Uses of seismic refraction tomography in investigation of groundwater potential in Kaduna millennium city, Kaduna Nigeria

Abstract

Seismic refraction tomography is unique in the sense that shot are taken at every receiver position along the spread. In that way, it becomes possible to conduct both forward and reverse shooting simultaneously along the profile lines. Therefore, every point within the subsurface along the profile lines is probed by both forward and reversed shots. This leads to what one might call the scanning of the subsurface. The data were processed with ReflexW software and a conventional forwardand reversed travel time curve was plotted for each profile lines. Thereafter joint inversion of the travel time picks was carried out. This resulted in the generation of an iterative model, which was used to generate tomographic sections. The result of seismic refraction tomography showed lateral and vertical variation in velocity along most of the profile lines, thereby giving a true image of velocity distribution, both vertically and laterally within the subsurface. Refraction Tomography gave accurate depth and thickness of the overburden along the profile and to delineate aquifer potentialin the basement topography. The aquifer is estimated to be around 45m to 60m along the entire profile line