Earth's Magnetic Field Reversal: Impacts on Power Grid

[dimensionless]

If you move a magnet towards a loop of wire it will generate a current in that wire. Could a reversal of the Earth's magnetic field be sudden enough to cause significant damage to the Earth's power grid?

 

[Mk]

No, it takes at least a thousand years, but some have been found to take several hundreds.

 

[Andre]

The duration of magnetic excursions and flips is typically 6000 - 10000 years but in those periods strong departures of the dipole have been recorded with erratic changes within few years. Still not nearly enough to cause strong induction currents but I wouldn't be surprised if a lot of systems would be affected somehow

I had another reply ready for some other new thread that disappeared magically, hate to waste it:
.

Well at least you did some thinking.

If I interpret it correctly you assume that the Earth rotation is causing differential rotation in the fluid core which is supposed to generate the Earth magnetic field. I think that there may be a problem when the magnetic field reverses, which has happened numerous times in the past, without that construction changing accordingly.

Obviously nobody knows exactly what is happening but there are other ideas that seem to be consistent with the observations.

http://www.mala.bc.ca/~earles/reversals.htm
http://www.psc.edu/science/glatzmaier.html

 

[michaelbix]

It's not an "exact" science

While there is a small consensus on the length of time for a pole flip, it is all conjured up in a computer model - which you may observe in motion - http://www.psc.edu/science/Glatzmaier/glatzmaier.html

The approximately 1000-year pole flip period, frankly, I wish were shorter. During the reversal, which some indications show are finally getting underway now (after a delay of almost 700,000 years) the magnetic field generally weakens, the poles themselves drift and nodes of opposite magnetic polarity start to bulge out beyond the liquid magma of the core, and reach the Earth's surface.

This is underway, possibly. The overall magnetic field force has decreased by approximately 15% since measurements began in the late 1800's, and a significant "bulge" of "north" magnetic polarity has surfaced in the south Atlantic, with weaker and similar bulges appearing in opposite hemispheres than where they belong.

If one would like to know what to be concerned about in such an event, I don't believe it is the power grid. In the absence of a coherent magnetic field (there will always be some kind of a field as long as the Earth spins) the Van Allen belts will disappear, and with them the usual protection surface life has against solar ejecta, cosmic rays and the other constituents of the solar wind. The magnetic field (magnetosphere) acts like a shield, bending the solar wind around the earth. In its absence, we will be buffeted by high-energy radiation that will sizzle our cells... and those of every living plant and animal not separated by at least 20' of rock or 100' of water... with damaging, mutation-causing (and probably lethal) effect. The effect lessens toward the poles, but pity all species south of latitude 45 or 50.

 

[LURCH]

??

No, it takes at least a thousand years, but some have been found to take several hundreds.

?

Please clarify.

As has been stated, the flip doesn't happen fast enough to "burn out" power grids. However, the drifting of the poles before they flip could be a problem. Solar radiation at the poles is greater than elsewhere on the planet, because the magnetic field-lines are nearly vertical, allowing radiation to reach the surface. This has not caused a problem in the past because there is no appreciable power grid at either pole. However, if the magnetic pole should drift over more populated areas, this could leave a modern power grid exposed to greater amounts of radiation than normal. During times of increased solar activity, this could result in many more blackouts than would occur otherwise.

 

[DaveC426913]

Even if it did happen rapidly, which it won't, consider what would happen if you had the same power grid in miniature inside a magnetically-insulating soft-iron box, and then took it out.

From zero to Earth's magnetic flux in 2 seconds. Big deal.

 

[LURCH]

...
If one would like to know what to be concerned about in such an event, I don't believe it is the power grid. In the absence of a coherent magnetic field (there will always be some kind of a field as long as the Earth spins) the Van Allen belts will disappear, and with them the usual protection surface life has against solar ejecta, cosmic rays and the other constituents of the solar wind. The magnetic field (magnetosphere) acts like a shield, bending the solar wind around the earth. In its absence, we will be buffeted by high-energy radiation that will sizzle our cells... and those of every living plant and animal not separated by at least 20' of rock or 100' of water... with damaging, mutation-causing (and probably lethal) effect. The effect lessens toward the poles, but pity all species south of latitude 45 or 50.

