# How is the earth's magnetic field flipping going to knock out the US power grid? **URL:** \ **Category:** Factual Questions\ **Created:** [July 13, 2004, 5:20am UTC](https://boards.straightdope.com/t/how-is-the-earths-magnetic-field-flipping-going-to-knock-out-the-us-power-grid/254852 "2004-07-13T05:20:55Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![astro](https://avatars.discourse-cdn.com/v4/letter/a/9dc877/32.png) [@astro](https://boards.straightdope.com/u/astro)\ **Post date:** [July 13, 2004, 5:20am UTC](https://boards.straightdope.com/t/how-is-the-earths-magnetic-field-flipping-going-to-knock-out-the-us-power-grid/254852/1 "2004-07-13T05:20:55Z")
Even if it does, [per this article](http://www.drudgereport.com/flash1.htm), how is that going to affect the power distribution grid? The earth’s magnetic fields is extremely weak compared to AC land lines. How would a magnetic polarity flip blow anything out? [NYT: COLLAPSE OF THE EARTH’S MAGNETIC FIELD ACCELERATES](http://www.drudgereport.com/flash1.htm) > [@](#): > > The collapse of the earth’s magnetic field, which both guards the planet and guides many of its creatures, appears to have started in earnest about 150 years ago, the NY TIMES is planning to report on Page Ones Tuesday. > > Science reporter Bill Broad has filed a report, according to newsroom sources, which explores how: 'The field’s strength has waned 10 percent to 15 percent so far and this deterioration has accelerated of late, increasing debate over whether it portends a reversal of the lines of magnetic force that normally envelop the earth." > > Broad explains: “During a reversal, the main field weakens, almost vanishes, and then reappears with opposite polarity. Afterward, compass needles that normally point north would point south, and during the thousands of years of transition much in the heavens and Earth would go askew.” > > Broad claims: “A reversal could knock out power grids, hurt astronauts and satellites, widen atmospheric ozone holes, send polar auroras flashing to the equator and confuse birds, fish and migratory animals that rely on the steadiness of the magnetic field as a navigation aid.” ---
**Author:** ![Thaumaturge](https://avatars.discourse-cdn.com/v4/letter/t/858c86/32.png) [@Thaumaturge](https://boards.straightdope.com/u/Thaumaturge)\ **Post date:** [July 13, 2004, 5:35am UTC](https://boards.straightdope.com/t/how-is-the-earths-magnetic-field-flipping-going-to-knock-out-the-us-power-grid/254852/2 "2004-07-13T05:35:00Z")
The feild doesn’t switch all at once. Small regions of the earth’s surface have already experienced the switch IIRC, mainly in Africa. Since the switch likely is a gradual weakening and gradual reversal, I doubt the switch itself will do anything to the powergrid. The only thing I can figure is the weakening of the magnetic feild would let charged particles from the sun strike anywhere, exacerbating the effects of a coronal mass discharge headed towards earth. ---
**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\ **Post date:** [July 13, 2004, 5:40am UTC](https://boards.straightdope.com/t/how-is-the-earths-magnetic-field-flipping-going-to-knock-out-the-us-power-grid/254852/3 "2004-07-13T05:40:40Z")
The earth’s magnetic field blocks the solar wind from hitting our atmosphere. With a reduced field, we’ll experience more [Geomagnetic storms](http://geohazards.cr.usgs.gov/factsheets/html_files/geomag/geomag.html) of the sort that [knocked out much of Canada’s power grid in 1989:](http://www.utoronto.ca/env/nh/pt2ch2-2-8.htm) > [@](#): > > Geomagnetic storms take place during times of intense solar flare activity. The high-energy particles racing around the upper atmosphere, trying tocomplete the circuit and return to outer space, are too numerous for the natural atmospheric circuit to handle. Excess particles move down into the lower atmosphere, towards the Earth’s surface, in order to build a circuit. In areas where the ground is not a good conductor (e.g. the Canadian Shield), they seek out other possibilities. Prime targets are north-south-oriented power transmission lines. Even high-tension power lines cannot handle this amount of energy – ~500,000 Megawatts (Lerner, 1995) – hence, power surges and eventual power failure can ensue. ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [July 13, 2004, 5:41am UTC](https://boards.straightdope.com/t/how-is-the-earths-magnetic-field-flipping-going-to-knock-out-the-us-power-grid/254852/4 "2004-07-13T05:41:29Z")
