Geographic North/True North
Geographic
North, otherwise known as True North, is what one would follow when heading towards the North Pole. It is located at the end of the axis that the Earth is rotating
on (in the northern hemisphere) and this fixed location determines
the lines of longitude and latitude (for all the lines of latitude intersect at
the North Pole). When following a map, the picture compass always points towards true north.
Magnetic North
Magnetic
North is a point in the arctic that constantly shifts and is controlled by the
Earth’s magnetic field. The magnetic field is generated by the Earth’s liquid
metal core that circulates due to the earth’s constant rotation. Electric
currents are created and thus the magnetic field is formed. Due to the constant
shifting field, the magnetic north and the geographic north are not aligned. When
using a compass, the north end always points to the magnetic north. But then again,
opposite ends of the magnet attract. Therefore it is concluded that the
magnetic north is actually the Earth’s south pole. Since the Earth’s core acts
as a huge magnet, it means that the south end is actually in the northern hemisphere and the magnetic field lines of the Earth flow out of the magnetic south pole and into the magnetic north pole.
Physical North
Physical
North is the direction of north from a person’s perspective. The direction
varies depending on where one is standing. Since there is so much variety,
there is no specific physical north.
References:
Conger, C. (n.d.). HowStuffWorks "Introduction to How to Find True North". HowStuffWorks "Adventure". Retrieved February 25, 2013, from http://adventure.howstuffworks.com/survival/wilderness/true-north.htm
The Dynamic Earth @ National Museum of Natural History. (n.d.). Smithsonian Institution National Museum of Natural History NMNH. Retrieved February 24, 2013, from http://www.mnh.si.edu/earth/text/4_1_5_0.html