| A | B |
|---|
| Seismograph | A device that records ground movements caused by seismic waves as they move through the Earth |
| S Waves | A type of seismic wave that moves the ground up and down or side to side |
| Surface Waves | A type of seismic wave that forms when P waves and S waves reach the surface |
| P Waves | A type of seismic wave that compresses and expands the ground |
| Seismic waves | A vibration that travels through the Earth carrying the energy released during an earthquake |
| Focus | The point beneath Earth's surface where rock breaks under stress and causes an earthquake |
| Epicenter | The point on Earth's surface dircetly above an earthquake's focus |
| Magnitude | The measurement of an earthquake's strength based on seimic waves and movement along faults |
| Moment Magnitude Scale | A scale that rates earthquakes by estimating the total energy released by an earthquake |
| Mercalli Scale | A scale that rates earthquakes according to their intensity and how much damage they cause |
| Richter Scale | A scale that rates seimic waves as measured by a particular type of mechanical seismograph |
| What scale is currently being used to measure the magnitude of an earthquake? | Moment Magnitude Scale |
| What other scales have been used to measure the magnitude of an earthquake? | Mercalli and Richter Scales |
| What kind of waves do earthquakes produce? | seimic waves, P waves and S waves |
