Saturday, 6 May 2017

Huge 100-mile crack appears on one of Antarctica's largest ice shelves, sparking fear among scientists

Widening cracks in Larsen B, an ice shelf on the Antarctic peninsula, could be a warning sign that it's about to break away from the continent
Another branch has appeared in a huge crack on one of Antarctica's largest ice shelves, and scientists fear it's only a matter of time before a huge chunk - potentially containing up to 2,000 square miles 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 111 miles long - has been advancing in rapid bursts in recent years. Between the beginning of December and the middle of January alone, the crack lengthened by about 17 miles. And since 2011, it has grown by about 50 miles.
Over the past few months, scientists have noticed that the crack has stopped extending in length but has continued to widen at a rate of more than three feet per day. It's already more than 1,000 feet wide.
And now, scientists have noticed a worrying development: a new branch has split off from the main rift, about six miles below the tip of the original crack, and has splintered off in the direction of the ocean. The new branch is about nine miles long. Altogether, only about 12 miles of ice now 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 Universit and Aberystwyth University, observed the new crack in satellite images on May 1.

The biggest concern is not whether the chunk will break off - that seems to be inevitable at this point - but what will happen after it does. The break will sweep away about 10 per cent of the ice shelf's total area, and scientists have previously speculated that the shelf will become increasingly unstable after this point.

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