Science & Technology
Strange 'crater' discovered in Antarctica
December 13, 2016 | 65 comments
The ice sheets are showing worrying signs of collapse. Image Credit: CC BY 2.0 Jason Auch
A large hole in the King Baudoin ice shelf has challenged what we know of the East Antarctic ice sheet.
The mysterious 'crater', which had been initially reported to be a meteorite impact site, turned out to be a collapsed lake with a 'moulin' - a hole which allowed the water to flow into the ocean.
"That was a huge surprise," said study co-author Stef Lhermitte. "Moulins typically are observed on Greenland and we definitely never see them on an ice shelf."
Further investigation also revealed other meltwater lakes under the ice across the region which had up until now been considered far more stable than the West Antarctic ice sheet.
The explanation lies firmly in the way climate change has been affecting the planet's poles. In this case, the reflective snow on the surface had been blown away by warm winds, exposing the ice underneath which then absorbed the Sun's rays rather than bouncing them back in to space.
"Our research has shown that East Antarctica is also vulnerable to climate change," said study lead author Jan Lenaerts of Utrecht University in the Netherlands.
Under normal circumstances much of the ice erosion is compensated for by the accumulation of fresh snow and ice on the surface, but more recently scientists have determined that excess heat from global warming has been absorbed by the oceans, raising the average global air temperature.
"These processes - previously unseen in East Antarctica - indicate that further warming may amplify the risk of ice shelf collapse," said Martin Siegert of Imperial College London.
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