Glacial history of the NE Antarctic Peninsula region over centennial to millennial timescales

点击翻译按钮获取中文摘要

When glaciers and ice sheets melt, they release large volumes of fresh water into the oceans. The release of fresh water into the oceans not only raises sea level but also influences deep sea circulation and therefore regional climate. On the Antarctic continent, the largest freshwater store on the planet, glaciers are bufferered from the oceans by large ice shelves. These ice shelves form when glaciers reach sea level and spread out to form a floating or grounded shelf. Recent media coverage of Twentieth Century Antarctic ice shelf collapse has focused the world's attention on this topic and it has been suggested that many ice shelves, particularly around the Antarctic Peninsula, are now becoming unsable as a resut of global temperature rise. Against this background, it is important that we understand the behaviour of Antarctic glaciers and ice shelves in the past, present and future. The aim of this project is therefore to reconstruct the outline and evolution of the Antarctic Peninsula Ice Sheet through the Quaternary Period (the last two million years). We will do this using a variety of different methods including mapping of glaciers and associated landforms from satellite imagery and in the field; collecting samples of rock from glacial moraines for dating with cosmogenic isotope dating; and comparing our evidence on land to previous studies from offshore cores that record past fluctuations of the Antarctic Peninsula Ice Sheet. Obtaining dates for the timing of periods of growth and decay of the Antarctic Peninsula Ice Sheet will enable us to reconstruct the former fluctuations of this ice mass and therefore to make predictions about its possibe future behaviour. We will also be in a position to draw conclusions about whether or not the ice shelves surrounding the Antarctic Ice Sheet have collapsed in the past.