North Pole Defining North Poles In Astronomy Defining The North

A North Pole is the northernmost point on any planet. There are various ways of defining a planet's North Pole. Earth's Pole, however it is defined, lies in the Arctic Ocean.

1 Defining North Poles in astronomy

The axial tilt of the planet Uranus is very nearly 90 degrees relative to the ecliptic plane, so that labelling one pole or the other to be the "north" pole is still a matter of some dispute. When a body's axial tilt is greater than 90 degrees, either one of two interpretations can be considered equally valid; the axis could be tilted greater than 90 degrees, or the labelling of the poles could be reversed (north becomes south) and the body considered to be rotating in a retrograde direction.

Some bodies in the solar system, including Saturn's moon Hyperion and the asteroid Toutatis, lack a geographic north pole. They rotate chaotically because of their irregular shape and gravitational influences from nearby planets and moons.

The projection of a planet's north geographic pole onto the celestial sphere gives its north celestial poleThe two celestial poles are the imaginary points where the Earth's spin axis intersects the celestial sphere. The sky appears to drift overhead from east to west, completing a full circuit around the sky in 24 ( sidereal) hours. This phenomenon is due to.

2 Defining the North Pole of Earth

The North Pole, the northNorth is one of the four primary cardinal directions, specifically the direction treated, in Western culture, as the primary direction and used (explicitly or implicitly) to define all other directions. As to the arbitrary nature of this choice, and psychernmost point on the EarthEarth also known as the Earth or Terra is the planet on which we live, the third planet outward from the Sun. It is the largest of the solar system's terrestrial planets, and the only planetary body that modern science confirms as harbouring life. The pla, can be defined in four different ways. Only the first two definitions are commonly used. However it is defined, the North Pole lies in the Arctic Ocean.

3 Geographic North Pole

The Geographic North Pole, also known as True North, is the northern point at which the Earth's axis of rotation meets the surface. Geographic North has a known fixed position, at latitudeLatitude denoted φ, gives the location of a place on Earth north or south of the Equator. Latitude is an angular measurement ranging from 0° at the Equator to 90° at the poles. Usually, the difference in latitude largely affects the climate and/or wea 90° North. In whichever direction you travel from here, you are always heading south.

The boundaries of CanadaCanada historically the Dominion of Canada is the second-largest, and northernmost, country in the world. It is a decentralized federation of 10 provinces and 3 territories, governed as a constitutional monarchy, and formed in 1867 through an act of Confe extend all the way to the Geographic North Pole. There is no land at this location, which is usually covered by sea ice. There are in fact 770 km of ocean between the pole and Canada's northernmost point. Nevertheless, the North Pole of the Earth may be said to be located in Canada. However, recently, Russia and Denmark are poised to contest this point. In the mid-20th Century, Canada made an official claim to the pole; if no compelling opposition is presented by the mid-21st Century, the pole will officially be considered part of Canada.

The first expedition to the pole is generally accepted to have been made by Navy engineer Robert Edwin Peary and his employee, black American Matthew Henson and four Inuit men ( Ootah , Seegloo, Egingway , and Ooqueah ) on April 6, 1909. Polar historians believe that Peary honestly thought he had reached the pole. However a 1996 analysis of a newly-discovered copy of Peary's record indicates that Peary must have been in fact 20 miles (32km) short of the Pole.

The first undisputed sight of the pole was in 1926 by Norwegian explorer Roald Amundsen and his American sponsor Lincoln Ellsworth from the airship Norge, designed and piloted by the Italian Umberto Nobile, in a flight from Svalbard to Alaska.

On May 3, 1952 U.S. Air Force Lieutenant Colonel Joseph O. Fletcher and Lieutenant William P. Benedict landed a plane at the geographic North Pole.

On April 6, 1992 Robert Schumann became the youngest person to visit the north pole.

In popular mythology, Santa Claus resides at the geographic North Pole.

4 Magnetic North

Magnetic North is one of several locations on the Earth's surface known as the "North Pole". Its definition, as the point where the geo magnetic field points vertically downwards, i.e. the dip is 90°, was proposed in 1600 by Sir William Gilbert, a courtier of Queen Elizabeth I, and is still used. It should not be confused with the less frequently used Geomagnetic North Pole. Magnetic North is the place to which all magnetic compasses point, although since the pole marked "N" on a bar magnet points north, and only opposite magnetic poles are attracted to each other, the Earth's magnetic north is actually a south magnetic pole.

Magnetic poles can flip flop from north to south and back again. The Earth's poles have done this repeatedly throughout history, and 500,000 years ago, the south magnetic pole was at the North Pole. It is thought that this occurs when the circulation of liquid nickel/ iron in the Earth's outer core is disrupted and then reestablishes itself in the opposite direction. It is not known what causes these disruptions.

The first expedition to reach this pole was led by James Clark Ross, who found it at Cape Adelaide on the Boothia Peninsula on June 1, 1831. Roald Amundsen found Magnetic North in a slightly different location in 1903. The third observation of Magnetic North was by Canadian government scientists Paul Serson and Jack Clark, of the Dominion Astrophysical Observatory, who found the pole at Allen Lake on Prince of Wales Island. The Canadian government has made several measurements since, which show that Magnetic North is continually moving northwest. Its location (in 2003) is 78°18' North, 104° West, near Ellef Ringness Island , one of the Queen Elizabeth Islands, in Canada. During the 20th century it has moved 1100 km, and since 1970 its rate of motion has accelerated from 9 km/ a to 41 km/a ( 2001- 2003 average; see also Polar drift). If it maintains its present speed and direction it will reach Siberia in about 50 years, but it is expected to veer from its present course and slow down.

This movement is on top of a daily or diurnal variation in which Magnetic North describes a rough ellipse, with a maximum deviation of 80 km from its mean position. This effect is due to disturbances of the geomagnetic field by the sun. A line drawn from one magnetic pole to the other does not go through the centre of the Earth, it actually misses it by about 530 km.

The angular difference between Magnetic North and true North varies with location, and is called the magnetic declination.

5 Geomagnetic North Pole

The Geomagnetic North Pole is the pole of the Earth's geo magnetic field closest to true north.

Like the Magnetic North Pole, it is a south magnetic pole, because it attracts the north pole of a bar magnet. It is the centre of the region in the magnetosphere in which the Aurora Borealis can be seen. Its present location is 78°30' North, 69° West, near Thule in Greenland.

The first voyage to this pole was by David Hempleman-Adams in 1992.

6 The Northern Pole of Inaccessibility

The Northern Pole of Inaccessibility, located at 84°03' north, 174°51' west, is the point farthest from any northern coastline, about 1100 km from the nearest coast. It is a geographic construct, not an actual physical phenomenon. It was first reached by Sir Hubert Wilkins , who flew by aircraft in 1927; in 1958 a Russian icebreaker reached this point.

7 Territorial claims to the North Pole

Until 1999, the North Pole had been considered international territory. However, as the polar ice has begun to recede at a rate higher than expected (see global warming), several countries have made moves to claim the water or seabed at the Pole. Russia made her first claim in 2001, claiming Lomonosov Ridge , an underwater mountain ridge underneath the Pole, as a natural extension of Siberia. This claim was contested by Norway, Canada, the United States and Denmark in 2004. Denmark's territory of Greenland has the nearest coastline to the North Pole, and Denmark argues that the Lomonosov Ridge is in fact an extension of Greenland. The potential value of the North Pole and the area around resides in its oil and gas, which in the near future might become more accessible after the opening of the North-West Passage.

8 See also

South Pole

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