According to observations from the British Antarctic Survey (BAS) at the Halley Research Station, a massive iceberg has separated from the Brunt Ice Shelf in Antarctica. Reports say the calved iceberg measures 1270 km² in size.
The calving comes after roughly a decade of waiting, as BAS scientists first noticed cracks in the 150-meter thick ice shelf years ago. However, it became obvious that the calving would take place in the near future back in November of 2020 when a new large crack called the North Rift appeared. The crack eventually widened enough to break off from the ice shelf on the morning of February 26th.
“Our teams at BAS have been prepared for the calving of an iceberg from Brunt Ice Shelf for years. We monitor the ice shelf daily using an automated network of high-precision GPS instruments that surround the station; these measure how the ice shelf is deforming and moving. We also use satellite images from ESA, NASA, and the German satellite TerraSAR-X. All the data are sent back to Cambridge for analysis, so we know what’s happening even in the Antarctic winter, when there are no staff on the station, it’s pitch black, and the temperature falls below minus 50 degrees C (or -58F),” said BAS director Jane Francis.
As to what is will happen next, Francis adds that while it is unclear how the iceberg will move, the extensive monitoring of the ice shelf by the BAS, European Space Agency, and NASA, will provide precise updates as events unfold. “Over the coming weeks or months, the iceberg may move away; or it could run aground and remain close to Brunt Ice Shelf,” notes Francis. “Halley Station is located inland of all the active chasms, on the part of the ice shelf that remains connected to the continent. Our network of GPS instruments will give us early warning if the calving of this iceberg causes changes in the ice around our station.”
“This is a dynamic situation. Four years ago, we moved Halley Research Station inland to ensure that it would not be carried away when an iceberg eventually formed. That was a wise decision. Our job now is to keep a close eye on the situation and assess any potential impact of the present calving on the remaining ice shelf. We continuously review our contingency plans to ensure the safety of our staff, protect our research station, and maintain the delivery of the science we undertake at Halley,” comments BAS Director of Operations, Simon Garrod.
The researchers add that there is currently no evidence to suggest that climate change was an active factor in the calving of the iceberg, saying that such sea ice changes in this area are natural and relatively common.