Overview
- A23a has shrunk to roughly 180 square kilometres and researchers say the remaining pieces could vanish within weeks.
- Calved from the Filchner-Ronne Ice Shelf in 1986, the iceberg stayed grounded in the Weddell Sea for over 30 years before drifting again around 2020.
- Fragmentation accelerated in 2025, producing named pieces A23g, A23h and A23i as hydrofracturing from meltwater and warm-water erosion weakened the berg.
- China’s Fengyun-3D satellite measured the main body at about 506 square kilometres in January 2026, and the U.S. National Ice Center stops routine tracking below roughly 70 square kilometres.
- Researchers are using the breakup to study nutrient releases that can spur phytoplankton blooms and to refine understanding of how warming may destabilize Antarctic ice shelves.