GEOLOGY

Detailed explanation-1: -P waves travel fastest and are the first to arrive from the earthquake. In S or shear waves, rock oscillates perpendicular to the direction of wave propagation. In rock, S waves generally travel about 60% the speed of P waves, and the S wave always arrives after the P wave.

Detailed explanation-2: -The first kind of body wave is the P wave or primary wave. It’s the fastest kind of seismic wave, and the first to arrive at a seismic station. P waves can move through solid rock and fluids, like water or the liquid layers of the Earth.

Detailed explanation-3: -Generally, p-wave velocity increases with depth and increases with increasing rigidity of a material. Therefore p-waves travel fastest through the solid, iron inner core of Earth.

Detailed explanation-4: -The P wave is designated the primary preliminary wave because it is the first to arrive at a seismic station after an earthquake.