Thomas Pratt, Ph.D.


Thomas Pratt is a Research Geophysicist with the U.S. Geological Survey based in Reston, Virginia, and a member of the Geologic Hazards Science Center in Golden, Colorado. His research interests are in seismic imaging of active fault systems, modeling of geologic structures, studying the tectonic settings of earthquakes, and understanding ground motions during earthquakes.



Cornell University        BA, Geology, 1980

Virginia Tech               M.Sc., Geophysics, 1982

Virginia Tech               Ph.D.,  Geophysics, 1986


Professional Positions

Research Geophysicist, USGS, Reston, VA, 2013-present.

Central and Eastern Region Coordinator, USGS Earthquake Hazards Program, 2017-present.

Editor-in-Chief, Bulletin of the Seismological Society America, 2016-2021.

Acting External Grants Program Manager, USGS, 2016 (4-month term).

Associate Editor, Bulletin of the Seismological Society America, 2014-2015.

Research Geophysicist, USGS, Seattle, WA, 1994-2013.

Affiliate Professor, Dept. of Earth and Space Sciences, University of Washington, 2003-2014.

Affiliate Professor, School of Oceanography, University of Washington, 2004-2014.

Visiting Professor, Earthquake Research Institute, University of Tokyo, May 5 - August 5, 2000.

Affiliate, School of Oceanography, University of Washington, 1994-2003.

Research Geophysicist, USGS, Golden, CO, 1991-1994.

Associate Editor, Journal of Geophysical Research, 1991-1995.

Research Associate, Department of Earth Sciences, Cornell University, Ithaca, NY, 1989-1991.

Postdoctoral Research Associate, Department of Earth Sciences, Cornell University, Ithaca, NY, 1986-1989.



Chair, Seismological Society of America Best Student Presentation subcommittee, 2010-2011.

Member, Seismological Society of America Awards Committee, 2010-2011.

Subject Matter Expert, USGS “Requirements, Capabilities and Analysis for Earth Observations (RCA-OE)” – a USGS-wide exercise to evaluate capabilities and needs. August-October, 2014.

Member, Hiring Committee, Earthquake Hazards Program External Grants Manager (April-May, 2016)

Member (USGS Representative), FEMA 2019 New Madrid Exercise “Shaken Fury”, Interagency Core Planning Team – 2018-2019

Member, Program for Array Seismic Studies of the Continental Lithosphere (PASSCAL) Standing Committee, Incorporated Research Institutions for Seismology (IRIS), 1994-1998 and 2007-2010.

Chair, Seismological Society of America Best Student Presentation committee, 2010-2011.

Co-Chair (2009-2010), Incorporated Research Institutes for Seismology (IRIS) Active Source Committee; With Alan Levander of Rice University


Selected Publications

Pratt, T.L., Shah, A.K., Counts, R. Horton, J.W., Jr., and Chapman, M.C., 2021, Shallow Faulting in the Epicentral Area of the 1886 Charleston, South Carolina Earthquake, Bulletin of the Seismological Society of America

Pratt, T.L. and Schleicher, L.M., 2021, Characterizing ground motion amplification by extensive flat sediments: The seismic response of the eastern U.S. Atlantic Coastal Plain strata, Bulletin of the Seismological Society of America.

Schleicher, L.M. and Pratt, T.L., 2021, Evaluating Spectral Ratio Methods for Computing Low-frequency Site Responses on flat sediments: An example from the Atlantic Coastal Plain, Eastern United States, Bulletin of the Seismological Society of America.

