Free Republic
Browse · Search
News/Activism
Topics · Post Article

Skip to comments.

Earth Loses Magnetism
BBC ^ | 1-1-2004 | Molly Bently

Posted on 01/01/2004 9:49:40 AM PST by blam

Earth loses its magnetism

By Molly Bentley
in San Francisco

Scientists have known for some time that the Earth's magnetic field is fading.

The field is mainly dipolar - but there are anomalies

Like a Kryptonite-challenged Superman, its strength has steadily and mysteriously waned, leaving parts of the planet vulnerable to increased radiation from space.

Some satellites already feel the effects.

What is uncertain is whether the weakened field is on the way to a complete collapse and a reversal that would flip the North and South Poles.

Compasses pointing North would then point South.

It is not a matter of whether it will happen, but when, said scientists who presented the latest research on the subject at a recent meeting of the American Geophysical Union in San Francisco.

But when is hard to pinpoint. The dipole reversal pattern is erratic.

"We can have periods without reversals for many millions of years, and we can have four or five reversals within one million years," said Yves Gallet, from Institut de Physique du Globe de Paris, France, who studies the palaeomagnetic record and estimates that the current decay started 2,000 years ago.

Flip or flop

Over the last century and a half, since monitoring began, scientists have measured a 10% decline in the dipole.

At the current rate of decline it would take 1,500 to 2,000 years to disappear.

SEAFLOOR RECORDER

* As molten rock rises, spreads out and cools, magnetised minerals record field direction
* Over millions of years, the seafloor rocks retain a 'barcode' of pole reversals
* These pole reversal events may take perhaps 10,000 years to complete
* The last major pole flip appears to have been about 780,000 years ago

A particular weakness in the field has been observed off the coast of Brazil in the so-called Southern Atlantic Anomaly. Here, eccentricities in the Earth's core have caused a "dip" in the field, leaving it 30% weaker than elsewhere.

The extra dose of radiation creates electronic glitches in satellites and spacecraft that fly through it. Even the Hubble telescope has been affected.

Magnetic reversals were always preceded by weakened magnetic fields, said Dr Gallet, but not all weakened fields bring on a flip-flop.

The Earth's invisible shield could also grow back in strength. "Then sometime, maybe 10,000 years from now, the dipole will decay again and that will lead to a reversal," said Harvard physicist Jeremy Bloxham.

The theme was recently taken up by Hollywood in the movie The Core, in which the Earth's core mysteriously stops spinning, effectively turning off the electromagnetic field.

The movie is nonsense, scientists told BBC News Online, except that the Earth's magnetic field is generated by activity deep inside it.

Iron record

The heat of the solid inner core keeps the molten cocktail of nickel and iron churning in the outer core, which generates a magnetic field.

It is not known how the core behaves exactly, but scientists have a general understanding of how electrical and fluid currents and magnetic field lines all interact to produce the field we experience outside Earth.

"If we had the equivalent of a space probe that went into the core and made measurements for us, that would tell us a tremendous amount "
Jeremy Bloxham, Harvard

Imagine the magnetic field lines within the core "twisting like spaghetti," said Peter L Olson, geophysics professor at Johns Hopkins University.

As they wind and kink around each other, their interaction can accentuate the magnetic field or diminish it.

"Depending on how it's kinked," he said, "it can be helpful or harmful."

The last time the field lines kinked into a dipole reversal was 780,000 years ago.

By studying seafloor sediment and lava flows, scientists can reconstruct the magnetic field patterns of the past. Iron in lava, for example, points in the direction of the then-existing field and is frozen in that orientation as the lava cools and hardens.

According to Dr Gallet, the oldest reversal that has been studied by lava flows comes from Greenland, dated at 16 million years. The time between reversals varies from a thousand to millions of years.

Global light show

So is the Earth about to flip? The safe bet may disappoint screenplay writers everywhere.

"Chances are we're not," said Dr Bloxham. "Reversals are rare events."

