GL101 Lecture Notes - Lecture 18: Paternoster, Basal Sliding, Loess
Document Summary
The central position of a valley glacier moves faster than the sides, and the surface moves faster than the base. Basal sliding the sliding of the glacier as a single body over the underlying rock. The ice nearer the top apparently rides along passively on the plastically moving ice closer to the base. In the rigid zone, grains of ice do not move relative to their neighbours. Within the plastic zone, the ice grain on the upper part slides farther than the underlying grain. In the rigid zone, on the other hand, the ice grains are locked together and move in unison. Hence, within the rigid zone, the distance moved by grains in the lower part of the zone is similar to that moved by grains in the upper part of the zone (they move together). Where the glacier passes over a steep part of the valley floor, it moves faster.
