Antarctica: Iceberg 'as big as the Isle of Wight' breaks off the icy continent - near British research station
The new iceberg ‘calved’ from the 150-metre-thick Brunt Ice Shelf, near a British research station.
Antarctica: Iceberg 'as big as the Isle of Wight' breaks off the icy continent - near British research station
A huge iceberg almost the size of the Isle of Wight has broken off from an Antarctic ice sheet.
The British Antarctic Survey says the iceberg, which is likely to be named A83, is an enormous 380 square-kilometres. It broke off from the 150-metre thick Brunt Ice Shelf in the early hours of Monday (20 May) morning, after a new 14-kilometre chasm formed at a 90-degree angle to the ‘Halloween Crack’, which has been there since 2016.
It follows a long period of weakening of the ice at the McDonald Ice Rumples, an area bordering Antarctica’s Weddell Sea. The break off is the third major iceberg to ‘calve’ from this area in the last four years - and has taken place around a decade after scientists at British Antarctic Survey (BAS) first detected vast cracks creeping through in the ice.
The Brunt Ice Shelf is home to the British Antarctic Survey’s Halley Research Station. However, BAS scientists monitoring the behaviour of the ice shelf believe it remains stable for now, and say the station is currently unmanned - so they don’t expect they will need to respond to this latest event.
Glaciologist Dr Oliver Marsh first detected the iceberg breaking off this week using GPS equipment. “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.”
But, he said the new icebergs falling off are not thought to be linked to climate change - unlike many of Antarctica’s other sea ice issues. “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.”
In 2016, BAS relocated the Halley Research Station 23 km inland of Chasm-1 as a precaution, after experts noticed it had began to widen. Since 2017, staff have been deployed to the station only during the Antarctic summer (between November to March). Currently the station is unstaffed, but a new team would arrive in November.
However, Swansea University Antarctic ice shelf expert, Professor Adrian Luckman, said that so many icebergs falling off in a short space of time was somewhat worrying. “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.”
He continued: “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.”