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SCEC Broadband Platform (BBP)

SCEC BBP Software Developers
Software Repository 
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Distribution Formats
SCEC GitHub source code
Docker Images
Mailing List
Join BBP mailing list for announcements, new releases

User Resources
Issue Reporting
Contact: software@scec.org

Software License


The Southern California Earthquake Center (SCEC) Broadband Platform (BBP) is a collection of open-source scientific software modules that can simulate broadband (0-20+ Hz) ground motions for earthquakes at regional scales, compare simulation results between methods, and validate simulation results against observations.  BBP software modules include kinematic rupture generators, low- and high-frequency seismogram synthesis methods that model the propagation of seismic waves through 1D layered velocity structures, site-effects modules, ground motion intensity measure calculations, and ground motion goodness-of-fit tools. Advanced scientific codes on these topics have been integrated into a software system that provides user-defined, repeatable calculation of ground-motion seismograms, using alternative simulation methods, and software utilities to generate tables, plots, and maps. The BBP has been developed over the last ten years as a collaborative project involving geoscientists, earthquake engineers, including graduate students, researchers and practitioners, and the SCEC research computing group.

Current Release

The current Broadband Platform release v22.4.0 is available on the main branch in the SCEC GitHub repository. This version can be retrieved from GitHub with this command.:
This will retrieve the Broadband Platform source code and associated installation scripts. The BBP software can be compiled and run on recent Linux software distributions using recent GNU compilers. The BBP installation process will retrieve required data libraries used by the Broadband Platform. Installation instructions are provided in the BBP user documentation wiki.

Release Notes

The latest Broadband Platform software v22.4.0 was released in September 2022. Highlights of this release include:
  • Included multi-segment rupture support for GP, SDSU, Irikura 1, Irikura 2, and Song simulation methods. Currently provided multi-segment validation events are Landers, Ridgecrest 19C, and San Simeon.
  • Updated GP low-frequency module (jbsim) to perform time-shifting in the time domain instead of frequency domain. This avoids calculating numerous FFTs and results in a significant processing speedup of 10x and benefits all simulation modules that use the GP low-frequency code. 
  • Modified UCSB simulation method to include support for double corner frequency (DCF)
  • Included FAS validation module that produces FAS Goodness-of-Fitness plots, for a better seismological interpretation of the results. This is in addition to the PSA validation that is the main metric for design in engineering.
  • Added Green's Functions and validation events for the Southern Walker Lane region (Southern Sierra Nevada) of California. Validation events include the 2019 Ridgecrest sequence.
  • Expanded the GP GoF module to include a Vs30 GoF plot (similar to the distance and map GoF plots) that can be used to show GoF bias related to stations' Vs30s.
  • Updated the GP rupture generator to genslip-5.5.2 and the high-frequency code to hb_high_6.0.5.
  • Addition of Continuous Integration


The SCEC Broadband Platform development is supported by the Southern California Earthquake Center which is funded by NSF Cooperative Agreement EAR-1600087 and USGS Cooperative Agreement G17AC00047 and with additional support from Pacific Gas and Electric.

User Resources

Broadband Platform Mailing List
For announcements about new releases: Join the BBP mailing list
Target Broadband Platform Computing Environment
The Broadband Platform is designed to compile and run on recent Linux distributions. The BBP platform uses a large (150GB+) input datasets during standard processing. Simplified versions of the Broadband Platform are available in Docker images to support initial evaluation of the software on multiple computing platforms without requiring administrative privileges on a Linux server.

Developer Resources

Development Version
A development branch of the BBP GitHub repository is used to integrate new BBP features before they are released. This development branch should be considered experimental, and we do not recommend using it for research purposes.
NOTE: BBP Development Version - Experimental Use Only
Retrieve Previous Versions
We recommend using the latest version of the BBP, and not earlier versions. The current version includes method improvements, additional validation events, and bug fixes. However, we provided access to earlier versions of the platform to support reproducibility of previous BBP results, if needed.
The source code for a development version of the Broadband Platform, that uses Python3, is available on a GitHub branch. 
Initial BBP Python3 BBP development release
git clone –depth 1 -b 19.8.0-python3 https://github.com/SCECcode/bbp.git
The last full BBP release was a Python 2 version of the platform. The source code for this version is also available in SCEC BBP GitHub repository.
Last Python2 BBP release version
git clone –depth 1 -b 19.4.0 https://github.com/SCECcode/bbp.git

An earlier version of the BBP released in 2017 is also available in the SCEC GitHub repository. 

