Monday 12 June 2017 11.00 BST
Very soon, a large portion of an ice shelf in Antarctica will break off and collapse into the ocean. The name of the ice shelf is Larsen C; it is a major extension from of the West Antarctic ice sheet, and its health has implications for other ice in the region, and sea levels globally.
How do we know a portion is going to collapse? Well, scientists have been watching a major rift (crack) that has grown in the past few years, carving out a section of floating ice nearly the size of Delaware. The speed of the crack has increased dramatically in the past few months, and it is nearly cracked through.
Project Midas provides frequent updates on the Larsen C shelf. You can read a summary there, which reports:
In the largest jump since January, the rift in the Larsen C Ice Shelf has grown an additional 17 km (11 miles) between May 25 and May 31 2017. This has moved the rift tip to within 13 km (8 miles) of breaking all the way through to the ice front, producing one of the largest ever recorded icebergs. The rift tip appears also to have turned significantly towards the ice front, indicating that the time of calving is probably very close.
The rift has now fully breached the zone of soft ‘suture’ ice originating at the Cole Peninsula and there appears to be very little to prevent the iceberg from breaking away completely.
When it calves, the Larsen C Ice Shelf will lose more than 10% 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. We have previously shown that the new configuration will be less stable than it was prior to the rift, and that Larsen C may eventually follow the example of its neighbor Larsen B, which disintegrated in 2002 following a similar rift-induced calving event.