Iceberg A23a breaks apart north of South Georgia Island

Once the world’s largest iceberg, A23a calved from Antarctica’s Filchner–Ronne Ice Shelf in 1986. After spending decades grounded, it re-entered circulation, approaching South Georgia island at the end of 2024.

After running aground in shallow waters off of the island in March 2025, it moved along the eastern flank, where it started to fragment north of South Georgia toward the end of August. On 14 September 2025, one of the Copernicus Sentinel-3 satellites acquired this image of the iceberg as it continued drifting northward, breaking up into several smaller pieces.

Copernicus open data plays a key role in tracking the movement of icebergs in the ocean and in monitoring remote environments, including Antarctica. Its high temporal resolution allows for the consistent tracking of sea ice and large ice masses approaching coasts.