Is The Reversal of the Poles Such a Big Deal?

[jimmydasaint]

It seems that the Earth may experience a reversal in the Geomagnetic Poles so that the Magnetic North and Magnetic South get reversed. Now, I can see this being a problem for migrating birds and marine animals that may use fields to navigate. However, it is not likely to affect humans to a significant extent, for example to cause large numbers of casualties...

or is it? Any thoughts?

 

 

Although the inspection of past reversals does not indicate biological extinctions, present society with its reliance on electricity and electromagnetic effects (e.g. radio, satellite communications) may be vulnerable to technological disruptions in the event of a full field reversal.

 

http://en.wikipedia.org/wiki/Geomagnetic_reversal

 

from:

http://www.mnh.si.edu/earth/text/4_1_5_0.html

[Edtharan]

Well the magnetic field actually protects us from high energy charged particles emitted by the sun. When these charged particles encounter a magnetic field they are deflected. If these weren't deflected, they would rain down on us and damage our cells and DNA.

 

As the change of the poles would not happen instantly (maybe over decades or centuries), then we would be exposed to these highly damaging particles for that length of time. Rates of cancers would sky-rocket, and this would be bad for humanity (not to mention virtually all other forms of life too).

[gonelli]

As Edtharan mentioned, many forms of life would suffer from exposure to high-energy radiation. Given the magnetic field would vanish for a while (as stated on mnh.si.edu), it is interesting that inspection of past events didn't show extinctions or a least serious drops in the population of various flora and fauna.

[jimmydasaint]

Well the magnetic field actually protects us from high energy charged particles emitted by the sun. When these charged particles encounter a magnetic field they are deflected. If these weren't deflected, they would rain down on us and damage our cells and DNA.

 

As the change of the poles would not happen instantly (maybe over decades or centuries), then we would be exposed to these highly damaging particles for that length of time. Rates of cancers would sky-rocket, and this would be bad for humanity (not to mention virtually all other forms of life too).

 

This is a BIG deal and a frightening thought. Bearing in mind that the ozone layer is relatively depleted, do you think that the effect of these charged particles will be increased? Just cross-contextualising but is it possible that such an event occurred when dinosaurs became extinct and the dino's died of massive cancers?

[Pangloss]

If memory serves, pole reversal is also thought to be a possible (if unlikely?) precursor to an overall reduction in the strength of the field, which of course would lead to the eventual loss of atmosphere (ala Mars). I think that theory is pretty unsupported at present, though. I remember seeing a Nova on it, but then we talked about it here and people said it wasn't very likely.

[booker]

Does mitochondrial DNA display mutation rates consistent with flux reversal frequency?

[iNow]

I remember seeing a Nova on it, but then we talked about it here and people said it wasn't very likely.

It was a good special. I saw it, too... several years ago:

 

http://www.pbs.org/wgbh/nova/magnetic/

[CaptainPanic]

One effect: every old fashioned TV set (not the flatscreen ones) will stop working properly.

[JohnB]

Pangloss, I don't see the connection. The atmosphere is held by gravity, not a magnetic field. AFAICT a plenet with sufficient gravity will have an atmosphere regardless of whether or not it generates a magnetic field.

 

I'm with gonelli on this one. The geological record shows no connection between pole reversal and extinctions or large reductions in life on Earth. Since there is no evidence for large scale adverse effects in the past there is no reason to assume them for the next one.

[D H]

Pangloss, I don't see the connection. The atmosphere is held by gravity, not a magnetic field. AFAICT a plenet with sufficient gravity will have an atmosphere regardless of whether or not it generates a magnetic field.

Mars is believed to have lost its atmosphere as a result of losing its magnetic field, which on Mars occurred because its plate tectonics shut down. Without a magnetic field to deflect the solar wind around the planet (and away from the atmosphere), the solar wind over time stripped Mars of its atmosphere.

 

Some references:

http://science.nasa.gov/headlines/y2001/ast31jan_1.htm

http://adsabs.harvard.edu/abs/1993emhw.work...14J

 

Regarding the Earth's geomagnetic reversals: First and foremost, these reversals occur over a fairly short time span compared to the amount of time needed for the solar wind to strip the Earth of its atmosphere. We will not lose our atmosphere as that would require the complete loss of our magnetic field over a geological time span.

