The Pacific War Online Encyclopedia
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Permafrost is a feature of the frigid terrain close to the Earth's poles. It is a permanent layer of underground ice that is not thawed by the brief polar summer, due to the insulating effect of the overlying soil.
Early construction along the Alaska-Canada Highway
exposed long sections of permafrost, which melted during the Arctic
summer and ruined the roadbed. Road engineers responded by developing
roadbuilding techniques that kept the permafrost frozen, such as the
use of a thick gravel roadbed that mimicked the natural insulation
provided by overlying soil.
References
The Pacific War Online Encyclopedia © 2007 by Kent G. Budge. Index
