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Science 2-2
Earthquakes and Seismic Waves
| Term | Definition |
|---|---|
| Earthquake | Shaking and trembling that results from the movement of rock beneath Earth’s surface. |
| Focus | The area beneath Earth’s surface where rock that is under stress breaks, triggering an earthquake. |
| Epicenter | The point on the surface directly above the focus |
| P-waves | Seismic waves that compress and expand the ground like an accordion. |
| S-waves | Seismic waves that vibrate from side to side as well as up and down. |
| Surface Waves | Move more slowly than P waves and S waves, but they can produce severe ground movements. |
| Mercalli Scale | To rate earthquakes according to the level of damage at a given place. |
| Magnitude | A number that geologists assign to an earthquake based on the earthquake’s size. |
| Richter Scale | A rating of an earthquake’s magnitude based on the size of the earthquake’s seismic waves. |
| Moment Magnitude Scale | A rating system that estimates the total energy released by an earthquake. |
| Locating the epicenter | Scientists find three areas and locate how far the earthquake is from the place and draw circles that far and the three circles that intersect is where the epicenter is. |