1 00:00:01,050 --> 00:00:05,050 Generally speaking, as the climate 2 00:00:05,050 --> 00:00:09,050 warms, ice around the planet melts. But how fast it melts and 3 00:00:09,050 --> 00:00:13,050 where it melts is complicated by factors like how the 4 00:00:13,050 --> 00:00:17,050 climate’s changing and local weather patterns. 5 00:00:17,050 --> 00:00:21,050 Here at NASA, we use satellites, airplanes and research ships to take a closer 6 00:00:21,050 --> 00:00:25,050 look at the regional causes of melting and what’s driving them. 7 00:00:25,050 --> 00:00:29,050 NASA’s mission Ocean Melting Greenland, or OMG for short, is 8 00:00:29,050 --> 00:00:33,050 designed to figure out how much of Greenland’s ice loss is being caused 9 00:00:33,050 --> 00:00:37,050 by the oceans. 10 00:00:37,050 --> 00:00:41,050 Sometimes the oceans affected Greenland’s ice in surprising ways. 11 00:00:41,050 --> 00:00:45,050 This year, we figured out for the first time in almost 20 years, 12 00:00:45,050 --> 00:00:49,050 Greenland’s biggest glacier, Jakobshavn, stopped retreating 13 00:00:49,050 --> 00:00:53,050 and got thicker. The big question: Why? 14 00:00:53,050 --> 00:00:57,050 After looking at dozens of potential causes, 15 00:00:57,050 --> 00:01:01,050 we figured out that Jakobshavn’s slowdown was caused by 16 00:01:01,050 --> 00:01:05,050 cold water that flowed in from offshore. 17 00:01:05,050 --> 00:01:09,050 Where Jakboshavn meets the ocean, it sits in water that’s almost 18 00:01:09,050 --> 00:01:13,050 2,400 feet deep — that’s like eight football fields — 19 00:01:13,050 --> 00:01:17,050 and this water can affect the glacier very far inland. 20 00:01:17,050 --> 00:01:21,050 21 00:01:21,050 --> 00:01:25,050 Water in Disko Bay, shown here, flows into the canyon, 22 00:01:25,050 --> 00:01:29,050 or fjord that holds Jakobshavn, sometimes the 23 00:01:29,050 --> 00:01:33,050 water is warm, speeding up the melt of the glacier, and sometimes, 24 00:01:33,050 --> 00:01:37,050 it slows it down. In 2016, the water in Disko Bay 25 00:01:37,050 --> 00:01:41,050 got cold, reaching temperatures that were lower than at any time 26 00:01:41,050 --> 00:01:45,050 since the late 1980s. 27 00:01:45,050 --> 00:01:49,050 Natural cycles cool and then warm the 28 00:01:49,050 --> 00:01:53,050 far north Atlantic Ocean about once every 20 years. This cold water 29 00:01:53,050 --> 00:01:57,050 from 2016 arrived just as the Atlantic was shifting to its 30 00:01:57,050 --> 00:02:01,000 next cold period. 31 00:02:01,000 --> 00:02:05,050 Watch as the deep water temperatures warm up slowly 32 00:02:05,050 --> 00:02:09,050 through the years, until 2016, then get cold again. 33 00:02:09,050 --> 00:02:13,050 These waters are brought into Disko Bay by the currents of the North Atlantic, 34 00:02:13,050 --> 00:02:17,050 which flow around the southern tip of Greenland, carrying water 35 00:02:17,050 --> 00:02:21,050 northward up its west coast. 36 00:02:21,050 --> 00:02:25,050 37 00:02:25,050 --> 00:02:29,050 The cold water in Disko Bay caused a dramatic change 38 00:02:29,050 --> 00:02:33,050 in Jakobshavn, making it grow taller by 100 feet, 39 00:02:33,050 --> 00:02:37,050 or 30 meters, between 2016 and 2017. 40 00:02:37,050 --> 00:02:41,050 41 00:02:41,050 --> 00:02:45,050 What does this mean for Greenland? It means that the oceans play a key role in 42 00:02:45,050 --> 00:02:49,050 Greenland’s melt, and we have to watch the water just as closely as the ice 43 00:02:49,050 --> 00:02:53,050 if we want to know what the future holds. Here at NASA, 44 00:02:53,050 --> 00:02:57,050 we’re hard at work in the field, and the lab, to better understand 45 00:02:57,050 --> 00:03:01,050 how the ocean affects Greenland’s melting and how that will continue 46 00:03:01,050 --> 00:03:05,050 to change with the climate. 47 00:03:05,050 --> 00:03:09,583 NASA