Climatic and geomorphic factors affecting contemporary (1950-2004) activity of retrogressive thaw slumps on the Aklavik Plateau, Richardson Mountains, NWT, Canada

The climatic and geomorphic factors affecting retrogressive thaw slump initiation and activity on the Aklavik Plateau (Richardson Mountains, NWT) were examined using historical air photographs over a 54-year period (1950 to 2004). In this region, thaw slumps include a near-vertical headwall, a floor of low gradient (2?10°) and a steeply sloping evacuation channel (15?25°) that connects the floor of the thaw slumps to Willow River located 60?150?m below. All thaw slumps on the Aklavik Plateau are located within the glacial limit of the Laurentide Ice Sheet and the majority developed on the western side of the valley on gently sloping terrain. Aerial photographic analysis showed an increase in thaw slump initiation from 0.35 new thaw [...]