|What would happen if earth lost its magnetic field
and could it be caused by humans?|
|Question Date: 2015-02-26|
Hi, this is an interesting question. Given that
you asked this question, you probably already know
a little bit about the magnetic field but I
will still start at the beginning. When the Earth was formed and very hot, most of
the heavy elements sank down to the core of the
Earth and thus our planet has a heavy core made
mostly of Iron and Nickel. The outer part of
that core is liquid and is moving. The movement
of the liquid iron causes a magnetic field that is
similar to a typical magnet that you can buy at a
store just way way larger. Since the source of
the magnetic field is deep down in the earth, I
cannot think of any way how humans could stop it.
So the answer to your second question is:
No, humans could not cause the magnetic field
to stop. At least, I cannot imagine how. Could
the magnetic field stop in a natural way
though? The answer to that question would be:
Maybe - but it is very unlikely that this will
happen any time soon.
There is evidence that the magnetic field has
been around for nearly 3500 Million Years; that is
three fourths of the entire age of the Earth so it
is very unlikely that the magnetic field stops in
the near future. O.K. But even if it is unlikely,
what would happen if it (the magnetic field)
got lost? One important feature of the
magnetic field of the Earth is that it causes
certain particles and rays to move around the
Earth instead reaching the atmosphere. If the
magnetic field was weaker or not there at all, the
Earth would receive much more intense radiation
from the sun and this radiation would likely be
harmful to us humans and other lifeforms.
These “solar winds” could also affect our
atmosphere . Over time our atmosphere loses gases
to space. So in the past, there was a “thicker”
atmosphere and over time more and more gases got
lost and the atmosphere became thinner. Some
people think that this loss was very important in
forming the atmosphere as it is today. In the
future, the atmosphere will become even thinner
and thinner until eventually the oceans will
evaporate and life will become more and more
difficult. This process happens over VERY long
times (many millions of years). Now if the
magnetic field was lost and more “solar winds”
reached the atmosphere, the atmosphere could be
lost faster however, it would still take a
long time for all of it to be gone.
In summary, if the magnetic field weakened or
vanished, the Earth would be less protected
against harmful solar radiation and would also
likely lose its atmosphere faster than it does
It will not be a good thing for our planet. The
magnetic field helps shield us from things in
space (like rocks and solar energy) that come too
close. If it disappears it will make space
rocks more likely to collide with us, and harmful
radiation from the Sun will not be deflected away
and could actually strip the ozone layer away.
The ozone layer is what protects us from
harmful UV rays. So you can see that it is not
something we want to see. However, I personally
don't think you have to worry too much about it,
as the likelihood of that happening is quite slim.
Unfortunately, I don't know if humans can cause
the magnetic field to disappear. I want to say no,
but I'm not really sure. I hope another scientist
answers this part.
Just a side note, the thickness of the
magnetic field is not the same everywhere.
Some places have it thinner, others have it
thicker. I don't know if you've heard of them, but
the areas where the magnetic field is thinnest
(near the north and south poles) are places where
we see "auroras". These are spectacular
show of lights caused by solar radiation
interacting with our atmosphere because of thin
magnetic shield. If you don't know what they look
like I suggest asking your teacher to show some
pictures. They are really cool!
If earth lost its magnetic field, many means of
navigation would fail, including the ways in
which many birds and marine mammals locate where
they are and where they need to go, would fail.
Whether these animals could use other queues (such
as the sun's position in the sky) remains to be
seen. Many human navigation systems would also
fail (such as anything using a compass).
There is no reasonable way that humans could
alter the Earth's magnetic field. The Earth's
magnetic field is produced by the Earth's liquid
outer core, which is more than 3,000 km into the
Earth. We can't get down there to do anything.
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