Does the “N” on a compass needle point to the North Pole?

The North and South Poles represent the two ends of the axis around which the Earth rotates. Compasses actually point to “magnetic north” (in the Northern Hemisphere). Magnetic north is determined by two opposing forces within the Earth itself: the solid inner core and the outer core of molten iron, both of which generate a magnetic field. The chaotic interplay of these forces means that the position of magnetic north is constantly shifting (currently at a rate of about 35 miles per year) and is currently located in Northern Canada.

If compass needles don’t exactly point at the North Pole, how have they been used for navigation for thousands of years? Because it’s reasonably close. But, the difference between true north and magnetic north could grow large enough to cause problems, particularly for migratory birds that rely on the Earth’s gravitational field.

A bigger issue may be magnetic pole reversal, which happens every few hundred thousand years and scientists believe may be in the process of happening again. Earth’s magnetic field has been growing steadily weaker for about two thousand years – a precursor to pole shift, in which the north and south magnetic poles actually switch. The switching process itself takes an estimated one thousand to ten thousand years, during which time the strength of the Earth’s magnetic field drops to nearly zero!