Mystery of Greenland's Disappearing Lakes

Scientists are baffled after two lakes drain, leaving behind craters.

ByABC News
January 22, 2015, 2:16 PM
Researchers at The Ohio State University were creating the highest-resolution maps of the Greenland Ice Sheet made to date, when they discovered a crater, shown here, which had once been the site of a sub-glacial lake.
Researchers at The Ohio State University were creating the highest-resolution maps of the Greenland Ice Sheet made to date, when they discovered a crater, shown here, which had once been the site of a sub-glacial lake.
Ian Howat, Ohio State University. WorldView Imagery Copyright DigitalGlobe Inc.

— -- Scientists are baffled after two lakes in Greenland were mysteriously drained of billions of gallons of water.

One lake was so large that a mile-wide crater was left behind after it was drained in the span of a few weeks. Another sub-glacial lake has been filled and emptied twice in the last two years.

The findings were published separately for each lake in the journals "Nature" and "The Cryosphere."

Ian Howat, a professor at Ohio State University, who studied the lake that left behind a mile-wide crater, said the findings of the study were "catastrophic."

PHOTO: A map of a portion of southwest Greenland is pictured.
A map of a portion of southwest Greenland is pictured.

"The draining of the lake may be showing us that the plumbing system under the ice is changing because more water is melting from the surface and flowing into it," Howat told ABC News.

The second lake was discovered by a team from Cornell University. When mapping Greenland's ice sheet, the team learned that when the lake is drained and filled again, it creates stored heat that can change the composition of the ice.

PHOTO: In April 2014, researchers flew over a site in southwest Greenland to find that a sub-glacial lake had drained away. This photo shows the crater left behind, as well as a deep crack in the ice.
In April 2014, researchers flew over a site in southwest Greenland to find that a sub-glacial lake had drained away. This photo shows the crater left behind, as well as a deep crack in the ice.

The problem is further exacerbated by overflowing meltwater hindering the ice sheet's drainage system. This creates what researchers call "blowouts," leading to drainage.

Howat said it's possible there are more sub-glacial lakes in Greenland that have yet to be discovered.

"First, we now know that these lakes can exist, but we don't know how many lakes there are or how much water is in them," he said. "If there's a lot, then draining of lakes could be another way that melt of the ice sheet contributes to [a rise in] sea level."