The Oklahoma earthquake of April 9, 1952 provided an instrumental study of seismograms throughout the United States. There is good evidence for the existence of crustal layers, and consequently a shallow depth of focus. The normal velocities of P and S obtained were 8.07 and 4.43 km/sec.
This paper is a summary of a Master's thesis in geophysics at the Saint Louis University Institute of Technology. The complete thesis may be consulted in the Institute library.