. The Dry Andes runs from the Atacama Desert in northern Chile and Northwest Argentina south to a latitude of 35°S in Chile. In Argentina the Dry Andes reaches 40°S due to the leeward effect of the Andes. According to Luis Lliboutry
the Dry Andes can be defined by the distribution of penitentes. The southernmost well developed penitentes are found on Lanín Volcano.
The Principal Cordillera near Santiago may have subject of significant glaciation as early as 1 million years ago as indicated by the development of glacial valleys.

Paleogeography, paleoclimatology and paleoglaciology

Though precipitation increases with the height, there are semiarid conditions in the nearly towering mountains of the Andes. This dry steppe climate is considered to be of the subtropic type at 32-34° S. In the valley bottoms only dwarf scrubs grow. The largest glaciers, e.g. the Plomo glacier and the Horcones glacier, do not reach in length the ice thickness is not very significant. During glacial times however, c. 20,000 years ago, the glaciers were over ten times longer. On the east-side of this section of the Mendoza Andes they flowed down to and on the west-side to c.. The massifs of Cerro Aconcagua, Cerro Tupungato and Nevado Juncal are situated deca-kilometres away from each other and were connected by a joint ice stream network. Its dendritic glacier arms, i.e. components of valley glaciers, were up to long, over thick and spanned a vertical distance of. The climatic glacier snowline was lowered from the current to during glacial times.