Earthquake Ground Shaking Levels for the Wasatch Front

Salt Lake County – 2003 IBC S1, 1 Second Spectral Response Acceleration Map.

Salt Lake County - 2003 IBC S1, 1 Second Spectral Response Acceleration Map.

2003 International Building Code, 0.2 and 1 second spectral response acceleration maps

The Utah Seismic Safety Commission compiled a series of eight maps showing 0.2 and 1 second spectral response acceleration contours for Weber, Davis, Salt Lake, and Utah Counties.

These maps were created by the Utah Geological Survey (UGS) using the gridded data from the 2003 International Building Code (IBC) Seismic Design Parameters CD-ROM, prepared by the U.S. Geological Survey. The maps show values for an IBC site class B, so adjustments to map values must be made depending on the actual site class as outlined in the IBC.

Generalized site class maps for Salt Lake Valley and the Wasatch Front are available as UGS Open-File Report 424 (CD) and Report of Investigation 248, respectively, at the Natural Resources Map and Bookstore.

These maps are intended for use by building officials and engineers to illustrate earthquake ground-shaking levels, but are not for use in building design.

The IBC Seismic Design Parameters CD-ROM included with the IBC (available from International Code Council; www.iccsafe.org) should be used for design.