Glacial Geology

Homework: Glacier Mass Balance

 

Objectives:

Become familiar with the environments of glacial systems

Develop problem solving skills

Solve these problems: (33 1/3 points each)

1. For Gulkana Glacier estimate the net glacier gain/loss from 1966 to 1995 from a hydrological analysis. Compare this with published mass balance values and discuss any differences. Estimate the mean ELA and ELA for a specific net blance of 0 (e.g. equiblium). Discuss the significance of the difference. For data sets see Gulkana Glacier, Alaska Home Page, USGS

2. Arendt et al (2002) published a paper in Science -- Arendt et al. 297 (5580): 382 . This work rasises several interesting questions. How does the mass balance you found in problem 1 compare with the estimate they provide? (see Science -- Arendt et al. 297 (5580): 382 Data... ). Explain any differences.

Science requires a password, but if you log in from campus, you can access this paper.

3. For (pick one mountain range: Southern Alps of New Zealand, Canadian Rockies, Coastal Range of Alaska) estimate the present ELA surface. (Be sure N>25). Discuss why it has the shape determined.

4. BONUS (15 pts) - Estimate the ELA when the Pinedale Glacier stood at the end of Fremont Lake at Last Glacial Maximum( ~20,000 yr BP), when the Inner Titcomb Lake Moraine formed during Younger Dryas Time (10,000 yr BP) and the present ELA. Suggest and discuss a relationship between ELA drop and position of the glacier margin from the mountain chain divide.

5. Bonus (5 pts) - The Sept 15 2000 issue of the journal Science has an image of Antarctica on the cover. Study that image carefully and identify a major problem with it. The image is on-line.

Resources:

Chap 2 Benn and Evens

Air Photos and maps in Room 628

  • http://ak.water.usgs.gov/glaciology/gulkana/photos/oblique_aerials/67.htm

    • Tools you may want in your tool kit:

    Evaluation:

    For these questions, you should present a logical response in an effective manner. Thus, evaluation will be based on both the content and its presentation.

    1/2 of total. Technical assessment (e.g. question posed is the one addressed, no unnecessary information presented, answer is a logical argument, is the answer "correct"?).

    1/2 of total. Style (e.g. arguments linked together, correct grammar, correct spelling).

    e-mail all text and supporting plots to me by next Monday 7:00 am.