The iceberg spanned an area of 3,672 square kilometers (1,418 square miles) when measured in August 2024 – slightly smaller than Rhode Island and more than twice the size of London. It calved from the Filchner Ice Shelf in Antarctica in 1986 and then rested on the seabed in the Weddell Sea for more than 30 years.

The world’s largest and oldest iceberg, A23a, has come to a halt near South Georgia Island in the South Atlantic Ocean, according to the British Antarctic Survey.

A23a weighs nearly a trillion metric tons, making it the world’s largest active iceberg. It calved from Antarctica in 1986, making it the world’s oldest berg. And now, after drifting for half a decade, A23a has grounded itself about 56 miles (90 kilometers) south of South Georgia.