Michelle Walvoord
(She/her)Michelle Walvoord is a Research Hydrologist in the Earth System Processes Division of the Water Resources Mission Area.
Dr. Michelle A. Walvoord is a hydrogeologist whose current research focuses on understanding hydrologic response to climate change and wildfire disturbance. With expertise in non-isothermal, multiphase subsurface flow and transport, she has led a variety of process-based vadose zone and groundwater studies in systems ranging from mid-latitude deserts to high-latitude boreal forests. Her research relies on a blend of field, statistical, and physics-based modeling approaches and typically intersects with multiple disciplines including biogeochemistry, ecology, and geophysics.
Professional Experience
Research Hydrologist, USGS Earth System Processes Division, Denver, CO (2017 – present)
Research Hydrologist, USGS National Research Program, Denver, CO (2004-2017)
National Academy of Sciences Postdoctoral Research Associate, Denver, CO (2002-2004)
Education and Certifications
Ph.D. in Earth and Environmental Science, New Mexico Tech
M.S. in Hydrology, New Mexico Tech
B.A. in Geology, Hamilton College
Affiliations and Memberships*
Affiliate Faculty, Geology and Geological Engineering Dept., Colorado School of Mines (2016 – present)
Graduate Faculty Appointment, Geological Sciences Dept., University of Colorado, Boulder (2016 – present)
Associate Faculty, Université Laval (2021 – present)
Member of the USGS Water Mission Area’s Diversity, Equity, Inclusion, and Accessibility Employee Leadership Team (2022-present)
Member of the American Geophysical Union Hydrology Section’s Justice, Equity, Diversity, and Inclusion committee (2021-present)
Board of Directors, United States Permafrost Association (2021-2022)
Associate Editor, Water Resources Research (2015 – present)
Associate Editor, Hydrogeology Journal (2014-2017)
Member of the Terrestrial Multidisciplinary distributed Observatories for the Study of Arctic Connection (t-MOSAIC) Land-Water Processes Action Group (2019 – present)
Science Steering Committee, Permafrost Action Team for the National Science Foundation’s Study of Environmental Arctic Change Project (SEARCH) (2015 – present)
Science Advisory Board, USGS Powell Center for Analysis and Synthesis (2015 – 2019)
Honors and Awards
Woo Distinguished Lecture in Hydrology, Canadian Geophysical Union, 2022
Outstanding Woman in Science Award, Geological Society of America, 2005
Langmuir Award for Excellence in Research, New Mexico Tech, 2004
Science and Products
Filter Total Items: 66
Multi-scale geophysical mapping of deep permafrost change after disturbance in interior Alaska, USA
Disturbance related to fire or hydrologic processes can cause degradation of deep (greater than 1 m) permafrost. These changes in deep permafrost have the potential to impact landscapes and infrastructure, alter the routing and distribution of surface water or groundwater, and may contribute to the flux of carbon to terrestrial and aquatic ecosystems. However, characterization of deep permafrost o
Authors
Burke J. Minsley, Benjamin R. Bloss, Brian A. Ebel, David Matthew Rey, Michelle A. Walvoord, Dana R.N. Brown, Ronald Daanen, Abraham M. Emond, M. Andy Kass, Neal J. Pastick, Bruce Wylie
Unsaturated zone CO2, CH4, and δ13C-CO2 at an arid region low-level radioactive waste disposal site
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 and CH4, two additional important species in the unsat
Authors
Christopher H. Conaway, Michelle Ann Walvoord, Randall B. Thomas, Christopher Green, R.J. Baker, James J. Thordsen, David A. Stonestrom, Brian J. Andraski
Surface geophysical methods for characterising frozen ground in transitional permafrost landscapes
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 lacks the resolution to characterise finer-scale proces
Authors
Martin A. Briggs, Seth Campbell, Jay Nolan, Michelle Ann Walvoord, Dimitrios Ntarlagiannis, Frederick D. Day-Lewis, John W. Lane
