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Sea ice collapses in previously stable East Antarctica

DEVELOPMENT… The story will be updated as new information can be verified. Updated 3 times

An ice floe the size of New York has collapsed in East Antarctica, an area long thought to be stable and little affected by climate change, worried scientists said on Friday.

The collapse, captured by satellite images, marked the first time in human history that the frigid region has experienced a sea ice collapse. It came at the start of a monstrous heat spell last week, when temperatures soared more than 70 degrees (40 degrees Celsius) above normal in parts of East Antarctica. Satellite photos show the area has shrunk rapidly over the past two years, and now scientists are wondering if they have overestimated East Antarctica’s stability and resilience to global warming that has rapidly melted the ice on the small west side and the vulnerable peninsula.

The ice shelf, about 460 square miles wide (1,200 square kilometers) holding the Conger and Glenzer glaciers back from warmer water, collapsed between March 14 and 16, the ice specialist said. Catherine Walker ice cream from the Woods Hole Oceanographic Institute. She said scientists have never seen this happen in this part of the continent, which makes it worrying.

“The Glenzer Conger Ice Shelf was probably there for thousands of years and it will never be there again,” said University of Minnesota ice scientist Peter Neff.

The problem is not the amount of ice lost in this collapse, Neff and Walker said. It is negligible. It’s more about where it happened.

Neff said he was concerned that previous assumptions about the stability of East Antarctica were not correct. And that’s important because if the frozen water in East Antarctica melted – and it’s a process lasting many millennia if not more – it would raise seas around the world by more than 160 feet (50 meters). ). That’s more than five times the ice of the more vulnerable West Antarctic Ice Sheet, where scientists have focused much of their research.

Helen Amanda Fricker, co-director of the Scripps Polar Center at the University of California, San Diego, said researchers need to spend more time examining this part of the continent.

“East Antarctica is starting to change. There is mass loss starting to happen,” Fricker said. “We need to know how stable each of the ice shelves are, because once that one disappears”, it means that the glaciers are melting in the warming water and “some of this water will come to San Diego and elsewhere”.

Scientists had seen this particular ice shelf – the closest to Australia – shrink quite a bit since the 1970s, Neff said. Then in 2020, shelf ice loss accelerated to lose about half of itself every month or so, Walker said.

“We’re probably seeing the result of long-standing increased ocean warming there,” Walker said. “it just melted and melted.”

Yet one expert thinks only part of East Antarctica is of concern.

“Most of East Antarctica is relatively safe, relatively invulnerable and some areas are vulnerable to it,” said British Antarctic Survey geophysicist Rob Larter. “The overall effect of climate change around East Antarctica is that it’s chipping away at the edges of the ice sheets in some places, but it’s actually adding more snow in the middle.”

Last week, what is called an atmospheric river dumped a lot of warm air – and even rain instead of snow – on parts of East Antarctica, getting temperatures so much above normal that scientists have spent the last week discussing it. The nearest station to the collapsed ice shelf is Australia’s Casey Station, about 300 kilometers away and it reached 42 degrees (5.6 degrees Celsius), about 18 degrees (10 degrees Celsius) higher than the normal.

And that, says Walker, “is probably something like, you know, the last straw on the camel’s back.”

Fricker, who has explored another, more stable ice shelf in East Antarctica, said an ice shelf there “is the calmest, most serene place you can imagine” .

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