Strange Crater Appears in East Antarctica
When it comes to climate change, Antarctica is fast becoming the penguin in the frigid coal mine. Just days after news spread about the quickly-expanding crevice in the Larsen Ice Shelf on the continent’s western peninsula, researchers studying the King Baudouin Ice Shelf in East Antarctica found a strange crater that may indicate things are not exactly solid underneath it either.
At the time, the media reported that it was probably a meteorite impact crater. My response was: in that area?
According to the report he co-authored in Nature Climate Change, Jan Lenaerts of Utrecht University in the Netherlands led a team of researchers from the Netherlands, Belgium and German to study a strange crater – 2 km (1.2 mi) wide – on the King Baudouin Ice Shelf, located south of the tip of Africa.
Climate models, satellite data and an onsite expedition in January 2016 to peer into the abyss proved Lenaerts’ hunch – the hole was not an impact crater. They found that it was an opening caused by the ice shelf collapsing over a hidden lake. The probable cause was a combination of strong winds blowing away the top layer of reflective white snow which exposed the lower, darker, heat-absorbing layer to solar rays, melting the ice underneath it.
That’s bad news, but it gets worse. The crater lake was not alone – 55 meltwater lakes were detected, with some measuring kilometers in diameter. These lakes occur in warmer West Antarctica but have been extremely rare in the frigid east … until now.
And then it gets really bad. The water from the crater lake was not staying under the crater or the shelf but flowing out to the ocean through a moulin – a vertical hole in the ice. That stunned researcher and study co-author Stef Lhermitte.
That was a huge surprise. Moulins typically are observed on Greenland. And we definitely never see them on an ice shelf.
Well, there’s one now and probably more. While most of the world’s scientific attention has been on the instability of West Antarctica melting ice shelves and their contribution to the rise in global sea levels, the warm water pouring out of the Moulin on the other side may change things, says Lenaerts:
But our research now suggests that the much larger East Antarctica ice sheet is also very vulnerable.
You know things are bad when scientists wish they could blame a mysterious Antarctic crater on a meteor instead of the real cause.