The belts of shallow-focus earthquakes shown by the blue dots in Figure 13.16 are wider and more diffuse on the continents than in the oceans. Why? (Hint: You might want to review Chapter 7.)
Why are earthquakes with focal depths greater than 20 km infrequent in continental lithosphere?
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Why do the largest earthquakes occur on megathrusts at subduction zones and not, say, on continental strike-slip faults?
How big would a fault have to be to produce a magnitude-10 earthquake? Do you think such a large earthquake could occur by the rupturing of subduction-zone megathrusts?
In Figure 13.3, the right-lateral fault offsets the fence line to the right. In Figure 13.17, the mid-ocean ridge crest is also offset to the right. Why, then, is the transform fault in Figure 13.17 left-lateral?
Would you support legislation to prevent landowners from building structures close to active faults?
Taking into account the possibility of false alarms, mass hysteria, economic depression, and other possible negative consequences of earthquake prediction, do you think the objective of predicting earthquakes should have a high priority?