The magnetic field of our planet is mysteriously shifting westward due to giant waves arising in the liquid matter of the Earth's core, according to an article published in the journal Royal Society Proceedings A.
“By their nature, they are a kind of antipode of atmospheric oscillations, Rossby waves - in contrast to them, the wave crests in the core always move eastward. At the same time, most of the energy of the magnetic field moves in the opposite direction, to the west,”says Oliver Bardsley from the University of Cambridge (UK).
The position of the poles and where the compass needle points are not a permanent property of our planet. Periodically, about once every 450 thousand or a million years, the north and south poles of the planet change places, traces of which scientists have found in the structure of ancient clays and volcanic rocks. For example, about 40 thousand years ago, the north arrow of the compass would point to the present-day south pole, and the south arrow to the north.
As Bardsley notes, over the past two centuries, they have managed to record many hints that something strange is happening with the planet's magnetic field - its strength decreases quite quickly, 10% every century, and it is gradually shifting west. Both of these phenomena are considered by many geologists to be a sign that the poles may swap positions in the near future.
Bardsley showed that this might not be the case, finding an alternative explanation for why the Earth's magnetic field is constantly shifting westward. As the geologist notes, this idea came to him when he drew attention to the main distinguishing feature of the core of our planet, which distinguishes it from Mars, Venus and other worlds that do not have a magnetic shield.
The Earth's core consists of two layers - a solid inner and a liquid outer core, in which the molten metal moves continuously, generating a magnetic field. This same movement, as Bardsley pointed out, will generate another effect that is well known to all tea and coffee lovers.
On the surface of any liquid, if it is well stirred and made to rotate around a certain point, characteristic bursts begin to appear, which physicists call "Rossby waves." Such waves continuously appear in the Earth's atmosphere, forcing the air currents in its high layers to bend and change the trajectory of movement, shifting towards the west, which generates cyclones and other complex weather phenomena.
If similar oscillations exist in the core of the Earth, then, as Bardsley suggested, they should generate characteristic anomalies in the magnetic field strength, which can be noticed by measuring the deviation in the position of the compass needle from the geographic poles of the planet.
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As shown by the calculations of the geologist, such waves will move to the east, and not to the west, like their atmospheric counterparts. On the other hand, they can transfer energy not in the direction of their movement, but in the opposite direction, due to which the magnetic field will shift to the west, as indicated by four hundred years of observations. Further observations of the field shifts, Bardsley hopes, will confirm or refute his theory.
