Ice Shelf Collapses Following Antarctic Heat Wave

March 25, 2022

Remember, an ice “shelf” is the tongue of ice that floats out on the sea surface in front of a larger, more massive ice “sheet”. The Sheet is where the big mass of ice is, and they move slowly (in human terms), but the shelf is often what buttresses the sheet against more rapid movement.

This event is notable because it takes place in East Antarctica, where the greatest volume of ice is locked up, and where we have the least observations.
More information needed.

Guardian:

An ice shelf about the size of Rome has completely collapsed in East Antarctica within days of record high temperatures, according to satellite data.

The Conger ice shelf, which had an approximate surface area of 1,200 sq km, collapsed around 15 March, scientists said on Friday.

East Antarctica saw unusually high temperatures last week, with Concordia station hitting a record temperature of -11.8C on 18 March, more than 40C warmer than seasonal norms. The record temperatures were the result of an atmospheric river that trapped heat over the continent.

Dr Catherine Colello Walker, an earth and planetary scientist at Nasa and the Woods Hole Oceanographic Institution, said though the Conger ice shelf was relatively small, “it is one of the most significant collapse events anywhere in Antarctica since the early 2000s when the Larsen B ice shelf disintegrated”.

“It won’t have huge effects, most likely, but it’s a sign of what might be coming,” Walker said.

The Conger ice shelf had been shrinking since the mid-2000s, but only gradually until the beginning of 2020, Walker said. By 4 March this year, the ice shelf appeared to have lost more than half its surface area compared to January measurements of around 1,200 sq km.

Peter Neff, a glaciologist and assistant research professor at the University of Minnesota, said that to see even a small ice shelf collapse in East Antarctica was a surprise.

“We still treat East Antarctica like this massive, high, dry, cold and immovable ice cube,” he said. “Current understanding largely suggests you can’t get the same rapid rates of ice loss [as in West Antarctica] due to the geometry of the ice and bedrock there.”

“This collapse, especially if tied to the extreme heat brought by the mid-March atmospheric river event, will drive additional research into these processes in the region.”

Satellite data from the Copernicus Sentinel-1 mission showed that movement of the ice shelf began between 5 and 7 March, Neff said.

My question would be, did a massive amount of melting during the recent heat wave send torrents of meltwater into crevasses around the shelf, creating the hydraulic pressure that made it suddenly fail?

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