A Massive Ice Shelf Collapsed In East Antarctica for First Time on Record

After a record-breaking heatwave struck both Antarctica and the Arctic last week, alarming scientists, an ice shelf the size of New York City has broken off of East Antarctica.

The 450-square-mile Conger ice shelf appeared to have broken off of East Antarctica in satellite images captured by the Australian Bureau of Meteorology on March 17, The New York Times reported. It’s estimated to have fallen off between March 14 and 16. 

Though ice shelf breaking is a natural process, scientists fear that the loss of this particular shelf following last week’s alarmingly high temperatures could bode poorly for the continent, and for climate change. This particular ice shelf, which sits close to Australia, had been retreating for several years, but experts remain concerned. It is the first time an ice shelf has collapsed in East Antarctica since satellites began observing the continent decades ago. 

“It was an unhealthy little ice shelf to begin with,” Catherine Walker, an assistant scientist at Woods Hole Oceanographic Institution in Massachusetts told The New York Times, with the caveat that the shelf nonetheless fell sooner than expected. Experts speculate that the presence of an atmospheric river—a plume of warm, moist air that was sent northward by a cold front further south—didn’t help, as temperatures hit 70 degrees higher than average last week. 

Ice shelves are floating sheets of ice that connect to the broader landmass that is Antarctica. They serve as a “safety band” around the coast of the continent, as supporting structures that prevent the flow of ice from the grounded section of the landmass into the ocean. As temperatures warm, melted water percolates through a glacier, slowly oozing into the sea and causing the loss of ice mass. The shelf, however, creates a physical barrier around the land mass, slowing the migration of ice sheets into the ocean. When a shelf breaks off, land masses have an unimpeded flow for recession, which speeds up ice loss and subsequent sea level rise.

Some scientists fear that the loss of the Conger ice shelf thus leaves East Antarctica vulnerable to further ice loss. 

“East Antarctica is starting to change. There is mass loss starting to happen,” Helen Amanda Fricker, professor in the Scripps Institution of Oceanography at the University of California San Diego, told the Associated Press. She told the wire that she feared the long term implications for sea level rise across the globe. 

“We need to know how stable each one of the ice shelves are,” she said. When an ice shelf disappears and glaciers melt, “some of that water will come to San Diego and elsewhere.”