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7GrInEarCh2 Sec. 2
7th Grade Inside Earth Chapter 2 Sec. 2
Question | Answer |
---|---|
earthquake | the 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 | waves that move slower than P and S waves but produce severe ground movements |
Mercalli scale | a scale to rate earthquakes according to the level of damage at a given place |
magnitude | a number geologists assign to an earthquake based its size |
Richter scale | rating of an earthquake's magnitude based on the size of its seismic waves |
seismograph | instrument that measures seismic waves |
moment magnitude scale | rating system that estimates the total energy released by an earthquake |
liquefaction | when the earthquake's violent shaking suddenly turns loose soft soil into liquid mud |
aftershock | an earthquake that occurs after a larger earth quake in the same area |
tsunami | a large wave caused by an earthquake |
base isolated building | building designed to reduce the amount of energy that reaches the building during an earthquake |