US, WASHINGTON (ORDO NEWS) — For several years now, scientists have been puzzling over why the North Magnetic Pole rushed to Siberia. Partly thanks to the ESA Swarm satellite mission, scientists are now more confident in the theory that wandering magnetic “clots” deep beneath the Earth’s surface are at the heart of this phenomenon.
Unlike our geographic north pole, which is in a fixed location, magnetic north wanders. This has been known since it was first measured in 1831, and subsequently it slowly moved from the Canadian Arctic to Siberia.
However, since the 1990s, this drift has turned into a sprint – from a historical walk of 0-15 km per year to the current speed of 50-60 km per year. This change in pace led to the fact that the World Magnetic Model had to be updated more often, which, for example, is vital for navigation on smartphones.
Our magnetic field exists because of the ocean of superheated, circulating liquid iron that makes up the outer core. Like a rotating conductor in a bicycle dynamo, this moving “bonfire” creates electric currents, which, in turn, generate our ever-changing magnetic field.
Numerical models based on measurements from space, including from the ESA Swarm mission, allowed scientists to build global magnetic field maps. Tracking changes in the magnetic field can tell researchers how iron moves in the core.
During ESA’s Living Planet Symposium last year, scientists from the University of Leeds in the UK reported that satellite data showed that the position of the north magnetic pole is largely determined by the balance, or tug of war, between two large fractions of the negative flux at the boundary between the Earth’s core and the mantle under Canada.
Based on this, the research team recently published its latest results in Nature Geoscience.
Phil Livermore of the University of Leeds said: “By analyzing the magnetic field maps and their changes over time, we can now accurately determine that the change in the nature of the circulation of the stream under Canada has led to the stretching of the magnetic field at the edge of the core, deep inside the Earth. This weakened the Canadian section and led to a pole shift towards Siberia.”
The big question is whether the pole will return to Canada or continue moving south.
“Models of the magnetic field inside the nucleus suggest that, at least for the next few decades, the pole will continue to drift toward Siberia,” Dr. Livermore explained.
“However, given that the position of the pole is regulated by this delicate balance between the Canadian and Siberian sections, it will take only a small adjustment of the field inside the core to send the pole back to Canada.”
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