3. What conclusion would you draw if a seismogram from a particular seismic station showed only P waves?

The first waves to be recorded by the seismogram are P-waves since they are the fastest. S-waves come in next and are usually larger than P-waves. The surface waves arrive just after the S-waves. If the earthquake has a shallow focus, the surface waves will be the largest ones recorded. Figure 7.40: These seismograms