What is the type of seismic wave that moves the ground up and down or side to side?

The type of seismic wave that moves the ground up and down or side to side is known as S Waves, or secondary waves. These waves are a type of shear wave, which means they involve the motion of the ground perpendicular to the direction of wave travel. This characteristic results in the ground experiencing vertical and horizontal movements, which can be quite damaging during an earthquake.

S Waves cannot travel through fluids, which is why they are only observed in solid materials. Unlike P Waves, which are compressional and arrive first at seismic stations, S Waves arrive later and are typically responsible for the most violent shaking associated with seismic activity. They provide critical information about the earth's interior structure and are key to understanding seismic events.

The other options represent different types of seismic waves: P Waves are compressional waves that move through solids and fluids, Body Waves include both P and S Waves, and Surface Waves travel along the Earth's surface with a rolling or swaying motion. Understanding the distinct characteristics of these wave types helps in the study of earthquakes and the behavior of seismic activity.