Computational Scientist
Computational Scientist

Biography

Dr. Tim C. Johnson is a computational scientist in subsurface geophysical imaging and interpretation related to complex environmental challenges and energy applications.

He is nationally and internationally recognized for his work in electrical resistivity tomography (ERT) as a characterization and monitoring technology. He pioneered the development of E4D-RT, a real-time, four-dimensional subsurface imaging software that allows scientists to “see” subsurface processes and solutions in real time. Tim and his team received a prestigious R&D 100 Award in 2016 for this tool.

Tim joined PNNL in 2010 as a senior research scientist. He worked at Idaho National Laboratory from 2007-2010 and, before that, was a staff engineer at American Geotechnics. Tim is focused on joint inversion of multiple geophysical techniques using parallel computing to improve time-lapse imaging.

Education

  • Doctorate Degree – Geophysics, Boise State University, 2006
  • Bachelor's Degree – Civil Engineering, Boise State University, 2001
  • Bachelor's Degree – Geophysics, Boise State University, 1999

Awards and Recognitions

  • 2017 — Laboratory Director's Award for Exceptional Engineering Achievement in geophysical imaging
  • 2016 — R&D 100 Award for Real-Time Four-Dimensional Subsurface Imaging Software (E4D-RT), R&D Magazine honor for inventors of 100 most technologically significant products each year

Patents

U.S. Patent No. 9,772,423, September 26, 2017, "METHOD OF IMAGING THE ELECTRICAL CONDUCTIVITY DISTRIBUTION OF A SUBSURFACE "(Offsite link).

Publications

2019

  • Johnson T.C., C.E. Strickland, H. Knox, J. Thomle, V.R. Vermeul, C. Ulrich, and T.J. Kneafsey, et al. 2019. "EGS Collab Project Electrical Resistivity Tomography Characterization and Monitoring." In Proceedings of the 44th Workshop on Geothermal Reservoir Engineering, Stanford University, February 11-13, 2019, Stanford California, SGP-TR-214. Stanford, California:Stanford Geothermal Program. PNNL-SA-138913.
  • White M.D., T.C. Johnson, T.J. Kneafsey, D.A. Blankenship, P. Fu, H. Wu, and A. Ghassemi, et al. 2019. "The Necessity for Iteration in the Application of Numerical Simulation to EGS: Examples from the EGS Collab Test Bed 1." In Proceedings of the 44th Workshop on Geothermal Reservoir Engineering, Stanford University, February 11-13, 2019, Stanford California, SGP-TR-214. Stanford, California:Stanford Geothermal Program. PNNL-SA-140831.

