Chapter 5: Mobile Mapping Fundamentals

Nicolas MalloyAuthor: Nicolas R. Malloy


5.4 Magnetic North


Magnetic north is the northern pole of the earth’s geomagnetic field. Most people that have used a compass are familiar with the concept of magnetic north. However, you might be surprised to find that magnetic north and true north are not located in the same place.

Geomagnetism is not a fully understood phenomenon. Barring any local magnetic disturbance, the magnetized end of a compass needle will always point towards the north magnetic pole.

Historical track of the magnetic north pole 1590 – 2020 (predicted). The green dot indicates the current (2015) position of the north magnetic pole. This is a screenshot taken from the NOAA Declination Map Viewer.

Historical track of the magnetic north pole 1590 – 2020 (predicted). The green dot indicates the current (2015) position of the north magnetic pole. This is a screenshot taken from the NOAA Declination Map Viewer.

However, the location of this pole is not stable and changes position over time. The rate of change is not always predictable and since the year 2000, the rate of movement of the magnetic pole has increased significantly. Some scientists believe that this is an indication of an imminent pole reversal. Perhaps someday soon compass needles will point south.