Magnetic declination (the angle between magnetic and geographic north) in 2025 according to WMM2025.Red is magnetic north to east of geographic north; blue is to west.
BGS © UKRI and © Wessel, P., and W. H. F. Smith (1996), A global, self-consistent, hierarchical, high-resolution shoreline database, J. Geophys. Res., 101(B4), 8741–8743, doi:10.1029/96JB00104 (v2.3.6)
From BGS
Release of major upgrade
to a new model tracking magnetic north prompts global reset of satellite
tracking systems across trade and passenger transport routes.
Hundreds of thousands of mariners, airline operators and North Pole-based gift distribution specialists will be rushing to update their navigation systems after the launch of a new model tracking magnetic north, which is crucial to the accuracy of global positioning systems (GPS) that are relied upon across the world.
In partnership with the UK Defence Geographic Centre and the US National Geospatial-Intelligence Agency (NGA), BGS and the US National Oceanic and Atmospheric Administration (NOAA) have teamed up to update the World Magnetic Model (WMM).
The WMM is the standard model used by the United Kingdom and the United States governments, including the U.S. Federal Aviation Administration and the U.S. Department of Defense, as well as organizations with an international remit such as the North Atlantic Treaty Organization (NATO), the International Hydrographic Organization and the UK Hydrographic Office.
The model comprises a series of magnetic field maps that track changes in the magnetic field, such as the spot at which compass needles point in the northern hemisphere.
To ensure pinpoint accuracy, it is crucial that the shifts in magnetic north, which are caused by flow of the liquid iron in the outer core of the Earth, are taken into account in the electronic equipment that is trusted to guide global trade and enable the safe transit of travellers across the planet.
From GPS-enabled mobile phones to nuclear submarines, this improved resolution update will allow navigation with more accuracy than ever before to take place in the run up to Christmas — vital for all those who do not have a red nose to follow.
The WMM is officially released today, ensuring users can have the most up-to-date information so they can continue to navigate accurately for the next five years.
The current behaviour of magnetic north is something that we have never observed before. 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, which is the biggest deceleration in speed we’ve ever seen.
Dr William Brown, global geomagnetic field modeller at BGS.
While each model predicts how magnetic north will shift over the five-year period to limit any error, the change will have an impact on travellers.
Magnetic north pole locations from 1590 to 2030. BGS © UKRI and © Wessel, P., and W. H. F. Smith (1996), A global, self-consistent, hierarchical, high-resolution shoreline database, J. Geophys. Res., 101(B4), 8741–8743, doi:10.1029/96JB00104. (v2.3.6).
Imagine someone was planning to travel by sleigh from a chimney top in South Africa to a snow covered-roof in the UK, a journey of around 8500 km. Using the previous WMM and setting off just one degree off-course, he would end up approximately 150 km away from where he should[1].
With a margin of error of only a few inches between chimney flues, this could cause significant issues.
Values from the updated model can now be calculated, and the WMMHR2025 and the WMM2025 are available for download.
Values from the updated model can now be calculated, and the WMMHR2025 and the WMM2025 are available for download.
Links :
- BGS : WMM 2025
- NOAA : WMM 2025
- GeoGarage blog : Earth’s magnetic North Pole moving closer to Russia: implications and insights
- / World Magnetic Model updated / World Magnetic Model 2020
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