Electronic Supplement to
Seismic Site Characterization of an Urban Sedimentary Basin, Livermore Valley, California: Site Response, Basin-Edge-Induced Surface Waves, and 3D Simulations

by Stephen Hartzell, Alena L. Leeds, Leonardo Ramirez-Guzman, James P. Allen, and Robert G. Schmitt

This supplementary material shows the comparison of 5% damped acceleration response spectra for data and synthetics.

To investigate the origins of basin-edge-induced surface waves and our ability to predict the ground-motion amplitudes in the Livermore Valley, California, we model two events using a previously verified 3D octree-based finite-element solver (Tu et al., 2006; Bielak et al., 2010) capable of modeling topography. The velocity model we use is the U.S. Geological Survey Bay Area Velocity Model v.08.3.0 (see Data and Resources), with modifications discussed in the main article. In addition, we use the Qs attenuation model from Hartzell et al. (2006). The velocity model’s topography is refined using the 1-arcsec U.S. Geological Survey digital elevation model of the region (see Data and Resources). We approximate the topography in the finite-element simulations with cubed elements and a staircase free surface (Pitarka and Irikura, 1996; Koketsu et al., 2004). The numerical computations use at least 12 points per wavelength to avoid inaccuracies of the linear elements employed in the simulations. In the present implementation of the finite-element solver, attenuation is included by Rayleigh damping. We calculate the ground motion to an upper frequency limit of 2 Hz for two sources, one on the Hayward fault outside the Livermore Valley and another from the San Ramon swarm on the northern end of the valley. Their source parameters are given in Table 1 of the main article. See Figure 19 of the main article for the source locations.

Figures

Figure S1a–e, f–j, k–o, p–t, u–y, and z–cc. Comparison of 5% damped acceleration response spectra for data (solid traces) and synthetics (dashed traces) for an Mw 2.92 event on the Hayward fault. Spectra are plotted from 0.5 to 5.0 s.

Figure S2a–e, f–j, k–o, p–t, u–y, z–dd, and ee. Comparison of 5% damped acceleration response spectra for data (solid traces) and synthetics (dashed traces) for an Mw 3.32 event from the San Ramon swarm. Spectra are plotted from 0.5 to 5.0 s.

Data and Resources

The U.S. Geological Survey Bay Area Velocity Model v.08.3.0 is available online at http://earthquake.usgs.gov/data/3dgeologic (last accessed September 2015). The digital elevation model is available online at http://seamless.usgs.gov/ (last accessed September 2015).

References

Bielak, J., R. W. Graves, K. B. Olsen, R. Taborda, L. Ramirez-Guzman, S. M. Day, G. P. Ely, D. Roten, T. H. Jordan, P. J. Maechling, et al. (2010). The ShakeOut earthquake scenario: Verification of three simulation sets, Geophys. J. Int. 180, no. 1, 375–404.

Hartzell, S., S. Harmsen, R. A. Williams, D. Carver, A. Frankel, G. Choy, P.-C. Liu, R. C. Jachens, T. M. Brocher, and C. M. Wentworth (2006). Modeling and validation of a 3D velocity structure for the Santa Clara Valley, California, for seismic-wave simulations, Bull. Seismol. Soc. Am. 96, 1851–1881.

Koketsu, K., H. Fujiwara, and Y. Ikegami (2004). Finite-element simulation of seismic ground motion with a voxel mesh, Pure Appl. Geophys. 161, 2183–2198.

Pitarka, A., and K. Irikura (1996). Modeling 3D surface topography by finite-difference method: Kobe-JMA station site, Japan, case study, Geophys. Res. Lett. 23, no. 20, 2729–2732.

Tu, T., H. Yu, L. Ramirez-Guzman, J. Bielak, O. Ghattas, K. L. Ma, and D. O’Hallaron (2006). From mesh generation to scientific visualization: An end-to-end approach to parallel supercomputing, Proc. of the 2006 ACM/IEEE Conf. on Supercomputing, Tampa, Florida, 11–17 November 2006.

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