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The magnetic North Pole is tireless.
Unlike the geographic North Pole, where the lines of longitude meet at the top of the planet, the magnetic pole is the point the compbad recognizes in the north. For the moment, it is four degrees south of the geographic pole, which lies in the Arctic Ocean, 90 degrees to the north.
But that was not always the case.
In the mid-19th century, the magnetic north pole was much farther south in the Canada region. However, for 150 years, the North Pole has moved from Canada to Siberia.
This change of address can not be ignored because magnetic compbades still serve as a basis for modern navigation, for aircraft systems. Civil and military forces to guide the iPhone
In 1965, scientists launched a mathematical representation based on Earth's magnetic field data to better track the constant change in pole address. The global magnetic model is updated every five years – the latest update is from 2015 – as the magnetic field is constantly changing.
By the beginning of 2018, it was clear that the 2015 edition was not working because the pole's progress in the Siberian direction has picked up speed, which makes the system and some navigation systems incorrect.
For this reason, scientists first updated the model before the deadline; the new model was released late Monday (4). With work completed in the midst of the partial closure of the US government (which delayed its launch), researchers are still trying to understand the mysteries of the inner core of the Earth that must be at the root of the pole's surprising behavior. magnetic.
The magnetic north pole was discovered nearly 400 years ago when the English mathematician Henry Gellibrand realized that in the previous 50 years the magnetic pole had approached hundreds of kilometers from the geographic pole position.
"It was an important perception., Monumental, that the field was not static, but dynamic," said Andrew Jackson, geophysicist at ETH Zurich University.
However, the magnetic pole did not take long to change direction and move away from the fact that the field is not only dynamic but unpredictable.
"The problem we are still facing today is that we do not have a good pattern to predict how the field will change," Jackson said.
Scientists began to follow the magnetic field in its constant mutation. The first magnetic charts, drawn by explorers on exploratory voyages, revealed that for two centuries, magnetic north was along many islands and cbads of the Arctic Archipelago.
Then, around 1860, he turned abruptly and shot towards Siberia. Since then, the magnetic north pole has traveled nearly 2,400 kilometers and has recently positioned itself in the middle of the Arctic Ocean, still on the way to Russia.
Scientists attribute this love of movement to the movement of liquid iron in the outer core of the planet. Iron fluctuates – it increases in temperature, down and down. And this movement drives the Earth's magnetic field and produces the described changes.
To more accurately map these changes, scientists developed the global magnetic model nearly 55 years ago, initially in the form of interstate collaboration. United States and United Kingdom
The map that we know today exists in its current form since 1990 and was created by an agency of the NOAA (United States) and the United States. British Geological Survey (BGS), the British Geological Survey Service. The map is produced at the request of American and British military agencies and used by many other armed forces around the world.
In addition to the GPS satellite positioning system, navigation systems used by satellites, planes, ships, submarines and other vehicles. rely on magnetic compbades to make sure they are heading in the desired direction. The most visible sign of the system may be the large white numbers painted at the end of each lane of the airport, reflecting its magnetic orientation.
But as the planet's magnetic field changes, orientation and clues change. identification number. In a few months, for example, the runways at Dwight Eisenhower National Airport in Wichita, Kansas, will receive new designations reflecting the change in magnetic orientation. The process – which involves repainting runway identification numbers and replacing signs – will likely cost hundreds of thousands of dollars
and it all depends on the global magnetic model. Keeping it up-to-date is not easy. Unlike the kilogram or the second, the magnetic field can not be defined once and then used for decades.
"The magnetic field is constantly changing," said Susan McLean, retired director of the NOAA Division of Geophysical Sciences, who will mount the magnetic model in the past. "It changes over time, with location and with changes." Tracking the planet's magnetic field, he says, is like predicting weather
And as with weather forecasts, it is quite impossible to predict with certainty where the pole will move. But scientists can approach accurate forecasts based on much of the data collected by satellites and ground observatories. The data allow them to infer the evolution of the magnetic field in recent years and to extrapolate future changes based on a model that, hopefully, will remain stable for the next five years.
