British Antarctic Station Has Front Row Seat to Giant Iceberg Calving

For the second time in two years, an enormous chunk of ice broke away from Antarctica’s Brunt Ice Shelf, sending a cyclopean new iceberg floating off into the Weddell Sea.

The U.S. National Ice Center (USNIC) dubbed the new iceberg A-81. The mega-sized ice block measures 28 nautical miles long and 25 nautical miles wide. That’s nearly 1,500 square kilometers — almost as big as Greater London, the BBC reported.

Due to its location on the Brunt Ice Shelf, scientists working at the British Antarctic Survey’s Halley Research Station had an excellent view of the calving. The split in question had been in formation for decades and began to pick up steam in the last few years.

At a mere 20km back from the primary chasm (dubbed Chasm One), the scientists at Halley were motivated to monitor the situation.

When sensors placed at Chasm One began to indicate a dramatic shift in position, researchers knew the time had come.


An analyst working for the USNIC later confirmed the calving with MODIS satellite imagery.

MODIS imagery of A-81 taken on Jan. 24, 2023. Photo: USNIC


A long time coming

This latest ice block, A-81, is the second iceberg to split from the Brunt Ice Shelf in two years.

The first was A-74, a slightly smaller — though no less magnificent — chunk of ice. Prior to A-74, the last significant calving from the Brunt Ice Shelf occurred in 1971.

As the Poles warm, researchers at the British Antarctic Survey (BAS) and elsewhere worry that the Brunt Ice Shelf’s rate of calving might intensify into a major collapse event. So far, that hasn’t happened.

An aerial view of the British Antarctic Survey’s Halley VI Research Station. Photo: British Antarctic Survey


“But these are early days and we’re in a state of heightened vigilance,” BAS glaciologist Professor Dominic Hodgson told the BBC.

The BAS reduced staffing at Halley beginning in Jan. 2017 and currently operates the station in a “summer-only” capacity.

Andrew Marshall

Andrew Marshall is an award-winning painter, photographer, and freelance writer. Andrew’s essays, illustrations, photographs, and poems can be found scattered across the web and in a variety of extremely low-paying literary journals.
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