Fire and Ice—The Effect of Wildfire on an Ice-Rich Slope along the Trans-Alaska Pipeline System

The quantity and intensity of wildfires have increased while permafrost in the interior of Alaska has become more vulnerable to thaw with warming climate conditions. The Trans-Alaska Pipeline System (TAPS) transports oil through a 1.2-m-diameter pipeline from Prudhoe Bay to Valdez and passes over stretches of warm, discontinuous permafrost. The pipeline is typically supported aboveground where it traverses thaw-unstable permafrost. In 2015, a lightning strike caused a wildfire in boreal forest underlain by ice-rich permafrost, northwest of Fairbanks, Alaska. Nearly 13 km of the pipeline were within or along the edge of the wildfire perimeter. Alyeska Pipeline Service Company selected a site to evaluate wildfire impact on warm, ice-rich permafrost, and long-term effects on aboveground pipeline supports. Findings show warming and degrading permafrost in the vicinity of the pipeline following the fire, indicating that wildfire control practices near TAPS could be re-evaluated where TAPS traverses warm permafrost.