Michelle Walvoord


Michelle Walvoord is a Research Hydrologist in the Water Cycle Branch of the Earth System Processes Division of the Water Resources Mission Area. Her areas of expertise include permafrost hydrology, unsaturated zone and groundwater hydrology, and non-isothermal, multiphase flow and transport modeling. Her current research activities are aimed at better understanding environmental impacts on hydrologic systems undergoing change in northern high latitudes. She serves as an Associate Editor for Water Resources Research and as a science steering member the Permafrost Action Team for NSF's SEARCH project. Michelle is an adjunct faculty member at Colorado School of Mines in the Geology and Geological Engineering Department. 


  • Ph.D. in Earth and Environmental Science, New Mexico Tech
  • M.S.  in Hydrology, New Mexico Tech
  • B.A.  in Geology, Hamilton College


  • 2017 - present: Research Hydrologist and Team Lead, USGS Earth System Processes Division, Denver, CO
  • 2004 - 2017: Research Hydrologist, USGS National Research Program, Denver, CO
  • 2002 - 2004: National Academy of Sciences Postdoctoral Research Associate, USGS National Research Program, Denver, CO 


  • Outstanding Woman in Science Award, Geological Society of America, 2005
  • Langmuir Award for Excellence in Research, New Mexico Tech, 2004


Rey, D, Walvoord, M, Ebel, B, Minsley, B, Voss, C, Singha, K. (2020) Wildfire-initiated talik development exceeds current thaw projections: Observations and models from Alaska's continuous permafrost zone. Geophysical Research Letters. https://doi.org/10.1029/2020GL087565

Tank, SE, Vonk, JE, Walvoord, MA, McClelland, JW, Laurion, I, Abbott, BW. (2020) Landscape matters: Predicting the biogeochemical effects of permafrost thaw on aquatic networks with a state factor approach. Permafrost and Periglacial Processes. 1– 13. https://doi.org/10.1002/ppp.2057

Walvoord, MA, Voss, CI, Ebel, BA, Minsley, BJ. (2019) Development of perennial thaw zones in boreal hillslopes enhances potential mobilization of permafrost carbon. Environmental Research Letters. 14 (1) https://doi.org/10.1088/1748-9326/aaf0cc    

Vonk, JE, Tank, SE, Walvoord, MA. (2019) Integrating hydrology and biogeochemistry across frozen landscapes. Nature Communications. 10: 5377. https://doi.org/10.1038/s41467-019-13361-5

Rey, DM, Walvoord, M, Minsley, B, Rover, J, Singha, K. (2019) Investigating lake-area dynamics across a permafrost-thaw spectrum using airborne electromagnetic surveys and remote sensing time-series data in Yukon Flats, Alaska. Environmental Research Letters. 14 (2). https://doi.org/10.1088/1748-9326/aaf06f

Ebel, BA, Koch, J, Walvoord, MA. (2019) Soil physical, hydraulic, and thermal properties in Interior Alaska, USA: Implications for hydrologic response to thawing permafrost conditions. Water Resources Research. 55: 4427-4447. https://doi.org/10.1029/2018WR023673

Conaway, CH, Walvoord, M, Thomas, RB, Green, CT, Baker, RJ, Thordsen, JJ, Stonestrom, DA, Andraski, BJ. (2018) Unsaturated zone CO2, CH4, and δ13C-CO2 at an arid region low-level radioactive waste disposal site. Vadose Zone Journal. 17:170200. https://doi.org/10.2136/vzj2017.11.0200

Briggs, MA, Campbell, S, Nolan, J, Walvoord, MA, Ntarlagiannis, D, Day-Lewis, FD, Lane JW. (2017) Surface geophysical methods for characterizing frozen ground in transitional permafrost landscapes. Permafrost and Periglacial Processes. 28:52-65. https://doi.org/10.1002/ppp.1893

Walvoord, MA, Kurylyk, BL. (2016) Hydrologic impacts of thawing permafrost – a review, Vadose Zone Journal. 15:6. https://doi.org/10.2136/vzj2016.01.0010

Meixner, T, Manning, AH, Stonestrom, DA, Allen, DM,  Ajami, H, Blasch, KW, Brookfield, AE,  Castro, CI, Clark, JF, Gochis, DJ, Fint, AL, Neff, KL, Niraula, R, Rodell, M, Scanlon, BR, Singha, K, and  Walvoord, MA. (2016) Implications of projected climate change for groundwater recharge in the western United States. Journal of Hydrology. 534:124-138. https://doi.org/10.1016/j.jhydrol.2015.12.027

Jepsen, SM, Walvoord MA, Voss, CI, Rover, J. (2016) Effect of permafrost thaw on the dynamics of lakes recharged by ice-jam floods: case study of Yukon Flats, Alaska. Hydrological Processes. 30: 1782-1795. https://doi.org/10.1002/hyp.10756

Walvoord, MA, Day-Lewis, FD, Lane, JW, Striegl, RG, Voss, CI, Douglas, T. (2015) Improved understanding of permafrost controls on hydrology in interior Alaska by integration of ground-based geophysical permafrost characterization and numerical modeling, Final Report: DTIC Document, v. SERDP Project RC-2111, ADA621851, 111 p.

