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TitreNew information on permafrost thermal state in the Alaska Highway Corridor, Yukon
AuteurSmith, S; Lewkowicz, A G; Ednie, M; Bevington, A; Blais-Stevens, A; Bonnaventure, P
SourceArctic Change 2014, poster abstracts; 2014 p. 185
Année2014
Séries alt.Secteur des sciences de la Terre, Contribution externe 20140230
RéunionArctic Change 2014; Ottawa; CA; décembre 8-12, 2014
Documentlivre
Lang.anglais
Mediapapier; en ligne; numérique
Formatspdf
ProvinceYukon
SNRC105D/13; 105D/14; 115A/13; 115A/14; 115A/15; 115A/16; 115B/16; 115F/15; 115F/16; 115G/01; 115G/02; 115G/05; 115G/06; 115G/07; 115G/11; 115G/12; 115G/13; 115K/02; 115K/07; 115K/10
Lat/Long OENS-141.0000 -134.0000 62.7500 60.7500
Sujetspergélisol; congélation du sol; glace fossile; températures au sol; analyses thermiques; études de faisabilité du pipeline; pipelines; climat; géologie des dépôts meubles/géomorphologie; géologie de l'ingénieur; Cénozoïque; Quaternaire
ProgrammeL'analyse des risques, Géosciences de changements climatiques
LiensOnline - En ligne
Résumé(disponible en anglais seulement)
The Alaska Highway Corridor traverses the discontinuous permafrost zone of the southern Yukon. Permafrost characteristics were investigated in the corridor over 30 years ago to support a pipeline proposal but little information is available on current ground thermal conditions. Air temperatures in the region have increased 0.4-0.5°C per decade since the 1970s and recent studies in the corridor indicate that thawing of permafrost has occurred over the last four decades (e.g. James et al. 2013). Recent proposals for construction and operation of a natural gas pipeline and the need to develop climate change adaptation strategies for existing highway infrastructure has stimulated the acquisition of updated information on permafrost conditions.

Between 2011 and 2013, nineteen boreholes up to 10 m deep were instrumented with temperature cables in the section of the corridor west of Whitehorse in order to characterize the ground thermal conditions. These boreholes complement those instrumented during the International Polar Year elsewhere in the central and southern Yukon.

The ground thermal data collected indicates that permafrost is generally warm (above -1.5°C) in this section of the corridor. However, colder permafrost (-3°C) was found in the immediate vicinity of the Alaska border in an area predicted by Bonnaventure et al. (2012) to be continuous permafrost. Data records are too short to determine if there is any trend in permafrost temperatures. However, a comparison of recent ground temperatures with those collected by the Geological Survey of Canada in the late 1970s indicates that warming of permafrost has occurred of a similar magnitude as that observed elsewhere in northwestern Canada (Dugay et al. in prep).
The ground thermal data collected from these new monitoring sites have been compiled into a digital database along with data obtained from other instrumented boreholes in the central and southern Yukon. These data facilitate a better understanding of regional permafrost conditions and support improved assessments of terrain sensitivity including models of landslide susceptibiltiy. The publicly available data can also be utilized for climate change adaptation planning and to support infrastructure design in the region.
Résumé(Résumé en langage clair et simple, non publié)
Des sites instrumentés établis en 2011-2013 le long du corridor de la route de l'Alaska entre Whitehorse et la frontière de l'Alaska permettent d'obtenir de nouvelles données sur les conditions actuelles de pergélisol. Ces données sont nécessaires pour effectuer un certain nombre d'évaluations de la vulnérabilité du terrain et planifier le développement du Nord (p. ex. construction de pipelines et de routes) afin d'assurer l'intégrité de l'infrastructure et de l'environnement. Les résultats montrent que le pergélisol dans la présente section du corridor est relativement chaud (températures au-dessus de -1,5 °C, mais pouvant atteindre jusqu'à -3 °C près de la frontière de l'Alaska). Si l'on compare avec les températures au sol mesurées à la fin des années 1970, les températures de pergélisol semblent avoir augmentées au cours des 30 dernières années
GEOSCAN ID295214