Dr. Bradley Carr

Research

My geophysical research focuses on the integrated use & development of near surface geophysical methodologies to understand groundwater recharge/movement in mountain headwater environments, hydrothermal systems, the Earth’s Critical Zone, Critical and Energy Mineral deposits, and contaminated (or threatened) aquifers. Currently, I have ongoing Critical Zone and Hydrogeophysical research projects in & around the U.S., Yellowstone National Park geyser & phase separation systems, as well as geophysical characterization and monitoring of Uranium depositional roll fronts in Wyoming, USA.

Due to a vast accumulated experience in applied, theoretical and manufacturing near-surface geophysics as well as exploration seismology since 1988, I work extensively and often with all current near-surface geophysical instrumentation (i.e. surface/borehole reflection and refraction seismology, surface/borehole/marine DC resistivity - induced polarization - self-potential, borehole geophysical logging, surface/borehole nuclear magnetic resonance, total & gradient Magnetics, multifrequency “shallow” electromagnetics, transient “deep” electromagnetics, controlled source magnetotellurics, ground penetrating radar and gravimetry). Also, I operate and collect soil push samples, generate groundwater monitoring wells, and drill rock core samples with the UWNSG Geoprobe 7822DT.

Lastly, I am the Director of the UW Near-Surface Geophysics Instrument Center (UWNSG).  The UWNSG is a cost center that: 1) Rents or provides research service for ~ $3.1M of near-surface geophysical, subsurface push sampling/augering/coring, surveying and associated equipment, 2) Training in the use of the near-surface geophysical instrumentation and geophysical software, 3) Rental of software licenses for near-surface geophysical data analysis, and 4) Data planning, acquisition and analysis services by center staff.

Graduate Students

Stephanie Phillips, Ph.D.
Ang (Leon) Li, Ph.D.
Eva Smith, Ph.D.
Kathleen Van Wesenbeeck, M.S.
Tess Tracy, M.S.
Carson Hall, M.S.

Selected Publications

Li, A., A.D. Parsekian, D. Grana, B.J. Carr, 2025, Quantification of measurement uncertainty in electrical resistivity tomography data and its effect on the inverted resistivity model. Geophysics 90 (3), WA275-WA291.

Bemis, S.P. W.S. Holbrook, B.A. Flinchum, J.L. Hayes, R.P. Callahan, C.J. Harman, B.J. Carr, C.S. Riebe, 2025, Creating a critical zone: Feedbacks between bedrock geology, hydrology and vegetation on an exposed bedrock surface, Panola Mountain. Authorea Preprints.

Pasquet, S., W.S. Holbrook, B.J. Carr, N. Terry, M.A. Briggs, C.A. Finn, P.A. Bedrosian, E. Auken, J. Pedersen, P. Maurya, K.W.W. Sims, 2025, Multi-Scale geophysical imaging of a hydrothermal system in Yellowstone National Park, USA. Journal of Geophysical Research: Solid Earth 130 (4), e2024JB029839.

Pleasants, M.S., T.J. Kelleners, A.D. Parsekian, K.M. Befus, G.N. Flerchinger, M.S. Seyfried, B.J. Carr, 2025, Hydrogeophysical inversion using a physics-based catchment model with hydrological and electromagnetic induction data. Journal of Hydrology 647, 132376.

Smith, E., B. Carr, 2024, Defining hydrogeophysical layers with multi-scale geophysics for increased understanding of mountain basin recharge. Journal of Geophysical Research: Solid Earth 129 (10), e2024JB029069.

Phillips, S.N., B. Carr, Y. Zhang, B. Flinchum, S. Ren, 2024, Borehole Nuclear Magnetic Resonance estimation of Specific Yield in a fractured granite aquifer. Groundwater 62 (4), 578-590.

Uhlemann, S., L. Peruzzo, C. Chou, K.H. Williams, S. Wielandt, C. Wang, N. Falco, Y. Wu, B. Carr, P. Meldrum, J. Chambers, B. Dafflon, 2024, Variations in bedrock and vegetation cover modulate subsurface water flow dynamics of a mountainous hillslope. Water Resources Research 60 (2), e2023WR036137.              

Flinchum, B.A., D. Grana, B.J. Carr, N. Ravichandran, B. Eppinger, W.S. Holbrook, 2024, Low Vp/Vs values as an indicator for fractures in the critical zone. Geophysical Research Letters 51 (2), e2023GL105946.

Sturm, S., F. Carboni, I. Wieck, T. Kenkmann, D.J. Cook, A. Fraser, K.A. Sundell, B. Carr, 2024, Comprehensive tructural and petrographic analyses of drill core samples from the center and rim of the small (60 x 41 m) impact crater SM-1 of the Wyoming crater field, USA. 20th Symposium Tectonics, Structural Geology and Geology of Crystalline Rocks, ID 122.

Li, A., Grana, D., A.D. Parsekian, B.J. Carr, 2024, Uncertainty quantification in tomographic inversion of Near-Surface refraction data. Mathematical Geosciences 56 (1), 77-101.

