The bottom or downward tip of a crevasse marks the _________.
A) boundary between parts of the glacier moving by basal sliding and crevassal slip
B) boundary between the basal sliding and external flowage zones
C) top of the internal deformation and flowage zone, and the base of the brittle zone of fracture
D) bottom of the basal sliding zone

Question

Quizplus · Accepted Answer

Crevasses form in the brittle zone of a glacier, where tensional forces cause the ice to fracture. The bottom or downward tip of a crevasse marks the transition from this brittle zone to the underlying zone where ice deforms plastically and flows, known as the internal deformation and flowage zone.

The Bottom or Downward Tip of a Crevasse Marks the _________