Alarmist bullshit. True, a _very_ rapidly-collapsing magnetic field can induce high voltages across conductors, but any putative reversal of Earth’s field (yes, they _do_ appear to happen periodically) is going to take thousands of years. During which time, birds and other animals with a magnetic sense will grow to adapt (or not–that’s what evolution is all about, after all). I can’t speak to atmospheric effects, because there’s some pretty complex interactions happening up there, but I suspect it would be less than spectacular–as I said, field reversals do happen, and life has managed to survive them just fine. Other than your compass no longer working correctly, I can’t think of any devastating technological effects. If we can’t adapt our navigational technology to handle somethign like this, then I have little hope for us as a species. 😉 ---
**Author:** ![Askance](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/askance/32/8281_2.png) [@Askance](https://boards.straightdope.com/u/Askance)\ **Post date:** [July 13, 2004, 5:45am UTC](https://boards.straightdope.com/t/how-is-the-earths-magnetic-field-flipping-going-to-knock-out-the-us-power-grid/254852/5 "2004-07-13T05:45:30Z")
The earth’s magnetic field, while weak, is enormous in extent. It protects us against a great deal of cosmic radiation. Presumably the thinking is that if that gets through it can set up large-scale currents in the grid. BTW how come your title only mentions the US power grid? Do you feel it would be particularly vulnerable compared to Canadian or European grids, for instance? From the info you quoted the source just said “power grids”. ---
**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\ **Post date:** [July 13, 2004, 5:56am UTC](https://boards.straightdope.com/t/how-is-the-earths-magnetic-field-flipping-going-to-knock-out-the-us-power-grid/254852/6 "2004-07-13T05:56:26Z")
> [@Q.E.D.](#): > > Alarmist bullshit. Of course, **astro** linked to Drudge’s BS. Here’s the actual New York Times article: [Will Compasses Point South?](http://www.nytimes.com/2004/07/13/science/13magn.html) Despite the title, it’s a pretty good read. ---
**Author:** ![Grey](https://avatars.discourse-cdn.com/v4/letter/g/b782af/32.png) [@Grey](https://boards.straightdope.com/u/Grey)\ **Post date:** [July 13, 2004, 11:37am UTC](https://boards.straightdope.com/t/how-is-the-earths-magnetic-field-flipping-going-to-knock-out-the-us-power-grid/254852/7 "2004-07-13T11:37:09Z")
Think of the aurora displays! ---
**Author:** ![RunSilent](https://avatars.discourse-cdn.com/v4/letter/r/e0b2c6/32.png) [@RunSilent](https://boards.straightdope.com/u/RunSilent)\ **Post date:** [July 13, 2004, 11:46am UTC](https://boards.straightdope.com/t/how-is-the-earths-magnetic-field-flipping-going-to-knock-out-the-us-power-grid/254852/8 "2004-07-13T11:46:11Z")
It may be time to unpack and assemble all 1920s style death rays… ---