Kenneth WW Sims, K.W.W, C.M. Messa, S.R. Scott, A.D. Parsekian, A. Miller, A.L. Role, T.P. Moloney, E.L. Shock, J.B. Lowenstern, R.B. McCleskey, M.A. Charette, B.J. Carr, S. Pasquet, H. Heasler, C. Jaworowoski, W.S. Holbrook, M.R. Lindsay, D.R. Colman, E.S. Boyd, 2023, The dynamic influence of subsurface geological processes on the assembly and diversification of thermophilic communities in continental hydrothermal systems. Geochimica et Cosmochimica Acta 362, 77-103.

Rachel Kaitlyn Uecker, R.K., B.A. Flinchum, W.S. Holbrook, B.J. Carr, 2023, Mapping bedrock topography: A seismic refraction survey and landscape analysis in the Laramie Range, Wyoming. Frontiers in Water 5, 1057725.

Ciraula, D.A., B.J. Carr, K.W.W. Sims, 2023, Time-Lapse geophysical investigation of geyser dynamics at Spouter Geyser, Yellowstone National Park: Geyser Dynamics II. Journal of Geophysical Research: Solid Earth 128 (2), e2022JB024426.

Ciraula, D.A., B.J. Carr, K.W.W. Sims, 2023, Geophysical imaging of the shallow geyser and hydrothermal reservoir structures of Spouter Geyser, Yellowstone National Park: Geyser Dynamics I. Journal of Geophysical Research: Solid Earth 128 (2), e2022JB024417.

Grana, D., A.D. Parsekian, B.A. Flinchum, R.P. Callahan, N.Y. Smeltz, A. Li, J.L. Hayes, B.J. Carr, K. Singha, C.S. Riebe, W.S. Holbrook, 2022, Geostatistical rock physics inversion for predicting the spatial distribution of porosity and saturation in the critical zone. Mathematical Geosciences 54 (8), 1315-1345.

Smeltz, N.Y., K.W.W. Sims, B.J. Carr, A.D. Parsekian, 2022, Geologic controls on hydrothermal groundwater mixing in Yellowstone National Park. Journal of Volcanology and Geothermal Research 431, 107650.

Pertermann, D.L., B.J. Carr, 2022, To Preserve the Struggle: Digitizing the Oregon Trail. Historical Archaeology 56 (3), 407-416.

Smith, E., B. Carr, 2022, Integrated geophysical imaging and hydrologic modeling of mountain block recharge pathways. Frontiers in Hydrology 2022, 102-01.

Ball, L.B., A.H. Manning, B. Carr, J.L. Mauk, 2022, Geologic controls on bedrock permeability in a mineralized, sedimentary rock alpine watershed. Frontiers in Hydrology 2022, 305-02A.

Uhlemann, S., B. Dafflon, H.M. Wainwright, K.H. Williams, B. Minsley, K. Zamudio, B. Carr, N. Falco, C. Ulrich, S. Hubbard, 2022, Surface parameters and bedrock properties covary across a mountainous watershed: Insights from machine learning and geophysics. Science Advances 8 (12), eabj2479.

Flinchum, B.A., W.S. Holbrook, B.J. Carr, 2022, What do P-wave velocities tell us about the critical zone? Frontiers in Water 3, 772185.

Eppinger, B.J., J.L. Hayes, B.J. Carr, S. Moon, C.L. Cosans, W.S. Holbrook, C.J. Harman, Z.T. Plante, 2021, Quantifying depth-dependent seismic anisotropy in the critical zone enhanced by weathering of a piedmont schist. Journal of Geophysical Research: Earth Surface 126 (10), e2021JF006289.

Ma, L., D. Oakley, A. Nyblade, S. Moon, N. Accardo, W. Wang, X. Gu, K. Brubaker, G.J. Mount, B. Forsythe, B.J. Carr, S. L. Brantley, 2021, Seismic imaging of a shale landscape under compression shows limited influence of topography-induced fracturing. Geophysical Research Letters 48 (17), e2021GL093372.

Ren S., Y. Zhang, J. Yeh, Y. Wang, B.J. Carr, 2021, Multiscale hydraulic conductivity characterization in a fractured granitic aquifer: The evaluation of scale effect. Water Resources Research 57 (9), e2020WR028482

Riebe, C.S., R.P. Callahan, S.B.M. Granke, B.J. Carr, J.L. Hayes, MS Schell, L.S. Sklar, 2021, Anisovolumetric weathering in granitic saprolite controlled by climate and erosion rates. Geology, DOI: 10.1130/G48191.1.

Leone, J.D., W.S. Holbrook, C.S. Riebe, J. Chorover, T.P. Ferre, B.J. Carr, R.P. Callahan, 2020, Strong slope-aspect control of regolith thickness by bedrock foliation. Earth Surface Processes and Landforms, DOI: 10.1002/esp.4947.