Wirth, E.A., Vidale, J.E., Frankel, A.D., Pratt T.L., Marafi, N. A., Thompson M., and Stephenson W.J., 2019, Source-Dependent Amplification of Earthquake Ground Motions in Deep Sedimentary Basins. Geophysical Research Letters. doi: 10.1029/2019GL082474. [Link]

Pratt, T.L., 2018, Characterizing and imaging sedimentary strata using depth-converted spectral ratios: An example from the Atlantic Coastal Plain sedimentary strata of the eastern United States, Bulletin of the Seismological Society of America, v. 108(5A), 2801-2815. doi: 10.1785/0120180046. [Link]

Pratt, T.L., Horton, J.W., Jr., Muñoz, J., Hough, S.E., and Chapman, M., 2017, Amplification of earthquake ground motions in Washington, DC, and implications for hazard assessments in the central and eastern North America, Geophysical Research Letters. doi 10.1002/2017GL075517. [Link]

Scales, M.M., DeShon, H.R., Magnani, M.B., Walter, J.I., Quinones, L., Pratt, T.L., and Hornback, M.J., 2017, A decade of induced slip on the causative fault of the 2015 Mw4.0 Venus earthquake, Northeast Johnson County, Texas, Journal of Geophysical Research, 122, p1-16. Doi:10.1002/2017JB014460. [Link]

Bergen, K.J., Shaw, J.H., Leon, L.A., Dolan, J.F., Pratt, T.L., Ponti, D.J., Morrow, E., Barrera, W., Rhodes, E.J., Murari, M.K., and Owen, L.A., 2017, Accelerating slip rates on the Puente Hills blind thrust fault system beneath metropolitan Los Angeles, California, USA, Geology, G38520.1, 4 pp. doi:10.1130/G38520.1 [Link]

Love, K.B., Hallet, B., Pratt, T.L., and O’Neel, S., 2016, Observations and modeling of fjord sedimentation during the 30 year retreat of Columbia Glacier, AK, Journal of Glaciology, v. 62, p. 778-793, doi: 10.1017/jog.2016.67. [Link]

Odum, J.K., Stephenson, W.J., Pratt, T.L., and Blakely, R.J., 2016, Shallow geophysical imaging of the Olympia anomaly: An enigmatic structure in the southern Puget Lowland, Washington State, Geosphere, v. 12, no. 5, 16 pp., doi: 10.1130/GES01248.1. [Link]

Stephenson, W.J., Odum, J.K., Wicks, C.W., Pratt, T.L. and Blakely, R.J., 2016, Seismic imaging beneath an InSAR anomaly in eastern Washington State: Shallow faulting associated with an earthquake swarm in a low-hazard area, Bulletin of the Seismological Society of America, v. 106, no. 4. doi:10.1785/0120150295. [Link]

Pratt, T.L., Troost, K.G., Stephenson, W., and Odum, J., 2015, Kinematics of shallow backthrusts in the Seattle fault zone, Washington State, Geosphere, v. 11, no. 6, p. 1948-1974. doi:10.1130/GES01179.1 [Link]

McAuliffe, L.J., Dolan, J.F., Rhodes, E.J., Hubbard, J., Shaw, J.H., and Pratt, T.L., 2015, Paleoseismologic evidence for large-magnitude (Mw≥7.5) earthquakes on the Ventura blind thrust fault: Implications for multi-fault ruptures in the Transverse Ranges of southern California, Geosphere, v. 11, no. 5, p. 1629-1650. doi:10.1130/GES01123.1 [Link]

Finn, S.P., Liberty, L.M., Haeussler, P.J., and Pratt, T.L., 2015, Active faults and landslide deposits beneath eastern Prince William Sound, Alaska, Bulletin of the Seismological Society of America, v. 105, no. 5, p. 2343-2353. doi:10.1785/0120140273. [Link]

Pratt, T.L., Horton, J.W., Jr., Spears, D.B., Gilmer, A.K., and McNamara, D.E., 2015, The 2011 Virginia Mw 5.8 earthquake: Insights from seismic reflection imaging into the influence of older structures on eastern U.S. seismicity, in Horton, J.W., Jr., Chapman, M.C., and Green, R.A., eds., The 2011 Mineral, Virginia, Earthquake, and Its Significance for Seismic Hazards in Eastern North America: Geological Society of America Special Paper 509, p. 1–10, doi:10.1130/2015.2509(16). [Link]

Haeussler, P.J., Armstrong, P.A., Liberty, L., Ferguson, K., Finn, S., Arkle, J., and Pratt, T.L., 2015, Focused exhumation along megathrust splay faults in Prince William Sound, Alaska, Quaternary Science Reviews, Volume 113, 1 April 2015, Pages 8–22. doi:10.1016/j.quascirev.2014.10.013. [Link]

