Earth's Magnetic Field may Invert

[Agaricus bisporus]

There has been much talk recently about the possibility of Earth's magnetic field reversing polarity again, as it has apparently done numerous times over the aeons.

This event may be close, or it may be far, far off, but scientists say another flip may be coming "soon".

What never seems to be mentioned is if it does happen how fast will it occur? Will it become evident over a long period, accelerating towards a "null" point, then emerging in the inverted sense? Will it flip quickly? How fast? Hours, weeks, centuries? Does anyone have any idea at all?

What effects will/might it have on climate, weather, the Ionosphere, solar radiation?

How would/could we cope in aviation if this hit us suddenly?

Has anyone developed sound theories about this yet? Any links or ideas?

[Mattuk]

Think this is seen by looking at how seafloor rocks are magnetically aligned.

www.psc.edu/science/Glatzmaier/glatzmaier.html

www.bbc.co.uk

Hope this helps!

Matt

[411A]

Recall in 1957 (International Geophysical Year) this was predicted as 'soon' as well....as was the coming 'little ice age' as it was reported then that the earth average temperature was rapidly cooling......:sad:

[G-ALAN]

The pole flip is actually overdue according to a book I read (I think it is about 1000yrs overdue). When it comes about it will have devastating effecs. I imagine aircraft will still be able to fly no bother but just don't go relying on your compass! Maybe I'm wrong, I don't know exactly how modern INS work in aircraft. :ok:

[PPRuNe Towers]

Still, as long as it's Notamed:} :}

Rob

[AfricanSkies]

HAR!!! good one, Rob :D :D

[RadarContact]

I imagine aircraft will still be able to fly no bother but just don't go relying on your compass!

Don't go out relying on your sunscreen either... :uhoh:

[5milesbaby]

don't wish to scare anyone, but having 'studied' bits of this years ago, the chances of even surviving this aint on our side.

Bit like global warming, its gonna happen anyway, we are just accelerating the processes.

[slim_slag]

5miles,

Are you suggesting we are accelerating the pole flip thing? I've also heard it would get messy during the change, I've read that during previous reversals there has been a signigicant drop in field strength, and we would be fried by all the particles the magnetic field protects us from.

[My names Turkish]

INS stands for inertial navigation system-completely independant of the earths magnetic field.

[visibility3miles]

http://story.news.yahoo.com/news?tmpl=story&cid=624&e=4&u=/ap/pole_flip

magnetic field strength down ten percent in some areas over the last 150 years.

Excerpt:

>>_ At that rate of decline, the field could vanish altogether in 1,500 to 2,000 years, said Jeremy Bloxham of Harvard University.

Hundreds of years could pass before a flip-flopped field returned to where it was 780,000 years ago. But scientists at a meeting of the American Geophysical Union cautioned that scenario is an unlikely one.

"The chances are it will not," Bloxham said. "Reversals are a rare event." <<

[GlueBall]

Not a subject of concern in our lifetime. :ooh:

[andyb79]

i'm sure i heard/read that these flips happen very quickly...
in geology terms! they only take several thousand years!!!
but my drunken memory may be playing tricks on me:=

[Captain Stable]

"Soon" is not measured in light years. A light year is a measure of distance, approx. 9.46 trillion km/5.88 trillion mi.

[fire wall]

Topic was the point of discussion on Discovery Channel last night.
Points of note:
- regular event in geological terms. History has it occuring every 200,000 years but the last one was 700,000 years ago so somewhat overdue for another one.
- mean strength of earth mag. field has reduced 10 % in last 150 yrs which historically has been shown a precurser to a reversal. South Atlantic has a weak point of note which is down 30% on past readings ( via alignment of field found in rocks which, once molten and then cooled take up alignment with existing field of the time)
- last reversal event took place over centuries with "Mag North" moving as much as 60 degrees in a 10 day period. Period defined as time of weak mag activity with mag "North/south" swapping on numerous occasions before settling down.
-finally....."soon" means at best guess the next time Jesus decides to run on at fullback for Jerusalem for his testamonial.

[Voidhawk]

Although opinions seem to vary, here are a few less gloomy quotes from NASA (http://istp.gsfc.nasa.gov/earthmag/magnQ&A1.htm#q6):

...during reversal the magnetic field does not go away, it only gets weaker and develops several more magnetic poles, at unpredictable locations.

...Even today, the magnetic shield is not effective near the magnetic poles, yet the radiation received there on the ground is only slightly higher than anywhere else. The reason is that our main shield against such particles is not the magnetic field of the Earth but the atmosphere, equivalent to some 10 feet of concrete.

...reversing between 1000 and 2000 years from now. It might happen, although the trend may well change.

So we should be OK then :)

[Lu Zuckerman]

Along the same lines, a scientist was giving a lecture on the end of the earth. He stated unequivocally that the earth would be destroyed in about 20 Billion years. A man in the back row screamed out, “How many years?” The scientist replied 20 Billion years. The man in the back breathed a sigh of relief stating, “I thought you said 20 Million years.

:E :E

[G-ALAN]

My names Turkish
I forgot I had even posted on this thread but anyway thank you for your most unwelcome comments. For your information I do know what INS stands for otherwise I wouldn't have mentioned it. My post was written in the hope that other posters may elaborate on it, which they have. If you didn't like it fine, ignore it.

Good day :ugh:

[david viewing]

- last reversal event took place over centuries with "Mag North" moving as much as 60 degrees in a 10 day period. Period defined as time of weak mag activity with mag "North/south" swapping on numerous occasions before settling down.

That will certainly keep the runway painting people busy as they already have been in Ireland, painting out and repainting the numbers. Actually, the old numbers tend to wear through again, giving a bit of a 'oops, wrong airport' fright on finals!

[FlatBread]

I was still under the assumption that (at least some) IRS/INS's are using the magnetic field to allign?

Maybe someone who can comment on this.

[Saab Dastard]

mag "North/south" swapping on numerous occasions before settling down

It's the poor bl00dy homing pigeons I feel sorry for. What carnage!

"Jeez, Mabel, the sun's rising in the West again today, how are we going to get home?"

And the birds flying South for Winter are going to get a bit of a shock as it gets colder...

SD

[M.85]

SAAB:= :D :ok:

M.85