[caveat emptor]

Magnetic compasses have been in use for 600 years and in that time the Earth's magnetic north pole has barely moved.

Magnaetic declination is a phrase familiar to anyone depending on a magnetic compass for route finding or surveying before the advent of GPS. It's the difference between magnetic north and true north. It varies with location and time.

The declination as well as rate of change at point of use needs to be known to get an accurate direction of geographic north. The rate of change may also change. A straightforward explanation with examples can be found here if you're interested.

For more exotic possibilities of "North", see here, here, and here .

[Salamander]

Those are great links.


Thanks....:)

[pabianice]

Magnaetic declination is a phrase familiar to anyone depending on a magnetic compass for route finding or surveying before the advent of GPS. It's the difference between magnetic north and true north. It varies with location and time.

Sorry, no. The difference between magnetic and true is magnetic variation, not declination. Declination is the term used to describe the angle above the horizon of a celestial body. The difference beyween a mag heading and a compass heading is deviation. Thus: "Timid virgins make dull companions at weddings" -- or: True - add variation - mag - add deviation -- compass -- add west variation (and subtract east).