When you wake up in the morning and drive by a lake,
do you just see a lake or do you see more? Well, every morning
when I go to school I guess I've never thought of the lake more than
just a body of water. Lakes age as we do and has a life span just as
we have.
The lakes that we fish, swim, ski, and boat in every
day have a long history starting with the first ice ages. Some
scientists believe ice ages were brought on by the solar dust 2.3 billion
years ago. What happened, possibly, was a supernova exploded
and made solar clouds that cut off all sunlight to earth and made it
cool rapidly. The scientists believe this could have happened over a
time period of several millions of years.
The major ice sheet that made our lakes, hills and
everything we walk was the Laurentide, which covered about five
million square miles of the US and Canada.
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This happened
around 14,000 years ago. The reason that this affected us so much is that
the temperature rose and fell, which sent armies of smaller
glacieral deposits streaming out to the oceans making many lakes
and hills by stripping off the top layer of land. This was the major
ice sheet that formed our land.
The second ice sheet that helped form our land was the
Cordilleran ice sheet. This sheet originated in Canada and parts
of Alaska. This formed the features in most of our Midwest and a
lot of the western US. States like Wyoming, California, and
Colorado. |
One of the other forces that helped shape our lakes
today was a major warming period about 14,000 to 7,000 years ago.
During this time the earth warmed abruptly melting the ice and
shaping the land. After all this warming, there was a gradual drop
in the temperatures that brought back a lot of the glaciers. This
theory was formulated by two geologists named Willi Dansgaard and
Hans Oeschger, thus the title the Dansgaard-Oeschger period.
In conclusion, our lakes are where they are because of
the ice sheets and warming periods we had. Our lakes are part of our
history and very important. So when you go to work in the morning
and pass a lake you should see more than just a body water that is there. |