World’s Largest Iceberg A23a Runs Aground Near South Georgia Island

The world’s largest iceberg, A23a, has run aground near South Georgia, a remote British overseas territory known for its diverse wildlife. Scientists are closely monitoring the situation to understand its impact on local ecosystems. While the iceberg may disrupt wildlife feeding routes, it could also enhance ocean productivity by releasing nutrients as it melts. A23a, which broke off from Antarctica in 1986, has been drifting for decades and finally became lodged on the continental shelf near South Georgia. Scientists remain uncertain whether it will remain in place or move again due to oceanic conditions.

Key Highlights

Iceberg A23a and Its Journey

• A23a is the world’s largest iceberg, approximately the size of Rhode Island and weighing nearly a trillion tonnes.
• It calved from Antarctica’s Filchner Ice Shelf in 1986 and remained stuck in the Weddell Sea for more than 30 years.
• In 2020, it broke free and drifted northward past the Antarctic Peninsula.
• It was trapped in a Taylor Column vortex for several months before continuing toward South Georgia.
• Satellite images from March 1, 2025, confirm that it has now run aground on the continental shelf, 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.