[custom_adv] The South Pole, also known as the Geographic South Pole or Terrestrial South Pole, is one of the two points where the Earth's axis of rotation intersects its surface. [custom_adv] It is the southernmost point on the surface of the Earth and lies on the opposite side of the Earth from the North Pole. [custom_adv] Situated on the continent of Antarctica, it is the site of the United States Amundsen–Scott South Pole Station, which was established in 1956 and has been permanently staffed since that year. [custom_adv] The Geographic South Pole is distinct from the South Magnetic Pole, the position of which is defined based on the Earth's magnetic field. The South Pole is at the center of the Southern Hemisphere. [custom_adv] For most purposes, the Geographic South Pole is defined as the southern point of the two points where the Earth's axis of rotation intersects its surface (the other being the Geographic North Pole). [custom_adv] However, the Earth's axis of rotation is actually subject to very small "wobbles" (polar motion), so this definition is not adequate for very precise work. [custom_adv] The geographic coordinates of the South Pole are usually given simply as 90°S, since its longitude is geometrically undefined and irrelevant. When a longitude is desired, it may be given as 0°. [custom_adv] At the South Pole, all directions face north. For this reason, directions at the Pole are given relative to "grid north", which points northwards along the prime meridian. [custom_adv] The Geographic South Pole is located on the continent of Antarctica (although this has not been the case for all of Earth's history because of continental drift). [custom_adv] It sits atop a featureless, barren, windswept and icy plateau at an altitude of 2,835 metres (9,301 ft) above sea level, and is located about 1,300 km (800 mi) from the nearest open sea at Bay of Whales. [custom_adv] The polar ice sheet is moving at a rate of roughly 10 metres per year in a direction between 37° and 40° west of grid north, down towards the Weddell Sea. [custom_adv] The Geographic South Pole is marked by a stake in the ice alongside a small sign; these are repositioned each year in a ceremony on New Year's Day to compensate for the movement of the ice.