Tristan MacLean

Seminar – 29 January – Understanding Frost Jacking Effects on Transportation Infrastructure in Permafrost Regions.

Natalie Arpin will be presenting Understanding Frost Jacking Effects on Transportation Infrastructure in Permafrost Regions: Insights from the Hudson Bay Railway.

Date: 29 January 2025
Time: 13:00-14:00 Eastern Time
Location: Zoom (details are posted in our Teams site).

The Hudson Bay Railway plays a crucial role in Canada by providing an all-season, land-based pathway to transport goods to Northern communities, but the diverse ground conditions, ranging from isolated to continuous permafrost, create significant obstacles in maintaining its operation. The presentation will discuss current efforts to improve understanding of how ground conditions affect railway bridges, with a specific focus on frost jacking.

By Tristan MacLean, ago

Seminar – 18 December – Measuring Active Layer Dynamics with InSAR.

Allison Plourde will be presenting Measuring Active Layer Dynamics with InSAR.

Date: 18 December 2024
Time: 13:00-14:00 Eastern Time
Location: Zoom (details are posted in our Teams site).

InSAR (Interferometric Synthetic Aperture Radar) is a well-established method for measuring small-scale surface deformations across vast regions. However, the influence of snow cover on InSAR phase limits the comprehensive tracking of seasonal dynamics in permafrost terrain. This study focuses on low-land permafrost near Inuvik, Northwest Territories, aiming to enhance understanding of permafrost active layer dynamics, particularly in winter. To tackle this, a multifaceted approach combining C-band and X-band InSAR measurements with in-situ data has been developed. Instrumentation at research sites includes inclinometers for vertical surface deformation, ultrasonic range finders for snow depth, and corner reflectors as InSAR references. This comprehensive approach aims to contribute valuable insights to the scientific understanding of permafrost monitoring techniques and addresses the impact of snow cover on InSAR measurements in permafrost terrain.

By Tristan MacLean, ago

Seminar – 4 December – A framework for evaluating thaw settlement.

Zakieh Mohammadi will be presenting A framework for evaluating thaw settlement.

Date: 4 December 2024
Time: 13:00-14:00 Eastern Time
Location: Zoom (details are posted in our Teams site).

Thaw settlement is a common challenge for infrastructure built on permafrost, leading to higher maintenance costs and reduced service life. This seminar will discuss the development of essential components for a comprehensive framework aimed at evaluating thaw settlement in permafrost regions—an important resource for northern infrastructure planning. Key highlights include a new qualitative approach for assessing thaw settlement potential using regional and national ground ice maps and inferred soil textures from geological data. A compiled dataset of thaw settlement test results, which has helped address gaps in thaw strain estimation resources, will be presented. This dataset enabled the development of new predictive tools, including methods for estimating thaw strain in coarse-grained sediments based on particle size distribution and for highly organic soils based on water content. Additionally, relying on this dataset, the seminar will cover comparative analyses of thaw settlement properties across different soil types and evaluations of existing thaw strain prediction tools. The newly developed tools and approaches, along with the insights gained, will inform the creation of the final framework, contributing to designing resilient infrastructure in permafrost regions.

By Tristan MacLean, ago

Seminar – 13 November – Modelling the nitrogen cycle of mosses across the boreal forest.

Rose Lefebvre will be presenting Modelling the nitrogen cycle of mosses across the boreal forest.

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

Mosses are common ground cover species in the boreal forest. They can influence different components of the ecosystem, such as the ground thermal regime due to their insulating properties, and the nitrogen cycle through biological nitrogen fixation. Mosses are not always included in terrestrial biosphere models, which are used to make climate projections. The Canadian Land Surface Scheme Including Biogeochemical Cycles (CLASSIC) was modified with the goal of improving productivity simulations across the North American boreal forest. Feather mosses and the nitrogen cycle of mosses were implemented in CLASSIC. The model was validated by comparing observation data against model output at eight sites. The sites range from being near the southern limit of permafrost to being in the continuous permafrost zone. Once validated, the model was run across the North American boreal forest.

By Tristan MacLean, ago

Seminar – 16 October – Performance of Drilling Waste Sumps, Western Arctic Canada.

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

Date: 16 October 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, ago

Seminar – 18 September – Development and demonstration of a statistical ranking framework for ground temperature models, tailored towards permafrost environments.

Hannah Macdonell will be presenting Development and demonstration of a statistical ranking framework for ground temperature models, tailored towards permafrost environments.

Date: 18 September 2024
Time: 13:00-14:00 Eastern Time
Location: Zoom (details are posted in our Teams site).

Models used to simulate permafrost variables such as ground temperature are important tools for understanding the current state and future conditions of permafrost. However, few objective methods of establishing model accuracy exist for permafrost environments. Additionally, models often range in their performance given different conditions such as terrain type or seasonality. Hannah will be presenting her master’s research that looked at (1) identifying patterns in ground-temperature model performance under different testing conditions and (2) developing a quantitative measure of ground-temperature model performance in permafrost zones.

By Tristan MacLean, ago

Seminar Videos – Ice-Wedges of the Hudson Bay Lowlands and Precise Change Detection with Airborne InSAR & Optical Photogrammetry in Active Permafrost Regions.

The NSERC PermafrostNet seminar videos – Ice-Wedge Volume, Distribution, and Development in the Barrens of the Hudson Bay Lowlands, Northern Manitoba et Precise Change Detection with Airborne InSAR and Optical Photogrammetry data in permafrost regions are now available.

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

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.

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.

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, ago

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

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, 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, ago