And they would certainly not threaten life on Earth as they do in science fiction. Although there would be extra radiation exposure to satellites and some airplanes, there would also be enough of a residual field to provide protection to people, and certainly no more radiation than what is observed at the poles, where the field lines currently dip.

Supercomputers have modelled the pole flipping process (Image: Los Alamos Nat Lab)

But there would be some bizarre readjustment. Prior to Earth's poles re-establishing themselves, a period of disorder would produce multiple poles, according to Dr Bloxham, which may make backwoods camping tricky.

"Getting around using a magnetic compass would be a more complicated endeavour," he said.

A collapse would also produce a great increase in auroral activity - the beautiful display of lights generated by solar particles that follow the magnetic field lines down into the atmosphere.

And there would be plenty to time to grab a camera - the reversal is gradual.

This would give animals which use the magnetic field for navigation, such as some birds, turtles and bees, time to reorient themselves.

"They'd go through many generations in the period in which the field was entering the phase of reversal," said Dr Bloxham. "Presumably they would learn new behaviour patterns to accommodate it."

Space within

As for the ozone layer - which was thought to be vulnerable without a protective shield - the effects would be negligible unless there was a super-solar proton event, said Charles H Jackman, an atmospheric physicist at the US space agency's Goddard Flight Center, referring to the high-energy radiation that can accompany solar flares.

The charged particles zinging down to Earth, said Dr Jackman, break apart molecules of nitrogen, whose atoms go on to form nitric oxide, which devours up ozone.

This happens all the time, but the effects would be increased during a magnetic reversal or diminished magnetic field.

Fluctuations and movement of field strength across the globe are recorded

But he said scientists saw no significant change in ozone depletion due to the Southern Atlantic Anomaly. In any case, the ozone layer would bounce back quickly from the heavy solar bombardment, healing itself in just two to three years, according to Dr Jackman.

This is not the timeline associated with anthropogenic chlorofluorocarbons.

"Chlorofluorocarbons have a much longer lifetime in the atmosphere than does the nitric oxide and its associated constituents," he said.

But all these scenarios are of an indeterminate future. The Earth's interior will remain unexplored for a long time to come - only in science fiction can humans or their equipment survive the 5,500 Celsius temperature in the core to study its activity.

"If we had the equivalent of a space probe that went into the core and made measurements for us, that would tell us a tremendous amount," said Dr Bloxham. "Hollywood may be able to do these things, but we can't."


TOPICS: News/Current Events
KEYWORDS: catastrophism; crevolist; earth; environment; loses; magneticfield; magnetism; poleshift
Navigation: use the links below to view more comments.
first 1-5051-88 next last

1 posted on 01/01/2004 9:49:41 AM PST by blam
[ Post Reply | Private Reply | View Replies]

To: blam
Hmmm ... must be a slow news day huh?
2 posted on 01/01/2004 9:52:59 AM PST by _Jim ( <--- Ann Coulter speaks on gutless Liberals (RealAudio files))
[ Post Reply | Private Reply | To 1 | View Replies]

To: blam
"Magnetic loss of earth increases under Bush Presidency"

"Wes Clark introduces 8 point plan to restore Magnetism"

3 posted on 01/01/2004 9:53:22 AM PST by Semper Paratus
[ Post Reply | Private Reply | To 1 | View Replies]

To: blam
I want to be the first to say it:

"It's George Bush's fault" :o)
4 posted on 01/01/2004 9:55:07 AM PST by Rhetorical pi2
[ Post Reply | Private Reply | To 1 | View Replies]

To: blam
Magnetism is not as attractive as it used to be.
5 posted on 01/01/2004 9:56:26 AM PST by Consort
[ Post Reply | Private Reply | To 1 | View Replies]

To: blam
This is more proof that we should pass Kyoto and not eat at McDonald's. And stop the disparity between rich and poor nations, which causes this imbalance. This might also be caused by all the bombs being dropped in Afghanistan and Iraq on babies.
6 posted on 01/01/2004 9:57:36 AM PST by Koblenz (There's usually a free market solution)
[ Post Reply | Private Reply | To 1 | View Replies]

To: blam
Dammit!! I was beaten by 1 minute 45 seconds!!!

