In 2007, a permafrost outreach program was initiated in Yukon, Canada by installing long-term permafrost monitoring stations near public schools in Whitehorse, Faro, Ross River, Dawson, Old Crow and Beaver Creek. Shallow boreholes were drilled near participating schools, and data loggers were installed to measure hourly air and ground temperatures at a variety of depths. Frost tubes were also installed in fall 2008 to start monitoring seasonal freezing and thawing trends in the active layer. School students are actively engaged with field data collection and interpretation of results posted on a central website. The program also provides baseline data that can be used to characterize local permafrost conditions and detect long-term changes. A snapshot of current permafrost conditions is provided for each monitoring station, based on the first year of data collection.

This data set is a database of the permafrost and geothermal conditions of the oil and gas deposits of Western Siberia. Data were taken from 736 plots, each having from one to ten wells. The data set includes soil and rock temperatures at 20, 50, 100, 200, 300, 400, 500, 1000, and 3000 meters; depth of the bedding of the top and bottom of permafrost layers; size of the thermal flows in the subpermafrost; and thickness of frozen layers and underlying thawed layers. Additional information includes the geographical coordinates of the sites, the air temperature, permafrost-geothermal geological sections, maps of thermal flows, and the distribution of the temperatures at each depth (down to 5000 meters). The data are presented on the CAPS Version 1.0 CD-ROM, June 1998.

During the summer of 1969 a thermal drilling and deep ice-temperature measurement program was carried out on the Fox Glacier, Yukon Territory. The thermal drilling resulted in seven instrumented holes at six locations on the glacier, three reaching bedrock. Temperature measurements indicated that the glacier was below the pressure-melting point throughout and that memory of a disturbed thermal regime existed. Estimates of geothermal heat flow were determined and an anomalous value of 4.73 µcal/cm² sec obtained. Bottom temperature models were developed which indicate the possibility of basal melting.

Four groups of borehole data from the Qinghai-Xizang (Tibet) Plateau are presented. 1) Boreholes at three sites, with sand surface, natural surface, and near a sand dune, at 66 Road Station - 1994 and 1995 measurements to about 17 meters. 2) Borehole temperatures at Borehole CK123 - 1979, 1984, 1994 measurements to 60 meters. 3) Borehole temperatures at five sites in Fenghuoshan Station area - 1962, 1967, 1980, 1984, 1989, 1994, 1995 measurements to 35 meters. 4) Boreholes at Xidatan-Kunlun Pass area - 1994 and 1995 measurements to 17.5 meters; 1994 and 1995 measurements to 25 meters; and 1975, 1976, 1979, 1985, 1989, 1994 and 1995 to 30 meters. Data provided by Wang Shaoling and Cheng Guodong, Lanzhou Institute of Glaciology and Geocryology. Some of these data are presented on the CAPS Version 1.0 CD-ROM, June 1998.

The effects of permafrost degradation in Yukon have serious negative implications for the structural integrity of vertical infrastructure. This is especially pertinent for critical buildings such as hospitals, schools, etc., in small communities that are situated on top of warm, ice-rich permafrost. Projections of mean annual air temperature over the next few decades, based on regional climatic models, indicate that air temperature will rise, hastening the thaw of permafrost. The combination of rising of air temperatures and buildings situated on warm permafrost has prompted this investigation into the vulnerability of Yukon Government vertical infrastructure. The application of DC resistivity and ground penetrating radar in conjunction with borehole drilling indicates that in Dawson there is warm ice-rich permafrost beneath the Palace Grand Theatre; the Old Territorial Administration building is underlain by primarily unfrozen sediment; and permafrost under the St. Andrew’s Church is characterized by high variability. A deep active layer was observed at Ross River School and geophysical surveys indicate that warm water drainage from the roof is contributing to the thaw of the underlying permafrost.

Results of surficial geology investigations in Wellesley basin and the Nisling Range can be summarized into four main highlights, which have implications for exploration, development and infrastructure in the region: 1) in contrast to previous glacial-limit mapping for the St. Elias Mountains lobe, no evidence for the late Pliocene/early Pleistocene pre-Reid glacial limits was found in the study area; 2) placer potential was identified along the Reid glacial limit where a significant drainage diversion occurred for Grayling Creek; 3) widespread permafrost was encountered in the study area including near-continuous veneers of sheet-wash; and 4) a monitoring program was initiated at a recently active landslide which has potential to develop into a catastrophic failure that could damage the White River bridge on the Alaska Highway.

