Once Unstoppable, Antarctica’s Megaberg Crumbles Apart

The colossal Antarctic iceberg A23a, once among the largest ever recorded, is nearing the end of its extraordinary journey nearly four decades after it first calved from Antarctica in 1986.

Originally weighing close to a trillion tonnes and stretching more than twice the size of Greater London, the megaberg remained stuck in the Weddell Sea for over 30 years before breaking free in 2020.

Since then, it has drifted along the infamous “iceberg alley” into the South Atlantic, at times threatening penguin and seal feeding grounds near South Georgia Island.

Now, exposed to warmer waters and powerful waves, A23a is rapidly disintegrating, shedding city-sized chunks as it “rots from underneath.”

Though scientists were surprised it survived this long, experts say its days are numbered, with the iceberg expected to vanish completely within weeks—an ominous sign of how rising ocean temperatures and climate change are accelerating the loss of polar ice.