Fastest type of Wave. Arrives first at station. The velocity of P waves is controlled by how the material through which wave is traveling responds to compressional and shear forces. The back and forth motion displaces rocks as P waves pass and cause powerlines and fences to snap. Also known as Shear Waves Motion of matter due to S waves -displacement of adjacent rocks in a direction perpendicular to the direction of wave propagation.
S waves are slower than P waves.
They are the second fastest type of wave. They tend to arrive second at the station. The velocity of S waves is controlled by how the material through which wave is traveling responds to shear forces. It also depends on the density of the material. This vibration generates surface waves which travel within the upper few kilometers of the Earth's crust.