S-wave
Secondary or shear waves. S waves are body waves that travel slower than P or primary waves. S waves carry energy through the Earth with a shearing motion, moving particles back and forth in a direction perpendicular to the direction of travel of the wave. S waves can travel through all of the solid layers of the Earth, but not through the liquid outer core. In a slinky, shear waves are generated if one end of a stretched slinky is moved sideways quickly.

(Adapted from: Isachson, Y. W., E. Landing, and J. M. Lauber, S-wave Wave in a Slinky.)