You are welcome to join us for an Archaeological Society talk at the KwaZulu-Natal Museum in Pietermaritzburg at 10.30 am on Saturday, 16 March 2024.
The address is 237 Jabu Ndlovu Street, Pietermaritzburg.

 

The Earth’s magnetic field is generated in the metallic liquid outer core. It can be envisaged as a bar magnet, with lines of force that currently stream out of the Magnetic South Pole and then circle round the Earth to stream back in at the Earth’s Magnetic North Pole. The Magnetic Poles do not quite correspond with the Geographic Poles but migrate around in their general vicinity. Periodically the intensity of the magnetic field decreases, decaying into a quadrupole with two Magnetic North Poles and two Magnetic South Poles. When the magnetic intensity increases again into a dipole system, sometimes the Magnetic North and South Poles have switched positions, a process known as a magnetic reversal. When magnetic minerals, such as magnetite, crystallise, they record the characteristics of the Earth’s magnetic field at that time. Palaeomagnetic studies involve measuring the Earth’s magnetic field preserved in such minerals. By analysis of magnetic minerals in archaeological artefacts, it is possible to determine the variation in positions of the Magnetic Poles, the time of magnetic reversals and the intensity of the Earth’s magnetic field. This talk discusses combined palaeomagnetic and archaeological research focused on changes in the Magnetic Poles in the past 2000 years.

 

Please contact me or Ghilraen Laue (glaue@nmsa.org.za) if you would like to attend.