Satellite Image Reveals Rapid Disintegration of World’s Former Largest Iceberg A23a

A recent image captured by the Copernicus Sentinel-2 satellite has provided a striking view of iceberg A23a in the South Atlantic Ocean, which once held the title of the world’s largest iceberg. The clear, cloud-free photograph reveals early indicators that the iceberg is on the brink of complete disintegration. Originally calved from the Filchner-Ronne ice shelf in West Antarctica in 1986, A23a measured an impressive 4,000 square kilometers—over three times the size of Rome—making it the largest iceberg at the time.

For decades, A23a remained grounded on the ocean floor until it broke free in 2020, subsequently floating into the Weddell Sea. By November 2023, it had begun to drift rapidly northward, propelled by ocean currents and winds, eventually reaching the warmer waters of the South Atlantic. The iceberg journeyed approximately 2,000 kilometers to the vicinity of South Georgia Island by May 2025, where it began to fragment significantly.

Throughout 2025, A23a exhibited considerable deterioration, breaking apart into smaller ice masses and significantly diminishing in size. A recent image taken on December 20, 2025, shows the iceberg positioned approximately 150 kilometers northwest of South Georgia, surrounded by a variety of smaller icebergs. Although A23a has lost around three-quarters of its original surface area, it still remains one of the largest icebergs in open waters, currently spanning about 1,000 square kilometers.

The visible bright blue patches on the iceberg and adjacent smaller icebergs indicate the presence of meltwater ponds, marking the rapid decline of A23a. This type of disintegration is common for icebergs that venture into warmer northern waters, where elevated sea temperatures and weather conditions contribute to their breakdown. As A23a continues its journey into even warmer oceanic regions, experts anticipate it will follow the path of other massive icebergs that have previously met a similar fate in these waters.