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View Full Version : What WILL happen when the poles shift?



parallaxicality
2004-Dec-01, 12:09 PM
I hesitated posting this on General Astronomy, but really, it is a legitimate astronomical question. Earth's poles have shifted in the past, they will shift again. That, it appears, is fact. Do we know what will happen? Do we have an idea why? Can we make any predictions based on what we know about the nature of the Earth, its magnetic field, and its biosphere?

Bozola
2004-Dec-01, 12:47 PM
Geologic of magnetic?

frogesque
2004-Dec-01, 12:48 PM
With GPS I don't think navigation will be a problem and apart from aurora turning up in unusual locations I don't think we will notice a lot of difference. The Earth's magnetic field will still offer protection from solar rays during a reversal and there won't be any mass extinctions. There is a lot of literature out there (good and bad) but some sites might be of interest

Computer generated model (http://www.psc.edu/science/glatzmaier.html)

Space.com Hubble article (http://www.space.com/scienceastronomy/generalscience/earth_poles_991027.html)

British Geological Survey (http://www.geomag.bgs.ac.uk/reversals.html)

kucharek
2004-Dec-01, 12:52 PM
I've never heard that there was a relation between changes in the magnetic field of the earth and the development of the biosphere. So, except for that your compass would mislead you, I wouldn't worry too much.

And, hey, we all know from Star Trek that reversing the polarity is always a good thing! :-)

Harald

Evan
2004-Dec-01, 04:47 PM
Not so fast. It is possible that a field reversal occurs by the field collapsing and then rebuilding. If that happens we have a serious problem without the magnetosphere to protect earth. Solar radiation levels at ground will increase greatly and we may experience a world wide ozone hole which will increase UV insolation. Even if the field simply topples without losing strength the polar ozone holes will follow. Place an ozone hole over the equator and it will be unliveable.

N C More
2004-Dec-01, 06:14 PM
With GPS I don't think navigation will be a problem and apart from aurora turning up in unusual locations I don't think we will notice a lot of difference. The Earth's magnetic field will still offer protection from solar rays during a reversal and there won't be any mass extinctions. There is a lot of literature out there (good and bad) but some sites might be of interest

Computer generated model (http://www.psc.edu/science/glatzmaier.html)

Space.com Hubble article (http://www.space.com/scienceastronomy/generalscience/earth_poles_991027.html)

British Geological Survey (http://www.geomag.bgs.ac.uk/reversals.html)

Great sites! Unfortunately there are many other websites that feature the doom and gloom, end of the world scenario as coming with the pole shift. There seems to be a lot of "woo woo" thinking in regard to the pole shift. My personal favorite site typifying this genre being The Grant Chronicles (http://www.grantchronicles.com/poleshift.htm) examination of the pole shift. When you see sites such as this please disregard them.

Damburger
2004-Dec-01, 06:25 PM
All the maps in the world will have to be reprinted, because they will be the wrong way up :)

Jobe
2004-Dec-02, 02:44 AM
going completely from memory here, but doesn't it take like hundreds/thousands/tens thousands of years for the pole to actually reverse? Its like a slow gradual process I believe. Most people make it sound like 'omg north is now south and it happened while i wasn't looking"

tuffel999
2004-Dec-02, 02:47 AM
Not so fast. It is possible that a field reversal occurs by the field collapsing and then rebuilding. If that happens we have a serious problem without the magnetosphere to protect earth. Solar radiation levels at ground will increase greatly and we may experience a world wide ozone hole which will increase UV insolation. Even if the field simply topples without losing strength the polar ozone holes will follow. Place an ozone hole over the equator and it will be unliveable.

What? You want to try that again?

There is a website attached to his board...and a search feature.

Wolverine
2004-Dec-02, 03:50 AM
I enjoyed the articles here (http://www.nasa.gov/vision/earth/lookingatearth/29dec_magneticfield.html) and here (http://www.space.com/scienceastronomy/earth_poles_040407.html) on the subject. The first offers a little nicer detail while exploring the same modeling done by Glatzmaier in frogesque's first article -- unfortunately, on that source they link out to that (rather sad) NYT article from earlier this year at the bottom of that page, which was discussed here (http://www.badastronomy.com/phpBB/viewtopic.php?p=297296).

Evan
2004-Dec-02, 05:14 AM
Nobody understands how the shift occurs. Perhaps, Clement says, the magnetic field shrinks to essentially nothing, leaving several "mini-poles" at the surface before the main poles rebuild on opposite sides of the world.

Scientists have plenty of reasons to seek a better understanding. For one, the magnetic field lines extend out beyond Earth's atmosphere and provide the first line of defense against strong solar storms. And Clement wonders how the reversals might affect navigation by migrating birds and other animals that key in on the magnetic field to find their way.

My emphasis, from the link posted above.

