Earth Science (EARTH-1141) - Structure/Earthquakes Vocab

5.1-5.7

earthquake

vibration of the earth produced by the rapid release of energy. radiates in all directions as waves and dissipates rapidly with distance. caused by the build up of pressure at faults

stick slip motion

tectonic creep

fault

a break in a rock mass along which movement has occured

focus

in an earthquake, the location within earth where slippage begins - location of break

epicenter

surface of the earth above where the focus is, where the earthquake actually takes place

seismic waves

elastic rebound

aftershocks

Strong earthquakes are followed by numerous earthquakes of lesser magnitude

foreshocks

ften, but not always, precede major earthquakes by days or, in some cases, several years.

megathrust fault

When convergence entails the subduction of oceanic lithosphere under another plate, the area of contact between the two plates forms an extensive fault zone

fault creep

slow, gradual displacement produce little seismic shaking

seismagraph

seismogram

record made by seismograph

body waves

travel through Earth’s interior P and S waves

surface waves

travel through Earth’s interior

P waves

“push/pull” waves; they momentarily push (compress) and pull (stretch) rocks in the direction the waves are traveling

s waves

“shake” the particles at right angles to their direction of travel.