An S wave, also known as a shear wave, is a type of seismic body wave that moves through the Earth's interior. It is characterized by its side-to-side motion, which is perpendicular to the direction of the wave's travel. Unlike P waves, which can travel through both solids and liquids, S waves can only propagate through solids. This is because they require the particles in the medium to move parallel to the direction of the wave's motion, which is not possible in liquids. S waves are generally slower than P waves and are not the first waves to be detected by seismographs during an earthquake. The absence of S waves in a seismogram can indicate that the earthquake's focus is in a liquid layer, such as the outer core of the Earth. read more >>

An S wave, or shear wave, is a seismic body wave that shakes the ground back and forth perpendicular to the direction the wave is moving.read more >>