Page 382 - Laboratory Manual in Physical Geology
P. 382

5.   On the right-hand side of the graph on page 349, complete the topographic profile for line  A–B   across the Harvard Glacier
              ( FIGURE  13.10   ).

                 a.   Label the part of the profile that is the top surface of the glacier.


                 b.   Using a dashed line, draw where you think the rock bottom of the valley is located under the Harvard Glacier. (Your
                 drawing may extend slightly below the figure.)

                 c.   Based on the profile that you just constructed, what is the maximum thickness of Harvard Glacier along line  A–B?









           B.     Refer back to  FIGURE  13.10 , a portion of the Anchorage (B-2), Alaska, quadrangle, for the following questions. In the



            southwestern corner, note the Harvard Arm of Prince William Sound. The famous  Exxon Valdez  oil spill occurred just south
            of this area (it did not affect Harvard Arm).

                1.   Lateral and medial moraines in/on the ablation zone of Harvard Glacier are indicated by the stippled (finely dotted)
              pattern on parts of the glacier. If a hiker found gold in rock fragments on the glacier at location  C,  then would you look for
              gold near location  X, Y,  or  Z?  Explain your reasoning.










               2.   Notice the crevasses (blue line segments) within a mile of Harvard Glacier’s terminus. What specific kind of crevasses are
              they, and why do you think they formed only on this part of the glacier?














           C.   Refer back to the Yosemite Falls, California quadrangle (  FIGURE  13.11 ) and locate the small steep-sided valley upstream from

            Snow Creek Falls (about 1.5 km northeast of line  G–L ). Such valleys are common on the sides of valleys carved by valley


            glaciers. What is the name of this kind of valley ( FIGURE  13.4 ), and how did it form?





           D.       REFLECT & DISCUSS    Compare the topographic map and satellite image of Harvard Glacier. Does Harvard Glacier have
            a positive mass balance or a negative mass balance? Explain your reasoning.















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