The ice is more than 3km thick in places, and contains more than half of Earth's fresh water. It constantly flows off the continent into the sea under the force of its own weight. By mapping the underlying topography of the bedrock beneath, the way that the ice flows can be understood. Ultimately this may help predict how Antarctic ice melt could affect global sea level rise in a warming world. It suggests that if all of Antarctica's ice melted, global sea level would rise by 58 metres.
The recently-published sub-ice topographic map builds on millions of records, including seven years of surface elevation measurements from NASA's ICESat satellite, and laser and ice penetrating radar measurements of ice thickness from airborne instruments. The terrain beneath the ice sheet has been mapped to the best resolution yet. It has revealed that the bedrock beneath Byrd Glacier in Victoria land is 2,870 metres below sea level, making it by far the lowest point on any of Earth's continental plates.
Image: The topography of Antarctica, beneath all the ice, as measured by the Bedmap Consortium. Photo: NASA Goddard Space Flight Center
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