A comparison of permafrost landslides in previously glaciated and unglaciated terrain along the Dempster Highway; Eagle Plains, Yukon, and Peel Plateau and Interior Plain, Northwest Territories

Abstract

This thesis examines the areal distribution of retrogressive thaw slumps (RTS) and active layer detachment slides (ALDS) in three areas of the Dempster Highway adjacent to the Richardson Mountains, in Canada’s Northwest Territories and Yukon between 1949 and 2017. It also provides new data on the rate of growth, slope, elevation, and aspect over time. The study locations are within the following areas: the unglaciated Eagle Plains, west of the Richardson Mountains; the previously glaciated Peel Plateau, east of the Richardson Mountains; and the Interior Plateau, east of Fort McPherson. Interpretation of aerial photos and satellite images shows that unglaciated terrain within Eagle Plains had far fewer retrogressive thaw slumps per 100 km2, compared with the Peel Plateau. ALDS in both study areas showed a correlation with preferential drainage feature orientation and occurred primarily on steep valley sidewalls. No RTS or ALDS where identified in the Interior Plateau study area.