Basal Sliding of a Glacier Occurs Because of ____________

Multiple Choice

Basal sliding of a glacier occurs because of ____________.

A) the steepness of the ground that it flows over
B) the lubricating effects of nonphotosynthesizing algae found beneath some glaciers
C) seeps of methane and other organic gasses or liquids from the underlying sediment or ground
D) water or sediment slurry beneath a glacier