True North
True North refers to the direction of the North Pole from any location on Earth and is often confused with magnetic north. Unlike True North, which is the direction indicated by converging lines of longitude on a map or globe, magnetic north is determined by Earth's magnetic fields and points to a location that moves slightly over time in the Arctic. A compass, which is calibrated to magnetic north, does not provide a direct path to the North Pole, necessitating adjustments for accurate navigation. This adjustment involves understanding the concept of magnetic declination, which is the angle between True North and magnetic north and varies by geographic location. For instance, declination is approximately twenty degrees west in Maine and ten degrees east in Texas. Accurate navigation requires travelers to use up-to-date maps, as the magnetic north pole drifts at an accelerating rate of about 34 miles per year. Understanding the distinction between the two types of north is crucial for effective navigation, especially in wilderness or remote areas.
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True North
True North is the direction of the North Pole from any point on Earth. Many people confuse True North with magnetic north. A compass points to magnetic north, which is a point in the Arctic off the coast of Greenland that moves slightly based on the activity of Earth's magnetic fields. For this reason, it is not possible to use a compass to get to the North Pole. On a map or globe, True North is represented by converging lines of longitude.
Overview
True North is directly north on a map or globe. It is the direction of each line of longitude that converges with other lines of longitude at the North Pole, which is the axis upon which Earth rotates. True North is the direction most people refer to when they think of north. However, another type of north exists.
The needle on a compass points to the north, but it does not point to True North. It instead points to magnetic north. Earth's core acts like an enormous magnet that creates a magnetic field, or an electric current. Like other magnets, one end is positively charged and the other end is negatively charged. The focal points of the positively charged end and the negatively charged end are known as magnetic north and magnetic south. These magnetic points are what a compass reads, but they do not line up perfectly with the North and South Poles. Because Earth's core is not solid, magnetic poles are constantly moving although this movement is slow and predictable.
Researchers in France attempted to find the magnetic north pole in 2007 and placed it at the coordinates 83.95 degrees north (latitude) by 120.72 degrees west (longitude). The rate at which the magnetic north pole drifts has been accelerating over time and was last observed to be drifting about 34 miles each year. Expeditions to find the magnetic north pole have mostly ceased, mainly because the pole continues to move northwest and, therefore, farther into the Arctic and away from civilization.
Those navigating with a map and a compass need to know how to adjust the compass's reading to find True North. The difference between the two is called the magnetic declination, or declination. Declination is actually an angle measuring the difference between True North and magnetic north. Declinations vary from place to place depending on the strength of Earth's magnetic fields. For example, the declination in Maine is about twenty degrees west while the declination in Texas is about ten degrees east.
Most maps provide a declination to use in a particular area. With this information, it is not difficult to find True North. Travelers can find the magnetic north pole with a compass and then rotate the number of degrees indicated on their map in the specified direction, either east or west. Because the location of the magnetic north pole changes over time, it is important for travelers to use a recent map.
Bibliography
Curtis, Rick. "The Backpackers Field Manual." Princeton.edu. Princeton University and Random House Publishing. Web. 8 Jul. 2014. www.princeton.edu/~oa/manual/mapcompass2.shtml
Ordinance Survey. "Grid North, Magnetic North, and True North." Ordinance Survey. Ordinance Survey. Web. 8 Jul. 2014. http://www.ordnancesurvey.co.uk/resources/maps-and-geographic-resources/finding-north.html
National Geophysical Data Center. "Wandering of the Geomagnetic Poles." National Geophysical Data Center. National Oceanic and Atmospheric Administration. Web. 8 Jul. 2014. http://www.ngdc.noaa.gov/geomag/GeomagneticPoles.shtml