| A | B |
|---|
| faults | rocks that break and move along a surface where the rock has broken |
| earthquakes | vibrations of the Earth's crust caused by rocks breaking |
| normal fault | caused by tension forces |
| reverse fault | caused by compression forces |
| strike-slip fault | caused by shearing forces |
| elastic limit | maximum amount of force that can be applied before rock breaks |
| seismic waves | energy generated by an earthquake |
| focus | the point where the earthquake occured |
| epicenter | the point on the Earth's surface directly above the earthquake |
| primary waves | causes rock to vibrate back and forth |
| secondary waves | causes rock to move at right angles to the direction of the wave |
| surface waves | particles move in an elliptical motion and a back and forth motion |
| inner core | solid, composed of iron & nickel |
| outer core | liquid, composed of iron & nickel |
| mantle | thickest layer, made of silicon, oxygen, magnesium, and iron |
| crust | Earth's outermost layer, very thin |
| Moho discontinuity | boundary between the crust and mantle |
| seismologist | scientist who studies earthquakes |
| seismograph | instrument used to detect seismic waves |
| sesimogram | paper used to record earthquake vibrations |
| magnitude | a measure of the energy released by an earthquake |
| tsunamis | seismic sea waves; dangerous to people living on shorelines |
