Final answer:
Earthquake energy travels through seismic waves, with compressional or P-waves traveling through both solids and liquids and shear or S-waves through solids only. P-waves compress and expand the ground whereas S-waves and surface waves can cause substantial shaking and damage upon reaching the surface.
Step-by-step explanation:
In an earthquake, energy travels in the form of seismic waves which can be categorized mainly into two types: compressional or P-waves and shear or S-waves. The waves that can travel through both solids and liquids are the P-waves, which can compress and expand the ground like an accordion. Conversely, S-waves cannot travel through liquids and only move through solids, potentially causing violent shaking of structures upon reaching the surface. Surface waves, which are another type of seismic wave, can travel slowly within the surface and are responsible for the dramatic ground movements observable during earthquakes.
Understanding the behavior of these waves is critical because it helps geologists and seismologists predict the impact of earthquakes on different materials and structures, and also aids in the investigation of Earth's inner structure. For example, the absence of S-waves in certain areas provides evidence that parts of Earth's interior are liquid, since S-waves cannot be supported by a liquid medium.