What are Seismic Waves?
Seismic Waves are the waves of energy that are caused by the sudden movement of rocks or explosions within the earth. The energy of these waves travels through the earth. Imagine if you will, a stone being thrown into the middle of the lake. Out from the entry point of the stone, into the lake come ripples. In comparison, the stone being thrown into the lake is like an explosion or movement within the earth. The ripples in the lake would then be like seismic wave that travels through the earth. Of course seismic waves and earthquakes are far more complicated than a stone being thrown into water and ripples flowing through. A seismic wave has many components within its waves and it travels differently through many parts of the earth. Components of a Seismic Wave There are many different types of seismic waves, but all of these seismic waves are there are basically two types. Body Waves: Compressional of P waves (P for primary) Traverse or S waves (S for secondary or shear) Surface Waves
Seismic waves are what you feel the ground doing in an earthquake. When the fault ruptures, it sends vibrations out from the fault. These vibrations are somewhat like the waves radiating from a rock thrown into a pond. There are many types of seismic waves, most notably p-waves and s-waves. P-waves are pressure waves moving through the earth, compressing and expanding the ground as they pass by. S-waves move the ground form side to side. Also, there are surface waves know as Love waves and Rayleigh waves. See Types of Seismic Waves in Section II for more information.
