From above, Antarctica appears as a massive sheet of white. But if you were to zoom in, you would find that an ice sheet is a complex and dynamic system. In the Department of Earth, Atmospheric and Planetary Sciences (EAPS), graduate student Meghana Ranganathan studies what controls the speed of ice streams — narrow, fast-flowing sections of the glacier that funnel into the ocean. When they meet the ocean, losing ground support, they calve and break off into icebergs. This is the fastest route of ice mass loss in a…