2018

  • Dobson P.F., T.J. Kneafsey, J. Morris, A. Singh, M.D. Zoback, B. Roggenthen, and T.W. Doe, et al. 2018. "The EGS Collab Hydroshear Experiment at the Sanford Underground Research Facility - Siting Criteria and Evaluation of Candidate Sites." Transactions - Geothermal Resources Council 42. PNNL-SA-137953.
  • Johnson T.C., and J.N. Thomle. 2018. "3-D Decoupled Inversion of Complex Conductivity Data in the Real Number Domain." Geophysical Journal International 212, no. 1:284-296. PNNL-SA-123575. doi:10.1093/gji/ggx416
  • Johnson T.C., J.N. Thomle, and M.L. Rockhold. 2018. "3D Time-Lapse Geophysical Imaging Evaluation of Contaminant Migration at the Hanford BY Cribs Site." In Proceedings of the 44th Annual Waste Management Conference (WM2018): Nuclear and Industrial Robotics, Remote Systems and Other Emerging Technology, March 18-22, 2018, Phoenix, Arizona, 8, 5438-5451; Paper No. 18504. Tempe, Arizona:Waste Management Symposia, Inc. PNNL-SA-131239.
  • Kneafsey T.J., D.A. Blankenship, P.F. Dobson, H. Knox, T.C. Johnson, J. Ajo-Franklin, and P.C. Schwering, et al. 2018. "EGS Collab Project Experiment 1 Overview and Progress." Transactions - Geothermal Resources Council 42. PNNL-SA-137951.
  • Kneafsey T.J., P.F. Dobson, D.A. Blankenship, J. Morris, H. Knox, P.C. Schwering, and M.D. White, et al. 2018. "An Overview of the EGS Collab Project: Field Validation of Coupled Process Modeling of Fracturing and Fluid Flow at the Sanford Underground Research Facility, Lead, SD." In Proceedings of the 43rd Workshop on Geothermal Reservoir Engineering, Stanford University, February 12-14, 2018, Stanford, California, SGP-TR-213. Stanford, California:Stanford Geothermal Program. PNNL-SA-137949.
  • Kneafsey T.J., P.F. Dobson, J. Ajo-Franklin, C.A. Valladao, D.A. Blankenship, H. Knox, and P.C. Schwering, et al. 2018. "The EGS Collab Project: Stimulation and Simulation." In Proceedings of the 52nd US Rock Mechanics / Geomechanics Symposium, June 17-20, 2018, Seattle, WA, ARMA-2018-1345. Alexandria, Virginia:American Rock Mechanics Association. PNNL-SA-137954.
  • Strickland C.E., M.J. Truex, R.D. Mackley, and T.C. Johnson. 2018. Deep Vadose Zone Monitoring Strategy for the Hanford Central Plateau. PNNL-28031. Richland, WA: Pacific Northwest National Laboratory. Deep Vadose Zone Monitoring Strategy for the Hanford Central Plateau
  • Truex M.J., G.B. Chronister, C.E. Strickland, C.D. Johnson, G.D. Tartakovsky, M. Oostrom, and R.E. Clayton, et al. 2018. Deep Vadose Zone Treatability Test of Soil Desiccation for the Hanford Central Plateau: Final Report. PNNL-26902. Richland, WA: Pacific Northwest National Laboratory. Deep Vadose Zone Treatability Test of Soil Desiccation for the Hanford Central Plateau: Final Report

2017

  • Graham E.B., J.C. Stegen, A.R. Crump, C.T. Resch, S.J. Fansler, E.V. Arntzen, and D.W. Kennedy, et al. 2017. "Organic carbon thermodynamics elucidate spatiotemporal mechanisms governing hyporheic zone biogeochemical cycling." In Proceedings of the Subsurface Biogeochemical Research and Terrestrial Ecosystem Science Joint Meeting April 25-26, 2017, Potomac, Maryland. Washington, District Of Columbia:US Department of Energy, Office of Biological and Environmental Research. PNNL-SA-125130.
  • Gresse M., J. Vandemeulebrouck, S. Byrdina, C. Chiodini, A. Revil, T.C. Johnson, and T. Ricci, et al. 2017. "Three-Dimensional Electrical Resistivity Tomography of the Solfatara Crater (Italy): Implication for the Multiphase Flow Structure of the Shallow Hydrothermal System." Journal of Geophysical Research. Solid Earth 122, no. 11:8749-8768. PNNL-SA-128585. doi:10.1002/2017JB014389
  • Johnson T.C., G. Hammond, and X. Chen. 2017. "PFLOTRAN-E4D: A parallel open source PFLOTRAN module for simulating time-lapse electrical resistivity data." Computers & Geosciences 99. PNNL-SA-113670. doi:10.1016/j.cageo.2016.09.006
  • Knox H., P. Fu, J. Morris, Y. Guglielmi, V.R. Vermeul, J. Ajo-Franklin, and C.E. Strickland, et al. 2017. "Fracture and Flow Designs for the Collab/SIGMA-V Project." Transactions - Geothermal Resources Council 41. PNNL-SA-128292.
  • Oostrom M., M.J. Truex, M.L. Rockhold, and T.C. Johnson. 2017. "Deep Vadose Zone Contaminant Flux Evaluation at the Hanford BY-Cribs Site using Forward and Imposed Concentration Modeling Approaches." Environmental Processes 4, no. 4:771-797. PNNL-SA-127119. doi:10.1007/s40710-017-0272-5

