Glaciology

Glaciology is the study of ice on land, and more broadly of ice in nature: how snow turns into glacier ice, how ice flows, how glaciers erode and deposit, and how ice sheets respond to climate. Glacial ice covers about 10 percent of Earth’s land today, including the ice sheets of Greenland and Antarctica, and glaciers and ice caps store about 69 percent of the world’s fresh water. If all land ice melted, sea level would rise by about 70 meters.

Glaciers move by deforming under their own weight and, where their base is wet, by sliding over their bed. As they move they pluck and grind the rock beneath, carving cirques, U-shaped valleys and fjords, and when they retreat they leave moraines, drumlins and erratic boulders. Much of northern Europe and North America is a landscape shaped by the ice of the last glacial period.

Start with Snowball Earth, the hypothesis that ice once covered nearly the whole planet, then Blood Falls, the red outflow of an Antarctic glacier, and Greenland’s nine-day seismic mystery.