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Physics
Classical Physics
Electromagnetism
Generation of magnetic fields....
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[QUOTE="billslugg, post: 5473671, member: 300308"] The Earth's magnetic field generation system is driven by heat generation in the core and the spinning of the Earth on its axis. There is molten, conductive material trapped between the solid core and the solid crust. As plumes of it rise they experience Coriolis force and move counterintuitively, mainly sideways. As the conductive material in a rising plume moves sideways it cuts the Earth's magnetic field. This induces large currents in the plume. These currents generate the Earth's magnetic field. The system is self sustaining. Small primordal fields in the core material probably got it started. I have heard of the need to sometimes tap a new alternator in a car to get it going. By tapping it, the atoms align with the Earth's magnetic field and thus become slightly magnetic thus inducing a tiny current in the field. This current causes a larger field thus more current thus more field until it is operating normally. The field reversals are periodic behaviors in an otherwise chaotic system. They are perhaps caused by large scale changes in heat transfer rates and heat storage caused by the movement of continental masses. There is, for example, a toroidal convection overturn within the Earth's interior every billion years or so. As the continents gather together into a supercontinent,it slows the heat removal from the core below it. The material under a supercontinent grows warmer over a billion years. The antipode had no continents thus cooled the core more quickly. When, at some point, the density difference under one half of the Earth versus the other half becomes great enough the toroidal convection reverses. A now hot megaplume splits the continents apart and sends them to the antipode to join together in another billion years or so. This cycle started when the infall of solids towards the primordal core got asymmetric and a toroidal convection event occured. I have read that the initial overturn occurred in only a week or so. [/QUOTE]
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Generation of magnetic fields....
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