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If you use your smartphone to navigate, your system just received a crucial update. Scientists have published a new model tracked the position of the magnetic north pole, revealing that the pole is now closer to Siberia than it was five years ago and continues to drift towards Russia.
Unlike the geographic North Pole, which marks a fixed location, the position of the magnetic north pole is determined by the Earth’s magnetic field, which is in constant motion. Over the past few decades, the movement of magnetic north has been unprecedented – it accelerated dramatically, then, more recently, it rapidly slowed – although scientists cannot explain the underlying cause of the behavior unusual magnetic field.
Global positioning systems, including those used by aircraft and ships, find magnetic north using the World Magnetic Model, as it was named in 1990. Developed by the British Geological Survey and the National Oceanic and Atmospheric Administration, this model notes the established position of the magnetic field. northward and predicts future drift based on the trajectory of recent years. To preserve the precision of GPS measurements, every five years, researchers revise the WMMresetting the official position of magnetic north and introducing new predictions for the next five years of drift.
“The longer you wait to update the model, the more the error increases,” said Dr Arnaud Chulliatsenior research scientist at the University of Colorado Boulder and NOAA’s National Centers for Environmental Information. “The way the model is constructed, our predictions are primarily an extrapolation given our current knowledge of the Earth’s magnetic field.”
Scientists released two models on December 17: the standard WMM, with a spatial resolution of about 2,051 miles (3,300 kilometers) at the equator, and the first high-resolution model, with a spatial resolution of about 186 miles (300 kilometers) to the equator. equator. Even though everyone can use the most powerful high-resolution model, most GPS hardware 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. level, said Dr. William Browngeophysicist and geomagnetism researcher at the British Geological Survey, in an email.
“Major airlines will upgrade the navigation software of their entire aircraft fleets to carry the new model, and the NATO military will have to upgrade the software of many navigation systems complex on all types of equipment,” Brown told CNN. But for most people, this change isn’t necessary.
“Think of it like upgrading your smartphone: You don’t necessarily want to buy a new phone just to upgrade an app to a new, more powerful version,” he said.
The move to the new model should be a smooth transition for GPS users; With this update, scientists verified the accuracy of the previous model’s predictions about where magnetic north would be by 2025, Chulliat said.
“The forecast was very good,” he said. “The new model therefore confirmed that we were not very far from it. »
But why are all these updates necessary and why doesn’t magnetic north stay in the same place?
At 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 run around the Earth from top to bottom converge to the north.
Marking the North Pole is challenging because it is covered in moving sea ice, but its geographic location, also known as the true North Pole, is fixed.
In comparison, the North Magnetic Pole is the northernmost point of convergence of Earth’s magnetic field, also known as the magnetosphere. Generated by the churning of molten metals in The core of the Earththe magnetosphere protects the planet from harmful solar radiation and prevents solar winds from destroying the Earth’s atmosphere.
Because convective motion in the Earth’s core never stops, the magnetosphere is never static. As a result, its northernmost point is always moving.
British explorer Sir James Clark Ross discovered the magnetic North Pole in 1831 in northern Canada, approximately 1,609 kilometers south of the true North Pole. We now know that each day, magnetic north traces an elliptical path of approximately 120 kilometers.
Since its discovery, magnetic north has moved away from Canada and toward Russia. By the 1940s, magnetic north had moved northwest from its 1831 position by about 250 miles (400 kilometers). In 1948 he reached Prince Wales Island, and by 2000 he had left Canadian shores.
“It has generally moved about 10 km (6.2 miles) per year or less over the past 400 years,” Brown said.
However, the latest WMM update follows a period of very unusual activity for the magnetic north pole. In 1990, its northward drift accelerated from 9.3 miles (15 kilometers) per year to 34.2 miles (55 kilometers) per year, Chulliat said. This change “was unprecedented based on the records we have,” he added.
Around 2015, the drift slowed to about 21.7 miles (35 kilometers) 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 toward 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 rate, 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 needing to release a new model until the planned update in 2030.”
The Earth’s magnetic field behaved even more dramatically in the past, with the magnetosphere weakening so much that its polarity was 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 take thousands of years, occurs about once every million years, although the time between reversals varies greatly – from 5,000 years to 50 million years. ‘years. The signs that precede such reversals are also not well understood, making them difficult to predict, Brown said. The last major turnaround occurred around 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 rollover would disrupt radio communications and jam navigation systems. Orbiting satellites would be at risk because a weakened magnetic field would provide less protection from space weather.
Although life on Earth has undergone multiple magnetic reversals over more than 100 million years, “we’ve never experienced a reversal when modern technology was present,” Brown said.
“It would certainly be an interesting time for engineers to adapt our technology to, but we hope they will have to prepare for it slowly and over centuries, rather than through a sudden change.”
Mindy Weisberger is a science writer and media producer whose work has appeared in Live Science, Scientific American, and How It Works magazines.