Plate Tectoics

1. The solid, outer layer of the Earth that consists of the crust and the rigid upper part of the mantle.
5. The boundary between two tectonic plates that are moving away from each other.
7. The hypothesis that states that the continents once formed a single landmass, broke up, and drifted to their present locations.
10. The process by which new oceanic lithosphere forms as magma rises toward the surface and solidifies.
12. Vibrations created by an earthquake.
15. A block of lithosphere that consists of the crust and the rigid, outermost part of the mantle.
16. The boundary between tectonic plates that are sliding past each other horizontally.
17. The rising of regions of the Earth's crust to higher elevations.
18. The sinking of regions of the Earth's crust to lower elevations.

2. Stress that occurs when forces act to stretch an object.
3. The boundary formed by the collision of two lithospheric plates.
4. The layer of rock between the Earth's crust and core.
6. Stress that occurs when forces act to squeeze an object.
7. The central part of the Earth below the mantle.
8. The bending of rock layers due to stress.
9. The soft layer of the mantle on which the tectonic plates move.
11. The theory that explains how large pieces of the Earth's outermost layer, called tectonic plates, move and change shape.
12. Machines that measure the times at which seismic waves arrive at different distances from an earthquake.
13. The thin and solid outermost layer of the Earth above the mantle.
14. A break in a body of rock along which one block slides relative to another.