Three urban shear-velocity transects using the refraction microtremor method

These surveys of shallow ground shear velocity provide information that will assist in mitigating earthquake hazards in the Reno, Los Angeles and Las Vegas urban areas, and in responding to a damaging earthquake. This work is a reconnaissance, looking for ``hot spots'' in the seismic shaking hazard. As shallow shear velocity decreases, shaking hazard increases (Borcherdt, et al., 1991). The three transects were completed quickly and economically using the refraction microtremor method of Louie (2001). The results were tested for consistency with physical processes by applying a fractal analysis.