Using the tool: Select the hazard level (return period). Specify latitude and longitude in decimal degrees in the input boxes or use Google Maps and drag the map marker to the desired site location. Specify the time-averaged shear-wave velocity in the upper 30m (Vs30) in the input box. After submitting the data, the Uniform Hazard Spectrum (UHS) for the selected hazard level will be reported along with near-fault adjustment factors as required by Caltrans Seismic Design Criteria (SDC) V2.1.