A huge iceberg, almost the size of Greater London, has broken off the 150m thick Brunt Ice Shelf in the Antarctic after cracks extended across the entire ice shelf.
The crack known as Chasm-1 had until 2012 been dormant for about 35 years, but over the last decade developed naturally as the ice shelf flowed towards the sea at a rate of about 2km per year.
It is not believed to be due to climate change, as atmospheric temperatures above the Brunt Ice Shelf are consistently sub-zero, and no warmer ocean water penetrates into the cavity under the shelf. The iceberg calved when Chasm-1 extended completely through the 150-metre thick ice shelf.
