Name
The Role of Suprapermafrost Taliks on Groundwater Storage, Flow, and Recharge within Discontinuous Permafrost
Date & Time
Wednesday, May 27, 2026, 2:45 PM - 3:00 PM
Description
Northwestern Canada is one of the most rapidly warming regions on Earth, leading to permafrost thaw and increased subsurface connectivity. To investigate suprapermafrost talik facilitated groundwater storage, recharge, and flow, four study sites consisting of unburned and burned peatlands and mineral soils were monitored from 2022-25 near Whatì, Northwest Territories. Taliks were identified using repeat frost probe measurements, thermistors, and Electrical Resistance Tomography surveys (<100-150 Ω.m). Taliks at the burned and unburned plateau sites were laterally extensive and thickened in topographic depressions. Burned mineral sites exhibited thicker and more laterally extensive taliks than unburned sites. Continuous groundwater temperature monitoring indicated peatland taliks were non-cryotic, whereas mineral soil taliks were cryotic. Assessment of continuous water level measurements and δ2H and δ18O analysis indicated Talik recharge was from recent precipitation at all sites. Continuous nested well water-level data was used to calculate vertical and horizontal groundwater fluxes at peatland sites. Vertical gradients at peatland sites revealed groundwater discharge from underlying mineral soils into the peat over winter, with gradient reversal and recharge into the mineral soil commencing at freshet and throughout summer. At mineral soil sites, differential seasonal thaw rates between upslope coarse-grained and the instrumented fine-grained soils delayed lateral connectivity, producing a fall water-level rise unrelated to rainfall. Horizontal groundwater fluxes at peatland sites increased during frost table formation, accelerating advective permafrost thaw. Findings from this research provides insights into how suprapermafrost taliks are facilitating year-round groundwater storage and flow that can increase landscape hydrologic connectivity and rates of permafrost thaw.
Location Name
McInnes Room
Full Address
Dalhousie University
Halifax NS
Canada
Halifax NS
Canada
Session Type
Oral Presentation
Abstract ID
275
Speaker Organization
McGill University
Session Name
H2 (2 of 3)
Co-authors
Stephanie Wright, Queen's University
Seamus Daly, Aurora Research Institute
Jeffrey McKenzie, McGill University
Presenting Author
Rachel Lackey, McGill University