Learn about glaciers on a tour of Greenland's Helheim Glacier in this video from NOVA Digital. Helheim is a massive glacier that is flowing toward the ocean at a rate of about 3 feet per hour. The glacier presents a colorful landscape of whites, blues, and grays and has striking features, including pinnacles of ice, huge crevasses, and rivers of meltwater. At the terminus, where the glacier meets the ocean, icebergs break off and create a mixture of ice called a mélange. As the ice travels away from the glacier, it eventually melts. Meanwhile, snow falling on the Greenland ice sheet replenishes Helheim and thousands of other glaciers in Greenland.