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Abstract:
The Geological Survey of Canada has maintained a network of permafrost thermal monitoring sites along the Norman Wells pipeline corridor between Norman Wells (NWT) and Zama, Alberta, since 1984. A total of 23 thermal fences or instrumented cross-sections have been established at which ground temperatures are measured both on and off the pipeline right-of-way (ROW). The design of the thermal fence allows an investigation of the effect of ROW clearing, pipeline trenching, installation and operation on the ground temperature and also to compare the thermal regime of the ROW and the surrounding terrain. Temperatures are measured to depths of 5 m close to the pipe and at a depth of 20 m between 4 and 10 m from the pipe and off-ROW. Initial manual data collection was at monthly to bi-monthly intervals decreasing to one to three times annually in later years. In the mid 1990s, a number of temperature cables were connected to dataloggers to provide high frequency measurements.