Incredible Time-Lapse Video Shows Giant Greenland Lake Disappearing Within Hours

[Judi Lynn]

By Stephanie Pappas - Live Science Contributor 5 hours ago

The Greenland Ice Sheet may be even more unstable than scientists previously thought, according to new research that reveals how lakes on the surface of Greenland's glaciers drain toward the bottom of the ice sheet within hours.

An impressive new time-lapse video shows one of these vanishing acts on Store Glacier in western Greenland. In July 2018, the lake lost two-thirds of its volume in a mere 5 hours, gushing out the equivalent of 2,000 Olympic-size swimming pools. Even after the lake finished draining, the fracture that emptied it remained, leaving an easy conduit from the surface of the glacier to its base just over a half-mile (1 kilometer) below.

"Every year, there are many hundreds of large waterfalls providing water, but also large quantities of energy, down to the base of the ice sheet," said Poul Christoffersen, a glaciologist at the University of Cambridge's Scott Polar Research Institute. This water lubricates the bottom of the ice sheet, hastening its movement toward the sea, where it can contribute to sea level rise.

Since satellite observation of the island began in the 1970s, the number of meltwater lakes dotting Greenland's ice has risen. These seasonal lakes have also started growing larger, and appearing at higher elevations, than in the past. These trends are linked with a general warming trend in Greenland, which has been experiencing high rates of melt as the globe warms.

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https://www.livescience.com/greenland-ice-sheet-lake-drains.html