2024 AGM and Arctic Change Conference

Daniel Fortier

Titre: Have you developed a ground ice addiction? Theme 1 can help you fix your cravings.

Toni Lewkowicz

Titre: CPERS database.

 Trevor Lantz

Titre: Developing an Overview of Permafrost Monitoring Methods. Update from the Theme 2 working group.

Stephan Gruber

Titre: Progress on simulating transient permafrost change.

Oliver Sonnentag

Titre: Theme 3 (Modelling) update.

Jackie Ziegler

Titre: Theme 4 Project Update: Permafrost Hazard Interviews across Canada.

Brian Moorman

Titre: Early detection and high resolution monitoring of terrain disturbance.

Melissa Lafrenière

Titre: Impacts of thawing permafrost on water systems.

Pascale Roy-Léveillée

Titre: A brief overview of theme 4 and some thoughts on permafrost geohazard research.

Jocelyn Hayley

Titre: Impacts of Permafrost Thaw on Linear Infrastructure.

Chris Burn

Titre: Permafrost thaw adaptation and mitigation.

Brian Moorman

Titre: Inland impact of arctic coastal erosion: ice wedges and hydrology.

The direct impacts of arctic coastal erosion in ice-rich permafrost areas are obvious and dramatic. Rapid coastal alteration, dumping of massive amounts of sediment into the ocean, and retrogressive thaw slumps are all obvious signs of coastal retreat in ice-rich permafrost areas. However, less obvious impacts are experienced in the terrestrial environment many hundreds of metres inland from the coast. Small changes to the coastline can result in large changes to the local hydrological baselevel and the impact that has on the hydrological system and geomorphic features such as ice wedge polygons.

For this study we used very high resolution drone derived digital elevation models and orthophotos to examine the impacts of coastal retreat on the hydrological and geomorphological systems near Revneset, Svalbard. This area features a series of beach ridges with mature ice wedge polygons between them extending right up to the coastline. The overall slope of the terrain causes all the surficial runoff to flow through the ice wedge troughs to the sea. In areas where the local baselevel, controlled by coastal erosion, has been lowered, faster flowing water is resulting in the ice wedges eroding out and the nearby landscape drying out. This appears to have impacted both the flora and fauna of the region.

The results of this study demonstrate how local coastal dynamics can have a broader and more significant impact on inland regions surrounding the coast.

Daniel Fortier

Titre: Early Pleistocene glacier ice preserved in permafrost in the eastern Canadian Arctic: the oldest remnant of glacier ice in the northern hemisphere?

Buried glacier ice is widespread near the margin of formerly glaciated landscapes. It can be preserved in permafrost environments for thousands to millions of years, and thus represents a unique source of paleogeographical, paleoenvironmental, and paleoclimatological information. On Bylot Island, remnants of glacier ice were exposed in headwalls of thaw slumps located on the edge of an upland plateau. This deposit sits on top of a 2.8-2.4 Ma fossil forest deposit. We used sedimentological, cryostratigraphic, and geochemical techniques together with radiocarbon, and paleomagnetic dating to determine the origin and age of the buried ice and surrounding sediments. The ice presented striking similarities with cryofacies, deformation features, and δ¹⁸O values of englacial ice and debris-rich basal-ice layers observed at the base of contemporary glaciers. The cryostratigraphic and isotopic properties of the pure ice with large, interlocked ice crystals and few sediment inclusions are suggestive of an englacial origin (firnification), whereas those of the alternating layers of debris-rich and debris-poor ice are more consistent with a basal glacier ice origin. Paleomagnetic records of the glacio-fluvial sediments overlying the buried glacier ice recorded a normal-reversed-normal magnetic polarity, suggesting that the ice was in place since at least 0.773 Ma. As such, it represents the oldest glacier ice preserved in ice-free Arctic landscapes, and the earliest evidence of a Pleistocene glaciation in the eastern Canadian Arctic Archipelago. The presence of this buried ice near the surface also demonstrates the very strong resilience of cold Arctic permafrost to past climate warming.

