Tectonic Activity

4. rigid, rocky outer layer of Earth, consisting of the crust and the solid outermost layer of the upper mantle
6. sea-floor mountain system
9. Earth's crust that makes up the continents
12. a linear-shaped lowland between several highlands
13. a vibration of the Earth's surface due to the tremendous release of energy

1. two plates move towards each other
2. a fracture that separates one plat from another
3. Earth's crust that makes up the oceans
5. a steep depressions in the deepest parts of the ocean
7. two plates moving apart
8. two plates slide horizontally past each other
10. a natural elevation of the earth's surface rising more or less abruptly to a summit,
11. an opening in a crust through which molten rock, hot gases, and other materials erupt.