Re: Earth's Magnetic Field

[William Beaty <billb@ESKIMO.COM>]

On Tue, 11 May 1999, Chuck Britton wrote:

> And it is a surprisingly SHORT 'bar' magnet that models the shape of
> the earth's field.

I was suprised to learn that the spots on the Earth's surface which have
the strongest fields are not at the poles.  This was from a field map I
found in a geophysics book.  The Earth's field can be modeled as a
dipole plus a quadrupole plus many higher orders of pole-patterns, with
the dipole being the strongest.  That quadrupole messes things up: the
strong spots in the northern hemisphere are in Siberia and Canada, while
the northern (Canadian!) magnetic pole is on an (isomag?) line which
swerves down and crosses the state of Virginia.

In the southern hemisphere things are more sensible, with a magnetic
hot-spot quite near the location of the magnetic pole.  Quite near =
couple of hundred KM.

((((((((((((((((((((( ( (  (   (    (O)    )   )  ) ) )))))))))))))))))))))
William J. Beaty                                  SCIENCE HOBBYIST website
billb@eskimo.com                                  http://www.amasci.com
EE/programmer/sci-exhibits          science projects, tesla, weird science
Seattle, WA   206-781-3320          freenrg-L taoshum-L vortex-L webhead-L