Magnetic Pole Wandering
Country: United States
Date: April 2006
Why do the magnetic poles change location from
time to time and how much? Is there a certain range of their
movement and how is that range measured? in degrees? Also, I
assume magnetic north points towards the magnetic pole. What is
geodetic north based on? Thank you for your time.
The details of the answers to both your questions I do not believe
are fully understood. It is proposed that the magnetic north pole
wanders as a result of convection of molten iron in the earth's
mantle, but what drives that is open to debate. The geodetic pole,
the axis of rotation also follows a complex path. It is influenced
by gravitational interactions of the Sun, Moon, and other planets,
tidal lag, and other "minor" effects. If I remember correctly there
are some 10-12 effects that cause the Earth's geodetic north to
wander, one of which is the migration of the magnetic north pole!
Gets to be very complicated.
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