Hydrologic impacts of thawing permafrost—A review
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, and the partitioning of water stored above and belo
Authors
Michelle Ann Walvoord, Barret L. Kurylyk
Implications of projected climate change for groundwater recharge in the western United States
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 the development of water policy. An analysis of the p
Authors
Thomas Meixner, Andrew H. Manning, David A. Stonestrom, Diana M. Allen, Hoori Ajami, Kyle W. Blasch, Andrea E. Brookfield, Christopher L. Castro, Jordan F. Clark, David Gochis, Alan L. Flint, Kirstin L. Neff, Rewati Niraula, Matthew Rodell, Bridget R. Scanlon, Kamini Singha, Michelle Ann Walvoord
Effect of permafrost thaw on the dynamics of lakes recharged by ice-jam floods: case study in Yukon Flats, Alaska
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 analysis that integrates satellite-derived gradients i
Authors
Steve M. Jepsen, Michelle Ann Walvoord, Clifford I. Voss, Jennifer R. Rover
Multimodel analysis of anisotropic diffusive tracer-gas transport in a deep arid unsaturated zone
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 sediments remain uncertain. In this study, we use a multi
Authors
Christopher T. Green, Michelle Ann Walvoord, Brian J. Andraski, Robert G. Striegl, David A. Stonestrom
Using dissolved organic matter age and composition to detect permafrost thaw in boreal watersheds of interior Alaska
Recent warming at high latitudes has accelerated permafrost thaw, which can modify soil carbon dynamics and watershed hydrology. The flux and composition of dissolved organic matter (DOM) from soils to rivers are sensitive to permafrost configuration and its impact on subsurface hydrology and groundwater discharge. Here, we evaluate the utility of DOM composition and age as a tool for detecting pe
Authors
Jonathan A. O'Donnell, George R. Aiken, Michelle Ann Walvoord, Peter A. Raymond, Kenna D. Butler, Mark M. Dornblaser, Katherine Heckman
Sensitivity of airborne geophysical data to sublacustrine and near-surface permafrost thaw
A coupled hydrogeophysical forward and inverse modeling approach is developed to illustrate the ability of frequency-domain airborne electromagnetic (AEM) data to characterize subsurface physical properties associated with sublacustrine permafrost thaw during lake-talik formation. Numerical modeling scenarios are evaluated that consider non-isothermal hydrologic responses to variable forcing from
Authors
Burke J. Minsley, Tristan Wellman, Michelle Ann Walvoord, Andre Revil
Spatial variability and landscape controls of near-surface permafrost within the Alaskan Yukon River Basin
The distribution of permafrost is important to understand because of permafrost's influence on high-latitude ecosystem structure and functions. Moreover, near-surface (defined here as within 1 m of the Earth's surface) permafrost is particularly susceptible to a warming climate and is generally poorly mapped at regional scales. Subsequently, our objectives were to (1) develop the first-known binar
Authors
Neal J. Pastick, M. Torre Jorgenson, Bruce K. Wylie, Joshua R. Rose, Matthew Rigge, Michelle Ann Walvoord
Field-scale sulfur hexafluoride tracer experiment to understand long distance gas transport in the deep unsaturated zone
A gas-tracer test in a deep arid unsaturated zone demonstrates that standard estimates of effective diffusivity from sediment properties allow a reasonable first-cut assessment of gas contaminant transport. Apparent anomalies in historic transport behavior at this and other waste disposal sites may result from factors other than nonreactive gas transport properties.
A natural gradient SF6 tracer e
Authors
Michelle Ann Walvoord, Brian J. Andraski, Christopher T. Green, David A. Stonestrom, Robert G. Striegl
New permafrost is forming around shrinking Arctic lakes, but will it last?
