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Science
Chapter 4 Lesson 2
| Term | Definition |
|---|---|
| Earthquake | Is the shaking and trembling that results from movement of rock beneath Earth's surface. |
| Focus | Is the area beneath earth's surface where rock that was under stress begins to break or move. |
| Epicenter | Is the point on the surface that is directly above the focus. |
| P waves | Are seismic waves that compress and expand the ground like an accordion. |
| S waves | Are seismic waves that can vibrate from side to side. |
| Surface waves | Is when P waves and S waves reach a surface they become surface waves. |
| Seismograph | Is an instrument that records and measures an earthquake's seismic waves |
| Modified Mercalli Scale | Is a scale that rates the amount of shaking from an earthquake. |
| Magnitude | Is a single number that geologists assign to an earthquake based on the earthquakes size. |
| Richter scale | Is an early magnitude scale which other scales are based upon. |
| Moment Magnitude Scale | Is a scale to rate the total energy an earthquake releases. |