A valley the size of the Grand Canyon a mile beneath the ice in West Antarctica, may be contributing to ice loss in the region, the British scientists who discovered it say.
Researchers have been monitoring large ice sheets in Greenland and Antarctica for decades to see how and whether they affect climate change.
Thinning ice in west Antarctica accounts for nearly 10 per cent of global sea level rise as rising global average temperatures cause glaciers and ice caps to melt, threatening coastlines from Vietnam to Florida and forcing low-lying cities to build costly flood defences.
Scientists at the University of Aberdeen and the British Antarctic Survey have discovered a sub-glacial valley under the Ferrigno Ice Stream, a region that has only been visited once before, in 1961.
The rift valley, created millions of years ago and subsequently covered by ice, is connected to the warming ocean, and helps to show how climate change is affecting the ice sheet, they said in a paper published in the journal Nature yesterday.