Brad Aagaard

Earthquake Hazards Program

Research Geophysicist, USGS, 2003-present
USGS Mendenhall Postdoctoral Scholar, 2001-2003

Ph.D., Civil Engineering, California Institute of Technology, 2000
M.S., Civil Engineering, California Institute of Technology, 1995
B.S., Engineering, Harvey Mudd College, 1994

Ground-motion modeling

• Animations of ground shaking from computer simulations of earthquakes.
• 3D Geologic and Seismic Velocity Model of the San Francisco Bay Region

Data files from simulations

Data Files for Ground-Motion Simulations of the 1906 San Francisco Earthquake and Scenario Earthquakes on the Northern San Andreas FaultUSGS Data Series 413

Software

PyLith crustal deformation modeling software, Computational Infrastructure for Geodynamics

Presentations

• USGS Public Lecture: Ground Shaking in the 1989 M6.9 Loma Prieta Earthquake: A view from 25 years later, September 25, 2014

Publications:

Cochran, E.S., Aagaard, B.T., Allen, R.M., Andrews, J., Baltay, A.S., Barbour, A.J., Bodin, P., Brooks, B.A., Chung, A., Crowell, B.W., Given, D.D., Hanks, T.C., Hartog, J.R., Hauksson, E., Heaton, T.H., McBride, S., Meier, M-A., Melgar, D., Minson, S.E., Murray, J.R., Strauss, J.A., and Toomey, D., 2018, Research to improve ShakeAlert earthquake early warning products and their utility: U.S. Geological Survey Open-File Report 2018–1131, 17 p., doi: 10.3133/ofr20181131.

Harris, R.A., M. Barall, B. Aagaard, S. Ma, D. Roten, K. Olsen, B. Duan, B. Luo, D. Liu, K. Bai, J.-P. Ampuero, Y. Kaneko, A.-A. Gabriel, K. Duru, T. Ulrich, S. Wollherr, Z. Shi, E. Dunham, S. Bydlon, Z. Zhang, X. Chen, S.N. Somala, C. Pelties, J. Tago, V.M. Cruz-Atienza, J. Kozdon, E. Daub, K. Aslam, Y. Kase, K. Withers, and L. Dalguer (2018), A suite of exercises for verifying dynamic earthquake rupture codes, Seism. Res. Lett., 89(3), 1146-1162, doi: 10.1785/0220170222.

Aagaard, Brad, Celebi, Mehmet, Gee, Lind, Graves, Robert, Jaiswal, Kishor, Kalkan, Erol, Knudsen, Keith, Luco, Nico, Smith, James, Steidl, Jamison, and Stephens, Christopher, 2017, U.S. Geological Survey National Strong-Motion Project strategic plan, 2017–22: U.S. Geological Survey Open-File Report 2017–1156, 14 p., doi: 10.3133/ofr20171156.

Gary S. Fuis, Klaus Bauer, Mark R. Goldman, Trond Ryberg, Victoria E. Langenheim, Daniel S. Scheirer, Michael J. Rymer, Joann M. Stock, John A. Hole, Rufus D. Catchings, Robert W. Graves, Brad Aagaard "Subsurface Geometry of the San Andreas Fault in Southern California: Results from the Salton Seismic Imaging Project (SSIP) and Strong Ground Motion Expectations," Bulletin of the Seismological Society of America Jul 2017, doi: 10.1785/0120160309

Aagaard, B.T., Blair, J.L., Boatwright, J., Garcia, S.H., Harris, R.A., Michael, A.J., Schwartz, D.P., and DiLeo, J.S., 2016, Earthquake outlook for the San Francisco Bay region 2014–2043 (ver. 1.1, August 2016): U.S. Geological Survey Fact Sheet 2016–3020, 6 p., doi: 10.3133/fs20163020.

Brocher, T.M., A. S. Baltay, J. L. Hardebeck, F. F. Pollitz, J. R. Murray, A. L. Llenos, D. P. Schwartz, J. L. Blair, D. J. Ponti, J. J. Lienkaemper, V. E. Langenheim, T. E. Dawson, K. W. Hudnut, D. R. Shelly, D. Dreger, J. Boatwright, B. T. Aagaard, D. J. Wald, R. M. Allen, W. D. Barnhart, K. L. Knudsen, B. A. Brooks, and K. M. Scharer, 2015, The M6.0 24 August 2014 South Napa Earthquake, Seism. Res. Lett., vol. 86, no. 2A, 309-326, doi:10.1785/0220150004.

