pacific nw transportation consortium region 10 Pactrans

Degrading Warm Permafrost Impact on Transportation Infrastructure in Arctic Regions

PI: Joey Yang (UAA), zyang2@alaska.edu, ORCID:

Co PIs: Utpal Dutta (UAA)

AMOUNT & MATCH: $40,000 federal from PacTrans; $40,000 federal Match

PERFORMANCE PERIOD: 8/16/2023 – 8/15/2025

STATUS: Active

CATEGORIES: Climate Change, Transportation, Mobility

UTC PROJECT DOCUMENTATION:

FINAL PROJECT REPORT: will be available once completed

PROJECT DATA: will be available once completed

DESCRIPTION:  The ravage of climate change has created widespread effects on the permafrost environment and the built transportation infrastructure in many high-latitude communities in Alaska. The forecast is that the permafrost will thaw extensively in the decades ahead due to climate warming at a rate much faster than anticipated, and the associated ground settlement is causing substantial damage to the transportation infrastructure. By 2030, permafrost degradation is expected to raise the costs of maintaining public infrastructure by U.S. $3.6 billion to $6.1 billion.

Nome, a subarctic city in western Alaska, is underlain by 15-50 m thick permafrost, which has been warming and degrading under climate change in the last several decades. The thawing of warm permafrost and the subsequent ground settlement cause never-ending issues to the roads and bridges. In addition, being in a moderately seismic zone, the degrading warm permafrost can potentially amplify the ground shaking during seismic wave propagation through the uppermost recently thawed and unconsolidated soil layer, inflicting severe damage to the transportation infrastructure. These issues require a fundamental rethinking of the fate of various infrastructural facilities like transportation in the area. However, little effort has been devoted to such important and unique Arctic transportation engineering issues. This proposed project aims to fill such a knowledge gap in permafrost thaw settlement and seismic site response. Multi-method geophysical (electrical resistivity, seismic) and geotechnical investigations will be conducted at selected strategic sites in the Nome area to map the subsurface soil conditions to understand the settlement and dynamic properties of degrading permafrost so that remedial measures could be proposed for applications in the built transportation infrastructure. Additionally, the impact of future climate change on the infrastructure will be assessed by thermal modeling using downscaled climate predictions from CMIP6 for this area. The results will help assess the impact of degrading permafrost on and improve the resilience of Arctic transportation infrastructure considering climate change.