Further Reading / Supplemental Links
Vocabulary
amplitude The height of a wave from a center line to the top of the crest (or to the bottom
of the trough.
body waves A type of seismic wave that travels through the body of a planet. The two
types are primary waves and secondary waves.
crest The highest point of a wave.
earthquake Ground shaking caused by the release of energy stored in rocks.
elastic rebound theory The theory of how earthquakes are generated. Elastic rebound
theory states that stresses cause strain to build up in rocks until they can no longer
bend elastically and they break, causing an earthquake.
epicenter The point on the earth’s surface that lies above an earthquake’s focus.
focus The point where rocks rupture during an earthquake.
Love waves These surface waves have a side-to-side motion, much like a slithering snake.
primary waves (P-waves) P-waves are body waves that are the first to arrive at a seis-
mometer because they are the fastest. P-waves are longitudinal waves that travel
through solids, liquids, and gases.
Rayleigh waves These surface waves have a rolling motion.
secondary waves (S-waves) S-waves are body waves that are the second to arrive at a
seismometer. S-waves are transverse waves that can only move through solids.
seismic wave Seismic waves transport the energy released during an earthquake. The two
main types are body waves and surface waves.