Woods Hole Marine Magnetism Group
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Magnetic South PoleEarth'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 (or drift in Earth's magnetic field). Australian explorers T.W. Edgeworth David and D. Mawson 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 71deg 36'S 152deg 0'E. Below is a map showing the 1990 measured location of the magnetic south pole [Merrill, McElhinny and McFadden, 1998].
The definition of Earth's magnetic poles depends on what is being defined. The "magnetic north/south 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 pole in 1990 was at 64.9 deg S 138.9deg E The geomagnetic south pole in 1990 was 79.2 deg S 180.9 deg E The following table is a list of historical measured locations for the south dip pole. The last land based location for the magnetic southpole was in 1962. The magnetic southpole has now moved offshore.
For more details on the definition of the different types of magnetic
poles; click here to
go to the AGU website on magnetic poles.
mtivey at whoi dot edu |