2017 BBP release

git clone –depth 1 -b 17.3.0 https://github.com/SCECcode/bbp.git 
Related Repositories
SCEC also manages a GitHub repository which contains scripts for creating Docker images from the BBP software. A full BBP installation requires many GigaBytes of data storage. To keep the BBP Docker image sizes smaller, the BBP Docker images contain a limited number of ground motion simulation methods and a limited number of validation event datasets. The BBP Docker images are distributed because they will run on multiple computer platforms, including Linux, Mac, and Windows, without requiring installation of compilers, and they provide a simple way for users to preview the BBP software. 
BBP Docker GitHub Repository
Users do not need to retrieve the BBP Docker repository to use BBP Docker Images. The BBP Docker repository contains scripts that create the Docker images:
Users that are running Docker on their computer, can retrieve and run a simplified version of BBP from the SCEC DockerHub Repository with this command. Instructions for running this BBP Docker image are available in the BBP Docker user documentation wiki.
docker run -it --ulimit stack=-1 --mount type=bind,source="$(pwd)"/target,destination=/app/target sceccode/bbp_22_5:211210

Supporting Documentation

Online BBP Software Documentation:
Broadband Platform community wiki, with links to BBP software training materials, ares posted on a SCEC wiki at:

Data Products

For each BBP software release, each ground motion simulation method is run for each validation event, and these results are posted online. The complete set of validation results for the current BBP v22.4 release are available at:
Fabio Silva, Philip James Maechling, & Christine Goulet. (2022). SCEC Broadband Platform Release 22.4.0 Validation Data (22.4.0) [Data set]. Zenodo. https://doi.org/10.5281/zenodo.7063074
BBP Part A Validation results compare BBP ground motion simulations results against observed ground motions for well-observed historic earthquakes.
BBP Part B Validation results compare ground motion simulation results to amplitudes predicted by GMPEs.

How to Cite

Body Text
The research described in this article used the SCEC Broadband Platform v22.4.0 software (Maechling, 2015) published under the BSD-3 license.
We would like to acknowledge use of the Broadband Platform software provided by the Southern California Earthquake Center (http://scec.org) which is funded by NSF Cooperative Agreement EAR-1600087 and USGS Cooperative Agreement G17AC00047.
Cite Code As
Fabio Silva, Kevin Milner, & Philip Maechling. (2022). SCECcode/bbp: Broadband Platform Release v22.4.0 (v22.4.0). Zenodo. https://doi.org/10.5281/zenodo.7062972
Primary Reference
Maechling, P. J., F. Silva, S. Callaghan, and T. H. Jordan (2015). SCEC Broadband Platform: System Architecture and Software Implementation, Seismol. Res. Lett., 86, no. 1, https://doi.org/10.1785/0220140125 SCEC Contribution 1981

