Astronomy/Geology 1070: Earth: Its Physical Environment

University of Wyoming

Fifth Homework Assignment, Due October 1, 2009
10 points

To receive credit, your completed assignment must be submitted to me by the beginning of class on Thursday, October 1.

Do one, and only one, of the following:

1. Volcano shapes.

Different types of volcanoes have distinctive shapes. Stratovolcanoes have have concave profiles that steepen toward the peak, shield volcanoes have convex profiles, cinder cones are straight-sided, and caldera volcanoes are enormous holes in the ground. Explain how and in what contexts these different shapes are created.

2. Volcano locations.

In general, stratovolcanoes form near subduction zones and shield volcanoes and cinder cones form in rift zones. Why is this? What about the structure of these locations and the processes occurring there comtrol the creation of these two types of volcano?

3. Oil reserves.

It is often claimed that, since oil companies continue to find more oil-containing deposits, there is no forseeable prospect of an oil supply shortfall. What is wrong with this logic? What factors other than the frequency of new oil strikes affect the sufficiency of the oil supply?

It may be true that there will be no oil supply shortfall in the future; that’s not the point here. The point is that the lone fact that new oil discoveries are occurring does not guarantee that a shortfall will not occur. Explain.

Take your choice of these tasks. Do not submit answers to more than one of them. Just choose one, and submit it. Your answer should thoroughly address all points of the question. An adequate answer will be several paragraphs long.

Warning: Do not turn in paper that has ragged edges! If you write your work in a spiral-bound notebook, trim the edge before submitting it. Papers with ragged edges will be returned unmarked.