Which Comes First P Wave or S Wave

P waves travel fastest and are the first to arrive from the earthquake. In S or shear waves, rock oscillates perpendicular to the direction of wave propagation. In rock, S waves generally travel about 60% the speed of P waves, and the S wave always arrives after the P wave.

Do P waves always arrive first?

Compressional waves are also called P-Waves, (P stands for “primary”) because they are always the first to arrive. They gave us the first jolt last Friday. Shear waves propagate more slowly through the Earth than compressional waves and arrive second, hence their name S- or secondary waves.

Which wave travels faster?

Light waves travel much faster than sound waves. Light waves do not need a medium in which to travel but sound waves do. Explain that unlike sound, light waves travel fastest through a vacuum and air, and slower through other materials such as glass or water.