| Term: | s wave |
| Definition: |
S waves are transverse or shear waves, which means that the ground is displaced perpendicularly to the direction of propagation. In the case of horizontally polarized S waves, the ground moves alternately to one side and then the other. S waves can travel only through solids, as fluids (liquids and gases) do not support shear stresses. Their speed is about 60% of that of P waves in a given material. S waves are sometimes called secondary waves, and are several times larger in amplitude than P waves for earthquake sources. |