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Validation of Broadband CyberShake Simulations

Session: Physics-Based Earthquake Rupture Modeling and Strong Motion Simulations [Poster]

Type: Poster

Date: 4/22/2021

Presentation Time: 03:45 PM Pacific

Description: 

The Southern California Earthquake Center (SCEC) has developed the CyberShake platform to implement a physics-based probabilistic seismic hazard analysis (PSHA) approach using 3D wave propagation simulations to calculate seismograms and ground motions from sources defined in regional earthquake rupture forecasts. CyberShake has been used to calculate PSHA models for Southern California, Central California, and the San Francisco Bay Area, and is able to quantify effects such as 3D basin amplification and rupture directivity that are difficult to capture in typical empirical ground motion models.

Recently, CyberShake was integrated with the SCEC Broadband Platform (BBP), enabling deterministic low-frequency (1 Hz) physics-based results from CyberShake to be combined with stochastic high-frequency (1-50 Hz) seismograms generated with the Graves & Pitarka BBP modules, producing broadband seismograms. This enables CyberShake to deliver results at high-frequency regimes not yet accessible to deterministic-only simulations, which are particularly useful to the earthquake engineering community.

To evaluate CyberShake broadband results, we have selected historical earthquakes from the BBP validation suite and performed a series of validation exercises, computing CyberShake broadband results for dozens of recording stations. We describe how CyberShake elements, including velocity model, rupture forecasts, and site response were configured to support BBP validation events. We present comparisons of CyberShake models against recorded data, and propose modifications to CyberShake and the BBP to improve their modeling of ground motions.

Presenting Author: Scott A. Callaghan

Student Presenter: No

Authors