...and also beaten by someone with a funnier line!
7 posted on 01/01/2004 9:57:47 AM PST by Rhetorical pi2
[ Post Reply | Private Reply | To 1 | View Replies]

To: blam
At the current rate of decline it would take 1,500 to 2,000 years to disappear.

I can hardly wait.

8 posted on 01/01/2004 10:02:04 AM PST by curmudgeonII (In the interim perhaps I could read some of the speeches of Al Gore.)
[ Post Reply | Private Reply | To 1 | View Replies]

To: Consort; _Jim; blam
Consort wrote:
Magnetism is not as attractive as it used to be.




Seems to have attracted one of our flyers..

Nice article Blam.. Keep em coming.


9 posted on 01/01/2004 10:02:21 AM PST by tpaine (I'm trying to be 'Mr Nice Guy', but FRs flying monkey squad brings out me devils. Happy New Year!)
[ Post Reply | Private Reply | To 5 | View Replies]

To: Semper Paratus
"Magnetic loss of earth increases under Bush Presidency"

Yup..it's Bush's fault.

Oops, maybe it's a good thing.
Then AlGore invented it.

10 posted on 01/01/2004 10:02:51 AM PST by evad (Happy New Year..Live Long And Prosper)
[ Post Reply | Private Reply | To 3 | View Replies]

To: blam
Is this why I'm having to wrap my feet around my computer chair to keep from smacking into the ceiling?
11 posted on 01/01/2004 10:03:29 AM PST by Johnny_Cipher (Dimension Zero)
[ Post Reply | Private Reply | To 1 | View Replies]

To: blam
No wonder I can jump higher.

And the scale says I lost 20 pounds also!
12 posted on 01/01/2004 10:06:31 AM PST by 11th Earl of Mar
[ Post Reply | Private Reply | To 1 | View Replies]

To: tpaine
It doesn't have the drawing power it once had.
13 posted on 01/01/2004 10:07:59 AM PST by Consort
[ Post Reply | Private Reply | To 9 | View Replies]

To: blam
This would give animals which use the magnetic field for navigation, such as some birds, turtles and bees, time to reorient themselves.

If I recall my college courses correctly, this theory was discounted in the 50's.

It would be shocking if the magnetic fields stayed exactly the same over the years. (Same goes for the global temperature, sea levels, rain patterns, CO2 levels ...) If the magnetic fields were increasing we would be reading an article about how dangerous this is.


gitmo
14 posted on 01/01/2004 10:08:54 AM PST by gitmo (Who is John Galt?)
[ Post Reply | Private Reply | To 1 | View Replies]

To: blam
The heat of the solid inner core keeps the molten cocktail of nickel and iron churning in the outer core, which generates a magnetic field.

Something about that doesn't make sense to me. Simply moving a metallic substance around and around shouldn't be able to generate a magnetic field, unless the substance is charged for some reason. But what would be causing it to be charged, and where's the balance of the charge gone to?

15 posted on 01/01/2004 10:10:18 AM PST by inquest (The only problem with partisanship is that it leads to bipartisanship)
[ Post Reply | Private Reply | To 1 | View Replies]

To: blam
"If we had the equivalent of a space probe that went into the core and made measurements for us, that would tell us a tremendous amount," said Dr Bloxham. Hollywood may be able to do these things, but we can't."

Rule number one in the serach for legitimacy:

Anytime one makes even a passing reference to the movie "The Core" no matter if it was a lame attempt to insert humor into the article by way of a disparaging remark, has not only failed but should now and forever be banned from any position of responsibility higher than say professional dog curber.

