The world's largest iceberg can destroy penguin habitat

A23 is moving again, and its trajectory puts several ecosystems at risk

by Lorenzo Ciotti
The world's largest iceberg can destroy penguin habitat
© Frances M. Ginter / Staff Getty Images

The world's largest iceberg has begun drifting in Antarctic waters, the British Antarctic Survey reported. Iceberg A23a broke off from the Antarctic Filchner Ice Shelf in 1986, but remained stuck on the ocean floor. Now the iceberg is moving due to strong currents and winds, and its trajectory could spell disaster for a remote island rich in wildlife.

There is a possibility that the A23a iceberg will run aground on South Georgia Island again, which would pose a threat to one of the world's most important ecosystems. The remote island is home to millions of penguins, as well as seals, albatrosses and other rare wildlife.

Of the 30 bird species that breed there, 11 are considered endangered by the International Union for Conservation of Nature (IUCN). A23a, which is also one of the world's oldest icebergs, is moving past the northern tip of the Antarctic Peninsula.

The first movements, in reality, had already been observed in 2020, but in the last year the iceberg has increased its speed in a northerly direction and is about to pass the northern tip of the Antarctic Peninsula.

The world's largest iceberg could destroys a most important ecosystem

Andrew Fleming, remote sensing expert at the British Antarctic Survey, told BBC: "I asked a couple of colleagues whether there was any change in platform water temperatures that could have caused this phenomenon, but the consensus is simply that its time had come.

The iceberg had been stuck since 1986, but we knew that sooner or later it would get smaller enough to unfreeze and start moving." The researchers who are monitoring its movements, among other things, have understood that the route of A-23a will be similar to that of other icy giants coming from the Weddell Sea area.

The iceberg, essentially, should be captured by the Antarctic Circumpolar Current.