Geography Reference
In-Depth Information
The massive weight of glaciers is capable of grinding up even the hardest rocks into soil particles.
Sinceglaciersmove,theyareacombinationearthcrusher-bulldozerthatperformweathering,erosion,
and deposition all in one. The precise nature and results of these activities depends on whether the ice
in question is a mountain glacier or a continental glacier.
Mountain glaciers
Asthe name suggests, mountain (or alpine ) glaciers originate in snowthat falls in mountainous areas.
When large ice masses form, the slopes facilitate their downhill movement, and thus their power to
erode and transform the landscape. Far up-slope, the erosional power of so much ice “gnaws away”
at the mountain, turning rounded tops into pointed horns and nondescript ridges into jagged crests
called arêtes .
Applied Geography: Insuring against erosion
People who buy land and build on it generally expect their property to be there tomorrow.
But just in case, they buy insurance. Some policies that cover coastal real estate are is-
sued by private companies and others by branches of government. Either way, and rather
often, erosion takes its toll, so policy owners end up cashing in.
If you are thinking, “I don't own coastal property, so this doesn't concern me,” then I beg
to differ. Every successful insurance claim drives up policy costs, so, in that sense, every-
body pays to compensate people for eroded coastal property. In recent years, however,
many have begun to question the wisdom of such insurance. Key to this is growing public
awareness of basic physical geography, particularly erosion as it relates to beaches. In
some states and regions, the results have been moratoriums (or talk of them) on beach-
front housing, or on insurance policies that protect them. In so doing, the general public
and their elected representatives have been applying a basic concept that geographers
have appreciated for some time, namely, that the works of humans ultimately stand little
chance of permanency in that most dynamic of natural environments, the coast.
Main valley floors are widened and deepened, changing from V-shaped valleys into larger U-
shaped glacial troughs. Higher up, side valleys are also carved out. Less ice flows through
them than the main valley, so less down-cutting occurs. Once the glaciers recede, the former
side valleys are left “hanging above” the main valley, and are thus referred to as hanging val-
leys. In the mountainous coastlands of Norway, New Zealand, Chile, Western Canada, and
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