Talk:Pillar of Prophecy/@comment-98.237.90.87-20121215051212/@comment-5225231-20121216014304

A little background:

There are three poles: 1) spin axis, 2) geomagnetic, and 3)Magnetic.

Very simplified here; When people think of the Earth's magnetic field, a bar magnet comes to mind. However, that is simplified view that works pretty well but is not technically accurate.

Magnetic pole - lines of force are virtical to the Earth's surface. there are more than one each with its own intensity.

Geomagnetic pole - Summing the above magnetic poles gives us the geomagnetic pole which approximates the simplified dipole we usually use.

For the rest of this post I will stick with the simplified geomagnetic pole model.

Spin axis pole - the spin axis of the earth (equatorial plane) which is tilted 23.5 degrees from the Earth's orbit plane (ecliptic plane)

Due to convection currents in the internal magma the geomagnetic pole wanders. There is also a periodic reversal of the magnetic polarity with an average of 450,000 years. This reversal is basically a weakening of the pole and then it restores but with an opposite polarity. We see this same phenomena in the Sun only on a much faster scale. Note: the time between reversals varies.

Since pole reversals do not coincide with mass extinction events, it appears that the pole reversals will not cause the disasters people predict. Also since a pole shift takes roughly 1000 years, not something anyone of us will see in our lifetime.

Fun fact: since the magnetic field is offset from the spin axis, the Van Allen belts are pulled in towards the earth just east of South America creating the South Atlantic Anomaly.

Sorry for any grammar or spelling errors since this was posted from an iPad.