Giant Iceberg A-81 Drifts Toward South Georgia Island

Some icebergs in Antarctica stay close to home for many years. They may run aground near the ice shelves they came from, or they may travel partway around the continent. One large iceberg, called A-81, is now making a long journey of its own.

Iceberg A-81 broke away from the Brunt Ice Shelf in January 2023. It covers roughly 1,550 square kilometers (600 square miles), which is a very large area. After it broke free, the iceberg headed north out of the Weddell Sea, along a route that many icebergs in the region have taken.

The Weddell Gyre, a large current that flows clockwise, carried Iceberg A-81 along the coast. The iceberg spent more than three years in the Weddell Sea before it moved on. By May 2026, it had reached the tip of the Antarctic Peninsula.

From there, Iceberg A-81 moved north into the Scotia Sea. By late October 2026, it was approaching South Georgia in the South Atlantic Ocean. South Georgia lies 2,300 kilometers (1,400 miles) north-northwest of the Brunt Ice Shelf.

The MODIS instrument on NASA's Terra satellite captured an image of the iceberg on October 20. The picture shows the iceberg as it neared the island. Jan Lieser of Australia's Bureau of Meteorology and Christopher Shuman of the University of Maryland (retired) made these observations, according to NASA.

Iceberg A-81's progress slowed noticeably in the days before October 20. The iceberg appeared to bump along the edge of South Georgia's underwater shelf, which is the gently sloping seabed that extends out from the island. Icebergs can run aground when they reach shallow water like this.

Iceberg A-81 is not the first to reach this area. In 2025, Iceberg A-23A ran aground on South Georgia's shelf and later broke apart. Another iceberg from the same ice shelf, Iceberg A-83, was calved from the Halloween Crack in 2024. It remains intact and is trailing A-81 northward.

The Brunt Ice Shelf is also home to the British Antarctic Survey's Halley Research Station, which has operated since the 1950s. Icebergs like A-81 come from the same ice shelf that supports this research station.