As part of the Canadian government’s commitment to establishing clean energy in the North, the Yukon Geological Survey is collecting subsurface temperature data near communities in the southern part of the territory. The research is a collaborative effort among federal and territorial geoscientists, universities, First Nation governments, and geothermal consultants. A major goal of the project is to determine whether ground temperatures warrant further geothermal exploration in the territory. The study also presents an opportunity for Yukon Geological Survey to educate the public about geothermal energy. This paper summarizes the methods and results of the drilling of two ~500 m geothermal temperature gradient wells. The first was drilled in the fall of 2017 in the Whitehorse area, near Takhini Hot Springs, where a surface water seep measures 46°C. The second well was drilled in winter 2018 in the Tintina fault system, near Ross River. Results to date suggest warm fluids and possible permeable rocks in the Takhini well between 450 and 500 m from surface, and a higher than average geothermal gradient of ~31°C/km in the Tintina Trench near Ross River. The results do not indicate temperatures for power generation at economic depths, however, they are encouraging enough to warrant further geothermal studies in southern Yukon.

Up to six years of data have been collected at seven stations within Yukon Geological Survey’s permafrost monitoring network between 2008 and 2013. Warm permafrost conditions (>-0.5°C) governed by latent heat effects exist at the Whitehorse, Watson Lake, Ross River School and Dawson School monitoring stations, while average permafrost temperatures in Faro are only marginally cooler at -0.6°C. Mean annual ground temperatures at the Beaver Creek and the Dawson dump forest monitoring stations are much colder at -2.9 and -2.0°C respectively. Most sites show either insignificant or very slight short term permafrost warming trends, although slight cooling is apparent at Ross River School, and rapid warming has occurred at Beaver Creek over the monitoring period. Opportunities to expand the network and collaborate with external parties operating similar monitoring stations should be further explored to facilitate more complete and representative reporting on the thermal state of permafrost in Yukon.

The methods utilized by the U.S. Geological Survey to measure subsurface temperatures have evolved considerably over the years. Although some of the early measurements were obtained using thermistor strings frozen into permafrost, the vast majority of the measurements were made in fluid-filled holes using a custom temperature sensor. A typical sensor used in Alaska prior to 1989 consisted of a series-parallel network of 20 thermistors; see Sass et al. [1971] for a more detailed description. During a logging experiment, the resistance of the thermistor network was determined using a Wheatstone bridge prior to 1967. After that time, a 4-wire resistance measurement was made using a commercial 5.5-digit multimeter (DMM). Before 1984, boreholes were logged in the 'incremental' or 'stop-and-go' modes; the vertical spacing of the measurements was typically 3-15 m. Beginning in 1984, the depth/resistance measurements were automatically stored on magnetic tape, allowing boreholes to be logged in the 'continuous' mode; the typical data spacing for the continuous temperature logs was 0.3 m (1 ft). Many of the Alaskan boreholes were re-logged several times to quantify the thermal disturbance caused by drilling the holes (see Lachenbruch and Brewer [1959]). A review of current temperature measuring techniques used by the USGS in the polar regions is given by Clow et al. [1996]. Data from 1950-1989 are included on the CAPS CD-ROM Version 1.0, June 1998.

In collaboration with the Yukon Geological Survey, the Geological Survey of Canada, and other project partners, Innovate Geothermal Ltd. performed an analysis of geoscience data in southwestern Yukon as part of an effort to better understand the potential for geothermal energy resources that, if present, could be utilized to help reduce fossil fuel use. The study area for this project is located in the vicinity of the Village of Haines Junction (Dakwäkäda) and lies between the Denali and Shakwak fault zones. The main aim of this project is to analyze and interpret a variety of pre-existing and newly acquired geological and geophysical datasets to evaluate where geothermal reservoirs may be present within the study area. A secondary aim is to propose favourable drilling locations, if warranted, for exploratory wells to collect information on subsurface temperature and permeability. The geoscience work accomplished here includes both 2D map interpretation as well as construction of a 3D geologic model that was guided by geophysical inversion modelling of gravity, magnetic and audio-magnetotelluric survey data. At a regional scale, multiple lines of evidence suggest that subsurface temperatures are above the crustal average. More importantly, a municipal water well drilled in 2002 in the Village of Haines Junction produce warm (~20 °C) water from a depth of ~350 m. This water well proves that at least one permeable sediment-hosted geothermal aquifer is present under Haines Junction. Additional geothermal aquifers within the pile of young sediment that sits atop the bedrock are likely present. However, due to a lack of deep drilling in the area, the exact location, temperature, thickness and permeability of such aquifers remains unknown. In this study, a depth-to-bedrock model has been generated to aid with the identification of favourable target areas for exploratory drilling of geothermal wells. The four areas where the top-of-bedrock is deepest have estimated depths in the range 650 to 1225 m below ground surface. Temperature data from two wells in the Haines Junction area suggests the temperature gradient is ~60 °C/km. Thus, geothermal aquifers located near the top-of-bedrock in the four areas identified could have temperatures in the range of 39–74 °C. Production of geothermal fluids from these areas requires permeability in the sediments that sit above the bedrock. Deeper drilling is needed to measure actual subsurface temperatures beneath the village and to identify permeable intervals. Geologic structures and faults that may control permeability in the bedrock remain poorly constrained.