MAPPING OF SUBSURFACE GEOLOGY WITHIN THE OVERBURDEN FROM SEISMIC VELOCITY USING MULTICHANNEL ANALYSIS OF SURFACE WAVES (MASW): A CASE STUDY OF FUPRE DELTA STATE NIGERIA

ABSTRACT The delineation of subsurface geological structures within the overburden is fundamental for geotechnical, environmental, and engineering applications. The Multichannel Analysis of Surface Waves (MASW) technique has emerged as a robust non-invasive geophysical tool for determining shear-wave velocity (Vs) profiles and mapping near-surface stratigraphy. This study applies MASW refraction analysis to map the subsurface geology of the Federal University of Petroleum Resources, Effurun (FUPRE), Delta State, Nigeria. The method involves acquiring surface wave data from multiple geophone channels, processing the dispersion curves, and inverting them to derive the shear-wave velocity models of the subsurface layers. The velocity profiles obtained are interpreted to characterize the lithological sequence within the overburden, delineate the thickness of unconsolidated materials, and infer the depth to competent bedrock. Results from the study are expected to reveal variations in subsurface stiffness, soil compaction, and possible weak zones across the study area. The MASW approach proves efficient in evaluating subsurface conditions for civil engineering design, environmental assessment, and geotechnical site investigation. The findings contribute to improved understanding of the near-surface geological setting within FUPRE and support future campus infrastructure planning.