Travel-time curve

Summary

A travel-time curve is drawn for one type of seismic wave. It gives the time the wave takes to reach a station as a function of the distance from the source. Its slope at each distance is the ray parameter of the arriving ray. Travel-time curves are used to locate earthquakes and, by inversion, to find the speed of waves at each depth. Tables of such curves, such as the Jeffreys–Bullen tables, were among the first quantitative models of the Earth's interior.