1. We may not have formally discussed the concept of feedback loops until late in the class, but we have actually discussed many processes that count as feedback loops over the course of the semester. LIST and DESCRIBE three different POSITIVE feedback loops from different units of this class. (9 points)2. Suppose there has just been a high-volume explosive eruption from a felsic volcano. Explain how the impacts of this eruption will affect all five parts of the Earth System. (10 points)3. Explain how the structure of silicate minerals ultimately affects how different types of tectonic plates form and interact. (10 points)4. Look at the above figure of tectonic plates. The arrows indicate direction of motion, the letter C indicates a continental plate, and the letter O indicates an oceanic plate. For each lettered plate boundary, determine what type of boundary it is. If it is a transform boundary, say whether it is right- or left-lateral. If it is a subduction zone, say which plate is the one subducting. (10 points)5. The figure above is a geologic cross section. Put each labeled feature in order from OLDEST to YOUNGEST. If you think any two things are the same age, say so, and explain in the next question. (8 points)6. Looking again at the figure above and the order you put things in for question 5, come up with a sequence of geological processes that could have produced those features in that order. (16 points)7. We have talked a lot about the role of water in this class. List FIVE different processes/systems in which water plays a role, and briefly describe what water does in each situation. (15 points)8. The list below is an example of a rock going through the rock cycle. For each step, say what specific type of rock it is (hint: be as specific with each rock type as we got in our lectures), and whether that type of rock is igneous, sedimentary, or metamorphic. (10 points)a. Rocks that started out flat get compressed and uplifted into a mountain range.b. Turns out that the compression is from subduction, and a new volcano forms within those mountains. It melts some of the rock from the previous step, then erupts it.c. A mountain stream on that volcano carves out and carries different sized chunks of the rock from the previous step (and a whole bunch of other rocks) down to the bottom of the mountain, where they collect and eventually stick together into a new rock.d. Over the next several hundred thousand years, rainwater breaks down the rock from the previous step into very tiny particles, which eventually stick together to form a new rock.e. Over time, the pressure of more material collecting above changes the structure of the rock in the previous step.Think about the many geologic hazards we’ve discussed in this class. Which one do you think is the MOST dangerous? Which one would you feel SAFEST living near? Give clear and specific reasons for both of your decisions. (Hint: it may be helpful to compare your choices to some of the other hazards that rank somewhere in the middle for you.) (12 points)
