High-resolution shear-wave reflection profiling to image offset in unconsolidated near-surface sediments
Institution: | University of Kansas |
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Department: | Geology |
Degree: | MS |
Year: | 2014 |
Keywords: | Geophysics |
Record ID: | 2025418 |
Full text PDF: | http://hdl.handle.net/1808/14561 |
S-wave reflection profiling has many theoretical advantages, when compared to P-wave profiling, such as high-resolution potential, greater sensitivities to lithologic changes and insensitivity to the water table and pore fluids, and could be particularly useful in near-surface settings. However, S-wave surveys can be plagued by processing pitfalls unique to near-surface studies such as interference of Love waves with reflections, and the stacking of Love waves as coherent noise, leading to possible misinterpretations of the subsurface. Two lines of S-wave data are processed and used to locate previously unknown faults in Quaternary sediments in a region where earthquake activity poses a threat to surface structures. This study provides clear examples of processing pitfalls such as Love waves with hyperbolic appearances on shot gathers, and a CMP section with coherent noise that is easily misinterpreted as reflections. This study demonstrates pros and cons of using SH reflection data in the near surface.