Minsley, BJ, Wellman, TP, Walvoord, MA, Revil, A. (2015) Sensitivity of airborne geophysical data to sublacustrine and near-surface permafrost thaw. The Cryosphere. 9:781-794. https://doi.org/10.5194/tc-9-781-2015

Green, CT, Walvoord, MA, Andraski, BJ, Striegl, RG, Stonestrom, DA. (2015) Multimodel analysis of anisotropic diffusive tracer-gas transport in a deep arid unsaturated zone, Water Resources Research. 51:8 https://doi.org/10.1002/2014WR016055

Walvoord, MA, Andraski, B, Green, CT, Stonestrom, D, Striegl, R. (2014) Field-scale sulfur hexafluoride tracer experiment to understand long distance gas transport in the deep unsaturated zone. Vadose Zone Journal. 13: (8) https://doi.org/10.2136/vzj2014.04.0045

Pastick, NJ, Jorgenson, MT, Wylie, BK, Rose, JR, Rigge, M, Walvoord, MA. (2014) Spatial variability and landscape controls of near-surface permafrost within the Yukon River Basin, Journal of Geophysical Research – Biogeosciences. 119:1244-1265. https://doi.org/10.1002/2013JG002594

O'Donnell, JA, Aiken, GR, Walvoord, MA, Raymond, PA, Butler, KD, Dornblaser, MM, Heckman K. (2014) Using dissolved organic matter age and composition to detect permafrost thaw in boreal watersheds of interior Alaska. Journal Geophysical Research – Biogeosciences. 119:2155-2170. https://doi.org/10.1002/2014JG002695

Minsley, BJ, Wellman TP, Walvoord, MA, Revil A. (2014) Modeling the hydrogeophysical response of lake talik evolution, SEG Technical Program Expanded Abstracts 2014: 4528-4533. https://doi.org/10.1190/segam2014-0311.1

Briggs, MA, Walvoord, MA, McKenzie, JM, Voss, CI, Day-Lewis, FD, Lane JW. (2014) New permafrost is forming around shrinking arctic lakes, but will it last? Geophysical Research Letters. 41:1585-1592. https://doi.org/10.1002/2014GL059251

Wellman, TP, Voss, CI, Walvoord, MA. (2013) Impacts of climate, lake size, and supra- and sub-permafrost groundwater flow on lake-talik evolution, Yukon Flats, Alaska, USA. Hydrogeology Journal. 21(1) 281-298. https://doi.org/10.1007/s10040-012-0941-4

Pastick, NJ, Jorgenson MT, Wylie, BK, Minsley, BJ, Ji, L, Walvoord, MA, Smith, BD, Abraham, JD, Rose, JR. (2013). Extending airborne electromagnetic surveys for regional active layer and permafrost mapping with remote sensing and ancillary data, Yukon Flats Ecoregions, Central Alaska. Permafrost and Periglacial Processes. 24, 184:199. https://doi.org/10.1002/ppp.1775

Jepsen, SM, Voss, CI, Walvoord, MA, Minsley, BJ, Rover, J. (2013). Linkages between lake shrinkage/expansion and sublacustrine permafrost distribution determined from remote sensing of Interior Alaska, USA. Geophysical Research Letters. 40:882-887. https://doi.org/10.1002/grl.50187

Jepsen, SM, Voss, CI, Walvoord, MA, Rose, JR, Minsley, BJ, Smith, BD. (2013) Sensitivity analysis of lake mass balance in discontinuous permafrost: the example of disappearing Twelvemile Lake, Yukon Flats, Alaska (USA). Hydrogeology Journal. 21:185-200. https://doi.org/10.1007/s10040-012-0896-5

Walvoord, MA, Voss, CI, Wellman TP. (2012) Influence of permafrost distribution on groundwater flow in the context of climate-change-driven permafrost thaw: Example from Yukon Flats Basin, Alaska, USA. Water Resources Research. 48(7): W07524. https://doi.org/10.1029/2011WR011595

O'Donnell, JA, Aiken, GR, Walvoord, MA, Butler, KD. (2012) Dissolved organic matter composition of winter stream flow in the Yukon River basin: implications of permafrost thaw and increased groundwater discharge. Global Biogeochemical Cycles. 26: GB0E06. https://doi.org/10.1029/2012GB004341

