Detecção de mudanças ambientais na Antártica através de dados de sensoriamento remoto e mapas históricos

Abstract

Ice masses in the South Shetland Islands, Antarctica, are relatively thin and near or at the melting pressure point. They are, therefore, very sensitive t0 climatic variations. This work discusses glaciers retreat observed since 1950s in lhe Antarctic Specially Managed area(ASMA) of Admiralty Bay in King George Island. From 1956 to 1979 this area lost 4.3 km2(2%) of its ico cover. Further 4.9 km2 were lost in the period 1979-1988; 6.2 km2 from 1988 to 1995 and finally 7.1 km2 from 1995 to 2000. Totally 22.5 km2 disappeared (10% of the original ice cover. i.e. in 1956). The ice retreat magnitude in this period cannot be attributed co in-buill variulions of Ihe glacier system. Further, it is associated to similar glaciers retructions and ice shelves collapses in the northern most part of the Antarctic Peninsula. Probably this general ice retreat results from or is enhanced by the atmospheric warming recorded for the region since 1940s.