18. There is more than one north pole – True (or geodetic) north is a fixed point, located where the Earth’s axis of rotation meets the planet’s surface, diametrically opposite the south pole. However if you look at a compass needle, it doesn’t point to the north pole, but rather to a place a few hundred kilometres south-east: magnetic north. Earth acts like a giant magnet, and the magnetic north is one of its poles. The planet’s magnetic field is created by churning molten iron in the planet’s outer core.
As these currents change, so does the location of the magnetic north pole, which is currently wandering at a speed of about 55 kilometres (34 miles) a year. After drifting through northern Canada, magnetic north is now heading towards Siberia. More dramatic changes could, however, be afoot. In the past, Earth’s magnetic poles have switched places every 500,000 years. The reason behind these flips is unknown, but geophysicists predict that the next one could be coming up in a few thousand years.
