According to Nature, Earth’s north magnetic pole is moving so quickly that the World Magnetic Model (WMM) needed to be updated only four years after its latest update.  Even though the 2015 update to the model was expected to remain valid until 2020, it’s close to exceeding the acceptable limit for navigational errors. so, updates were made and released in February 2019. Periodically, the north and south poles move so much that they trade locations, which is known as a magnetic field flip.This phenomenon most likely should not occur for thousands of years, however. But, the fact that WMM needed to be updated so quickly has us questioning what is it that causes the poles to shift, and what this means for Earth’s magnetic field. Below, we outline what all plays into the changes. Where’s Earth’s Magnetic Field? First measured in 1831 by James Clark Ross, the magnetic pole was found in the Canadian Arctic moving toward Siberia, entering into the Arctic Ocean. Last year, it crossed the International Date Line into the Eastern Hemisphere. There was also a geomagnetic pulse beneath South America in 2016 (soon after the last update to the WMM model was created) that shifted the magnetic field. The Potential Flipping of Earth’s Magnetic Field Aside from the shifting pole, it also appears that the core field is weakening by approximately seven percent every 100 years. This field represents about 75 percent of the intensity of Earth’s magnetic field at the planet’s surface, with the other 25 percent of Earth’s magnetic field being generated from a second field. As the core field loses intensity, this second field gains more influence over the planet’s global magnetism, allowing a flip to happen.    What Happens When Earth’s Magnetic Field Flips? A geomagnetic reversal—the flipping of the Earth’s magnetic field—is a long process, and it wouldn’t happen overnight. The flip would, however, leave us more susceptible to cosmic and solar radiation --  the last time this occurred, Earth’s magnetic field weakened beforehand.  In reality, one of the only things we would notice after the switch happens is that our compasses would read differently. North will then point toward Antarctica, while South will point toward Canada. If the magnetic field considerably weakens, however, Earth will be less protected from higher levels of radiation. Although we don’t have reason to worry about Earth’s magnetic field flipping anytime soon, it’s useful to understand how the poles are shifting and what that could mean for the future of our planet. To learn more about the history of Earth’s magnetic field and other theories about pole reversal, consult our Magnets in the News blog or subscribe to our newsletter for magnetic updates and discoveries like this to be sent to your inbox each month.