In a sign of the effect of global warming, scientists believe a massive ice shelf is due to break away from Antarctica’s Larsen C ice shelf within the next few months.
A slow-progressing rift suddenly grew by 18 kilometres (11 miles) at the end of December, leaving the finger-shaped chunk – 350 metres thick – connected along only a small fraction of its length. The rift has also widened, from less than 50 metres (160 feet) in 2011 to nearly 500 metres today.
By itself, the soon-to-be iceberg will not add to sea levels, the likely consequence of ice sheet disintegration that most worries scientists. The real danger is from inland glaciers, held in place by the floating, cliff-like ice shelves that straddle land and sea.
The fragile West Antarctic ice sheet – where Larsen C is located – holds enough frozen water to raise global oceans by at least four metres (13 feet).