Widespread lake shrinkage in cold regions has been linked to climate warming and permafrost thaw. Permafrost aggradation, however, has been observed within the margins of recently receded lakes, in seeming contradiction of climate warming. Here permafrost aggradation dynamics are examined at Twelvemile Lake, a retreating lake in interior Alaska. Observations reveal patches of recently formed perma
Authors
Martin A. Briggs, Michelle Ann Walvoord, Jeffrey M. McKenzie, Clifford I. Voss, Frederick D. Day-Lewis, John W. Lane
Non-USGS Publications**
Walvoord, M.A., 2002, A Unifying Conceptual Model to Describe Water, Vapor, and Solute Transport in Deep Arid Vadose Zones, Ph.D. thesis, New Mexico Institute of Mining and Technology, Socorro, NM, 297 p.
Hartsough P.C., S.W. Tyler, J. Sterling, M.A. Walvoord, 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.
Walvoord, M., P. Pegram, F. Phillips, M. Person, T. Kieft, J. Fredrickson, J. McKinley, J. Swenson, 1999, Groundwater flow and geochemistry in the southeastern San Juan Basin: Implications for microbial transport and activity, Water Resources Research, 35, 1409 – 1425.
Walvoord, M., 1998, Characterization of Groundwater Flow in the Southeastern San Juan Basin: Implications for Microbial Origins in the Deep Subsurface Near Cerro Negro, New Mexico, MS thesis, New Mexico Tech, Socorro, NM, 142 p.
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
Science and Products
Filter Total Items: 66
Multi-scale geophysical mapping of deep permafrost change after disturbance in interior Alaska, USA
Disturbance related to fire or hydrologic processes can cause degradation of deep (greater than 1 m) permafrost. These changes in deep permafrost have the potential to impact landscapes and infrastructure, alter the routing and distribution of surface water or groundwater, and may contribute to the flux of carbon to terrestrial and aquatic ecosystems. However, characterization of deep permafrost o
Authors
Burke J. Minsley, Benjamin R. Bloss, Brian A. Ebel, David Matthew Rey, Michelle A. Walvoord, Dana R.N. Brown, Ronald Daanen, Abraham M. Emond, M. Andy Kass, Neal J. Pastick, Bruce Wylie
Unsaturated zone CO2, CH4, and δ13C-CO2 at an arid region low-level radioactive waste disposal site
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 and CH4, two additional important species in the unsat
Authors
Christopher H. Conaway, Michelle Ann Walvoord, Randall B. Thomas, Christopher Green, R.J. Baker, James J. Thordsen, David A. Stonestrom, Brian J. Andraski
Surface geophysical methods for characterising frozen ground in transitional permafrost landscapes
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 lacks the resolution to characterise finer-scale proces
Authors
Martin A. Briggs, Seth Campbell, Jay Nolan, Michelle Ann Walvoord, Dimitrios Ntarlagiannis, Frederick D. Day-Lewis, John W. Lane
Hydrologic impacts of thawing permafrost—A review
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, and the partitioning of water stored above and belo
Authors
Michelle Ann Walvoord, Barret L. Kurylyk
Implications of projected climate change for groundwater recharge in the western United States
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 the development of water policy. An analysis of the p
Authors
Thomas Meixner, Andrew H. Manning, David A. Stonestrom, Diana M. Allen, Hoori Ajami, Kyle W. Blasch, Andrea E. Brookfield, Christopher L. Castro, Jordan F. Clark, David Gochis, Alan L. Flint, Kirstin L. Neff, Rewati Niraula, Matthew Rodell, Bridget R. Scanlon, Kamini Singha, Michelle Ann Walvoord
Effect of permafrost thaw on the dynamics of lakes recharged by ice-jam floods: case study in Yukon Flats, Alaska
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 analysis that integrates satellite-derived gradients i
Authors
Steve M. Jepsen, Michelle Ann Walvoord, Clifford I. Voss, Jennifer R. Rover
Multimodel analysis of anisotropic diffusive tracer-gas transport in a deep arid unsaturated zone
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 sediments remain uncertain. In this study, we use a multi
Authors
Christopher T. Green, Michelle Ann Walvoord, Brian J. Andraski, Robert G. Striegl, David A. Stonestrom
