Plate Tectonics Review

6. areas that are below sea level
10. a volcanically active area of Earth's surface far from a tectonic plate boundary
12. theory that Earth's continents move or drift relative to each other over geologic time
13. a principle that states that younger rocks lie above older rocks if the layers have not been disturbed
14. an ancient landmass which separated into present-day continents
15. The shaking that results from the movement of rock beneath Earth's surface.
16. Massive volcano that can produce unbelievably enormous, but rare, eruptions.
17. A trace of an ancient organism that has been preserved in rock.
21. A plate boundary where two plates move toward each other.

1. Magma that reaches the Earth's surface
2. The boundary between tectonic plates that are sliding past each other horizontally
3. A break in the Earth's crust
4. A weak spot in the crust where magma has come to the surface
5. Sections of the Earth's crust that move due to convection currents in the mantle
7. Molten rock beneath the Earth's surface
8. A plate boundary where two plates move away from each other.
9. A scale that rates an earthquake's magnitude based on the size of its seismic waves.
11. caused by the rising of heated fluid and sinking of cooled fluid
18. vibrations that travel through Earth carrying the energy released during an earthquake
19. One plate going under another plate
20. well-tested explanation that unifies a broad range of observations