Extended Data Fig. 4: Iceberg A76 mass estimation.

Weeks after our March 2021 annual pan-Antarctic coastline mapping, the Ronne Ice Shelf calved the 4320 km2 iceberg A76. By considering changes in area and mass that have occurred between each of our 24 consecutive mappings, we estimate that iceberg A76 took 1,002 Gt of ice from Ronne Ice Shelf.