Introduction to Body Waves

Body waves travel through Earth's interior, transferring energy from earthquakes or volcanic activity. They differ from surface waves, offering key insights into Earth's structure.

There are two main body waves: Primary (P) waves and Secondary (S) waves. P waves are compressional, while S waves are shear waves, each with distinct characteristics.

P waves are the fastest seismic waves, moving through solids, liquids, and gases. They compress and expand the ground, like sound waves through air.

S waves are slower and only travel through solids, moving the ground up and down or side-to-side. This restriction helps scientists infer Earth's liquid outer core.

Body wave velocity depends on the medium's density and elasticity. P waves typically travel at 5-8 km/s, while S waves are slower at 3-5 km/s.

P and S waves are refracted or reflected at layer boundaries within Earth. These transitions reveal the planet's layered structure, including the inner and outer core.

Seismologists use body waves to uncover hidden features like subducted plates, mantle plumes, and even mineral composition, providing a glimpse into Earth's dynamic interior.