Vast Antarctic iceberg set to calve

SEATTLE: A Delaware-sized iceberg is very close to splitting off from one of the largest ice shelves in Antarctica, scientists say, after a fast-growing crack stretched to within 13km of the open ocean this week.

Last month, aerial observations showed the crack had shifted toward the edge of the ice sheet and the open ocean, leading scientists to estimate that an iceberg more than 300 000 times the size of the one that sunk the Titanic could calve soon. The formation of the iceberg fits within a broader trend of shrinking ice shelves in the region, which scientists believe is linked to global warming.

The crack has grown an additional 17km in just the last week, according to observations released by Project Midas, a European research group which has been monitoring the region, making the iceberg’s separation imminent.

“I would expect it to occur quite rapidly, within days or weeks,” Dan McGrath, a scientist with the US Geological Survey said.

The 5 000km² chunk of ice has nearly completely broken off the Larsen C ice shelf, the fourth-largest in Antarctica. When it does, it will shrink Larsen C by about 10% and leave it with the smallest area ever recorded.

Scientists from Project Midas warned in 2015 that the loss of such a large mass of ice would create a “significant risk” of the shelf as a whole becoming unstable and breaking up, although McGrath cautioned that the larger outcome is not guaranteed.