25 years of movement monitoring on South Peak, Turtle Mountain: understanding the hazard

Abstract

In 1981, an Alberta Government project upgraded the monitoring of South Peak, Turtle Mountain, on the south margin of the 1903 Frank Slide. The monitoring program aimed at understanding the rates of deformation over large, deep fractures encompassing South Peak and predicting a second large rock avalanche on the mountain. The monitoring program consisted of a complement of static ground points and remotely monitored targets measured periodically, and climatic, microseismic, and deformation data collected automatically on daily intervals and archived. In the late 1980s, developmental funding for the monitoring program ceased and some of the installations fell into disrepair. Between May 2004 and September 2006, readings from the remaining functional monitoring points were compiled and interpreted. In addition, readings compiled previously were re-interpreted based on a more recent understanding of short-term movement patterns and climatic influences. These observations were compared with recent observations from an airborne light detection and ranging (LiDAR) digital elevation model and field photographs to give more precise estimates of the overall rates, extent, and patterns of motion for the past 25 years.