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Author Topic: Why Does The Earths Poles Switch ?  (Read 2651 times)

Offline neilep

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Why Does The Earths Poles Switch ?
« on: 21/11/2007 14:11:03 »
Not too sure if this is the correct forum but I know there have been many discussions about the magnetic poles shifting or flipping...but has anyone actually said WHY does this happen ?

You speculations would be welcome.

Surely the molten core doesn't just stop spinning and then start spinning the other way ?.....or does that have nothing to do with pole reversal ?

Could it be something to do with the long many years cycles that the earth goes through, be it orbital around the sun or the way it wobbles ..or others ?

Is it because of an external force ?..Internal ?...volcanic activity ?  tectonic activity ?

Any ideas ?...whajafink ?

If this has in fact been answered recently then I apologise for bringing it up again



 

Offline syhprum

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Why Does The Earths Poles Switch ?
« Reply #1 on: 21/11/2007 17:06:39 »
Although there must be a great deal of energy stored in the rotation of a liquid core the time between reversals is quite long.
It seems to me that the speed of rotation of the core could vary from slightly more or slightly less that the rotational speed of the Earth as a whole.
This could be due to a temperature induced size change due to varying radioactivity caused by the convection currents in the overlaying mantle.
« Last Edit: 22/11/2007 15:25:58 by syhprum »
 

Offline Batroost

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Why Does The Earths Poles Switch ?
« Reply #2 on: 22/11/2007 19:56:02 »
If the earth's core is acting as self-exciting dynamo then (if I recall corectly) the magnetic field can be reversed without reversing the physical direction of rotation.
 

Offline syhprum

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Why Does The Earths Poles Switch ?
« Reply #3 on: 22/11/2007 20:45:15 »
I did not suggest anything as large as a reversal of direction rotation of the core only that the rate of rotation relative to that of the Earth might change.
It is well known that this happens in stars and gaseous planets where different layers rotate at different rates.
This is the explanation put forward for the 22 year sunspot cycle with the magnetic polarity of the sunspots changing over this period.
 

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Why Does The Earths Poles Switch ?
« Reply #3 on: 22/11/2007 20:45:15 »

 

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