| Titre | Temporal and spatial changes of permafrost in Canada since the end of the Little Ice Age |
| |
| Auteur | Zhang, Y ; Chen,
W; Riseborough, D W |
| Source | Journal of Geophysical Research vol. 111, D22103, 2006, 14p., https://doi.org/10.1029/2006JD007284 |
| Image |  |
| Année | 2006 |
| Séries alt. | Secteur des sciences de la Terre, Contribution externe 2005872 |
| Éditeur | Wiley-Blackwell |
| Document | publication en série |
| Lang. | anglais |
| DOI | https://doi.org/10.1029/2006JD007284 |
| Media | papier; en ligne; numérique |
| Formats | pdf |
| Province | Alberta; Colombie-Britannique; Canada; Manitoba; Ontario; Territoires du Nord-Ouest; Nouvelle-Écosse; Nunavut; Yukon; Saskatchewan; Québec; Terre-Neuve-et-Labrador |
| SNRC | 2; 12; 13; 14; 15; 16; 22; 23; 24; 25; 26; 27; 28; 29; 32; 33; 34; 35; 36; 37; 38; 39; 42; 43; 44; 45; 46; 47; 48; 49; 52; 53; 54; 55; 56; 57; 58; 59; 62; 63; 64; 65; 66; 67; 68; 69; 72; 73; 74; 75; 76; 77;
78; 79; 82; 83; 84; 85; 86; 87; 88; 89; 92; 93; 94; 95; 96; 97; 98; 99A; 102; 103; 104; 105; 106; 107; 114; 115; 116; 117 |
| Lat/Long OENS | -141.0000 -56.0000 84.0000 48.0000 |
| Sujets | pergélisol; fluctuations climatiques; climat; regimes thermiques; établissement de modèles; températures au sol; talik; géologie des dépôts meubles/géomorphologie; Nature et environnement;
Quaternaire |
| Illustrations | croquis cartographiques; analyses |
| Programme | Réduction des risques dus aux aléas naturels |
| Diffusé | 2006 11 16 |
| Résumé | (disponible en anglais seulement)
Air temperature at northern high latitudes has increased at a higher rate than the global mean during the 20th century. Climate warming could induce permafrost
degradation, which may have important impacts on hydrological, ecological, and biogeochemical processes, and on northern communities and infrastructure. To assess the effects of climate change on permafrost, a process-based model of Northern
Ecosystem Soil Temperature (NEST) was developed and utilized to simulate the ground thermal regime of the Canadian landmass at a resolution of a half-degree latitude-longitude since the end of the Little Ice Age (circa 1850). The simulated southern
boundary of the permafrost for recent decades is similar to that of the current published map, and simulated active-layer thickness and the depth to permafrost base are comparable to the site measurements. This long-term simulation shows that climate
change since the end of the Little Ice Age, especially during the 20th century, has induced degradation of permafrost in most of Canada: From the 1850s to the 1990s, the area underlain by permafrost was reduced by 5.4%; for those areas where
permafrost existed in all the years throughout the period 1850-2002, the mean depth to the base of permafrost decreased (became shallower) by 3 m; the mean active-layer thickness increased by 0.21 m, or 34%; and the mean depth to permafrost table
increased by 0.39 m. The simulation also shows that supra permafrost-taliks were formed in the southern margins of the permafrost region, and these taliks became larger and more common with climate warming. |
| GEOSCAN ID | 222060 |
|
|