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Deep-sea sediment records of the Laschamp geomagnetic field excursion (41kya)

  1. Jan 14, 2010 #1
    This paper Deep-sea sediment records of the Laschamp geomagnetic field excursion (∼41,000 calendar years before present) concludes that the narrow Laschamps excursion event, or class I excursions in general, are more closely related to normal secular variation and are not necessarily a prelude to magnetic field reversal. So what are they and what causes them? The geomagnetic field suffered for some time and so one would imagine that life did as well: "magnetic field intensities less than 10% of normal that persisted for almost 2000 years". How relevant is this event to the megafaunal extinctions for example?
    Wikipedia Geomagnetic Excursions
    Wikipedia Earth's Magnetic Field

    Last edited by a moderator: May 9, 2012
  2. jcsd
  3. Jan 14, 2010 #2


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    We should not be bothering with alleged relevance to megafaunal extinctions unless that association appears somewhere in the scientific literature, and I am pretty confident it doesn't.

    Discussion of the ideas in the paper, which are to do with physical causes of magnetic field excursions, are fine.

    Cheers -- sylas
  4. Jan 14, 2010 #3
    Okay, but I'm interested in the effects of a 10% magnetic field for 2000 years on the plant and animal life. I'll google some more papers I guess..
  5. Jan 15, 2010 #4
    Am I allowed to speculate on a 'Rogue Moon' hypothesis (or any 0.5 moon object), whose flyby exerted a gravitational influence which disrupted the dynamics of the Earth's core some 41,000 years ago?
  6. Jan 15, 2010 #5


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    Check the Guidelines. Speculations about a rogue moon would be against this section, because they have not been published in the scientific literature (and never will be, frankly).
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