ANTARCTICA • A long-growing crack in the Larsen C ice shelf, one of Antarctica's largest floating platforms of ice, appears to be nearing its endgame.
Researchers with Project Midas, working out of Swansea University and Aberystwyth University in Wales and studying the shelf by satellites and through other techniques, have released a new update showing that the crack grew a stunning 18km in the space of just one week between May 25 and May 31.
It now has just 13km to go before an iceberg roughly seven times the size of Singapore breaks free into the Southern Ocean.
"There appears to be very little to prevent the iceberg from breaking away completely," the researchers write. Elsewhere in their post, they note that the crack has now curved towards the front of the ice shelf and the ocean, meaning that the time when a major break could occur "is probably very close".
The researchers estimate that the section of ice set to break off could be around 5,180 sq km in area.
"When it calves, the Larsen C Ice Shelf will lose more than 10 per cent of its area to leave the ice front at its most retreated position ever recorded. This event will fundamentally change the landscape of the Antarctic Peninsula," wrote the Project Midas team.
Its neighbour, Larsen B, disintegrated in 2002.
The prospect of an enormous iceberg afloat around Antarctica could draw further attention to the threat of climate change at a time when US President Donald Trump is considering exiting the Paris agreement to reduce greenhouse gas emissions.
An ice shelf is the floating extension of a glacier that itself grows from the land out into the ocean. The loss of a large iceberg from Larsen C would not raise the sea level, since the ice is already afloat.