See also Body Waves , S Waves , Surface Waves . Go to What are Seismic Waves by UPSeis to learn more about P waves. This is the time at which the first phase, the P Wave arrives. It marks the beginning of the earthquake on the seismogram. Wave An S Wave is one of two types of body waves.
S stands for secondary or shear.
These waves are similar to light waves. Their velocity is less than that of P Waves. See also Body Waves , P Waves , Surface Waves . Go to What are Seismic Waves by UPSeis to learn more about S waves. Seismology Seismology is the study of earthquakes and waves generated by earthquakes and explosions.