Author Question: Explain why glaciers are much more effective agents of erosion than streams, even though glaciers ... (Read 54 times)

newbem · **on:** Jul 16, 2018

Explain why glaciers are much more effective agents of erosion than streams, even though glaciers move much slower than streams.

What will be an ideal response?

Question 2

What is the major difference between an intermittent stream that is dry part of the year and a stream that flows year-long, even when it has not rained or snowed for several weeks?

What will be an ideal response?

phuda · **Reply #1 on:** Jul 16, 2018

Answer to Question 1

The shear stress (force exerted by a moving object or fluid) is the critical factor when comparing the erosion by glaciers and streams. The shear stress increases with the increasing weight of the flowing material. Glaciers are many times thicker than the depth of water in streams, which means that the weight exerted at the bottom of a glacier is much greater than the weight exerted by water on a streambed. These differences mean that the shear stress exerted by flowing ice is much greater than that exerted by flowing water.

Answer to Question 2

The stream that flows year-long has a stream bed that is below the water table. It is fed by ground water year-round and by surface runoff after storms. The stream that is dry part of the year is not fed by ground water year-round.