The World Magnetic Model 2025 (WMM2025) has been released, providing an updated prediction of Earth’s magnetic fields. This model will remain valid until late 2029, during which the magnetic north pole is expected to continue its slow drift toward Russia. The release underscores the importance of monitoring the magnetic north pole’s unpredictable movement and its implications for navigation systems.
Earth’s magnetic north pole differs from the geographic North Pole. While the geographic North Pole, or “True North,” is a fixed location at 90° North latitude where the Earth’s axis of rotation intersects its surface, the magnetic north pole is a dynamic point influenced by the movement of liquid metals in Earth’s outer core.
The outer core consists of conductive molten metals in constant motion, driven by Earth’s rotation and heat-induced convection. These movements generate electric currents that create Earth’s magnetic field, which features two poles. Unlike the fixed geographic poles, magnetic poles are constantly shifting, albeit slowly. This variability necessitates periodic updates to models like the WMM to ensure accuracy.
On December 17, the National Oceanic and Atmospheric Administration (NOAA) and the British Geological Survey (BGS) unveiled the WMM2025. This latest update includes the World Magnetic Model High Resolution (WMMHR2025), a significant enhancement in spatial resolution. At the equator, WMMHR2025 achieves a resolution of approximately 300 kilometers (186 miles), a marked improvement from the standard model’s resolution of 3,300 kilometers (2,050 miles).
The updated model is crucial for modern technology that depends on Earth’s magnetic field, such as the Global Positioning System (GPS) and other satellite-based navigation systems used worldwide.
The importance of this release is heightened by the accelerating movement of the magnetic north pole. Historically, the north magnetic pole has shifted approximately 2,250 kilometers (1,400 miles) across the Northern Hemisphere, traveling from Canada toward Siberia since the 1830s. Between 1990 and 2005, the rate of movement increased significantly, rising from less than 15 kilometers (9.3 miles) per year to around 50 to 60 kilometers (31 to 37 miles) annually.
Dr. William Brown, a global geomagnetic field modeler at BGS, emphasized the significance of the WMM2025 in a statement: “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.”
Dr. Brown further explained the unprecedented nature of recent magnetic north movements: “The current behavior 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 kilometers per year, which is the biggest deceleration in speed we’ve ever seen.”
The WMM2025 serves as a vital tool for understanding and adapting to these changes, ensuring navigation systems remain reliable despite the magnetic north’s erratic behavior