SEISMIC REFRACTION MODELING BY COMPUTER

Abstract

A computer program has been developed by the U.S. Bureau of Mines for designing a two‐dimensional, layered earth model as an aid in interpreting seismic refraction field measurements. The program requires input data consisting of shot‐point and geophone locations, refraction traveltimes, and identification of the refraction layer associated with each traveltime. In the program, a first approximation model is generated by a computer adaptation of the delay‐time method, followed by a series of improved approximations that are made by use of a ray‐tracing procedure. The final result of the program is a model designed to minimize the discrepancy between field‐measured traveltimes and computed traveltimes of rays traced through the model. Test applications indicate that the accuracy of interpretation is improved, and that time and effort of the professional interpreter are greatly reduced by use of the computer technique.