Propagation and resonance of SH waves in the Salt Lake Valley, Utah

The Salt Lake Valley is an alluvium valley where seismic amplification measured at some sites can exceed a factor of 10 relative to hard-rock sites adjacent to the basin. Finite-difference synthetic seismograms were used to successfully characterize key parameters controlling low-frequency SH-wave amplification in the Salt Lake Valley. The Quaternary sediments tend to increase the coda duration, while the semi-consolidated Tertiary sediments act as a wave guide to trap the low-frequency seismic energy. It is also found that the basin can cast a seismic shadow over adjacent bedrock sites, inhibiting seismic wave propagation to sites adjacent to the basin. -from Authors