Emma Street, Ernie Francis and Irma Cardinal

Titre: Exploring Traditional Knowledge of Permafrost Change in the Gwich’in Settlement Area and Inuvialuit Settlement Region.

Temperature increases four times faster than the global average are transforming Arctic landscapes at unprecedented rates. These changes drastically impact permafrost, ground that remains at or below 0°C for two or more years, and threaten the infrastructure, ecosystems, and socio-cultural elements of Arctic communities reliant upon it. This project explores the extent and significance of permafrost degradation in the Gwich’in Settlement Area and the Inuvialuit Settlement Region in the western Canadian Arctic. By way of Two Eyed Seeing and community-driven participatory research methodologies, this project in collaboration with the Inuvialuit Game Council, Inuvialuit Joint Secretariat, Gwich’in Renewable Resources Board, Gwich’in Department of Culture and Heritage, and community members, documents Gwich’in and Inuvialuit Traditional Knowledge pertaining to permafrost and observed changes in community. This presentation presents the methodologies behind this research and the results of 110 interviews completed among the eight communities of Paulatuk, Sachs Harbour, Tuktoyaktuk, Ulukhaktok, Fort McPherson, Tsiigehtchic, Aklavik, and Inuvik. Findings from this work highlight community relationship and engagement with permafrost and community concerns including those related to traditional travel route access, subsistence activities, and infrastructure. It is anticipated that these findings will contribute to permafrost knowledge and help amplify mitigation and adaptation needs and potential solutions for Gwich’in and Inuvialuit communities – and those beyond – facing permafrost thaw.

Frederic Brieger

Titre: Permafrost terrain disturbance mapping and susceptibility modeling in the Nacho Nyäk Tagé (Stewart River) watershed, Yukon.

The Nacho Nyäk Tagé (Stewart River) watershed in the traditional territory of the First Nation of Na-Cho Nyäk Dun (central Yukon) is underlain by extensive discontinuous permafrost and locally highly sensitive to thaw. In addition to impacts from climate change to its ecology, geomorphology, and hydrology, this culturally important area is pressured by mining activities and their environmentally harmful practices. Timely community-led land-use planning is necessary to develop effective management, conservation, and adaptation strategies. This project aims to contribute assessments on the distribution and susceptibility towards permafrost terrain disturbances (PTDs) in the watershed to the undergoing land-use planning process.

A total of 277 PTDs including 80 retrogressive thaw slumps (RTSs) were mapped in satellite imagery to understand the current spatial distribution of thaw-induced geohazards in the watershed. PTDs are indicators of sensitive permafrost terrain that is likely to respond strongly to climate change. RTSs in particular are indicative of thawing ice-rich permafrost and have increased in frequency and activity. Along the banks of Nacho Nyäk Tagé, they are typically associated with ice-rich glaciolacustrine sediments or tills, as validated by field observations.

Terrain susceptibility towards PTDs was modelled using random forest machine learning at a 16 m spatial resolution and revealed distinct spatial patterns related to the physiography and climatic history of the region. Tenfold cross-validation resulted in an average AUROC of 0.89, indicating high accuracy of model predictions. RTSs are predominantly found on gentle, northwest to northeast-facing slopes and riverbanks consisting of fine-grained glaciogenic sediments from the late McConnell glaciation.

Gabriel Karam

Titre: A Simulated Study of Ice-Wedge Behaviour at Illisarvik, NWT, and Salluit, QC, Using XFEM.

Ice wedges comprise a large portion of the massive ice found in the continuous permafrost zone, impacting the hydrology, subsidence, and ecosystem of the surrounding terrain. Many field studies have investigated the different aspects of ice wedges — namely cracking predictors, geomorphological characteristics, and wedge-ice distribution. However, field data and longitudinal studies on cracking events are scarce due to the low frequency of ice-wedge cracking. Here, numerical methods can complement field studies and provide new insight into the formation process and other important variables such as estimated wedge-ice volume. 

