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TitleNew information on permafrost thermal state in the Alaska Highway Corridor, Yukon
AuthorSmith, S; Lewkowicz, A G; Ednie, M; Bevington, A; Blais-Stevens, A; Bonnaventure, P
SourceArctic Change 2014, poster abstracts; 2014 p. 185
Alt SeriesEarth Sciences Sector, Contribution Series 20140230
MeetingArctic Change 2014; Ottawa; CA; December 8-12, 2014
Mediapaper; on-line; digital
File formatpdf
NTS105D/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
AreaAlaska Highway Corridor
Lat/Long WENS-141.0000 -134.0000 62.7500 60.7500
Subjectssurficial geology/geomorphology; engineering geology; permafrost; freezing ground; ground ice; ground temperatures; thermal analyses; pipeline feasibility studies; pipelines; climate; Cenozoic; Quaternary
ProgramRisk Analysis, Climate Change Geoscience
LinksOnline - En ligne
AbstractThe 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.
Summary(Plain Language Summary, not published)
Instrumented field sites established 2011-13 along the Alaska Highway corridor between Whitehorse and the Alaska border, provide new information on current permafrost conditions. This information is required for terrain sensitivity assessments and planning northern development (eg. pipeline, highway) to ensure infrastructure and environmental integrity. Results indicated that permafrost in this section of the corridor is generally warm (temperatures above -1.5°C but is as cold as -3°C near the Alaska border. Comparison with ground temperatures measured in the late 1970s indicates that permafrost temperatures may have increased over the last 30 years.