Acknowledge Methods

Along with citing the Broadband Platform software, researchers should also cite the appropriate publication for any of the ground motion methods models they use in their research. References for specific computational methods included in the Broadband Platform and for the validation procedures developed by the Broadband Platform include:
  • Goulet, C.A., Abrahamson, N.A., Somerville, P.G. and K, E. Wooddell (2015) The SCEC Broadband Platform Validation Exercise: Methodology for Code Validation in the Context of Seismic-Hazard Analyses, Seismol. Res. Lett., 86, no. 1, doi: 10.1785/0220140104 SCEC Contribution 6070
  • Dreger, D. S., Beroza, G.C., Day, S. M., Goulet, C. A., Jordan, T. H., Spudich, P. A., and Stewart, J. P. (2015). Validation of the SCEC Broadband Platform V14.3 Simulation Methods Using Pseudospectral Acceleration Data, Seismol. Res. Lett., 86, no. 1, doi:10.1785/0220140118 SCEC Contribution 1983
  • Anderson, J. G (2015) The Composite Source Model for Broadband Simulations of Strong Ground Motions Seismological Research Letters, January/February 2015, v. 86, p. 68-74, First published on December 17, 2014, doi:10.1785/0220140098 SCEC Contribution 1997
  • Atkinson, G. M., and Assatourians, K. (2015) Implementation and Validation of EXSIM (A Stochastic Finite-Fault Ground-Motion Simulation Algorithm) on the SCEC Broadband Platform Seismological Research Letters, January/February 2015, v. 86, p. 48-60, First published on December 17, 2014, doi:10.1785/0220140097 SCEC Contribution 6067
  • Crempien, J. G. F., and Archuleta, R. J. (2015) UCSB Method for Simulation of Broadband Ground Motion from Kinematic Earthquake Sources Seismological Research Letters, January/February 2015, v. 86, p. 61-67, First published on December 17, 2014, doi:10.1785/0220140103 SCEC Contribution 2085
  • Dreger, D. S., and Jordan, T. H. (2015) Introduction to the Focus Section on Validation of the SCEC Broadband Platform V14.3 Simulation Methods Seismological Research Letters, January/February 2015, v. 86, p. 15-16, doi:10.1785/0220140233 SCEC Contribution 6069
  • Graves, R., and Pitarka, A. (2015) Refinements to the Graves and Pitarka (2010) Broadband Ground-Motion Simulation Method Seismological Research Letters, January/February 2015, v. 86, p. 75-80, First published on December 17, 2014, doi:10.1785/0220140101 SCEC Contribution 1947
  • Olsen, K. B., and Takedatsu, R. (2015) The SDSU Broadband Ground-Motion Generation Module BBtoolbox Version 1.5 Seismological Research Letters, January/February 2015, v. 86, p. 81-88, First published on December 17, 2014, doi:10.1785/0220140102 SCEC Contribution 1985
  • Song, S.G. (2016) Developing a generalized pseudo-dynamic source model of Mw 6.5-7.0 to simulate strong ground motions, Geophysical Journal International, 204, 1254-1265. doi: 10.1093/gji/ggv521
  • Song, S.G., Dalguer, L.A. and Mai, P.M. (2014) Pseudo-dynamic source modeling with 1-point and 2-point statistics of earthquake source parameters, Geophysical Journal International, 196, 1770-1786. doi: 10.1093/gji/ggt479 SCEC Contribution 2022
The site response method written by RWGraves, included in the BBP, is based on this reference:
  • Atkinson, G. M., Seyhan, E., Stewart, J. P., & Boore, D. M. (2014). NGA-West2 Equations for Predicting PGA, PGV, and 5% Damped PSA for Shallow Crustal Earthquakes. Earthquake Spectra, 30(3), 1057-1085. doi: 10.1193/070113EQS184M SCEC Contribution 8860

Selected Publications

  • Lin, T., Deierlein, G., Zhong, K., & Yen, W. (2020, 09). SCEC Broadband Platform (BBP) ground motion simulations for tall building response analyses in San Francisco, Los Angeles downtown, and CyberShake sites. Oral Presentation at 17th World Conference on Earthquake Engineering (17WCEE). SCEC Contribution 10792
  • Wang, N., Olsen, K. B., & Day, S. M. (2021). A frequency-dependent ground-motion spatial correlation model of within-event residuals for Fourier amplitude spectra. Earthquake Spectra, 37(3), 2041-2065. doi: 10.1177/8755293020981995 SCEC Contribution 10911
  • Zhong, K., Lin, T., Deierlein, G., Graves, R.W., Silva, F., & Luco, N. (2020). Tall building performance-based seismic design using SCEC broadband platform site-specific ground motion simulations. Earthquake Engineering & Structural Dynamics, 50, 81 - 98. doi: 10.1002/eqe.3364 SCEC Contribution 10793
  • Wang, N. (2019). Broadband Ground-Motion Simulation with Inter-Frequency Correlations. Bull. Seis. Soc. Am., 2019;; 109 (6): 2437–2446. doi: https://doi.org/10.1785/0120190136 SCEC Contribution  9932
  • Silva, F., Maechling, P. J., Goulet, C. A., Jordan, T. H., Graves, R. W., Olsen, K. B., Archuleta, R. J., Atkinson, G. M., Pitarka, A., Anderson, J. G., & Song, S. (2018, 06). Using the SCEC Broadband Platform for Strong Ground Motion Simulation and Validation. Poster Presentation at 11th National Conference on Earthquake Engineering. SCEC Contribution 8994