Magnetic North has never been at one point. Over the past hundred years the direction of the compass arrow has steadily shifted to geographical North, driven by a liquid core of the Earth, located around 2880 km below the surface.
However, in recent years, scientists noticed something unusual: routine magnetic pole movement gained momentum, forcing him to jump for the Northern hemisphere — and no one can explain exactly why.
The change became so noticeable that scientists have started working on an emergency update to world magnetic model, a mathematical system that lays the Foundation for navigation, cell phones and ships to commercial airlines.
Update world magnetic model was released Monday, and the North magnetic pole may again be accurately determined for people around the world.
There are still many questions: why is the magnetic North pole changes its position so quickly? What were the consequences of delays in the updating of the data?
What is the world magnetic model?
James Clark Ross first discovered the magnetic North pole in 1831, on scattered Islands in the canadian territory of Nunavut. Since then the pole has largely moved North, breaking hundreds of kilometers over the past few decades. (Curiously, his polar opposite, magnetic South pole, almost did not move during this time.)
To keep up with all these changes, National oceanic and atmospheric administration and U.S. geological survey have developed the so-called “world magnetic model”.
The model is updated every five years, the last time was in 2015. Between each update, scientists check the accuracy of the model according to ground-based magnetic observatories and the Swarm mission of the European space Agency’s trio of satellites for mapping magnetic fields that are orbiting the Earth. Still it was enough to keep up with the movement of the North magnetic pole toward Siberia.
In the mid-1900s years, the North magnetic pole moved at a distance less than 30 meters every day. But in the 90s things began to change. By early August, the magnetic North pole was moving at a speed of 55 kilometers per year.
By the beginning of 2018, the scientists realized that soon the model will be violated allowable limits for magnetic navigation. Something had to be done before the next regular update of the model, scheduled for 2020.
What has been done.
To fix the model, scientists from NOAA and BGS modified it, using the latest data for three years. This updated version was pre-released online in October 2018.
However, the government shutdown, the U.S. detained a comprehensive public disclosure of information, which includes online calculators, software, and technical description of the changes. In principle, everyone who uses magnetic navigation, can benefit from this update, says Arno Chulliat, Geomagnetism from the University of Colorado at boulder and the branch of NOAA that worked on the update.
This model has been included in many of our modern mapping systems, including Google and Apple. But for most people the difference is negligible, and the changes are confined to latitudes above 55 degrees.
“The normal user is not affected too much, unless he was Hiking in the Arctic,” says Arno.
What caused these changes?
Interest in this process involves not only mapping. The dance of the lines of Earth’s magnetic field represents one of the few Windows in which scientists observe the processes happening thousands of kilometers under your feet.
The magnetic North pole, apparently is controlled by two areas of magnetic field: one under the Northern Canada and one beneath Siberia. Historically, the Northern part of Canada was stronger, holding the magnetic pole in their “hands.” But lately this has changed.
“Siberia looks like winning the battle,” says the researcher. “It’s kind of the attraction of the magnetic field along the direction from the geographical North pole”.
According to him, this may be a result of the weakening of the magnetic field under Canada. But he warns from having to make any certain conclusions.
What happens to the magnetic North pole?
“It’s hard to predict what will happen with the North magnetic pole, and whether it will maintain your speed, until you finish the movement in the direction of Siberia”, — said Robin Fiore, a researcher from Natural Resources Canada. “The only thing we are sure is his unpredictability”.
The rocks contain the geological maps even more strange movements of the magnetic poles, which suggests that over the last 20 million years the magnetic poles North and South several times changed places. It seems to be happening about every 200 000 — 300 000 years. The exact causes of these changes remain uncertain.
“There is no indication that will happen soon the reversal of the poles,” says Fiori. “And even if reversal happens, the geological record shows that this process takes several thousand years.”
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