The world’s largest iceberg is moving again after being stuck in a vortex for most of the year.
A23a covers 3,800 square kilometers, which is more than twice the size of Greater London, and is 400 meters thick. In 1986 it broke away from Antarctica, but soon became stuck just off the coast.
The iceberg’s depth caused it to become stuck at the bottom of the Weddell Sea, part of the Southern Ocean, where it remained static for more than thirty years.
It began moving north in 2020 but has been spinning in place since spring after becoming trapped in a rotating water column near the South Orkney Islands.
[BBC]
On Friday, the British Antarctic Survey (BAS) said it was now drifting further north.
Dr. Andrew Meijers, oceanographer at BAS, said: “It is exciting to see the A23a moving again after periods of being stuck.
“We are curious to see if it will follow the same route as the other large icebergs that have calved off the coast of Antarctica.”
It is thought that A23a will eventually leave the Southern Ocean and enter the Atlantic Ocean, where it will encounter warmer waters and break up into smaller icebergs and eventually melt.
Dr. Meijers and the BAS investigate the impact of icebergs on local ecosystems after they have passed through them.
[BBC]
A year ago, researchers aboard the RRS Sir David Attenborough collected data from the water around A23a.
Laura Taylor, a biogeochemist who was part of the crew, said: “We know that these giant icebergs can provide nutrients to the waters they pass through, creating thriving ecosystems in otherwise less productive areas.
“What we don’t know is what difference certain icebergs, their size and their origins can make in that process.”
