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The North Pole no longer wanders - it runs
#7
(01-30-2019, 07:18 AM)Rumata Wrote: Gentlemen,  below is the translation from German into English of some interesting fact. Hope, you will find it  useful. The translation of the article in the following post was  done by Google, therefore there are quite a few  strange sentences.  But I hope the main content is decipherable.


Magnetic field shiftThe North Pole no longer wanders - it runs
The magnetic field of the earth always seems to be constant. But in truth, it's changing so fast that researchers have to act now.
 
JAN BERNDORFF
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The magnetic north pole moves from Canada to Siberia. GRAPHICS: NATURE / TSP / BÖTTCHER

January 30, geophysicists from the United States and the United Kingdom have decided to take an unusual, world-wide step: prematurely update the World Magnetic Model. If they did not do it, pilots, ship captains, and even Google Maps users would soon stupidly look out of bed if their GPS ever fails.
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This has to do with the cause of the magnetic field: it is caused by movements in the interior of the earth. From the solid, up to 5000 degrees hot core of iron and nickel heat rises and leads in the outer, liquid core, which is also largely made of iron, to convection currents. Material penetrates outward, cools down again and sinks back into deeper layers. Because of the earth's rotation, there are also lateral movements. And because the material is electrically conductive, it forms the magnetic field around our home planet.
Since the 90s, the North Pole has been traveling 50 kilometers a year


"The circulation can be imagined as boiling water in a pot," says Achim Morschhauser, research associate at the geomagnetic observatory Niemegk of the German Research Center for Geosciences (GFZ) in Potsdam. "The heat rises from below and keeps everything moving, and the magnetic field lines are coupled to these movements, and like spaghetti that you throw into the boiling water, they are constantly being moved."
It is a dynamic system with many irregularities, in which movements alternate again and again with countermovements. In extreme cases, there is even a complete reversal: the magnetic north pole then becomes the south pole and vice versa. Strictly speaking, the North Pole is actually a South Pole in magnetic terms. On average, this occurs every 250,000 years, as revealed by analyzes of magnetized iron particles in old rock layers. The last umpolung of the earth is already 780.000 years ago - the next one appears overdue.
Perhaps the rage of the North Pole is even a harbinger for it. While traveling ten to fifteen kilometers a year during the twentieth century, traveling from northern Canada relatively straightforward across the Arctic Sea to eastern Siberia, he has accelerated to more than 50 kilometers per year since the 1990s. But that does not have to be reversed. Some researchers also believe that the cause of his haste is a horizontal stream of liquid iron more than 400 kilometers wide, which was discovered 3,000 years ago by Canada and Russia two years ago and is traveling Europe at a good 40 kilometers per year - three times faster than the material usually flows in the outer core.
Little is known about the interior of the earth
"Theoretically, the pole can also change its direction of movement at any time, as it did several times in the 19th century," says Achim Morschhauser. "That's the problem: we do not know enough about the convection currents in the Earth's core to anticipate such effects."
Actually, research on the interior of the earth is still less known than that of the sun. Similarly unforeseen, so-called geomagnetic impulses can occur, comparatively sudden peaks in the circulation in the earth's core. Like particularly large blubber bubbles in the saucepan, these outbreaks cause severe disturbances of the Earth's magnetic field.


Other distortions are of longer duration: Already for nearly 200 years - Alexander von Humboldt noted that - we know that the magnetic field over the South Atlantic, including South America and South Africa, is particularly weak. Satellites that fly over this region - but also living beings on the ground - are thereby exposed to increased radiation from space. Experts call this the "South Atlantic Anomaly". Like the acceleration of the North Pole, it could also announce a reversal in polarity . But she does not have to. Often, the magnetic field has recovered from such periods of weakness.
Normally, the model is updated only every five years
In any case, such effects cause geophysicists to prematurely update their model . Usually they do this every five years: the model describes the current state and calculates how the field evolves in the following years - where, for example, the North Pole will move. To do this, the researchers use data from satellites and terrestrial observatories scattered around the globe.
"But the forecasts are linear," says Morschhauser. "If there is a short-term anomaly in between, the forecast is wrong." For example, in 2016, just a year after the researchers last updated their model, there was a strong geomagnetic impetus in South America that diverges from actual forecasting. "Since then, the error has become bigger and bigger," says Arnaud Chaulliat of the University of Boulder Colorado, who works on the world magnet model, the journal " Nature ".
more on the subject

Swarm ofsatellites"Swarm" is to measure the weakening magnetic field

[img=225x0]https://www.tagesspiegel.de/images/heprodimagesfotos87120131121swarm_constellation-jpg/9104952/2-format3010.jpg[/img]
[url=https://www.tagesspiegel.de/wissen/satellitenschwarm-swarm-soll-schwaechelndes-magnetfeld-vermessen/9104940.html]
Ralf Nestler

Now the threshold of tolerance has been reached. The leaders of the world magnet model must act. Otherwise, the deviations in the navigation become so great that a pilot from the USA would land in Luckenwalde on a transatlantic flight by compass bearing rather than in Berlin.


Is this from a reliable source? Because it is, for the most part, alarmist nonsense.
The earth's magnetic field is in a constant state of flux. This is well understood and not surprising. There is no reason for the axis of the earth's magnetic field to align with its axis of rotation - if it ever has or ever does it is by pure coincidence. Whilst the rate of change cannot be accurately predicted, it is known and understood and aircraft will not fall out of the sky, or get lost on their way to Berlin, as a result of a degree's change every few years.
Navigational charts of a particular area report the magnetic variation at that location for the year of publication, along with an estimate of rate of change. Clearly this estimate is based on past experience so cannot be used ad infinitum; if you are using a chart more than a few years old you will need to update the correct value of variation from other sources - the almanac downloaded to your GPS is one such - but even in the absence of such up to date information, the difference between the actual variation and that predicted from the old chart information is unlikely to be if any great significance, particularly as your compass is likely only graduated in 5º increments and your helmsman unable to steer within 10º!

Oh - and neither are compasses rendered useless by southern hemisphere dip.
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RE: The North Pole no longer wanders - it runs - by jeremyparker - 08-15-2019, 06:35 AM

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