One of the world’s largest icebergs is moving beyond Antarctic waters, after more than three decades, according to the British Antarctic Survey. The massive iceberg, A23a, is about three times the size of New York City, measuring around 4,000 square kilometres (1,500 square miles).
In 1986, A23a detached from the Antarctic’s Filchner Ice Shelf. But it became stuck to the ocean floor and has remained in the Weddell Sea until now, an Associated Press report said. On 24 November, Andrew Fleming, a remote sensing expert from the British Antarctic Survey, told the BBC that the iceberg has been on the move for the past year and now seems moving faster and past the northern tip of the Antarctic Peninsula, pushed by wind and ocean currents.
“It was grounded since 1986, but eventually it was going to decrease (in size) sufficiently to lose grip and start moving,” Fleming told the BBC. He added that the iceberg’s movement was first spotted movement in 2020. The British Antarctic Survey said it is moving along ocean currents to sub-Antarctic South Georgia.
According to Earth.com, the iceberg has reached the northern tip of the Antarctic Peninsula and is likely to enter the Antarctic Circumpolar Current, following a path through “iceberg alley” towards the South Atlantic.
“Over time it's probably just thinned slightly and got that little bit of extra buoyancy that's allowed it to lift off the ocean floor and get pushed by ocean currents,” British Antarctic Survey glaciologist Oliver Marsh told Reuters.
Scientists will be closely watching this iceberg as it's rare to see one of this size on the move.
In 2020, another massive iceberg, A68, sparked fears of collision with South Georgia. This could have significantly impacted marine life on the sea floor and affected food access, the Reuters report says. This catastrophe was averted when the iceberg broke up into smaller chunks — which could also happen with A23a.
But "an iceberg of this scale has the potential to survive for quite a long time in the Southern Ocean, even though it's much warmer, and it could make its way farther north up toward South Africa where it can disrupt shipping," Marsh told Reuters.
