There are two broad classes of seismic waves: body waves and surface waves.
Body waves travel within the body of Earth.
They include P, or primary, waves and S, or secondary, waves.
P waves cause the ground to compress and expand, that is, to move back and forth, in the direction of travel.
Which seismic waves are compressional due to the fact that they compress and expand rocks in the direction the waves travel?
P-waves are sound waves, it’s just that in seismology we are interested in frequencies that are lower than humans’ range of hearing (the speed of sound in air is about 0.3 km/sec). The vibration caused by P waves is a volume change, alternating from compression to expansion in the direction that the wave is traveling.
Which seismic wave travels most rapidly?
The P in P-waves stands for primary, because these are the fastest seismic waves and are the first to be detected once an earthquake has occurred. P-waves travel through the earth’s interior many times faster than the speed of a jet airplane, taking only a few minutes to travel across the earth.
Which seismic wave can travel through solids?
There are two types of body waves: P-waves travel fastest and through solids, liquids, and gases; S-waves only travel through solids.
Do seismic waves travel from the epicenter?
P-waves travel through solids, liquids, and gases. S-waves only move through solids. Surface waves travel along the ground, outward from an earthquake’s epicenter.