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Interpretação geomorfológica e evolução do ambiente de deglaciação da geleira Ecology, ilha Rei George, Antártica

2012; Volume: 5; Issue: 1 Linguagem: Inglês

10.31789/pab.v5n1.008

0103-4049

Kátia Kellem da Rosa, Rosemary Vieira, Francisco Ferrando Acuña, Jefferson Cárdia Simões,

Cryospheric studies and observations

This article presents of geomorphologic and sedimentologic interpretations of samples collected from Ecology Glacier proglacial area, King George Island, Antarctica.This study identifies different types of deposits found at the proglacial area of the glacier, thus building a geomorphologic map of this area and a model for the deglaciation evolution.Field and laboratory work analyzing sediments, photointerpretation of aerial photographs ( 2003) at the scale of 1:50,000, provided by the SHOA/SAF (Servicio Hidrográfico y Oceanográfico de la Armada de Chile), and analysis of SPOT satellite images taken in different years.The glacier has a wet basal thermal regime, based on the large proportion of fine sediments, striated rocks and clast pavements, stoss and lee features and other types of subglacial deposits.The model of evolution for deglaciation if the glacier shows that the retreating rate has increased in the last decades, and it has been more intense on the northern part of the proglacial area than on the south.Two main phases may be recognized from the images: I -1956-1979 (23 years) very low rate and II -1988II - -2005 (17 years (17 years) high rate of retreat or stagnation.Each retreat phase left sedimentary and erosional features, such as frontal moraines, subglacial deposits and striations observed on rock blocks: these indicate a predominant 27 • NE ice flow direction for the Ecology glacier.We believe it is possible to quantify the retreat by measuring distances between different positions of glacier margin.