The magnetic north pole is the point on the Earth that compasses designate as true north. It is the result of geological processes deep within the planet—molten iron flow creates a magnetic field with poles near the geographic North and South Poles. But unlike the geographic poles, the magnetic poles can move—and the magnetic north pole has been moving faster in recent years, which made necessary the early update of the WMM.

The WMM is a model maintained jointly by the U.S. National Oceanic and Atmospheric Administration and the British Geological Survey—its purpose is to show what Earth's magnetic field looks like, most particularly, where the locations of the magnetic poles lie.