GEOLOGY

Detailed explanation-1: -S waves arrive next and cause a structure to vibrate from side to side. They are the most damaging waves, because buildings are more easily damaged from horizontal motion than from vertical motion.

Detailed explanation-2: -Rayleigh waves cause both vertical and horizontal ground motion. These can be the most destructive waves as they roll along lifting and dropping the ground as they pass.

Detailed explanation-3: -An earthquake also causes secondary or shear waves, called S waves. These travel at about half the speed of P waves, but can be much more destructive. S waves move the earth perpendicularly to the direction the wave is traveling.

Detailed explanation-4: -Surface waves are the seismic waves that cause the most damage. Surface waves are named as such because they move along close to the surface of the Earth. Some waves can move side-to-side, causing a twisting action in the ground. These are called Love waves.

Detailed explanation-5: -Of the two types of surface waves, the L-waves are the most destructive. They can literally move the ground beneath a building faster than the building itself can respond, effectively shearing the base off of the rest of the building.