The largest iceberg in the world, A23a, has become stuck near South Georgia, a remote British overseas territory famous for its rich wildlife. Scientists are keeping a close eye on the situation to assess its effects on local ecosystems. While the iceberg might interfere with wildlife feeding patterns, it could also boost ocean productivity by releasing nutrients as it melts. A23a, which broke away from Antarctica in 1986, has been drifting for many years and has finally settled on the continental shelf near South Georgia. Scientists are still unsure if it will stay in place or drift again due to changing ocean conditions.
Key Highlights
Iceberg A23a and Its Journey
A23a is the largest iceberg in the world, roughly the size of Rhode Island and weighing close to a trillion tonnes. It broke off from Antarctica’s Filchner Ice Shelf in 1986 and remained stuck in the Weddell Sea for over 30 years. In 2020, it finally broke free and started drifting northward past the Antarctic Peninsula. For several months, it was caught in a Taylor Column vortex before it continued its journey toward South Georgia. Satellite images taken on March 1, 2025, show that it has now run aground on the continental shelf, just 73 km from South Georgia.
Potential Impact on Wildlife
- South Georgia is home to millions of seals and penguins.
- Scientists fear A23a may block access to key feeding areas, forcing wildlife to travel longer distances and potentially reducing food supply for young animals.
- Seals, penguins, and seabirds could be affected by the obstruction of migration routes.
Potential Environmental Benefits
- Melting icebergs release essential micronutrients into the ocean.
- The mixing of ocean layers could boost phytoplankton growth, increasing food availability for marine species.
- This could enhance populations of local predators like seals and penguins.
Scientific Research Opportunities
- Scientists are studying how icebergs impact marine ecosystems and carbon capture in the ocean.
- Researchers are examining underwater geological changes, including possible seafloor scars and landslides caused by A23a’s grounding.
- The event provides insights into climate change effects on ice shelves and ocean circulation.
Possibility of Movement
- Canadian ice specialist Donavan Tremblay suggests that A23a may move again due to strong storms and ocean currents.
- A previous megaberg, A68a, also ran aground near South Georgia in 2020, later breaking apart and releasing 152 gigatonnes of fresh water into the ocean.