I've thought the same thing myself, and it seems to make sense. However, I went searching for observed evidence to back up the theory, and it doesn't appear to prove out very well. The flip of the poles was deduced from evidence in the geological record, and this evidence included a rough time refference as to when these polarity inversions have taken place before.

Since the discovery, paleontologists have looked to the fossil record for some evidence of the effect that these events might have on living species. Searching these same time periods for evidence of significant effects on plant and animal life yielded no positive correlation that I can find record of.

(I was hoping to find a link between the polar inversions and punctuated evolution, speculating that increases in genetic mutation during times of increased exposure to cosmic and solar radiation would be accompanied by a corresponding increase in the probability of a positive mutation emerging.)

 

[Andre]

I think we have been here before. Magnetic pole reversals have happened several times in the past without any significant correlation to paleontologic events. The periods of magnetic polarisation are called chrons. Our current chron is called Brunhes after the pole flip of 780,000 years ago succeeding the Matuyama chron, which had several small subchrons of short reversal. Chrons have lasted from about 250,000 years to over 25 million years, on the top of my head. There is no apparent cycle and hence no "late" reversal. Moreover the Earth magnetic field is highly variable and currently extraordinary strong. That would mean that the normal next fluctuation is to go down and that is what we see today. Nothing spectacular, no reason for speculations.

 

[michaelbix]

What is the science of the magnetosphere?

Excuse my ignorance - but the computer models we've seen with respect to the so-called "geodynamo" eddy effects in the various magma layers adjacent to the crust and the inner core are quite complex. When Dr. Glatzmaier's model was wound up and let go, ultimately it did reverse itself without any apparent external stimulus - which would imply a fairly regular flip-flop that would prove out historically. It has not actually been regular.

In the meantime, none of us have ancestors with memories good enough to go back the 700,000-plus years to the last known reversal. Prior to that the reversals (according to Scientific American - April '05 and other sources) occurred more frequently than the 250,000 yr. interval suggested elsewhere here. Now, if Dr. Glatzmaier can model the core reasonably well, has anyone else seen any attempt to model the larger interactive system with the magnetosphere, solar wind, etc. in the event of a reversal?

There should be adequate computing power out there to model such a hypothetical event. Solar/earth physics presupposes an unbroken interactive system from the sun's core to the Earth's core with multiple nuances... very computation heavy but probably doable. Jupiter is a big player in the Earth's magnetosphere (it's been known since the '50's that Jupiter's position can predict whether a solar storm will disrupt Earth electrical/radio transmission for instance) so it's hard to isolate just one or two variables.

Paleological evidence is sketchy... the only thing you can pretend to "know" is what you actually find. Everything you don't find is what you don't know. Humans or human-likes certainly survived pole reversal - although we don't know much "exactly" about that nowadays - there seems to be recent thermoluminescent evidence that Neanderthal, Cro-magnon (and possibly homo sapiens?) overlapped significantly rather than were sequential. [see http://www.daybreaknuclear.com/bortolot_tl.html]

It's awfully hard to say "exactly" what stresses were put on mammalian (and human) life span, newborn survival rates, food supply, genetics, climate adaptation and the like by the periodic magnetic field collapses and reversals. It would be helpful for people reconstructing species history to have some kind of idea.

Example: if, as a consequence of a "mutation event," epihippus were joined by two other horse-like animals (or multiple other horse-like animals) how closely would we be able... today... to tie that to a pole reversal, or not? Especially if most of the disfunctional/impractical mutations died after one or a few generations? Epihippus might live on... but there also might be one or two other variants of epihippus starting a useful evolutionary line. This DID in fact occur for the next 7 - 10 million years with mesohippus and miohippus, both of which appeared suddenly (stimulated by pole events?) and then split still further, with epihippus failing eventually but multiple divergences co-existing (and competing) at the same time, and with surviving/competing lines ultimately moving to zones of different supportive flora. Does the paleologic record match the "chron" record or not?

I'm neither intending "junk science" wild theory or asking lockstep adherence to Darwinian gradualist evolution. I'd simply curious to know if pole reversals could be one of several important variables impacting species survival and/or evolution, and are we in an actual position to make intelligent judgements on the matter - or do we simply lack evidence one way or the other? I think it might be an unanswered, but not unimportant, question in this age of creationism.

