Across
- 4. a depression of Earth's surface in which an ocean lies
- 6. huge pieces of lithosphere that slowly move on the asthenosphere and consist of the crust and the rigid, uppermost part of the mantle
- 8. melted or molten rock material beneath Earth's surface; cools slowly to form rocks with larger crystals
- 10. the process of forming something by forcing or pushing it out
- 11. a deep and narrow depression in the seafloor where the subducted plate moves into the asthenosphere
- 13. a mountain range that is found on the ocean floor
- 15. when two tectonic plates move away from each other
Down
- 1. a dense, destructive mass of very hot ash, lava fragments, and gases ejected explosively from a volcano and typically flowing downslope at great speed
- 2. when two tectonic plates move towards each other, sometimes forming mountains
- 3. the formation of new areas of oceanic crust, which occurs through the upwelling of magma at midocean ridges and its subsequent outward movement on either side
- 5. the thin, solid, outermost layer of Earth; made of less dense silicates and is either continental (landmasses) or oceanic (ocean floors)
- 7. it causes a fault between two plates of the lithosphere, which will slide past one another
- 9. the process in which a denser plate is pushed downward beneath a less dense plate when plates converge; occurs at continental to oceanic boundaries and oceanic to oceanic boundaries
- 12. a hot liquid that comes from the mantle
- 14. an underwater mountain system formed by plate tectonics; the largest single volcanic feature on Earth