Satellite data shows entire Conger ice shelf has collapsed in Antarctica

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.

Ice shelves are extensions of ice sheets that float over the ocean, playing an important role in restraining inland ice. Without them, inland ice flows faster into the ocean, resulting in sea level rise.

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.

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

Prof Andrew Mackintosh, head of the school of earth, atmosphere and environment at Monash University, said the Conger ice shelf had significant amounts of melting from the ocean beneath, which could have preconditioned it for collapse.

Surface melt was responsible for the Larsen B ice shelf collapse in 2002.