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Brechbill ch 6
Earthquakes
| Question | Answer |
|---|---|
| This type of fault is created by compressional forces and causes rocks to move upward. | Reverse fault |
| The point below earth's surface where earthquakes originate. | Focus |
| The paper record of a seismic event. | seismogram |
| The point on earth's surface directly above the earthquakes focus. | epicenter |
| Describes the strength of an earthquake based on the height of the waves on a seismogram. Measured in decimals. | Richter Scale |
| Seismic wave that moves particles back and forth in same direction the wave travels. | Primary wave |
| The measure of the energy released during an earthquake. | magnitude |
| Vibrations produced when rocks break. | earthquake |
| Instrument used to measure an earthquake and record the arrival times of P and S waves. | seismograph |
| This type of fault is created by tension forces and causes the rock to move downward. | normal fault |
| Weak places in earth's crust where rocks break because they have reached their elastic limit. | faults |
| Faults created by shear forces that cause rocks to slide past one another. | strike-slip fault |
| The waves generated by an earthquake are called _____ waves. | seismic |
| The seismic wave that moves rock at right angles to the direction of the wave. | secondary wave |
| The seismic wave that moves rock up and down, and side to side in a swaying motion. | surface wave |
| Measures the intensity and damage that an earthquake caused. It is measured in roman numerals from I to VII. | Mercalli Scale |
| Occurs during an earthquake when wet soil behaves more like a liquid. | liquifcation |
| Seismic sea wave that begins over an earthquake focus that occurs in oceanic crust. | tsunami |
| Primary waves travel the _____ and arrive at the seismograph station _____. | fastest; first |
| Secondary waves travel _____ and arrive at the seismograph station ______. | slower; second |
| Surface waves travel _____ and are the most _____. | slowest; destructive |