ACTIVE LAYER AND SUPRAPERMAFROST GROUNDWATER STUDIES, SCHEFFERVILLE, QUEBEC

Ground temperature observations indicate that active layer depth is usually related to surface cover. However, under drainage lines the active layer is usually much deeper or a talik zone may be present, and it is thought that this is due to the transport of heat by suprapermafrost groundwater. Ground temperatures, water table height and related data were collected over a summer in a small catchment containing a zone of deep thaw, with a view to producing subsurface heat and water budgets. The results indicate that heat conduction alone can account for the thermal flux on average sites but cannot account for the deep active layers; that much of the groundwater movement is through limited zones of high permeability; and that there is substantial suprapermafrost groundwater movement through the deep active layer and talik zones.