Use of passive seismic arrays for seismic hazard assessment

Ground motion prediction is a key part of seismic hazard assessment and relies on a reasonable shear wave velocity model to be useful. Traditional practices of using borehole or slope data for developing a velocity model has either a high cost and impact associated with data collection, as in the borehole case, or does not account for geologic processes or materials that affect shear wave velocities. Both methods produce a velocity model that is mostly inferred over an area of interest rather than measured. Presented herein are case studies that use two different low-cost, low-impact ambient noise surface wave tomography methods for measuring shear wave velocities: eikonal and straight-ray tomography. For each method, a case study is presented along with a discussion of the two methods.