For the first time, researchers have discovered lakes underneath the Greenland Ice Sheet. The two newly identified subglacial lakes each measure about 8 to 10 square kilometers, and are nearly 2,625 feet below the surface, according to Science World Report. They were likely much bigger—three times bigger—in the past, and as they likely control ice sheet flow, they also have an effect on global sea level changes. Scientists should be able to use them to study how ice could be affected by climate change.
Researchers at the University of Cambridge used airborne radar measurement to locate the lakes, which one calls "an important part of the ice sheet's plumbing system." There are almost 400 known lakes beneath the Antarctic ice sheets, but these are different, Xinhua reports. Specifically, they form differently—they're likely fed by melting water from the surface, unlike in Antarctica, where the surface is always freezing—and are connected to the surface, unlike the typically isolated Antarctic lakes.