Surface Waves

Surface Waves
Travelling only through the crust, surface waves are of a lower frequency than body waves, and are easily distinguished on a seismogram as a result. Though they arrive after body waves, it is surface waves that are almost entirely responsible for the damage and destruction associated with earthquakes. This damage and the strength of the surface waves are reduced in deeper earthquakes.








Love (L) Waves
The first kind of surface wave is called a Love wave. Although considerably slower than body waves it's the fastest surface wave and moves the ground from side-to-side. Confined to the surface of the crust, Love waves produce entirely horizontal motion. Although they travel slowly from the seismic source, they are very destructive. It is these waves that are most often responsible for causing buildings to collapse during an earthquake.








Rayleigh (R) Waves
Rayleigh waves are the slowest of all the seismic wave types and in some ways the most complicated. A Rayleigh wave rolls along the ground just like a wave rolls across a lake or an ocean. Because it rolls, it moves the ground up and down, and side-to-side in the same direction that the wave is moving. Most of the shaking felt from an earthquake is due to the Rayleigh wave, which can be much larger than the other waves.