Japanese Magnetic North, Geomagnetic and Magnetic Poles

Magnetic north   Geomagnetic poles   Magnetic poles
Maps and table showing the locations of geomanetic and magnetic poles.
Secular variation of geomagnetic dipole moment

Figure 1  Locations of geomagnetic poles and magnetic poles based on IGRF-12 from 1900 to 2010 by 5 years and at 2015 (red) and 2020 (prediction).
North geomagnetic and magnetic poles

North geomagnetic poles and north magnetic poles. Click on the figure to display a larger view.
South geomagnetic and magnetic poles

South geomagnetic poles and south magnetic poles. Click on the figure to display a larger view.

The Earth is associated with the geomagnetic field that has an S (N) -pole of a magnet near the North (South) Pole. A magnetic compass, therefore, approximately points toward the north. However, the pointing direction is slightly different from the true north by an angle called "declination". Also, two pairs of poles can be defined for the geomagnetic field: the geomagnetic poles and the magnetic poles. The magnetic north corresponds to neither pole, since the geomagnetic field actually has a more complicated shape than a magnetic field generated by a bar magnet (See below). Moreover, a magnetic needle suspended at a center of balance does not keep horizontal. As a rule, the N-pole dips downward by an angle called "inclination" in the northern hemisphere.

If we rotate a compass for southern hemisphere in Japan... (MPG:2.3MB)

The Geomagnetic poles (dipole poles) are the intersections of the Earth's surface and the axis of a bar magnet hypothetically placed at the center the Earth by which we approximate the geomagnetic field. There is such a pole in each hemisphere, and the poles are called as "the geomagnetic north pole" and "the geomagnetic south pole", respectively. On the other hand, the magnetic poles are the points at which magnetic needles become vertical. There also are "the magnetic north pole" and "the magnetic south pole". The geomagnetic or magnetic south (north) poles correspond to the N (S) -pole of a magnet. In Table 1 and Figure 1 , we show predicted locations of the geomagnetic and magnetic poles by "International Geomagnetic Reference Field" (IGRF-12) from 1900 through 2020. These poles are drifting according to slow and smooth change in the geomagnetic field called "the geomagnetic secular variation".

In Figure 2, we show the predicted declination at Kyoto in 2015 by IGRF-12 in addition to the predicted directions towards the geomagnetic and magnetic north poles. The reason why we have now westward declination in Japan is probably due to the presence of a strong positive geomagnetic anomaly around Lake Baikal in Siberia. The N-poles of magnetic needles tend to be attracted to the anomaly to show westward declinations around Japan.

Model field by IGRF

Animation of secular variation in geomagnetic total intensity for the last 400 years.

Year North geomagnetic pole South geomagnetic poleNorth magnetic pole South magnetic pole Dipole moment
Lat.Long. Lat.Long. Lat.Long. Lat.Long.
1900 78.7N 68.8W 78.7S 111.2E 70.5N 96.2W 71.7S 148.3E 8.32
1905 78.7N 68.7W 78.7S 111.3E 70.7N 96.5W 71.5S 148.5E 8.30
1910 78.7N 68.7W 78.7S 111.3E 70.8N 96.7W 71.2S 148.6E 8.27
1915 78.6N 68.6W 78.6S 111.4E 71.0N 97.0W 70.8S 148.5E 8.24
1920 78.6N 68.4W 78.6S 111.6E 71.3N 97.4W 70.4S 148.2E 8.20
1925 78.6N 68.3W 78.6S 111.7E 71.8N 98.0W 70.0S 147.6E 8.16
1930 78.6N 68.3W 78.6S 111.7E 72.3N 98.7W 69.5S 146.8E 8.13
1935 78.6N 68.4W 78.6S 111.6E 72.8N 99.3W 69.1S 145.8E 8.11
1940 78.5N 68.5W 78.5S 111.5E 73.3N 99.9W 68.6S 144.6E 8.09
1945 78.5N 68.5W 78.5S 111.5E 73.9N 100.2W 68.2S 144.4E 8.08
1950 78.5N 68.8W 78.5S 111.2E 74.6N 100.9W 67.9S 143.5E 8.06
1955 78.5N 69.2W 78.5S 110.8E 75.2N 101.4W 67.2S 141.5E 8.05
1960 78.6N 69.5W 78.6S 110.5E 75.3N 101.0W 66.7S 140.2E 8.03
1965 78.6N 69.9W 78.6S 110.1E 75.6N 101.3W 66.3S 139.5E 8.00
1970 78.7N 70.2W 78.7S 109.8E 75.9N 101.0W 66.0S 139.4E 7.97
1975 78.8N 70.5W 78.8S 109.5E 76.2N 100.6W 65.7S 139.5E 7.94
1980 78.9N 70.8W 78.9S 109.2E 76.9N 101.7W 65.4S 139.3E 7.91
1985 79.0N 70.9W 79.0S 109.1E 77.4N 102.6W 65.1S 139.2E 7.87
1990 79.2N 71.1W 79.2S 108.9E 78.1N 103.7W 64.9S 138.9E 7.84
1995 79.4N 71.4W 79.4S 108.6E 79.0N 105.3W 64.8S 138.7E 7.81
2000 79.6N 71.6W 79.6S 108.4E 81.0N 109.6W 64.7S 138.3E 7.79
2005 79.8N 71.8W 79.8S 108.2E 83.2N 118.2W 64.5S 137.8E 7.77
2010 80.1N 72.2W 80.1S 107.8E 85.0N 132.8W 64.4S 137.3E 7.75
2011 80.1N 72.3W 80.1S 107.7E 85.4N 137.4W 64.4S 137.2E 7.74
2012 80.2N 72.4W 80.2S 107.6E 85.7N 142.5W 64.4S 137.0E 7.74
2013 80.3N 72.5W 80.3S 107.5E 85.9N 148.0W 64.3S 136.9E 7.73
2014 80.3N 72.5W 80.3S 107.5E 86.1N 153.9W 64.3S 136.7E 7.73
2015 80.4N 72.6W 80.4S 107.4E 86.3N 160.0W 64.3S 136.6E 7.72
2016 80.4N 72.7W 80.4S 107.3E 86.4N 166.3W 64.2S 136.4E 7.72
2017 80.5N 72.8W 80.5S 107.2E 86.5N 172.6W 64.2S 136.3E 7.72
2018 80.5N 73.0W 80.5S 107.0E 86.5N 178.8W 64.2S 136.1E 7.71
2019 80.6N 73.1W 80.6S 106.9E 86.4N 175.3E 64.1S 135.9E 7.71
2020 80.6N 73.2W 80.6S 106.8E 86.4N 169.8E 64.1S 135.8E 7.70
Locations of magnetic and geomagnetic poles in geodetic coordinate and dipole moment based on IGRF including prediction.
Graph showing secular variation of geomagnetic dipole moment since 1835 is here
Magnetic north and directions
of geomagnetic and magnetic poles at Kyoto
Inclination at Kyoto

Figure 2   Magnetic north and directions of geomagnetic and magnetic poles (left) and inclination (right) at Kyoto (35.0N, 135.8E) at 2015 based on IGRF-12.