Coleman, J.L., Jr., and Pratt, T.L., 2015, Examination of the Reelfoot rift petroleum system, south-central United States, and the elements that remain for potential exploration and development, 2015 Gulf Coast Section Society for Sedimentary Geology (GCSSEPM) Research Foundation proceedings, in press

Casale, G. and Pratt, T.L., 2015, Thin-skin or thick-skin faulting in the Yakima Fold and Thrust Belt of central Washington State?: Constraints from kinematic modeling of the Saddle Mountains Anticline,Bulletin of the Seismological Society of America, v. 105, p.1042-1048. doi:10.1785/0120140207. [Download File]

Hubbard, J., Shaw, J.H., Dolan, J., Pratt, T.L., McAuliffe, L., and Rockwell, T.K., 2014, Structure and seismic hazard of the Ventura Avenue anticline and Ventura fault, California: Prospect for large, multisegment ruptures in the Western Transverse Ranges, Bulletin of the Seismological Society of America, v. 105, p. 1070-1087. doi:10.1785/0120130125. [Link]

Liberty, L.M., Finn, S.P., Haeussler, P.J., Pratt, T.L. and Peterson, A., 2013, Megathrust splay faults at the focus of the Prince William Sound asperity, Alaska, Journal of Geophysical Research, v. 118, 1–14, doi:10.1002/jgrb.50372. [Link]

Pratt, T.L., 2012, Large-scale splay faults on a strike-slip fault system: The Yakima Folds, Washington State, Geochemistry, Geophysics, Geosystems (G-Cubed), v. 13, Q11004, 14 pp. doi:10.1029/2012GC004405. [Link]

Pratt, T.L., 2012, Kinematics of the New Madrid Seismic zone, Central United States, based on stepover models, Geology, v. 40, p. 371-374. doi:10.1130/G32624.1. [Link]

Pratt, T.L., Williams, R.A., Odum, J.K., and Stephenson, W.J., 2012, Origin of the Blytheville Arch, and long-term displacement on the New Madrid seismic zone, central United States, in Cox, R.T., Tuttle, M.P., Boyd, O.S., and Locat, J., eds., Recent Advances in North American Paleoseismology and Neotectonics East of the Rockies: Geological Society of America Special Paper 493, p. 1–15, doi:10.1130/2012.2493(01). [Link]

Lamb, A.P., Liberty, L.M.L., Blakely, R.J., Pratt, T.L., Sherrod, B.L., and van Wijk, K., 2012, The western limits of the Seattle fault zone and its interaction with the Olympic Peninsula, Washington,Geosphere, v. 8, no. 4, p. 1-16. doi:10.1130/GES00780.1. [Link]

Barnett, E.A., Haugerud, R.A., Sherrod, B.L., Weaver, C.S., Pratt, T.L., and Blakely, R.J., 2010, Preliminary atlas of active shallow tectonic deformation in the Puget Lowland, Washington, U.S. Geological Survey Open File Report 2010-1149. [Link]

Pratt, T.L., and Dolan, J. F., 2010, Comment on “Near-Surface Location, Geometry, and Velocities of the Santa Monica Fault Zone, Los Angeles, California,” Bulletin of the Seismological Society of America, v. 100; no. 5A; p. 2329-2337. [Download File]

Clement, C.R., Pratt, T.L., Holmes, M.L., and Sherrod, B.L., 2010, High-Resolution Seismic Reflection Imaging of Growth Folding and Shallow Faults beneath the Southern Puget Lowland, Washington State,Bulletin Seismological Society America, v. 100; no. 4; p. 1710-1723. [Download File]

Leon, L. A., J. F. Dolan, J. H. Shaw, and T. L. Pratt, 2009, Evidence for large Holocene Earthquakes on the Compton Thrust Fault, Los Angeles, California, Journal of Geophysical Research, v. 114, B12305 doi: 10.1029/2008JB00619. [Link]

