| A | B |
|---|
| Fault | Surface along which a rock moves when they pass their elastic limit and break. |
| Earthquake | Vibrations produced when rock breaks along a fault. |
| Normal Fault | Break in rock caused by tension forces, where rock above the fault surface moves down relative to the rock below the fault surface. |
| Reverse Fault | Break in rock caused by compressive forces, where rock above the fault surface moves upward. |
| Strike-slip Fault | Break in rock caused by shear forces, where rock moves past each other without much vertical movement. |
| Seismic Wave | Wave generated by an earthquake. |
| Focus | In an earthquake, the point below the Earth's surface where energy is realeased in the form of seismic waves. |
| Primary Wave | Seismic wave that moves rock particles back and forth in the same direction that the wave travels. (compression waves) |
| Secondary Wave | Seismic wave that moves rock particles at right angles to the direction of the wave. (shearing waves) |
| Epicenter | Point on Earth's surface directly above an earthquake's focus. |
| Seismograph | Instrument used to register an earthquake's waves and record the time that each arrived. |
| Surface Wave | (Raleigh and Love Waves) Seismic wave that moves rock particles up and down in a backward rolling motion or side to side in a swaying motion. |
| Magnitude | Measure of the energy released during an earthquake. |
| Liquefaction | Occurs when wet soild acts more like a liquid during an earthquake. |
| Tsunami | Seismic sea wave that begins over an earthquake focus and can be highly destructive when it crashes on shore. |
| Mercalli Scale | Scale used for measuring the INTENSITY of an earthquake. |
| Richter Scale | (has no upper limit) Scale used for measuring the ENERGY RELEASED during an earthquake. |
