The world's second largest ice sheet seems uniform and motionless from above. But years of satellite measurements compressed into a few seconds illustrate just how fluid Greenland's ice really is. Several space agencies, including NASA, have closely monitored the ice sheet to understand how its dynamics might be influenced by changes to Earth's climate and how such changes could affect sea level rise. With the help of a remote sensing technique called radar interferometry, NASA scientists were able to create the first complete map that shows how Greenland's ice moves from the interior toward outlet glaciers on the coast. The speed and direction of the flows can be seen in the color-coded visualization, where areas shaded blue and purple represent the fastest ice, yellow and pink the slowest.