A severely weakened geomagnetic field is not going to fry life on Earth but it does increase the ground level radiation. This may well be sufficient to boost the mutation rates of species. Look up "ground level event". Then think of it continuing for 1000's of years.

Gullible Jones
2004-Dec-02, 05:17 AM
Magnetic compasses will be screwed up for a while. Life as usual will continue. And no, we won't die from cancer, because a nice thick atmosphere makes good radiation shielding.

Fram
2004-Dec-02, 09:42 AM
The pigeons might have problems though.

Nicolas
2004-Dec-02, 10:05 AM
Current measurement data suggests we are going towards a pole shift indeed. Examining stones reveals that the earth is "overtime" (relative to the average interreversal time, which isn't constant at all, so this doesn't mean a lot) already. But nobody can predict when it will happen. It can be within 10,100,1000,100000 or more years and it won't happen overnight. What we see now is that the poles move more rapidly than before, and the earth magnetic field intensity decreases. Its strength however is still above average. I doubt whether the magnetic field would completely fall apart considering the relatively long time it takes to complete the shifting event (days at least, years could be very well possible, many years too) compared to the rediculously short time it takes an electron to do the retour trip from pole to pole (0.2 seconds for an electron at 1 earth radius from the surface at the equator). The magnetic field possibly will look quite ugly during the reversal, but an ugly field consisting of multiple poles can provide protection too. maybe less, but the phenomenon is so poorly understood or examined (the last time wxas about 800.000 years ago...) that nobody can tell for sure. WE'll have to wait and see. Considereing the numerous times it has happened before, it won't be the end of the world. We just might have some trouble with it.

russ_watters
2004-Dec-02, 01:24 PM
Solar radiation levels at ground will increase greatly and we may experience a world wide ozone hole which will increase UV insolation. Even if the field simply topples without losing strength the polar ozone holes will follow. Place an ozone hole over the equator and it will be unliveable. Solar radiation (unspecified type) yes, increased UV due to a worldwide ozone hole, no. Ozone is a chemical - oxygen-3. It won't magically disappear with a change in the magnetic properties of the earth.

Argos
2004-Dec-02, 01:59 PM
All the maps in the world will have to be reprinted, because they will be the wrong way up :)

The geographic north (a convention) wonīt be affected by magnetic pole shift. Only the compasses wonīt point to the north. Itīs not a great problem because even now compasses donīt point to the north, really.

iFire
2004-Dec-02, 02:02 PM
Are you all crazy!? The pole shift will cause a swath of destruction unheard of! 99.9% of all the world's species will be killed by the magnetic reversal! I know all this because the aliens that visit me told me.


8-[

jt-3d
2004-Dec-02, 04:59 PM
Well in that case I'll just borrow a hundred grand from a bad a.. loan shark and spend it all on a stripper named Molly Mount.



Wanna hear something funny? My wife's maiden name is Mount. Her first name isn't Molly though. So close.

Nicolas
2004-Dec-02, 06:23 PM
[Helen Lovejoy voice]Somebody pleeeaaase think of the icebears!!!![/Helen Lovejoy voice]

Extravoice
2004-Dec-02, 08:44 PM
Nova had a good program about this a while back....

Here is a link to their Program Page (http://www.pbs.org/wgbh/nova/magnetic/)

Kesh
2004-Dec-03, 04:35 AM
Yeah, that program on Nova was impressive. I loved the computer model projecting what the pole shift would be like.

metal_dragon35
2004-Dec-03, 02:42 PM
wait a sec if the poles slowly change over time like ---|+++ / --+|-++ / -++|--+ / +++|--- will the earths magnetic polls ever be neutral like -+-+|-+-+?would magnetic cumpiss just freak out? :-s i mean what would happen?

A Thousand Pardons
2004-Dec-03, 09:58 PM
wait a sec if the poles slowly change over time like ---|+++ / --+|-++ / -++|--+ / +++|--- will the earths magnetic polls ever be neutral like -+-+|-+-+?would magnetic cumpiss just freak out? :-s i mean what would happen?
There are no monopoles, so far as we know

frogesque
2004-Dec-03, 10:11 PM
wait a sec if the poles slowly change over time like ---|+++ / --+|-++ / -++|--+ / +++|--- will the earths magnetic polls ever be neutral like -+-+|-+-+?would magnetic cumpiss just freak out? :-s i mean what would happen?
There are no monopoles, so far as we know

Mmmm... Three would be possible though - 2 North and one South, now that would cause a bit of confusion

Kesh
2004-Dec-04, 04:24 AM
wait a sec if the poles slowly change over time like ---|+++ / --+|-++ / -++|--+ / +++|--- will the earths magnetic polls ever be neutral like -+-+|-+-+?would magnetic cumpiss just freak out? :-s i mean what would happen?

