GEOLOGY

Detailed explanation-1: -P waves, or primary waves, arrive first while S waves, or secondary waves, arrive second. Both waves cause the ground to shake when an earthquake occurs. S waves cause more intense shaking than P waves and are typically much more destructive.

Detailed explanation-2: -In P or compressional waves, the vibration of the rock is in the direction of propagation. 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.

Detailed explanation-3: -P waves and S waves are alike because they are both types of seismic waves produced by the sharp movement of rocks within the earth. Both P and S waves are body waves, which means that they both travel through the interior of the earth.

Detailed explanation-4: -P waves cause the ground to compress and expand, that is, to move back and forth, in the direction of travel. They are called primary waves because they are the first type of wave to arrive at seismic recording stations. P waves can travel through solids, liquids, and even gases.

Detailed explanation-5: -S waves are more dangerous than P waves because they have greater amplitude and produce vertical and horizontal motion of the ground surface. The slowest waves, surface waves, arrive last. They travel only along the surface of the Earth.