This rare footage (4:41) has gone on record as the largest glacier calving event (the breaking off of ice at the end of the glacier) ever captured on film. On May 28, 2008, Adam LeWinter and Director Jeff Orlowski filmed a historic breakup at the Ilulissat Glacier in Western Greenland. The calving event lasted for 75 minutes and the glacier retreated a full mile across a calving face three miles wide. The height of the ice is about 3,000 feet, 300-400 feet above water and the rest below water.
If you would like to know more about glacier mass balance, see this article from AntarcticGlaciers.org