Image

Water on Ice

May 2, 2012

During a 2008 expedition, glaciologists Sarah Das (WHOI), right, and Ian Joughin (University of Washington) trek toward a lake that formed as ice melts in summer and pools in depressions atop the Greenland ice sheet. The researchers confirmed that supraglacial lakes like these can build up enough pressure to crack at their bottoms, sending torrents of water to the base of the glaciers. The water greases the skids between ice and ground, speeding up the glaciers’ flow toward the ocean. Climate change is accelerating this process, releasing more ice into the ocean, where it melts and raises sea levels.(Photo by Chris Linder, Woods Hole Oceanographic Institution)