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: -P waves, or Primary waves, are the first waves to arrive at a seismograph.

Detailed explanation-3: -S waves are called secondary waves because they always arrive after P waves at seismic recording stations. Unlike P waves, S waves can travel only through solid materials. After both P and S waves have moved through the body of Earth, they are followed by surface waves, which travel along Earth’s surface.

Detailed explanation-4: -P waves travel the fastest, so they arrive first. S waves, which travel at about half the speed of P waves, arrive later. A seismic station close to the earthquake records P waves and S waves in quick succession.

Detailed explanation-5: -The first wave which reaches the seismograph and which is the fastest is the P wave. The S wave is a bit faster than the surface wave and it reaches the seismograph after the P wave. The last wave to arrive is the surface wave.