Tristan MacLean, Author at PermafrostNet

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-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.

By Tristan MacLean, 7 moisjuillet 10, 2024 ago

Field work training at Foret Montmorency

The network recently hosted a fieldwork training event at the Fort Montmorency research station of Université Laval.

The first day was packed with exciting and valuable sessions, from navigation training by Pia Blake to hands-on installation and location of ground temperature sensors by Galina Jonat et Olivia Meier-Legault, followed by discussions about field safety and situations led by Tristan MacLean.

The navigation session started off with everyone creating 3D models of their topographic maps, followed by outdoor location of waypoints, on and off the trails, using maps, compass and GPS.

In the afternoon, after an introduction to temperature sensors and their use in permafrost terrain by Galina and Olivia, the trainees were split into two groups, to test out their abilities at finding buried sensors based on location information and the use of a metal detector to find associated nails.

Day two was even more action packed, featuring drone flying, lectures on detecting ground ice and a competitive shelter building session followed by fire making practice with the ferro rods and some good old marshmallow toasting.

The morning featured a session on demystifying remotely piloted aircraft for field research with Frederic Brieger. Thankfully the rain held off and we were able to get out and get the drones up in the air.

The afternoon started off with a presentation on ERT and Spectral Induced Polarization by Hosein Fereydooni, before we headed out to see the flux tower and learn about eddy co-variance with Bruno Lecavalier. The group then took part in a competitive but very friendly time-limited challenge to construct a shelter in the wild with limited resources. The session was led, and each teams efforts carefully assessed by Frederic and Galina.

The day was completed with a tricky but satisfying fire-making session using a variety of survival tools and natural kindling.

By Tristan MacLean, 9 moismai 30, 2024 ago

POSTPONED Seminar – 29 May – Performance of Drilling Waste Sumps, Western Arctic Canada.

Rae Landriau will be presenting Performance of Drilling Waste Sumps, Western Arctic Canada.

Date: 29 May 2024
Time: 13:00-14:00 Eastern Time
Location: Zoom (details are posted in our Teams site).

Petroleum resource exploration and development has occurred in the Northwest Territories since the 1920s. Freezing-point depressants, mainly potassium chloride, were added to drilling fluids to facilitate drilling into permafrost. Disposal of these fluids was typically in large man-made pits (sumps). Sumps were excavated in permafrost, with the intention that frozen ground would contain the fluids indefinitely. Climatic warming in northwest Canada has raised the temperature of near-surface permafrost, increasing the potential for failure of sumps in the region. Using electro-magnetic surveys, ground conductivity on and off sumps can be collected and analyzed to detect the presence of these fluids and determine if they have migrated.

By Tristan MacLean, 11 moismars 26, 2024 ago

Seminar – 22 May – Precise Change Detection with Airborne Interferometric Synthetic Aperture Radar (InSAR) & Optical Photogrammetry Data and its application to Active Permafrost Regions.

Usman Iqbal Ahmed will be presenting Precise Change Detection with Airborne Interferometric Synthetic Aperture Radar (InSAR) & Optical Photogrammetry Data and its application to Active Permafrost Regions.

Date: 22 May 2024
Time: 13:00-14:00 Eastern Time
Location: Zoom (details are posted in our Teams site).

Permafrost thaw can cause several problems; the ground becomes unstable and can cause damage to infrastructure such as roads, buildings, and pipelines. It can also cause erosion and changes in the landscape, which can have ecological and social impacts and disruption of indigenous ways of life. Monitoring these changes is a key factor in reducing the impact of such disasters as well as timely reaction/adaptation to such changes. I am exploring the option of developing a change detection method using Airborne Synthetic Aperture Radar (SAR) Interferometry and Optical Photogrammetry data for precise change detection. I will present the results of our controlled experiment with simulated permafrost related changes to showcase the capability of our method in active permafrost thaw environments.

By Tristan MacLean, 11 moismars 25, 2024 ago

Seminar – 15 May – Ice-Wedge Volume, Distribution, and Development in the Barrens of the Hudson Bay Lowlands, Northern Manitoba.

Tabatha Rahman will be presenting Ice-Wedge Volume, Distribution, and Development in the Barrens of the Hudson Bay Lowlands, Northern Manitoba.

Date: 15 May 2024
Time: 13:00-14:00 Eastern Time
Location: Zoom (details are posted in our Teams site).

Extensive ice-wedge polygon networks are found in the ‘Barrens’ of northern Manitoba, a 50,000 km² zone of continuous permafrost tundra that emerged from the Tyrrell Sea less than 5,500 years ago. Tabatha will present empirical results of ice-wedge volume and tri-dimensional distribution, and will focus on the environmental conditions associated with the growth and degradation of ice wedges in this uplifted permafrost peatland. Knowledge of wedge-ice morphology and development is essential for the prediction and mitigation of risks associated with anticipated permafrost thaw in the Barrens.