16 posted on 01/01/2004 10:12:53 AM PST by Mad Dawgg (French: old Europe word meaning surrender)
[ Post Reply | Private Reply | To 1 | View Replies]

To: inquest
It's the proliferation of refrigerator magnets. They have a cumulative effect that is cancelling out the earth's field. ;-)
17 posted on 01/01/2004 10:13:49 AM PST by NewHampshireDuo
[ Post Reply | Private Reply | To 15 | View Replies]

To: blam; RadioAstronomer
Some interesting science threads lately.
18 posted on 01/01/2004 10:15:42 AM PST by farmfriend ( Isaiah 55:10,11)
[ Post Reply | Private Reply | To 1 | View Replies]

To: blam
And they would certainly not threaten life on Earth as they do in science fiction. Although there would be extra radiation exposure to satellites and some airplanes, there would also be enough of a residual field to provide protection to people, and certainly no more radiation than what is observed at the poles, where the field lines currently dip.

[snip]

This would give animals which use the magnetic field for navigation, such as some birds, turtles and bees, time to reorient themselves.

"They'd go through many generations in the period in which the field was entering the phase of reversal," said Dr Bloxham. "Presumably they would learn new behaviour patterns to accommodate it."

Anyone else find it very interesting how the scientists are so blase about these environmental changes, when they're naturally (though completely haphazardly) occurring, but if man were to cause these exact same changes, there'd be no end to the gloom and doom we'd be hearing?

19 posted on 01/01/2004 10:15:49 AM PST by inquest (The only problem with partisanship is that it leads to bipartisanship)
[ Post Reply | Private Reply | To 1 | View Replies]

To: blam
How did a woolly mammoth freeze with tropical flowers in his mouth and stomach?
20 posted on 01/01/2004 10:17:34 AM PST by Yosemitest
[ Post Reply | Private Reply | To 1 | View Replies]

To: blam
Just saw Howard Dean Speak about this on a morning show His Blue ribbon panel has already been working on this they found that It is the recent increase in refrigartor magnets use

21 posted on 01/01/2004 10:18:22 AM PST by al baby (Ice cream does not have bones)
[ Post Reply | Private Reply | To 1 | View Replies]

To: blam
Wow, just about the same time as increased solar flare activity. Interesting coincidence.
22 posted on 01/01/2004 10:25:59 AM PST by dr_who_2
[ Post Reply | Private Reply | To 1 | View Replies]

To: blam
I have 15 magnets on my 'fridge.
23 posted on 01/01/2004 10:26:25 AM PST by muleskinner ("Oh, please")
[ Post Reply | Private Reply | To 1 | View Replies]

To: Yosemitest
How did a woolly mammoth freeze with tropical flowers in his mouth and stomach?

No mammoth has been found with tropical flowers in its stomach.

Some have been found having eaten flowers, but flowering plants also grow in far northern latitudes.

All that proves is that the mammoths may have been caught in a sudden blizzard.

What the book of Hebrews has to do with global climate change(which has always occurred) is not clear to me

24 posted on 01/01/2004 10:27:09 AM PST by WackyKat
[ Post Reply | Private Reply | To 20 | View Replies]

To: blam
Earth's magnetic field is fading

I knew something felt different.

25 posted on 01/01/2004 10:27:53 AM PST by boycott
[ Post Reply | Private Reply | To 1 | View Replies]

To: blam
Tom Daschle is deeply saddened.
26 posted on 01/01/2004 10:28:54 AM PST by freedumb2003 (Peace through Strength)
[ Post Reply | Private Reply | To 1 | View Replies]

To: al baby
You forgot to mention that the Bush-Cheney 2000 refrigerator magnets are suspected to be especially responsible for this distributed distortion effect, and that the Nation Institute of Science has just awarded a large, multi-year grant to a group of physicists at Berkeley, who suspect that Bush-Cheney bumper stickers may be contributing in some way that is not yet fully understood.
27 posted on 01/01/2004 10:29:33 AM PST by Cicero (Marcus Tullius)
[ Post Reply | Private Reply | To 21 | View Replies]

To: blam
Earth loses its magnetism while politics becomes more polarized every day. See, they are sucking the magnetism as well as the oxygen out of the ecosystem! It's not Bush's fault, it is HillaryTM!!!
28 posted on 01/01/2004 10:41:02 AM PST by NonValueAdded ("Either you are with us, or you are with the terrorists." GWB 9/20/01)
[ Post Reply | Private Reply | To 1 | View Replies]

To: blam
Quick! Everyone bury your magnets!
29 posted on 01/01/2004 10:43:24 AM PST by mtbopfuyn
[ Post Reply | Private Reply | To 1 | View Replies]

To: boycott
As for the ozone layer - which was thought to be vulnerable without a protective shield - the effects would be negligible unless there was a super-solar proton event, said Charles H Jackman, an atmospheric physicist at the US space agency's Goddard Flight Center, referring to the high-energy radiation that can accompany solar flares.

