What is the primary movement of S-waves in the Earth?

S-waves, or shear waves, primarily move through the Earth by shearing or shaking the material they pass through. This type of wave causes particles in the material to move perpendicular to the direction of the wave's travel. As the wave moves, it creates a side-to-side motion, which is distinct from the compressional movement of P-waves (primary waves). S-waves cannot travel through liquids, which is why they provide important information about the Earth's interior structure, indicating the presence of a liquid outer core since they do not reach the opposite side of the Earth when an earthquake occurs. The shear movement is responsible for the type of damage often seen during earthquakes, as it can lead to significant ground shaking and structural failure.

Other movements described in the options are inaccurate interpretations of S-wave behavior. Compressional movements are characteristic of P-waves, while sound waves refer to vibrations transmitted through a medium, not specifically tied to the primary actions of S-waves. Heating up surrounding materials is not a function of wave movement but rather of energy transfer processes that do not pertain to shear waves directly.