Michelle A. Walvoord

United States Geological Survey

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Clifford I. Voss

United States Geological Survey

B. J. Minsley

United States Geological Survey

Christopher Spence

Environment and Climate Change Canada

Bridget R. Scanlon

The University of Texas at Austin

Christophe Ancey

École Polytechnique Fédérale de Lausanne

Anton Kruger

Charles River Laboratories (Netherlands)

Dubravka Pokrajac

University of Aberdeen

Amin Elshorbagy

University of Saskatchewan

Nicholas Howden

University of Bristol

Markus Hrachowitz

Delft University of Technology

Cooperative Institutions

John Wiley & Sons (United States)

190

United States Geological Survey

126

Charles River Laboratories (Netherlands)

122

Pacific Island Ecosystems Research Center

University of Colorado Boulder

University of California, Berkeley

University of Alaska Fairbanks

University of Arizona

Denver Federal Center

Stanford University

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Wildfire‐Initiated Talik Development Exceeds Current Thaw Projections: Observations and Models From Alaska's Continuous Permafrost Zone

Geophysical Research Letters (2020)

David M. Rey Michelle A. Walvoord B. J. Minsley Brian A. Ebel Clifford I. Voss

Abstract As the Arctic warms and wildfire occurrence increases, talik formation in permafrost regions is projected to expand and affect the cycling of water and carbon. Yet, few unified field and modeling studies have examined this process in detail, particularly in areas of continuous permafrost. We address this gap by presenting multimethod, multiseasonal geophysical measurements of permafrost and liquid‐water content that reveal substantial talik development in response to recent wildfire in continuous permafrost of boreal Alaska. Results from observation‐based cryohydrogeologic model simulations suggest that predisturbance subsurface conditions are key factors influencing thaw response to fire disturbance and air temperature warming. Our high‐resolution integrated study illustrates enhanced vulnerability of boreal continuous permafrost, with observed talik formation that exceeds coarse‐scale model projections by ~100 years even under the most extreme future emissions scenario. Results raise important scaling questions for representing extreme permafrost thaw phenomena of growing widespread importance in large‐scale predictive models.

Thermokarst

10.1029/2020gl087565

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Citations (39)

Evaluating permafrost thaw vulnerabilities and hydrologic impacts in boreal Alaska (USA) watersheds using field data and cryohydrogeologic modeling

AGU Fall Meeting Abstracts (2017)

Michelle A. Walvoord Clifford I. Voss Brian A. Ebel B. J. Minsley

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Shrinking Arctic Lakes are Forming New Local Permafrost, but for How Long?

AGUFM (2013)

Martin A. Briggs Michelle A. Walvoord Jeffrey M. McKenzie Clifford I. Voss F. D. Day‐Lewis

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Measurement and Modeling of Perennial Thaw Zone Development in Boreal Alaska

AGU Fall Meeting Abstracts (2019)

D. Rey Michelle A. Walvoord B. J. Minsley Brian A. Ebel Clifford I. Voss

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Issue Information

Water Resources Research (2020)

Martyn Clark Kumud Acharya Newsha Ajami Christophe Ancey Stacey Archfi

No abstract is available for this article.

10.1002/wrcr.24003

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Understanding response times and groundwater flow dynamics of thaw zone (talik) evolution below lakes in the Yukon Flats, Alaska, USA

AGUFM (2013)

T. P. Wellman B. J. Minsley Clifford I. Voss Michelle A. Walvoord

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Effects of environmental change on groundwater recharge in the desert southwest

Water science and application (2004)

Fred M. Phillips Michelle A. Walvoord Eric E. Small

This chapter contains sections titled: Introduction Mechanisms for Change in Recharge Effects of Changes in Recharge Rate on Groundwater Systems Paleoenvironmental Evidence for Changes in Recharge in the Western United States During the Late Quaternary Response of Groundwater Systems to Variations in Late Quaternary Environmental Conditions Prediction of Response to Current and Future Environmental Changes

Environmental change

Depression-focused recharge

10.1029/009wsa15

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Sensitivity of airborne geophysical data to sublacustrine and near-surface permafrost thaw

