Seismic Review Questions

1. There are four types of seismic waves: P wave (longitudinal), S wave (transverse), Love wave, and Rayleigh waves.  P and S waves are body waves and go through the Earth.  P waves arrive first.  Love and Rayleigh waves are surface waves, Love waves are transverse and the Rayleigh waves are the most complex and the slowest.

5. Seismic waves are measured using seismometers, which record vibrations in the ground.  One method is to use a drum with a marker attached to a spring-mass system.  To go more old school, the ancient Chinese used a urn with water, that would spill over the mouths of dragons surrounding the urn.  The amount of water indicates the relative strength of th seismic event.  A more modern and advanced seismometer which uses magnets and coils are currently used to measure seismic activity at LIGO.