**Author:** ![astro](https://avatars.discourse-cdn.com/v4/letter/a/9dc877/32.png) [@astro](https://boards.straightdope.com/u/astro)\ **Post date:** [July 13, 2004, 12:16pm UTC](https://boards.straightdope.com/t/how-is-the-earths-magnetic-field-flipping-going-to-knock-out-the-us-power-grid/254852/9 "2004-07-13T12:16:27Z")
> [@Squink](#): > > Of course, **astro** linked to Drudge’s BS. > Here’s the actual New York Times article: [Will Compasses Point South?](http://www.nytimes.com/2004/07/13/science/13magn.html) > Despite the title, it’s a pretty good read. The article was not yet online last night at the time I posted the question re the Drudge synopsis of the upcoming (at that time) article, and was a relatively accurate reflection of the author’s claims. I was just curious about the “how” in the power grids claims which are identical to those in the article per the quote below. Directly from the article you linked - > [@](#): > > A reversal could knock out power grids, hurt astronauts and satellites, widen atmospheric ozone holes, send polar auroras flashing to the equator and confuse birds, fish and migratory animals that rely on the steadiness of the magnetic field as a navigation aid. But experts said the repercussions would fall short of catastrophic, despite a few proclamations of doom and sketchy evidence of past links between field reversals and species extinctions. ---
**Author:** ![Ike\_Witt](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ike_witt/32/283_2.png) [@Ike\_Witt](https://boards.straightdope.com/u/Ike_Witt)\ **Post date:** [July 13, 2004, 12:21pm UTC](https://boards.straightdope.com/t/how-is-the-earths-magnetic-field-flipping-going-to-knock-out-the-us-power-grid/254852/10 "2004-07-13T12:21:42Z")
> [@Thaumaturge](#): > > The feild doesn’t switch all at once. Small regions of the earth’s surface have already experienced the switch IIRC, mainly in Africa. I don’t suppose that you have a cite for this? ---
**Author:** ![antechinus](https://avatars.discourse-cdn.com/v4/letter/a/fbc32d/32.png) [@antechinus](https://boards.straightdope.com/u/antechinus)\ **Post date:** [July 13, 2004, 12:34pm UTC](https://boards.straightdope.com/t/how-is-the-earths-magnetic-field-flipping-going-to-knock-out-the-us-power-grid/254852/11 "2004-07-13T12:34:36Z")
Bugger the grids, _if_ the flip stalled wouldn’t the solar wind blow away Earths atmosphere. ---
**Author:** ![Musicat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/musicat/32/20189_2.png) [@Musicat](https://boards.straightdope.com/u/Musicat)\ **Post date:** [July 13, 2004, 1:16pm UTC](https://boards.straightdope.com/t/how-is-the-earths-magnetic-field-flipping-going-to-knock-out-the-us-power-grid/254852/12 "2004-07-13T13:16:02Z")
Regarding the effect of a magnetic pole shift on navigation by animals, it would seem, as **Q.E.D.** said, that they can adapt. I imagine that would be possible for a gradual shift, but how about a swift shift? And how swift would it have to be? (And I believe animals that use magnetic data have alternate forms of navigation that might be relied on more if needed.) It seems to me that if the effects are as devastating as the NYT article suggests, that we would see a close correlation between species extinction and pole shifts. Or perhaps species evolution – maybe the “punctuated equilibrium” theory could use this as a mechanism. What degree of correlation has been documented? ---
**Author:** ![Colophon](https://avatars.discourse-cdn.com/v4/letter/c/f05b48/32.png) [@Colophon](https://boards.straightdope.com/u/Colophon)\ **Post date:** [July 13, 2004, 1:37pm UTC](https://boards.straightdope.com/t/how-is-the-earths-magnetic-field-flipping-going-to-knock-out-the-us-power-grid/254852/13 "2004-07-13T13:37:22Z")
If the magnetic field essentially drops to zero between reversals, what are the implications for cosmic radiation reaching the Earth’s surface. Doesn’t the magnetic field shield us from this? And **Thaumaturge** , what do you mean by “Small regions of the earth’s surface have already experienced the switch IIRC, mainly in Africa.”? Got cites? ---
