| A | B |
|---|
| fault | places where rock is moving in different directions |
| earthquake | breaking rock that produces a vibration |
| normal fault | tension that pulls rock apart |
| reverse fault | compression that pushes rock from opposite directions |
| stike-slip fault | rock that is moving past each other. Irregular surfaces catch and pressure builds up |
| seismic wave | waves produced by an earthquake |
| focus | point in the earth's interior where energy is released |
| primary wave | waves that cause rock to move back and forth in the same direction |
| secondary wave | waves that move at right angles to the primary wave |
| epicenter | point on the earth's surface above the focus |
| surface wave | elliptical and back and forth motion. cause the most damage |
| inner core | dense solid center of the earth |
| outer core | liquid layer of the earth's core that surrounds the solid inner core |
| mantle | largest layer of the earth's interior |
| crust | very thin layer that makes up the earth's surface |
| Moho discontinuity | boundary between the crust and the mantle |
| seismologist | a scientist who studies earthquakes |
| seismograph | instrument that records primary, secondary, and surface waves |
| magnitude | a measure of the energy released by an earthquake |
| tsunamis | an earthquake generated wave. can reach 30 meters in height at the shore |