Lack of evidence (at the moment) does not explain everything.

 

[Andre]

Well, a lot about magnetic isochrons and reversals here:

http://magician.ucsd.edu/sio247/lectures/html/lecture15/lecture15.html

It's not that there is any known relationship between clear geologic events and magnetic reversal. Note that we also have had several Paleomagnetic excursions (PME) that seem to behave like an incipient reversal. It's starts out the same way and the magnetic field collapses likewise but eventually after a few thousands years the normal polarity is restored. The last one, the Mono Lake PME event (disputed, may have been local), was 26,000 years ago. The Lachamps PME 40,000 years ago was a big one, before that we had the Blake PME at around 100,000 years ago. Evidence for these events is not only magnetic orientation of geologic proxies but also spikes in the atmospheric 10Be production in the ice cores. So we can expect a little more cosmic radiation if something was to happen. However, none of these events can be tied to a specific geologic/climatic/biologic event, and the younger, the better our fossil records are. So, there is no evidence that such an occurrence would have dramatic consequences.

Anyway, modeling and predicting this kind of events is probably a bridge too far. I've asked Glatzmaier if he had included the precession of the equinoxes in his models, as this generates a certain stress on the Core Mantle coupling (Vanyo; see the other thread) and consequently the fluid dynamics of the outer core and hence ultimately on the Earth magnetic field. He had not, this proved to be too complicated.

 

[michaelbix]

Well, a lot about magnetic isochrons and reversals here:

http://magician.ucsd.edu/sio247/lectures/html/lecture15/lecture15.html

"It's not that there is any known relationship between clear geologic events and magnetic reversal. Note that we also have had several Paleomagnetic excursions (PME) that seem to behave like an incipient reversal."

Thanks Andre,
That was a good overview of the current terminology and summaries of key research. I don't know how to determine if there are any studies underway (or planned) that would take a species (ie. epihippus) and plot its evolutionary path in conjunction with chrons and subchron events... there are too many uncertainties, perhaps. I'm primarily working in Bronze and Iron Age north Atlantic prehistory and am trying to keep my eye on factors which may have stressed human and mammal populations in the past 20k years or so (and which may do so again).

In that regard, for instance, I'm curious about why all the horses and horse-derived species that had evolved in North and South America disappeared abruptly from the east side of the Atlantic about 11,000 BC. Probably not a magnetic event, given what I read here. But that's why I'm trying to derive useful information (to my investigations) from a thread like this - as magnetic field events, solar storms and related solar system phenomena had effects upon pre-technological societies as well as modern ones. As I said, sorry I come in as such a generalist.

 

[Andre]

Well I just finished that study about the demise of the Megafauna during the Pleistocene Holocene transition.

This was the major breakthrough:; Since then the files and records have boomed and I'm not able to limit the story within a hundred pages or so. Just for peaking ahead, http://home.wanadoo.nl/bijkerk/extinctions_climate_refs.pdf of the paper under construction.

Anyway, recommending the links in the last post. http://home.wanadoo.nl/bijkerk/BB.ppt

Finally I'm going to tell all about it here tuesday next week in Arnhem Holland, unfortunately, however in Dutch.

You may know my co-speaker, http://www.findarticles.com/p/articles/mi_hb3418/is_200012/ai_n8173967

Nevertheless, everybody is welcome.

 

[StephSommy]

wat about astro physics?

 

[Andre]

with regards to what subject? I'm afraid we got this thread miles off track

 

[ckaspereli]

The real issue is whether and at what rate the Earth's molten iron core is cooling. Once it drops below some threshold (? kelvin) the magnetic field will be inadequate to maintain a liveable atmosphere or protect us from solar radiation. Earth will evolve into another dead planet like Mars.

http://focus.aps.org/story/v19/st3
http://www.sciencedaily.com/releases/2008/02/080208091314.htm

 

[DaveC426913]

I'd say the real issue is that the poles have shifted several times between the last post to this thread and yours.

I think the cooling of the Earth's core is on the order of billions of years, though I have no refs yet. We have bigger fish to fry before then.

 

[Borek]

The real, real issue here is that this thread is 5 years old and new post was off topic.

Locked.