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The last poles flip happened 780,000 years ago, and last decades scientists report acceleration in the movement of the Earth magnetic poles.
Flip of magnetic poles would have profound effect on modern human civilisation.
This occurs in relatively cold tectonic plates, called slabs, which are found especially beneath the western Pacific Ocean.
"This new knowledge about the Earth's mantle and the strongly magnetic region in the western Pacific could throw new light on any observations of the Earth's magnetic field," says mineral physicist and first author Dr.
The old well-known sources of the Earth's magnetic field are the Earth's core -- down to 6,000 kilometres deep down inside the Earth -- and the Earth's crust: in other words, the ground we stand on.
The Earth's mantle, on the other hand, stretching from 35 to 2,900 kilometres below the Earth's surface, has so far largely been regarded as "magnetically dead." An international team of researchers from Germany, France, Denmark and the USA has now demonstrated that a form of iron oxide, hematite, can retain its magnetic properties even deep down in the Earth's mantle.
Relevance for investigations of the Earth's magnetic field and the movement of the poles By using satellites and studying rocks, researchers observe the Earth's magnetic field, as well as the local and regional changes in magnetic strength.
The researchers are therefore considering the possibility that the magnetic fields observed in the Pacific with the aid of rock records do not represent the migration route of the poles measured on the Earth's surface, but originate from the hitherto unknown electromagnetic source of hematite-containing rocks in the Earth's mantle beneath the West Pacific.
"What we now know -- that there are magnetically ordered materials down there in the Earth's mantle -- should be taken into account in any future analysis of the Earth's magnetic field and of the movement of the poles," says co-author Prof.
"As a result, we are able to demonstrate that the Earth's mantle is not nearly as magnetically 'dead' as has so far been assumed," says Prof.
Carmen Sanchez-Valle from the Institute of Mineralogy at Münster University.