[Iron Munro]

Another item of interest: North Magnetic Pole Moving Due to Core Flux

Also, consider this: Earth Magnetic Field Reversal

"Scientists have been observing changes in the direction of earth's magnetic field which took place recently as well as in the distant past. NASA’s website features a map showing the gradual northward migration of the north magnetic pole in the past century and a half.

See: Earth's Inconstant Magnetic Field

Since more than double the time interval has elapsed since the last reversal, compared to the time lapse between the previous two pole reversals, some believe we may be overdue for the next north-south flip. However, though the interval between reversals of the Earth’s magnetic field can be as short as 5,000 years, it can also be as long as 50 million years. There does not seem to be any logic or rule governing the planet’s behavior."

[Errant]

I like their chart of the magnetic pole changes.

[Errant]

One has to ask why the changes... If the magnetic field is generated by the spin of the inner core then does this mean it's spin alignment with the rotation of the earth's crust and mantle is changing? If so, what are the effects and why now?

Imagine the spin of a solid iron ball becoming erratic and this iron ball which is hundreds of miles in diameter starts bouncing around from mantle to mantel under the Earth's crust and our feet. :)