Thermal Regime of Two Talus Slopes in Northwestern Ontario

This thesis investigates the thermal regimes of two talus slopes near lakes Superior and Nipigon, Ontario. Mean annual air temperatures in the region are periglacial, but little work has been done on whether permafrost or anomalously cold ground exist in blocky materials in the area. Air and internal talus temperatures were recorded, and the dimensions of the rocks and the temperature at the base of the snow were measured. Internal talus temperatures increased with elevation. The talus slopes at both Doghead Mountain and Ouimet Canyon experienced an unstable thermal regime with significant convection during the winter, and a stable, stratified thermal regime with significant conduction during the summer. The summertime thermal regimes of the lower sections of the slopes were dominated by zero curtains. Thaw completion depended on the length of the zero curtain, and thus on the amount of ice in the talus. Permafrost was found in Ouimet Canyon.