One of the world's largest icebergs, named A23a, is now drifting beyond Antarctic waters after being grounded for more than three decades, as reported by the British Antarctic Survey. Originally breaking away from the Antarctic's Filchner Ice Shelf in 1986, the iceberg had been immobilized on the ocean floor in the Weddell Sea for many years. Approximately three times the size of New York City and over twice the size of Greater London, measuring around 4,000 square kilometers (1,500 square miles), the iceberg is now on the move. According to Andrew Fleming, a remote sensing expert from the British Antarctic Survey, the iceberg has been drifting for the past year and is currently accelerating past the northern tip of the Antarctic Peninsula, aided by wind and ocean currents.

Fleming noted that inquiries into possible changes in shelf water temperatures as a trigger yielded no conclusive evidence, with the consensus being that the iceberg's movement was simply a matter of time. Having been grounded since 1986, the iceberg eventually decreased in size sufficiently to lose its grip and start moving. Fleming first observed movement from the iceberg in 2020, and now, according to the British Antarctic Survey, it has become ungrounded and is making its way along ocean currents toward sub-Antarctic South Georgia.