publication

Investigating the controls of ice-wedge initiation and growth using XFEM

A study of how climate, soil type and water saturation affect ice-wedge cracks

A new study by Gabriel Karam et al asks, how do climate and soil control the ice-wedge formation process?

Answering these questions can further our understanding of wedge-ice volume and distribution.

Ice wedge cracking simulation gif

Ice-wedges are periglacial landforms that develop as a result of thermal contraction-cracking in continuous permafrost regions, which appear as polygonal networks on the ground surface. Given their complex thermo- mechanical loading history, very few related numerical models have so far been developed. This study developed a new climate-driven model to show the fractures in soil that develop from thermal contraction in winter. The range of model results indicate how climate, soil type and water saturation of the soil affect the spacing, depth, and width of ice-wedge cracks. Estimating ice-wedge depth can help us make informed volume calculations which are otherwise difficult to measure in the field.

Karam, G., Pouragha, M. and Gruber, S. (2024). Investigating the controls of ice-wedge initiation and growth using XFEM, Computers and Geotechnics, Volume 173, DOI: 10.1016/j.compgeo.2024.106549

A typical simulation result showing multiple cracks.
A typical simulation result showing multiple cracks.

By Tristan MacLean, ago

A prototype field-to-publication data system for a multi-variable permafrost observation network.

A prototype field-to-publication data system for a multi-variable permafrost observation network.
Blog post by Nick Brown, NSERC PermafrostNet Data Scientist

Analysis and prediction of permafrost change are hampered by lack of observational data. In collaboration with Stephan Gruber, Peter Pulsifer, and Amos Hayes, we developed a permafrost data management system to support permafrost observation networks that involve many different kinds of permafrost data.

We identify five broad challenges for permafrost data management and publication: (1) existing data management strategies do not scale well, (2) data users have different skills and needs, (3) permafrost data are varied, (4) resources for permafrost data management are limited, and (5) existing permafrost data sources are difficult to integrate. Our prototype system supports a permafrost data workflow from observation to the distribution of interoperable data. The system simplifies data publication and management, although we identify and discuss several hurdles in adapting the CF conventions and ERDDAP for permafrost data. Our learning can inform organizations who collect, manage, or distribute permafrost data or those who manage large observation networks.

In summary:

  • Five broad challenges limit permafrost data management and publication.
  • We frame these challenges as requirements, and identify similarities with the FAIR principles.
  • We developed a prototype a permafrost data system to support field-to-publication workflows.
  • In this project, we use an “adopt and adapt” approach for standards and software.
  • Our data system supports more FAIR permafrost data.

Nicholas Brown, Stephan Gruber, Peter Pulsifer, Amos Hayes, A prototype field-to-publication data system for a multi-variable permafrost observation network, Environmental Modelling & Software, Volume 175, 2024, 106006, ISSN 1364-8152, doi:10.1016/j.envsoft.2024.106006

This research was enabled in part by support provided by Compute Ontario and the Digital Research Alliance of Canada.

By nick brown, ago
The study area showing the Hudson Bay Railway extending from Churchill to The Pas, Manitoba.

A study of thermal modeling parameters and their impact on modelled permafrost responses to climate warming

A study of thermal modeling parameters and their impact on modelled permafrost responses to climate warming

A study by Khatereh Roghangar and Jocelyn Hayley has assessed the effects of thermal modeling parameters on permafrost ground response to climate warming. They analyzed how variations in depth, water content, and soil type affect predictions of future active layer depths and settlement under various climate scenarios using the soil characteristics along Hudson Bay Railway corridor.

The results indicate that, for fine-grained soils, the depth of the model is a more significant parameter than for coarse-grained soils. The water content of all soil types is a critical factor in determining the time at which permafrost thaws and the depth at which the active layer is located, as higher water content leads to larger active layer changes and more settlement in most cases. These findings have important implications for infrastructure and land use management in the Arctic region.

Roghangar, K. and Hayley, J.L. (2024). A study of thermal modeling parameters and their impact on modelled permafrost responses to climate warming. Cold Regions Science and Technology, 221, 104155, DOI: 10.1016/j.coldregions.2024.104155.

The study area showing the Hudson Bay Railway extending from Churchill to The Pas, Manitoba.
The study area showing the Hudson Bay Railway extending from Churchill to The Pas, Manitoba.

By Tristan MacLean, ago
Core in the core boat on the MSCL track.

Non-destructive multi-sensor core logging allows for rapid imaging and estimation of frozen bulk density and volumetric ice content in permafrost cores.

