The north magnetic pole sits in the Arctic, and as of recent years it has crossed into the Eastern Hemisphere on a path toward Siberia, drifting at speeds that have at times exceeded 50 kilometers per year. That movement is driven by churning flows of liquid iron deep in Earth’s outer core, and the pole’s recent acceleration caught scientists off guard enough that the global model used for navigation had to be updated ahead of schedule. The story behind that drift involves the deepest layers of the planet, the satellites orbiting above it, and even the salmon swimming through its oceans.
Where the Pole Is Right Now
The north magnetic pole is not in the same place as the geographic North Pole. While the geographic pole is fixed at the top of Earth’s rotational axis, the magnetic pole wanders. For most of the twentieth century it sat in the Canadian Arctic Archipelago, drifting slowly. Over the past few decades that drift picked up dramatically, and the pole crossed the International Date Line, heading toward Siberia. Satellite observations confirm that both magnetic poles are on the move, but their speeds are wildly different. The north magnetic pole has been traveling at roughly 37 to 72 kilometers per year depending on the period measured, while the south magnetic pole creeps along at only about 5 to 9 kilometers per year.1Journal of Geophysical Research: Space Physics. The Location of the Earth’s Magnetic Poles From Circum‐Terrestrial Observations
That lopsidedness is itself interesting. If the magnetic field were a perfectly symmetric bar magnet, both poles would move at similar rates. The fact that they don’t tells us the field’s internal structure is more complicated than a simple dipole, shaped by uneven flows thousands of kilometers beneath our feet.
What Generates the Field in the First Place
Earth’s magnetic field originates in the outer core, a shell of molten iron roughly 2,200 kilometers thick that sits between the solid inner core and the rocky mantle above. Convection in that liquid metal, driven by heat escaping from the inner core and by the solidification of iron onto its surface, creates electric currents. Those currents generate magnetic fields, which in turn influence the fluid motion, sustaining the whole system in a feedback loop known as the geodynamo. Numerical simulations of this process have become sophisticated enough to reproduce a self-sustaining magnetic field that resembles the real one.2PubMed. Earth’s core and the geodynamo
The key point for understanding why the pole moves is that these core flows are not static. They shift, strengthen, and weaken over timescales ranging from years to millennia. Because the magnetic field is a direct product of those flows, any change in the pattern of convection reshapes the field at the surface, and the poles follow along.
Why the Pole Suddenly Sped Up
Through much of the twentieth century, the north magnetic pole drifted at a leisurely pace of around 10 to 15 kilometers per year. Then, starting in the 1990s, it accelerated sharply. Researchers traced the cause to changes happening at the boundary between the outer core and the mantle, specifically beneath the Arctic. A large shift in the radial magnetic field at the core surface, located under the New Siberian Islands, appears to be the main driver. That change occurs in a region where two patches of opposing magnetic polarity sit side by side, and their interaction is consistent with what simulations describe as a “polar magnetic upwelling,” essentially a rising plume of liquid iron that pushes magnetic flux toward the surface.3Journal of Geophysical Research: Solid Earth. Magnetic flux expulsion from the core as a possible cause of the unusually large acceleration of the north magnetic pole during the 1990s – Section: Abstract
The hypothesis is that this upwelling slowed during the 1990s, changing the balance of magnetic flux at the surface and pulling the pole toward Siberia. The analysis also suggests a significant role for magnetic diffusion in the region, meaning the field is not just being carried by flowing metal but is also spreading and reorganizing through the core fluid itself. This combination of flow changes and diffusion is what made the acceleration so pronounced.
Waves Inside the Core
The pole’s wandering is not the only evidence of restless activity deep below. Scientists have detected oscillations in the core with periods of several decades, inferred from long-term changes in the magnetic field measured at the surface. These oscillations are consistent with a type of wave called torsional oscillations, in which cylindrical shells of fluid in the core rotate back and forth. The internal magnetic field itself provides the restoring force, essentially acting like an elastic band that pulls the fluid back after it has been displaced.4Geophysical Journal International. Inversion of torsional oscillations for the structure and dynamics of Earth’s core
These waves matter because they give scientists a window into conditions inside the core that are otherwise impossible to observe directly. The speed at which torsional oscillations travel depends on the strength of the magnetic field deep in the core, so measuring the waves at the surface lets researchers work backward to estimate field strengths at depths where no instrument can reach. Changes in these oscillations can also contribute to jerks in the pole’s path, adding shorter-term wobbles on top of the longer drift.