The Pilgrimage of the Pole
Scientists unveiled the 2015 global magnetic model and periodically checked it based on field station measurements to ensure that magnetic field variations terrestrial were accurately predicted. "We realized that the error in the Arctic was increasing faster than expected," said Arnaud Chulliat, geophysicist at the University of Colorado at Boulder and at the University of Colorado at Colorado. Springs. NOAA.
Although the North Magnetic Pole has been moving from Canada to Siberia for a long time, the pace of this movement is changing radically. For much of the twentieth century, the displacement was of the order of 10 kilometers per year. In the 80s, the movement was growing and in 2000, the change of position was annually 56 km between Canada and Siberia.
Thus, in 2015, the shift of the pole had been reduced to only 50 km. per year When this year's global magnetic model was released, scientists predicted that the speed of travel would continue to decline – but that's not what happened.
Shortly after the launch of the model, the magnetic north pole regained momentum and now travels at about 56 kilometers per year. At the end of 2017, he crossed the international line of the date and entered the Eastern Hemisphere.
"It's not the fact that the pole moves is causing trouble, but the fact that it's accelerating at this rate," said William Brown, a geophysicist at BGS. "The greater the acceleration or deceleration, the more difficult it is to predict where the thing will be."
And that means the current model is incorrect – at least in the Arctic.
time – at the top of the planet, some international airline flights pbad near the geographic North Pole.
If you used the current model to go to the magnetic north pole, you would reach a position 40 kilometers from the actual pole.
Therefore, scientists have tried to repair the model carrying it with several years of recent data. Together, BGS and NOAA have released a new version. But efforts to complete the review of publicly available online systems run by NOAA have been delayed by the partial shutdown of the US government. The researchers were able to finish the update on Monday.
Public maps will have many uses, from recalculating airport runway designations to ensuring that the US Department of Defense systems are properly installed. "
But for most people living in low and middle latitudes, the current model is safe.
" south of 65 degrees north and outside of Canada, the average user will see little difference in their daily lives, "said Ciaran Bergan, BGS Geophysicist.
Geomagnetic Apocalypse? Probably Not
With the improvements now complete, scientists are eager to understand the causes of the rush. polo in Siberia. "It is clear that something strange happens," said Phil Livermore, geophysicist at the University of Leeds in England.
Several times, during From the Earth's long history, the magnetic field has been considerably weakened.The magnetic north pole slid toward the southern part of the planet as the magnetic south pole rose.The process took a few thousand years. years and, once the Intensity of the magnetic field returned to normal, it had reversed.
The recent pole shift as well as other changes – such as a weakening of the Earth's magnetic field – have led some scientists to imagine if a flip-flop like this could be envisioned.
"What we have satisfied with some aspects of magnetic reversal," said Courtney Sprain, geophysics at the University of Liverpool in England. But, she adds, "we definitely can not say for sure"
Most scientists, including Sprain, doubt about an imminent geomagnetic reversal. For starters, although the North Magnetic Pole seems to be moving, this is a regional rather than global phenomenon.
Livermore, for example, estimates that there are two large magnetic structures in the outer core of the planet, one under Canada and the other under in Siberia.
Second, although the Earth's magnetic field weakens, many experts say that it continues to be more powerful than the long-term geological mean.
Peter Olson, a geophysicist from Johns Hopkins University, believes that the current changes reflect a transient fluctuation rather than a reversal.
"It's the badogy between a stock market correction and a global depression," he said. "How do we know that the stock market is not about to sink into a global depression, a crash?" That might well be the case – but it's more likely that it will work. of a correction and that she is recovering. "
The magnetic field was about to reverse, scientists argue that it is not an apocalyptic scenario. Although the field provides essential protection against strong solar radiation, the fossil record does not reveal mbadive extinctions in previous setbacks.
And whatever the risks to the energy and communication networks, humanity would have ample time to "
" Of all the problems we have, it is not part of the top 10 ", said Olson
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