Earth Space Chapter 19

Point on Earth's surface directly above the focus of an Earthquake

Fracture or system of fractures in Earth's crust that occurs when stress is applied too quickly or stress is too great, can for as a result of horizontal compression, horizontal shear, or horizontal tension.

Point of the initial fault rupture when an earthquake originates that usually lies at least several kilometers beneath the earths surface

Seismic wave that squeezes and pulls rocks in the same direction that the wave travels, causing rock particles to move back and fourth

Seismic wave that causes rock particles to move at right angles to the direction of the wave

Deformation of materials in response to stress

Forces per unit area that act on material, compression, tension, shear

Seismic wave that moves in 2 directions as it passes through rocks, causing the ground to move both up and down and from side to side

Record produced by a seismometer that can provide individual tracking of each type of seismic wave

Instrument used to measure horizontal and vertical motion during and earthquake

Measure of the energy released during an earthquake

Measures earthquake intensity

Scale used to measure earthquake magnitude taking into account the size of fault rupture, the rocks stiffness, and amount of movement along the fault

Numerical scale used to measure the magnitude of an earthquake using values based on the size of several types of seismic waves

Place along an active fault that has not experienced an earthquake for a long time