How Scientists Keep Track
Tracking the magnetic pole used to mean sending expeditions into the Arctic with compasses and magnetometers. Today the job is done largely from orbit. The European Space Agency’s Swarm mission, a trio of satellites launched in 2013, continuously measures the magnetic field from about 490 kilometers above the surface. Researchers use the satellite data to construct what they call Geomagnetic Virtual Observatories: evenly distributed points around the globe where the field’s strength and direction are estimated from nearby satellite passes. These virtual observatories produce time series that let scientists monitor changes in the main field and its rate of change on monthly or four-monthly timescales.5Earth, Planets and Space. Geomagnetic Virtual Observatories: monitoring geomagnetic secular variation with the Swarm satellites
The satellite data feeds into mathematical models of the global field, the most widely used of which is the World Magnetic Model. Updated every five years (and sometimes more often), it provides the magnetic declination, inclination, and field strength at any point on the planet. The U.S. Department of Defense, the U.K. Ministry of Defence, NATO, and the International Hydrographic Organization all rely on it for navigation and heading systems, and it is embedded in countless civilian devices as well.6British Geological Survey. The US/UK World Magnetic Model for 2020-2025 When the north pole’s acceleration caused the model to drift out of acceptable accuracy before its scheduled 2020 update, an emergency out-of-cycle revision was released in early 2019. That was an unusual step and a sign of just how rapidly conditions were changing.
What Pole Movement Means for Navigation
Every compass needle points toward the north magnetic pole, not geographic north. The angular difference between the two, called magnetic declination, varies by location and changes over time as the pole moves. For casual hikers using a compass in the woods, the effect is manageable: declination values are printed on topographic maps and can be looked up online. But for systems that depend on precise magnetic headings, even small errors can compound. Military targeting, commercial aviation, maritime shipping, and directional drilling for oil and gas all use the magnetic field as a reference, and the World Magnetic Model is the agreed-upon standard that keeps them accurate.6British Geological Survey. The US/UK World Magnetic Model for 2020-2025
Airports occasionally have to renumber their runways because runway designations are based on magnetic heading. When the local declination shifts enough, the number painted on the tarmac no longer matches the compass reading a pilot sees on approach. This has happened at airports worldwide and will continue as the pole keeps moving. For most people, though, the practical impact is invisible: your phone’s mapping app automatically corrects for declination using the same World Magnetic Model data, so you never notice the pole has wandered.
The North Pole Versus the South Pole
The dramatic asymmetry in how the two magnetic poles behave deserves a closer look. As noted earlier, the north magnetic pole has been clocking speeds roughly five to ten times faster than the south pole.1Journal of Geophysical Research: Space Physics. The Location of the Earth’s Magnetic Poles From Circum‐Terrestrial Observations This is a direct consequence of the structure of the field at the core-mantle boundary. The field is not a clean dipole; it has strong regional anomalies, sometimes called flux lobes, that concentrate magnetic energy in certain areas. Changes in these lobes beneath the Arctic have been more vigorous in recent decades than changes beneath the Antarctic, which is why the north pole has been on the move while the south pole has been comparatively sluggish.
The lopsidedness also extends to the field’s overall strength. The magnetic field is weaker in some regions than others, and the South Atlantic Anomaly, a broad zone of reduced field strength stretching from South America to southern Africa, is one of the most studied examples. That anomaly is not directly caused by the south magnetic pole’s position, but it is part of the same picture: the internal structure of the core produces a field at the surface that is lumpy and uneven, not the neat dipole drawn in textbook diagrams.
Excursions and Reversals
The pole’s current wandering, as dramatic as it seems, is modest compared to what the geological record shows. Over Earth’s history, the magnetic field has completely reversed its polarity hundreds of times, with the north and south magnetic poles essentially swapping places. The last full reversal happened about 780,000 years ago. Between full reversals, the field sometimes undergoes excursions: short-lived episodes where the magnetic direction swings far from its usual orientation, sometimes approaching a fully reversed state, but fails to establish a stable reversed polarity before snapping back.7Geophysical Research Letters. Geomagnetic excursions: Knowns and unknowns The distinction between a reversal and an excursion matters because an excursion, even one that achieves a near-180-degree change in direction at many sites, is defined by its failure to hold the reversed state.8Geophysical Journal International. The distinction between geomagnetic excursions and reversals
Reversals take thousands of years to complete and are accompanied by a substantial weakening of the overall field strength. During a reversal, the simple two-pole structure breaks down, and the field can temporarily develop multiple poles scattered across the globe. The current acceleration of the north magnetic pole is not evidence that a reversal is imminent. The field has been weakening gradually for the past couple of centuries, but at its current rate of decline it would take well over a thousand years to reach zero, and weakening does not always lead to a reversal. Sometimes the field just recovers.
How Migrating Animals Cope
The magnetic field is not just a navigational tool for humans. Many animals, from sea turtles to birds to salmon, use the geomagnetic field to navigate across vast distances. For species that rely on inherited magnetic maps, the steady drift of the field poses a real challenge. A salmon that returns to spawn in a specific river needs its internal compass to match the magnetic landscape of its birthplace. But if the field has shifted over the years the salmon spent at sea, the coordinates no longer line up perfectly.
