Earthquake waves can be classified under two categories:
Body waves are those waves that travel through the earth. They originate at the epicentre of the earthquake and travel through the earth at amazing speeds. There are two types of body waves, namely,
Surface waves are those waves that travel on the surface of the earth. The destruction caused by earthquakes is primarily done by these waves.
S waves - S waves also called secondary waves and shear waves, are the second waves to hit the seismographs. They are transverse waves, which means that the motion is perpendicular to the direction of wave propagation. S waves can only travel through solids, and scientists have successfully mapped the earth’s interior by studying the routes of these waves.
P waves - P waves or Primary waves are the first waves to hit the seismographs when an earthquake strikes. They are longitudinal waves which means that the direction of motion and propagation are the same.