We propose a case study using an existing 2-D numerical model to study ice-wedge cracking at two contrasting locations. First, Illisarvik, NWT, is the only studied site of lake drainage and the subsequent creation of incipient wedges. These wedges have a unique shape compared to their more-mature counterparts. Second, Salluit in the north of Quebec is a site of cold temperatures, frequent cracking, and mature wedges with defined morphology. 

Our model uses the extended finite-element method (XFEM) to explicitly simulate cracks in soil. Soil properties and climate data are taken as inputs, which can be derived from either observed meteorological data or reanalysis products. This approach is versatile and can be employed at any location with appropriate data. Results from both sites will be compared to existing field studies to evaluate model performance and draw conclusions regarding the formation and growth of ice wedges. 

Hosein Fereydooni

Titre: Spectral Induced Polarization can reduce the ambiguity of detecting ground ice in warm permafrost.

Electrical Resistivity Tomography (ERT) is a widely used technique for identifying ground ice in permafrost regions. While it usually distinguishes ground ice due to its high resistivity compared to unfrozen materials, some subsurface conditions and configurations can cause ambiguity. In contrast, Spectral Induced Polarization (SIP), which leverages the polarization properties of ground ice, potentially offers less ambiguous identification.

In this study, we compare published ERT and new SIP results near a retrogressive thaw slump in Yukon, Canada. The SIP measurements were conducted in the winter of 2023, using frequencies ranging from 1.46 Hz to 40 kHz. The ERT measurements were carried out in 2019, with both surveys employing a dipole-dipole array along the same survey line. While the ERT results showed no clear evidence of ground ice, the SIP real and imaginary results at 40 kHz and the Resistivity Frequency Effect (RFE) indicate the presence of ice within the same locations and depths.

The findings suggest that ground ice may exist in regions with resistivity as low as 100 Ωm (despite ground ice typically having higher resistivity), likely due to fine-grained materials with higher liquid water content. Since ERT relies solely on resistivity, it can lead to misinterpreting warm and ice-rich clay, sand, or silt (low-resistivity materials) as being unfrozen, SIP may offer additional insight. As a new technique, however, procedures and tools for SIP survey design and execution, as well as methods for processing and interpretation, are demanding and less well developed than for ERT.

Nick Brown

Titre: Rapid lowering of the top of permafrost : causes, forecasting, and implications for monitoring.

Active layer thickness is an important variable in permafrost regions. It affects biogeochemical processes, water transport, and ground stability. It is also one of three products used to track permafrost as part of the essential climate variable framework. 

Global observations of active layer thickness show increases at typical rates on the order of centimetres per year. However, in warm permafrost, much higher rates are observed, up to an order of magnitude greater. Several explanations have been provided to explain this discrepancy such as the partitioning of latent vs. sensible heat, an increase in the thermal gradient, and the formation of taliks.

We investigate two additional explanations: First, by approaching isothermal conditions in thawing permafrost, heat transport deeper into the ground is diminished. Consequently, a greater proportion of the downward heat flux at the top of permafrost is available for phase change. Second, that in very dry permafrost, accelerated . To test this, we simulate 120 years of warming in different ground conditions and climates using the numerical model FreeThaw1D to recreate this phenomenon. We demonstrate how the acceleration of active layer deepening is connected to the presence and loss of ground ice in permafrost. 

A stronger understanding of the processes that lead to rapid active layer deepening will be beneficial for forecasting when it will occur and interpreting changes in ground thermal regime.

Samuel Gagnon

Titre: Formation of thermo-erosional gullies in the ice-rich transition zone of marine sediments.

