Glacier retreat in Patagonia

Abstract

The Southern Patagonian Ice Field, with 12,500 km2 of ice and snow, has suffered a marked retreat of its glaciers that has increased in the last 35 years. The area of this ice cap in Argentine territory covers 3,500 km2 where thirteen large glaciers descend to the basins of Viedma and Argentino Lakes, both united to the great mass of continental ice. They have been watched monthly since 1986 by the eyes of the best spotters: Earth Observation Satellites. Since then and mostly in last years, we can observe an increasing velocity with a positive trend and a large volumetric retreat throughout the area, exposing new water bodies and thus modifying the flow of the rivers and lakes. Upsala glacier was considered the longest in Patagonia Argentina, but today it has receded so much that it is separating from its tributaries, such as the Bertacchiglacier. We can observe and measure its retreat by means of Landsat, SPOT and Sentinel satellites time series, among others. The famous Perito Moreno glacier used to form an ice bridge that fell every three or four years. However, it is now on an annual basis. Viedma glacier, the largest in the country, can no longer be visited by boat due to its larger ice breaks that endanger the lake tours: icebergs are so huge that satellites can see them from space.