1. The process by which tectonic plates move away from each other. (DIVERGENT BOUNDARY)

3. The process by which tectonic plates move toward each other. (CONVERGENT BOUNDARY)

5. The process by which tectonic plates slide past each other. (TRANSFORM BOUNDARY)

7. A large, rigid section of the Earth's lithosphere that moves as a unit. (TECTONIC PLATE)

9. The layer of the Earth's atmosphere that is closest to the surface. (TROPOSPHERE)

11. The point on the Earth's surface directly above the focus of an earthquake. (EPICENTER)

13. The magnitude of an earthquake is measured on this scale. (RICHTER SCALE)

15. A series of seismic waves that are generated by an earthquake. (SEISMIC WAVES)

17. The study of earthquakes and seismic waves. (SEISMOLOGY)

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2. The point on the Earth's surface that is directly opposite the focus of an earthquake. (ANTIPODE)

4. A large, relatively flat area of land that is surrounded by water. (CONTINENT)

6. A region of the Earth's crust that is characterized by high levels of seismic activity. (SEISMIC ZONE)

8. A mountain range that is formed when two tectonic plates collide. (COLLISIONAL OROGENY)

10. A deep, narrow valley that is formed by the movement of tectonic plates. (RIFT VALLEY)

12. A large, hot, liquid mass of rock that is found beneath the Earth's crust. (MAGMA)

14. A volcanic eruption is a process by which magma is extruded onto the Earth's surface. (VOLCANIC ERUPTION)

16. A body of water that is formed by the subsidence of a tectonic plate. (OCEAN BASIN)