The giant iceberg, whose rift began to open in 2012, broke away from the Brunt Ice Shelf in Antarctica — and glaciologists say the detachment would not have happened due to climate change. ESA’s Copernicus program’s Sentinel satellites saw the detachment, and the European Space Agency said satellite imagery confirms a giant iceberg, about five times the size of Malta, has finally detached from the ice shelf. ESA reported today that the new mountain – which the British Observatory Bas announced last Sunday 22nd – has extended fully northwards, severing the western part of the Ice Shelf. The crack that caused the iceberg to break off was first discovered in 2012 after being dormant for several decades. After several years in which the ice masses “remained stuck” on the Brunt Shelf, imagery from the Copernicus Sentinel missions has now “visually confirmed the calving event,” the ESA said.
Glaciologists have monitored the giant iceberg for years, so much so that the European Space Agency has even spoken of it as a “birth,” stating that the timing of the detachment “although unexpected was long-foreseeable. For years glaciologists have monitored the numerous ice rifts and chasms that formed in the thick Brunt Ice Shelf bordering the coast of Coats Land in Antarctica’s Weddell Sea sector. It was only a matter of time before Chasm 1, which had lain dormant for decades, first encountered Halloween Crack in Halloween 2016. ESA advises that the new iceberg is likely to be named A-81, while the smaller northern piece is likely to be identified as A-81A or A-82. Icebergs, ESA explains, are traditionally identified by a capital letter indicating the Antarctic quadrant in which they were originally sighted, followed by a sequential number and then, if the iceberg breaks into smaller pieces, by a sequential lower-case letter. The split was first reported by the Bas-British Antarctic Survey as occurring between 1900 and 2000 UTC on Jan 22 during a spring tide. Bas’ Halley VI research station, where glaciologists monitored the behavior of the ice shelf, was unaffected by the calving event. ESA recalls that the research station was moved to a safer location in 2017 after the ice shelf was deemed unsafe. The station is currently about 20km from the breaking point and currently 21 people work at the station maintaining the feeders and facilities that keep the science experiences going throughout the winter.
“The detachment of the iceberg has finally happened,” articulates European Space Agency researcher and ice expert Mark Drinkwater, who welcomed the news of the detachment of the giant iceberg, five times the size of Malta, and the event, according to glaciologist Dominic Hodgson from British Antarctic Survey “is not linked to climate change”. Drinkwater, in a post on esa.int, notes that “after several years of monitoring the ‘calving’ of the iceberg, the long-awaited separation of the Brunt A81 iceberg has finally occurred”. “The northward propagation of Chasm 1 and Bas’ timely decision to move Halley Base to safer ground have been accompanied by perhaps the most detailed and longest-running investigation into the events leading up to the natural calving of an Antarctic Ice Shelf,” explained the scientist. “Thanks to Copernicus, combined with in situ and airborne measurements from the British Antarctic Survey, the safety of Halley Base has been maintained. Meanwhile, Drinkwater continues, the combination of Sentinel-2 summer imagery and the availability of year-round and winter surveillance by Sentinel-1 radar has put the deformation and propagation pattern of an ice shelf fracture under the global public microscope.”
For Dominic Hodgson, Bas glaciologist, “This ‘calving’ was to be expected and is part of the natural behavior of the Brunt Ice Shelf. It has nothing to do with climate change. Our scientific and operational teams continue to monitor the ice shelf in real time to ensure it is safe and to maintain the delivery of the science we are undertaking at Halley. 0ESA and Bas scientists report that “the calving of an iceberg from an ice shelf is followed by an adjustment in ice flow into the ice shelf.” acceleration, it could affect the behavior of other cracks in the area,” they finally add.