One of the world’s major oil pipelines, the Trans-Alaska Pipeline, could be jeopardized. Thawing permafrost threatens to destabilize the supports that hold up an elevated section of the pipeline, compromising its structural integrity and boosting the risk of an oil leak in a fragile and remote environment. In addition, as the permafrost thaws, the slope where an 810-foot stretch of the pipeline is held has begun to shift, twisting and bending some of the bracing holdings up the pipeline.
According to records and conversations with personnel associated with the pipeline’s management, this appears to be the first time pipeline supports have been damaged by “slope creep” caused by thawing permafrost. As a result, the Alaska Department of Natural Resources has approved the deployment of around 100 thermosyphons — tubes that extract heat from permafrost — to maintain the frozen slope in place and protect the pipeline’s support system.
Carl Weimer, the special project’s adviser for Pipeline Safety Trust, said, “This is a wake-up call. The implications of this speak to the pipeline’s integrity and the effect climate change is having on pipeline safety in general.”
While these tubes are commonly employed along the pipeline’s length, records reveal they have never been deployed as a protective measure once a slope has started to slip. Permafrost is ground that has been frozen for at least two years, and it covers almost 85 percent of Alaska. Temperatures in the permafrost there have risen as much as 3.5 degrees Fahrenheit in the last several decades.By the middle of the century, the state’s average temperature is expected to rise 2 to 4 degrees. According to a study published in the journal Nature Climate Change, for every 2 degrees of warming, 1.5 million square miles of permafrost might be lost to thawing.