| A | B |
|---|
| earthquake | a sudden shift of a plate causing a large release of energy |
| P-waves | a body wave that travels first, through both liquid and solid, and is detected at distant seismograph stations |
| S-waves | a body wave that arrives second, travels through solids only, and is also called a shear wave |
| focus | the actual origin of an earthquake below the surface |
| epicenter | the location on the surface directly above the focus of an earthquake |
| body waves | waves inside the earth (p and s waves) |
| surface waves | these waves cause the most damage and travel more slowly than p and s waves |
| seismograph | a detection device that records earthquake activity |
| seismogram | a representation of earthquake activity from a seismograph |
| triangulation | the process of locating an epicenter by using data from 3 different seismograph stations |
| magnitude | the strength of an earthquake measured on a seismogram and used by the richter scale |
| Mercalli Scale | the subjective method of epicenter locating |
| Richter Scale | utilizes magnitude and amplitude to detect energy released during a seismic event |
| liquefaction | loose soil temporarily takes on properties of a liquid increasing damage during a quake |
| tsunami | a large wave created by activity underwater including seismic events |
| seismic gaps | an area along the fault where earthquake activity has not been present recently |
| the shadow zone | the area inside the earth directly across from an eq focus that cannot read P and S waves due to refraction of the waves |
| Moho | the area where the velocity of an earthquake wave changes because of density differences between the crust and the mantle |
