An explosion only generates compression waves, which are longitudinal waves, like sound, where the particle motion is along the direction of motion (and back ag

An explosion only generates compression waves, which are longitudinal waves, like sound, where the particle motion is along the direction of motion (and back again). For earthquakes, these are known as P-waves, or primary waves, because they travel the fastest and arrive at distant locations first. Explosions do not generate transverse side-to-side motions, which are caused by shear forces. For earthquakes, these are known as S-waves, or secondary waves, because they travel slower and arrive at distant locations later. The S-waves usually cause more damage to buildings in an earthquake, because they last longer and induce a shaking or swaying motion.