As it’s making its way towards the Southern Ocean, the largest iceberg in the world, A23a, has made a noteworthy break from its still state that lasted for three decades.
This huge Antarctic iceberg, which is about 4,000 square kilometers in size—roughly three times the area of New York City—has remained mostly static since it broke off the Filchner-Ronne Ice Shelf in West Antarctica in 1986.
With strong winds and ocean currents pushing it, recent satellite footage shows that it is currently rapidly moving past the northern tip of the Antarctic Peninsula.
Oliver Marsh, a glaciologist of the British Antarctic Survey, notes how uncommon it is to see an iceberg this size floating and says scientists will be constantly tracking its trajectory.
A23a is expected to gain rate and accomplish the Antarctic Circumpolar Current, which will propel it via “iceberg alley,” where similar ice formations frequently occur and towards the Southern Ocean.
The reason for A23a’s abrupt movement is yet uncertain. Marsh believes that the iceberg may have thinned over time and gained more buoyancy, allowing it to lift off the ocean floor and be carried by currents. A23a is also one of the oldest icebergs in the world.
A23a could end up grounded once more, possibly at South Georgia Island, which could cause issues for the nearby wildlife. The huge iceberg could hinder millions of seals, penguins, and seabirds from accessing the area, to breed and feed.
A23a’s massive size raises concerns about how long it will last in the Southern Ocean; it might split up into tiny parts like its predecessor A68 in 2020, possibly affecting shipping lanes and reaching as far north as South Africa.