By Tristan MacLean, 11 moismars 22, 2024 ago

Enregistrement et résumé AI de la Conférence sur la politique scientifique canadienne 2023

A Vision for Permafrost Knowledge in Canada: From Strategy to Action

Permafrost Pathways et le PermafrostNet CRSNG ont organisé des tables rondes distinctes lors de la conférence 2022 du Centre canadien de la politique scientifique (CCPS). Cela a conduit à une collaboration pour organiser un panel unique pour la conférence du CCPS 2023 afin de faire avancer les discussions commencées en 2022, intitulée : A Vision for Permafrost Knowledge in Canada: From Strategy to Actionqui s'est tenue le lundi 13 novembre. Les panélistes comprenaient : John Holdren (Arctic Initiative, Harvard Kennedy School), Marc D'Iorio (SMA Sciences, ECCC), Sara Brown (Association des communautés des Territoires du Nord-Ouest) et Stephan Gruber (PermafrostNet CRSNG), sous la présidence de Janet King, présidente du conseil d'administration. Janet King moderating.

To enable more in-depth discussions and strategizing, Jennifer Spence (Carleton University; Arctic Initiative, Harvard Kennedy School) and Janet King organized a workshop that followed the panel titled: Advancing Canada’s role as a leader in permafrost knowledge and policy. The workshop featured representatives of ITK, NWT Association of Communities, ECCC, the federal government’s Working Group on permafrost, Polar Knowledge Canada, the Geological Survey of Canada, the NWT Geological Survey, the Canadian Permafrost Association, NSERC PermafrostNet, Permafrost Pathways, ArcticNet, Woodwell Climate Research Centre, and the Cascade Institute.

Vous pouvez maintenant lire tous les détails du panel, obtenir un résumé AI de la discussion et écouter l'enregistrement audio du symposium sur le site web CSPC webpage for the session.

By Tristan MacLean, 11 moismars 21, 2024 ago

Seminar – 8 May – The Effects of Environmental Controls on Epigenetic Ice-Wedge Cracking.

Gabriel Karam will be presenting The Effects of Environmental Controls on Epigenetic Ice-Wedge Cracking.

Date: 8 May 2024
Time: 13:00-14:00 Eastern Time
Location: Zoom (details are posted in our Teams site).

Ice-wedge polygons are a widespread periglacial feature in the continuous permafrost regions. To better understand the mechanical aspects of their formation, the extended finite-element method was employed to simulate the cracking process. Four case studies will be presented, which evaluate the effects different environmental controls and explore the growth of wedges over multiple years.

By Tristan MacLean, 11 moismars 21, 2024 ago

Seminar – 1 May – Advancing Arctic coastal erosion measurement and monitoring through UAV-SfM and object-based image analysis.

Andrew Clark will be presenting Advancing Arctic coastal erosion measurement and monitoring through UAV-SfM and object-based image analysis.

Date: 1 May 2024
Time: 13:00-14:00 Eastern Time
Location: Zoom (details are posted in our Teams site).

Arctic coasts are vast and exhibit some of the highest rates of erosion in the World due to the presence of permafrost. Rates of erosion are expected to increase with warming air and water temperatures, reductions in Arctic sea ice extent and duration, sea level rise, and increased storm severity and frequency. This presentation will describe the use of emerging technologies (UAV-SfM and OBIA) to further our understanding of Arctic coastal processes, specifically, volumetric erosion, and broad scale delineation of multiple shoreline proxies for monitoring and quantification of erosion.

By Tristan MacLean, 11 moismars 20, 2024 ago

Le secret des tourbières par Radio-Canada

Un reportage à Découverte de Radio-Canada avec Oliver Sonnentag.

Face au réchauffement de la planète, les scientifiques tirent la sonnette d’alarme : il est temps de prendre conscience des pouvoirs de la tourbe. D’un labo de biopharmacie en Irlande à la plus grande tourbière d’Europe, en passant par la cabane d’un piégeur et la plus vaste expérience sur le changement climatique, Le secret des tourbières nous dévoile la beauté et les merveilles des tourbières. Avec Oliver Sonnentag, à la minute 22:45.

Regarder ici: https://ici.radio-canada.ca/tele/decouverte/site/episodes/865999/tourbieres-foret-amazonie-planete

By Tristan MacLean, 11 moismars 20, 2024 ago

Ottawa-Carleton Northern Research Symposium

The OCSNRS is an annual student academic conference focusing on Subarctic, Arctic and Antarctic research from natural & physical sciences, social sciences, humanities and applied sciences.

This year the University of Ottawa hosted the meeting which featured a number of permafrost presentations from the network:

Galina Jonat – A proposed Framework for Improved Simulations of Permafrost Change.
Frederic Brieger – Permafrost Terrain Disturbance Mapping and Susceptibility Modeling in the Na-Cho Nyäk Ge (Stewart River) Watershed, Yukon.
Rae Landriau – Performance of Drilling Waste Sumps – Mackenzie Delta NT.
Pia Blake – Effects of Snow and Surface Material on Surface Offset of Intermediate Slopes.