The ice shelf fall, which was seen on satellite photographs, was the first in human history in the freezing location. It happened at the start of a bizarre warm period last week, when temperatures in certain parts of East Antarctica climbed to more than 70 degrees (40 degrees Celsius) above normal. Satellite images show the area has been diminishing significantly in recent years, and experts are now wondering if they underestimated East Antarctica’s durability and resistance to global warming, which has been rapidly melting ice on the smaller western continent.
The ice shelf, about 460 square miles wide (1200 square kilometers) holding in the Conger and Glenzer glaciers from the warmer water, collapsed between March 14 and 16, said ice scientist Catherine Walker of the Woods Hole Oceanographic Institute. She said scientists have never seen this happen in this part of the continent, making it worrisome.
“The Glenzer Conger ice shelf presumably had been there for thousands of years and it’s not ever going to be there again,” said University of Minnesota ice scientist Peter Neff.
The issue isn’t the amount of ice lost in this collapse, Neff and Walker said. That is negligible. It’s more about the where it happened.
Neff said he worries that previous assumptions about East Antarctica’s stability may not be correct. And that’s important because if the water frozen in East Antarctica melted and that’s a millennia-long process if not longer it would raise seas across the globe more than 160 feet (50 meters). It’s more than five times the ice in the more vulnerable West Antarctic Ice Sheet, where scientists have concentrated much of their research.
Helen Amanda Fricker, co-director of the Scripps Polar Center at the University of California San Diego, said researchers have to spend more time looking at that 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 one of the ice shelves are because once one disappears” it means glaciers melt into the warming water and “some of that water will come to San Diego and elsewhere.”
Scientists had been seeing this particular ice shelf closest to Australia shrink a bit since the 1970s, Neff said. Then in 2020, the shelf’s ice loss sped up to losing about half of itself every month or so, Walker said.
“We probably are seeing the result of a lot of long time increased ocean warming there,” Walker said. “it’s just been melting and melting.”
Still, one expert thinks that only part of East Antarctica is a concern.