ST. PETERSBURG, April 21. /TASS/. The A23a iceberg, which until last year was the largest in the world, has completely broken apart while drifting in the Southern Ocean, the press service of the Arctic and Antarctic Research Institute (AARI) reported.
"The world’s biggest iceberg, A23a, which has been tracked by the Arctic and Antarctic Research Institute scientists for the last 40 years, is no more. The frozen giant has split into small fragments, losing 99% of its original area over the entire period of its existence," the press service said.
The A23a iceberg broke off from the outer edge of the Filchner-Ronne ice shelf in Antarctica in 1986. Originally, it covered an area of 4,170 square kilometers (1,610 square miles), nearly twice the size of St. Petersburg. After remaining grounded in the shallow waters of the Weddell Sea for more than 30 years, it started drifting along the shore of Antarctica, and by November 2023 had been carried into open water.
At the beginning of 2025, the iceberg neared the island of South Georgia and grounded 80 kilometers (50 miles) from it, remaining there from January to May 2025. Then it continued drifting near the island, passing it from the eastern side. At the end of August, 2025, three big fragments, with an area of 60-300 square kilometers (23-116 square miles), detached from the iceberg. It lost its status as the world’s biggest iceberg at that time - shrinking to about 30% of its original size.
"Last year, the A23a iceberg was considered to be the world’s largest one, however, in September that status changed. In January, the iceberg’s area was about 1,300 square kilometers (502 square miles). At present, it covers an area of less than 50 square kilometers (19 square miles). Currently, the A23a iceberg is drifting in open water and crumbling apart. Over the last three months, it has traveled a distance of 1,000 kilometers (621 miles) and crossed the borders of the South Atlantic Ocean and the Atlantic Ocean. It is located near the latitude of 49° S," the press service reported, citing chief specialist of the AARI’s Ice and Hydrometeorological Information Center Polina Soloshchuk.