The Earth's north-magnetic pole is so bad that scientists have to update the worldwide magnetic field model released just four years ago. Can this be a sign that the magnetic pole will turn soon?
The World Magnetic Model (WMM) – the name of the updated representation of the Earth's magnetic field – is expected to be released earlier than January 30. about two weeks later than planned, with the delay due to government closures, according to a report in nature.
The magnetic pole moves illegally from the Canadian Arctic and to Siberia so unpredictably that it surprised scientists. The 2015 update would remain valid until 2020, Arnaud Chulliat, a geomagnetist at the University of Colorado Boulder and the National Ocean and Atmospheric Administration (NOAA) National Environmental Information Centers, told Nature. [Earth’s Colorful Atmospheric Layers Photographed from Space]
It is no news that the pole is moving; Long-term records from London and Paris (held since 1580) show that the north magnetic pole is moving illegally around the rotating north pole over a few hundred years or more, Ciaran Beggan, a geophysicist with the British Geological Survey. involved in WMM updates, Space.com said in an email. He quoted a 1981 study from the Royal Society of London magazine Philosophical Transactions.
But what gets scarce attention is the acceleration in motion. Around the mid-1990s, the pole suddenly pushed its movements from just over 9 kilometers (15 kilometers) per year to 55 kilometers per year. Since last year, the pole has looked over the international date line to the Eastern Hemisphere.
The main cause of the movement comes from the Earth's liquid iron outer core, also called the "core field". Smaller factors also affect the movement. These influences include magnetic minerals in the crust and upper mantle (especially for local magnetic fields) and sea currents electric currents move through a "surrounding magnetic field", according to the 2015 WMM report.
"One of the reasons we can update the map that the European Space Agency launched a set of highly accurate magnetic field satellites in 2013," Beggan, referring to Swarm, began.
"We have an excellent data set from which we can make very good magnetic field-maps and work them every six to twelve months," Beggan added. "We noticed that the specification of the WMM was not met in the high latitude around the pole, as the error exceeded an average of 1 degree of the grid angle, which led us to investigate if it was worth & # 39; give a new update. "
What looks like is the core field weakening – which may be a sign that the planet's magnetic field will flip. To better understand how this would happen, here's how the core field works, according to Ronald Merrill, an emeritus professor of Earth and Space Sciences at the University of Washington, who with Space.com's sister site, Live Science talked.
An easy way to imagine the field is to think of a bar magnet passing through the Earth's center and having a north pole and a south pole, Merrill said. He was not involved in the new WMM research. The magnet is strong, representing about 75 percent of the earth's magnetic field intensity on the surface.
Of course, a bar magnet is not a perfect representation – it's actually electric currents that generate the earth's magnetic field – but make the model It's easier to think what happens to Earth, Merrill added. Specifically, the "bar magnet" not only moves, but also gets worse, with about 7 percent every 100 years.
As for the other 25 percent of the magnetic field, Merrill said it was generated from another field, which you could photograph as another moving bar magnet. Here's an interesting bit: As the central bar magnet loses intensity, this second, weaker magnetic field generates more influence on Earth's global magnetism. "And that's what causes this field to move in the direction [of Siberia]," Merrill told Live Science.
The north and south poles of the Earth range from time to time, with the last flip occurring about 780,000 years ago. (The poles also weakened temporarily and rapidly about 41 000 years ago, Beggan added, but never underwent a full flip.)) A 2018 study in the journal Proceedings of the National Academy of Sciences suggested that the Earth's magnetic field had become weaker before the great transition.
Although any magnetic field flip would still be thousands of years away, the effects could be on technology, if similar to today's technology. This is because the weaker magnetic field would be slightly poorer to protect the Earth from the solar wind (the constant current of charged particles coming from the sun) and cosmic rays (radiations of radiation from the deep space). Magnetic compasses will not be as accurate, and satellites that monitor the weather or carry telecommunications signals can be disrupted, Monika Korte, head of GFZ Potsdam's work group on geomagnetic field development in Germany, said.
"As for the increased radiation, it would agree with decrease in shielding, [but] it appears that the atmosphere will still provide enough protection against the earth, that people and animals will not be significantly affected," she said. to Space.com in an email.
"All the effects we currently see only during strong solar / geomagnetic storms are likely to increase and occur … during moderate solar activity," she added. "These include satellite interruptions or satellite damage, increased radiation doses to long-haul aircraft and the ISS [International Space Station][and] telecommunications and GPS signal distortions."
Continuous monitoring of the Earth's geomagnetic field (which will continue the pole) following the WMM release, mainly by the European Space Agency Swerm Mission, Korte said. But she noted that measuring the north-magnetic pole's position is a challenge. This is because the pole is located in a remote area and the measurement of the Earth's magnetic field is influenced by all magnetic field sources – including the magnetic fields that occur in the Earth's atmosphere (the ionosphere and magnetosphere).
"It will depend on the future magnetic field change, which we cannot predict, if another update of the model from the regular schedule may be necessary," she added.
The next update to the WMM after this year's is expected early in 2020, Beggan said. You can read more about the WMM here.
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