The world's largest iceberg has broken free

Iceberg A23a separated from the Filchner-Ronne Ice Shelf in 1986. She remained anchored aground in the Weddell Sea for over 30 years. It was only in 2020 that a block of ice with an area of ​​approximately 3,800 square kilometers began its journey through the waters of the Antarctic Ocean.

The fate of the iceberg is being monitored by British scientists from the British Antarctic Survey (BAS). For months this spring, the A23a has been spinning in place in the South Orkney archipelago due to a phenomenon known as the Taylor Column. It occurs in fluids that rotate – such as the ocean, which is influenced by the Coriolis force. What is it about? If the fluid is disturbed by a solid object, such as a bulge on the seabed, under the right conditions this creates a vortex. Objects that enter the range of Taylor's column cannot leave it on their own.

On Friday, BAS scientists reported that the iceberg had started moving north again.

– It's exciting to see the A23a on the road again. We're curious if it will follow the same route as other large icebergs that have separated from Antarctica. And more importantly, what impact will it have on the local ecosystem, said Dr. Andrew Meijers, an oceanographer at BAS.

A year ago, BAS scientists, aboard a state-of-the-art research vessel called RRS Sir David Attenborough, observed an iceberg during a scientific mission in the Weddell Sea as part of the BIOPOLE project. Experts took, among other things, photos of a moving giant block of ice.

It is believed that A23a will eventually leave the Southern Ocean and enter the Atlantic Ocean, where it will encounter warmer waters. When this happens, it will likely break up into smaller icebergs and eventually melt.