PACIFIC EARTHQUAKE ENGINEERING RESEARCH CENTER PEER NGA-West2 Database Timothy D. Ancheta Pacific Earthquake Engineering Research Center Robert B. Darragh Pacific Engineering and Analysis Jonathan P. Stewart Emel Seyhan University of California, Los Angeles Walter J. Silva Pacific Engineering and Analysis Brian S. J. Chiou California Department of Transportation Katie E. Wooddell Pacific Gas & Electric Company Robert W. Graves United States Geologic Survey Albert R. Kottke Pacific Earthquake Engineering Research Center David M. Boore United States Geologic Survey Tadahiro Kishida Pacific Earthquake Engineering Research Center PEER 2013/03 MAY 2013 Jennifer L. Donahue Geosyntec Consultants Disclaimer The opinions, findings, and conclusions or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the views of the study sponsor(s) or the Pacific Earthquake Engineering Research Center. PEER NGA-West2 Database Timothy D. Ancheta Pacific Earthquake Engineering Research Center Robert B. Darragh Pacific Engineering and Analysis Jonathan P. Stewart Emel Seyhan University of California, Los Angeles Walter J. Silva Pacific Engineering and Analysis Brian S. J. Chiou California Department of Transporation Katie E. Wooddell Pacific Gas & Electric Company Robert W. Graves United States Geological Survey Albert R. Kottke Pacific Earthquake Engineering Research Center David M. Boore United States Geological Survey Tadahiro Kishida Pacific Earthquake Engineering Research Center Jennifer L. Donahue Geosyntec Consultants PEER Report 2013/03 Pacific Earthquake Engineering Research Center Headquarters at the University of California, Berkeley May 2013 ii ABSTRACT The NGA-West2 project database expands on the current PEER NGA ground-motion database to include worldwide ground-motion data recorded from shallow crustal earthquakes in active tectonic regimes post 2003. Since 2003, numerous well-recorded events have occurred worldwide, including the 2003 M6.6 Bam (Iran), 2004 M6 Parkfield (California), 2008 M7.9 Wenchuan (China), 2009 M6.3 L’Aquila (Italy), 2010 M7.2 El Mayor-Cucupah (California and Mexico), 2010 M7 Darfield (New Zealand), 2011 M6.2 Christchurch (New Zealand), and several well-recorded shallow crustal earthquakes in Japan, among other events. The expanded database also includes 21,336 three-component records from 600 shallow crustal events with small-to-moderate magnitude located in CA. The NGA database has been extensively expanded to include the recorded ground-motion data and metadata, in these and other recent events. The updated database has a magnitude range of 3 to 7.9, and a rupture distance range of 0.05 to 1533 km. The estimated or measured time-averaged shear-wave velocity in the top 30 m at the recording sites (Vs30) ranges from 94 to 2100 m/sec. The NGA-West2 database more than doubles the size of the previous NGA database for moderate-to-large magnitude events (M > 6). The database includes uniformly processed time series as well as response spectral ordinates for 111 periods ranging from 0.01 to 20 sec and 11 different damping ratios. Extensive metadata have also been collected and added to the database. The expanded database is currently being utilized by NGA researchers to update the 2008 ground-motion prediction equations. iii iv ACKNOWLEDGMENTS This project was sponsored by the Pacific Earthquake Engineering Research Center (PEER) and funded by the California Earthquake Authority (CEA), California Department of Transportation, and the Pacific Gas & Electric Company. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect those of the above mentioned agencies. The authors acknowledge Yousef Bozorgnia for his leadership, guidance, and enthusiasm of this multi-year project, and the PEER staff for their editing and project support. We are grateful for Badie Rowshandel’s of the CEA comprehensive review that clarified several important points in the report. The authors gratefully acknowledge the sharing of strong-motion catalog/database and other documentation by the NGA ground motion prediction equation developers especially Norm Abrahamson, Gail Atkinson, Ken Campbell, Ed Idriss, and Bob Youngs. This project and PEER- NGA-West2 would not have succeeded without their unselfish contributions of time, data, informal and formal reviews, guidance, and thoughtful questions and concerns. The authors would also like to thank Dave Wald for providing slopes for stations, Carlos Gutierrez for providing geology and slope based Vs30 estimations, and Alan Yong for his kind help in terrain assignments. We thank Annemarie Baltay for her review of the small-to-moderate magnitude event catalog. Ronnie Kamai and Linda Al Atik kindly carried out QA of the