2015

  • Johnson T.C., and D.M. Wellman. 2015. "Accurate modeling and inversion of electrical resistivity data in the presence of metallic infrastructure with known location and dimension." Geophysical Journal International 202, no. 2:1096-1108. PNNL-SA-104673. doi:10.1093/gji/ggv206
  • Johnson T.C., D.F. Rucker, and D.R. Glaser. 2015. "Near-Surface Geophysics at the Hanford Nuclear Site, the United States." In Treatise on Geophysics, Second Edition, edited by G Schubert. 571-595. Amsterdam:Elsevier. PNNL-SA-100920.
  • Johnson T.C., R. Versteeg, F.D. Day-Lewis, W. Major, and J.W. Lane. 2015. "Time-Lapse Electrical Geophysical Monitoring of Amendment-Based Biostimulation." Ground Water 53, no. 6:920-932. PNNL-SA-115558. doi:10.1111/gwat.12291
  • Johnson T.C., R. Versteeg, J.N. Thomle, G.E. Hammond, X. Chen, and J.M. Zachara. 2015. "Four-dimensional electrical conductivity monitoring of stage-driven river water intrusion: Accounting for water table effects using a transient mesh boundary and conditional inversion constraints." Water Resources Research 51, no. 8:6177-6196. PNNL-SA-103949. doi:10.1002/2014WR016129
  • Robinson J., T.C. Johnson, and L.D. Slater. 2015. "Challenges and opportunities for fractured rock imaging using 3D cross-borehole electrical resistivity." Geophysics 80, no. 2:e49-e61. PNNL-SA-111273. doi:10.1190/GEO2014-0138.1
  • Singha K., F.D. Day-Lewis, T.C. Johnson, and L.D. Slater. 2015. "Advances in interpretation of subsurface processes with time-lapse electrical imaging." Hydrological Processes 29, no. 6:15-49-1576. PNNL-SA-110809. doi:10.1002/hyp.10280
  • Strickland C.E., T.C. Johnson, and R.I. Odom. 2015. "Three-Dimensional Fr�chet Sensitivity Kernels for Electromagnetic Wave Propagation." Geophysical Journal International 203, no. 1:482-505. PNNL-SA-106439. doi:10.1093/gji/ggv272
  • Truex M.J., C.E. Strickland, M. Oostrom, C.D. Johnson, G.D. Tartakovsky, T.C. Johnson, and R.E. Clayton, et al. 2015. Deep Vadose Zone Treatability Test for the Hanford Central Plateau: Interim Post-Desiccation Monitoring Results, Fiscal Year 2015. PNNL-24706. Richland, WA: Pacific Northwest National Laboratory. Deep Vadose Zone Treatability Test for the Hanford Central Plateau: Interim Post-Desiccation Monitoring Results, Fiscal Year 2015
  • Truex M.J., V.R. Vermeul, D. Adamson, M. Oostrom, L. Zhong, R.D. Mackley, and B.G. Fritz, et al. 2015. "Field Test of Enhanced Remedial Amendment Delivery Using a Shear-Thinning Fluid." Ground Water Monitoring and Remediation 35, no. 3:34-45. PNNL-SA-101736. doi:10.1111/gwmr.12101