The charged particles zinging down to Earth, said Dr Jackman, break apart molecules of nitrogen, whose atoms go on to form nitric oxide, which devours up ozone.

This happens all the time, but the effects would be increased during a magnetic reversal or diminished magnetic field.


ANOTHER! global warming/OZONE hole problem-

refridgerator magnets will be banned!
30 posted on 01/01/2004 10:44:18 AM PST by mj1234
[ Post Reply | Private Reply | To 25 | View Replies]

To: blam
"We've GOT HIM! There's your 2004 platform issue folks - go GET BUSH!"

"I'm as happy as a little girl!"

31 posted on 01/01/2004 10:46:58 AM PST by Caipirabob (Democrats.. Socialists..Commies..Traitors...Who can tell the difference?)
[ Post Reply | Private Reply | To 1 | View Replies]

To: blam
Does this mean that when I flush my toilet it will flow in the opposite direction?

A very Happy New Year to you, sir!

32 posted on 01/01/2004 10:49:07 AM PST by EggsAckley (......................... IT'S NOT MY FAULT ! ! ! ...................................)
[ Post Reply | Private Reply | To 1 | View Replies]

To: blam
What a bunch of HORSE CRAP!
33 posted on 01/01/2004 10:51:23 AM PST by RoseofTexas (r)
[ Post Reply | Private Reply | To 1 | View Replies]

To: Yosemitest
How indeed?


34 posted on 01/01/2004 10:52:46 AM PST by BenLurkin (Socialism is Slavery)
[ Post Reply | Private Reply | To 20 | View Replies]

To: blam
Halliburton.
35 posted on 01/01/2004 11:00:29 AM PST by samtheman
[ Post Reply | Private Reply | To 1 | View Replies]

To: WackyKat

36 posted on 01/01/2004 11:11:46 AM PST by Yosemitest
[ Post Reply | Private Reply | To 24 | View Replies]

To: blam
Must be why I was having trouble walking last night...stupid magnetism!
37 posted on 01/01/2004 11:13:56 AM PST by tongue-tied
[ Post Reply | Private Reply | To 1 | View Replies]

To: blam
The number 780,000 years ago sounded familiar so, just on a whim, I did a google search on the term "780,000 years ago" and got 947 hits.  I found this strange until I realized that scientists were dating archaeological findings based on the magnetic pole location.  Just thought it might be interesting to somebody, and perhaps my explanation is too simplistic.
 
here are a few of the hits:
 
 
Searched the web for "780,000 years ago" Results 1 - 10 of about 947.
 
 
Possible human ancestors lived in Spain 780,000 years ago
 
 
Scientists say Israeli site dates back 780,000 years
 
Homo antecessor
... The human fossils and lithic industry were found in association with fauna
at a level dated before 780,000 years ago, and the remains were found in ...
 
 
Natural History: Promised land: several million years ago tectonic ...
... according to African techniques and found at a site just north of Lake Tiberias,
suggest another round of emigration out of Africa about 780,000 years ago. ...
 
Grand Canyon: grand and young
... level within the last 400,000 years, and their colleague George Billingsley, at
USGS in Flagstaff, has found dikes that crossed the canyon 780,000 years ago. ...

 

38 posted on 01/01/2004 11:16:48 AM PST by Lokibob
[ Post Reply | Private Reply | To 1 | View Replies]

To: blam

39 posted on 01/01/2004 11:17:09 AM PST by putupon (New Years Resolution #1: Never post a babelfish.com translation again in this Tagline.)
[ Post Reply | Private Reply | To 1 | View Replies]

To: inquest
I would assume that the flowing metal could build up a charge similar to the charges created in the flowing air of a thunderstorm.