Minsley, BJ, Abraham, JD, Smith BD, Cannia, JC, Voss, CI, Jorgenson, MT, Walvoord, MA, Wylie, BK,  Anderson, L, Ball LB, Deszcz-Pan, M, Wellman, TP, Ager T. (2012). Airborne geophysical mapping of discontinuous permafrost in the Yukon Flats, Alaska. Geophysical Research Letters. 39, L02503. https://doi.org/10.1029/2011GL050079

Jepsen, SM, Koch, J, Rose, J, Voss, CI, Walvoord, MA. (2012) Thermal and hydrological observations near Twelvemile Lake in discontinuous permafrost, Yukon Flats, interior Alaska, September 2010 - August 2011. U.S. Geol. Surv. Open File Report 2012-1121, 25 p.

Walvoord, M, Schuster, P, Striegl, R. (2009), Understanding the effects of climate change in the Yukon River Basin through a synergistic research approach, in Planning for an uncertain future—Monitoring, integration, and adaptation. Proceedings of the Third Interagency Conference on Research in the Watersheds, Webb, R.M.T., and Semmens, D.J., eds., U.S. Geological Survey Scientific Investigations Report 2009-5049.

Brabets, TP, Walvoord, MA. (2009) Trends in streamflow in the Yukon River Basin from 1944 to 2005 and the influence of the Pacific Decadal Oscillation. Journal of Hydrology. 371, 108-119. https://doi.org/10.1016/j.jhydrol.2009.03.018

Walvoord, MA, Andraski, BJ, Krabbenhoft, DP, Striegl, RG. (2008) Transport of elemental mercury in the unsaturated zone from a waste disposal site in an arid region. Applied Geochemistry. 23: 572–583. https://doi.org/10.1016/j.apgeochem.2007.12.014

Gurdak, JJ, Walvoord, MA, McMahon, PJ. (2008) Susceptibility to enhanced chemical migration from depression-focused preferential flow, High Plains aquifer. Vadose Zone Journal. 7(4): 1218–1230. https://doi.org/10.2136/vzj2007.0145

Amundson, R, Ewing, S, Dietrich, W, Sutter, B, Owen, J, Chadwick, O, Nishiizumi, K, Walvoord, M, McKay, C. (2008) On the in situ alteration of soils on Mars. Geochimica et Cosmochimica Acta. 72:3845-3864. https://doi.org/10.1016/j.gca.2008.04.038

Walvoord, M, Striegl, R. (2007) Increased groundwater to stream discharge from permafrost thawing in the Yukon River basin: Potential impacts on lateral export of carbon and nitrogen. Geophysical Research Letters. 34: L12402. https://doi.org/10.1029/2007GL030216

Stonestrom, DA, Prudic, DE, Walvoord, MA, Abraham, JA, Stewart-Deaker, AE, Glancy, PA, Constantz, J, Laczniak, RJ, Andraski, BJ. (2007) Focused ground-water recharge in the Amargosa Desert Basin, in Ground-water Recharge in the Arid and Semi-arid Southwestern United States. Edited by D.A. Stonestrom et al., USGS Professional Paper 1703, p. 107-136.

Rao, B, Anderson, T, Orris, G, Rainwater, KA, Rajagopalan, S, Sandvig, R, Scanlon, B, Stonestrom, D, Walvoord, M, Jackson, W.A. (2007) Widespread natural perchlorate in unsaturated zones of the southwest United States. Environmental Science and Technology. https://doi.org/10.1021/es062853i

Michel, R, Schuster, P, Walvoord, M. (2007) Tritium concentrations in the Yukon River Basin and their implications, in Proceedings of the International Symposium on Advances in Isotope Hydrology and its role in Sustainable Water Resources Management, p. 487-492, IAEA, Vienna, Austria.

Kwicklis, E, Wolfsberg, A, Stauffer, P, Walvoord, M, Sully, M. (2006). Multiphase, multicomponent parameter estimation for liquid and vapor fluxes in deep arid systems using hydrologic data and natural environmental tracers. Vadose Zone Journal. 5: 934-950.  https://doi.org/10.2136/vzj2006.0021

Walvoord, MA, Striegl, RG, Prudic, DE, Stonestrom, DA. (2005) CO2 dynamics in the Amargosa Desert: Fluxes and isotopic speciation in a deep unsaturated zone. Water Resources Research. 41(2). https://doi.org/10.1029/2004WR003599

