Huge Iceberg Breaks Off from Antarctica’s Brunt Ice Shelf


Kim Hansen, CC BY-SA 3.0 <>, Iceberg_with_hole_near_sanderson_hope_2007-07-28_1 via Wikimedia Commons
Iceberg_with_hole_near_sanderson_hope_2007-07-28_1 via Wikimedia Commons

An iceberg the size of metro London has broken off of Antarctica’s Brunt Ice shelf.

The calving event was confirmed Monday by the British Antarctic Survey (BAS) which first detected growing cracks in the 150-meter-thick ice shelf about a decade ago.

The BAS iceberg calved when the crack known as Chasm-1 fully extended through the ice shelf during a spring tide on Sunday, January 22, between 1900 and 2000 UTC.

The huge iceberg, measuring approximately 600 square miles, has been given the name A81.

The event marks the second major calving from this area in the last two years after an iceberg, known as A74, calved in February 2021. This new iceberg, which is slightly larger than the A74, is expected to follow a similar path in the Antarctic Coastal Current as it drifts west into the Weddell Sea.

BAS scientists study the Brunt Ice Shelf from the Halley Research Station, which in 2016 was relocated several miles inland from Chasm-1 as it widened.

“Our glaciologists and operations teams have been anticipating this event. Measurements of the ice shelf are carried out multiple times a day using an automated network of high-precision GPS instruments that surround the station,” said Professor Dame Jane Francis, Director of BAS. “These measure how the ice shelf is deforming and moving, and are compared to satellite images from ESA, NASA and the German satellite TerraSAR-X. All data are sent back to Cambridge for analysis, so we know what is happening even in the Antarctic winter – when there are no staff on the station, it is dark for 24 hours and the temperature falls below minus 50 degrees C (or -58F).”

Scientists confirm that this latest calving is the result of natural forces and unrelated to climate change.