The accompanying diagram shows the results of a classic experiment used to determine how glacial ice

The accompanying diagram shows the results of a classic
experiment used to determine how glacial ice moves in a mountain valley. The
experiment occurred over an 8-year span. Refer to the diagram and answer the
following:

a. What was the average yearly rate at which ice in the center
of the glacier advanced?

b. About how fast was the center of the glacier advancing
per day?

c. Calculate the average rate at which ice along the sides
of the glacier moved forward.

d. Why was the rate at the center different than the rate
along the sides?