1 00:00:00,000 --> 00:00:02,370 Scientists using ice-penetrating 2 00:00:02,390 --> 00:00:03,930 radar data from NASA 3 00:00:03,950 --> 00:00:07,520 have built the first-ever comprehensive 3-D map 4 00:00:07,540 --> 00:00:10,460 of the layers deep inside the Greenland Ice Sheet. 5 00:00:10,480 --> 00:00:12,910 This highlights how the ice sheet evolved 6 00:00:12,930 --> 00:00:14,470 and how it's flowing today. 7 00:00:14,490 --> 00:00:15,028