Read 4.2 Plate Tectonics to better understand the following sections
1. Contrast relative plate motions at a) convergent plate boundaries, b) divergent plate boundaries, and c) transform plate boundaries.
2. Give a geographic location to illustrate each type of convergence: oceanic-continental, oceanic-oceanic, and continental-continental. (Also see fig. 4.10)
3. At which types of convergent plate boundaries is oceanic crust subducted? (Also see figs. 4.11, 4.15, and 4.17)
4. Give the name of the long transform plate boundary at the North American Plate's western edge. (Also see fig. 4.10)
4.4 Convergent Plate Boundaries
5. Which ocean contains most of the subduction zones? (Also see fig. 4.10)
6. Explain why the Pacific Ocean is decreasing in size, whereas the Atlantic and Indian Oceans are increasing in size.
7. Explain why the oldest seafloor is 170 million years old, despite Earth being 4.6 billion years old.
8. Explain the discovery of marine fossils at high elevations in the Andes Mountains.
9. Explain why volcanism occurs at oceanic-continental convergent plate boundaries. (See figs. 4.12 and 4.13)
10. Use the concept of exotic terranes to explain the formation of much of California, Oregon, and Washington. (Also see figs. 4.10 and 4.14)
11. List several magmatic arcs. (Also see fig. 4.16)
12. Explain why the distance between the trench and the volcanic chain is less where the suduction lithosphere is older.
13. Explain why continental lithosphere cannot subduct.
14. Explain the formation of the Himalayas, the Alps, and the Appalachians. (Also see fig. 4.17)
15. Which type of plate boundary formed the East African Rift Zone?
16. Which type of plate boundary forms a mid-oceanic ridge (MOR)?
17. Where is oceanic crust (new seafloor) formed?
18. Explain why the East Pacific Rise does not contain a central rift valley like the Mid-Atlantic Ridge. (Also see fig. 4.19)
19. Explain why a new sea, an incipient ocean like the Red Sea, might form in Africa.
20. Explain why transform faults at an MOR generate earthquakes, whereas the related fracture zones do not. (See fig. 4.22a)
21. Define hot spot. (Also see p. 8G)
22. Explain how the chain of islands in the Hawaiian Archipelago formed. (Also see fig. 4.24)
23. Explain why the Hawaiian Islands become progressively older towards the northwest. (See fig. 4.24a)
Use fig. 4.25 on p. 94 to answer the following questions (Also refer to fig. 4.10 and the inside front cover map)
24. Give an example (geographic location) of an embryonic stage in the life cycle of an ocean.
25. Give an example of a juvenile stage in the life cycle of an ocean.
26. Give an example of a mature stage in the life cycle of an ocean.
27. Give an example of a declining stage in the life cycle of an ocean.
28. Give an example of a terminal stage in the life cycle of an ocean.
29. Give an example of a suturing stage in the life cycle of an ocean.