Looming over Alaska's most economically important highway
Abstract: This project is the first part of a multi-phase approach to measure the deformation of an engineered structure when impacted by a landslide. Frozen Debris Lobe A (FDL-A) is a slow-moving landslide in permafrost that will collide with the current alignment of the Dalton Highway, Alaska, by 2023. The overall outcome for all phases of this research will be protocol on how to plan for movement of these features to ensure long-term mobility along the highway.
Abstract: Frozen debris lobes (FDLs) are slow-moving landslides along permafrost-affected slopes. Within the Dalton Highway corridor in the southern Brooks Range, Alaska, the project identified 43 FDLs, with 23 occurring less than one mile uphill of the Dalton Highway. The closest FDL to the highway, FDL-A, was just over 136 ft away from the embankment when measured in August 2014. Should the rate of FDL-A increase to match those measured on other, faster-moving FDLs, it could cover the distance to the highway in about a year. When it does reach the highway, the project estimates it will place 60 tons of debris on the highway each day. This research project will employ remotely sensed data using multiple data acquisition methods to monitor and analyze FDLs at different temporal scales, thereby increasing the understanding of rates and episodes of movement of these potential geohazards. The project will evaluate each technique for its overall cost, ease of use, and applicability to assessing the flow dynamics of FDLs. The results produced from this study are critical for stakeholders to make informed future decisions regarding the infrastructure and mitigation strategies.