In Finland inclination varies between 73 deg and 78 deg from south to north and its annual change is 1'. The former value occur at the northern geomagnetic pole which is located in Canadian Archipelago approximately at 78 N and 100 W, some 1000 km south of the true North Pole. Its southern counterpoint lies near Antartica about 400 km south of the Australian coast. The map shows the mean distribution of the horizontal component of the geomagnetic field vector in Finland. The direction of the H-vector determines the orientation of the needle in a magnetic compass.
Declination is the angle between the true North direction and that of the compass needle.
H in Finland is decreasing annually about 10 nT. This means that the force keeping the needle in a magnetic compass is slowly weakening. This change in Finland strengthens the geomagnetic field here opposite to what is the global trend in the Earth's dipole field intensity which is decreasing about 1 promille annually. An interactive Java-applet for plotting the International Geomagnetic Reference Field is also available.