![]() ![]() As meltwater at the bottom refreezes over hundreds to thousands of years, the researchers believe it radiates heat into the surrounding ice sheet, making it pick up its pace as the ice becomes softer and flows more easily. The structures cover about a tenth of northern Greenland, the researchers estimate, becoming bigger and more common as the ice sheet narrows into ice streams, or glaciers, headed for the sea. "We think the refreezing process uplifts, distorts and warms the ice above, making it softer and easier to flow." "We see more of these features where the ice sheet starts to go fast," said the study's lead author, Robin Bell, a geophysicist at Columbia University's Lamont-Doherty Earth Observatory. ![]() The results are published in the latest issue of Nature Geoscience. The newly revealed forms may help scientists understand more about how ice sheets behave and how they will respond to a warming climate. Using ice-penetrating radar, researchers have discovered ragged blocks of ice as tall as city skyscrapers and as wide as the island of Manhattan at the very bottom of the ice sheet, apparently formed as water beneath the ice refreezes and warps the surrounding ice upwards. view moreīeneath the barren whiteness of Greenland, a mysterious world has popped into view. Image: Melting and refreezing at the bottom of ice sheets warps the layer-cake structure above, as seen in this radar image from Greenland. ![]()
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