The fast journey of the magnetic North Pole towards Siberia measured by the European Swarm satellites

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The race of the north magnetic pole towards Siberia has been confirmed through the observations of the European Swarm satellites. The INGV study, just published in the prestigious American Journal of Geophysical Research, illustrates the details

With a speed eight times greater than the one of the south magnetic pole, the north magnetic pole is moving towards Siberia. A new analysis carried out for the first time on the data produced by the Swarm satellites of the European Space Agency (ESA) currently in orbit, confirmed the trend that had been observed in recent decades. In the study just published “The location of the Earth’s magnetic poles from circum-terrestrial observations”, three scientists of the Italian National Institute of Geophysics and Volcanology (INGV) show how from the direct measurements of the magnetic field recorded by the instruments on board the satellites it is possible to determine the updated position of the magnetic poles and, analyzing the data of recent years, also their dynamics.

“Since their launch in 2013”, says Domenico Di Mauro, scientist at INGV and author of the study, “the three Swarm satellites complete near polar orbits in about 95 minutes. In 24 hours, they perform 15 turns around the Earth’s sphere, thus collecting information on the morphology and intensity of the magnetic field with very high precision instruments and returning measurements with a resolution and space-time coverage never achieved before. An opportunity that we, INGV researchers working in the field of geomagnetism, could not miss: we thus determined, updating it, the position of the magnetic poles as if the measurement were collected on the ground. To do this, we have developed procedures and algorithms to project on the Earth’s surface the data collected at high altitude, an analysis carried out for the first time in the era of the exploration of our planet from Space”

“The results”, adds Mauro Regi, scientist at INGV and first author of the study, “in accordance with the current 13th generation of the international reference model of the geomagnetic field (IGRF), have the prerogative of providing immediate and direct information by experimental observations. Both magnetic poles move in a northwest direction but while the north pole moves at the speed of about 37-72 km per year (with a slight decrease in the year 2016), the speed of the south pole is about 5- 9 km per year. From our analyses, therefore, the magnetic north pole has abandoned the northern territories of Canada and is heading towards Siberia, while the magnetic south pole moves more slowly towards the open ocean, from the Antarctic sector which houses the French station Dumont D’Urville”.

“It is important to underline”, concludes Stefania Lepidi, scientist at INGV and co-author of the study, “the profound difference between magnetic poles and geographical poles: the latter are identified by the Earth’s rotation axis and, therefore, are fixed. The magnetic poles, on the other hand, correspond to the points where the magnetic field is exactly vertical and move in an unpredictable way. Furthermore, the magnetic poles are not diametrically opposite as the geographic ones are and they are not even close to them. Today the south magnetic pole is about 2800 km from its geographical counterpart, the north one about 350 km”.

The bizarre behavior of the magnetic poles has stimulated the curiosity of some explorers in the last two centuries, daring to face the difficult environmental conditions of the polar areas of our planet: the precious measurements collected over time have made it possible to follow the incredible distances covered by the two magnetic poles, as a manifestation of the slow but continuous space-time variation of the magnetic field as a consequence of the complex mechanisms that generate it in the outer core of our planet.

 

(Fonte Ingv)