What apparently happens is that the Earth's magnetic field goes from one big field into dozens of smaller ones, giving you dozens of North and South magnetic poles all over the world. Eventually, they consolidate back into two poles, but at the opposite ends of the planet from before.

A Thousand Pardons
2004-Dec-04, 05:44 PM
What apparently happens is that the Earth's magnetic field goes from one big field into dozens of smaller ones, giving you dozens of North and South magnetic poles all over the world. Eventually, they consolidate back into two poles, but at the opposite ends of the planet from before.
Are you sure? I thought that they had mapped the path of the major dipole as it flipped, and it showed a preference for a particular north-south path.

Kesh
2004-Dec-04, 10:04 PM
There may have been a dominant dipole, but there were also dozens of smaller, weaker dipoles popping up all over the place.

A Thousand Pardons
2004-Dec-05, 04:50 AM
There may have been a dominant dipole, but there were also dozens of smaller, weaker dipoles popping up all over the place.
How do you mean that, and how is that any different than now?

Kesh
2004-Dec-05, 09:58 PM
*sigh* Let me see if I can find one of the graphics. It's... difficult to explain in text. :)

Right now, we have the major dipole with a couple small patches that are 'reversed' from the main magnetic field they're in.

What they showed in that special was that many other magnetic anomalies start showing up as the pole shift begins, from small to very large. Eventually, we end up with a magnetic field that looks like a painted easter egg... patches of "north" magnetics a hundred miles across in the middle of a "south" field, and dozens of these anomalies all over the planet. You might have a "south" magnetic field sitting over the US midwest, a "north covering a similar part of Canada, and another "south" at the physical north pole, etc.

Over time, these anomalies start to die down. As they do, it becomes clear that the dominant field in the northern hemisphere is the "south" magnetic field, and vice versa.

This 'path of dominance' may have a preferred route, but the large anomalies seemed to be fairly random as the poles shifted. And, at the midpoint, they were so frequent and large that there was no discernable "north" or "south" magnetic. Just patches of such fields all over the globe.

Ah, here we go (http://www.pbs.org/wgbh/nova/magnetic/reve-06.html). This is one of the views from the special. Note that, on the surface, it appears that the poles (mostly) follow the specific path you mentioned, while in the core it's much more chaotic and patchy.

The other computer model I saw showed the field more like the large 'bands' of energy surrounding the globe, such as in your average textbook. When the flip is modeled in that one, the various patches of magnetic field are much more pronounced and visible.

Of course, it may be that the latter animation was based on the core magnetics, rather than what we'll notice on the surface. Even so, we're going to have a lot of trouble with compasses for a while when this happens. :)

A Thousand Pardons
2004-Dec-06, 02:22 AM
Right now, we have the major dipole with a couple small patches that are 'reversed' from the main magnetic field they're in.

I don't think so. What do you mean?

Ah, here we go (http://www.pbs.org/wgbh/nova/magnetic/reve-06.html). This is one of the views from the special. Note that, on the surface, it appears that the poles (mostly) follow the specific path you mentioned, while in the core it's much more chaotic and patchy.

The core is pretty chaotic anyway. The downwards projection of the magnetic field would seem to have the (on the surface dominant) dipole field about equal to all the other levels of the field. That's a result of how the fields attentuate with distance.

If all degrees of the magnetic field were about equal on the surface of the core, and that was the source of the Earth's magnetic field (not a bad assumption), then the dipole field would dominate at the surface. The dipole would only really disappear if the field itself disappeared and left only the remnant magnatism at the surface--which is a lot smaller than the dipole field.

Kesh
2004-Dec-06, 08:20 AM
Right now, we have the major dipole with a couple small patches that are 'reversed' from the main magnetic field they're in.

I don't think so. What do you mean?

If I remember from the program, there have been a few magnetic anamolies already detected which fit the pattern of the pole shift. Meaning, patches of 'south' magnetic fields in the northern hemisphere and vice-versa, which cannot be attributed to ferrous materials or other permanant magnets.

A Thousand Pardons
2004-Dec-06, 09:46 AM
If I remember from the program, there have been a few magnetic anamolies already detected which fit the pattern of the pole shift. Meaning, patches of 'south' magnetic fields in the northern hemisphere and vice-versa, which cannot be attributed to ferrous materials or other permanant magnets.
The magnetic field does not line up with the hemispheres, of course, and it is stronger/weaker in some places than others, and those anomalies shift over time (decades or centuries), but I don't think that there are patches of "south" inside of the "north" half of the world.

That said, if the earth were divided into four north/south patches (two of each), it would no longer be said to be a dipole--it would be known as a quadrapole. That's just the technical name, derived from the spherical harmonics used to model the field. In other words, the current field has a dipole component and a quadrapole component (as well as many other, higher degree components), but the dipole component, at the surface, dominates so that the quadrapole contribution is seen as variations in the strength of the field, rather than actual patches of south/north.

