Seismologists, who study earthquakes and the propagation of waves through the Earth, have determined that P-waves travel faster than S-waves. This is due to the fact that P-waves are a type of compression wave that can move through solids, liquids, and gases, applying a force in the direction of their propagation. On the other hand, S-waves, or shear waves, can only move through solids and cause particles to move perpendicular to the direction of the wave's travel. In general, P-waves travel about 60% faster than S-waves on average. This difference in speed is one of the reasons why seismographs can provide early warnings for earthquakes; when a seismogram detects P-waves before S-waves, it indicates that an earthquake is occurring, and the time delay between the two can give an estimate of how far away the earthquake's epicenter is. read more >>

P-waves and S-waves are body waves that propagate through the planet. P-waves travel 60% faster than S-waves on average, because the interior of the Earth does not react the same way to both of them. P-waves are compression waves that apply a force in the direction of propagation.read more >>