Emily Chan
Since 2020, the largest iceberg in the world has been drifting north from Antarctica toward warmer waters.
But now, according to the British Antarctic Survey (BAS), its course has been interrupted after becoming trapped in an ocean vortex.
The iceberg, named A23a, is slowly spinning around and around in a rotating cylinder of water called a Taylor column. It is near the South Orkney Islands, which is located approximately 375 miles northeast of the Antarctic Peninsula. Each day, the iceberg rotates about 15 degrees.
“It’s basically just sitting there, spinning around, and it will very slowly melt as long as it stays there,” said Alex Brearley, an oceanographer at the British Antarctic Survey. “What we don’t know is how quickly it will actually come out of this.”
The iceberg could continue spinning for a year or maybe even two. Experts just aren’t quite sure. Previously, A23a was part of Antarctica.
Now, it is an iceberg the size of Rhode Island. In 1986, it split off from the Filchner-Ronne Ice Shelf on the continent’s northwestern side, taking the Soviet research station Druzhnaya 1 with it. In February 1987, the Soviets traveled to the iceberg to retrieve their equipment.
After that, the iceberg stayed fixed in place for 34 years in the Weddell Sea off the coast of West Antarctica. However, it started to move in 2020. This past November, A23a floated out into the Southern Ocean, moving at a rate of three miles per day.
According to BAS glaciologist Olivia Marsh, A23a had gotten thin enough to lift off from the ocean floor and be carried away by ocean currents.
The iceberg was predicted to take a path known as “iceberg alley” to reach the island of South Georgia in the Atlantic Ocean, propelled forward by the Antarctic Circumpolar Current.
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