USING ERS SAR IMAGES FOR THE MONITORING OF GLACIER FACIES ON THE NORTHEASTERN ANTARTIC PENINSULA

Abstract

ERS SAR images acquired in the austral 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 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 the GF discrimination in ERS SAR images. Rock and coastline data from the Antarctic Digital Database were used to mask outcropping rocks and sea water, respectively. Total areas and maximum values of GF altitudes were calculated and images of variations and frequency of 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. Significant changes were observed in GF on 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 different glaciers to the climatic, oceanographic and topographic parameters. The highest variations in GF were detected on the east side of the Trinity Peninsula, northwestern region of James Ross Island, eastern tip of Vega Island and western part of Eagle Island.