A new satellite image released by NASA has captured the “ongoing disintegration” of Iceberg A-23a in Antarctica, which was the world’s largest iceberg before it was reported to be shrinking rapidly earlier this month.
The image, captured by NASA’s Terra satellite on September 11, “signals the imminent demise of one enormous, long-lived berg,” the space agency said in a statement Thursday.
Iceberg A-23A (also known as A23a) previously spanned around 3,643 square kilometers (about 1,062 nautical miles)—roughly the size of Rhode Island—as of January, according to the National Environmental Satellite, Data and Information Service. It has already lost around two-thirds of its area since it began drifting north from Antarctica several years earlier.
At the time of the latest image, two large fragments that calved from A-23a—Iceberg A-23g and Iceberg A-23i—were reported to span 324 square kilometers (125 square miles) and 344 square kilometers (133 square miles), respectively, NASA said.
After breaking from the Filchner Ice Shelf in 1986, A-23a lodged on the seafloor of the southern Weddell Sea for decades before breaking free in the early 2020s, and it began drifting northward.
It became caught in a rotating ocean vortex in the Drake Passage in March 2024, which led to it becoming lodged on the shallow coastal shelf south of South Georgia Island in May 2025. After freeing itself again, the iceberg drifted to its current location north of the island on what could be “its final ride,” NASA said.
Earlier this month, A-23a was reported to be “rapidly breaking up, and shedding very large chunks,” Andrew Meijers, an oceanographer at the British Antarctic Survey (BAS), told CNN.
A-23a was said to have shrunk to nearly 1,700 square kilometers (around 656 square miles), according to Meijers.
The recent disintegration led to the loss of its title as the world’s largest iceberg. That title is now held by Iceberg D15a, which is around 3,000 square kilometers (1,158 square miles) and is “fairly static on the Antarctic coast near the Australian Davis base,” Meijers said.
Similar to the fate of other large bergs that have ventured into “iceberg alley,” NASA says A-23a “will eventually succumb to the relentless effects of warmer air and water.”
According to NASA, Antarctica is losing ice mass at an average rate of about 136 billion tons per year, while Greenland is losing about 267 billion tons per year, adding to sea-level rise.
“This is important because the ice sheets of Greenland and Antarctica store about two-thirds of all the fresh water on Earth,” NASA noted, adding: “They are losing ice due to the ongoing warming of Earth’s surface and ocean. Meltwater coming from these ice sheets is responsible for about one-third of the global average rise in sea level since 1993.”
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