Non-destructive multi-sensor core logging allows for rapid imaging and estimation of frozen bulk density and volumetric ice content in permafrost cores

Exciting research in the Permafrost ArChives Science Laboratory (PACS Lab) at the University of Alberta has demonstrated a novel application of multi-sensor core logging for analyzing permafrost cores.

Measurements of core physical properties are typically destructive and time intensive.

Non-destructive multi-sensor core logging (MSCL) can efficiently analyze permafrost samples and provide high-resolution insights without these problems. The  new technique allows rapid imaging, measurement of bulk density and estimation of ice content in permafrost cores. The team were able to visualize cryostructures and estimate frozen bulk density, magnetic susceptibility, and volumetric ice content.

The new technique is described in the paper published in The Cryosphere by Duane Froese’s lab: Pumple, J., Monteath, A., Harvey, J., Roustaei, M., Alvarez, A., Buchanan, C., and Froese, D.: Non-destructive multi-sensor core logging allows for rapid imaging and estimation of frozen bulk density and volumetric ice content in permafrost cores, The Cryosphere, 18, 489–503, https://doi.org/10.5194/tc-18-489-2024, 2024.

Core in the core boat on the MSCL track.
Core in the core boat on the MSCL track.

By Tristan MacLean, ago
Yukon Territory and western Northwest Territories, including Mackenzie Mountains and adjacent Mackenzie River Valley, with locations of all weather stations.

Performance of climate projections for Yukon and adjacent Northwest Territories.

Performance of climate projections for Yukon and adjacent Northwest Territories.

The design of infrastructure on permafrost must account for the impacts of a changing climate on ground stability. While guidelines like CSA PLUS 4011:19 provide a framework, choosing appropriate climate scenarios remains a challenge.

The study by Astrid Schetselaar, Trevor Anderson and Chris Burn reveals that observed warming in the Yukon and Northwest Territories (1991-2020) aligns with more extreme climate projections made in 2003 for the Mackenzie Gas Project.

Key takeaways for developers:

  • Consider adopting more aggressive climate change scenarios when designing permafrost foundations, as these projections have been more accurate.
  • Near-surface permafrost in southern parts of the region may become unsustainable. Thorough site investigations for thaw-stable soils are crucial.
  • Rising winter temperatures imply that the operational efficacy of thermosyphons, used to chill foundations, may be impeded.  At sites where preservation of frozen ground is essential for infrastructure integrity, the number of thermosyphons required may need to increase.

Schetselaar, A.B., Andersen, T.S., and Burn, C.R. 2023. Performance of climate projections for Yukon and adjacent Northwest Territories, 1991-2020. Arctic, 76(3). doi: 10.14430/arctic77263

Yukon Territory and western Northwest Territories, including Mackenzie Mountains and adjacent Mackenzie River Valley, with locations of all weather stations.
Yukon Territory and western Northwest Territories, including Mackenzie Mountains and adjacent Mackenzie River Valley, with locations of all weather stations.

By Tristan MacLean, ago
Comparison of mountain areas with permafrost in western Canada (coloured) and European areas (grey) for mean annual air temperature and total annual precipitation at a resolution of 30 km x 30 km.

Transferring Cryosphere Knowledge between Mountains Globally: A Case Study of Western Canadian Mountains, the European Alps and the Scandes

Transferring Cryosphere Knowledge between Mountains Globally: A Case Study of Western Canadian Mountains, the European Alps and the Scandes

Most mountain permafrost research has been focussed on the small area of the European alps. This leads to the question, can you transfer cryosphere knowledge from the Scandes and Alps to Canada?

Emilie Stewart-Jones, has now developed a method for comparing regional climates at a coarse scale to highlight similarities and differences. Her paper “Transferring Cryosphere Knowledge between Mountains Globally: A Case Study of Western Canadian Mountains, the European Alps and the Scandes” published in the Journal of Alpine Research in November can now answer the question of whether we can transfer our knowledge of permafrost in one region to another.

Comparison of mountain areas with permafrost in western Canada (coloured) and European areas (grey) for mean annual air temperature and total annual precipitation at a resolution of 30 km x 30 km.
Comparison of mountain areas with permafrost in western Canada (coloured) and European areas (grey) for mean annual air temperature and total annual precipitation at a resolution of 30 km x 30 km.

By Tristan MacLean, ago
Coverage of the ArcticDEM in the Arctic with permafrost extent.

Identifying active retrogressive thaw slumps from ArcticDEM

 Identifying active retrogressive thaw slumps from ArcticDEM

The extent of permafrost thaw in the pan-Arctic remains unknown, but remote sensing, deep learning and crowdsourcing are helping to map permafrost degradation in the landscape.

The recent study by Huang et al study provides data and serves to develop a global inventory and better understand permafrost thaw in the pan-Arctic using very high resolution remote sensing. This approach could lead to a global inventory of retrogressive thaw slumps.

