Geographic North Pole and North Magnetic Pole

Not that it will change my life for ever, but I happened to wonder how far away the Geographic North Pole and the Magnetic North Pole are from each other.

I used Google Earth to get an approximation of the distance. I used the ruler (menu Tools > Ruler in the version 4.2.0198.2451 (beta) of Google Earth).

The measurement is 814.5 kilometers between the North Magnetic Pole and the Geographic North Pole. I ignore whether the number of kilometers is the true angular distance on the spheric surface or just a flat 2D distance.

A latitude of 90º North determines the geographic north pole. The point at which the Earth’s magnetic field points vertically downwards (i.e. the “dip” is 90°) is the North Magnetic Pole. It was at 82.7° N 114.4° W in 2005. In the screen capture from Google Earth. The dot on the left in the magnetic pole and the one on the right, the geographic one.

The magnetic poles move all the time. This movement is due to the bombardment of charged particles from the Sun and because the core magnetic field changes with time. The north dip pole moves at to up to 60 kilometers per year and the south at less than 20 kilometers per year. There is a recorded historic drift that has triggered scientific speculation about whether the pole moving towards Siberia.

The magnetic poles are not diametrically opposed. The field morphology is different in the north and south hemispheres.

This is the Google Earth file containing the coordinates of the two poles: north poless kmz

This animation shows the surface position of the north dip pole as a moving black dot:

Source: http://www.agu.org/eos_elec/2007/29-293.html