SCIENTIFIC EDUCATIONAL CENTER science idea
The massive iron-nickel core of our planet is divided into an internal solid and an external liquid. The convection transfer of heat from the center to the Earth's surface causes the liquid core to constantly mix. It is believed that the movements of this conducting fluid create a global magnetic field that protects the planet and life on it from constant and deadly bombardment by streams of cosmic particles.
On the young Earth, this mechanism of "geomagnetic Dynamo" has not yet worked: the inner core was formed much later than the planet itself — according to various estimates, from 500 million to four billion years ago. The authors of a new paper published in the journal Physical Review Letters report that they have managed to narrow this range to a more acceptable one — 1-1. 3 billion years.
Jung-Fu Lin, a Professor at the University of Texas at Austin, and his colleagues conducted laboratory experiments studying the heat and electrical properties of iron at a huge temperature (3000 Kelvins) and the pressure existing in the inner core of our planet - up to 170 GPA, more than a thousand times more than at the bottom of the Mariana trench, and a million times more than atmospheric pressure.
Tiny samples were heated by laser pulses and squeezed between a pair of diamond "anvils". The experiment helped to evaluate the contribution of various factors to the work of the" geomagnetic Dynamo " and confirmed that today it is supported by the transfer of both matter and heat flows.
In addition, the work allowed us to calculate the intensity of this transfer in the young Earth and more accurately estimate the moment when the planet's interior cooled sufficiently and solid core condensation began in them. And indeed: the period indicated by scientists (1-1. 3 billion years ago) correlates with a sharp surge in the strength of the planet's magnetic field, which is detected by ferromagnetic minerals.
The article is published in the journal Physical Review Letters.
Main photo - © NASA.
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