Published on : Wednesday, March 3, 2021
A massive iceberg almost the size of Greater London has recently broken away from the Antarctic ice shelf near a British research station, as reported by the British Antarctic Survey (BAS). The research body said the iceberg measuring 1,270 square kilometres (490 square miles) had broken off from the 150-metre-thick Brunt Ice Shelf in a process called “calving” almost a decade after scientists at BAS first noticed vast cracks formed in the shelf.
The first indication that a calving event was imminent came in November 2020 when a new chasm called North Rift headed towards another large chasm near the Stancomb-Wills Glacier Tongue 35 kms away, BAS said in a statement. North Rift is the third major crack through the ice shelf to become active in the last decade. During January, this rift pushed northeast at up to 1 km per day, cutting through the 150-metre-thick floating ice shelf. The iceberg was formed when the crack widened several hundred metres in a few hours, releasing it from the rest of floating ice shelf.
Britain’s Halley VI Research Station monitors the state of the vast floating ice shelf daily. The base’s 12-person team left earlier this month, as they leave the base uninhabited in winter due to the unpredictable conditions. While they are away, data from GPS instruments at the site goes to a centre in Cambridge, eastern England, for analysis. Icebergs naturally break off from Antarctica into the ocean in a process accelerated by climate change. The BAS informed that in this case, there is no evidence that climate change has played a significant role in the recent event. The mobile research base relocated inland for safety reasons in 2016-2017 as cracks in the ice threatened to cut it off. The glaciologists said the latest event is unlikely to affect the station’s current location.
Jane Francis, Director, British Antarctic Survey said that the teams at BAS have been prepared for the calving of an iceberg from Brunt Ice Shelf for years. It was also informed that over the coming weeks or months, the iceberg may move away; or it could run around and remain close to Brunt Ice Shelf. She mentioned that the ice shelf is monitored daily using an automated network of high-precision GPS instruments that surround the station, and measure how the ice shelf is deforming and moving. She said that satellite images from ESA (European Space Agency), NASA and the German satellite TerraSAR are also used for monitoring.