**Author:** ![brane\_damaj](https://avatars.discourse-cdn.com/v4/letter/b/a587f6/32.png) [@brane\_damaj](https://boards.straightdope.com/u/brane_damaj)\ **Post date:** [July 13, 2004, 1:37pm UTC](https://boards.straightdope.com/t/how-is-the-earths-magnetic-field-flipping-going-to-knock-out-the-us-power-grid/254852/14 "2004-07-13T13:37:43Z")
> [@antechinus](#): > > Bugger the grids, _if_ the flip stalled wouldn’t the solar wind blow away Earths atmosphere. Uh…no. The solar “wind” is not exactly the hurricane force you’re invisioning. It is merely a very dispersed stream of charged particles (mostly hydrogen). As such, it has minimal kinetic force. After all, the satellites and probes we send around the solar system don’t blow away. Our gravity is much more than a match than a few pitiful hydrogen particles. Venus, incidentally, is much closer to the sun, has weaker gravity, and a much thicker atmosphere. While I can’t speak to Venus’s magnetic field, it seems logical that it too would wax and wane like Earth’s, and yet it still retains its thick air. ---
**Author:** ![brane\_damaj](https://avatars.discourse-cdn.com/v4/letter/b/a587f6/32.png) [@brane\_damaj](https://boards.straightdope.com/u/brane_damaj)\ **Post date:** [July 13, 2004, 1:50pm UTC](https://boards.straightdope.com/t/how-is-the-earths-magnetic-field-flipping-going-to-knock-out-the-us-power-grid/254852/15 "2004-07-13T13:50:17Z")
> [@Colophon](#): > > If the magnetic field essentially drops to zero between reversals, what are the implications for cosmic radiation reaching the Earth’s surface. Doesn’t the magnetic field shield us from this? Yeah, but the atmosphere itself helps scatter it. There would likely be more skin cancer and such, but overall we’d be OK. It would hardly sterilize the Earth. I read a theory a while back that tried to link magnetic reversals to explosions of new species, the theory being that the increased radiation caused more mutations, and therefore kick-started evolution a bit. I don’t know how plausible that is, but there you go. ---
**Author:** ![Futile\_Gesture](https://avatars.discourse-cdn.com/v4/letter/f/f05b48/32.png) [@Futile\_Gesture](https://boards.straightdope.com/u/Futile_Gesture)\ **Post date:** [July 13, 2004, 2:04pm UTC](https://boards.straightdope.com/t/how-is-the-earths-magnetic-field-flipping-going-to-knock-out-the-us-power-grid/254852/16 "2004-07-13T14:04:17Z")
> [@Thaumaturge](#): > > The feild doesn’t switch all at once. Small regions of the earth’s surface have already experienced the switch IIRC, mainly in Africa. True. Africa’s magnetic field is totally third world. Give to charity so that they can build a better one. :rolleyes: Unless Africa has found a way of inhabiting a completely different planet there is no way it, or any other small region (including the US power grid), can have switched to a different magnetic field from the rest of us. ---
**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\ **Post date:** [July 13, 2004, 2:20pm UTC](https://boards.straightdope.com/t/how-is-the-earths-magnetic-field-flipping-going-to-knock-out-the-us-power-grid/254852/17 "2004-07-13T14:20:32Z")
> [@brane damaj](#): > > > [@antechinus](#): > > > > wouldn’t the solar wind blow away Earths atmosphere. > > Uh…no. > > The solar “wind” is not exactly the hurricane force you’re invisioning. Actually, the magnetic field _does_ limit erosion of earth’s atmosphere by the solar wind. As the magnetic field decreases, more charged ions from the sun hit the atmosphere, heating and expanding it. The effect is small. On non-magnetic Mars for example, it’s thought that it took [several billion years for the solar wind to strip the atmosphere.](http://science.nasa.gov/headlines/y2001/ast31jan_1.htm). A few thousand years with a minimal field will have little effect on earth. However, without a magnetic shield, the earth’s atmosphere _will_ typically extend further into space than we are used to, and this will pose [problems for satellites in low earth orbit.](http://science.nasa.gov/headlines/y2000/ast30may_1m.htm) ---