The cryosphere (2015)

B. J. Minsley T. P. Wellman Michelle A. Walvoord A. Revil

Abstract. 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 different lake depths and for different hydrologic gradients. A novel physical property relationship connects the dynamic distribution of electrical resistivity to ice saturation and temperature outputs from the SUTRA groundwater simulator with freeze–thaw physics. The influence of lithology on electrical resistivity is controlled by a surface conduction term in the physical property relationship. Resistivity models, which reflect changes in subsurface conditions, are used as inputs to simulate AEM data in order to explore the sensitivity of geophysical observations to permafrost thaw. Simulations of sublacustrine talik formation over a 1000-year period are modeled after conditions found in the Yukon Flats, Alaska. Synthetic AEM data are analyzed with a Bayesian Markov chain Monte Carlo algorithm that quantifies geophysical parameter uncertainty and resolution. Major lithological and permafrost features are well resolved by AEM data in the examples considered. The subtle geometry of partial ice saturation beneath lakes during talik formation cannot be resolved using AEM data, but the gross characteristics of sub-lake resistivity models reflect bulk changes in ice content and can identify the presence of a talik. A final synthetic example compares AEM and ground-based electromagnetic responses for their ability to resolve shallow permafrost and thaw features in the upper 1–2 m below ground outside the lake margin.

Saturation (graph theory)

Electrical Resistivity Tomography

10.5194/tc-9-781-2015

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USGS permafrost research determines the risks of permafrost thaw to biologic and hydrologic resources

Fact sheet (2021)

Mark P. Waldrop Lesleigh Anderson M. Dornblaser Li Erikson Ann E. Gibbs

First posted January 19, 2021 For additional information, contact: Alaska Regional Director4210 University DriveAnchorage, AK 99508907–786–7091 The U.S. Geological Survey (USGS), in collaboration with university, Federal, Tribal, and independent partners, conducts fundamental research on the distribution, vulnerability, and importance of permafrost in arctic and boreal ecosystems. Scientists, land managers, and policy makers use USGS data to help make decisions for development, wildlife habitat, and other needs. Native villages and cities can forecast landscape change and where soils are vulnerable to thaw with more certainty. The scientific community can use USGS data to develop scenarios of future permafrost change.

Geological survey

10.3133/fs20203058

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Citations (1)

CO₂ dynamics in the Amargosa Desert: Fluxes and isotopic speciation in a deep unsaturated zone

Water Resources Research (2005)

Michelle A. Walvoord Robert G. Striegl David E. Prudic David A. Stonestrom

Natural unsaturated‐zone gas profiles at the U.S. Geological Survey's Amargosa Desert Research Site, near Beatty, Nevada, reveal the presence of two physically and isotopically distinct CO 2 sources, one shallow and one deep. The shallow source derives from seasonally variable autotrophic and heterotrophic respiration in the root zone. Scanning electron micrograph results indicate that at least part of the deep CO 2 source is associated with calcite precipitation at the 110‐m‐deep water table. We use a geochemical gas‐diffusion model to explore processes of CO 2 production and behavior in the unsaturated zone. The individual isotopic species 12 CO 2 , 13 CO 2 , and 14 CO 2 are treated as separate chemical components that diffuse and react independently. Steady state model solutions, constrained by the measured δ 13 C (in CO 2 ), and δ 14 C (in CO 2 ) profiles, indicate that the shallow CO 2 source from root and microbial respiration composes ∼97% of the annual average total CO 2 production at this arid site. Despite the small contribution from deep CO 2 production amounting to ∼0.1 mol m −2 yr −1 , upward diffusion from depth strongly influences the distribution of CO 2 and carbon isotopes in the deep unsaturated zone. In addition to diffusion from deep CO 2 production, 14 C exchange with a sorbed CO 2 phase is indicated by the modeled δ 14 C profiles, confirming previous work. The new model of carbon‐isotopic profiles provides a quantitative approach for evaluating fluxes of carbon under natural conditions in deep unsaturated zones.

Carbon fibers

10.1029/2004wr003599

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Citations (60)