| A | B |
|---|
| earthquake | a movement or trembling of the ground that is cused by a sudden release of energy when rocks along a fault move |
| elastic rebound | the sudden return of elastically deformed rock to its undeformed shape |
| seismic wave | a wave of energy that travels through the Earth and away from an earthquake in all directions |
| P wave | fastest seismic waves - also called pressure or primary waves - can travel through solids, liquids and gases |
| S wave | second-fastest seismic waves - cannot travel through parts of Earth that are completely liquid |
| surface wave | wave that moves only along Earth's surface and is the most destructive |
| epicenter | the point on Earth's surface directly above an earthquake's starting point, or focus |
| focus | the location within Earth along a fault at which the first motion of an earthquake occurs |
| magnitude | a measure of the strength of an earthquake |
| intensity | in Earth science, the amount of damage caused by an earthquake |
| seismic gap | an area along a fault where relatively few earthquakes have occurred recently but where strong earthquakes have occurred in the past |
| tsunami | a giant ocean wave that forms after a volcanic eruption, submarine earthquake, or landslide |
