World’s largest iceberg on the move again after months spinning on the spot

The world’s largest iceberg is on the move again after decades of being grounded on the seafloor and more recently spinning on the spot, according to the British Antarctic Survey (BAS).

The mega A23a iceberg has broken free from its position north of the South Orkney Islands and is now drifting in the Southern Ocean, scientists said.

“It’s exciting to see A23a on the move again after periods of being stuck. We are interested to see if it will take the same route the other large icebergs that have calved off Antarctica have taken. And more importantly what impact this will have on the local ecosystem,” Dr Andrew Meijers, an oceanographer at the BAS, said.

The iceberg, known as A23a, split from the Antarctic’s Filchner Ice Shelf in 1986. But it became stuck to the ocean floor and had remained for many years in the Weddell Sea.

Scientists anticipate that A23a will continue its journey into the Southern Ocean following the Antarctic Circumpolar Current, which is likely to drive it towards the sub-Antarctic island of South Georgia. In that region it will encounter warmer water and is expected to break up into smaller icebergs and eventually melt.

open image in gallery

open image in gallery

The iceberg is about three times the size of New York City and more than twice the size of Greater London, measuring around 4,000sqkm (1,500sqm).

Last year Britain’s polar research ship crossed paths with A23a, a “lucky” encounter that enabled scientists to collect seawater samples around the colossal berg as it drifts out of Antarctic waters.

The RRS Sir David Attenborough, which was on its way to Antarctica for its first scientific mission, passed the mega iceberg near the tip of the Antarctic Peninsula.

It began drifting in recent months, and moved into the Southern Ocean, helped by wind and ocean currents.