Nightly News | July 18, 2012
>>> a warming atlantic ocean has taken its toll again on one of greenland's giant glaciers. a piece twice the size of the island of manhattan has broken free. scientists have been watching a crack in the glacier for years. nasa took a satellite photo as it started to break off days ago. two years ago a piece twice the size of this one broke off. scientists will be watching carefully again to see if this is the end of it for now.