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Posted

http://www.igpp.ucla.edu/people/mkivelson/Publications/ICRUS1572507.pdf[/size]

"Magnetometer data from Galileos multiple ybys of Ganymede provide signicant, but not unambiguous, evidence that the moon, like its neighboring satellites Europa and Callisto, responds inductively to Jupiters time-varying magnetic eld."

Are they not confirming that Europa and Callisto do "respond(s) inductively to Jupiters time-varying magnetic eld".

Only insomuch as a magnetic field induces currents in conductors, which is the very basis of inductance. The next line after your quote:

...The response is roughly 84% of the response expected for a metallic sphere of the same radius but there may be considerable uncertainty in this estimate. ...

They are attributing the supposed inductance coupling to water as a conductor in Ganymede, not to its dynamo generated magnetic field.

 

That works. :) Nothing there however to counter my arguments about the errors.

 

 

Acme, you must stop by my Plate Tectonic thread sometime, I have some interesting things to share and discuss with you. :)

As I say I have read much of it. I didn't think I could add anything, but I'll have another look as time allows. :)

Posted

Only insomuch as a magnetic field induces currents in conductors, which is the very basis of inductance. The next line after your quote:

They are attributing the supposed inductance coupling to water as a conductor in Ganymede, not to its dynamo generated magnetic field.

 

 

That works. :) Nothing there however to counter my arguments about the errors.

 

Inductance is inductance. You know, Uranus and Neptune's field generators are believed to be warm water and ammonia. Whats good for the goose, I mean Ganymede, is . . . . .

Posted

Inductance is inductance. You know, Uranus and Neptune's field generators are believed to be warm water and ammonia. Whats good for the goose, I mean Ganymede, is . . . . .

:lol: What's good for the bear is not necessarily good for the fox. Regardless of other planets I have seen no reliable study that shows Sol is modulating the strength of Earth's magnetic field.

:lol: What's good for the bear is not necessarily good for the fox even though they are both mammals. Regardless of other planets, I have seen no reliable study that shows Sol is modulating the strength of Earth's magnetic field.

Posted

Regardless of other planets I have seen no reliable study that shows Sol is modulating the strength of Earth's magnetic field.

 

Without Sun, Earth's magnetic field would looks like:

 

earth_mag_field.gif

 

With Sun, Earth's magnetic field looks like:

 

solar_wind_and_mag_field.gif

Posted (edited)

 

Regardless of other planets I have seen no reliable study that shows Sol is modulating the strength of Earth's magnetic field.

Without Sun, Earth's magnetic field would looks like:

 

snip...

With Sun, Earth's magnetic field looks like:

 

snap...

 

On the first drawing, as I have pointed out numerous times Earth's field switches polarity so that is only accurate insofar as it goes for parts of Earth history. Besides that, Earth has islands of reverse polarity that are not modeled by that simplified bar-magnet analogy. Edit: The underlined is actually a misstatement on my part. Earth's magnetic field, or that of any planet, is never a simple bar-magnet because of the dynamics of a geo-dynamo. Moreover, planetary magnetic fields are always accompanied by/deformed by a solar magnetic field because planets always orbit stars.

 

As to the second drawing that only shows that Earth's field is deformed by the Suns', not that Earth's magnetic field strength is modulated by the Sun.

 

Returning, once again, to the Original Post/Thread Title concerning the 10% magnetic field decline, we read this. (Bolding mine.)

 

source: >> http://www.webcitation.org/5nDzbvFyX

Earth's Inconstant Magnetic Field

Our planet's magnetic field is in a constant state of change, say researchers who are beginning to understand how it behaves and why.

...

Earth's magnetic field is changing in other ways, too: Compass needles in Africa, for instance, are drifting about 1 degree per decade. And globally the magnetic field has weakened 10% since the 19th century. When this was mentioned by researchers at a recent meeting of the American Geophysical Union, many newspapers carried the story. A typical headline: "Is Earth's magnetic field collapsing?"

 

Probably not. As remarkable as these changes sound, "they're mild compared to what Earth's magnetic field has done in the past," says University of California professor Gary Glatzmaier.

 

Sometimes the field completely flips. The north and the south poles swap places. Such reversals, recorded in the magnetism of ancient rocks, are unpredictable. They come at irregular intervals averaging about 300,000 years; the last one was 780,000 years ago. Are we overdue for another? No one knows.

 

According to Glatzmaier, the ongoing 10% decline doesn't mean that a reversal is imminent. "The field is increasing or decreasing all the time," he says. "We know this from studies of the paleomagnetic record." Earth's present-day magnetic field is, in fact, much stronger than normal. The dipole moment, a measure of the intensity of the magnetic field, is now 8 × 1022 amps × m2. That's twice the million-year average of 4× 1022 amps × m2.

...

They've also learned what happens during a magnetic flip. Reversals take a few thousand years to complete, and during that time--contrary to popular belief--the magnetic field does not vanish. "It just gets more complicated," says Glatzmaier. Magnetic lines of force near Earth's surface become twisted and tangled, and magnetic poles pop up in unaccustomed places. A south magnetic pole might emerge over Africa, for instance, or a north pole over Tahiti. Weird. But it's still a planetary magnetic field, and it still protects us from space radiation and solar storms. ...

