An enormous 1,550-square-kilometre iceberg broke off from Antarctica’s Brunt Ice Shelf on Sunday during a spring tide, the British Antarctic Survey polar research organization announced on Tuesday. The massive ice formation is about the size of London and its surrounding suburbs. Unlike several similar iceberg events in recent years, researchers said they did not believe climate change was responsible for the gigantic iceberg. “This calving event has been expected and is part of the natural behaviour of the Brunt Ice Shelf. It is not linked to climate change,” said BAS glaciologist Dominic Hod…