NGA-West2 Flatfiles and GMPE Reports Now Available!

PEER’s NGA-West2 Program, one of our largest multi-year multidisciplinary mega research projects, is reaching its conclusion on various tasks and the first of its final products are now available! These products include many published reports describing the newly updated ground motion prediction equations (GMPEs) and other research studies supporting GMPE development, along with the NGA-West2 Database Flatfile.

NGA-West2, which is the Phase 2 of the Next Generation Attenuation relationships for shallow crustal earthquakes in active tectonic regions, has been coordinated by PEER and financially supported by the California Earthquake Authority (CEA), California Department of Transportation (Caltrans) and Pacific Gas & Electric Company (PG&E). Similar to the previous phase, NGA-West2 will have major impacts on the entire earthquake engineering community. For example, the USGS is reviewing the NGA-West2 GMPEs to consider their adoption for the upcoming US National Seismic Hazard Maps. Site-specific applications will also be affected by the NGA-West2 products.


In the tradition of the openness, the NGA-West2 database “flatfiles” used in various research components of NGA-West2 have also been posted at PEER website: NGA-West2

The actual time series of the database for download have been incorporated into an updated version of the online user-friendly PEER Ground Motion Database at NGA-West2


The following final reports from various NGA-West2 sub-projects are now available for free download on the PEER Reports page.

PEER 2013/03 – PEER NGA-West2 Database
by Timothy D. Ancheta, Robert B. Darragh, Jonathan P. Stewart, Emel Seyhan, Walter J. Silva, Brian S.J. Chiou, Katie E. Wooddell, Robert W. Graves, Albert R. Kottke, David M. Boore, Tadahiro Kishida, and Jennifer L. Donahue

PEER 2013/04 – Update of the AS08 Ground-Motion Prediction Equations Based on the NGA-West2 Data Set
by Norman A. Abrahamson, Walter J. Silva, and Ronnie Kamai

PEER 2013/05 – NGA-West2 Equations for Predicting Response Spectral Accelerations for Shallow Crustal Earthquakes
by David M. Boore, Jonathan P. Stewart, Emel Seyhan, and Gail M. Atkinson

PEER 2013/06 – NGA-West2 Campbell-Bozorgnia Ground Motion Model for the Horizontal Components of PGA, PGV, and 5%-Damped Elastic Pseudo-Acceleration Response Spectra for Periods Ranging from 0.01 to 10 sec
by Kenneth W. Campbell and Yousef Bozorgnia

PEER 2013/07 – Update of the Chiou and Youngs NGA Ground Motion Model for Average Horizontal Component of Peak Ground Motion and Response Spectra
by Brian S.J. Chiou and Robert R. Youngs

PEER 2013/08 – NGA-West2 Model for Estimating Average Horizontal Values of Pseudo-Absolute Spectral Accelerations Generated by Crustal Earthquakes
by I. M. Idriss

PEER 2013/09 – Final Report of the NGA-West2 Directivity Working Group
by Paul Spudich, Jeffrey R. Bayless, Jack W. Baker, Brian S.J. Chiou, Badie Rowshandel, Shrey K. Shahi, and Paul Somerville

PEER 2013/10 – NGA-West2 Models for Ground-Motion Directionality
by Shrey K. Shahi and Jack W. Baker

PEER 2013/11 – Epistemic Uncertainty for NGA-West2 Models
by Linda Al Atik and Robert R. Youngs

PEER 2013/12 – Nonlinear Horizontal Site Response for the NGA-West2 Project
by Ronnie Kamai, Norman A. Abrahamson, Walter J. Silva

PEER 2013/13 – Semi-Empirical Nonlinear Site Amplification and its Application in NEHRP Site Factors
by Jonathan P. Stewart and Emel Seyhan (available in summer 2013)

PEER 2013/14 – Hanging-Wall Scaling using Finite-Fault Simulations
by Jennifer L. Donahue and Norman A. Abrahamson

PEER 2012/01 – Spectral Damping Scaling Factors for Shallow Crustal Earthquakes in Active Tectonic Regions
by Sanaz Rezaeian, Yousef Bozorgnia, I.M. Idriss, Kenneth Campbell, Norman Abrahamson and Walter Silva (sub-project previously published in 2012 on the issue of damping scaling of response spectra)

Next Steps

The task for vertical ground motion is still underway and will be completed in late summer 2013.
PEER and EERI are currently planning a traveling seminar series for Fall 2013 that will describe the NGA-West2 findings, discuss the implementation of the new GMPEs and other research outcomes, and summarize the impacts on the earthquake engineering community.  These seminars will be held in Southern California, Northern California, Seattle, and Utah.  More details will be sent as these events approach!