The earth's magnetic pole is the focus of the planet's magnetic field and is the point that traditional magnetic compasses point toward. Compasses are also subject to magnetic declination which is a result of the earth's varied magnetic field. Each year, the magnetic North Pole and the magnetic field shift, requiring those using magnetic compasses for navigation to be keenly aware of the difference between magnetic north and true north. The magnetic pole was first determined in 1831, hundreds of miles from its present location.
The National Geomagnetic Program of Geological Survey of Canada monitors the movement of the north magnetic pole and most recently determined its precise location in a 2001 survey. They've determined that the pole is moving at approximately 25 miles (40 kilometers) each year.
The north magnetic pole moves on a daily basis, too. Every day, there's an elliptical movement of the magnetic pole about 50 miles (80 kilometers) from its average center point.