S18: The Alaska Pipeline's Permafrost Challenge
Video duration: 0:37
The oilmen planned to build the Alaska pipeline the same way they'd built every other pipeline in the world -- dig a ditch and bury it. This would not work in the arctic. Beneath a thin, insulating cover of tundra and vegetation, much of Alaska sits on permanently frozen ground called permafrost. In some places, it's mostly gravel, but in others it's mostly ice.