emirates7 - Nearly four decades after breaking away from Antarctica, one of the largest and oldest icebergs ever recorded, known as A23a, is now rapidly disintegrating in warmer waters and could vanish within weeks.
Earlier this year, the “megaberg” weighed just under a trillion tonnes and spanned more than twice the size of Greater London, making it an unprecedented giant at the time. Its immense size even briefly posed a threat to penguin feeding grounds on a remote South Atlantic island, though it eventually drifted onward.
Today, the iceberg has shrunk to less than half its original size but still covers 1,770 square kilometres and stretches 60 kilometres at its widest point, according to AFP analysis of Copernicus satellite images. In recent weeks, enormous chunks—some as large as 400 square kilometres—have broken off, with smaller fragments still large enough to endanger ships littering the surrounding sea.
Andrew Meijers, a physical oceanographer at the British Antarctic Survey, told AFP that the iceberg is “breaking up fairly dramatically” as it drifts north. He added, “It’s basically rotting underneath. The water is far too warm for it to survive. It’s constantly melting. I expect it won’t be really identifiable within a few weeks.”
A history of survival
A23a calved from the Antarctic shelf in 1986 but remained grounded in the Weddell Sea for over 30 years. It finally broke free in 2020, carried along the South Atlantic “iceberg alley” by the Antarctic Circumpolar Current.
In March, the iceberg ran aground near South Georgia island, raising concerns about potential disruptions to penguin and seal colonies feeding their young. It dislodged in late May and continued north, sometimes covering up to 20 kilometres a day, according to AFP’s satellite analysis. Exposed to warmer waters and massive waves, A23a has rapidly fragmented.
Meijers noted scientists were “surprised” by how long the iceberg had held together. “Most icebergs don’t make it this far. This one’s really big, so it has lasted longer and traveled further than others.”
Ultimately, icebergs are “doomed” once they leave Antarctica’s frigid waters. While iceberg calving is a natural process, scientists warn that the rate of ice loss from Antarctica is accelerating, likely due to human-induced climate change.
Earlier this year, the “megaberg” weighed just under a trillion tonnes and spanned more than twice the size of Greater London, making it an unprecedented giant at the time. Its immense size even briefly posed a threat to penguin feeding grounds on a remote South Atlantic island, though it eventually drifted onward.
Today, the iceberg has shrunk to less than half its original size but still covers 1,770 square kilometres and stretches 60 kilometres at its widest point, according to AFP analysis of Copernicus satellite images. In recent weeks, enormous chunks—some as large as 400 square kilometres—have broken off, with smaller fragments still large enough to endanger ships littering the surrounding sea.
Andrew Meijers, a physical oceanographer at the British Antarctic Survey, told AFP that the iceberg is “breaking up fairly dramatically” as it drifts north. He added, “It’s basically rotting underneath. The water is far too warm for it to survive. It’s constantly melting. I expect it won’t be really identifiable within a few weeks.”
A history of survival
A23a calved from the Antarctic shelf in 1986 but remained grounded in the Weddell Sea for over 30 years. It finally broke free in 2020, carried along the South Atlantic “iceberg alley” by the Antarctic Circumpolar Current.
In March, the iceberg ran aground near South Georgia island, raising concerns about potential disruptions to penguin and seal colonies feeding their young. It dislodged in late May and continued north, sometimes covering up to 20 kilometres a day, according to AFP’s satellite analysis. Exposed to warmer waters and massive waves, A23a has rapidly fragmented.
Meijers noted scientists were “surprised” by how long the iceberg had held together. “Most icebergs don’t make it this far. This one’s really big, so it has lasted longer and traveled further than others.”
Ultimately, icebergs are “doomed” once they leave Antarctica’s frigid waters. While iceberg calving is a natural process, scientists warn that the rate of ice loss from Antarctica is accelerating, likely due to human-induced climate change.