The three types of seismic waves produced by an earthquake are primary, secondary, and

A. surface. B. sedimentary. C. elastic. D. atmospheric.

There are three types of seismic waves. These are classified on the basis of their penetration in the earth's surface and their arrival to seismographs. First are primary waves, which arrive first and penetrate the deepest. Then are the secondary waves, which penetrate less and arrive after primary waves. Finally are the surface waves, which do not penetrate the earth's surface and arrive the latest.