Which type of seismic wave has rolling motion, is the slowest, and causes the most damage?

• A. P-waves
• B. S-waves
• C. Surface Waves
• D. Rayleigh Waves

Answer: (C)

Surface waves travel along the ground and are known for causing the strongest shaking at the surface because they have large amplitudes and linger longer as the waves pass. The rolling motion described is typical of Rayleigh waves, a type of surface wave that moves the ground in a rolling, elliptical path. P-waves are the fastest compressional waves and travel first, while S-waves move the ground in shear motion but arrive after P-waves; neither typically produces the same surface-wide, rolling effect or the same level of surface damage. Since surface waves include the rolling-motion behavior and generally produce the most destructive shaking at the surface, they are the best fit.