Iceberg A-23A ranks among the giants known to have broken, or “calved,” from Antarctica. Though several other icebergs in the satellite era have been larger, A-23A was remarkable for its longevity. After spending its early days in the Weddell Sea, its journey came to an end in the South Atlantic Ocean, months shy of its 40th birthday.
These images show the iceberg at the start and end of its lifespan. The MSS (Multispectral Scanner System) on Landsat 5 captured the top image on November 10, 1986, shortly after Iceberg A-23 broke from the Filchner Ice Shelf. (The main section was later renamed A-23A after a smaller piece split off.) It is pictured here with several other major icebergs from the same calving event. A-23A outlived all of them.
The second image, captured by the VIIRS (Visible Infrared Imaging Radiometer Suite) on the NOAA-21 satellite on April 3, 2026, shows what remained of the iceberg at the end of its journey. By this point, the ice had drifted into warmer waters north of South Georgia and the South Sandwich Islands—more than 2,300 kilometers (2,000 miles) north of where the iceberg first calved.
Drifting Toward Disintegration
Iceberg A-23A’s final months brought abundant drift, melt, and breakage. It exited the U.S. National Ice Center’s area of analysis during the week of February 6, 2026, and was transferred to the jurisdiction of the Argentinian Meteorological Service as it drifted into maritime traffic lanes, according to the center’s ice analysts.
Jan Lieser of Australia’s Bureau of M …