Unlike the geographic North Pole, which has a fixed location, the position of the magnetic North Pole is determined by the Earth’s magnetic field, which is constantly moving. In recent decades, the movement of the North magnetic field has been unprecedented – it has accelerated dramatically, then slowed down rapidly – and scientists cannot explain the cause behind the unusual behaviour of the magnetic field. In any case, the magnetic North Pole is now closer to Siberia than it was five years ago and continues to move towards Russia, CNN reports.Global positioning systems, including those used by planes and ships, find magnetic north using the World Magnetic Model (WMM) , as it was called in 1990. Developed by the British Geological Survey and the US National Oceanic and Atmospheric Administration (NOAA), this model notes the established position of magnetic north and predicts the future deviation based on the trajectory over the past few years. To maintain the accuracy of GPS measurements, every five years researchers revise the WMM, re-establishing the official position of magnetic north and introducing new predictions for the next five years of drift, writes News.ro.”The longer you wait to update the model, the larger the error becomes,” said Dr Arnaud Chulliat, senior research scientist at the University of Colorado, Boulder, and NOAA’s National Centers for Environmental Information. “The way the model is built, our forecast is largely an extrapolation, given our current knowledge of the Earth’s magnetic field,” the professor explained.Scientists released two models on 17 December: the standard WMM model, with a spatial resolution of about 3,300 kilometres at the equator, and the first high-resolution model, with a spatial resolution of about 300 kilometres at the equator.IMPLICATIONS FOR AVIATION AND ARMYWhile anyone can use the more powerful high-resolution model, most GPS equipment used by the general public incorporates the standard WMM and is not equipped to handle the other – and many users will not benefit from the upgrade, said Dr. Dr William Brown, a geophysicist and geomagnetism researcher at the British Geological Survey.”The major airlines will have to update the navigation software on their entire fleet of aircraft to load the new model, and the NATO militaries will have to update the software on a huge number of complex navigation systems on all types of equipment,” Brown explained to CNN. But for most people, the change is unnecessary. “Think of it like upgrading your smartphone – you don’t necessarily want to buy a new phone just to update an app to a new version that’s more powerful,” he said.The switch to the new model should be a seamless transition for GPS users; with the update, scientists have been checking the accuracy of the previous model’s predictions of where magnetic north will arrive by 2025, Chulliat said. “The predictions were very good,” he said. “And so the new model confirmed that we weren’t very far off.”WHY THE MAGNETIC NORTH DOESN’T STAY IN THE SAME PLACEAt the top of the world, in the middle of the Arctic Ocean, is the geographic North Pole, the point where all the lines of longitude that circle the Earth from top to bottom converge north. Marking the North Pole is a challenge because it is covered by moving sea ice, but its geographic location, also known as the true North Pole, is fixed.By comparison, the magnetic North Pole is the northernmost point of convergence of the Earth’s magnetic field, also known as the magnetosphere. Generated by the mixing of molten metals in the Earth’s core, the magnetosphere protects the planet from harmful solar radiation and prevents solar winds from destroying the Earth’s atmosphere.Because convective stirring in the Earth’s core never stops, the magnetosphere is never static. British explorer Sir James Clark Ross discovered the magnetic North Pole in 1831 in northern Canada, 1,609 kilometres south of the true North Pole. We now know that every day, the magnetic north follows an elliptical path of about 120 kilometres.Since its discovery, the magnetic north has moved away from Canada and towards Russia. By the 1940s, magnetic north had moved northwest from its position in 1831 by about 400 kilometres. In 1948, it reached Prince Wales Island, and in 2000 it left Canadian shores.”Over the last 400 years it has been moving at about 10 kilometres a year or less,” said Brown.UNUSUAL ACTIVITYHowever, the latest WMM update follows a period of highly unusual activity for the magnetic north pole. In 1990, its northward drift accelerated, increasing from 15 kilometres per year to 55 kilometres per year, Chulliat said. The drift “was unprecedented in terms of the records we have,” he added.Around 2015, the drift slowed to 35 kilometres per year. The rapid deceleration was also unprecedented, Chulliat said. By 2019, the fluctuations had deviated so much from the previous pattern that scientists updated the WMM a year earlier.Scientists expect the drift to Russia to continue to slow, although there is some uncertainty about how long the slowdown will persist and whether it will continue at the current pace, according to Brown. “It could change (its pace) or even accelerate again,” Brown said. “We will continue to monitor the field and evaluate the performance of the WMM, but we do not anticipate the need to release a new model before the planned 2030 update,” the scientist said.WHAT HAPPENS WHEN MAGNETIC POLES INVERSE?Earth’s magnetic field has behaved even more dramatically in the past, with the magnetosphere weakening so much that its polarity has reversed. This reverses the north and south magnetic poles, and the change can last tens of thousands of years.Scientists have estimated that this polar reversal, which can last for thousands of years, occurs once every million years, although the time between reversals has varied widely – from 5 000 years to 50 million years.The signs that precede such changes are also not well understood, making them difficult to predict, Brown points out.The last major reversal occurred about 750,000 to 780,000 years ago.During a polar reversal, animals that migrate using the magnetic field to find their way, such as whales, butterflies, sea turtles and many species of migratory birds, could be affected.A reversal would disrupt radio communications and jam navigation systems. Orbiting satellites would be at risk, as a weakened magnetic field would offer less protection against space weather.Although life on Earth has gone through several magnetic reversals over more than 100 million years, “we have never experienced a reversal since modern technology has been around,” Brown points out. “It would certainly be an exciting time for engineers to adapt our technology, but hopefully it will be a time when they would have to prepare slowly, over centuries, rather than a sudden change,” the researcher added.
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