| A | B |
|---|
| faults | surface along which rocks move when they pass their elastic limit and break |
| earthquake | vibrations produced when rocks break along a fault |
| normal fault | break in rock caused by tension forces |
| reverse fault | break in rock caused by compressive forces |
| strike-slip fault | break in rock caused by shear forces |
| seismic waves | wave generated by an earthquake |
| focus | the point below the earth's surface where energy is released in seismic waves |
| Primary waves | seismic wave that moves rock back and forth in same direction of wave |
| Secondary waves | moves rock particles in right angles to the direction of the wave |
| Surface waves | moves rock up and down in a backward rolling motion and side to side sway motion |
| epicenter | point on Earth's surface directly above and earthquakes focus |
| seismograph | instrument used to register earthquake waves and record time |
| magnitude | measure of energy released during an earthquake |
| liquefaction | wet soil acts more like a liquid during an earthquake |
| tsunamis | sea wave that begins over earthquake focus |
