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: -Because P waves are the fastest seismic waves, they will usually be the first ones that your seismograph records. The next set of seismic waves on your seismogram will be the S waves. These are usually bigger than the P waves.

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: -Velocity of Body Waves P-waves will always travel faster than S-waves due to the way they deform the material they are traveling through and the restoring forces of that material. Its also important to understand that S-waves can’t travel through liquids.

Detailed explanation-5: -In air, P waves take the form of sound waves and therefore move at the speed of sound, 330m/s at sea level. Some people even report hearing an earthquake (due to the higher frequency P waves vibrating or rustling objects) before they feel the S waves’ arrival.