3. most of the earth's volcanic and earthquake activity occurs a. in the center of continents. b. at the shores of continents. c. in the center of lithosphere plates d. at the edges of lithosphere plates. 4. the eastern edge of the north american continent is not the same as the eastern boundary of the north american plate. the eastern edge of the north american continent is a. the shoreline because ocean lithosphere begins where the ocean water meets the land. b. the shoreline because a plate cannot contain both continental and oceanic lithosphere. c. the edge of the continental shelf because that is where continental crust ends and oceanic crust begins. d. the mid-atlantic ridge because that is where seafloor spreading is taking place. 5. the eastern edge of the north american plate is a. the shoreline because ocean lithosphere begins where the ocean water meets the land. b. the shoreline because a plate cannot contain both continental and oceanic lithosphere. c. the edge of the continental shelf because that is where continental crust ends and oceanic crust begins. d. the mid-atlantic ridge because that is where seafloor spreading is taking place. and is 6. in the tectonic cycle, new lithosphere forms at consumed at a. ocean ridges, subduction zones b. ocean ridges; transform faults c. transform faults, subduction zones d. subduction zones, transform faults 7. at which locations is volcanic activity abundant? a. oceanic ridges b. subduction zones where ocean lithosphere is shoved into the mantle beneath continental lithosphere c. subduction zones where ocean lithosphere is shoved into the mantle beneath oceanic lithosphere d. volcanic activity is found at all of these locations. 8. earthquakes occur frequently at a. ocean ridges. b. subduction zones. c. transform faults. d. ocean ridges, subduction zones, and transform faults. 9. at what type of plate boundary is there no vertical transfer material between the lithosphere and asthenosphere? a. subduction zone b. transform fault c. oceanic ridge d. vertical transfer occurs at all plate boundaries, 10. the presence of tropical plants and animals hundreds of millions of years old near the north pole suggests that a. the earth's surface has cooled significantly since those organisms died. b. the earth's surface has warmed significantly since those organisms died. c. the earth's axis shifted suddenly, causing those organisms to become extinct. d. the plate on which those organisms are found has moved from a different climate zone to its current arctic position. 11. the earth's magnetic field a. is caused by a giant bar magnet in the core. b. generates lines of force that parallel the earth's surface at the equator. c. can be measured only in the oceans. d. reverses polarity at regular intervals of approximately 10 million years. 12. magnetic anomaly stripes" in the oceans are caused by a. the fluctuating strength of the earth's current magnetic field. b. a combination of the earth's current magnetic field and ancient magnetic fields at the time the oceanic rocks formed. c. earthquakes at ocean ridges that disrupt the magnetic field. d. transform faults. 13. the himalayan mountain system formed when a. an ocean that once separated india and asia closed by subduction b. a transform fault brought the two continental masses together. c. an ocean ridge began to form in the middle of a single lithosphere plate. d. a meteorite struck in the middle of asia. 14. volcanic arcs form above subduction zones a. only where oceanic lithosphere is subducted beneath other oceanic lithosphere. b. only where oceanic lithosphere is subducted beneath continental lithosphere. c. wherever oceanic lithosphere is subducted. d. because of rifting near the oceanic trench. 15. a seamount forms when a. rifting occurs along an ocean ridge. b. a volcano is eroded by waves and sinks as it becomes denser with time. c. subduction raises part of the ocean floor. d. lava erupts from a transform fault.