2014

2013

  • Johnson T.C., and D.M. Wellman. 2013. Re-Inversion of Surface Electrical Resistivity Tomography Data from the Hanford Site B-Complex. PNNL-22520; RPT-DVZ-AFRI-014. Richland, WA: Pacific Northwest National Laboratory. Re-Inversion of Surface Electrical Resistivity Tomography Data from the Hanford Site B-Complex
  • Johnson T.C., M. Oostrom, M.J. Truex, J.N. Thomle, and T.W. Wietsma. 2013. "Determination of water saturation using gas phase partitioning tracers and time-lapse electrical conductivity measurements." Vadose Zone Journal 12, no. 2. PNNL-SA-91015. doi:10.2136/vzj2012.0142
  • Robinson J., T.C. Johnson, and L. Slater. 2013. "Evaluation of known-boundary and resistivity constraints for improving cross-borehole DC electrical resistivity imaging of discrete fractures." Geophysics 78, no. 3:1MJ-Z75. PNNL-SA-90198. doi:10.1190/geo2012-0333.1
  • Truex M.J., M. Oostrom, C.E. Strickland, T.C. Johnson, C.D. Johnson, R.E. Clayton, and G.B. Chronister. 2013. Deep Vadose Zone Treatability Test for the Hanford Central Plateau: Interim Post-Desiccation Monitoring Results. PNNL-22826. Richland, WA: Pacific Northwest National Laboratory. Deep Vadose Zone Treatability Test for the Hanford Central Plateau: Interim Post-Desiccation Monitoring Results
  • Truex M.J., T.C. Johnson, C.E. Strickland, J.E. Peterson, and S.S. Hubbard. 2013. "Monitoring Vadose Zone Desiccation with Geophysical Methods." Vadose Zone Journal 12, no. 2. PNNL-SA-90886. doi:10.2136/vzj2012.0147
  • Wallin E.L., T.C. Johnson, W.J. Greenwood, and J.M. Zachara. 2013. "Imaging high stage river-water intrusion into a contaminated aquifer along a major river corridor using 2D time-lapse surface electrical resistivity tomography." Water Resources Research 49, no. 3:1693-1708. PNNL-SA-88529. doi:10.1002/wrcr.20119
  • Wellman D.M., M.J. Truex, T.C. Johnson, A.L. Bunn, and E.C. Golovich. 2013. Deep Vadose Zone-Applied Field Research Initiative Fiscal Year 2012 Annual Report. PNNL-22322. Richland, WA: Pacific Northwest National Laboratory. Deep Vadose Zone-Applied Field Research Initiative Fiscal Year 2012 Annual Report

2012

  • Johnson T.C., L. Slater, D. Ntarlagiannis, F.D. Day-Lewis, and M. Elwaseif. 2012. "Monitoring groundwater-surface water interaction using time-series and time-frequency analysis of transient three-dimensional electrical resistivity changes." Water Resources Research 48. PNNL-SA-85275. doi:10.1029/2012WR011893
  • Johnson T.C., R.J. Versteeg, M.L. Rockhold, L.D. Slater, D. Ntarlagiannis, W.J. Greenwood, and J.M. Zachara. 2012. "Characterization of a contaminated wellfield using 3D electrical resistivity tomography implemented with geostatistical, discontinuous boundary, and known conductivity constraints." Geophysics 77, no. 6:EN85-EN96. PNNL-SA-86781. doi:10.1190/geo2012-0121.1
  • Johnson T.C., W.J. Greenwood, C.E. Strickland, M.J. Truex, V.L. Freedman, G.B. Chronister, and D.F. Rucker. 2012. "3D Characterization and Time-Lapse Imaging of the Desiccation Treatability Test at the Hanford BC-Cribs and Trenches Site using High Performance Electrical Resistivity Imaging." In Annual Waste Management Symposium (WM2012): Improving the Future in Waste Management, February 26 - March 1, 2012, Pheonix AZ, 2181-2189. Tucson, Arizona:Waste Management Symposia, Inc. PNNL-SA-84065.
  • Meyer J., E.W. Bethel, J.L. Horsman, S.S. Hubbard, H. Krishnan, A. Romosan, and E. Keating, et al. 2012. "Visual Data Analysis as an Integral Part of Environmental Management." IEEE Transactions on Visualization and Computer Graphics 18, no. 12:2088 - 2094. PNNL-SA-80187. doi:10.1109/TVCG.2012.278
  • Szecsody J.E., M.J. Truex, L. Zhong, T.C. Johnson, N. Qafoku, M.D. Williams, and W.J. Greenwood, et al. 2012. "Geochemical and Geophysical Changes during Ammonia Gas Treatment of Vadose Zone Sediments for Uranium Remediation." Vadose Zone Journal 11, no. 4. PNNL-SA-86840. doi:10.2136/vzj2011.0158
  • Truex M.J., M. Oostrom, C.E. Strickland, T.C. Johnson, V.L. Freedman, C.D. Johnson, and W.J. Greenwood, et al. 2012. Deep Vadose Zone Treatability Test for the Hanford Central Plateau: Soil Desiccation Pilot Test Results. PNNL-21369. Richland, WA: Pacific Northwest National Laboratory. Deep Vadose Zone Treatability Test for the Hanford Central Plateau: Soil Desiccation Pilot Test Results
  • Wellman D.M., M.D. Freshley, T.C. Johnson, and A.L. Miracle. 2012. "Contaminants in Vadose Zone Environments." Vadose Zone Journal 11, no. 4:Article No. 0159. PNNL-SA-93024. doi:10.2136/vzj2012.0159
  • Zhang C., L. Slater, G.D. Redden, Y. Fujita, T.C. Johnson, and D. Fox. 2012. "Spectral Induced Polarization Signatures of Hydroxide Adsorption and Mineral Precipitation in Porous Media." Environmental Science & Technology 8, no. 46:4357-4364. PNNL-SA-89457. doi:10.1021/es204404e

