← Back to Sessions

Simulation-based Scenario Shakemaps for Earthquakes on the Seattle, Tacoma, and Southern Whidbey Island Faults, Washington, U.S.A.

Description: 

We present a new suite of simulation-based scenario ShakeMaps that characterize ground shaking from large-magnitude (M_w6.5-7.5) earthquakes on the Seattle, Tacoma, and southern Whidbey Island faults. These maps are developed using results from recent 3-D wave propagation simulations (Stone et al., 2022, 2023, 2025) that incorporate realistic rupture geometries, variable slip distributions, and a regional 3-D seismic velocity model with shallow soils. Broadband ground motions are estimated by combining the low-frequency (< 1 Hz) deterministic seismograms from these studies with high-frequency (1-10 Hz) stochastic seismograms. Our ShakeMaps represent median ground shaking estimates derived from multiple rupture scenarios with varying source parameters on each fault. To extend ShakeMap coverage beyond the simulation domain (i.e., into eastern Washington, northern Oregon, and southwestern British Columbia), we scale GMM-based ground motion estimates using amplification patterns observed in the simulations. These new ShakeMaps reveal the substantial influence of deep basin structure and seismic wave radiation patterns on shaking intensity, underscoring the importance of considering source and structural complexity in regional hazard assessments for the Pacific Northwest.

Session: Advancing Seismic Hazard and Risk Assessment through Multi-Disciplinary Approaches [Poster]

Type: Poster

Date: 4/15/2026

Presentation Time: 08:00 AM (local time)

Presenting Author: Ian Stone

Student Presenter: No

Invited Presentation: 

Poster Number: 48

Authors