
Antarctic Megaberg A23a Nears Complete Breakup in Warmer Atlantic
A Copernicus Sentinel-2 image shows A23a, once the world’s largest iceberg that calved from the Filchner-Ronne Ice Shelf in 1986, continuing to disintegrate as it drifts into warmer South Atlantic waters. By December 2025 it lies about 150 km northwest of South Georgia, has shed roughly three-quarters of its surface to about 1,000 sq km, and meltwater ponds indicate rapid breakup as it heads toward further disintegration in warmer seas.













