René Jansen, Regional Manager EDAX EMEA
Last week there was a news item on the radio which struck my mind. How is it possible that we have a magnetic North and South Pole on our earth for billions of years? A pair of planetary scientists has come up with a new theory to help explain the mechanism behind the generation of the Earth’s magnetic field.*
For many years, scientists have believed that the Earth’s magnetic field is likely generated by energy that is released as the core cools and material solidifies. But, there is a problem with that idea, scientists also believe that the core did not cool enough to form an inner core, until approximately one billion years ago.
In their paper published in the journal Nature the scientists suggest that 1 percent of magnesium that made its way to the core of the planet could be the key to understanding how the magnetic field was generated in the past and what drives it in the present.
Because magnesium is only soluble in iron at very high temperatures, they believe that it is slowly precipitating out to the boundary between the core and the mantle. That process would leave the iron behind denser, which would cause the release of energy, which they suggest could explain the power source behind the dynamo.
This interesting theory relies on understanding the compositional changes of a system with time and temperature. It is very similar to analyses proposed and investigated every day by our users of microanalysis products on modern materials. It is remarkable that the same techniques are proposed for understanding both planetary core dynamics and nanotechnology.
* Powering earth’s dynamo with magnesium precipitation from the core.