1 / 29

The SCEC Broadband Ground Motion Simulation Platform

The SCEC Broadband Ground Motion Simulation Platform. Paul Somerville, Scott Callaghan, Philip Maechling , Robert Graves, Nancy Collins, Kim Olsen, Walter Imperatori , Megan Jones, Ralph Archuleta, Jan Schmedes , Thomas H. Jordan. Stress transfer. Fault rupture. Surface faulting.

amber
Download Presentation

The SCEC Broadband Ground Motion Simulation Platform

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. The SCEC Broadband Ground Motion Simulation Platform Paul Somerville, Scott Callaghan, Philip Maechling, Robert Graves, Nancy Collins, Kim Olsen, Walter Imperatori, Megan Jones, Ralph Archuleta, Jan Schmedes, Thomas H. Jordan

  2. Stress transfer Fault rupture Surface faulting Landslides Dynamic triggering Liquifaction Fires Slow slip transients Seismic shaking Socioeconomic aftereffects Structural & nonstructural damage to built environment Tectonic loading Stress accumulation Nucleation Seafloor deformation Human casualties Tsunami Origin time Disease 0 year decade minute hour day century decade year month week day Anticipation time Response time ------ Aftershocks ------------------------------------------------------------------- ----- Foreshocks ----- Southern California Earthquake Center • Collaboration of 600+ scientists at 60+ institutions • SCEC conducts earthquake system science • Many physical phenomena involved • Community Modeling Environment (CME) improves computational models

  3. Earthquake Simulations • Scenario earthquake simulations increase understanding of ground motions • Valuable in determining seismic hazard • SCEC performs a variety of large-scale scenario simulations N

  4. Broadband Platform • Collaborative software system • SCEC research groups • CME software development • Computes seismograms from 0-10 Hz • Can be run by scientists or engineers without detailed knowledge of the code details • Open development and user access

  5. http://scec.usc.edu/scecpedia/Broadband_Platform

  6. Features and Attributes • Transparency / Reproducibility • Software is open and downloadable • Software Control • Formal releases with documentation • Version control • Flexibility • Modular architecture • Standardized data formats • Expandability • Designed for easy addition / revision of computational modules

  7. Current Capabilities • Can run historical earthquakes • Validate simulations against observed results • Scenario earthquakes • Ground motions due to potential earthquakes • User supplies earthquake description • User provides list of sites at which to perform simulations • User selects modules to run • Multiple implementations of same functional steps • Compare and contrast codebases

  8. Low Frequency Simulation (< 1 Hz) • Source Description • CFM, ERF • Mw, Dimension, Geometry deterministic Combine into BB, add Site Response Kinematic Rupture Generator • GF Libraries • Site Lists • Velocity Models Standard Rupture Format stochastic High Frequency Simulation (> 1 Hz) Broadband Time Series (0 – 10 Hz) Schematic Workflow

  9. Current Modules URS: Graves, R. W. and A. Pitarka (2010). “Broadband Ground-Motion Simulation Using a Hybrid Approach.” BSSA., 100, 2095-2123, doi: 10.1785/0120100057. SDSU / ETH: Mai, P.M., W. Imperatori, and K.B. Olsen (2010). “Hybrid broadband ground motion simulations: combining long-period deterministic synthetics with high frequency multiple S-to-S back-scattering.” BSSA, 100, 2124-2142, doi: 10.1785/0120080194. UCSB: Schmedes, J., R. J. Archuleta, and D. Lavallée (2010). “Correlation of earthquake source parameters inferred from dynamic rupture simulations.” JGR, 115, B03304, doi:10.1029/2009JB006689.

  10. Rupture Generation • Converts user-provided simple earthquake description into full kinematic rupture description (SRF file) • Optional module (can supply SRF) MAGNITUDE = 6.67 FAULT_LENGTH = 20.01 DLEN = 0.2 FAULT_WIDTH = 25.01 DWID = 0.2 DEPTH_TO_TOP = 5.0 STRIKE = 122 RAKE = 90 DIP = 40 LAT_TOP_CENTER = 34.344 LON_TOP_CENTER = -118.515 HYPO_ALONG_STK = 6.0 HYPO_DOWN_DIP = 19.4 DT = 0.01 SEED = 3092096 CORNER_FREQ = 0.15 Source Description Rupture with slip

  11. Seismogram Generation • High-frequency generation • 1-10 Hz seismograms • Stochastic attributes • Three implementations • Low-frequency generation • Generates 0-1 Hz seismograms • Deterministic, calculated from1-D Green’s functions • Two implementations

  12. Combine into Broadband • Matched filters at 1 Hz • Low-cut for HF • High-cut for LF • Sum to get BB (Seyhan et al., 2011)

  13. Site Effects • Adjusts seismograms based on site specific properties • Current modules Vs30 based Before site response After site response

  14. Optional comparisons • Response spectra • Examine frequency behavior • Can compare against observed or simulated results • Goodness-of-fit • Compares response spectra from ≥3 stations

  15. Data Products Velocity and acceleration seismograms Rupture Plots Station and fault trace maps

  16. Comparison Data Products Goodness-of-fit Spectral response comparison Seismogram comparison

  17. Software Engineering • Modular design • Code integration • Software testing • Formal release

  18. Modular Design • Each module represented by Python class • User chooses which implementation URS SDSU UCSB … User input: URS SDSU UCSB … Construct description Workflow description Execute modules … SDSU UCSB URS Low freq High freq Site response

  19. Example Invocation # ./run_bbp_2G.py Welcome to the SCEC Broadband Platform. Please select the modules you want to run. Do you want to perform a validation run (y/n)? n Do you want to run a rupture generator (y/n)? y Rupture generators: URS (1) UCSB (2) ?1 Using region: Southern California Choose a low frequency module: URS (1) UCSB (2) ?2 Found multiple BBP station list files in the start directory. Please select one: nr_one_stat.stl (1) valid_test_stat.stl (2) nr_five_stat.stl (3) ?3 Choose a high frequency module: ... You can find results in /home/scec-00/scottcal/bband/. . .

  20. Code Integration • Goal to make platform easy to run without detailed code knowledge • Modified codes to read and write common (i.e., standardized) formats • Simplifies addition of future modules

  21. Software Testing • Need to verify platform is installed correctly • Three levels of testing • Checksums to verify data files • Unit testing • Each module checked for correct performance • Acceptance testing • All combinations of modules run to check integration • Very useful in locating problems • Gives users confidence in results

  22. Formal Release • Platform targeted at wide variety of users • Requires extra effort with science codes • Detailed user’s guide • Track system for bugs • Version 11.2.0 released on February 18, 2011 • Official web site http://scec.usc.edu/scecpedia/Broadband_Platform

  23. Current Applications • NGA-West 2 • Footwall / hanging wall simulations • NGA-East • Simulations to help constrain ground motion prediction equations (GMPEs) Zeng et al. 11:45 am today

  24. Future Plans • Reduce software dependencies (e.g. OS, compilers) • Additional modules • New modules • 1D GF calculator • 3D GF calculator • Parallel version • Increase support for varied execution environments • Virtual machines • Cloud

  25. http://scec.usc.edu/scecpedia/Broadband_Platform

  26. Verification and Validation • Similar results verifies multiple complex codes Finite difference (URS) Finite difference (AWP-ODC) Finite element (CMU)

  27. Small-scale simulations • Hundreds of thousands of potential M5+ events in Southern California • Enable individual scientists to run simulations • Compare results from multiple codebases

  28. Schematic

More Related