I'm not sure a charge is necessary...is there a charge on a bar magnet? There is no current flowing in it, but it has a field.

Once again, I assume that if you allow molten ferrous material to mingle long enough, the atoms will align themselves to each other. Add to that the complex flow patterns resulting from convection and the earth's rotation.....and all bets are off.

40 posted on 01/01/2004 11:17:35 AM PST by SC Swamp Fox (Aim small, miss small.)
[ Post Reply | Private Reply | To 15 | View Replies]

To: blam
We're all gonna die!!!!

41 posted on 01/01/2004 11:29:05 AM PST by Lazamataz (G-d gave us free will. The government took it away.)
[ Post Reply | Private Reply | To 1 | View Replies]

To: Lokibob
Possible human ancestors lived in Spain 780,000 years ago

No way.....

42 posted on 01/01/2004 11:30:35 AM PST by Lazamataz (G-d gave us free will. The government took it away.)
[ Post Reply | Private Reply | To 38 | View Replies]

To: Semper Paratus
"Wes Clark introduces 8 point plan to restore Magnetism"

Dean advisor, Professor Albert Gore, has stated that Dean would utilize the Gore plan to restore the Earth's magnatism.

The Gore Plan would direct NASA to collect many asteroids and then form them into a giant magnet. The giant magnet would then be rubbed over the Earth, south to north, to restore the Earth's magnetic field.

43 posted on 01/01/2004 11:30:41 AM PST by TC Rider (The United States Constitution 1791. All Rights Reserved.)
[ Post Reply | Private Reply | To 3 | View Replies]

To: blam
At the current rate of decline it would take 1,500 to 2,000 years to disappear.

News you can use.

44 posted on 01/01/2004 11:32:12 AM PST by Faraday
[ Post Reply | Private Reply | To 1 | View Replies]

To: Lazamataz
I'm not going to argue, Laz, just click on the links.
45 posted on 01/01/2004 11:35:48 AM PST by Lokibob
[ Post Reply | Private Reply | To 42 | View Replies]

To: *crevo_list; VadeRetro; jennyp; Junior; longshadow; RadioAstronomer; Physicist; LogicWings; ...
PING. [This ping list is for the evolution side of evolution threads, and sometimes for other science topics. FReepmail me to be added or dropped.]
46 posted on 01/01/2004 11:35:59 AM PST by PatrickHenry (Hic amor, haec patria est.)
[ Post Reply | Private Reply | To 43 | View Replies]

To: blam
"Atkin's Vidicated -- Everyone Loses Weight!"
Doctors struggle to explain why
obese no longer means overweight!

47 posted on 01/01/2004 11:41:44 AM PST by TheRightGuy (ERROR CODE 018974523: Random Tagline Compiler Failure)
[ Post Reply | Private Reply | To 1 | View Replies]

To: Lokibob
I'm not going to argue, Laz, just click on the links.

I hate clicking on the links.


48 posted on 01/01/2004 11:43:13 AM PST by Lazamataz (G-d gave us free will. The government took it away.)
[ Post Reply | Private Reply | To 45 | View Replies]

To: TheRightGuy
OUCH!
< /hangover>

magnetism does not equal gravity

49 posted on 01/01/2004 11:44:40 AM PST by TheRightGuy (ERROR CODE 018974523: Random Tagline Compiler Failure)
[ Post Reply | Private Reply | To 47 | View Replies]

To: Semper Paratus
Thanks for the laugh ::))
50 posted on 01/01/2004 11:45:06 AM PST by ostephani
[ Post Reply | Private Reply | To 3 | View Replies]


Navigation: use the links below to view more comments.
first 1-5051-88 next last

Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.

Free Republic
Browse · Search
News/Activism
Topics · Post Article

FreeRepublic, LLC, PO BOX 9771, FRESNO, CA 93794
FreeRepublic.com is powered by software copyright 2000-2008 John Robinson