By Sid Perkins
Floods that occasionally surge from immense lakes trapped beneath the Antarctic ice sheet can significantly speed the flow of ice in overlying glaciers, a new study shows.
Scientists have known about the existence of large subglacial lakes in Antarctica — some of them larger than North America’s Lake Ontario — for decades. Only in the last few years, however, have satellite observations of shifts in the ice cap hinted that large volumes of water sometimes spill from one lake to another (SN: 6/17/06, p. 382).
Now, scientists’ observations, published online in Nature Geoscience on November 16, link one such flood to a 14-month–long acceleration of one of Antarctica’s largest glaciers.
The findings provide “the piece in the water-iceflow puzzle that had been missing so far: direct evidence for glacier acceleration as a result of subglacial floods,” says Helen Amanda Fricker, a glaciologist at Scripps Institution of Oceanography in La Jolla, Calif. “This paper really nails it.”