The Journey of Iceberg A23a: A Threat to South Georgia’s Wildlife

The world’s largest iceberg, A23a, is slowly making its way towards South Georgia, potentially threatening local wildlife. Covering an area of 1,1 million acres, it is approximately 75 times larger than Manhattan and weighs around one trillion tonnes. The iceberg stands over 1,300 feet above the water, with its sides regularly shedding chunks.

A23a originated from Antarctica’s Filchner-Ronne Ice Shelf in 1986 and initially drifted into the Weddell Sea, where it became grounded until 2020. After refloating, it took three years to reach the Antarctic Peninsula and entered the Antarctic Circumpolar Current in April 2024, which was expected to carry it northeast into warmer Atlantic waters.

However, the iceberg became stuck in the South Orkney Islands for much of 2024, likely caught in a Taylor Column, a rotating current. It finally broke free late last year and is now drifting towards South Georgia, approximately 180 miles away.

When it eventually breaks apart, A23a could pose risks to the limited vessel traffic in the area, mainly fishing boats, and may obstruct the rugged beaches of South Georgia, which are home to King penguins and seals. The last major iceberg to reach the island broke up in 2023, complicating navigation for commercial vessels.

Fishing boats must navigate through a shifting landscape of large ice blocks to access their fishing grounds. Mark Belchier, director of fisheries and environment for South Georgia, noted that any impact on wildlife from beach obstructions would likely be “highly localized and transient.”