T The Earth's magnetic field has always been in motion, thanks to the changing patterns of molten metals in the outer core of the planet. But a new report suggests that this natural variability has taken on surprising dimensions since 2015. New geological evidence shows that the Earth's magnetic field is changing much more frequently than usual. It is not great news for crucial global networks that depend on its stability, such as navigation tools and satellite GPS, as well as natural phenomena such as animal migration and even the protection we receive from solar winds.
The report, published in Nature on Wednesday, showed that the Earth's magnetic field is shifting so rapidly and unpredictably that it is making the models on which our lives depend obsolete at a faster pace than never. Scientists are struggling to keep up.
Normally, scientists with the US National Oceanic and Atmospheric Administration and the British Geological Survey meet every five years to produce a model of the Earth's magnetic field called the World Magnetic Model. The WMM, which maps the current status of the exchange field, helps technologists, researchers and navigators around the world to maintain a shared map of the Earth's magnetic field.
Since the WMM is updated only every five years, scientists build a range of variability to account for the subtle changes that will inevitably occur before the next update.
But so much has changed since the WMM 201
Shortly after the publication of the WMM 2015, several factors quickly contributed to making it less useful. Already in 2016, scientists pointed out that the magnetic field was changing faster than expected when the ESA swarm satellites found that the region above South America was changing particularly rapidly. Then, in 2018, a phenomenon in the field between South America and Africa, called the South Atlantic Anomaly, weakened so much that it actually interrupted the satellites as they crossed the region.
The news of these two events raised concerns about the Earth that was about to undergo an inversion of total magnetic pole, in which the north and south poles completely exchange positions. An event like this would have devastated the satellites electric lines, ocean currents and animal migrations. And while the concerns that the Earth's magnetic field is reversed in the near future are probably unrealistic, geophysicists have noticed that the Earth is late for a reversal, historically speaking.
Regardless, the drastic changes that actually did far exceeded the level of variability that scientists predicted when they made the WMM 2015, making it a more urgent solution than ever.
As originally reported by Witze, this mid-term update was to be released on January 15, but not long after its publication of the article, it was updated to note that the closure of the US government had rejected at least until January 30
Once released, international shipping companies, GPS-based app programmers and anyone else for whom important magnetic maps are important will have to rely on interim upgrades. Fortunately, reports Witze, researchers working on the short-term map have included data from the years starting in 2015, which include the main anomalies that have knocked out the WMM 2015 in the first place. The update should remain valid until 2020, subject to any unforeseen irregularities. But as history has shown, irregularities seem to have become the rule, rather than the exception.