Edited by Acme
  • 1 month later...
  • 1 month later...
Posted

The first set of high-resolution data on Earths magnetic field from ESAs Swarm mission will be unveiled at a conference in Copenhagen, Denmark on 19 June. ...

Earth's Magnetic Field Is Weakening 10 Times Faster Now

 

 

Earth's magnetic field, which protects the planet from huge blasts of deadly solar radiation, has been weakening over the past six months, according to data collected by a European Space Agency (ESA) satellite array called Swarm.

 

The biggest weak spots in the magnetic field which extends 370,000 miles (600,000 kilometers) above the planet's surface have sprung up over the Western Hemisphere, while the field has strengthened over areas like the southern Indian Ocean, according to the magnetometers onboard the Swarm satellites three separate satellites floating in tandem.

...

Scientists already know that magnetic north shifts. Once every few hundred thousand years the magnetic poles flip so that a compass would point south instead of north. While changes in magnetic field strength are part of this normal flipping cycle, data from Swarm have shown the field is starting to weaken faster than in the past. Previously, researchers estimated the field was weakening about 5 percent per century, but the new data revealed the field is actually weakening at 5 percent per decade, or 10 times faster than thought. As such, rather than the full flip occurring in about 2,000 years, as was predicted, the new data suggest it could happen sooner.

...

Still, there is no evidence that a weakened magnetic field would result in a doomsday for Earth. During past polarity flips there were no mass extinctions or evidence of radiation damage. Researchers think power grids and communication systems would be most at risk. ...

Posted

I do not want to get into conspiracy theories, But was looking at where the magnetic fields are strengthening, You cannot but help notice the bright pink area malaysia/indian ocean,

magnetic-field.jpg?1404833682

 

This is near where flight mh370 disappeared,

mh370-route.png?w=540&h=388

 

I wonder if this high magnetic field had anything to do with the loss of this flight, Effecting the instruments (Bermuda trianglish) loss of radios?,

Then you realise america as a no fly base on Diego Garcia,

post-79233-0-06174300-1405027982.gif

 

With what happened at 911, Maybe flight mh370 with the loss of communication flew to close to this base, And never answered hails, So was shot down.

 

What effect would these new high/low magnetic fields have on plane/ship instruments?

Posted (edited)

I do not want to get into conspiracy theories, But was looking at where the magnetic fields are strengthening, You cannot but help notice the bright pink area malaysia/indian ocean,

Then don't. ;)

 

This is near where flight mh370 disappeared,

Not nearly.

 

I wonder if this high magnetic field had anything to do with the loss of this flight, Effecting the instruments (Bermuda trianglish) loss of radios?,

Then you realise america as a no fly base on Diego Garcia,

 

With what happened at 911, Maybe flight mh370 with the loss of communication flew to close to this base, And never answered hails, So was shot down.

I thought we weren't going to get conspiratorial. :rolleyes:

 

What effect would these new high/low magnetic fields have on plane/ship instruments?

The varying magnetic field areas on Earth do affect compasses, but these variations are charted and aircraft & ship pilots are aware of them. Aircraft also use gyroscopic heading indicators and they are not affected by Earth's magnetic field. GPS receivers are also used for navigation and are unaffected by Earth's magnetic field.

 

I ran across this paper in researching this post and I'll be reading it in its entirety ATA. By all means join me. :) >> Marine Magnetic Anomalies, Geomagnetic Field Reversals, and Motions of the Ocean Floor and Continents

This paper summarizes the results of the three previous papers in this series, which have shown the presence of a pattern of magnetic anomalies, bilaterally symmetric about the crest of the ridge in the Pacific, Atlantic, and Indian oceans. By assuming that the pattern is caused by a sequence of normally and reversely magnetized blocks that have been produced by sea floor spreading at the axes of the ridges, it is shown that the sequences of blocks correspond to the same geomagnetic time scale. An attempt is made to determine the absolute ages of this time scale using paleomagnetic and paleontological data. The pattern of opening of the oceans is discussed and the implications on continental drift are considered. This pattern is in good agreement with continental drift, in particular with the history of the break up of Gondwanaland. ...

Edited by Acme
Posted (edited)

Move from Earth Science :

Huh? Are you asking this thread be moved from Speculation?

 

Anyway, the article you started a new thread with today, I cite in post #32 here. :)

 

PS We also have this recent thread which is more-or-less on the same topic.

Protection by the magnetic field It would be a good idea to read that & this thread in their entirety before posting so as not to rehash material already covered.

Hope this is O.K. Moved from Earth Science. Only just come in to our Geology Group. Did not realise you guys were streets ahead. Sorry . But none-the-less, quite an interesting and concise quote. Hope it is some useful contribution.

 

Mike

As I just said, I already cited that article in post #32. Please take off the large font formatting.

Edited by Acme

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