Hudnut, K.W., Brocher, T.M., Prentice, C.S., Boatwright, J., Brooks, B.A., Aagaard, B.T., Blair, J.L., Fletcher, J., Erdem, J.E., Wicks, C.W., Murray, J.R., Pollitz, F.F., Langbein, J., Svarc, J., Schwartz, D.P., Ponti, D.J., Hecker, S., DeLong, S., Rosa, C., Jones, B., Lamb, R., Rosinski, A., McCrink, T.P., Dawson, T.E., Seitz, G., Rubin, R.S., Glennie, C., Hauser, D., Ericksen, T., Mardock, D., Hoirup, D.F., and Bray, J.D., 2014, Key recovery factors for the August 24, 2014, South Napa earthquake: U.S. Geological Survey Open-File Report 2014–1249, 51 p., doi: 10.3133/ofr20141249.

Aagaard, B. T., M. G. Knepley, and C. A. Williams (2013), A domain decomposition approach to implementing fault slip in finite-element models of quasi-static and dynamic crustal deformation, Journal of Geophysical Research: Solid Earth, 118, 3059–3079, doi: 10.1002/jgrb.50217.

Aagaard, B. T., J. J. Lienkaemper, and D. P. Schwartz (2012, June), Probabilistic estimates of surface coseismic slip and afterslip for Hayward fault earthquakes, Bulletin of the Seismological Society of America, 103(3), 961-979, doi: 10.1785/0120110200.

Harris, R. A., M. Barall, D. J. Andrews, B. Duan, S. Ma, E. M. Dunham, A. A. Gabriel, Y. Kaneko, Y. Kase, B. T. Aagaard, D. D. Oglesby, J. P. Ampuero, T. C. Hanks, and N. Abrahamson (2011, September/October), Verifying a computational method for predicting extreme ground motion, Seismological Research Letters, 82(5), 638-644,  doi: 10.1785/gssrl.82.5.638.

Graves, R. W. and B. T. Aagaard (2011, April), Testing long-period ground-motion simulations of scenario earthquakes using the Mw 7.2 El Mayor-Cucapah mainshock: Evaluation of finite-fault rupture characterization and 3D seismic velocity models, Bulletin of the Seismological Society of America, 101(2), 895-907, doi: 10.1785/0120100233.

Aagaard, B. T., R. W. Graves, D. P. Schwartz, D. A. Ponce, and R. W. Graymer (2010, December), Ground-motion modeling of Hayward fault scenario earthquakes, Part I: Construction of the suite of scenarios, Bulletin of the Seismological Society of America 100(6), 2927-2944, doi: 10.1785/0120090324.

Aagaard, B. T., R. W. Graves, A. Rodgers, T. M. Brocher, R. W. Simpson, D. Dreger, N. A. Petersson, S. C. Larsen, S. Ma, and R. C. Jachens (2010, December), Ground motion modeling of Hayward fault scenario earthquakes, Part II: Simulation of long-period and broadband ground motions, Bulletin of the Seismological Society of America, 100(6), 2945-2977, doi: 10.1785/0120090379.

Graves, R. W., B. T. Aagaard, and K. W. Hudnut (2010, May), The ShakeOut earthquake source and ground motion simulations, Earthquake Spectra, 27(2), 273-291, doi: 10.1193/1.3570677.

Harris, R. A., M. Barall, R. Archuleta, E. Dunham, B. Aagaard, J. P. Ampuero, H. Bhat, V. Cruz-Atienza, L. Dalguer, P. Dawson, S. Day, B. Duan, G. Ely, Y. Kaneko, Y. Kase, N. Lapusta, Y. Liu, S. Ma, D. Oglesby, K. Olsen, A. Pitarka, S. Song, and E. Templeton (2009, January), The SCEC/USGS Dynamic Earthquake Rupture Code Verification Exercise, Seismological Research Letters, 80(1), 119-126, doi: 10.1785/gssrl.80.1.119.

Graves, R. W., B. T. Aagaard, K. W. Hudnut, L. M. Star, J. P. Stewart, and T. H. Jordan (2008, November 20), Broadband simulations for Mw 7.8 southern San Andreas earthquakes: Ground motion sensitivity to rupture speed, Geophysical Research Letters, 35, L22302,doi:10.1029/2008GL035750.

Aagaard, B. T., and T. H. Heaton (2008, April 8), Constraining fault constitutive behavior with slip and stress heterogeneity, Journal of Geophysical Research, 113, B04301, doi:10.1029/2006JB004793.

Aagaard, B. T. and G. C. Beroza (2008, April), The 1906 San Francisco Earthquake a Century Later: Introduction to the Special Section, Bulletin of the Seismological Society of America 98(2), 817--822, doi: 10.1785/0120060401.

Aagaard, B. T., T. M. Brocher, D. Dolenc, D. Dreger, R. W. Graves, S. Harmsen, S. Hartzell, S. Larsen, M. L. Zoback (2008, April), Ground-Motion Modeling of the 1906 San Francisco Earthquake, Part I: Validation Using the 1989 Loma Prieta Earthquake, Bulletin of the Seismological Society of America 98(2), 989-1011, doi: 10.1785/0120060409.

