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

• Published in: Pesquisas em Geociências
• Main Authors: ARIGONY NETO, Jorge, MENDES JÚNIOR, Cláudio W., RIBEIRO, Rafael R., SIMÕES, Jefferson C.
• Format: Article in Journal/Newspaper
• Language: Portuguese
• Published: Instituto de Geociências /Universidade Federal do Rio Grande do Sul 2009
• Subjects: fácies de geleiras; Península Antártica; ERS SAR; Geociências; glacier facies; Antarctic Peninsula; Antarctic; Austral; Corry; Eagle Island; Nordeste; Ross Island; The Antarctic; Trinity Peninsula; Vega Island; Antarc*; antartic*; Antártica; James Ross Island
• Online Access: https://seer.ufrgs.br/index.php/PesquisasemGeociencias/article/view/17867

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. Imagens ERS SAR adquiridas no verão austral de 1993 e 1996-97 e primavera de 1996 e 2000 foram usadas para a análise das variações espaço-temporais de fácies ou zonassuperficiais de neve e gelo de geleiras (ZSNG, i.e., zonas de neve seca, percolação, neve úmida e gelo exposto) da região nordeste da Península Antártica (PA). A área de estudo compreende as ilhas James Ross, Vega, Eagle e Corry e a região norte da Península Trinity. Algoritmos baseadosem regras de decisão foram desenvolvidos para discriminar as ZSNG nas imagens ERS SAR. Dados da cobertura de rochas e da linha de costa do Antarctic Digital Database ...