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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. |