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Earths magnetic field

  1. Feb 27, 2004 #1
    I heard that the earths magnetic field changes every few thousands of years? is this true, if it is how does that happen
  2. jcsd
  3. Feb 27, 2004 #2
    The earth's magnetic poles are in constant motion, moving in distances easily measured in just a year. This is the reason why magnetic compasses readings must be recalibrated over time.

    I believe the best answer available today is that this is caused by some sort of shifting of the iron inside of earth.
  4. Feb 27, 2004 #3


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    There is indeed geological evidence that the earth's magnetic field reverses periodically. The cause for the reversal is not really understood, neither the cause for the field itself. There is a thread about ithere .

    The thread is largely based on the work of Dr. Daniel Lathrop of University of Maryland.http://complex.umd.edu/dynamo/index.html [Broken].
    Last edited by a moderator: May 1, 2017
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