small- to-moderate magnitude data. The staff and agencies that record, process and disseminate earthquake data from California earthquakes are acknowledged both for their long-term efforts in this field, as well as,, response to requests for additional recordings, magnitudes, and other metadata. These are Peggy Helweg of BDSN, Ellen Yu of CIT-SCSN, Tony Shakal, Moh Huang and Hamid Haddadi of CGS-CSMIP, and Chris Stephens of the USGS. In addition, many individuals and organizations also contributed data and expertise to the database development and they have our thanks. These individuals and organizations are Agbabian and Associates, ALYESKA, John Anderson, Jack Boatwright, Roger Borcherdt, Jon Bray, Central Weather Bureau of Taiwan, California Department of Transportation, California Earthquake Authority, CEORKA, Kandilli Observatory and Earthquake Engineering Research Institute of Boğaçizi University, Kevin Clahan, COSMOS, CUREE, Doug Dreger, Bill Ellsworth, ESD, Vladimir Graizer, Tom Hanks, Istanbul Technical University, Japan Meteorological Association, Japan Railroad, Rob Kayen, Kik-Net, K-Net, LADWP, Kandilli Observatory and Earthquake Engineering Research Institute of Boğaçizi University, William H. K. Lee, Martin Mai, NCREE, Bob Nigbor, Pacific Gas & Electric Company, Mark Petersen, Maury Power, Ellen Rathje, Cliff Roblee, Kyle Rollins, ROSRINE, SCEC, Linda Seekins, Seismic Networks (CIT-SCSN-SCEC, ISC, UCB-BDSN, USGS), Shannon and Wilson, Jaime Steidl, Paul Somerville, Paul Spudich, Jon Stewart, Ken Stokoe, USC, URS Corporation, Dave Wald, Jennie Watson-Lamprey, Donald Wells, Kuo-Liang Wen, Chris Wills, and Yuehua Zeng. v vi ERRATA PEER Report No. 2013-03 PEER NGA-West Database July 16, 2013 Page 125, in Appendix D: Column Column Name (units) Description BR Rfn.Clst Obsolete, no longer used BS Rfp.Clst Obsolete, no longer used BT Rfn.Imd Obsolete, no longer used Generalized T Coordinate at the site, produced using the algorithm in BU T Appendix A of Spudich and Chiou (2008) Page 130, in Appendix D: Column Column Name (units) Description Dip of the closest segment for multi-segment/multi-fault events. 0o <= Dip <= JO Dip_seg (deg) 90o. Rake of the closest segment for multi-segment/multi-fault events. -180o <= JP Rake_seg (deg) Rake <= 180o Page 70: RY = -1 * (D + L/2) (4.6) Page 57, top of second paragraph: An outlier in Figure 3.27 is KiK-net site TKCH08 … CONTENTS ABSTRACT .................................................................................................................................. iii ACKNOWLEDGMENTS .............................................................................................................v TABLE OF CONTENTS ........................................................................................................... vii LIST OF FIGURES ..................................................................................................................... xi LIST OF TABLES .................................................................................................................... xvii 1 OVERVIEW OF NGA-WEST2 GROUND MOTION DATABASE ............................1 1.1 Motivation of NGA-West2 Ground Motion Data Set .........................................1 1.2 World-Wide Moderate-to-Large Magnitude Crustal Earthquake Data ..........2 1.3 California Small-to-Moderate Magnitude Data ..................................................5 1.4 Metadata .................................................................................................................7 2 EARTHQUAKE SOURCE TABLE ................................................................................9 2.1 Organization and Objectives of Earthquake Source Table ...............................9 2.2 Finite Fault Models ..............................................................................................10 2.3 Parameters from Multi-Segment Events ...........................................................10 2.4 Earthquake Source Parameters for California Small-To-Moderate Earthquake Data ..................................................................................................12 2.5 Method of Simulating a Finite Fault Geometry ................................................13 2.6 Event Classification: Class 1 Versus Class 2 .....................................................14 2.6.1 Methodology ..............................................................................................16 2.7 Earthquake Swarms ............................................................................................21 2.8 Wenchuan, China, Aftershocks ..........................................................................21 2.8.1 Hypocenter