____15. What do you call the process when the oceanic crust moves downward towards the
trench at the subduction zone?
a. convection c. slab pull
b. ridge push d. subduction
____16. Which of the following is referred into when the weight of subducting plate
falls/descents toward the subduction zone?
a. convection c. slab pull
b. ridge push d. subduction
____17. What does Plate Tectonic Theory predict about the distribution of volcanoes and
earthquakes?
a. They should be evenly distributed throughout the earth.
b. They should occur primarily along plate boundaries.
c. They should occur primarily along deep ocean basin.
d. They should occur primarily along continents.
____18. What has become accepted as the primary mechanism for seafloor spreading?
a. Density differences in the crust c. Weight of seafloor sediments
b. Convection currents in the mantle d. All of these
____19. How is oceanic crust forced back into the earth’s mantle?
a. It sinks because it is made of high density materials.
b. It sinks because it is cold and therefore dense.
c. It sinks because of its high iron content.
d. It floats because it curls as it cool down.
____20. What inner layer of the earth does convection currents exists?
a. crust c. mantle
b. inner core d. outer core