The Magnetic South Pole
Earth's magnetic south pole is where the magnetic field lines are oriented vertically and come out of the surface of the Earth. The magnetic inclination is thus defined as -90 degrees. The magnetic pole varies in position on a yearly basis due to secular variation (drift in Earth's magnetic field). Two Australian explorers D. Mawson and A. Mackay and British explorer T.W. Edgeworth David were the first to claim to have located the magnetic south pole in 1909 as part of the Shackleton expedition of 1907-1909. However, their location was subsequently found to be incorrect and the most likely location of the pole in 1909 is 71°36'S 152°0'E.
The map shows the measured location of the magnetic south pole (also known as the dip pole) over the past few years [Merrill, McElhinny and McFadden, 1998].
The definition of Earth's magnetic poles depends on what is being defined. The "magnetic north/south dip pole" is the measured location of the vertical field lines. This is different from the "Geomagnetic north/south pole", which is the location where the best fitting dipole model pierces the surface of the Earth. While magnetic poles are not necessarily 180 degrees opposite from one another, Geomagnetic poles are exactly 180 degrees opposite from one another
The magnetic south dip pole in 1990 was at 64.9° S 138.9° E
The geomagnetic axial dipole south pole in 1990 was 79.2° S 180.9° E
The following table is a list of historical measured locations for the south dip pole. The last land based location for the magnetic south dip pole was in 1962. The magnetic south dip pole has now moved offshore.
| Year | Latitude ( °N) | Longitude ( °E) | Expedition |
|---|---|---|---|
| 1903.2 | -72.9 | 156.4 | Scott British Antarctic Exp. |
| 1909 | -71.6 | 152.0 | Shackelton British Antarctic Exp. |
| 1912 | -71.17 | 150.8 | Bage et al. Australasian Antarctic Exp. |
| 1931 | -70.3 | 149.04 | Kennedy, Brit/Aus/NZ exp. |
| 1952 | -68.1 | 143.0 | Mayaud, French South Polar Exp. |
| 1962.1 | -67.5 | 140.0 | Burrows and Hanley Exp. |
| 1986 | -65.3 | 139.167 | Aust. Bureau of Min Resources MV Icebird |
| 2000 | -64.67 | 138.33 | Barton |
For more details on the definition of the different types of magnetic poles; click here to go to the magnetic north pole page and click on the centered dipole pole and eccentric dipole poles. See references below by Fraser-Smith (1986) or Campbell (1997) for more details.
References
Barton, C., Survey tracks current position of South Magnetic Pole, EOS, 291, 2002.
Campbell, W., Introduction to geomagnetic fields, Cambridge University Press, Cambridge, 1997.
Fraser-Smith, A.C., Centered and Eccentric Geomagnetic Dipoles and their poles, 1600-1985, Rev. Geophys., 25, 1-16, 1986.
Merrill, R.T., McElhinny, M.W., and P.L. McFadden, The Magnetic Field of the Earth: Paleomagnetism, the Core and the Deep Mantle, Intl. Geophys. Ser., Vol. 63, pp.531, Academic Press, San Diego, 1998.