1 00:00:00,030 --> 00:00:02,190 2 00:00:02,210 --> 00:00:07,130 July 16th, 2012 - the Petermann Glacier in northwest Greenland 3 00:00:07,150 --> 00:00:12,470 lost a massive iceberg, for the second time in three years. 4 00:00:12,490 --> 00:00:16,660 As the ice floating in the fjord broke up, the ice island was carried by the current 5 00:00:16,680 --> 00:00:21,550 down the glacier's outlet channel and toward the Nares Strait. 6 00:00:21,570 --> 00:00:25,220 Known as Petermann Ice Island 2012, 7 00:00:25,240 --> 00:00:30,400 it is bigger than Manhattan island - and floating at one kilometer per day. 8 00:00:30,420 --> 00:00:35,980 NASA's Aqua and Terra satellites made multiple passes each day over the polar regions, 9 00:00:36,000 --> 00:00:41,470 allowing scientists to track the ice island - whenever clouds didn't block the view. 10 00:00:41,490 --> 00:00:46,060 Scientists have been watching this crack develop since 2001. 11 00:00:46,080 --> 00:00:50,200 Ocean temperatures are one factor determining when glaciers will calve an iceberg. 12 00:00:50,220 --> 00:00:54,330 Warmer water destabilizes the ice. 13 00:00:54,350 --> 00:00:59,990 14 00:01:00,010 --> 00:01:06,540 After two months at sea, Petermann Ice Island 2012 had begun to fragment as it floated down the strait. 15 00:01:06,560 --> 00:01:10,600 16 00:01:10,620 --> 00:01:19,993