| A | B |
|---|
| after shock | a smaller earthquake that follows a larger earthquake |
| body waves | waves of energy that travel from the focus of an earthquake through the material of the earth's body |
| earthquake | the shaking of the earth's crust caused by a release of energy |
| epicenter | the point on earth's surface directly above the focus of an earthquake |
| fault | a break in the lithosphere along which earth movement has occured |
| focus | the surface point at which the first movement occurs during an earthquake |
| liquefaction (not liquification) | a temporary state in which loose soil and rock materials take on the property of liquid |
| magnitude | the measure of the amount of energy released in an earthquake |
| P waves | body waves that squeeze and stretch rock materials as they pass through earth |
| S waves | body waves that cuase particles of rock material to move at right angles to the direction in which waves are traveling |
| seismic gap | an area along a seismically active fault where no earthquake activity has occured |
| seismogram | the recording of an earthquake made by a seismograph |
| seismograph | an insrument that detects and records waves produced by earthquakes |
| surface waves | earthquake waves that travel along earth's surface |
| tsunami | a large ocean wave that results from an underwater earthquake, landslide, or volcanic eruption |
