NGA-Subduction research program

Yousef Bozorgnia, Norman A. Abrahamson, Sean K. Ahdi, Timothy D. Ancheta, Linda Al Atik, Ralph J. Archuleta, Gail M. Atkinson, David M. Boore, Kenneth W. Campbell, Brian S-J Chiou, Victor Contreras, Robert B. Darragh, Sahar Derakhshan, Jennifer L. Donahue, Nick Gregor, Zeynep Gulerce, I. M. Idriss, Chen Ji, Tadahiro Kishida, Albert R. KottkeNicolas Kuehn, Dong Youp Kwak, Annie O-L Kwok, P. Lin, Jorge Macedo, Silvia Mazzoni, Saburoh Midorikawa, Sifat Muin, Grace A. Parker, Sanaz Rezaeian, Hongjun Si, Walter J. Silva, Jonathan P. Stewart, Melanie Walling, Katie Wooddell, Robert R. Youngs

Research output: Contribution to journalArticlepeer-review

27 Scopus citations


This article summarizes the Next Generation Attenuation (NGA) Subduction (NGA-Sub) project, a major research program to develop a database and ground motion models (GMMs) for subduction regions. A comprehensive database of subduction earthquakes recorded worldwide was developed. The database includes a total of 214,020 individual records from 1,880 subduction events, which is by far the largest database of all the NGA programs. As part of the NGA-Sub program, four GMMs were developed. Three of them are global subduction GMMs with adjustment factors for up to seven worldwide regions: Alaska, Cascadia, Central America and Mexico, Japan, New Zealand, South America, and Taiwan. The fourth GMM is a new Japan-specific model. The GMMs provide median predictions, and the associated aleatory variability, of RotD50 horizontal components of peak ground acceleration, peak ground velocity, and 5%-damped pseudo-spectral acceleration (PSA) at oscillator periods ranging from 0.01 to 10 s. Three GMMs also quantified “within-model” epistemic uncertainty of the median prediction, which is important in regions with sparse ground motion data, such as Cascadia. In addition, a damping scaling model was developed to scale the predicted 5%-damped PSA of horizontal components to other damping ratios ranging from 0.5% to 30%. The NGA-Sub flatfile, which was used for the development of the NGA-Sub GMMs, and the NGA-Sub GMMs coded on various software platforms, have been posted for public use.

Original languageBritish English
Pages (from-to)783-798
Number of pages16
JournalEarthquake Spectra
Issue number2
StatePublished - May 2022


  • attenuation
  • Ground motion models
  • Next Generation Attenuation for Subduction
  • NGA
  • seismic hazard
  • subduction earthquakes


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