High-F Project Southern California Earthquake Center Current contributors (in alphabetical order) Jacobo Bielak, Yifeng Cui, Steven Day, Robert Graves, Thomas Jordan, Philip Maechling, Kim Olsen, Ricardo Taborda

Background and Motivation High-F Project: Background and Motivation 2005−2006: TeraShake 500 m/s, 0.5−1 Hz 2009−2011: W2W and M8 400 m/s, 1−2 Hz 2007−2008: ShakeOut Simulation and Verification 500 m/s, 0.5−1 Hz 2009−2012: Chino Hills Simulation and Validation 200 m/s, 2−4 Hz

High-F Project: A Recurrent Question 2005−2006: TeraShake 500 m/s, 0.5−1 Hz 2009−2011: M8 and W2W 400 m/s, 1−2 Hz How can we best take advantage of our current and future simulation capabilities over the next five years? 2007−2008: ShakeOut Simulation and Verification 500 m/s, 0.5−1 Hz 2009−2011: ShakeOut Simulation and Validation 200 m/s, 2−4 Hz

Deterministic Physics-Based Earthquake Simulations High-F Project: Unbundled Scientific Kernels Source Inversion Dynamic Rupture Waveform Tomography Source Models Random Params. Off-Fault Plasticity 1D Hybrid Earthquake Simulators Deterministic Physics-Based Earthquake Simulations Velocity Models Full 3D Small-Scale Heterogen. Broadband Attenuation Models CMU Hercules Wave Propagation AWP Graves AWP ODC GPU CyberShake

Deterministic High-Frequency Physics-Based Earthquake High-F Project: The Proposed Strategy Foster closer collaboration towards a common goal of significant scientific value involving multiple SCEC efforts Deterministic High-Frequency Physics-Based Earthquake Simulations Broadband CyberShake

High-F Project High-F Project: Summary Description The High-F project… will integrate various scientific modeling and simulation efforts within SCEC around the objective of reproducing earthquake physics and effects at high frequencies (up to 10 Hz) using deterministic modeling approaches. High-F Project

Source Models valid for 5–10 Hz High-F Project: Source Models valid for 5–10 Hz Kinematic Source Dynamic Rupture Source Inversion Randomness Source Models Earthquake Simulators Pseudo Dynamic Rupture Fault Geometry

Small-Scale Heterogen. High-F Project: Velocity Models valid for 5–10 Hz Velocity Models Attenuation Models Off-Fault Plasticity Full 3D 1D Hybrid Waveform Tomography Small-Scale Heterogen. UCVM Suite Surface Topography CVM-H CVM-S GTL CVM-SI Etree Library

Propagation Simulation High-F Project: Efficient Simulation Engines at 5–10 Hz Visualization XSEDE INCITE GPU CPU Wave Propagation Simulation CMU Hercules AWP Graves AWP ODC

High-F Project: Objectives Produce realistic high-frequency physics-based simulations up to 10 Hz that are comparable to observations from historical earthquakes in Southern California. Incorporate the spatial variability and heterogeneity of the fault geometry and the rupture dynamics into source models that can be used in simulations. Incorporate the fine-scale material heterogeneities that are characteristic of soft- soil structures in sedimentary basins and near-surface deposits in the simulations. Use appropriate goodness-of-fit metrics to investigate the consistency of deterministic and stochastic simulations and their ability to reproduce observed seismograms. Improve SCEC’s framework for a physics-based approach to seismic hazard analysis by developing and advancing the analytical methods and computational applications used in earthquake system science. Engage SCEC (and CME) in a multi-scale interdisciplinary effort to analyze and compare simulation results and data.

Selection of main target event High-F Project: Plan Details High-F Project Plan Phase I: Spark Phase II: Challenges Phase III: Validation Phase IV: Integration Phase V: Beyond Year 1 5 Hz Selection of main target event Selection of alternative target event(s) Definition of initial conditions for Phase II Preparation of discrete representation of models

Source Improvement Challenge Velocity Model Improvement Challenge High-F Project: Plan Details High-F Project Plan Phase I: Spark Phase II: Challenges Phase III: Validation Phase IV: Integration Phase V: Beyond Years 1−2 5 Hz Source Improvement Challenge Velocity Model Improvement Challenge Wave Propagation Improvement Challenge

Incorporate new developments into the simulation engines High-F Project: Plan Details High-F Project Plan Phase I: Spark Phase II: Challenges Phase III: Validation Phase IV: Integration Phase V: Beyond Years 2−3 5−10 Hz Incorporate new developments into the simulation engines Further test improved simulation capabilities Upgrade velocity and source models for simulations Upgrade simulation sets using the improved alternatives Recursive feedback for ongoing challenges

High-F Project: Plan Details Phase I: Spark Phase II: Challenges Phase III: Validation Phase IV: Integration Phase V: Beyond Years 3−4 10 Hz High-F simulation groups capable of 10-Hz simulations will integrate appropriate improved source representations, anelastic models, and wave propagation methods to run 10-Hz deterministic simulations for selected validation events. High-F researchers will run simulations of the target event(s) using selected models and alternatives at a maximum frequency of 10 Hz. High-F researchers will compare and analyze simulation results using observational data and stochastic methods.

High-F Project: Plan Details Phase I: Spark Phase II: Challenges Phase III: Validation Phase IV: Integration Phase V: Beyond Year 5 10 Hz High-F researchers will use the newly developed simulation knowledge and tools to produce a suite of real/scenario earthquake simulations at a maximum frequency equal to 10 Hz.

Phase I: High-F Spark (Year 1) High-F Project: Phase I Reviewed High-F Project Plan Transition Phase I: High-F Spark (Year 1) Identification of current related efforts that can be used and channeled in a coor-dinated manner towards High-F Selection of main and alternative target events Selection of simulation domain and construction of discrete version of velocity models Selection of initial-agreed conditions for Phase II, and evaluation and verification and validation mea-sures to be used Part of today’s discussion (?) Next 4 months Following 4 months

Reconvene at SSA next year? High-F Project: Phase II Reviewed High-F Project Plan Source Models Improvement Challenge Velocity Models Improvement Challenge Wave Propagation Improvement Challenge Phase II: High-F Improvement Challenges (Year 1−2, 5 Hz) Fixed: Target Event Material Model (?) Simulator (?) Agreed: Initial model Initial Stresses (?) Geometry (?) Evaluation Measures Fixed: Target Event Source Model Simulator Agreed: Initial models Evaluation Measures Fixed: Target Event Source Model Velocity Model Agreed: Verification Measures Validation Measures Performance Measures Reconvene at SSA next year?

Mainly Computational Framework Oriented High-F Project: Support and Funding CME Group SI2 Mainly Computational Framework Oriented ? Will need to secure additional funding that is earth science and engineering oriented

High-F Project Southern California Earthquake Center Current contributors (in alphabetical order) Jacobo Bielak, Yifeng Cui, Steven Day, Robert Graves, Thomas Jordan, Philip Maechling, Kim Olsen, Ricardo Taborda