During an earthquake, surface waves are the seismic waves that cause the most damage. Unlike other seismic waves that move deep inside the Earth, surface waves move along just under the surface of the Earth like waves in water.
Surface waves are the slowest seismic waves and are the final waves to hit an area after an earthquake. First, P-waves move through compression through the deep layers of the Earth. P-waves are also carried by air and water, causing them to make a sound when they hit the Earth's surface. They result in minimal damage. The second group of waves is S-waves. They move up and down starting deeper in the Earth, and they cannot travel through air or water. Stronger S-waves do some damage when they reach the surface. Surface waves move in last. Their slow roll just under the surface provides the greatest risk for damage to man-made structures and changes to natural landforms.