Site-specific strong ground motion estimates for the Salt Lake Valley (MP 93-9)

By: I. G. Wong and W. J. Silva

The high level of seismic hazard in Salt Lake Valley from potential large earthquakes on the Wasatch fault zone has long been recognized. Of obvious importance to hazard mitigation is the prediction of the near-field strong ground shaking that will be generated by such earthquakes. Estimates of strong ground motions in Salt Lake Valley that incorporate the site-specific effects of the shallow subsurface geology and details of the earthquake rupture process, however, have not been available to date. Such estimates are especially important because of the potentially significant effects on ground motions from the alluvial deposits which underlie most of Salt Lake Valley.

In this study, we have performed such a site-specific characterization of potential strong ground motions in the Salt Lake Valley based upon a methodology that combines aspects of finite earthquake source modeling with the Band-Limited-White-Noise ground motion model, random vibration theory and an equivalent-linear soil response approach. The objective was to assess the strong ground motions that could be generated assuming a moment magnitude (Mw) 7.0 earthquake occurring on the Salt Lake City segment of the Wasatch fault.

Other Information:
Published: 1993
Pages: 34 p.
Location: Salt Lake County
Media Type: Paper Publication