Permafrost and the shallow thermal regime at Alert, N.W.T.

• Main Authors: Taylor, A., Brown, R. J. E., Pilon, J., Judge, A. S.
• Format: Article in Journal/Newspaper
• Language: English
• Published: 1982
• Subjects: permafrost; pergélisol; soils; sol (terre); seasons; saison; temperature; température; cold regions; zone froide; Northwest Territories; Canada; terrain analysis; ground temperatures
• Online Access: https://nrc-publications.canada.ca/eng/view/ft/?id=06c0c1c7-ceb7-485a-8c84-466b1b700e54; https://nrc-publications.canada.ca/eng/view/object/?id=06c0c1c7-ceb7-485a-8c84-466b1b700e54; https://nrc-publications.canada.ca/fra/voir/objet/?id=06c0c1c7-ceb7-485a-8c84-466b1b700e54

In 1978, a shallow permafrost and terrain analysis study was started at Canadian Forces Station Alert, N.W.T. (82 degrees 30 minutes N, 62 degrees 26 minutes W). Five holes, drilled to depths down to 60 m, were instrumented with multi- thermistor cables, and temperature measurements have been taken every two or three weeks for the last three years by DND personnel. The drilling sites were chosen to cover various terrain types accessible from the Alert station. Preliminary air photo analysis indicates that the principal landforms are of glacial and marine origin. A 60 m temperature cable (site 1), installed within 100 m of a shore-line emerging due to glacial unloading, yields temperatures 4 to 5 K warmer than two similar cables installed on inland plateau sites (sites 2 and 3). An analysis of these three sites suggests the higher subsurface temperatures at the shore site result as much from its proximity to the sea as from the period of submergence prior to 3000 years ago. Temperature cables installed in two 15 m holes (sites 4 and 5) on gentle north- and south-facing slopes have shown that aspect has little influence on temperatures at this extreme latitude. Un projet pour étudier les caractéristiques du pergélisol en surface et la géomorphologie des environs de la station des forces armées canadienne Alert, T.N.-O. (82 degrés 30 minutes N, 62 degrés 26 minutes W) a débuté en 1978 par le forage de 5 trous dont certains ont une profondeur de 60 m. Le personnel du ministère de la Défense a, par la suite, effectué des relevés des profils de température à un intervalle de 2 à 3 semaines à l'aide des cables à thermistors multiples installés lors du forage. Les divers types de terrain disponibles à partir de la station d'Alert ont été le facteur prédominant dans le choix de l'emplacement des sites. Les dépôts surficiels de la région sont surtout d'origine glacière et marine. Un cable de 60 m (site 1) installé à moins de 100 m du rivage en voie d'émergence suite à la déglaciation, montre des températures de 4 à 5 K ...