**Author:** ![David\_Simmons](https://avatars.discourse-cdn.com/v4/letter/d/9de053/32.png) [@David\_Simmons](https://boards.straightdope.com/u/David_Simmons)\ **Post date:** [July 13, 2004, 2:53pm UTC](https://boards.straightdope.com/t/how-is-the-earths-magnetic-field-flipping-going-to-knock-out-the-us-power-grid/254852/18 "2004-07-13T14:53:29Z")
> [@Colophon](#): > > If the magnetic field essentially drops to zero between reversals, what are the implications for cosmic radiation reaching the Earth’s surface. Doesn’t the magnetic field shield us from this? > > And **Thaumaturge** , what do you mean by “Small regions of the earth’s surface have already experienced the switch IIRC, mainly in Africa.”? Got cites? It isn’t certain by any means that the magnetic field drops to zero. The field is presumed to be caused by fluid motion in the earth’s core. Those motions will continue and will still result in a dynamo effect resulting in a magnetic field but it will not be as organized as it is now. It apparently, based on history, will then be reorganized with the dipole field reversed for some reason that is currently a mystery. What I’m saying is that the field consists of a main, dipole, field having a dominant north-south pole pair plus many subsidiary fields have two pairs, three pairs, four pairs of poles, etc. The current weakening of the dipole field is accompanied by an apparent transfer of the field energy to the other component fields having a greater number of poles. The total overall field remains about the same. (Source: An article by Prof. Stephen G. Bruch, University of Maryland in the book _Scientists Confront Creationism_, W.W. Norton Co.) Prof. Brush writes: “McDonald and Kunst (_Journal of Geophysical Research_ No. 73) state explicity that 'the magnetic dipole field is being driven … to smaller values by fluid motions which **transform it magnetic energy into that of nearby neighboring modes rather than expend it more directly as Joule heat.’** In other words, the energy is being transferred to from the dipole field to the quadrpole field and to higher moments rather than being dissipated as heat. This implies that the value of the dipole field … is limited by the total magnetic energy **which does not change very rapidly.** ” ---
**Author:** ![tygerbryght](https://avatars.discourse-cdn.com/v4/letter/t/a9a28c/32.png) [@tygerbryght](https://boards.straightdope.com/u/tygerbryght)\ **Post date:** [July 13, 2004, 3:51pm UTC](https://boards.straightdope.com/t/how-is-the-earths-magnetic-field-flipping-going-to-knock-out-the-us-power-grid/254852/19 "2004-07-13T15:51:46Z")
> [@Squink](#): > > Actually, the magnetic field _does_ limit erosion of earth’s atmosphere by the solar wind. As the magnetic field decreases, more charged ions from the sun hit the atmosphere, heating and expanding it. Possibly dumb question: What is the relationship between the magnetosphere and the Van Allen Belts, please? ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [July 13, 2004, 4:17pm UTC](https://boards.straightdope.com/t/how-is-the-earths-magnetic-field-flipping-going-to-knock-out-the-us-power-grid/254852/20 "2004-07-13T16:17:14Z")
> [@tygerbryght](#): > > What is the relationship between the magnetosphere and the Van Allen Belts, please? The Van Allend radiation belts are composed of charged particls, mainly fromt eh solar wind, trapped by the Earth’s magnetosphere. From [here](http://www.portaljuice.com/van_allen_radiation_belt.html): > [@](#): > > It is generally understood that the Van Allen belts are a result of the collision of Earth’s magnetic field with the solar wind. Radiation from the solar wind then becomes trapped within the magnetosphere. The trapped particles are repelled from regions of stronger magnetic field, where field lines converge. This causes the particle to bounce back or “mirror.” [Next page](https://boards.straightdope.com/t/how-is-the-earths-magnetic-field-flipping-going-to-knock-out-the-us-power-grid/254852.md?page=2)