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.
EDUCATION
PROFESSIONAL APPOINTMENTS
PROFESSIONAL AWARDS
PUBLICATIONS
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
ABoVE: Vulnerability of inland waters and the aquatic carbon cycle to changing permafrost and climate across boreal northwestern North America.
Carbon released from thawing permafrost may fuel terrestrial and aquatic ecosystems or contribute to greenhouse gas emission, leading to a potential warming feedback and further thaw.
Groundwater withdrawals in the western US are a critical component of the water resources strategy for the region. Climate change already may be substantially altering recharge into groundwater systems; however, the quantity and direction (increase or decrease) of changes are relatively unknown as most climate change assessments have focused on surface water systems. We propose to conduct a...
Research has traditionally focused on atmospheric release of carbon from thawing permafrost, yet overlooked waterborne release pathways likely contribute significantly, especially in a warming Arctic. To address this knowledge gap and better constrain the fate of carbon in the North, we recommend inter-disciplinary efforts bridging physical,...
Jorien Vonk; Suzanne Tank; Walvoord, Michelle Ann Boreal forest regions are a focal point for investigations of coupled water and biogeochemical fluxes in response to wildfire disturbances, climate warming, and permafrost thaw. Soil hydraulic, physical, and thermal property measurements for mineral soils in permafrost regions are limited, despite substantial influences on cryohydrogeologic model...
Ebel, Brian A.; Koch, Joshua C.; Walvoord, Michelle A. Lakes in boreal lowlands cycle carbon and supply an important source of freshwater for wildlife and migratory waterfowl. The abundance and distribution of these lakes are supported, in part, by permafrost distribution, which is subject to change. Relationships between permafrost thaw and lake dynamics remain poorly known in most boreal regions....
Rey, David; Walvoord, Michelle Ann; Minsley, Burke; Rover, Jennifer; Singha, Kamini Permafrost thaw alters subsurface flow in boreal regions that in turn influences the magnitude, seasonality, and chemical composition of streamflow. Prediction of these changes is challenged by incomplete knowledge of timing, flowpath depth, and amount of groundwater discharge to streams in response to thaw. One important phenomenon that may...
Walvoord, Michelle A.; Voss, Clifford I.; Ebel, Brian A.; Minsley, Burke J. Elevated tritium, radiocarbon, Hg, and volatile organic compounds associated with low-level radioactive waste (LLRW) at the USGS Amargosa Desert Research Site (ADRS) have stimulated research on factors and processes that affect contaminant gas distribution and transport. Consequently, we examined the sources, mixing, and biogeochemistry of CO2...
Conaway, Christopher H.; Walvoord, Michelle Ann; Thomas, Randall B.; Green, Christopher; Baker, R.J.; Thordsen, James J.; Stonestrom, David A.; Andraski, Brian J. The distribution of shallow frozen ground is paramount to research in cold regions, and is subject to temporal and spatial changes influenced by climate, landscape disturbance and ecosystem succession. Remote sensing from airborne and satellite platforms is increasing our understanding of landscape-scale permafrost distribution, but typically...
Briggs, Martin A.; Campbell, Seth; Nolan, Jay; Walvoord, Michelle Ann; Ntarlagiannis, Dimitrios; Day-Lewis, Frederick D.; Lane, John W. Understanding the role of permafrost in controlling groundwater flow paths and fluxes is central in studies aimed at assessing potential climate change impacts on vegetation, species habitat, biogeochemical cycling, and biodiversity. Recent field studies in interior Alaska show evidence of hydrologic changes hypothesized to result from permafrost...
Walvoord, Michelle Ann; Voss, Clifford I.; Wellman, Tristan Existing studies on the impacts of climate change on groundwater recharge are either global or basin/location-specific. The global studies lack the specificity to inform decision making, while the local studies do little to clarify potential changes over large regions (major river basins, states, or groups of states), a scale often important in...
Meixner, Thomas; Manning, Andrew H.; Stonestrom, David A.; Allen, Diana M.; Ajami, Hoori; Blasch, Kyle W.; Brookfield, Andrea E.; Castro, Christopher L.; Clark, Jordan F.; Gochis, David; Flint, Alan L.; Neff, Kirstin L.; Niraula, Rewati; Rodell, Matthew; Scanlon, Bridget R.; Singha, Kamini; Walvoord, Michelle Ann Where present, permafrost exerts a primary control on water fluxes, flowpaths, and distribution. Climate warming and related drivers of soil thermal change are expected to modify the distribution of permafrost, leading to changing hydrologic conditions, including alterations in soil moisture, connectivity of inland waters, streamflow seasonality,...
Walvoord, Michelle Ann; Kurylyk, Barret L. Background Our research encompasses a broad spectrum of water resources concerns deriving from climate and disturbance effects. We investigate water, gas, solute, and energy transport in climates ranging from subarctic to arid to equatorial at sites located within the US and internationally. Selected current research topics include: vulnerability...
Walvoord, Michelle Ann; Ebel, Brian A.; Tindall, James A. Large river floods are a key water source for many lakes in fluvial periglacial settings. Where permeable sediments occur, the distribution of permafrost may play an important role in the routing of floodwaters across a floodplain. This relationship is explored for lakes in the discontinuous permafrost of Yukon Flats, interior Alaska, using an...
Steve M. Jepsen; Walvoord, Michelle Ann; Voss, Clifford I.; Rover, Jennifer R. Gas transport in the unsaturated zone affects contaminant flux and remediation, interpretation of groundwater travel times from atmospheric tracers, and mass budgets of environmentally important gases. Although unsaturated zone transport of gases is commonly treated as dominated by diffusion, the characteristics of transport in deep layered...
Green, Christopher T.; Walvoord, Michelle Ann; Andraski, Brian J.; Striegl, Robert G.; Stonestrom, David A.