A large chunk of ice has broken off the Erebus Glacier Tongue, near McMurdo Base in Antarctica.
The process, known as calving, happens around every 30 years at the glacier, and the last time was in 1990.
The tongue sticks out to sea at the base of Mt Erebus and was estimated at 16 kilometres long before the chunk broke off.
Scientists at the base woke up this morning to see the iceberg, estimated at 3km long, drifting offshore.
Captain Scott himself noted that 4km broke off the tongue in a gale in March 1911, and Gerry Holdsworth estimated it broke off again in the 1940s.
The iceberg, which could contain around 15 million tonnes of ice, is expected to drift to the other side of McMurdo Sound.