Slashdot Mirror
Earth's Magnetic Field Is Acting Up and Geologists Don't Know Why (nature.com)
schwit1 quotes Nature:
Something strange is going on at the top of the world. Earth's north magnetic pole has been skittering away from Canada and towards Siberia, driven by liquid iron sloshing within the planet's core. The magnetic pole is moving so quickly that it has forced the world's geomagnetism experts into a rare move. [T]hey are set to update the World Magnetic Model, which describes the planet's magnetic field and underlies all modern navigation, from the systems that steer ships at sea to Google Maps on smartphones. The most recent version of the model came out in 2015 and was supposed to last until 2020 -- but the magnetic field is changing so rapidly that researchers have to fix the model now.
"The error is increasing all the time," says Arnaud Chulliat, a geomagnetist at the University of Colorado Boulder and the National Oceanic and Atmospheric Administration's (NOAA's) National Centers for Environmental Information.... By early 2018, the World Magnetic Model was in trouble. Researchers from NOAA and the British Geological Survey in Edinburgh had been doing their annual check of how well the model was capturing all the variations in Earth's magnetic field. They realized that it was so inaccurate that it was about to exceed the acceptable limit for navigational errors.
Nature's article was updated on January 9th to inform readers that the release of the corrected World Magnetic Model, which should restore accuracy through the end of 2019, has now been postponed from January 15th to January 30th -- "due to the ongoing US government shutdown."
"The error is increasing all the time," says Arnaud Chulliat, a geomagnetist at the University of Colorado Boulder and the National Oceanic and Atmospheric Administration's (NOAA's) National Centers for Environmental Information.... By early 2018, the World Magnetic Model was in trouble. Researchers from NOAA and the British Geological Survey in Edinburgh had been doing their annual check of how well the model was capturing all the variations in Earth's magnetic field. They realized that it was so inaccurate that it was about to exceed the acceptable limit for navigational errors.
Nature's article was updated on January 9th to inform readers that the release of the corrected World Magnetic Model, which should restore accuracy through the end of 2019, has now been postponed from January 15th to January 30th -- "due to the ongoing US government shutdown."
what matters is how everyone else measures...
For example, in Sydney there is a 200 metres (700 feet) difference between GPS coordinates configured in GDA (based on global standard WGS 84) and AGD (used for most local maps), which is an unacceptably large error for some applications, such as surveying or site location for scuba diving
see : https://www.icsm.gov.au/datum/what-gda2020
Airplane pilots still use magnetic headings to identify runways which is gazillion times simpler than using GPS (doesn't even require power). Runways are numbered according to their orientation relative to the horizontal magnetic field (their declination). The wandering of the North pole is however inconvenient as these runway numbers must be changed accordingly every now and then.
Thinking about it, maybe they skimped on compass and put super secret GPS inside instead?
That's how the CDMA providers handled E911 requirements at first... even phones where you had no access to the GPS had a GPS receiver solely for E911 compliance. GSM got a waiver for a while and then did it with DTOA instead. But maybe they're just averaging out readings while removing anomalous ones, and doing constant live compass calibration instead of trying to account for declination with mathematics. There's something to be said for that approach, because you don't have to update declination.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
The Earth's magnetic field deflects charged particles from the sun, sending them to the polar regions where they become the aurora when they hit the atmosphere. This creates a low-radiation bubble up to a certain altitude above the Earth. GPS satellites orbit in between the two major belts where radiation is deflected.
A pole flip may be associated with a weakening magnetic field for a short time during the flip. In which case those charged particles will not be deflected towards the poles. They will strike all the satellites that were formerly protected, like GPS satellites. Those satellites have some radiation hardening to survive the occasional solar flare, but probably would not survive something this intense for too long.