2011

  • Dafflon B., W. Barrash, M. Cardiff, and T.C. Johnson. 2011. "Hydrological parameter estimations from a conservative tracer test with variable-density effects at the Boise Hydrogeophysical Research Site." Water Resources Research 47, no. 12:Article No. W12513. PNNL-SA-79976. doi:10.1029/2011WR010789
  • Dafflon B., W. Barrash, M.A. Cardiff, and T.C. Johnson. 2011. "Hydrological parameter estimations from a conservative tracer test with variable-density effects at the Boise Hydrogeophysical Research Site." Water Resources Research 47. PNNL-SA-89456. doi:10.1029/2011WR010789
  • Johnson T.C., M.J. Truex, D.M. Wellman, and J. Marble. 2011. "Characterization and monitoring of subsurface processes using parallel computing and electrical resistivity imaging." AGU Hydrology Section Newsletter. PNNL-SA-80302.
  • Revil A., M. Karaoulis, T.C. Johnson, and A. Kemna. 2011. "Review: Some Low-Frequency Electrical Methods for Subsurface Characterization and Monitoring in Hydrogeology." Hydrogeology Journal 20, no. 4:617-658. PNNL-SA-77010. doi:10.1007/s10040-011-0819-x
  • Vermeul V.R., B.G. Fritz, J.S. Fruchter, W.J. Greenwood, T.C. Johnson, J.A. Horner, and C.E. Strickland, et al. 2011. 100-NR-2 Apatite Treatability Test: Fall 2010 Tracer Infiltration Test (White Paper). PNNL-20322. Richland, WA: Pacific Northwest National Laboratory. 100-NR-2 Apatite Treatability Test: Fall 2010 Tracer Infiltration Test (White Paper)
  • Wellman D.M., M.B. Triplett, M.D. Freshley, M.J. Truex, R.E. Gephart, T.C. Johnson, and G.B. Chronister, et al. 2011. "DEEP VADOSE ZONE APPLIED FIELD RESEARCH CENTER: TRANSFORMATIONAL TECHNOLOGY DEVELOPMENT FOR ENVIRONMENTAL REMEDIATION." In Proceedings of the 37th Annual Radioactive Waste Management Symposium (WM 2011): Global Achievements and Challenges in Waste Management, February 27-March 3, 2011, Phoenix, Arizona, 6, 4969-4982, Paper No. 11074. Tucson, Arizona:WM Symposia. PNNL-SA-76702.
  • Wellman D.M., M.J. Truex, M.D. Freshley, R.E. Gephart, M.B. Triplett, and T.C. Johnson. 2011. Implementation Plan for the Deep Vadose Zone-Applied Field Research Center. PNNL-20209. Richland, WA: Pacific Northwest National Laboratory. Implementation Plan for the Deep Vadose Zone-Applied Field Research Center
  • Wellman D.M., T.C. Johnson, R.M. Smith, M.J. Truex, and H.E. Matthews. 2011. Deep Vadose Zone-Applied Field Research Initiative Fiscal Year 2011 Annual Report. PNNL-20757. Richland, WA: Pacific Northwest National Laboratory. Deep Vadose Zone-Applied Field Research Initiative Fiscal Year 2011 Annual Report