Geologic History and Deformation Monitoring of the Sunnydale Landslide ...

• Main Author: Bodtker, Jackson William
• Format: Article in Journal/Newspaper
• Language: English
• Published: Arts 2024
• Subjects: Geohazards; Geomorphology; Landslide; Geology; FOS: Earth and related environmental sciences; Dawson City; Yukon; Dawson; Yukon river
• Online Access: https://dx.doi.org/10.11575/prism/42965; https://prism.ucalgary.ca/handle/1880/118121

The Sunnydale Landslide is a slow-moving rock-slope deformation on the western bank of the Yukon River directly across from Dawson City, Yukon. Field mapping documented road subsidence, expanding tension cracks, recent and ongoing rockfall and shallow landslide activity, and production of detailed geomorphological and surficial geology maps of the landslide. Results from geologic dating of the slide show that is has been a feature of the landscape since at least 10,000 years before present. Due to this age, present rates of surface displacement across the slide are incompatible with observed total deformation, implying either episodic movement or recent acceleration. Results from photograph interpretation and dendrogeomorphological study show deformation throughout much of the 20th century. Additionally, lidar and GNSS/GPS monitoring from 2014 to 2023 show over 20 cm of 3D displacement annually in parts of the landslide. Recent lidar differencing and GNSS data suggests possible acceleration of the landslide, ...