Liberty, L.M., Pratt, T.L., Lyle, M., and Madin, I.P., 2009, Seismic Reflection Imaging of Complex Structures beneath Upper Klamath Lake, Oregon: Neotectonic Implications, in Oldow, J.S. and P. Cashman, eds., Late Cenozoic Structure and Evolution of the Great Basin – Sierra Nevada Transition: Geological Society of America Special Paper 447, p. 71-82. [Link]

Pratt, T.L., 2009, Finding trapped miners using a prototype seismic recording system made from music-recording hardware, U. S. Geological Survey Open File Report 2009-1095, 38p. [Link]

Liberty, L.M. and Pratt, T.L., 2008, Structure of the Eastern Seattle Fault Zone, Washington State: New Insights from Seismic Reflection Data, Bulletin of the Seismological Society of America, v. 98; no. 4; p. 1681-1695; DOI: 10.1785/0120070145. [Download File]

Leon, L. A., Christofferson, S.A., Dolan, J.F., Shaw, J.H., and Pratt, T.L., 2007, Earthquake-by-earthquake fold growth above the Puente Hills blind thrust fault, Los Angeles, California: Implications for fold kinematics and seismic hazard, Journal of Geophysical Research, 112, B03S03, doi:10.1029/2006JB004461. [Link]

Snelson, C.M., Brocher, T.M., Miller, K.C., Pratt, T.L. and Tréhu, A.M., 2007, Seismic Amplification Within the Seattle Basin, Washington State: Insights from SHIPS Seismic Tomography Experiments,Bulletin of the Seismological Society of America, v. 97; no. 5; p. 1432-1448; DOI: 10.1785/0120050204. [Download File]

Pratt, T.L., 2006, Basin effects and ground shaking in the Puget Lowland, Washington State, USA, Bulletin of the Earthquake Research Institute (University of Tokyo), 81, 283-289. [Link]

Stephenson, W. J., A. D. Frankel, J. K. Odum, R. A. Williams, and T. L. Pratt, 2006, Toward resolving an earthquake ground motion mystery in west Seattle, Washington State: Shallow seismic focusing may cause anomalous chimney damage, Geophysical Research Letters, 33, L06316, doi:10.1029/2005GL025037. [Link]

Liberty, L.M., Pratt, T.L., and Hess, S.S., 2006, Seeing through the noise: seismic reflection profiling in urban areas, Proceedings of the 2006 Symposium on the Application of Geophysics to Engineering and Environmental Problems (SAGEEP), p. 492-498. [Link]

Pratt, T.L., 2006, Site response, basin effects, and attenuation in the Puget Lowland, Washington State, USA, Proceedings of the 2006 Symposium on the Application of Geophysics to Engineering and Environmental Problems (SAGEEP), p. 274-282. [Link]

Liberty, L.M. and Pratt, T.L., 2006, Recent high-resolution seismic reflection studies of active faults in the Puget Lowland, Proceedings of the 2006 Symposium on the Application of Geophysics to Engineering and Environmental Problems (SAGEEP), p. 254-259. [Link]

Pratt, T.L., Templeton, M.E., Frost, R., and Shafer, A., 2006, Variations in short-period geophone responses in temporary seismic arrays, Seismological Research Letters, v. 77, p. 377-388. [Link]

Pratt, T.L., and Brocher, T.M., 2006, Site response and attenuation in the Puget Lowland, Washington State, Bulletin of the Seismological Society of America, v. 96, p. 536-552. [Download File]

Barberopoulou, A., Qamar, A., Pratt, T.L., and Steele, W., 2006, Long-Period Effects of the Denali Earthquake on Water Bodies in the Puget Lowland: Observations and Modeling, Bulletin of the Seismological Society of America, v. 96, p. 519-535. [Download File]

Li, Q., Wilcock, W.S.D., Pratt, T.L., Snelson, C.M., and Brocher, T.M., 2006, Seismic attenuation structure of the Seattle basin, Washington State, from explosive-source refraction data, Bulletin of the Seismological Society of America, v. 96, p. 553-571. [Download File]

