PLATE TECTONICS

2. 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.
4. A ground-shaking release of energy caused by a break in the crust.
7. In mid ocean ridges a valley that runs along the centre of the ridge.
10. is the gravitational and subduction-induced pulling of a tectonic plate.
13. WAVES The vibration caused by the release of energy during an earthquake.
16. For earthquakes, a number that represents strength.
20. Mountain ridges run along the seafloor.
21. Is the point at which two tectonic plates collide.
23. An instrument that measures and records ground vibration.
24. A layer of earth between the crust and outer core, which is divided into upper and lower sections.

1. Is a current in the mantle that occurs when cooler, denser material sinks and warmer, less dense material rises.
3. The process by which magma rises to the surface at mid-ocean ridges and forms new ocean crust.
5. Is the separation of two tectonic plates.
6. Two tectonic plates slide horizontally past each other.
8. An opening in earths surface where magma and other materials are released.
9. A large break in a rock.
11. The belief that the Earth's continents have been in the same place since the Earth's formation.
12. Occurs when two rocks are pressed together and one block rides up to overlay the other.
14. The lithosphere is divided into large plates that interact with one another and cause geological activity.
15. A devastating catastrophe caused by geological processes
17. Deep valleys on the seafloor.
18. The point on earths surfaces above where an earthquake starts.
19. When new material at mid-ocean ridges pushes older material aside, tectonic plates shift.
22. In earth science, the location within earth where an earthquake starts.