WASHINGTON • Another branch has appeared in a large crack on one of Antarctica's largest ice shelves, and scientists fear it is only a matter of time before a huge chunk - potentially holding up to 5,100 sq km of ice - breaks away.
If this happens, the ice shelf may become increasingly unstable and could even fall apart.
Scientists have been closely monitoring the Larsen C ice shelf, located on the east coast of the Antarctic peninsula, where a large rift in the ice - now about 178km long - has been advancing in rapid bursts in recent years.
Over the past few months, scientists have noticed a new branch has split off from the main rift. The new branch is about 14km long.
Altogether, only about 19km of ice stand in the way of the whole chunk splitting off into the sea.
Researchers from Project Midas, a UK-based Antarctic research project based at Swansea University and Aberystwyth University, said the biggest concern is what will happen when the chunk eventually breaks off. The break will sweep away about 10 per cent of the ice shelf's total area.
Larsen C "may eventually follow the example of its neighbour Larsen B, which disintegrated in 2002 following a similar rift-induced calving event", said Swansea University's Professor Adrian Luckman, a leader at Project Midas.
Ice shelves serve as a kind of stopper at the edges of glaciers, stabilising and containing all the ice behind them. When they break, they have the potential to unleash a flood of ice from the continent that can significantly contribute to rising sea levels.