Earth’s north magnetic pole is moving fast and in an unexpected way, baffling scientists involved in tracking its motions.
Our planet is surrounded by a magnetic field. It is thought to arise from the electric currents generated by Earth’s core—a solid iron ball surrounded by a liquid metal. This field is one of the reasons life is able to thrive as it deflects the solar wind, protecting us from harmful radiation.
However, the magnetic field is constantly moving. At the moment, its north pole is over Canada, but it is slowly making its way toward Siberia. In the early 2000s, NASA announced the pole’s rate of movement had increased to about 25 miles per year.
The changes to the Earth’s magnetic field are tracked with the World Magnetic Model (WMM.) According to the British Geological Survey (BGS), the WMM is used extensively for navigation by the U.S. Department of Defense, as well as many civilian systems. Because of the constant changes, the WMM has to be revised regularly.
In 2014, a new version of the WMM was released. This was due to last until 2020, but last September it had to be revised following feedback from users that “had become inaccurate in the Arctic region,” the BGS said.
Now, the WMM is set to be updated again. A meeting was due to be held on January 15, but because of the U.S. government shutdown, this has been postponed until January 30, Nature magazine reports.
"The error is increasing all the time,” Arnaud Chulliat, a geomagnetist at the University of Colorado Boulder and the National Oceanic and Atmospheric Administration (NOAA), told Nature. He said finding out the WMM had become inaccurate placed scientists in an “interesting situation” with experts wondering just what was going on.
According to Nature, a geomagnetic pulse under South America in 2016 shifted the magnetic field unexpectedly. This was exacerbated by the movement of the north magnetic pole. “The fact that the pole is going fast makes this region more prone to large errors,” Chulliat is quoted as saying.
Researchers are now trying to work out why the magnetic field is changing so quickly. They are studying the geomagnetic pulses, like the one that disrupted the WMM in 2016, which could, Nature reports, be the result of “hydromagnetic” waves emanating from Earth’s core.
To fix the World Magnetic Model, he and his colleagues fed it three years of recent data, which included the 2016 geomagnetic pulse. The new version should remain accurate, he says, until the next regularly scheduled update in 2020.
“The location of the north magnetic pole appears to be governed by two large-scale patches of magnetic field, one beneath Canada and one beneath Siberia,” Phil Livermore, a geomagnetist at the U.K.’s University of Leeds, told the magazine. “The Siberian patch is winning the competition.”