For an earthquake at shallow hypocentral depth, the travel times for the PS and SP phases are the same, though their amplitudes will be different. For earthquakes with deeper hypocentral depths, the PS and SP phases arrive at slightly different times. To better visualize how these waves propagate through the Earth, look at the raypaths plots below. These figures show a cross-section of the Earth, with several raypaths that represent seismic waves leaving the earthquake and propagating to the seismographs. Of course, there are many more raypaths that leave the earthquake hypocenter in all directions.
All seismograms are vertical component of ground motion.
Seismograms are from the MichSeis-OhioSeis network in the Great Lakes region of North America, the epicentral distances to these stations range from 112 to 115 . All seismograms are vertical component of ground motion. Since this EQ is larger than the 99feb22 event, these phases are clearly recorded.