<Tr> <Td> </Td> <Td> This section does not cite any sources . Please help improve this section by adding citations to reliable sources . Unsourced material may be challenged and removed . (May 2017) (Learn how and when to remove this template message) </Td> </Tr> <P> The direction in which a compass needle points is known as magnetic north . In general, this is not exactly the direction of the North Magnetic Pole (or of any other consistent location). Instead, the compass aligns itself to the local geomagnetic field, which varies in a complex manner over the Earth's surface, as well as over time . The local angular difference between magnetic north and true north is called the magnetic declination . Most map coordinate systems are based on true north, and magnetic declination is often shown on map legends so that the direction of true north can be determined from north as indicated by a compass . </P> <P> Magnetic declination has been measured in many countries, including the U.S. The line of zero declination (the agonic line) in North America runs from the North Magnetic Pole through Lake Superior and southward into the Gulf of Mexico . Along this line, true north is the same as magnetic north . West of the line of zero declination, a compass will give a reading that is east of true north . Conversely, east of the line of zero declination, a compass reading will be west of true north . </P> <P> Magnetic declination is still very important for certain types of navigation that have traditionally made much use of magnetic compasses . </P>

The location of the geographic north pole stays the same