Across
- 1. Ring of Fire a major area in the Pacific Ocean where a large number of earthquakes and volcanic eruptions occur.
- 5. Arc a curved chain of volcanic islands located at a tectonic plate margin.
- 7. the upper layer of the earth's mantle, below the lithosphere.
- 9. drift the gradual movement of the continents across the earth's surface through geological time.
- 10. crust the uppermost layer of the oceanic portion of a tectonic plate.
- 11. a sudden and violent shaking of the ground, sometimes causing great destruction, as a result of movements within the earth's crust or volcanic action.
- 12. Zone a geological process that takes place at convergent boundaries of tectonic plates where one plate moves under another and is forced or sinks due to gravity into the mantle.
- 14. ridges an underwater mountain range, formed by plate tectonics.
- 15. boundary two tectonic plates that are moving away from each other.
- 16. boundary a type of fault whose relative motion is horizontal.
Down
- 1. the study of the record of the Earth's magnetic field in rocks, sediment, or archaeological materials.
- 2. a mountain or hill, typically conical, having a crater or vent through which lava, rock fragments, hot vapor, and gas are being or have been erupted from the earth's crust.
- 3. rigid outer part of the earth, consisting of the crust and upper mantle.
- 4. tectonics theory explaining the structure of the earth's crust and many associated phenomena.
- 6. crust the relatively thick part of the earth's crust that forms the large landmasses.
- 8. a hypothetical supercontinent that included all current land masses, believed to have been in existence before the continents broke apart during the Triassic and Jurassic Periods.
- 9. movement caused within a fluid/solid by the tendency of hotter and therefore less dense material to rise, and colder, denser material to sink under the influence of gravity.
- 13. boundary two (or more) tectonic plates or fragments of the lithosphere move toward one another and collide.
- 17. a fracture in Earth's surface that widens over time.