Cross-hole seismic scanning and tomography

摘要: Cross‐hole seismic scanning involves recording seismograms with a source in one borehole and detectors another. Detailed coverage of the rock section between holes is achieved when many depth positions along boreholes are occupied by detectors. Because measurements made beneath strongly dissipative overburden weathering zone, high‐frequency short‐wavelength waves capable resolving small features can be used most types. Although reflections may exist cross‐hole seismograms, focus on transmission events, i.e., direct P or S arrivals which traverse holes. Traveltimes amplitudes events inverted to create maps properties representative geologic cross‐section boreholes. The inversion done using computer‐assisted tomographic (CAT) imaging techniques similar concept those diagnostic medicine, but adapted problem.