There are generally four types of earthquake waves, known as seismic waves. These waves are generated by the release of energy during an earthquake and travel through the Earth's layers. The four types of seismic waves are:
P-waves (Primary waves): P-waves are the fastest seismic waves and are the first to be recorded by seismographs. They are compression waves that travel through solids, liquids, and gases. P-waves cause particles in the material to move back and forth in the same direction as the wave propagation, similar to a coiling spring. They can travel through the Earth's interior and are the least damaging compared to other waves.
S-waves (Secondary waves): S-waves are slower than P-waves and are the second to arrive at seismographs. They are shear waves that propagate by moving particles perpendicular to the direction of wave travel. S-waves can only travel through solid materials and are responsible for causing the side-to-side shaking motion during an earthquake. They are more destructive than P-waves.
Surface waves: Surface waves are slower than both P-waves and S-waves. These waves travel along the Earth's surface and are responsible for the most significant damage during an earthquake. There are two types of surface waves:
a. Love waves: Love waves cause horizontal shaking of the ground and have a side-to-side motion similar to S-waves. They are slower than S-waves and have a larger amplitude, making them highly destructive.
b. Rayleigh waves: Rayleigh waves cause both vertical and horizontal rolling motion of the ground. They have a circular motion, similar to water ripples, and are slower than Love waves. Rayleigh waves are responsible for the majority of long-period ground shaking during an earthquake.
Each of these seismic waves has different properties, such as speed, motion, and potential for causing damage, which make them useful for studying and understanding earthquakes.