Antarctic ice sheet

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A satellite composite image of Antarctica

The Antarctic ice sheet covers about 98% of the Antarctic continent and is the largest single mass of ice on Earth. The ice sheet covers an area of almost 14 million square km and contains 30 million cubic km of ice. Around 90% of the fresh water on the Earth's surface is held in the ice sheet, an amount equivalent to 70 m of water in the world's oceans. In East Antarctica, the ice sheet rests on a major land mass, but in West Antarctica the bed can extend to more than 2,500 m below sea level. The land would be seabed if the ice sheet were not there.^[1]

Ice enters the sheet through snow and frost and leaves by calving of icebergs and melting, usually at the base but also sometimes at the surface at warm sites^[2].

Recent satellite data reported by NASA shows evidence that the total amount of ice in Antarctica has decreased in the past few decades. This is significant because there is a large amount of ice in the area and some climate models predicting global warming also predict that some of the most severe warming would occur in Antarctica. This melting ice would raise sea levels significantly ^[3]. On the other hand, a warming climate in the southern hemisphere would transport more moisture to Antarctica so the ice sheet would in fact grow and somewhat counteract rising sea levels.^[4]