Ice Shelf Collapses in Previously Stable East Antarctica
Scientists were concerned Friday that an ice shelf in East Antarctica the same size as New York City had collapsed. This is an area thought long to have been stable and unaffected by climate change.
Satellite imagery captured the event via satellite. It was the first time ever that an ice shelf had fallen in this region. The collapse occurred during a rare warm spell in East Antarctica last week, when temperatures rose more than 70°C (40 Celsius) above normal. Satellite photos show the area had been shrinking rapidly the last couple of years, and now scientists wonder if they have been overestimating East Antarctica’s stability and resistance to global warming that has been melting ice rapidly on the smaller western side and the vulnerable peninsula.
Catherine Walker, an ice scientist at the Woods Hole Oceanographic Institute, said that the ice shelf covering 460 miles (1200 km) was responsible for holding the Conger glaciers and Glenzer glaciers in warmer waters. It collapsed between March 14-16. It is alarming that scientists have not seen such a thing in this region of the continent before, she stated.
“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. This is not significant. 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 Scripps Polar Center University of California San Diego said more research is needed to focus on that region.
“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.”
However, one expert believes only a small portion of East Antarctica should be considered a problem.
“Most of East Antarctica is relatively secure, relatively invulnerable and there are sectors in it that are vulnerable,” said British Antarctic Survey geophysicist Rob Larter. “The overall effect of climate change around East Antarctica is it’s chipping away at the edges of the ice sheets in some places, but it’s actually adding more snow to the middle.”
Last week, what’s called an atmospheric river dumped a lot of warm air — and even rain instead of snow — on parts of East Antarctica, getting temperatures so far above normal that scientists have spent the last week discussing it. The closest station to the collapsed ice shelf is Australia’s Casey station, about 180 miles (300 kilometers) away and it hit 42 degrees (5.6 degrees Celsius), which was about 18 degrees (10 degrees Celsius) warmer than normal.
And that, Walker said, “probably is something like, you know, the last straw on the camel’s back.”
Fricker, who has explored a different more stable East Antarctic ice shelf, said an ice shelf there “is the quietest most serene place you can imagine.”
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