Earth's magnetic fields are shifting at an unprecedented rate, according to a new report from the European Space Agency (ESA). While scientists believe this point has always wandered, exactly what is driving the recent acceleration remains unknown.
“While this has some practical implications, scientists believe it is caused by the collision of magnetic clots deep beneath our feet,” explains ESA.
The geographic North Pole is at a fixed location, but magnetic north has been known to be shifting since it was first measured in 1831. Since then, it has been slowly drifting from the Canadian Arctic to Siberia.
As a result, the World Magnetic Model (WMM) must be changed every few years with the pole's current location in order for navigation systems such as those used by ships, Google maps, and smartphones to be up to date. Recently, due to the accelerated speed, the WMM poles had to be updated earlier than usual.
Between 1990 and 2005, the speed of the magnetic field in the North increased from 0-15 kilometers per year to 50-60 kilometers per year. In 2017, it crossed the international date line 390 kilometers from the geographic North Pole and continues south.
Our magnetic field exists from across the ocean of superheated, swirling liquid iron that makes up the outer core. Like the rotating conductor in a bicycle Dynamo, this moving iron creates electrical currents, which in turn generate our ever-changing magnetic field.”
This means that tracking changes in the magnetic field can give experts an idea of how iron is moving in the core.
“Several theories have been proposed to explain this behavior, but because they rely on changes in a small magnetic field, they cannot explain the recent trajectory of the pole,” explains Phil Livermore of the University of Leeds.
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“Using data collected over two decades by satellites, we can see that the position of the magnetic N Pole is determined mainly by the balance, or tug of war, between the two large lobes of negative magnetic flux at the boundary between the Earth's core and mantle beneath Canada and Siberia.”
According to ESA data, changes in the nature of the core flow between 1970 and 1999 lengthened the Canadian lobe and weakened its influence on the earth's surface, as a result of which the pole began to move faster towards Siberia. Over the next decade, the magnetic north pole is projected to travel another 390-660 kilometers towards Siberia.