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The North Magnetic Pole is the point on the surface of Earth's Northern Hemisphere at which the planet's magnetic field points vertically downwards (in other words, if a magnetic compass needle is allowed to rotate about a horizontal axis, it will point straight down). There is only one location where this occurs, near (but distinct from) the Geographic North Pole and the Geomagnetic North Pole. The North Magnetic Pole moves over time due to magnetic changes in the Earth's core. In 2001, it was determined by the Geological Survey of Canada to lie near Ellesmere Island in northern Canada at . It was situated at in 2005. In 2009, while still situated within the Canadian Arctic territorial claim at ,〔(【引用サイトリンク】title=Magnetic North, Geomagnetic and Magnetic Poles )〕 it was moving toward Russia at between per year.〔(North Magnetic Pole Moving East Due to Core Flux ), National Geographic, December 24, 2009〕 As of 2015, the pole is projected to have moved beyond the Canadian Arctic territorial claim to .〔 Its southern hemisphere counterpart is the South Magnetic Pole. Since the Earth's magnetic field is not exactly symmetrical, the North and South Magnetic Poles are not antipodal, meaning that a line drawn from one to the other does not pass through the geometric centre of the Earth. The Earth's North and South Magnetic Poles are also known as Magnetic Dip Poles, with reference to the vertical "dip" of the magnetic field lines at those points. ==Polarity== All magnets have two poles, where the lines of magnetic flux enter and emerge. By analogy with the Earth's magnetic field, these are called the magnet's "north" and "south" poles. The convention in early compasses was to call the end of the needle pointing to the Earth's North Magnetic Pole the "north pole" (or "north-seeking pole") and the other end the "south pole" (the names are often abbreviated to "N" and "S"). Because opposite poles attract, this definition means that the Earth's North Magnetic Pole is actually a magnetic ''south'' pole and the Earth's South Magnetic Pole is a magnetic ''north'' pole. The direction of magnetic field lines is defined such that the lines emerge from the magnet's north pole and enter into the magnet's south pole. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「North Magnetic Pole」の詳細全文を読む スポンサード リンク
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