The world’s largest iceberg has been sitting on the ocean floor for decades, but has recently begun to move again after spinning in place, according to the British Antarctic Survey (BAS).
Scientists say the giant A23a iceberg has been freed from its position north of the South Orkney Islands and is now floating in the Southern Ocean.
“It’s exciting to see A23a starting to move again after being stagnant for a while. We are uncertain whether it will follow the same route taken by other large icebergs that have calved off the coast of Antarctica. We’re interested. And more importantly, what impact does this have on the local ecosystem?” said BAS oceanographer Dr Andrew Myers.
The iceberg, known as A23a, broke off from the Filchner Ice Shelf in Antarctica in 1986. However, it stuck to the ocean floor and remained in the Weddell Sea for many years.
Scientists expect A23a to continue its journey into the Southern Ocean, following the Antarctic Circumpolar Current, likely heading for the subantarctic island of South Georgia. The area is expected to encounter warmer ocean water, break up the iceberg into smaller icebergs, and eventually melt.
The iceberg is approximately three times the size of New York City and more than twice the size of Greater London, covering an area of approximately 4,000 square kilometers (1,500 square meters).
Last year, a British polar research vessel encountered an A23a. This was a “lucky” encounter, allowing scientists to collect seawater samples around a huge mountain range drifting from the Southern Ocean.
On his first scientific mission to Antarctica, RRS Sir David Attenborough passed a huge iceberg near the tip of the Antarctic Peninsula.
It started drifting in recent months and was assisted by wind and ocean currents as it moved into the Southern Ocean.
