click below
click below
Normal Size Small Size show me how
Earthquakes
Terminology associated with Earthquakes
| Term | Definition |
|---|---|
| aftershock | An earthquake that occurs after a larger earthquake in the same area. |
| anticline | An upwrd fold in rock formed by compression of Earth's crust. |
| base-isolated building | A building mounted on bearings designed to absorb the energy of an earthquake. |
| compression | Stress that squeezes rock until it folds or breaks |
| deformation | A change in the volume or shape of Earth's crust |
| earthquake | The shaking that results from the movement of rock beneath Earth's surface. |
| epicenter | The point on Earth's surface directly above an earthquake's focus |
| fault | A break in Earth's crust where slabs of rock slip past each other |
| fault-block mountain | A mountain that forms where a normal fault uplifts a block of rock |
| focus | The point beneath Earth's surface where rock breaks under stress and causes an earthquake |
| fold | A bend in rock that forms where part of Earth's crust is compressed |
| footwall | The block of rock that forms the lower half of a fault |
| hanging wall | The block or rock that forms the upper half of a fault |
| liquefaction | the process by which an earthquake's violent movement suddenly turns loose soil into liquid mud |
| magnitude | the measurement of an earthquake's strength based on seismic waves and movement along faults |
| Mercalli scale | a scale that rates earthquakes according to their intensity and how much damage they cause |
| moment magnitude scale | a scale that rates earthquakes by estimating the total energy released by an earthquake |
| normal fault | a type of fault where the hanging wall slides downward; caused by tension in the crust |
| P wave | a type of seismic wave that compresses and expands the ground |
| plateau | a large area of flat land elevated high above sea level |
| reverse fault | a type of fault where the hanging wall moves up and over the footwall; caused by compression in the crust |
| Richter scale | a scale that rates seismic waves as measured by a particular tpe of mechanical seismograph |
| S wave | a type of seismic wave that moves the ground up and down or side to side |
| seismic wave | a vibration that travels through Earth carrying the energy released during an earthquake |
| seismograph | a device that records ground movements caused by seismic waves as they move through the Earth |
| shearing | stress that pushes a mass of rock in opposite directions |
| stress | a force that acts on rock to change its shape or volume |
| strike-slip fault | a type of fault where rocks on either side move past each other sideways with little up or down motion |
| surface wave | a type of seismic wave that forms when P waves and S waves reach Earth's surface |
| syncline | a downward fold in rock formed by compression in Earth's crust |
| tension | stress that stretches rock so that it beomes thinner in the middle |
| tsunami | a large wave produced by an earthquake on the ocean floor |