What is the term for a crack in a glacier's surface?

What is the term for a crack in a glacier's surface? The answer is a crevasse. A crevasse is a deep fracture formed when flowing glacier ice is pulled, stretched, or sheared. Although glacier ice looks solid and rigid, it behaves like a slow-moving substance; differences in speed across the ice create enough stress to split the surface.

Crevasses are especially common where a glacier steepens, bends, widens, or flows over uneven ground. They can run across the glacier, along its length, or radiate near the edges. Some are only a few metres deep, while others can extend tens of metres into the ice. Snow can form a bridge over an opening, making a crevasse difficult to see and dangerous for climbers.

A moulin is different: it is a vertical shaft or channel that carries meltwater downward. A serac is a tower or block of fractured glacier ice, often found in an icefall. Bergschrund refers to a large crevasse separating moving glacier ice from stagnant ice or the mountain wall near a glacier's head.