Acceleration Response Spectra

for Full Rupture CSZ Earthquake

This web based tool calculates the deterministic acceleration response spectra for full rupture CSZ (Cascadia Subduction Zone) earthquake for any site in Oregon. The tool uses the methods and assumptions adopted by USGS in considering CSZ in generating the 2014 seismic hazard maps.

The parameters for calculating the acceleration response spectra include the site latitude and longitude, expressed in decimal degrees. The parameter Vs30 describess the average shear wave velocity between 0m and 30m depth, which describes the site soil conditions. As reference, the NEHRP (National Earthquake Hazard Reduction) site classification has been characterized in the past as soil B, C and D with Vs30 values corresponding to 760m/s, 560m/s and 270m/s respectively.

Input should be restricted to coordinates within the state of Oregon and Vs30 values between 200m/s and 1500m/s. By clicking the submit button, the tool outputs a simple text file that can be locally saved and imported into any spreadsheet to plot the spectra. The file contains two columns, the period (seconds) and the spectral acceleration (g).

Note: expect output to take 5 to 10 seconds

This tool was created based on results from research on the effects of Cascadia Subduction Zone (CSZ) on the response of bridges conducted by Portland State University with support funding from the Oregon Department of Transportation. The research team was led by Dr. Peter Dusicka and this tool is the result of work from research assistants Ramiro Bazaez, Zakary Hoyt and Mario Zavalas.