The world’s largest iceberg moves towards the Southern Ocean

by Gloria Dickie

The world’s largest iceberg is moving for the first time in thirty years, scientists announced Friday.

With an area of ​​almost 4,000 km², the Antarctic iceberg A23a is approximately three times larger than New York City.

Since breaking away from West Antarctica’s Filchner-Ronne Ice Shelf in 1986, the iceberg that once housed a Soviet research station has remained largely stuck after its submerged portion collapsed. is immobilized on the bottom of the Weddell Sea.

But recent satellite images have revealed that the nearly billion-ton iceberg is now drifting rapidly past the northern tip of the Antarctic Peninsula, pushed by strong winds and currents.

It’s rare to see an iceberg of this size moving, said Oliver Marsh, a glaciologist at the British Antarctic Survey.

As it gains strength, the colossal iceberg will likely be thrown into the Antarctic Circumpolar Current, which will then carry it toward the Southern Ocean, on a path known as the “iceberg corridor” where other icebergs of this type float in dark waters.

The reason for his trip is currently unknown.

“Over time, it probably thinned out slightly and gained that little extra buoyancy that allowed it to rise off the ocean floor and be pushed around by ocean currents,” Oliver Marsh said.

A23a is also one of the oldest icebergs in the world.

It is possible that it will run aground on the island of South Georgia, located in the southern Atlantic Ocean, which could pose a problem for the flora and fauna of Antarctica. Millions of seals, penguins and seabirds breed on the island and forage in the surrounding waters.

In 2020, another giant iceberg, A68, threatened to collide with South Georgia Island but ultimately broke up into smaller pieces beforehand. A fate that A23a could also experience.

(Reporting by Gloria Dickie in London, French version by Nathan Vifflin, edited by Blandine Hénault)