Spatial correlation of earthquake ground motion intensities

Graduate researchers: Christophe Loth, Nirmal Jayaram

Collaborators: Paolo Bazzurro, Jaesung Park and Polsak Tothong, AIR Worldwide

Project sponsors: U.S. Geological Survey, National Science Foundation

Many seismic loss problems (such as damage of distributed infrastructure and losses to portfolios of structures) are dependent upon the regional distribution of ground motion intensity, rather than intensity at only a single site. This work extends traditional probabilistic seismic hazard analysis (which considers distributions of future event magnitudes, distances, attenuation variability, etc.), to consider spatial distribution of intensity. Spatial correlations of this intensity have been developed empirically based on data from well-recorded past earthquakes. This can then be used in forward simulations of ground motion intensity in future earthquakes. When implemented in a Monte Carlo simulation, one may obtain millions of simulations of intensity from future events, so methods have been developed to select a greatly reduced number of representative events from a large number of simulations. This will facilitate computationally-intensive risk analyses of distributed infrastructure systems such as transportation networks. Models resulting from this work have been utilized by insurance and reinsurance companies, and in more general efforts such as the Global Earthquake Model.

Selected publications:

Loth, C., and Baker, J. W. (2013). “A spatial cross-correlation model of ground motion spectral accelerations at multiple periods.” Earthquake Engineering & Structural Dynamics, 42(3), 397–417. Example Matlab script.
Miller, M., and Baker, J. W. (2013). “A Framework for Selecting A Suite Of Ground-Motion Intensity Maps Consistent With Both Ground-Motion Intensity And Network Performance Hazards For Infrastructure Networks.” 11th International Conference on Structural Safety & Reliability, New York, NY, 8p.
Baker, J. W., and Miller, M. (2011). “Effects of earthquake source geometry and site conditions on spatial correlation of earthquake ground motion hazard.” Keynote lecture at 4th IASPEI/IAEE International Symposium on Effects of Surface Geology on Seismic Motion, Santa Barbara, California, 12p.
Jayaram, N. (2010). Probabilistic seismic lifeline risk assessment using efficient sampling and data reduction techniques. Ph.D. Thesis. Dept. of Civil and Environmental Engineering, Stanford University, Stanford, CA. 286p.
Jayaram, N., and Baker, J. W. (2010). "Efficient sampling and data reduction techniques for probabilistic seismic lifeline risk assessment," Earthquake Engineering & Structural Dynamics, 39(10), 1109-1131.
Jayaram, N., and Baker, J. W. (2010). “Considering spatial correlation in mixed-effects regression, and impact on ground-motion models.” Bulletin of the Seismological Society of America, (in press).
Jayaram, N., and Baker, J. W. (2010). “Characterizing spatial cross-correlation between ground-motion spectral accelerations at multiple periods.” 9th US National and 10th Canadian Conference on Earthquake Engineering, Toronto, Canada, 7p.
Jayaram N. and Baker J.W. (2009). "Correlation model for spatially-distributed ground-motion intensities," Earthquake Engineering and Structural Dynamics, 38(15), 1687-1708.
Jayaram, N. and Baker J.W. (2009). "Efficient sampling techniques for seismic risk assessment of lifelines." Proceedings, 10th International Conference on Structural Safety and Reliability (ICOSSAR09), Kobe, Japan. 8p.
Jayaram, N. and Baker J.W. (2009). "Deaggregation of lifeline risk: Insights for choosing deterministic scenario earthquakes." Proceedings, TCLEE2009 Conference: Lifeline Earthquake Engineering in a Multihazard Environment, Oakland, California. 10p.
Jayaram N. and Baker J.W. (2008). "Statistical tests of the joint distribution of spectral acceleration values," Bulletin of the Seismological Society of America, 98 (5), 2231-2243.
Baker, J.W. and Jayaram, N. (2008). "Effects of spatial correlation of ground motion parameters for multi-site seismic risk assessment: Collaborative research with Stanford University and AIR." Final Technical Report for U.S. Geological Survey National Earthquake Hazards Reduction Program (NEHRP) External Research Program Award 07HQGR0031. 69p.
Park J., Bazzurro P., and Baker J.W. (2007). "Modeling spatial correlation of ground motion intensity measures for regional seismic hazard and portfolio loss estimation," in 10th International Conference on Application of Statistic and Probability in Civil Engineering (ICASP10), Tokyo, Japan, 8 pp.