Water Resources Research Act Program

Details for Project ID 2012AK109B

Rapid Moving Debris Lobes in the Brooks Range of Alaska

Institute: Alaska
Year Established: 2012 Start Date: 2012-03-01 End Date: 2013-02-28
Total Federal Funds: $18,441 Total Non-Federal Funds: $9,128

Principal Investigators: Ronald Daanen

Abstract: The project provides a continuation of a reconnaissance investigation of a potential hazard caused by an unusual form of mass movement on permafrost slopes in the southern Brooks Range, Alaska. To date there is no descriptive name for these features these are therefore described as frozen debris lobes. The reconnaissance study to date has focused on the characterization of frozen debris lobes and processes using ground-based surveys, remote sensing, field and laboratory measurements, and observations of frozen debris lobe systems along the Dalton Highway. Our results indicate that frozen debris lobes have responded to climate change by becoming increasingly active during the last 10 years, resulting in rapid downslope movement and manifested by toppling trees, tree ring variations, potential basal sliding, slumping, and surface cracks. Ground-based measurements over three years revealed average movement rates of approximately 1 cm/day, which is substantially larger than rates measured in historic aerial photography from the 1950s to 1980s. Observed movement and transport mechanisms of frozen debris lobes include creep, mudflows, detachment slides, and the leaching and redeposition of fines. Preliminary findings show that climate change may further influence frozen debris lobe dynamics, potentially accelerating their movement. These features can pose a real thread to the Dalton Highway and Trans Alaska Pipeline System, the main artery for transportation between Interior Alaska and the North Slope. In this project it is proposed to investigate the below ground characteristics of these features using seismic and DC-resistivity on one the most threatening features to understand the potential for below ground processes. Of particular interest is the existence of failure plains underneath the features that could lead to potential catastrophic movement of the frozen mass.