Plate Tectonics Vocab
Across
- 4. the study of changes in Earth's magnetic field, as shown by patterns of magnetism in rocks that have formed over time
- 6. the theory that proposes the Earth's outer shell consists of individual plates that interact in numerous ways. These plates can produce volcanoes, earthquakes, mountains, and the crust
- 8. the thin, rocky, outer layer of Earth
- 10. a chain of volcanic islands generally located a few hundred kilometers from a trench where subduction of one oceanic slab beneath another is occurring
- 12. a boundary by which two plates move together
- 14. one of the numerous rigid sections of the lithosphere that moves as a unit over the asthenosphere
- 16. a mechanism that contributes to plate motion in which cool, dense oceanic crust sinks into the mantle and pulls the lithosphere along
- 17. the motion of matter from changes in temperature
- 19. the solid innermost layer of Earth (1220 km in radius)
- 20. a boundary where two plates slide past each other without creating nor destroying the lithosphere
- 22. a proposed supercontinent that began to break about 200 million years ago and formed today's landmasses
- 23. a layer beneath the mantle (2260 km thick) containing liquid iron and generating Earth's magnetic field
- 24. a mechanism that may contribute to plate motion; it involves the oceanic lithosphere sliding down the oceanic ridge due to gravity
- 25. The rigid outer layer of Earth, including the crust and upper mantle
Down
- 1. the process by which oceanic crust sinks beneath a trench back to the mantle al a colliding plate boundary
- 2. mountains formed in part by volcanic activity caused by the subduction of oceanic lithosphere beneath a continent
- 3. The 2890 km thick layer of Earth below the crust
- 5. a region where the rigid plates are moving apart, typified by the oceanic ridges
- 7. a mass of hotter than normal mantle material that ascends toward the surface, where it can lead to igneous activity
- 9. deep faulted structure found along the axes of divergent plate boundaries (can develop on seafloor or land)
- 11. the process which plate tectonics produce new oceanic lithospheres at the ocean ridges
- 13. Ocean Trench / topographic depression of the sea floor
- 15. a hypothesis that states the continents were once a supercontinent but, are now moving
- 18. A sound navigation and ranging tool that calculates ocean depth by recording the time of an energy pulse
- 21. a weak plastic layer of the mantle below the lithosphere