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Geomagnetic reversal and pole shift

  1. Jul 8, 2009 #1
    im having a hard time finding any reputable information or scientific backing to support the theory that our magnetic field will reverse and/or shift anytime soon. also would this mean that the equator areas would remain almost the same as before in terms of magnetic field?
     
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  3. Jul 8, 2009 #2

    Evo

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  4. Jul 8, 2009 #3

    negitron

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    There is, in fact, compelling evidence that we are seeing the beginning of just such a reversal now.

    http://scienceblogs.com/highlyallochthonous/2009/02/is_the_earths_magnetic_field_a.php [Broken]
     
    Last edited by a moderator: May 4, 2017
  5. Jul 8, 2009 #4
    i know that it has happened many times and people speculate we are "overdue" but since the numbers of years between are so large (in the hundred thousands) combined with the fact that the times between reversals vary a great deal, probabilities that it will happen in our life time dont seem any higher than maybe in a thousand years (if average stable times are your basis) i would like to know other things that increase the probability such as the magnetic field weakening, because with the limited resources i have to make a decision it just seems as though the probabilities of it happening within a hundred years arent any higher than say a thousand.
     
  6. Jul 8, 2009 #5
    and maybe some insight involving the sun
     
  7. Jul 8, 2009 #6

    Evo

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    Did you read the transcript? Sounds like your questions are answered in there. And if you aren't into reading, there are nifty graphics that you can click on.
     
  8. Jul 8, 2009 #7

    negitron

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    Astoundingly unlikely occurrences do happen, however. Geologically speaking, we are at the one instant in time when the Moon appears nearly exactly the same angular size as the Sun, leading to what must surely be among the rarest of sights in the whole Universe: a total annular eclipse.
     
  9. Jul 8, 2009 #8
    i did read it and it is apparent it will happen soon, however the decreasing field may very well decrease and increase and decrease and increase until ultimately resulting in a geomagnetic reversal, there is nothing to say that this is the final field decreasing period that leads to the reversal, but we are obviously close to one. actually i was originally questioning the basis on the multiple theories and stories ive come across saying it will happen definitely around 2012-2030 without providing any true evidence or reputable sources. But thanks to these excellent sources you all have given me i have made my conclusion that it WILL happen soon but not in any DEFINITE small time period. oh yeah and that decent sources are becoming harder and harder to find due to the massive amount of rubbish flooding the internet!
     
  10. Jul 8, 2009 #9

    Evo

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    Ah, you are referring to 2012 nonsense, it is just that...nonsense. You are absolutely right about those kinds of predictions.
     
  11. Jul 9, 2009 #10
    Yes, what is soon?

    The current decrease in field strenght doesn't signify anything, or like the owner of this webpage uses to say: the Earth magnetic field has never been so strong in million years, what else would you expect it to do, except going down? Note that there is a goldmine of geomagnetic publications on that page. This one is especially interesting, a comprehensive compilation of geomagnetic variation during the last 800,000 years.

    hur586.gif

    So the field goes up and down seemingly at random. Sometimes the field collapses, a "paleomagnetic excursion" (PME), in some irregular semi cycle of about 80-100,000 years. The last one, the Laschamps PME was 40,000 years ago(*), not a reason to assume that we are due anytime soon. Also the real magnetic field reversals are not a common event. Althought during the last geologic period, the Czenozonic, it has semi cycles of several 100,000 years, the last one the Brunhes Matuyama event, happened 778,000 years ago, but there have also been "super chrons" of many million years.

    You can also see why Langereis did that assessment about what-goes-up-must-come-down in the last thousand years. And finally; neither climate nor any catastrophic events are linked to any variation in the Earth magnetic field and the message is: don't worry, nothing is going on here.

    (*) Edit: Note: at some places a more recent PME has been recorded at 25,000 years ago, the Mono Lake PME, however this was not on a global scale. Also an apparent field reversal at 10,000 years, the alleged Goteburg flip, was not reproduceable anywhere and it is assessed to be erratic.
     
    Last edited: Jul 9, 2009
  12. Jul 9, 2009 #11
    One of my senior lecturers viewed everything post Cambrian as superficial drift deposits. On that basis the reversal is due immediately, within the next half million years.
     
  13. Jul 9, 2009 #12

    LURCH

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    Funny you should mention that. I arrived at the theory (on my own; always shaky scientific ground) that the Sun might play a role in polar reversals. it seemed to me that, as the earth's magnetic field becoes more and more unstable and disorganised, the Sun's own polar reversal (once every 11yrs or so) could trigger the flip.

    I contacted http://complex.umd.edu/dynamo/index.html" [Broken], and he informed me that the flips appear to take thousands of years, so the Sun's 11yr cycle really doesn't fit the profile.
     
    Last edited by a moderator: May 4, 2017
  14. Jul 13, 2009 #13
     
    Last edited by a moderator: May 4, 2017
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