Massive canyon found beneath Greenland ice
DOI: 10.1063/PT.5.027309
BBC : One of the largest canyons in the world, comparable in size to the US’s Grand Canyon, has been found to lie beneath the giant ice sheet covering most of Greenland. Researchers led by Jonathan Bamber of Bristol University accidentally discovered the canyon while researching the effects of global warming on Greenland ice. By studying ice-penetrating radar images collected by aircraft, the team has determined that the canyon was carved by a large river, not a glacier, more than 4 million years ago. They also found that because Greenland’s ice sheet is so heavy—being about 3 km thick—that it’s causing the island to sag in the middle. Should global warming completely melt it, sea levels could rise by as much as 7 m and several major cities could be flooded. The team’s results were published online today in Science.
