World’s largest iceberg having a meltdown

By Dean Murray

The world's largest iceberg is losing its edge - and now resembles a 'Starry Night' in the ocean.

Researchers tracking A-23A say the large mass is being chipped away by natural elements and is rapidly shrinking.

Though still the largest iceberg currently at sea, its surface area has declined considerably in just two months.

According to iceberg data from the U.S. National Ice Center (USNIC), A-23A lost more than 360 km² (140 square miles) between 6 March and 3 May—an area roughly twice the size of Washington, D.C.

At its largest, the freezing mass covered an area of approximately 4,000 km² (about 1,550 square miles)—more than twice the size of Greater London and about three times the size of New York City.

NASA Earth Observatory (NASA EO) said: "Thousands of iceberg pieces litter the ocean surface near the main berg, creating a scene reminiscent of a dark starry night. Though these fragments appear small in the image, many measure at least a kilometre across and would pose a risk to ships."

One fragment, A-23C, was large enough to be named by USNIC after it broke from A-23A’s southern side in mid-April.

A-23A has been stuck for several months in the shallow waters less than 100 km (60 miles) off the island of South Georgia. Waves and other seasonal weather effects are chipping away at its sides and shrinking its visible surface area.

NASA Earth Observatory said: "The berg’s underside is most likely lodged on a shallow underwater shelf around South Georgia, known in the past to have snagged several Antarctic icebergs on their northward drift into warmer South Atlantic waters. Satellite images show that the iceberg has remained at a standstill since at least early March 2025."

The next largest iceberg is A-76A, measuring about 135–170 km long and 25 km wide, roughly the size of Cornwall or twice the size of Greater London. At its largest, A-76A measured approximately 3,500 km² (about 1,350 square miles) soon after it broke off from the main A-76 iceberg in May 2021. It has been drifting north through the South Atlantic since calving from the Filchner–Ronne Ice Shelf in May 2021.