Seismic waves are categorized into three main types based on their motion and propagation:

Primary waves (P-waves): These are the fastest seismic waves and travel through both solids and liquids. P-waves cause particles to move in the same direction as the wave’s propagation, resulting in a back-and-forth compressional motion. They are responsible for the initial, less intense shaking during an earthquake.

Secondary waves (S-waves): S-waves are slower than P-waves and only travel through solids. They cause particles to move perpendicular to the direction of wave propagation, producing a side-to-side shearing motion. S-waves are responsible for the more intense shaking felt during an earthquake.

Surface waves: These waves travel along the Earth’s surface and are slower than both P-waves and S-waves. Surface waves are responsible for the most damaging and prolonged shaking during an earthquake. There are two types of surface waves:

• Love waves: These cause horizontal shearing motion in a horizontal plane perpendicular to the direction of propagation.
• Rayleigh waves: These produce an elliptical, rolling motion in the vertical plane parallel to the direction of propagation, causing the ground to move in an elliptical path.

These seismic waves play a crucial role in our understanding of earthquakes and the Earth’s internal structure.