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