Earth's magnetic north pole is so out of order that scientists need to update the model of the global magnetic field, which they released just four years ago. Could this be a sign that the magnetic pole will soon turn upside down?
The World Magnetic Model (WMM) – the name of the updated representation of the Earth’s magnetic field – is expected to be released no earlier than January 30th. This is about two weeks later than planned, with a delay due to the closure of the government, according to a report in Nature.
The magnetic pole is randomly moving from the Canadian Arctic towards Siberia so unpredictable that it took scientists by surprise. This 2015 update was to remain valid until 2020, said Nature Arno Shullya, a geomagnetist from the University of Colorado at Boulder and the National Center for Environmental Information of the National Oceanic and Atmospheric Administration (NOAA). [Earth’s Colorful Atmospheric Layers Photographed from Space]
This is not news that the pole is moving; long-term records from London and Paris (stored since 1580) show that the north magnetic pole randomly moves around the rotary north pole for several hundred years or longer – Ciaran Beggan, geophysicist from the British Geological Survey, who participates in the WMM Update, Space reported .com in email. He cited a 1981 study from the Philosophical Works journal of the Royal Society of London.
But what really attracts attention is the acceleration of the movement. Around the mid-1990s, the pole unexpectedly accelerated its movement from just over 9 miles (15 kilometers) per year to 34 miles (55 kilometers) per year. As of last year, the pole has passed through the international dating line to the eastern hemisphere.
The main reason for the movement comes from the liquid-iron outer core of the Earth, which is also called the "core of the field." Smaller factors also affect movement. These effects include magnetic minerals in the crust and upper mantle (especially for local magnetic fields) and electrical currents generated by sea water passing through the “surrounding magnetic field”, according to a 2015 WMM report.
“One of the reasons why we can update the map is that the European Space Agency launched a set of high-precision satellites with a magnetic field in 2013,” said Beggan, referring to Swarm.
“We have an excellent data set from which we can create very good magnetic field maps and update them every 6–12 months,” Beggan added. “We noticed that the WMM specification was not fulfilled in the region of high latitudes around the pole, since the error on average exceeded 1 degree of the grid angle. This prompted us to check whether it was worth releasing a new update. ”
Moreover, the field of the nucleus appears to be weakening, which may be a sign that the magnetic field of the planet will roll over. To better understand how this will happen, this is how the core area works, according to Ronald Merrill, an honorary professor of earth sciences and space sciences at the University of Washington, who spoke with the partner site Space.com Live Science.
According to Merrill, who did not participate in the new WMM study, one of the easiest ways to present a field is to think about a rod magnet that passes through the center of the earth and has north and south poles. This magnet is strong, representing approximately 75 percent of the earth’s magnetic field strength on the surface.
Of course, a bar magnet is not an ideal representation — in fact, it is the electrical currents that generate the Earth’s magnetic field — but this model makes it easier to understand what is happening to the Earth, Merrill added. In particular, the “rod magnet” not only moves, but also weakens, by about 7 percent every 100 years.
Regarding the remaining 25 percent of the magnetic field, Merrill said that it is generated from another field, which you can depict as another moving bar magnet. Here is an interesting point: since the central rod magnet loses its intensity, this second, weaker magnetic field has a greater impact on the global magnetism of the Earth. "And this is what makes this field move in the direction [of Siberia]"Merrill said live science.
The north and south poles of the Earth periodically change places, with the last revolution taking place about 780,000 years ago. (The Poles also temporarily and quickly weakened about 41,000 years ago, Beggan added, but never underwent a complete revolution.)) A study conducted in 2018 in the journal “Proceedings of the National Academy of Sciences” showed that the Earth’s magnetic field weakened to .
Despite the fact that there was still a thousand years before any magnetic field reversal, its influence on technology can be significant if it is similar to modern ones. This is due to the fact that a weaker magnetic field would be somewhat worse if the Earth was protected from the solar wind (a constant stream of charged particles emanating from the sun) and cosmic rays (flashes of radiation from deep space). Magnetic compasses will not be as accurate, and satellites that monitor the weather or carry telecommunications signals may be damaged, said Monica Kort, head of the GFZ working group in Potsdam on the evolution of the geomagnetic field in Germany.
“As for the increase in radiation, this will be accompanied by a decrease in shielding, [but] It seems that the atmosphere will still provide sufficient protection on the surface of the Earth so that people and animals are not significantly affected, ”she told Space.com in an e-mail.
“However, all the effects that we see at present only during strong solar / geomagnetic storms are likely to intensify and manifest … during moderate solar activity,” she added. "This includes satellite failures or satellite damage, increased radiation doses on long-range aircraft and the ISS [International Space Station], [and] distortion of telecommunications and GPS signals. "
Court said that the current monitoring of the geomagnetic field of the Earth (which includes the pole) will continue after the release of WMM, mainly through the mission of the European Space Agency Roy. But she noted that measuring the position of the north magnetic pole is a difficult task. This is due to the fact that the pole is located in a remote area, and the measurement of the Earth’s magnetic field is influenced by all sources of the magnetic field, including magnetic fields found in the Earth’s atmosphere (ionosphere and magnetosphere).
“This will depend on the future change in the magnetic field, which we cannot predict if another model update may be required outside the usual schedule,” she added.
According to Beggan, the next WMM update after this year is expected in early 2020. You can read more about WMM here.
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