Plate Tectonic

5. the upper layer of the earth's mantle, below the lithosphere, in which there is relatively low resistance to plastic flow and convection is thought to occur.
9. A long, narrow, but very deep depression in ocean floor.
10. The process by which sounds waves travel through medium.
11. the outer layer of the Earth, between the surface and the mantle
13. An elastic wave in the earth produced by an earthquake.
15. The concept that new oceanic crust is created at the mid ridges as a result of divergence between plate.
16. Plates moving toward each other.
17. A boundary in which two plates slide past each other.
18. A solid sphere in the middle of the core.

1. one of the sections of the earth's lithosphere.
2. The outer solid part of the earth, including the crust and uppermost mantle.
3. The site where tectonic plates move apart and new oceanic crust creates.
4. the layer of the earth between the crust and the outer core.
6. A theory that explains scientific observation.
7. The theory that the earth's surface is divided into few large, thick plates that are constantly moving.
8. A current in a fluid that result from convection.
12. Plates that moves away from each other.
14. The gradual movement of the continental across the earth's surface.