Question

The Earth’s magnetic field undergoes periodic reversals. How was this discovered, and by whom? What is the current best theory of its cause?

Answer 1

The first location of the magnetic pole was the June 1, 1831 by the British James Clark Ross , when his boat ran aground on ice in an expedition to the Arctic. Time after 1904 Norwegian Roald Amundsen found the magnetic pole again and discovered that it had been Movio 50 km from Ross discovered it, these men were the first to discover the movement of the magnetic field but tl time did not realize what this really meant.

The first person to estimate the magnetic field was reversione French geophysicist Bernard Brunhes in 1906 and 1920 Japanese geofisoco Motonori discovered Matuyana the Earth's magnetic field had undergone reversals in the past, he observed that rocks with reversed fields were all of early Pleistocene age or older.

An explanation of why this happens is divided but the more scientifically acceptable today that these reversals you are an inherent aspect of the hypothesis of the dynamo. hypotheses that attempt to explain the mechanism by which a celestial body such as the Earth , generates a magnetic field around it.

In the case of the Earth , it is believed that its magnetic field is caused by the convective motion of molten iron and nickel within the external land core as well as the Coriolis effect shown by the planet's rotation . When a conductive fluid moves through an existing magnetic field induced electric currents appear, creating a magnetic field . When this induced field is added to the existing field , the effect is identical to that found in a dynamo : the total field holds himself.

In computer simulations, it is observed that the magnetic field lines can sometimes intertwined and even disorganized by the chaotic movements of the liquid metal of the outer core . This leads to instability , in which the magnetic field spontaneously reverts to the opposite orientation.

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