New research from the University of Leeds and the University of California at San Diego has found that changes in the direction of Earth’s magnetic field are skyrocketing: they take place 10 times faster than previously thought.
The Earth’s magnetic field extends around the entire Earth (from the nucleus to the magnetosphere) and serves as a guide to the different geographic orientation systems.
It is generated by the temperature difference between the Earth’s outer core (composed mainly of liquid iron and with a weak magnetic field) and the Earth’s mantle.
Unusual speed
In addition to this, the rotation of the Earth creates electric currents that continuously modify the electromagnetic field (as a consequence of what is known as the dynamo effect).
In recent years, the movement of the Earth’s magnetic field has accelerated, while its strength has decreased.
Last year, scientists verified that the magnetic North Pole is becoming moving at an unusual speed 55 kilometers per year: advances from Canada to Siberia at an unusual speed.
Specialists think these variations are related to changes in the way liquid iron flows in Earth’s outer core.
Faster still
The new study, published in Nature Communications, states that changes in the direction of Earth’s magnetic field reach rates of up to one degree per year.
The new research combined computer simulations of the magnetic field generation process with a previously published reconstruction, which collects time variations in Earth’s magnetic field over the past 100,000 years.
The new data confirms that these accelerated changes are associated with local weakening of the magnetic field. This means that these changes have generally occurred at times when the field has reversed polarity.
It may also be that these changes have occurred during geomagnetic excursions: they occur when the dipole axis, corresponding to the field lines emerging from one magnetic pole and converging on the other, moves away from the North and South locations of the geographic poles. .
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