Glaciers and ice sheets move in unique and hard to map patterns as observed by satellite images that help map the speed of flowing ice in Greenland, Antarctica and mountain ranges around the world. Twila Moon, a graduate of the PCC, talks about using this evidence to help map out glaciers in Greenland. With the new database, she can study the movements of more than 240 glaciers, which comprise nearly all of the outlets from the ice sheet.