Thermo-erosional gullies are one of the most widespread forms of permafrost degradation in the Arctic. Their formation, development, and stabilization have been reported in ice-wedge polygonal terrain where ice-wedge degradation by thermo-mechanical processes catalyses the development of gully networks. However, thermo-erosional gullies forming in the absence of polygonal networks can also develop, though they have yet to be reported. This study aimed to characterize such gullies and provide an explanation for their mechanism of formation in a marine terrace along the coast near Ikaluktutiak (NU,Canada). The stratigraphy of near-surface permafrost is characterized by a layer of ice-poor sandy sediments (30-50 cm) overlying marine clay of varying ice contents. The top (~1m) of the marine clay forms an ice-rich transition zone (volumetric ice content >75%) that overlies marine sediments with much lower ice contents (<20%). Nineteen thermo-erosional gullies forming perpendicular to the coast have been characterized using field measurements, photographs from automated cameras, and drone surveys. The depths and widths of the gullies generally ranged from 2 to 3m, while the lengths of the main channels varied between 4m and 50m. Of the nineteen gullies identified within a 200-m section, sixteen gullies were active and retreating inland, and showed signs of ground subsidence due to groundwater flow (e.g., overhangs, tunnels). We suggest that gullying is initiated in the spring when the active layer reaches the interface between the sand and marine clay layers where groundwater flow causes melting of the ice in the transition layer and subsidence of the surface layers.

Tabatha Rahman

Titre: Permafrost landscape evolution in the Barrens of northern Manitoba.

The Barrens are a 14,200 km² area of polygonal tundra in the continuous permafrost zone of northern Manitoba. Rapid climatic warming in the Barrens is affecting the Hudson Bay Railway, a crucial transportation infrastructure built on permafrost. However, terrain changes expected with continued permafrost warming and thaw are not well defined for the Barrens, where little is known about ground ice conditions, permafrost thermal regimes, or thermokarst dynamics. This research examined ground-ice conditions and controls on thermokarst evolution to better predict future landscape changes in the Barrens. Objectives were to 1) characterize permafrost and ground-ice conditions to assess vulnerability to thaw and thermokarst; 2) inventory recent geomorphological changes to infer future landscape evolution; and 3) develop a conceptual model of the expected geomorphological evolution along the railway. Geomorphological changes across the Barrens were assessed from historical aerial photographs and satellite imagery from 1927 to 2024. In representative areas, 45 permafrost cores were extracted extending up to 5.5 m beneath the surface. Organic layer thickness, sediment texture, and thaw consolidation potential were measured. Snow conditions and ground thermal regimes were assessed. Preliminary results indicated four categories of change: burning, wetting, greening, and drainage. Ice-rich permafrost is insulated from the atmosphere by a peat layer 110 to 240-cm thick, leading to a thermal offset of up to -3.1 °C. Thermokarst was most widespread where peat was thinnest and near-surface ice content was relatively high. Pool ice above wedge ice indicated post-disturbance permafrost recovery at sites that burned before 1947 and in 2012.

Adam Kirkwood

Titre: How does accounting for spatial variability impact estimates of mercury storage in the Hudson Bay Lowlands (HBL)?

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Alexandre Chiasson

Titre: A Standardized Mapping Nomenclature for Permafrost and Thermokarst Features

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Danielle Chiasson

Titre: Post-drainage evolution of Wolverine Lake, Old Crow Flats, Yukon.

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Frederic Brieger

Titre: Settling lands: Revealing spatiotemporal patterns of ground movement under community infrastructure in Mayo, Yukon.

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Galina Jonat

Titre: An impact-centric framework for preparing and selecting climate model data for permafrost studies.

Léa Cornette

Titre: Navigating the Arctic Firescape: Biogeochemical Cycles of Soil Nutrients and Indigenous Perspectives in the Inuvialuit Settlement Region.

Muhammad Umair

Titre: Characterizing carbon and water fluxes in the arctic boreal forest using plant hydraulics parameterization in the presence and absence of permafrost: a modelling approach.

Nick Brown

Titre: Interpreting and quantifying temperature-derived thaw metrics as indicators of permafrost change.

Olivia Meier-Legault

Titre: Improving permafrost thaw detection in Canada using multiple boreholes and temperature-derived metrics.

Pia Blake

Titre: Effects of Snow and Surface Material on Surface Offset of Canadian Steep Slopes.

Victor Pozsgay

Titre: Summarizing Transient
Permafrost Ensemble
Simulations for Investigating
Climatic Influences on Slope
Failures.

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