Seyfried, M, Schwinning, S, Walvoord, M, Pockman, W, Jackson, R, Newman, B, Phillips, F. (2005). Ecohydrological control of deep drainage in semiarid regions. Ecology. 86 (2): 277-287. https://doi.org/10.1890/03-0568

Walvoord, MA, Stonestrom, DA, Andraski, BJ, Striegl RG. (2004) Constraining the inferred paleohydrologic evolution of a deep unsaturated zone in the Amargosa Desert. Vadose Zone Journal. 3: 502-512. https://doi.org/10.2136/vzj2004.0502

Walvoord, MA, Stonestrom DA. (2004) Enhanced gas-phase transport in a deep unsaturated zone, Amargosa Desert (U.S.A), in Proceedings of the International Conference on Finite Element Models, MODFLOW, and More: Solving Groundwater Problems, edited by K. Kovar, Z. Hrkal, and J. Bruthans, pp. 227-230, IAHS, Karlovy Vary, Czech Republic.

Walvoord, MA, Scanlon BR. (2004) Hydrologic processes in deep vadose zones in interdrainage arid environments, in Groundwater Recharge in a Desert Environment---The Southwestern United States, edited by J.F. Hogan, F.M. Phillips, and B.R. Scanlon, Water Science and Applications Series, vol. 9, American Geophysical Union, Washington, D.C., 15-28.

Walvoord, MA, Phillips FM. (2004) Identifying areas of basin-floor recharge in the Trans-Pecos region and the link to vegetation. Journal of Hydrology 292: 59-74.  https://doi.org/10.1016/j.jhydrol.2003.12.029

Walvoord, MA, Phillips, FM, Stonestrom DA, Evans RD, Hartsough PC, Newman, BD, Striegl RG. (2004) Response to Comment on “A reservoir of nitrate beneath desert soils, Science, 304, 51, doi: 10.1126/science.1095033.

Stonestrom, DA, Abraham JD, Andraski BJ, Baker RJ, Mayers CJ, Michel RL, Prudic DE, Striegl RG, Walvoord MA. (2004) Monitoring radionuclide contamination in the unsaturated zone - lessons learned at the Amargosa Desert Research Site, Nye County, Nevada, in Proceedings of the Workshop on Long-term Performance Monitoring of Metals and Radionuclides in the Subsurface, Reston, VA, April 21-22, 2004: Tallahassee, Florida State University, 6 pages.

Phillips, FM, Walvoord, MA, Small EE. (2004) Effects of environmental change on groundwater recharge in the Desert Southwest, in Groundwater Recharge in a Desert Environment: The Southwestern United States, edited by J.F. Hogan, F.M. Phillips, and B.R. Scanlon, Water Science and Applications Series, vol. 9, American Geophysical Union, Washington, D.C., 273-294.

Walvoord, MA, Phillips, FM, Stonestrom, DA, Evans, RD, Hartsough, PC, Newman, BD, Striegl RG. (2003) A reservoir of nitrate beneath desert soils. Science. 302:1021-1024. DOI: 10.1126/science.1086435

Walvoord, MA, Phillips, FM. (2003) Water movement through deep arid vadose zones: In Understanding water in a dry environment: Hydrological processes in arid and semi-arid zones (Simmers, I., ed.), A.A. Balkema, Lisse, pp. 195-202.

Walvoord, MA, Plummer, MA, Phillips, FM, Wolfsberg, AV. (2002) Deep arid system hydrodynamics 1: Equilibrium states and response times in thick desert vadose zones. Water Resources Research. 38: 1308. https://doi.org/10.1029/2001WR000824

Walvoord, MA, Phillips, FM, Tyler, SW, Hartsough, PC. (2002) Deep arid system hydrodynamics 2: Application to paleohydrologic reconstruction using vadose-zone profiles from the northern Mojave Desert. Water Resources Research. 38: 1291. https://doi.org/10.1029/2001WR000825

Walvoord, MA. (2002) A unifying conceptual model to describe water, vapor, and solute transport in deep arid vadose zones, PhD Thesis, Earth and Environmental Science Department, New Mexico Institute of Mining and Technology, Socorro, New Mexico.

Hartsough PC, Tyler, SW, Sterling, J, Walvoord, MA. (2001). A 14.6 kyr record of nitrogen flux from desert soil profiles as inferred from vadose zone pore waters. Geophysical Research Letters. 28:15, 2955 - 2958. https://doi.org/10.1029/2000GL011823

Walvoord, M, Pegram, P, Phillips, F, Person, M, Kieft, T, Fredrickson, J, McKinley, J, Swenson J. (1999) Groundwater flow and geochemistry in the southeastern San Juan Basin: Implications for microbial transport and activity. Water Resources Research. 35, 1409. https://doi.org/10.1029/1999WR900017