A large iceberg has broken away from the area of Antarctica that houses the UK's Halley research facility, as per a report in the BBC. The iceberg, which measures some 380 sq km, roughly the size of the UK's Isle of Wight and nearly as big as Amsterdam, is the third iceberg to have calved near the base in the last three years. The iceberg broke off after a crack suddenly appeared on the ice shelf a few weeks ago. The final break happened in the early hours of May 20.
The iceberg calved after a 14-kilometre-long split emerged at 90 degrees from the existing Halloween Crack. This comes after a long period of ice weakening at McDonald's Ice Rumples, according to the British Antarctic Survey. Notably, there is no evidence that the calvings are related to climate change.
As per the BBC, the British Antarctic Survey moved the research facility in 2017 due to concerns over the way ice was behaving. Its buildings were moved using skis to a location away from any potential danger. Halley sits on the Brunt Ice Shelf, a glacier protrusion that has slipped into the Weddell Sea from the continent. This shelf is going through a very dynamic phase right now, and it will periodically drop icebergs at its forward edge.
Moreover, the staff members have been deployed to the research centre only during the Antarctic summer, which begins in November and lasts till March. A new team will return to Halley in November.
Dr Oliver Marsh, a glaciologist with four seasons of experience on the Brunt Ice Shelf, initially discovered the calving using GPS technology. "This calving was expected since the appearance of Halloween Crack eight years ago and reduces the total area of the ice shelf to its smallest extent since monitoring began," he said.
"Tabular iceberg calving is part of the natural behaviour of ice shelves but often causes large changes in ice shelf geometry and can impact local ocean circulation. Our science 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 undertake at Halley," he continued.
Professor Adrian Luckman, a professor at Swansea University, who studies Antarctic ice shelves, added, "Antarctica's floating ice shelves grow gradually by ice flow and shrink episodically by iceberg calving. The balance between these two processes impacts their ability to hold back ice on land. It is concerning, therefore, that even in this relatively cold sector of Antarctica there have now been three large iceberg calvings in the last 3-4 years. The Brunt Ice Shelf is providing plenty of data to help us understand the calving process and predict the future evolution of these important ice bodies."
