The North Pole, also known as the Geographic North Pole or Terrestrial North Pole, is, subject to the caveats explained below, defined as the point in the northern hemisphere where the Earth's axis of rotation meets the Earth's surface. It should not be confused with the North Magnetic Pole.

The North Pole is the northernmost point on Earth, lying diametrically opposite the South Pole. It defines latitude 90° North, as well as the direction of True North. At the North Pole all directions point south.

While the South Pole lies on a continental land mass, the North Pole is located in the middle of the Arctic Ocean, amidst waters that are almost permanently covered with constantly shifting sea ice. This makes it impossible to construct a permanent station at the North Pole (unlike the South Pole). However, the Soviet Union, and later Russia, have constructed a number of manned drifting stations, some of which have passed over or very close to the Pole. Recently, scientists have predicted that the North Pole may become seasonally ice-free by 2050 due to Arctic shrinkage. More pessimistically, it was claimed by some scientists that the Arctic ice-cap might temporarily disappear in mid 2008, a prediction which did not come to pass.

The sea depth at the North Pole has been measured at 4,261 metres (13,980 ft). The nearest land is usually said to be Kaffeklubben Island, off the northern coast of Greenland about 440 miles (c. 700 km) away, though some perhaps non-permanent gravel banks lie slightly further north.

Precise definition

See also: Polar motion.

The Earth's axis of rotation – and hence the position of the North Pole – was commonly believed to be fixed (relative to the surface of the Earth) until, in the 18th century, the mathematician Leonhard Euler predicted that the axis might "wobble" slightly. Around the beginning of the 20th century astronomers noticed a small apparent "variation of latitude", as determined for a fixed point on Earth from the observation of stars. Part of this variation could be attributed to a wandering of the Pole across the Earth's surface, by a range of a few meters. The wandering has several periodic components and an irregular component. The component with a period of about 435 days is identified with the 8 month wandering predicted by Euler and is now called the Chandler wobble after its discoverer. This "wobble" means that a (fixed) definition of the Pole based on the axis of rotation is not useful when metre-scale precision is required.

It is desirable to tie the system of Earth coordinates (latitude, longitude, and elevations or orography) to fixed landforms. Of course, given continental drift and the rising and falling of land due to volcanoes, erosion and so on, there is no system in which all geographic features are fixed. Yet the International Earth Rotation and Reference Systems Service and the International Astronomical Union have defined a framework called the International Terrestrial Reference System. The North Pole of this system now defines geographic North for precision work, and it does not quite coincide with the rotation axis.