The world’s largest iceberg moved for the first time in more than three decades, scientists said Friday.
At almost 4,000 square kilometers, the Antarctic iceberg called A23a is about three times larger than New York City.
Since breaking free from the Filchner-Ronne Ice Shelf in West Antarctica in 1986, the iceberg – once home to a Soviet research station – has been largely stranded after its base became trapped at the bottom of the Weddell Sea.
Recent satellite images reveal that the volcano, which weighs nearly a trillion metric tons, is now speeding past the northern tip of the Antarctic Peninsula. These large boulders were aided by strong winds and currents.
Thwaites Glacier in Antarctica is seen in this undated NASA image. (Photo: REUTERS/NASA via Reuters)
British Antarctic Survey glaciologist Oliver Marsh said the phenomenon was so rare that scientists would be watching its trajectory closely.
As its speed increases, the giant iceberg will likely be thrown into the Antarctic Rift Current. That would lead it toward the Southern Ocean via a path known as the “iceberg corridor,” where other similar icebergs can be found floating in the dark waters.
Why the iceberg managed to escape now remains to be seen.
“Over time, it probably thins out a little and gets a little extra buoyancy that allows it to lift off the sea floor and be pushed along by ocean currents,” Marsh said. A23a is also one of the oldest icebergs in the world.
There is a possibility that A23a could again become stranded on South Georgia Island. This will be a problem for wildlife in Antarctica. Millions of seals, penguins and seabirds breed on the island and feed in the surrounding waters. The giant A23a can cut off that access.
In 2020, another giant iceberg, A68, raised fears that it would collide with South Georgia, destroying marine life on the seabed and cutting off access to food. Such a disaster was finally averted when the iceberg broke into small pieces.
But “an iceberg of this size has the potential to remain for quite a long time in the Southern Ocean, despite much warmer temperatures, and could move further north towards South Africa, disrupting shipping,” Marsh said. (ah/ft)