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Earth's magnetic north pole has shifted towards Siberia, as predicted and shown in the latest 5-year update to the World Magnetic Model (WMM).
The WMM is jointly developed by NOAA and the British Geological Survey (BGS).
"Magnetic north has been moving slowly around Canada since the 1500s but, in the past 20 years, it accelerated towards Siberia, increasing in speed every year until about five years ago, when it suddenly decelerated from 50 to 35 km per year."
Maps like these, published by the BGS and NOAA show the magnetic declination, the angle between magnetic and geographic north, at various points on earth, depicted as an isoclinic map of equal inclination value contours.
E.g., along points on the green line, the magnetic inclination is zero, i.e., magnetic north lies in the direction of the geographic north.
https://www.ncei.noaa.gov/news/world-magnetic-model-2025-released
https://www.ncei.noaa.gov/products/world-magnetic-model
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Earth's magnetic field is generated by the convective movement of its ~2,250 km thick outer core, composed of molten iron and nickel.
Heat is generated by potential energy released by heavier materials sinking toward the core and by decay of radioactive elements.
The heat creates convection currents in the molten metal, which are organized into rolls by earth's rotation and the Coriolis force. This creates electric currents which generate the magnetic field.
@AkaSci@fosstodon.orgEarth's magnetic field is useful for lot more than navigation by humans and various organisms. It is responsible for sustaining life on earth.
Earth's magnetic field extends several 10s of 1000s of km into space, creating the magnetosphere, which protects Earth from the charged particles of the solar wind and cosmic rays that would otherwise strip away the upper atmosphere. Mars lost most of its atmosphere after its magnetic field shut down.
https://en.wikipedia.org/wiki/Magnetosphere
https://science.nasa.gov/science-research/earth-science/earths-magnetosphere-protecting-our-planet-from-harmful-space-energy/
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Given the dynamic origin of earth's magnetic field, its strength, direction and polarity change over time.
It has reversed polarity 183 times in the last 83 million years. The time intervals between reversals have fluctuated widely, but average about 300,000 years, with the last taking place about 780,000 years ago.
Polarity reversals have had little effect on the magnetosphere or on life on earth. However, Its effect on modern civilization may be non-negligible.
“Geomagnetic excursions” are shorter-lived but significant changes to earth's magnetic field. Excursions happen about 10 times as often as pole reversals.
The well-studied Laschamps event between 42K and 41K years ago, caused Earth's magnetic pole to drift south and decline in strength to ~5% of its current strength.
The weakening of the magnetosphere is claimed to have contributed to the extinction of Australian megafauna and the extinction of the Neanderthals.
The shifting direction of earth's magnetic field also affects airport runway numbering!
The runway number is between 1 and 36 = round(z / 10), where z is the magnetic azimuth of the runway in degrees. E.g., runway number 33 points between 325° and 335° towards mag NW.
In 2009, the Fairbanks International Airport in Alaska renamed runway 1L-19R to 2L-20R, when magnetic north shifted enough to mandate a change.
Now imagine a large excursion or polarity reversal 
https://www.faa.gov/air_traffic/publications/atpubs/aim_html/chap2_section_3.html
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@AkaSci interesting. Did not know that
@AkaSci 180 degree field change is not a problem for runway numbering. It is for a lot of other things, but not that.
@vinknie
Do keep in mind that a mag field polarity reversal is not always close to 180° in magnitude; it could be 150° or 170°.
Now imagine the amount of paint and paintwork needed across airports around the world 
But as you are implying, that is a minor inconvenience compared to other issues the world with face with a polarity reversal.
@AkaSci Heh, sounds like a supervillain world domination plan, conquer the world by paint.
But why do they stick to magnetic north anyway?
@AkaSci Northern Canada uses true north instead of magnetic north, because the pole moves too much
@jonathankoren
Thanks for the info!
@AkaSci @minkorrekt was machen die Hunde beim kacken nun? Passen die sich mit an? Ernstgemeinte Frage... ;-)
@AkaSci "Polarity reversals have had little effect on ... life on earth".
That's a bit surprising given the continued discovery of ever yet more organisms using magnetic field navigation.
Otherwise, disproportionate population declines during polarity changes would be a great indicator as to how pervasive magnetic field navigation truly is.
One presumes that navigation is merely augmented or that organisms adapted quickly enough.
@AkaSci Which raises the question as to how long a reversal takes.
You say they occur on average every 300,000 years, but is the reversal a relatively linear transition spanning much of this time period or does it flip relatively quickly and then stay in that orientation for much of the time period?
@AkaSci This part is actually wrong. There is no evidence for the magnetic field to be "responsible for sustaining life".
The fact that Mars lost its atmosphere cannot be extrapolated to Earth, because Earth's gravity is much larger, and probably enough to keep an atmosphere for a very long time without magnetic field.
What actually protects us from charged particles is the atmosphere. That's why in an airplane you're subjected to more radiations than on ground.