PLATE TECTONICS

4. A devastating catastrophe caused by geological processes
6. Occurs when two rocks are pressed together and one block rides up to overlay the other.
7. The process of denser crust of a tectonic plate sliding beneath less dense crust of another plate; occurs at convergent plate boundaries and produces deep sea trenches.
8. Mountain ridges run along the seafloor.
13. An instrument that measures and records ground vibration.
15. The point on earths surfaces above where an earthquake starts.
16. In mid ocean ridges a valley that runs along the centre of the ridge.
17. A large break in a rock.
20. An opening in earths surface where magma and other materials are released.
21. Deep valleys on the seafloor.
22. When new material at mid-ocean ridges pushes older material aside, tectonic plates shift.
23. A ground-shaking release of energy caused by a break in the crust.
24. A layer of earth between the crust and outer core, which is divided into upper and lower sections.

1. Is the separation of two tectonic plates.
2. Is a current in the mantle that occurs when cooler, denser material sinks and warmer, less dense material rises.
3. Is the point at which two tectonic plates collide.
5. The vibration caused by the release of energy during an earthquake.
9. The belief that the Earth's continents have been in the same place since the Earth's formation.
10. The lithosphere is divided into large plates that interact with one another and cause geological activity.
11. is the gravitational and subduction-induced pulling of a tectonic plate.
12. In earth science, the location within earth where an earthquake starts.
14. The process by which magma rises to the surface at mid-ocean ridges and forms new ocean crust.
18. For earthquakes, a number that represents strength.
19. Two tectonic plates slide horizontally past each other.