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Geomagnetic Field Reversal

  1. Jul 25, 2005 #1
    Without pulling out the paper I wrote 10 some years ago discussing the geomagnetic field reversal, I would like to know what current data analysis agrees on about the following:
    From journals, Nature and Science back as many years ago, I found the science community speculating that at the time of a reversal, GFR, things on the planet changed, such as the emergence of man, the disappearance of certain creatures.
    In other words signifigant events in world history.
    Is this still a belief of leading researchers?

    Thank you,
    Suzanne Elizabeth Seitz

    Also posted in Astronomy & Cosmology section.
     
    Last edited: Jul 25, 2005
  2. jcsd
  3. Jul 25, 2005 #2
    Ive looked this up and no link seems to exist.

    Humanoid life has not been influenced by the last mafnetic reversal for as far as is presently known.
     
  4. Jul 25, 2005 #3

    Thank you.

    Since you looked it up, when was the last GFR?
    And did it say when we are due for another?
    Please.

    S
     
  5. Jul 26, 2005 #4
    I think statistically we are overdue for another reversal, but I'm not sure about this. I don't have a link though, I remember my geology lecturer presenting some data when I was studying this 6 months ago.

    The last field reversal was 780,000 years ago, beginning the Brunhes Normal Chron. That was preceeded by the Matuyama Reverse Chron which began 2.5million years ago. There have been at least 12 magnetic reversals in the last 4 million years, as each chron (a period where the magnetic field is predominantely in one direction) is interspersed with short periods of the opposite field direction. From memory the Matuyama Chron had 3 or 4 of these, but we haven't had one during the Brunhes.
     
  6. Jul 26, 2005 #5
    Considering that there have been super-chrons of tens of millions years, statistics have no meaning I'd say. To be more precieze the last chrons are: Brunhes -0.789 Mya- Matuyama - 2.581 Mya - Gauss - 3.58 Mya - Gilbert

    Although Brunhes has no subchrons, there have been many more geomagnetic excursions, a collapse of the magnetic field, hardly known of the orther chrons, There is mild dispute whether those excursions are related to ice age climate and or cosmogenic radioactivity.

    This guy says yes,
    but this one says no.
     
  7. Jul 26, 2005 #6
    Thank you to all.

    This has been very valuble to me and am already making my way back into this area if investigation.

    S
     
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