The Conger Ice Shelf collapsed after temperatures in East Antarctica hit 40C above normal earlier this month.
An East Antarctic ice shelf disintegrated this month after a period of extreme heat in the region, scientists have said.
Satellite images show the 1,200 km2 (463 sq mi) Conger Ice Shelf collapsed completely on or around March 15.
“Possible it hit its tipping point after the #Antarctic #AtmosphericRiver and the heatwave too?” NASA Earth and planetary scientist Catherine Colello Walker asked on Twitter on Friday, sharing images of a white expanse splintering above the dark ocean.
Ice shelves, permanent floating patches of ice attached to land, take thousands of years to form and act as levees holding back snow and ice that would otherwise flow into the ocean, causing the rise seas.
The March heat wave, with temperatures reaching 40°C (70°F) above normal in parts of East Antarctica, was linked to the atmospheric fluvial phenomenon, said Peter Neff, a glaciologist at the University of Minnesota.
This process creates columns hundreds of miles long that carry water vapor from the tropics, creating an effect that Neff described as “a firehose of moisture.”
“The [Antarctic] the climate is incredibly variable, but that was off the scale,” Neff said. “It was at least twice as extreme of a warming event as we expected.”
New @usnatice– named icebergs resulting from the complete collapse of the East Antarctica Conger Ice Shelf (~1200 km2) on/around March 15, seen as a combo of #Landsat and #MODIS imagery. #CongerIceShelf #Antarctic @helenafricker @jdmillstein https://t.co/16JtKcXQPY pic.twitter.com/lSKMNgRgNi
—Catherine Colello Walker (@CapComCatWalk) March 24, 2022
Temperatures in the area are usually around -51C (-60F) at this time of year, but were around -12C (-10F) earlier this month.
They are now back to normal, Neff said.
Surrounded by vast oceans and buffered by winds that tend to protect it from large intrusions of warm air, the frozen continent is responding more slowly to climate change than the Arctic, which is warming three times faster than the rest of the world.
Over the past century, East Antarctica has barely warmed, but some regions have been affected and the continent has lost an average of 149 billion tonnes of ice per year from 2002 to 2020, according to NASA. The loss of the Conger Ice Shelf is the latest example of the changes underway.
“This poor little ice shelf was hanging on for dear life in this very hot coastal climate and it had been thinning and deteriorating over the past few decades,” Neff said.
The Conger Plateau broke up long before the heat wave, and its disappearance shows that the Antarctic system is sensitive to atmospheric changes, but the event itself is not of concern, said Ted Scambos, senior researcher at the University. from Colorado to Boulder.
A small glacier behind which Conger was sitting could now be flowing faster and dumping some more ice into the sea, he said.
“If it was in your backyard, it would be huge…but by Antarctic standards and by sea level standards, it’s a tiny area,” he said.