1. Body Waves: These travel through the Earth's interior and are divided into two types:
- P-Waves (Primary Waves): Also known as compressional waves, P-waves cause particles in the Earth to vibrate back and forth in the direction the wave is traveling. They are the fastest seismic waves and can travel through solids, liquids, and gases. P-waves are the first to arrive at a seismic station after an earthquake.
- S-Waves (Secondary Waves): Also known as shear waves or transverse waves, S-waves cause particles to vibrate perpendicularly (at right angles) to the direction of wave propagation. S-waves can only travel through solids. Because they are slower than P-waves, they arrive later at a seismic station.
2. Surface Waves: These waves are generated at the boundary between different layers within the Earth's structure. They are the most damaging and disruptive seismic waves near the earthquake's epicenter. Surface waves are divided into two types:
- Love Waves: Love waves cause horizontal ground movement with particles vibrating from side to side perpendicular to the direction of the wave propagation. Love waves travel along the surface and are primarily found near the epicenter.
- Rayleigh Waves: Rayleigh waves produce both vertical and horizontal ground movements with particles moving in an elliptical path. They involve a rolling motion similar to ocean waves and are the slowest of all seismic waves. Rayleigh waves can cause significant ground shaking and damage to structures.
Each seismic wave type generates a unique pattern of ground motion that seismologists analyze to gather information about the earthquake's location, magnitude, and underlying geological structures.