 

The Earth's magnetic field will not completely vanish during a geomagnetic reversal. Only the dipole moment will vanish; there will still be some remnant field in the higher order moments that will offer some protection against cosmic radiation. We might experience higher cancer rates and wacky weather for a decade or two, and it almost certainly would wreak havoc with our power transmission and data communications systems. Only the wackos say it is the end of the Earth (and in 2012, no less). Life has survived many such reversals. There are no signs of even minor extinctions event correlated with such reversals.

[CaptainPanic]

I can see that solar winds (very high speed particles) can strip a planet of its atmosphere. I think it'll be a slow process, but one by one atmospheric molecules are hit by high speed particles and thus accelerated. Some might escape earth. If this happens enough, then the atmosphere will be gone after sufficient time.

 

Can anyone comment: is this process more likely to occur at the geographical poles of a planet (regardless of the magnetic field), because the solar winds are almost parallel to the surface?

 

What is keeping the molecules / ions in our atmosphere? The magnetic field is vertical at the poles, and horizontal elsewhere (ok, I like to simplify things) and the upper atmosphere is essentially a very thin plasma with both positive and negative particles. The solar winds are the same: thin plasma's.

 

I understood that solar winds are reflected. But the ionosphere is not reflected... and this all got me quite confused

[JohnB]

Thanks DH, I get it now.

[bombus]

 

As the change of the poles would not happen instantly (maybe over decades or centuries), then we would be exposed to these highly damaging particles for that length of time.

 

Mmm. Are you sure about that? I thought that the magnetic field is due to the spinning of the Earth's core, and that when the poles reverse it really is pretty much instant...

 

Correct me if I'm wrong.

 

Also, birds would not be that affected if the flip is quick as they do not necessarily know North Pole from South Pole, but just use the general direction of the polarity to help guide themselves around - as they use stars and landscape features too.

[Edtharan]

I thought that the magnetic field is due to the spinning of the Earth's core, and that when the poles reverse it really is pretty much instant...

 

Correct me if I'm wrong.

The Earth's core is very massive. It would take a massive amount of energy to stop it virtually instantly and then start it up again just as quickly (Force = Mass * Acceleration or Force = Mass * (Distance / Time) ).

[Kyrisch]

Mmm. Are you sure about that? I thought that the magnetic field is due to the spinning of the Earth's core, and that when the poles reverse it really is pretty much instant...

 

Correct me if I'm wrong.

 

Also, birds would not be that affected if the flip is quick as they do not necessarily know North Pole from South Pole, but just use the general direction of the polarity to help guide themselves around - as they use stars and landscape features too.

 

"The Core" is nowhere near a scientific movie xP. Is that what you're referencing?

[Gertwor]

Yeah I definitely agree to that "the Core" is not an scientific movie (And a very idiotic one too) but I do think that massive magma floating can cause magnetic field as such those are heavy metals with large charges so it will most certainly one of the reasons for our magnetic filed by the way What really produces our magnetic filed and where is it's electro-magnetic field ?

[CaptainPanic]

The reversal of the poles would turn around the statistical average orientation of cows. They point north now.

 

http://www.telegraph.co.uk/news/newstopics/howaboutthat/2623809/Cows-point-north-thanks-to-in-built-compasses.html

 

Probably not very important, but funny enough to spam the forum with.

 

[edit] ... And then I spotted the other thread.

Edited August 27, 2008 by CaptainPanic
other thread was first with this "news".

[Edtharan]

but I do think that massive magma floating can cause magnetic field as such those are heavy metals with large charges so it will most certainly one of the reasons for our magnetic filed by the way What really produces our magnetic filed and where is it's electro-magnetic field ?

The Core of the Earth is not magma, but instead made up of a solid iron inner core and a liquid iron outer core.

 

Any conducting fluid that is rotating can develop a magneto effect.

 

As liquid iron is conductive, and the Earth is rotating, this will create a magneto effect.

[bombus]

The Earth's core is very massive. It would take a massive amount of energy to stop it virtually instantly and then start it up again just as quickly (Force = Mass * Acceleration or Force = Mass * (Distance / Time) ).

 

I don't think the core actually does stop spinning, it just flips in polarity.

[CaptainPanic]

I always thought that the process was a bit more gradual:

First some other regions on earth become a magnetic north or south (there will be more than 1 magnetic north pole)... This then finally results in flipping the magnetic field completely.

 

I saw this in a documentary. The theory was based on magnetic rocks that were found all over the place (and the direction of the magnetic field in these rocks). The rocks were dated and thus a magnetic history was obtained. What I do not recall is how many rocks, or how many data points, researchers have investigated. I'd say you need lots and lots of data points to make such a claim...