As a seismologist with extensive experience in the study of seismic waves, I can provide you with an accurate description of the propagation of S-waves. S-waves, also known as shear or secondary waves, travel through the Earth's interior by causing particles to move transverse to the direction of the wave's propagation. This means that the ground motion caused by S-waves is perpendicular to the path that the wave is taking as it moves through the Earth. Unlike P-waves, which can travel through both solids and liquids and are the first to be detected by seismographs, S-waves can only travel through solids. This is why they arrive after P-waves at seismic stations, and they are also slower than P-waves. read more >>

P-waves shake the ground in the direction they are propagating, while S-waves shake perpendicularly or transverse to the direction of propagation (i.e. they displace material at right angles to their path). The P-wave is the first to arrive at a location, as it is the fastest.read more >>