Scientists studying glaciers in Greenland have found that lakes of water on the surface of a glacier can quickly and completely cut all the way through to the base of the ice.
"If there is a crack or defect in the surface that is large enough, and a sufficient reservoir of water to keep that crack filled, it can create a conduit all the way down to the bed of the ice sheet," said Sarah Das, one of the scientists on the project.
Writing in the journal Science, the researchers describe a lake of meltwater covering 2.2 square miles containing 11 billion gallons of water draining completely within 24 hours — a flow rate exceeding that of Niagara Falls. The water from that lake appears to have cut completely through over 3,200 feet of ice to the base of the glacier. The researchers are working to understand how events like this one affect the ice itself and its movements.
Ian Joughin of the University of Washington and Sarah Das of the Woods Hole Oceanographic Institution discuss the team's findings — and what it's like to conduct research on the ice.