Earthquakes

1. – the point within Earth where an earthquake begins.
4. – a smaller earthquake that occurs before the main earthquake.
7. – a smaller earthquake that follows the main earthquake in the same area.
9. – the process by which water-saturated soil temporarily behaves like a liquid during strong shaking.
11. – a series of large ocean waves generated by the sudden displacement of water, often caused by an undersea earthquake.
12. – the breaking and displacement of rock along a fault during an earthquake.
15. – the recorded trace produced by a seismograph.
16. – a secondary seismic wave that moves particles perpendicular to its direction of travel.
18. earthquake – an earthquake caused by the movement of tectonic plates.
19. plane – the surface along which movement occurs during faulting.

2. wave – a seismic wave that travels along Earth's surface and often causes the greatest damage.
3. – a sudden shaking of the ground caused by the release of energy within Earth's crust.
5. wave – a wave of energy that travels through Earth as a result of an earthquake or explosion.
6. – an instrument used to detect and record ground vibrations caused by earthquakes.
8. – a fracture in Earth's crust along which rocks have moved.
10. – a measure of the effects or severity of an earthquake at a particular location.
13. – a measure of the amount of energy released by an earthquake.
14. – a primary seismic wave that travels fastest and moves particles back and forth.
15. – the scientific study of earthquakes and the movement of seismic waves.
17. – the point on Earth's surface directly above the focus of an earthquake.