Paleogeography, Paleoclimatology and Paleoglaciology
Though precipitation increases with the height, there are semiarid conditions in the nearly 7000 m towering highest mountains of the Andes. This dry steppe climate is considered to be typically of the subtropic position at 32-34° S. Therefore in the valley bottoms do not grow woods but only dwarf scrub. The largest glaciers, as e.g. the Plomo glacier and the Horcones glaciers do not even reach 10 km in length and have an only insignificant ice thickness. At glacial times however, c. 20 000 years ago, the glaciers were over ten times longer. On the East-side of this section of the Mendozina Andes they flowed down to 2060 m and on the West-side to c. 1220 m asl. The massifs of Cerro Aconcagua (6962 m), Cerro Tupungato (6550 m) and Nevado Juncal (6110 m) 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 112.5 km long, over 1020, i.e. 1250 m thick and overspanned a vertical distance of 5150 altitude metres. The climatic glacier snowline (ELA) was lowered from currently 4600 m to 3200 m at glacial times.
Read more about this topic: Dry Andes