DigitalKnight
2004-Dec-06, 04:16 PM
wait a sec if the poles slowly change over time like ---|+++ / --+|-++ / -++|--+ / +++|--- will the earths magnetic polls ever be neutral like -+-+|-+-+?would magnetic cumpiss just freak out? :-s i mean what would happen?
There are no monopoles, so far as we know

Mmmm... Three would be possible though - 2 North and one South, now that would cause a bit of confusion

I don't think so, but I’ll have to look it up in my E-Mag texts when I get home to be sure. From my understanding magnetic fields only exist in a dipole configuration, or a multi-dipole configuration. As far as I know, every magnetic field known has equal numbers of North and South poles.

A Thousand Pardons
2004-Dec-06, 04:27 PM
I don't think so, but I’ll have to look it up in my E-Mag texts when I get home to be sure. From my understanding magnetic fields only exist in a dipole configuration, or a multi-dipole configuration. As far as I know, every magnetic field known has equal numbers of North and South poles.
Their expression at the surface may vary. The earth field approximates a dipole magnet buried in the earth. Imagine two of them, laid south pole to south pole. Then, in each hemisphere, a compass will point away from the equator.

In the diagrams at Kesh's link, the north poles are colored blue, I think, so this example would have three areas--two blues at each end, with a single band of red. If you don't like the idea of the entire equator being a single south pole, bury six bar magnets grouped in pairs like above with their south poles closer to the surface. Then there are two north poles, and three south poles, at the surface.

frogesque
2004-Dec-06, 04:46 PM
DigitalKnight, ATP

I was actually thinkinking along the lines of a Y with two weaker strength N poles and a stronger single S. The analogy would be a strip of magnetized steel split half way and the ends opened out. The nett field would be the same, just redistributed with probably some sort of null point between the arms.

A Thousand Pardons
2004-Dec-06, 05:12 PM
DigitalKnight, ATP

I was actually thinkinking along the lines of a Y with two weaker strength N poles and a stronger single S. The analogy would be a strip of magnetized steel split half way and the ends opened out. The nett field would be the same, just redistributed with probably some sort of null point between the arms.
Depends upon where you place it. The current dipole acts as if it were buried close to the core-mantle boundary (natch, since that is probably where it originates), so if you buried yours in the same manner, the external field would not look too much different than it does now--almost like shifting the "usual" bar magnet a bit south.

frogesque
2004-Dec-06, 05:32 PM
Yep, I follow you - it was just a thought.

What does seem to be evident is that between the mantle and the solid core it's really chaotic and what we see at the surface is a combination of all the little tadpoles and eddy currents acting together to produce the external field.

A Thousand Pardons
2004-Dec-06, 05:52 PM
What does seem to be evident is that between the mantle and the solid core it's really chaotic and what we see at the surface is a combination of all the little tadpoles and eddy currents acting together to produce the external field.
If you model the external field using spherical harmonics, you can show that it originates in the interior (Gauss did this, I think). Since the higher degree terms attentuate with distance, you can back it down to the interior, and at the core-mantle boundary, the dipole is about the same strength as the quadrapole, or any of the other higher degree terms. The dipole is what makes it to the surface.

It's kinda like the Y magnet--if you bury it far enough, it looks like a dipole. So, yes, it probably is pretty chaotic down there. Seems natural that it should move around a bit. :)

DigitalKnight
2004-Dec-06, 07:24 PM
DigitalKnight, ATP

I was actually thinkinking along the lines of a Y with two weaker strength N poles and a stronger single S. The analogy would be a strip of magnetized steel split half way and the ends opened out. The nett field would be the same, just redistributed with probably some sort of null point between the arms.

OK, I see what you are getting at now. For a moment I thougth that you where trying to use some sort of tripole arrangment. #-o

I have a feeling that the field equations for the Y magnet would be, to say the least, messy to work. I really need to reread my E-Mag book.

metal_dragon35
2004-Dec-15, 02:36 PM
when the polls shift will we call south north and north south? :-?

Nicolas
2004-Dec-15, 02:56 PM
That's a matter of definition. As the geographical and magnetical poles aren't coïnciding now, I don't think we will change that. You'd have to turn over all maps and things like that. Just keep things simple and leave antarctica at the bottom. :)

Maybe we should make a pole poll asking whether or not to change names? :D (don't start a poll please :))

A Thousand Pardons
2004-Dec-16, 10:53 AM
Maybe we should make a pole poll asking whether or not to change names? :D (don't start a poll please :))
Maybe we could just do it in Poland, then.

You all are aware that the North Magnetic Pole is a south magnetic pole? So that will be fixed when they switch--no need to change. :)