Seismic Hazard Maps for Seattle, Washington, Incorporating 3D Sedimentary Basin Effects, Nonlinear Site Response, and Rupture Directivity

Earthquake Ground Motion and 3D Georgia Basin Amplification in Southwest British Columbia: Deep Juan de Fuca Plate Scenario Earthquakes

“…In the base elastic 3D model, a northeast-trending velocity contrast occurs beneath Greater Vancouver, which is not supported by geological and structural information, but rather results from extrapolation of the 1 km gridded V P model of Ramachandran et al (2006) to the surface. When the base elastic 3D model is used in FD simulations of the Nisqually earthquake, good agreement is obtained between synthetic and empirical waveforms in the Seattle basin region (Molnar et al, 2010), because significant effort had gone into validating the 3D model (Frankel and Stephenson, 2000;Hartzell et al, 2002;Pitarka et al, 2004;Frankel et al, 2007Frankel et al, , 2009). However, synthetic waveforms overpredict Nisqually waveform amplitudes in the Georgia basin region by a factor of 2.1 (Molnar et al, 2010).…”

“…1). The Georgia basin is one in a series of basins spanning from California to south Alaska along the Pacific margin of North America ( England and Bustin, 1998), and is relatively wide and shallow (Tertiary dimensions of 130 by 70 by 5 km) in comparison to basins southward in Seattle (75 by 30 by 8 km; Frankel et al, 2007) and Los Angeles (50 by 30 by 5 km; Magistrale et al, 1996). Properties of the Late Cretaceous and Tertiary sedimentary rocks within the Georgia basin and its basement are known from seismic surveys (e.g., White and Clowes, 1984), particularly seismic tomography results of the 1998 Seismic Hazards Investigations in Puget Sound experiment (Zelt et al, 2001;Ramachandran et al, 2004;Dash et al, 2007).…”

“…Realistic prediction of ground motion in sedimentary basins subject to the threat of future large earthquakes therefore requires 3D modeling. Ultimately, 3D basin effect simulations should be directly incorporated in the generation of probabilistic seismic-hazard maps, as was carried out for Seattle, Washington, by Frankel et al (2007).…”

Ground‐Motion Simulation for the 23 August 2011, Mineral, Virginia, Earthquake Using Physics‐Based and Stochastic Broadband Methods

“…CyberShake uses full 3D wave propagation synthetics to forecast ground motions that will be produced by specific ruptures and that are expected to be more accurate for many sites than commonly used empiricalbased GMPEs. Similar work has been done by Frankel et al (2007) using a 3D velocity model of the Seattle, Washington, area and incorporating nonlinear site response. The Broadband Platform (BBP) is another project by SCEC that is working to generate 0-100 Hz seismograms for historical and scenario earthquakes in California, eastern North America, and Japan based on 1D velocity structure models Maechling et al, 2015).…”

Predicted and Observed Spectral Response from Collocated Shallow, Active- and Passive-Source Vs Data at Five ANSS Sites, Illinois and Indiana, USA

“…The use of Vs in assessing site response in urban seismic hazard investigations is rapidly coming to the forefront of research (e.g., Cramer 2003;Cramer et al 2004;Frankel et al 2007Frankel et al , 2009. Vs is also an important parameter in building codes (ICC 2006) and in design applications by the earthquake engineering community (Kramer 1996).…”