USE OF SEISMIC REFRACTION TO DELINEATE AND CHARACTERIZE FRACTURES IN CARBONATE BEDROCK AND GLACIAL OVERBURDEN OF NORTHWEST OHIO

摘要: Charles Onasch, Advisor Methods were developed to locate and characterize fracture networks within carbonate bedrock glacial overburden of northwest Ohio using seismic data collected in radial grid arrangements. Two study areas chosen isolate the desired targets: a site with less than 1 m for fractures, over 10 fractures. Data Geometrics SmartSeis 24 channel Seismograph hammer as an energy source. Three methods evaluated, each which is based on recognizable phenomena associated propagation across discontinuity: arrival time delays, diffracted waves resulting from wave scatter, amplitude attenuation anomalies. Each these was tested confirmed control surveys done pavement containing several The location orientation traces identified by noting location(s) fractures individual profiles, determined one or more three methods, connecting them locations adjacent profiles. found have dominant trends 094° , 040° 055°, 122° 135°. 082° 030° 045°. These results are similar those Nolan (2000) Dean et al. (1991). overall success used conjunction another has proven be quite useful. However, produced use anomalies appear much robust alleviate bias arrival-time delay diffraction methods. Additionally, arrangement geophones proved show better linear agreement line-to-line then arrangement. subsurface both cost timeefficient, when other geophysical can essential exploration tool.