The world’s largest iceberg is on the move for the first time in more than three decades, scientists said Friday. At nearly 4,000 square kilometers, the Antarctic iceberg called A23a is about three times the size of New York City.
Since calving off West Antarctica’s Filchner-Ronne Ice Shelf in 1986, the iceberg, which once housed a Soviet research station, has been largely stranded after its base became stuck on the sea floor. of Weddell.
Not anymore. Recent satellite images reveal that the iceberg, which weighs nearly a trillion metric tons, is now moving rapidly past the northern tip of the Antarctic Peninsula, aided by strong winds and currents.
It is rare to see an iceberg of this size in motion, said British Antarctic Survey glaciologist Oliver Marsh, so scientists will be watching its trajectory closely.
As it gains strength, the colossal iceberg will likely be thrown into the Antarctic Circumpolar Current. This will funnel it into the Southern Ocean along a path known as “iceberg alley”, where others of its kind can be found floating in dark waters. It remains to be seen why the iceberg is fleeing towards him.
“Over time, it has probably thinned slightly and gained a little extra buoyancy that has allowed it to rise from the ocean floor and be pushed by ocean currents,” Marsh said. A23a is also among the oldest icebergs in the world.
The A23a may be stranded again on South Georgia Island. That would pose a problem for Antarctic wildlife. Millions of seals, penguins and seabirds breed on the island and feed in the surrounding waters. The A23a could cut off such access. In 2020, another giant iceberg, A68, raised fears that it would collide with South Georgia, crushing marine life to the sea floor and cutting off access to food. Such a catastrophe was finally averted when the iceberg broke into smaller pieces, a possible end for A23a as well.
But “an iceberg of this scale has the potential to survive for quite some time in the Southern Ocean, even though it is much warmer, and could move further north toward South Africa, where it can disrupt shipping,” Marsh said.
