| Term | Definition |
|---|
| Fault | surface along which rocks break & move |
| Earthquake | vibrations caused by breaking rocks along faults; most result from plates moving over, under, & past eachother |
| Normal Fault | break in rock due to tension forces, where rock above the fault surface moves downward in relation to rock below the fault surface |
| Reverse Fault | break in rock due to compression forces, where rocks above the fault surface move upward & over the rocks below the fault surface |
| Strike-Slip Fault | Break in rock due to shearing forces, where rocks on either side of the fault surface move past eachother with little upward or downward movement |
| Seismic Wave | energy waves that are produced at & travel outward from the earthquake |
| Focus | in an earthquake, the point beneath Earth's surface where energy release occurs |
| Primary Wave | waves that travel outward from an earthquake's focus & cause particles in rocks to move back & forth in the same direction the wave is moving (slinky) |
| Secondary Wave | waves that travel outward from an earthquake's focus & move through the Earth by causing particles in rocks to vibrate at right angles to the direction of the wave. (rope) |
| Epicenter | point on Earth's surface directly above an earthquake's focus |
| Surface Waves | waves of energy that reach Earth's surface during an earthquake, travel outward from the epicenter, and move rock particles up & down & side to side |
| Inner Core | very dense, SOLID center of Earth that is made mostly of iron with smaller amounts of oxygen, silicon, sulfur or nickel |
| Outer Core | LIQUID core that surrounds Earth's solid inner core& that is made mostly of iron |
| Mantle | largest layer inside Earth, lying directly above the outer core & that is made mostly of silicon, oxygen, magnesium, and iron |
| Crust | Earth's outermost layer, which varies in thickness from 5 km to 60 km and is seperated from the mantle by the Moho discontinuity |
| Seismologist | scientist who studies earthquakes & seismic waves |
| Seismograph | device used by seismologists to record primary, secondary & surface waves from earthquakes |
| Magnitude | measure of the energy released by an earthquake |
| Tsunamis | powerful seismic sea wave that can travel 1000s of kilometers in all directions & that begins over an earthquake's focus |
Combine with other sets
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