THE RECIPROCAL METHOD OF ROUTINE SHALLOW SEISMIC REFRACTION INVESTIGATIONS

Abstract

The Reciprocal Method of shallow seismic refraction investigation provides a simple reliable method of surveys where the absolute depths to important refractors and an analysis of the velocities in the refractors are required in detail. The depth computation is based on an early (1931) concept, termed here the time‐depth, which differs slightly from the delay‐time. The calculation of the individual time‐depths and of the corrected travel times within the refractor require only simple numerical computation. Hence, the method is very suitable for routine survey procedures in which use is made of composite velocity terms for multilayered overburdens. The basis and procedures of the Reciprocal Method are presented together with examples illustrating the application of the method and the technique of velocity analysis.