The Many Types of North

[Untitled image of the Earth's poles]. Retrieved February 22, 2013, from:

     http://www.mnh.si.edu/earth/text/4_1_5_0.html

              Geographic north is based on the axis that the earth rotates around.  If we were to draw a line through the Earth that represents this axis, the point in the northern hemisphere where this line exits the Earth would be geographic north. This is also sometimes referred to as true north. All of our latitude and longitude lines are based off of the geographic north and south poles (DiSpezio, 2011).

EarthsMagneticField. Retrieved February 22, 2013, from:http://www.circulatethis.com/the-earths-magnetic-field-can-effect-more-than-just-your-compass-and-gps

              Magnetic north is determined by the Earth's magnetic field. This magnetic field is generated due to the liquid metal inside the Earth, the convection that takes place and the rotation of the Earth. Magnetic north is where the north end of a magnetic compass is attracted to. If you were to stand directly on top of the magnetic north pole, the compass would point straight down (Riddle, 2013). Since the opposite ends of magnets attract each other, the magnetic north pole is actually the Earth's physical south pole, and the magnetic south pole is the Earth's physical north pole. The magnetic field lines of the Earth move out from the pole in the southern hemisphere and into the pole in the northern hemisphere. Therefore when comparing to Earth to a bar magnet, the south pole is actually in the northern hemisphere as seen in the picture to above (Casselman, 2008).

                The geographic and magnetic poles are not in the same location, and the magnetic poles are constantly changing due to changes in the Earth. This difference can be determined through the use of magnetic declination or the degree of difference between the two poles (DiSpezio, 2011). 

References

(1) Casselman, A. (2008, February 28). Scientificamerican.com. Retrieved from                     

                    http://www.scientificamerican.com/article.cfm?id=the-earth-has-more-than-one-north-pole

(2) DiSpezio, M. A. (2011). Polar misunderstandings: Earth's dynamic dynamo. Science Scope, 35(2), 16-21.

(3) Riddle, B. (2013). Which way is north?. Science Scope, 36(5), 84-86.