MAP: Past and present locations of the NMP.

The North Geographic Pole (True North) represents the top of the Earth's fixed "axis" upon which it spins, but the North Magnetic Pole (NMP) - the point that traditional magnetic compasses point toward - is at a different location.

Not only is the NMP at a different location, it is constantly moving! As magnetic compasses point to the NMP (not True North), it is important to know where that pole is - and keep track of it.

Because of its importance to navigation, finding its location was a major objective of the British Royal Navy in the 19th century. The Navy was very interested in magnetism and included magnetic observers on many of its Arctic expeditions. Great rewards were offered to whoever found it's exact location.

When James Clark Ross discovered the location of the NMP on June 1, 1831, it was on the west coast of Boothia Peninsula (70° 05.3' N, 96° 46' W).

Ross calculated a magnetic inclination (angle at which the magnetic forces enter the Earth) of 89° 59'. As fluctuations in the magnetic field cause the NMP to be continually moving in an irregular path around its average position, and given the accuracy of his instruments, this reading was close enough to 90° for him to claim to be on top of the Pole.

Since that discovery in 1831, the NMP has moved about 1100 km / 684 miles. It also started to accelerate - it's now moving at more than 40 km / 25 miles per year.

If the NMP maintains its present speed and direction - it could reach Siberia in about 50 years.