Geotechnical and groundwater geophysics

Because of a change in emphasis from power plant siting to process and facility monitoring and certification of existing structures (dams, pipelines, etc.), geotechnical and groundwater geophysics quite is healthy after some lean years following the demise of nuclear energy construction projects. The orders-of-magnitude jump in the computational capability of geophysicists working in these fields has overshadowed advances in instrumentation (e.g., digital enhancement seismographs), field methods (e.g., cross-borehole EM), and interpretive procedures. Powerful, affordable microcomputers have enabled expansion into applications demanding finer resolution and quicker turnaround of results. As a result, shallow seismic reflection, seismic and electromagnetic geotomography, and the complementary use of surface and borehole electrical resistivity and seismic data will soon be common if not dominant methods in geotechnical and groundwater investigations. Future trends point to increased emphasis on environmental and economic issues (e.g., toxic wastes or the stability of underground petroleum storage facilities), cross-fertilization with petroleum reservoir engineering (process monitoring and detailed reservoir description), and greater involvement of computers in the planning, data acquisition, and interpretive phases of our projects. As computers take over more of the data collection-processing-interpretation sequence, one of the greatest challenges facing us will be to define the proper role of humans and to use the new technology wisely.