British Antarctic Survey researchers reveal that an iceberg, as massive as 5,000 square kilometers or roughly the size of Delaware, US, would soon break away from the Larsen C ice shelf on the Antarctic Peninsula. The scientists say that climate change caused the thinning of the ice shelf but they are uncertain if the same cause should be blamed on the calving event.

The researchers used seismic techniques to survey the seafloor beneath the ice shelf on Larsen C. “The calving of this large iceberg could be the first step of the collapse of Larsen C ice shelf, which would result in the disintegration of a huge area of ice into a number of icebergs and smaller fragments,” adds glaciologist professor David Vaughan OBE, who is also the Director of Science at British Antarctic Survey.”Because of the uncertainty surrounding the stability of the Larsen C ice shelf, we chose not to camp on the ice this season. Researchers can now only do day trips from our Rothera Research Station with an aircraft nearby on standby.”

“We use regular satellite images provided by the European Sentinel satellites to monitor cracks in the ice shelf. These images are perfect for following these changes since they provide detailed information, day or night and regardless of cloud cover,” added Andrew Fleming, Remote Sensing Manager at British Antarctic Survey.

In a press release, the scientists explained that an ice shelf is a floating extension of land-based glaciers but they do not contribute to sea-level rise directly if they melt. Nevertheless, an ice shelf holds back glaciers flowing down to the coast. When the Larsen A and B, which used to be located further north on the Antarctic Peninsula, ice shelves collapsed back in 1995 and 2002, the glaciers that relied on them entered the ocean and contributed to the rise in sea level.