Travel times of longitudinal waves from surface foci

Tables and graphs for travel times of seismic waves propagated through the earth are based on earthquake records. This requires accurate knowledge of the longitude and latitude of the corresponding epicenters, focal depths, and origin times. It is highly desirable to compare the resulting travel time curves and tables with results derived from experiments in which all four fundamental quantities are accurately known from independent data.(1) Seismologists are indebted to scientists and organizations for measurements of records and other corresponding information from which accurate travel times of longitudinal waves originating at known surface sources in the Pacific area could be found.