Iceberg breaks off from Greenland's Petermann Glacier
19 July 2012 Last updated at 02:57 BST
The Petermann Glacier in northern Greenland has calved an iceberg twice the size of Manhattan, scientists say.
Images from a Nasa satellite show the island breaking off a tongue of ice that extends at the end of the glacier.
In 2010 an ice island measuring 250 square km (100 square miles) broke off the same glacier.