A23a

Iceberg A23a was a large tabular iceberg which calved from the Filchner–Ronne Ice Shelf in 1986. It was stuck on the sea bed for many years but then started moving in 2020. As of January 2025, its area was about 3,500 square kilometres (1,400 sq mi), which made it the largest iceberg in the world. As of March 2025, it had run aground off South Georgia island. By July 2025, it had started drifting again. It later passed to the east and north of South Georgia, and in September 2025 it was observed to be breaking up in warmer waters. In March 2026, the largest remnant became small enough that formal monitoring ceased, and as of July 2026 the iceberg was thought to have either disintegrated completely or to be on the verge of doing so.