Planet’s erratic magnetic field forces emergency update to global navigation system
Unprecedented changes required to ensure accuracy of system that guides everything from aircraft to smartphones By Josh Gabbatiss Science Correspondent https://www.independent.co.uk/news/science/magnetic-north-pole-moving-arctic-siberia-canada-earth-navigation-ships-a8724426.html Earth’s magnetic north pole is veering towards Siberia at an incredibly fast rate, and experts are not sure why. The erratic movement has forced the scientists tasked with monitoring the planet’s magnetic field to update their system that underlies global navigation, from Google Maps to shipping. As liquid iron swirls around in the Earth’s core, the magnetic field – and therefore the poles – shift around gradually and often unpredictably. Scientists must periodically update the World Magnetic Model to map this process, and the most recent version – produced in 2015 – was intended to last until 2020. However, the magnetic field has been changing so quickly and erratically that while conducting a routine check in early 2018, British and US researchers realised drastic steps were needed. The shift they observed was so large it was on the verge of exceeding the acceptable limit for navigation errors. To account for this, scientists at the British Geological Survey and the US National Oceanic and Atmospheric Administration (NOAA) are issuing an unprecedented emergency update to the model. They have fed in the latest data, including an unexpected geomagnetic pulse that took place beneath South America in 2016, to ensure the system is more accurate. The movement of the north pole, which has been accelerating over the past 40 years, has further exacerbated the shifting magnetic field and made the new model all the more necessary. Its release was meant to be imminent, but the ongoing US government shutdown means it has now been delayed until the end of January. The changes are essential as the system is used by aircraft, ships and even smartphones, which make use of the Earth’s magnetic field to establish which direction someone is facing. The shift is felt more keenly in the Arctic around the north pole, meaning any vessels in the region would be hardest hit by an inaccurate model. “The fact that the pole is going fast makes this region more prone to large errors,” NOAA geomagnetist Dr Arnaud Chulliat told Nature. However, the scientists are still unclear about what exactly is behind the recent changes. Waves rising from the Earth’s core may be behind the kind of geomagnetic pulses that took place in 2016, and the shifting north pole may result from a high-speed jet of liquid iron underneath Canada. As they continue to investigate what is triggering the dramatic changes below our feet, the researchers hope their latest update will remain accurate until the next planned update in 2020. -- Cheers, Stephen _______________________________________________ Link mailing list [email protected] http://mailman.anu.edu.au/mailman/listinfo/link