Aagaard, B. T., T. M. Brocher, D. Dolenc, D. Dreger, R. W. Graves, S. Harmsen, S. Hartzell, S. Larsen, K. McCandless, S. Nilsson, N. A. Petersson, A. Rogers, B. Sjogreen, M. L. Zoback (2008, April), Ground-Motion Modeling of the 1906 San Francisco Earthquake, Part II: Ground-Motion Estimates for the 1906 Earthquake and Scenario Events, Bulletin of the Seismological Society of America 98(2), 1012-1046, doi: 10.1785/0120060410.

McPhee, D. K., V. E. Langenheim, S. Hartzell, R. J. McLaughlin, B. T. Aagaard, R. C. Jachens, and C. McCabe (2007, October), Basin Structure beneath the Santa Rosa Plain, Northern California: Implications for Damage Caused by the 1969 Santa Rosa and 1906 San Francisco Earthquakes, Bulletin of the Seismological Society of America 97(5), 1449-1457, doi: 10.1785/0120060269.

Bakun, W. H., B. Aagaard, B. Dost, W. L. Ellsworth, J. L. Hardebeck, R. A. Harris, C. Ji, M. J. S. Johnston, J. Langbein, J. J. Lienkaemper, A. J. Michael, J. R. Murray, R. M. Nadeau, P. A. Reasenberg, M. S. Reichle, E. A. Roeloffs, A. Shakal, R. W. Simpson and F. Waldhauser (2005, October 13), Nature 437, 969--974, doi: 10.1038/nature04067.

Smith, D. E., B. T. Aagaard, and T. H. Heaton (2005, June), Teleseismic body waves from dynamically rupturing shallow thrust faults: Are they opaque for surface-reflected phases?, Bulletin of the Seismological Society of America 95(3), 800-817, doi: 10.1785/0120030171.

B. T. Aagaard, G. Anderson, and K. Hudnut (2004, December), Dynamic Rupture Modeling of the Transition from Thrust to Strike-Slip Motion in the 2002 Denali Fault, Alaska, Earthquake, Bulletin of the Seismological Society of America 94(6B), S190-S201, doi: 10.1785/0120040614.

B. T. Aagaard and T. H. Heaton (2004, December), Near-Source Ground Motions From Simulations of Sustained Intersonic and Supersonic Fault Ruptures, Bulletin of the Seismological Society of America 94(6), 2064-2078.

B. T. Aagaard, J. F. Hall, and T. H. Heaton (2004, February), Effects of Fault Dip and Slip Rake Angles on Near-Source Ground Motions: Why Rupture Directivity Was Minimal in the 1999 Chi-Chi, Taiwan, Earthquake, Bulletin of the Seismological Society of America 94(1), 155-170, doi: 10.1785/0120030053.

Anderson, G., B. T. Aagaard, and K. Hudnut (2003, December 12), Fault Interactions and Large Complex Earthquakes in the Los Angeles Area, Science 302(5652), 1946-1949, doi: 10.1126/science.1090747.

B. T. Aagaard, T. H. Heaton, and J. F. Hall (2001, December), Dynamic earthquake ruptures in the presence of lithostatic normal stresses: Implications for friction models and heat production, Bulletin of the Seismological Society of America 91(6), 1765-1796, doi: 10.1785/0120000257

B. T. Aagaard, J. F. Hall, and T. H. Heaton (2001, May), Characterization of near-source ground motion with earthquake simulations, Earthquake Spectra 17(2), 177-207, doi: 10.1193/1.1586171.

Duron, Z. H., B. Aagaard, and D. K. Ostrom (1994, December), Spectral estimates of ambient and transient responses of a concrete dam using the maximum entropy method, Dam Engineering 5(4), 31-42. 

Duron, Z. H., D. K. Ostrom, B. Aagaard (1994, May), Measured steady state, ambient, and transient responses of a small arch dam, Dam Engineering 5(1), 43-62.

Duron, Z. H., D. K. Ostrom, B. Aagaard, and B. Fischer (1994, April), Evaluating the behavior of dams during earthquakes, Hydro Review 13(2), 54-52.

Ph.D. Thesis

B. T. Aagaard (1999, October 13), Finite-element simulations of earthquakes, Technical Report 99-03, California Institute of Technology, Earthquake Engineering Research Laboratory, Pasadena, California. Caltech Earthquake Engineering Research Laboratory Technical Reports.

Technical Reports

B. T. Aagaard, J. F. Hall, and T. H. Heaton (2001), Effect of fault dip and slip rake on near-source ground motions: Why Chi-Chi was a relatively mild M 7.6 earthquake, University of California, Berkeley, Pacific Earthquake Engineering Research Center, Berkeley, California.