Permafrost, the frozen ground that lies beneath the surface in most of the state of
The Thermosiphon, a tube filled with gas that cannot escape, is buried in the ground with the top exposed to the air. As the temperature plunges in winter the gas condenses into a liquid and falls to the bottom of the tube. When the weather warms up during the summer months, the warmth of the ground causes the liquid to evaporate back into a gas that rises to the top of the tube where the heat it carries is dissipated into the air the cycle keeps repeating itself, with no need for any kind of power source or any intervention other than maintenance. Scientists believe the process cools the ground around the tube so much during the winter that it stays frozen even in summer. Alaska Pipleline crews inspect the working of the thermosiphons using infrared cameras. If the telltale glow of heat being released is too dark, that indicates a gas blockage that may need repair. It appears
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