Vulnerability of the north Alaska Highway to permafrost thaw: Design options and climate change adaptation

The Alaska Highway between Burwash Landing and the Yukon/Alaska border is underlain by extensive discontinuous, warm and frequently ice-rich permafrost. The disturbance caused by construction of the road and climate warming has already led to the thawing of permafrost, which has had an impact on the road. Some sections of the highway have experienced longitudinal cracking, embankment failure, differential settlement and even complete collapse. In order to better understand these issues, the Yukon Government Department of Highways and Public Works (HPW) has partnered with the Northern Climate ExChange in a four-year project (2012-2016) to assess permafrost sensitivity to thaw under the northern 200 km of the Alaska Highway. Since its construction, this section of highway has been affected by permafrost thaw. In the context of current and anticipated climate change, permafrost temperature is warming and is expected to continue to rise (SNAP 2014). Faster and more extensive permafrost thaw will result in an increase of frequency and magnitude of the damage sustained by the highway.