Pratt, T.L., Meagher, K., Brocher, T.M., Weaver, C.S., Yelin, T., Hultgrien, L., and Barnett, E., 2003, Earthquake and blast recordings from the 2002 Seattle Seismic Hazard Investigation of Puget Sound (SHIPS) Experiment, Washington State, U. S. Geological Survey Open-File Report 03-361. [Link]

Brocher, T.M., Pratt, T.L., Spence, G.D., Reidel, M., and Hyndman R.D., 2003, Wide-angle seismic recordings from the 2002 Georgia Basin geohazards initiative, northwestern Washington and British Columbia, U. S. Geological Survey Open-File Report 03-160. [Link]

Pratt, T.L., Holmes, M., Schweig, E.S., Gomberg, J., and Cowan, H.A., 2003, High resolution seismic imaging of faults beneath Limón Bay, northern Panama Canal, Republic of Panama, Tectonophysics, v. 368, p. 211-227. [Link]

Pratt, T.L., Brocher, T.M., Weaver, C.S., Miller, K.C., Tréhu, A.M., Creager, K.C., and Crosson, R.S., 2003, Amplification of seismic waves by the Seattle basin, Washington State, Bulletin of the Seismological Society of America, v. 93, p. 533-545. [Download File]

Brocher, T.M., Pratt, T.L., Weaver, C.S., Snelson, C.M., and Frankel, A.D., 2002, Implosion, earthquake, and explosion recordings from the 2002 Kingdome Seismic Hazard Investigation of Puget Sound (SHIPS), Washington, U. S. Geological Survey Open-File Report 02-123. [Link]

Pratt, T.L., Shaw, J. H., Dolan, J. F., Christofferson, S., Williams, R. A., Odum, J. K., and Plesch, A., 2002, Shallow seismic imaging of folds above the Puente Hills blind-thrust fault, Los Angeles, California, Geophysical Research Letters, v. 29, no. 9, p. 18-1 – 18-4 (May 8, 2002). [Link]

Pratt, T.L., Weaver, C.S., Brocher, T.M., Parsons, T., Fisher, M.A., Creager, K.C., Crosson, R.S., Hyndman, R.D., Spence, G., Trehu, A.M., Miller, K.C., and ten Brink, U.S., 2002, Understanding the seismotectonics of the Cascadia subduction zone: Overview and recent seismic work, in Fujinawa, Y., and Toshida, A., editors, Seismotectonics in Convergent Plate Boundary, Terra Scientific Publishing, Tokyo, p. 25-36. [Link]

Shaw, J. H., Plesch, A., Dolan, J.F., Pratt, T.L., and Fiore, P., 2002, Puente Hills blind-thrust system, Los Angeles, California, Bulletin of the Seismological Society of America, v. 92, p. 2946-2960.[Download File]

Brocher, T. M., and Pratt, T.L., 2001, Data files from the “Dry SHIPS” recordings of the Chi-Chi earthquake, Seattle, Washington, Bulletin of the Seismological Society of America, v. 91, p. 1395. [Download File]

Stephenson, W.J., Odum, J.K., Williams, R.A., Pratt, T.L., Harrison, R.W., and Hoffman, D., 1999, Deformation and Quaternary faulting in southeast Missouri across the Commerce Geophysical Lineament,Bulletin of the Seismological Society of America, v. 89, p. 140-155. [Download File]

Pratt, T.L., Dolan, J.F., Odum, J.K., Stephenson, W.J., Williams, R.A., and Templeton, M.E., 1998, Multi-scale imaging of active fault zones for hazard assessment: A case study of the Santa Monica fault zone, Los Angeles, California, Geophysics, v. 63, no. 2, p. 1-11. [Link]

Pratt, T.L., Johnson, S.Y., Potter, C.J., Stephenson, W.J., and Finn, C., 1997, Seismic Reflection Images beneath Puget Sound, Western Washington State: The Puget Lowland Thrust Sheet hypothesis,Journal of Geophysical Research, v. 102, no. B12, p. 27,469-27,489. [Link]