# Magnetic North



## Rosemary (Dec 10, 2005)

*A New Pole Position for Magnetic North*

“The magnetic north pole is drifting from North America at such a speed it could end up in Siberia in the next 50 years, say scientists.
Despite accelerated movement over the past century, the possibility that the Earth’s fading magnetic field will collapse or that the magnetic poles will flip is remote.
Scientists have long known that magnetic poles migrate and in rare cases swap places.  But exactly why this happens is still a mystery.
This may be part of a normal oscillation and it will eventually migrate back towards Canada.
Previous studies showed that the strength of the Earth’s protective magnetic shield has decreased 10 per cent in the past 150 years.
In the same period, the magnetic north pole wandered about 1100km out into the Arctic.
At the present rate, the magnetic pole could swing out of northern Canada into Siberia.  If that happens, Alaska could lose its Northern Lights.
The magnetic north pole was discovered in 1831 and when it was revisited in 1904, explorers found it had moved 50km.
Pole reversals are uncommon, happening at intervals of several hundred thousand years.
The last time the poles flip-flopped was about 780,000 years ago”.


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## Arkangel (Dec 10, 2005)

Does that mean we are for a pole shift soon. Last month on Discovery i saw about this shifting poles, they said it could happen anytime and when it does it is going to be really erratic.

Anybody else knows anything more?


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## chrispenycate (Dec 11, 2005)

Since nobody has a consistent theory of how the earth's magnetic field can invert, predicting when it might happen or how long it might take, and even if there is likely to be a blank period during the inversion (if I've correctly understood the lava flow evidence indicates that the changeover takes less than ten years- but overnight or taking  several years, while negligible difference on a geological timescale could be quite important to humans.
After all, the majority of charged particles  fron the sun(solar wind) are trapped in the Van Allen belts, generated by the earth's magnetic fields. In the case of the field collapsing, a large quantity if ionising radiation would reach the surface of the planet, probably eclipsing the ozone hole problem. The atmosphere would block a lot- but in the process, the atmosphere itself would aquire more radioactive components. Since nothing I've ever seen associates magnetic polarity reversals with extinction events, I assume that this bombardment is survivable- still, multiplying cancers by ten, or reducing grain yield by half , or even doubling the mutation rate of some microorganisms, while not species threatening, cold be considered inconvenient- and we can't even blame it on pollution or the Americans.
It is generally held that a planets magnetic field is related to its rotation- so how can it invert without spinning the planet in the opposite sense? Yet apparently it does. Oh, wobbling a bit- you can explain it wandering around.  But total inversion? Ridiculous. Yet our best evidence says it's happened several times in the past- so it could happen again in the future, with unpredictable results.


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## Rosemary (Dec 11, 2005)

more radioactive components?  Surviving the bombardment possible?  

Oh dear, I wish I hadn't started the thread now!!

Thank you Chris!!!


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## chrispenycate (Dec 11, 2005)

Rosemary said:
			
		

> more radioactive components?  Surviving the bombardment possible?
> 
> Oh dear, I wish I hadn't started the thread now!!
> 
> Thank you Chris!!!


You're very welcome.

"Despite accelerated movement over the past century, the possibility that the Earth’s fading magnetic field will collapse or that the magnetic poles will flip is remote."

Don't  worry about it- there's nothing anyone can do about it (except work in a recording studio like me) and the probability that it will happen in any particular thousand year period is acceptably low. I don't know about you, but I'm not intending to live into the next thousand year period, and can think of lots of higher probability catastrophies to if you need something to explain away your sleepless nights.


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## Rosemary (Dec 11, 2005)

Well, that is so reassuring to know!!  

No, I am like you, I do not want to live for that long, the music isn't getting anybetter these days for a start. So now all I do to be completely safe is to stay indoors, that way I won't get a satellite falling on my head or get sucked up into that vortex thingy again!!


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## dreamwalker (Dec 14, 2005)

the sun has the strongest and largest magnetic feild in the solar system, its poles flip every 12 years, the magnetic feild is also responsible for the solar maxium to minium shifts what correspond with the magnetic feild switch.

The super dence metallic hydrogen and helium are thought to be responsible for generating the sun's magnetic feild which gets warped and twisted by the suns rotation (the sun spins, with the central regions rotating faster than the poles.) The increased entropy within magnetic feild of the sun enduces more solar activity (eg flares and solar mass ejections).

So what does this mean for the earth?
The earth's magetism works very differently to sun, partly because the earth gets its feild through Iron and ferromagnetism. Unlike the sun, we have a solid and static crust with a molten metalic dense core and to work out what is happening to our planets magentic feild, knowing the relationship between the crust, mantle, and cores which are all constantly in flux and move in different cycles.


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