Changes to glacier 'disturbing,' say alarmed scientists
                                
                                
                                    (Newser) -
                                    A colossal iceberg twice the size of Manhattan has broken away from the end of Greenland's Petermann glacier. Another, even bigger, iceberg  broke from the northerly glacier in 2010 , and scientists had been keeping an eye on a crack near the glacier's tip for years, reports  AP . "...