Question

At depths of greater than 60 m, ice moves by plastic deformation. What causes this transition from brittle to ductile behavior? A. An increase in temperature causes the glacier to melt and slide. B. An increase in pressure increases friction and melts the ice. C. An increase in the pressure allows for only minute deformation. D. A decrease in the amount of trapped sediments allows more flow

Answer 1

Answer: An increase in the pressure allows for only minute deformation.

Explanation: A glacier is a large body of ice which flows under its own mass, usually downhill. They are formed where the accumulation of snow exceeds its melting and sublimation over many years. The pressure on ice deeper than 50 m causes plastic flow this is because at the molecular level, ice consists of stacked layers of molecules with relatively weak bonds between layers. When the stress on the layer above exceeds the inter-layer binding strength, it moves faster than the layer below.