What material can S-waves travel through and how fast are they? Describe an S-wave's motion.

These waves are of a higher frequency than surface waves. The first kind of body wave is the P wave or primary wave. This is the fastest kind of seismic wave, and, consequently, the first to 'arrive' at a seismic station. The P wave can move through solid rock and fluids, like water or the liquid layers of the earth.

The Earth's molten core can only be traveled through by compressional waves. P-waves travel fastest, at speeds between 4-8 km/sec (14,000-28,000 km/h) in the Earth's crust. S-waves travel more slowly, usually at 2.5-4 km/sec (9,000-14,000 km/h). Sound waves are usually called P-waves and are heard but not often felt.