Estudo das variações espaço-temporais de fácies de geleiras da região nordeste da península Antártica (1993-2000) através de imagens ERS AMI SAR

Abstract

ERS AMI SAR images acquired in the summer 1993 and 1996-97 and spring 1996 and 2000 were used for analyses of spatio-temporal variations of glacier facies (GF, i.e., dry-snow zone, percolation zone, wet-snow zone and glacier ice) on the northeastern region of the Antarctic Peninsula (AP). The study area includes James Ross, Vega, Eagle and Corry islands and the northern region of the Trinity Peninsula. Algorithms based on decision rules were developed to discrimination of the GF in ERS AMI SAR images. Total areas and maximum values of altitude of the GF were calculated and images of variation and frequency in these zones were generated by using GIS spatial analysis tools. Furthermore, the GF dynamics were compared with mean daily surface air temperatures measured by meteorological stations. Significative changes were observed on the GF in the AP from 1993 to 2000. The GF dynamics showed good correlations with interannual and sazonal variations of the surface air temperatures. The spatio-temporal variations were interpreted as responses of the diferent glaciers to the climatic, oceanographic and topographic parameters. The highest variations in GF were detected on the east side of Trinity Peninsula, northwestern region of James Ross island, eastern tip of Vega island and western part of Eagle island.