Lingcao Huang, Michael J. Willis, Guiye Li, Trevor C. Lantz, Kevin Schaefer, Elizabeth Wig, Guofeng Cao, Kristy F. Tiampo, Identifying active retrogressive thaw slumps from ArcticDEM, ISPRS Journal of Photogrammetry and Remote Sensing, Volume 205, 2023, Pages 301-316, ISSN 0924-2716.

Coverage of the ArcticDEM in the Arctic with permafrost extent.
Coverage of the ArcticDEM in the Arctic with permafrost extent.

By Tristan MacLean, ago
Global map summarizing locations of field sites where electrical resistivity tomography (ERT) has been used to study permafrost (2000–22) based on the literature search.

Best practices for using electrical resistivity tomography to investigate permafrost.

Best practices for using electrical resistivity tomography to investigate permafrost

A recent study by Teddi Herring suggests ways to improve how Electrical Resistivity Tomography (ERT) is used for permafrost and highlights recent advances in this approach. ERT is a technique that is incredibly useful for studying permafrost, enabling us to see how deep the permafrost layer is and identify areas with ice content.

There has been a 10-fold increase in publications of studies using ERT to analysis permafrost in the last 20 years, and though challenges remain, and there’s no single “best way” to do it yet, the study makes recommendations for conducting ERT surveys to maximize the utility of existing and future data.

Herring T,  Lewkowicz AG,  Hauck C, et al.  Best practices for using electrical resistivity tomography to investigate permafrost. Permafrost and Periglac Process.  2023; 34(4): 494-512. doi:10.1002/ppp.2207

Global map summarizing locations of field sites where electrical resistivity tomography (ERT) has been used to study permafrost (2000–22) based on the literature search.
Global map summarizing locations of field sites where electrical resistivity tomography (ERT) has been used to study permafrost (2000–22) based on the literature search.

By Tristan MacLean, ago
Project organization, roles and institutional involvement by location.

The Northwest Territories Thermokarst Mapping Collective: a northern-driven mapping collaborative toward understanding the effects of permafrost thaw

The Northwest Territories Thermokarst Mapping Collective: a northern-driven mapping collaborative toward understanding the effects of permafrost thaw.

A paper by the Thermokarst Mapping Collective (TMC), a research collaborative to systematically inventory indicators of permafrost thaw sensitivity by mapping and aerial assessments across the Northwest Territories (NT), Canada, has documented the first comprehensive inventory of thermokarst and thaw-sensitive terrain indicators for a 2 million km2 region of northwestern Canada.

Kokelj, S.V. et al. The Northwest Territories Thermokarst Mapping Collective: a northern-driven mapping collaborative toward understanding the effects of permafrost thaw. Arctic Science. E First. DOI: 10.1139/as-2023-0009.

Project organization, roles and institutional involvement by location.
Project organization, roles and institutional involvement by location.

By Tristan MacLean, ago

New publication: Ground subsidence and heave over permafrost.

Ground subsidence and heave over permafrost: hourly time series reveal interannual, seasonal and shorter-term movement caused by freezing, thawing and water movement.

Heave and subsidence of the ground surface can offer insight into processes of heat and mass transfer in freezing and thawing soils. Additionally, subsidence is an important metric for monitoring and understanding the transformation of permafrost landscapes under climate change. Corresponding ground observations, however, are sparse and episodic. A simple tilt-arm apparatus with logging inclinometer has been developed to measure heave and subsidence of the ground surface with hourly resolution and millimeter accuracy. This contribution reports data from the first two winters and the first full summer, measured at three sites with contrasting organic and frost-susceptible soils in warm permafrost. The patterns of surface movement differ significantly between sites and from a prediction based on the Stefan equation and observed ground temperature. The data are rich in features of heave and subsidence that are several days to several weeks long and that may help elucidate processes in the ground. For example, late-winter heave followed by thawing and subsidence, as reported in earlier literature and hypothesized to be caused by infiltration and refreezing of water into permeable frozen ground, has been detected. An early-winter peak in heave, followed by brief subsidence, is discernible in a previous publication but so far has not been interpreted. An effect of precipitation on changes in surface elevation can be inferred with confidence. These results highlight the potential of ground-based observation of subsidence and heave as an enabler of progress in process understanding, modeling and interpretation of remotely sensed data.

Gruber, S.: Ground subsidence and heave over permafrost: hourly time series reveal interannual, seasonal and shorter-term movement caused by freezing, thawing and water movement. The Cryosphere, 14, 1437–1447, https://doi.org/10.5194/tc-14-1437-2020, 2020.

By Tristan MacLean, ago