An iceberg twice the size of Manhattan has broken away from the Petermann Glacier in northern Greenland, raising concerns about North Atlantic shipping lanes and oil platforms.
This is the second time in less than two years that the Petermann Glacier has calved a monstrous ice island. In 2010, it unleashed another massive ice chunk into the sea.
"At this time of year, we're always watching the Petermann Glacier," Wohlleben said, because it can spawn big icebergs that invade North Atlantic shipping lanes or imperil oil platforms in the Grand Banks off Newfoundland. A large piece of the 2010 iceberg did just that, but caused no damage, she said by telephone.
NASA images showed the iceberg calving -- breaking off from a floating river of ice called an ice tongue, part of the land-anchored Petermann Glacier -- and moving downstream along a fjord on Greenland's northwest coast. A rift in the ice had been identified in 2001, but on Monday a crack was evident.
On Tuesday, the satellite spied a bigger gap between the glacier and the iceberg, and the ice chunks further downstream were breaking up, NASA said.