The increase in temperature caused soil displacement, which caused the pipeline supports to deform
The Trans-Alaska oil pipeline, one of the largest in the world, could be in danger.
Melting permafrost threatens to erode the pillars holding its above-ground portion, jeopardizing its structural integrity and increasing the risk of an oil spill.
The slope of permafrost, on which a section of the pipeline about 250 meters long is fixed, began to shift due to thawing, as a result of which several supports holding the pipes began to bend.
In response, the Alaska Department of Natural Resources approved the use of about 100 thermosyphons — tubes that take heat from permafrost to keep the frozen slope in place and prevent further damage to supporting structures.
“This is a wake-up call,” said Karl Weimer, a special projects advisor for the Pipeline Safety Trust, an NGO based in Bellingham, Washington. «This shows … the impact of climate change on the safety of pipelines in general.»
Permafrost is soil that remains completely frozen for at least two years in a row.
About 124 thousand thermosyphons have been installed along the pipeline, which speaks of the importance of keeping the soil underneath frozen. They are installed at a depth of 4 to 20 meters in areas of permafrost where warming can cause it to melt.