Greenland in the Arctic circle's gotten that bit smaller because dramatic fluctuations in the climate mean a huge iceberg's broken loose.

Scientists have been monitoring the crack close to the edge of the Petermann glacier for years and now they reckon the 46 sq mile iceberg – twice the size of New York's Manhatten island – might have important implications for the world's environment.

These are the pictures of the glacier from NASA's Aqua satellite show it moving off downstream along a fjord on Greenland'snorthwest coast. It's the second time in less than two years that a glacier's broken free, but apparently it's half the size of the last one that happened in 2010.

One of the first professors to notice the crack said the rate of change that Greenland's experiencing is 'dramatic' and 'disturbing although researchers still don't have any decisive data proving the breakaway is to do with global warming. Others say they're still trying to figure out just how big the implications are because the changes aren't as a result of just natural shearing away.