GEOLOGY

Detailed explanation-1: -Different kinds of shaking occur due to passage of different kinds of waves. As the P-waves arrive the ground will move up and down. The S-waves produce waves that both move the ground up and down and back and forth in the direction of wave motion.

Detailed explanation-2: -An earthquake generates seismic waves that pass through the ground. As those waves pass near or underneath your house, it can move from side to side and up and down. The shaking your house experiences depends on how far it is from the fault and the soil under and around it.

Detailed explanation-3: -Rayleigh waves, also called ground roll, travel like ocean waves over the surface of the Earth, moving the ground surface up and down. They cause most of the shaking at the ground surface during an earthquake.

Detailed explanation-4: -The effects from earthquakes include ground shaking, surface faulting, ground failure, and less commonly, tsunamis.

Detailed explanation-5: -Various physical considerations suggest a limit somewhere in the range of 3 to 6 m/sec for near-surface earthquakes. Peak ground velocities observed in the vicinity of nuclear explosions may provide some insight.