Simulation-based scenario ShakeMaps for large magnitude (Mw6.5+) crustal earthquakes on the Seattle, Tacoma, and southern Whidbey Island faults, Washington, USA (ver. 1.1, June 2026)

This dataset consists of 3-component acceleration timeseries that describe ground shaking from simulated Mw6.5+ earthquakes on the Seattle, Tacoma, and southern Whidbey Island faults in Washington State. These were produced in support of the development of simulation-based scenario ShakeMaps, as described in Stone et al. (2026). Individual scenarios span a variety of different source parameters (hypocenter location, slip distribution, magnitude, dip direction). These were run within a regional-scale model domain with 0-1Hz resolution that covers most of northwest Washington. These low-frequency seismograms were amended with high-frequency (1-10Hz) stochastic seismograms to produce the broadband timeseries. Timeseries were produced on a regular grid of stations spaced at 1km. Timeseries data are saved in HDF5 format. Please refer to the publication Stone et al. (2026) (as well as Stone et al. (2025)) for additional technical details on the simulations and a corresponding analysis of the results. This data release contains the timeseries data from 60 individual simulations, the corresponding pseudo-spectral accelerations, source files, a Jupyter Notebook with an example of how to open and manipulate the data, and a document describing data formatting. Version 1.1 of this dataset was published in June 2026. Relative to the original data release, the timeseries and spectral acceleration data were corrected to account for linear and nonlinear site response, which primarily affects estimates at soft-soil sites; additionally, T=0.6s period values were added to the spectral acceleration files. For inquiries about the old version of the dataset, please contact Ian Stone at istone@usgs.gov.

First release: January 2026
Revised: June 2026 (ver. 1.1)