Term
|
Definition
| Vibration on earth produced by a rapid release of energy from ruptured rocks that have undergone stress beyond their limit. Mostly occur along existing faults when fictional fault surfaces are overcome. First figure out by H.F. Reid. |
|
|
Term
|
Definition
| Source of energy causing an earthquake. The weakest point along a fault where stress is released. |
|
|
Term
|
Definition
| Large fractures in the earth's crust. Movements of these build up stress/energy and cause earthquakes when released/relieved |
|
|
Term
|
Definition
| As rocks bend, they store energy. The "springing back" of rocks to their original shape causing an earthquake. |
|
|
Term
|
Definition
| Small earthquakes that often, but NOT always, precede a major earthquake by days or even years. |
|
|
Term
|
Definition
| Adjustments that take place after a major earthquake that generate smaller earthquakes. |
|
|
Term
| Surface wave/ L-waves or long waves |
|
Definition
| Seismic wave that travels along OUTER LAYER of earth. Waves that cause the greatest destruction, have highest amplitude and lowest speed. |
|
|
Term
|
Definition
| Seismic waves which travel through Earth's INTERIOR. Has subdivision of p - and s-waves |
|
|
Term
|
Definition
| Body waves which COMPRESS or PULL rock in direction the waver is traveling. Travels through solid, liquid, and gas. |
|
|
Term
| Secondary waves (s-waves) |
|
Definition
| Body waves which "shakes" the particles in the rock. Can only travel through SOLIDS. Will NOT transmit through liquid. |
|
|
Term
|
Definition
| Location on Earth's surface directly above the focus of an earthquake. Located through process of triangulation. |
|
|
Term
|
Definition
| Process of locating the epicenter of an earthquake by using the distances measured from THREE seismic stations. |
|
|
Term
|
Definition
| Location of the principal earthquake epicenter zones. Where the greatest energy is released. |
|
|
Term
| Modified Mercalli Intensity Scale |
|
Definition
| Scale that uses damages to building in California to estimate the intensity of ground shaking for a local earthquake. |
|
|
Term
|
Definition
| Estimation of the amount of ENERGY released at the source of the earthquake based on seismic records. |
|
|
Term
|
Definition
| First seismic scale using seismic records to estimate the relative sizes of earthquakes. Magnitude of an earthquake is estimated by measuring the amplitude (maximum displacement) of the largest seismic wave recorded. |
|
|
Term
|
Definition
| A calculation of average displacement of the fault, the area of the fault surface, and the sheer strength of the faulted rock. Used to estimate the size of moderate and large earthquakes. |
|
|
Term
|
Definition
| A secondary effect of an earthquake that is a surface affecting the ocean. |
|
|
Term
|
Definition
| Most studied fault in the world. |
|
|
Term
|
Definition
| Slow, gradual displacement along fault. Occurs relatively smoothly and has little noticeable seismic activity. |
|
|
Term
|
Definition
| Study of earthquakes. Dates back to almost 2000 years ago in China which an ancient Chinese seismograph. |
|
|
Term
|
Definition
| Instrument that records seismic waves. Must have a mass freely suspended to record any vibration usually on a rotating drum or magnetic tape. Since movement of Earth happens both vertically and horizontally, more than one type of this is needed. Produces seismograms. |
|
|
Term
|
Definition
| Surface wave that acts like an ocean wave moving along the surface of the Earth. |
|
|
Term
|
Definition
| Surface wave similar to S-Wave, but moves PARALLEL to Earth's surface. Create a side-to-side motion along surface that is particular damaging to structures. |
|
|
Term
|
Definition
| Occurs when unconsolidated materials (such as moist soil) are saturated with water. The vibration caused by earthquakes causes the water to rise up so the surface layer loses cohesiveness. Can cause underground objects such as storage tanks to float to the surface. |
|
|
Term
|
Definition
| Destructive force caused by seismic vibrations. It is the rhythmic sloshing of waves in lakes, reservoirs, and enclosed basins. |
|
|
