Plate Tectonics
Prior to World War II, humans were
conformed with the idea that the Earth and
its continents had been basically
unchanged since the beginning of time. A
German meteorologist, Alfred
Wegener observed that the coastlines of the seven
continents could be fitted
together almost perfectly like a jigsaw puzzle. If
fitted together, the
geological dating the land would match as well as other
geological features.
He believed that this was more than coincidence, which
happened to be the
belief at the time. By putting all the continents together,
he formed a large
landmass that he named Pangea. This would also explain the
same fossils found
on 2 continents, separated by large oceans. Although the
continents fit
together nicely, and it would solve many of the earth's
mysteries, people
still rejected the idea that the continents moved for several
reasons.
Ignorance and strong religious beliefs played a part in this, but it
was
mainly rejected because of the lack of a good explanation for the movement
of
the continents. Wegener's theory for the movement of continents was
called
continental drift. This was not believable at the time because there
was no way
the continents could move through the rigid ocean floor. During
WWII, people
started to explore the ocean floor and discovered evidence that
would prove
Wegener's ideas about land movement. The most interesting
feature of the ocean
was the ridges running along the ocean floor. It was
discovered that earthquakes
were abundant along the ridges that let magma
flow from them. The magma would
flow out these ridges and push the Earth away
from it. This sea floor spreading
was how the continents had moved over
millions of years. The earth's crust is in
mobile sections called plates,
moved by the circulation of magma in a layer of
the earth called the mantle.
The moving and colliding of plates form many of
today's landforms such as the
Himalayan Mountains. They were formed when India
moved into Asia, colliding
and making the shores of India go underneath Asia.
Although we have found
much on plate tectonics, there are still some unanswered
questions. The
depths of the plates are still unknown. Scientists are still
unsure on how
the motion of the mantle was initiated. There are many theories on
how plate
tectonics works and why the polarization of the Earth switches every
million
years but there have been no concrete facts. Plate tectonics needs to
be
explored more in order to solve much of the mysteries of the earth. It
has
already answered many questions about the geologic history. The moving
plates,
volcanoes, and faults explain much of the earth's topography. If we
come to a
better understanding of plate tectonics, the evolution of different
species of
animals will become clearer to us. The history of plate tectonics
will help us
understand the past migrations of species and even early humans.
Not only can
studying plate tectonics help in understanding the past but can
help predict the
future. Advancement of these theories may help predict
earthquakes in plenty of
time to spare millions of lives and can help us
predict the topography of
the
future.