Using dissolved organic matter age and composition to detect permafrost thaw in boreal watersheds of interior Alaska
Recent warming at high latitudes has accelerated permafrost thaw, which can modify soil carbon dynamics and watershed hydrology. The flux and composition of dissolved organic matter (DOM) from soils to rivers are sensitive to permafrost configuration and its impact on subsurface hydrology and groundwater discharge. Here, we evaluate the utility of DOM composition and age as a tool for detecting pe
Authors
Jonathan A. O'Donnell, George R. Aiken, Michelle Ann Walvoord, Peter A. Raymond, Kenna D. Butler, Mark M. Dornblaser, Katherine Heckman
Sensitivity of airborne geophysical data to sublacustrine and near-surface permafrost thaw
A coupled hydrogeophysical forward and inverse modeling approach is developed to illustrate the ability of frequency-domain airborne electromagnetic (AEM) data to characterize subsurface physical properties associated with sublacustrine permafrost thaw during lake-talik formation. Numerical modeling scenarios are evaluated that consider non-isothermal hydrologic responses to variable forcing from
Authors
Burke J. Minsley, Tristan Wellman, Michelle Ann Walvoord, Andre Revil
Spatial variability and landscape controls of near-surface permafrost within the Alaskan Yukon River Basin
The distribution of permafrost is important to understand because of permafrost's influence on high-latitude ecosystem structure and functions. Moreover, near-surface (defined here as within 1 m of the Earth's surface) permafrost is particularly susceptible to a warming climate and is generally poorly mapped at regional scales. Subsequently, our objectives were to (1) develop the first-known binar
Authors
Neal J. Pastick, M. Torre Jorgenson, Bruce K. Wylie, Joshua R. Rose, Matthew Rigge, Michelle Ann Walvoord
Field-scale sulfur hexafluoride tracer experiment to understand long distance gas transport in the deep unsaturated zone
A gas-tracer test in a deep arid unsaturated zone demonstrates that standard estimates of effective diffusivity from sediment properties allow a reasonable first-cut assessment of gas contaminant transport. Apparent anomalies in historic transport behavior at this and other waste disposal sites may result from factors other than nonreactive gas transport properties.
A natural gradient SF6 tracer e
Authors
Michelle Ann Walvoord, Brian J. Andraski, Christopher T. Green, David A. Stonestrom, Robert G. Striegl
New permafrost is forming around shrinking Arctic lakes, but will it last?
Widespread lake shrinkage in cold regions has been linked to climate warming and permafrost thaw. Permafrost aggradation, however, has been observed within the margins of recently receded lakes, in seeming contradiction of climate warming. Here permafrost aggradation dynamics are examined at Twelvemile Lake, a retreating lake in interior Alaska. Observations reveal patches of recently formed perma
Authors
Martin A. Briggs, Michelle Ann Walvoord, Jeffrey M. McKenzie, Clifford I. Voss, Frederick D. Day-Lewis, John W. Lane
Non-USGS Publications**
Walvoord, M.A., 2002, A Unifying Conceptual Model to Describe Water, Vapor, and Solute Transport in Deep Arid Vadose Zones, Ph.D. thesis, New Mexico Institute of Mining and Technology, Socorro, NM, 297 p.
Hartsough P.C., S.W. Tyler, J. Sterling, M.A. Walvoord, 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.
Walvoord, M., P. Pegram, F. Phillips, M. Person, T. Kieft, J. Fredrickson, J. McKinley, J. Swenson, 1999, Groundwater flow and geochemistry in the southeastern San Juan Basin: Implications for microbial transport and activity, Water Resources Research, 35, 1409 – 1425.
Walvoord, M., 1998, Characterization of Groundwater Flow in the Southeastern San Juan Basin: Implications for Microbial Origins in the Deep Subsurface Near Cerro Negro, New Mexico, MS thesis, New Mexico Tech, Socorro, NM, 142 p.
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
*Disclaimer: Listing outside positions with professional scientific organizations on this Staff Profile are for informational purposes only and do not constitute an endorsement of those professional scientific organizations or their activities by the USGS, Department of the Interior, or U.S. Government