TEMPLATES FOR FITTING SMOOTH VELOCITY FUNCTIONS TO SEISMIC REFRACTION AND REFLECTION DATA*

Velocity functions can be grouped into families, any One of which results, in seismic pictures differing among themselves only in their scales of time and distance but similar in all other respects. For any one of these families it follows that curves drawn on logarithmic scales of time and distance to represent a particular relationship between seismic quantities will be similar in shape. This leads to the use of templates with logarithmic scales for fitting a smooth velocity function to a set of seismic data. Suitable templates for fitting refraction and reflection data to velocity distributions linear with either depth or vertical time are presented. An insight into the uncertainties involved is obtained with the aid of numerical examples.