How do S waves move through the Earth?

S waves, or secondary waves, move through the Earth in a transverse motion, which means they oscillate perpendicular to the direction of wave travel. When S waves pass through the Earth, they cause particles in the material they are moving through to move up and down or side to side, rather than in the direction the wave is traveling. This characteristic of S waves makes them different from P waves (primary waves), which move in a compressional motion, pushing and pulling particles in the same direction as the wave travels.

Understanding that S waves can only propagate through solids and not through liquids is crucial. Therefore, when studying the interior structure of the Earth, the movement of S waves helps seismologists determine where solid and liquid layers exist within the planet. Overall, the transverse motion of S waves plays an essential role in our comprehension of seismic activity and the Earth's internal composition.