| Title | Regional assessment of the occurrence of taliks below Arctic lakes |
| |
| Author | LeBlanc, A -M ;
Chartrand, J; Smith, S |
| Source | ArcticNet 2021 Annual Scientific Meeting, abstracts; Arctic Science vol. 8, no. 1, 2022 p. 133, https://doi.org/10.1139/as-2022-0002  Open Access |
| Image |  |
| Year | 2022 |
| Alt Series | Natural Resources Canada, Contribution Series 20210261 |
| Publisher | Canadian Science Publishing |
| Meeting | ASM2021 - ArcticNet Annual Scientific Meeting 2021; December 6-10, 2021 |
| Document | serial |
| Lang. | English |
| Media | paper; on-line; digital |
| Related | This publication is related to Regional assessment of the
presence of taliks below Arctic lakes, Nunavut |
| File format | pdf |
| Province | Nunavut |
| NTS | 46D; 46E; 46F; 46L; 46M; 46N; 55; 56; 65A; 65B; 65G; 65H; 65I; 65J; 65O; 65P; 66A; 66B; 66G; 66H; 66I; 66J; 66O; 66P |
| Lat/Long WENS | -100.0000 -85.0000 68.0000 60.0000 |
| Subjects | surficial geology/geomorphology; environmental geology; hydrogeology; Nature and Environment; Science and Technology; Economics and Industry; permafrost; ground ice; periglacial features; talik; surface
waters; lakes; lake water depths; topography; groundwater; groundwater flow; groundwater pollution; mining; mine development; transport mechanisms; mine waste products; waste disposal sites; models; statistical analyses; ArcticDEM; Climate change;
Mining industry; Digital elevation data; Geographic information systems; cumulative effects |
| Program | Climate Change
Geoscience Permafrost |
| Released | 2022 02 18 |
| Abstract | In continuous permafrost regions, taliks (areas of unfrozen ground) occur mainly beneath large and deep lakes (>2 m depth) that do not freeze to their bottoms. Open taliks connected to regional
groundwater can affect the development of mine projects by providing pathways for mine water inflow or contaminant transport. It is, therefore, important to determine which lakes are potentially underlain by open taliks. A methodology is presented to
assess the potential for talik occurrence at a regional scale. The methodology considers lake geometry, lake terrace width, surrounding landscape topography, ground thermal conditions, and lake water temperature. Lakes are classified as circular or
elongated using geographic information system analysis. High resolution imagery is used to classify the center pool and the average terrace width of each lake. The ArcticDEM is used to extract topographical variables surrounding lakes to run
predictive models of maximum lake depth and to determine if the center pool of each lake is shallow (<4 m) or deep (greater than or equal to 4 m) to subsequently attribute a lake water temperature. Lake temperature values for central pools and
terraces and the geothermal gradient and ground surface temperature are based on literature values from reports submitted for Environmental Impact Assessments. All parameters are combined in equations defined for circular or elongated lakes in a
semi-infinite horizontal plane, with the assumption of steady-state conditions. Ranges of values for lake terrace and ground surface temperatures and geothermal gradient are introduced in equations to cope with uncertainty. This allows classification
of each lake as 'no open talik', 'potential open talik', and 'open talik'. The methodology is validated with known maximum lake depths, bathymetric contours, and confirmed occurrence of open taliks. Results for mineral resource development areas in
Nunavut are provided. |
| Summary | (Plain Language Summary, not published)
Open taliks, areas of unfrozen ground, are mainly found beneath large and deep lakes that do not freeze to their bottom. Open taliks connected to
regional groundwater can affect the development of mine projects by providing pathways for mine water inflow or contaminant transport. This study presents a methodology to assess the occurrence of taliks below Arctic lakes at a regional scale. The
methodology uses existing information on lakes and their surrounding ground and additional information from high-resolution satellite imagery and a digital elevation model. Results, under the form of regional maps, for mineral resource development
areas in Nunavut are provided. |
| GEOSCAN ID | 328888 |
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