Research on Pacific salmon shows that geomagnetic drift is a significant factor shaping their migration routes. In one large analysis, drift of the magnetic field accounted for about 23 percent of the variation in homing migration routes for sockeye salmon and about 44 percent for pink salmon.9PubMed Central. Geomagnetic imprinting predicts spatio-temporal variation in homing migration of pink and sockeye salmon Those are substantial numbers, suggesting that geomagnetic navigation is not just a backup system but a primary mechanism for long-distance homing. The implication is that as the pole continues to move, migration patterns for salmon and potentially many other species will shift along with it.
Animals may mitigate the effects of field drift in several ways. One possibility is that they calibrate their inherited magnetic map against the field conditions they experience during early development, essentially updating the software to match the current hardware.10Integrative and Comparative Biology. Inherited Magnetic Maps in Salmon and the Role of Geomagnetic Change This recalibration could help each generation stay roughly on track even as the field changes between generations. But it has limits. If the field changes too rapidly or too unpredictably, the inherited map could become inaccurate enough to cause population-level disruptions in migration. Given the diversity of animals that use geomagnetic navigation, field drift may be a broader ecological force than most people realize.
The Cosmic Radiation Connection
Earth’s magnetic field does more than guide compasses and salmon. It also serves as a shield against cosmic radiation, the constant stream of high-energy particles raining in from the sun and from elsewhere in the galaxy. The field deflects many of these particles before they reach the atmosphere, and its effectiveness depends on field strength. Regions where the field is weaker, like the South Atlantic Anomaly mentioned earlier, already see slightly higher radiation levels at aircraft cruising altitude.
If the overall field were to weaken significantly during a pole shift or excursion, the shield would thin, potentially allowing more cosmic radiation to reach the surface. The practical consequences for most people would be minimal in the short term, since the atmosphere provides substantial additional shielding. But for astronauts, high-altitude pilots, and satellite electronics, a substantially weakened field would change the radiation environment enough to require adjustments. The current pole movement, while fast by historical standards, is not causing any measurable change in radiation exposure at ground level.
Why Prediction Is So Difficult
Forecasting where the north magnetic pole will be in 50 or 100 years is roughly as reliable as predicting the weather months in advance. The core flows that drive the field are turbulent, and small changes in those flows can produce large shifts at the surface. Researchers can observe the current trend and project it forward, but the pole has changed direction and speed before without warning. The acceleration that started in the 1990s was not predicted by models available at the time, and the specific cause, the flux changes under the New Siberian Islands, only became clear in retrospect.3Journal of Geophysical Research: Solid Earth. Magnetic flux expulsion from the core as a possible cause of the unusually large acceleration of the north magnetic pole during the 1990s – Section: Abstract
The World Magnetic Model is designed to be accurate for a five-year window, and even that requires careful monitoring and occasional emergency updates. Longer-term forecasts are more like informed guesses. If the current trend continues, the pole will keep moving toward Siberia. But the current trend may not continue. The core does not owe us a straight line.
Satellite missions like Swarm have dramatically improved the data available for building these models, giving scientists a near-continuous global view of the field rather than relying on scattered ground observatories.5Earth, Planets and Space. Geomagnetic Virtual Observatories: monitoring geomagnetic secular variation with the Swarm satellites That better data has shortened the lag between a change in the core and our awareness of it at the surface. But better observation is not the same as better prediction. The geodynamo remains one of the most complex physical systems on the planet, and humility about our forecasting ability is warranted.
What a Wandering Pole Does Not Mean
A few common misconceptions are worth clearing up. The north magnetic pole’s movement toward Siberia does not mean the field is about to flip. Pole drift and full reversals are related in the sense that both reflect changes in the core, but the current drift rate, while fast, is well within the range of normal secular variation. Reversals involve a collapse of the dipole field to a fraction of its usual strength over thousands of years, and there is no sign that this process is underway now.
Pole movement also does not mean your compass will suddenly point in a wildly different direction. In most of the world, the change in declination from year to year is a fraction of a degree, barely noticeable for everyday purposes. The effects are concentrated near the poles, where even moderate changes in the field geometry can swing compass readings more noticeably. If you live in the mid-latitudes, the practical impact on any compass-based activity is small and easily corrected with updated declination values.
Finally, the speed of the magnetic pole is not accelerating indefinitely. The pace of drift varies, and there are periods of faster and slower movement. The burst of speed that began in the 1990s drew attention precisely because it was unusual. Whether it represents a new normal or a temporary surge that will subside is an open question, one that the satellites overhead are watching closely.