Callahan, R.P., C.S. Riebe, S. Pasquet, KL Ferrier, D. Grana, L.S. Sklar, N.J.Taylor, B.A. Flinchum, J.L. Hayes, B.J. Carr, P.C. Hartsough, A.T. O’Green, W.S. Holbrook, 2020, Subsurface weathering Revealed in Hillslope-Integrated Porosity Distributions. Geophysical Research Letters, DOI: 10.1029/2020GL088322.

Gu, X., G. Mavko, L. Ma, D. Oakley, N. Accardo, B.J. Carr, A.A. Nyblade, S.L. Brantley, 2020, Seismic refraction tracks porosity generation and possible CO2 production at depth under a headwater catchment. Proceedings of the National Academy of Sciences, DOI: 10.1073/pnas.2003451117.

Moravec, B.G., A.M. White, R.A. Root, A. Sanchez, Y. Olshansky, B.K. Paras, B.J. Carr, J. McIntosh, J.D. Pelletier, C. Rasmussen, W. S. Holbrook, J. Chorover, 2020, Resolving deep critical zone architecture in complex volcanic terrain. Journal of Geophysical Research: Earth Surface, DOI: 10.1029/2019JF005189.

Holbrook, W.S., V. Marcon, A.R. Bacon, S.L. Brantley, B.J. Carr, B.A. Flinchum, D.D. Richter, C.S. Riebe, 2019, Links between physical and chemical weathering inferred from a 65-m-deep borehole through Earth’s critical zone. Scientific Reports, DOI: 10.1038/s41598-019-40819-9.

Ren, S., A.D. Parsekian, Y. Zhang, B.J. Carr, 2019, Hydraulic conductivity calibration of logging NMR in a granite aquifer, Laramie Range, Wyoming. Groundwater, DOI: 10.1111/gwat.12798.

Carey, A.M., G.B. Paige, B.J. Carr, W.S. Holbrook, S.N. Miller, 2019, Characterizing hydrological processes in a semiarid rangeland watershed: A hydrogeophysical approach. Hydrological Processes, DOI: 10.1002/hyp.13361.

Flinchum, B.A., W.S. Holbrook, A.D. Parsekian, B.J. Carr, 2019, Characterizing the critical zone using borehole and surface nuclear magnetic resonance. Vadose Zone Journal, DOI: 10.2136/vzj2018.12.0209.

Carey, A.M., Paige, G.B., Carr, B.J., and M. Dogan, 2017, Forward modeling to investigate inversion artifacts resulting from surface electrical resistivity tomography during rainfall events. Journal of Applied Geophysics, 145, 39-49.

Pasquet, S., W.S. Holbrook, B.J. Carr, K. W.W. Sims, 2016, Geophysical Imaging of Shallow Degassing in a Yellowstone hydrothermal system, Geophysical Research Letters, 43 (23), 1-9, DOI: 10.1002/2016GL071306

St. Clair, J., Moon, S., Holbrook, W.S., Perron, J.T., Riebe, C.S., Martel, S.J., Carr, B.J., Harman, C., Singha, K., and D. DeB. Richter, 2015. Geophysical imaging reveals topographic stress controls of bedrock weathering: Science, 30 Oct 2015, Vol. 350, Issue 6260, pp. 534-538, DOI: 10.1126/science.aab2210.

Carr, B.J., Lagmanson, M. M. and H. Aktaracki, 2011. The Use of Electrical Imaging to Characterize Contaminated Sites: Geophysical Transactions, Vol. 45, No. 4, pp. 223-231.

Doll, W.E., Carr, B.J. and J.R. Sheehan, and W.A. Mandell, 2005. Overview of Karst Effects and Karst Detection in Seismic Data from the Oak Ridge Reservation, Tennessee: U.S. Geological Survey Karst Interest Group Proceedings, Rapid City, South Dakota, September 12-15, 2005, Scientific Investigations Report: 2005-516, 20-28.

Miller, R.D., Hunter, J.A., Doll, W.E., Carr, B.J., and T.S. Collett, 2004, High-resolution seismic imaging of the hydrate stability zone at the Mallik L-38 research site, Northwest Territories, Canada: Geological Survey of Canada Bulletin 585, 14p.

Nyquist, J. E., Carr, B. J., and R. K. Davis, 1999. DC Resistivity Monitoring of Potassium Permanganate Injected to Oxidize TCE In Situ: Journal of Environmental and Engineering Geophysics, vol. 4, 135-148.

Carr, B. J., and Z. Hajnal, 1999. P- and S-Wave Characterization of Near-Surface Reflectivity from Glacial Tills Using Vertical Seismic Profiles: Geophysics, vol.64, 970-980.

Carr, B. J., Hajnal, Z., and A. Prugger, 1998. Shear Wave Studies in Glacial Till: Geophysics, vol. 63, 1273-1284.

Carr, B.J., Smithson, S. B., Kareav, N., Ronin, A., Garipov, V., Kristofferson, Y., Digranes, P., Smythe, D., and C. Gillen, 1996. Vertical Seismic Profile Results from the Kola Superdeep Borehole, Russia: Tectonophysics, vol. 264, 295-307.