Earth’s magnetic north pole has been moving mysteriously fast toward Siberia for many months. The causes? They were unknown. Now, a team of scientists from the University of Leeds (England) has just come up with a possible explanation that has been published in the journal Nature Geoscience this week and that will have implications for daily navigation and mapping systems, among other things.
Earth is surrounded by a magnetic field that originates in the core of the planet and extends hundreds of kilometers into space. Thanks to this field, which acts like a magnet, the compasses point north.
The Earth’s magnetic field is believed to be generated by the spinning motions of molten iron in the planet’s core. Both poles of the Earth are not stationary, and remain in a permanent state of flux: their positions are constantly moving. Since it was first documented by scientists in the 1830s, the Magnetic North Pole has traveled some 2,250 kilometers through the upper reaches of the Northern Hemisphere from Canada to Siberia. Between 1990 and 2005, the rate of this movement accelerated from less than 15 kilometers per year to around 50 to 60 kilometers per year. The reason for this increase puzzled scientists. It was a mystery. Up to now.
Why is it moving so fast?
The study states that the changes could be explained by the oscillation between two magnetic “drops” of molten material inside the planet (negative magnetic flux), which cause a titanic change in its magnetic field ; that is, two magnetized patches, one under Canada, one under Siberia, along the outer core, are pulling the magnetic north pole.
A tug of war to control pole location
Thanks to this new work, which analyzed a possible cause of this unexpected and “remarkably linear” movement , examining the high resolution geomagnetic data collected over the last two decades, the existence of these two large magnetic patches has been discovered under the regions from Canada and Siberia.
While these patches are typical of the Earth’s magnetic field as a whole, the researchers argue that if examined in isolation, they could explain recent North Pole wanderings. “The current two-patch structure of the high-latitude geomagnetic field defines two ends of a nearly vertical linear field conduit, along which the magnetic north pole can easily travel,” the authors comment.
In this tug of war for control of the location of the magnetic north pole, “now historically, the Canadian patch has won the war and that is why the pole has been focused on Canada, but in recent decades, the Canadian patch has it has weakened and the Siberian patch has strengthened slightly. That explains why it has suddenly accelerated away from its historic position , “experts say.
Let us remember that monitoring the Earth’s magnetic field is not only important for abstract science, but also for day-to-day life: the magnetic field serves as a shield of geomagnetic energy that protects the Earth from destructive solar radiation and is essential for many navigation systems, from the humble compass to GPS.
Referencia: Recent north magnetic pole acceleration towards Siberia caused by flux lobe elongation Philip W. Livermore , Christopher C. Finlay 2 and Matthew Bayliff. Nature Geoscience 2020 DOI: https://doi.org/10.1038/s41561-020-0570-9
