| Titre | Mechanisms, volumetric assessment, and prognosis for rapid coastal erosion of Tuktoyaktuk Island, an important natural barrier for the harbour and community |
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| Auteur | Whalen, D ;
Forbes, D L; Lim, M; Fraser, P; Kostylev, V; Nedimovic, M;
Stuckey, S |
| Source | Canadian Journal of Earth Sciences 2022 p. 1-60, https://doi.org/10.1139/cjes-2021-0101  Accès ouvert |
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| Année | 2022 |
| Séries alt. | Ressources naturelles Canada, Contribution externe 20210176 |
| Éditeur | Éditions Sciences Canada |
| Document | publication en série |
| Lang. | anglais |
| DOI | https://doi.org/10.1139/cjes-2021-0101 |
| Media | papier; en ligne; numérique |
| Formats | pdf |
| Province | Territoires du Nord-Ouest |
| SNRC | 107C/07 |
| Région | Tuktoyaktuk |
| Lat/Long OENS | -134.0000 -133.0000 69.5000 69.2500 |
| Sujets | érosion; pergélisol; climat arctique; climat; Changement climatique; effets cumulatifs; Communauté; géologie de l'environnement; Santé et sécurité; Nature et environnement |
| Illustrations | cartes de localisation; coupes transversales, stratigraphique; photographies; graphiques; profils; histogrammes |
| Programme | Géosciences de changements climatiques Infrastructure côtière |
| Diffusé | 2022 08 04 |
| Résumé | (disponible en anglais seulement)
The coastline of the Inuvialuit Settlement Region (ISR) in the Mackenzie -Beaufort region of the western Canadian Arctic is characterised by rapid erosion of
ice-bonded sediments with abundant excess ground ice, resulting in widespread thermal and mechanical process interactions in the shore zone. Coastal communities within the ISR are acutely aware of the rapidly eroding coastline and its impacts on
infrastructure, subsistence activities, cultural or ancestral sites, and natural habitats. Tuktoyaktuk Island is a large natural barrier protecting the harbour and surrounding community from exposure to waves. It is threatened by coastal erosion, a
better understanding of which will inform adaptation strategies. Using historical and recent aerial imagery, high-resolution digital elevation models, cliff geomorphology, stratigraphy, and sedimentology, including ground-ice content, this study
documents erosional processes, recession rates, volume losses and sediment delivery since 1947, and projected into the future. Erosion along the northwest-facing (exposed) cliff, primarily by thermo-abrasional undercutting and block failure, has
accelerated since 2000 to a mean of 1.8 ± 0.02 m/yr, a 22% increase over the previous 15 years and 17% faster than 1947-2000. Lower recession rates on the harbour side of the island increased more than two-fold. Projection of future shoreline vectors
by extrapolation, using the post-2000 accelerated coastal recession rates at 284 transects, points to breaching of this vital natural harbour barrier by 2044, after which rapid realignment is expected to occur as the new inlet evolves. Further
acceleration of rates, as seems highly likely, brings the breaching date closer. |
| Sommaire | (Résumé en langage clair et simple, non publié)
Cet article examine l'érosion à long terme de l'île Tuktoyaktuk, qui sert de brise-lames naturel pour la communauté de Tuktoyaktuk et le port de
Tuktoyaktuk. Ici, nous analysons l'imagerie aérienne (de 1947 à aujourd'hui) pour établir que le taux de recul côtier annuel moyen sur l'île Tuktoyaktuk est de 1,8 m/an. Si ce taux d'érosion se poursuit, ce port naturel vital serait exposé à l'action
des vagues dans les 23 ans suivant la rupture de l'île. Une meilleure compréhension de la dynamique des sédiments à court et à long terme de l'île Tuktoyaktuk dans cet environnement en évolution rapide est essentielle pour faire des projections
précises du changement futur et développer des stratégies d'adaptation appropriées. |
| GEOSCAN ID | 328619 |
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