Geography Reference
In-Depth Information
Keeping permafrost frozen
A peculiar environmental phenomenon that has a powerful and direct bearing on debate
between drilling for natural resources and providing for wildlife is
permafrost,
permanently
frozen soil that underlies the tundra. If you drill for oil in the tundra and send it through a
pipeline to wherever, then the oil needs to be warm. That is because crude oil, which is
thick and viscous, flows very haltingly through cold pipe. And cold pipe is something that
Alaska's climate virtually guarantees for most of the year. Fortunately, crude oil is hot as
it comes out of the ground, and the warmth helps make it less viscous as it flows through
the pipe. But the warm oil warms the pipe, which can melt the permafrost underneath,
causing the pipe to sink into the ground and break, resulting in oil spills. For that reason,
and at great expense, the Trans-Alaska Pipeline is elevated on stanchions for much of its
route. This and other permafrost-related problems are at the heart of debate concerning
possible future oil exploration and drilling in the tundra.
Ice caps: Hollywood-style
Virtually every movie you have ever seen about the Arctic or Antarctic contains the ob-
ligatory blizzard scene in which the attendant “white out” easily lends the impression of
copious snowfall. Indeed, big snowfalls may occasionally happen, but ice cap blizzards
more typically result from high winds kicking up loose snow that never melted and has
yet to become consolidated with the ice cap.
Ice cap
In areas of ice cap climate, every month averages below freezing. As the name suggests, its distribu-
tion generally coincides with the ice caps that overlie Greenland and Antarctica. At low temperature
air can contain very little water. Also, due to the cold temperatures, relatively little evaporation takes
place in the polar realm. On both accounts, therefore, the air has a rather low supply of vapor, which
in turn depresses the possibility of precipitation. Thus, ice cap climate technically qualifies as desert
because it receives less than 10 inches of precipitation per year. The astonishing and uniquely low
temperatures, however, result in its being granted its separate climatic status.
As noted in Chapter 8, the ice caps in Greenland and Antarctica are a couple of miles thick, and all of
it is the result of precipitation, which would seem to contradict what I just wrote. But all of that ice,
however, is the product of thousands of years' worth of small annual accumulations of snow, which,
due to the year-round cold temperatures, tend not to melt, but instead accumulate, compact, and add
to the ice cap.
