Unformatted text preview: • Generally determine velocity from first arrival time of wave after impact. • Compression waves: particle motion parallel to propagation of wave (fastest) • Shear waves: particle motion perpendicular to propagation of wave (slower) • Rayleigh wave: surface wave, particle motion elliptical (slowest) • Waves refract through layers at depth. Refracted waves obey Snell's law-refraction angle inversely proportional to wave speed. If deep layer is faster, then refracted wave may arrive before direct wave- defines depth to layer. May help define water table depth and depth to rock. • Typical wave speeds:...
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- Fall '08
- Light, Snell's Law, refractive index