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."

18 of 192 comments (clear)

  1. Declination is not news by Anonymous Coward · · Score: 5, Informative

    Declination needs to be changed every year by serious navigators. More often near the poles. This has been true since before any slashdot reader was born.

    The magnetic shift is increasing in complexity and rate of change. This has also been known for a very long time.

    We are overdue for a pole shift given our current understanding of the magnetosphere. We might be lucky enough to witness multiple north and south poles, followed by a rapid reversal where every magnetic compass in the world will point the wrong way.

    1. Re:Declination is not news by abies · · Score: 3, Informative

      I guess serious navigators have access to a super secret GPS system which can tell them which way is north?

      You need to move few meters and GPS will tell you where north is. Take mobile phone navigation for example - my phone has horrible internal compass and often shows direction off by 90 degrees or so. But it is enough to start driving and suddenly it corrects itself. Thinking about it, maybe they skimped on compass and put super secret GPS inside instead?

    2. Re:Declination is not news by Z00L00K · · Score: 4, Funny

      The inside of the Earth is liquid and not homogeneous so things changes quite a bit over time.

      I wonder if a polarity change will coincide with eruption of Yellowstone. And I worry more about an eruption than a polarity change.

      --
      If builders built buildings the way programmers wrote programs, then the first woodpecker would destroy civilization.
    3. Re:Declination is not news by Z00L00K · · Score: 4, Informative

      If you want to get the true north - get a gyro compass.

      --
      If builders built buildings the way programmers wrote programs, then the first woodpecker would destroy civilization.
    4. Re:Declination is not news by repepo · · Score: 4, Interesting

      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.

    5. Re:Declination is not news by reboot246 · · Score: 5, Insightful

      Really serious navigators know how to use every system of navigation. If your GPS receiver quits, you're the one who is lost. Don't rely solely on technology. You can find yourself in trouble pretty damned fast.

    6. Re:Declination is not news by Ol+Olsoc · · Score: 4, Funny

      They want to make it sound dramatic so it is big news. Perhaps soon they will have a way to blame the magnetic pole shift on carbon emissions.

      Or Mexican rapists.

      --
      The shepherds did so well protecting the flock that the sheep no longer believed that wolves existed.
    7. Re:Declination is not news by drinkypoo · · Score: 3, Interesting

      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.'"
    8. Re:Declination is not news by mysticgoat · · Score: 3, Funny

      Fully agree.

      And thank you for introducing to me the term "millennial statement". I've been hearing an increased number of them lately, and it's good to have a label for them.

      Millennial thinking is two generations removed from being able to calculate a square root when there is no button for it within reach.

    9. Re:Declination is not news by iggymanz · · Score: 4, Informative

      You might have read alarmist articles on the matter.

      The serious science is this:

      reversals are rapid

      the magnetic field does not disappear during reversals though there may be multiple poles

      no extinctions correlate with them

      the solar wind interacting with the upper atmosphere would protect us from cosmic rays

      so the "fun" would be technology / navigational system issues, no anything directly dire to life

      https://arxiv.org/abs/astro-ph...

    10. Re: Declination is not news by angel'o'sphere · · Score: 3, Informative

      Yellowstone is a supervolcano.
      Chances are that half of the US are gone and the earth goes into a "nuclear winter" when it erupts.

      --
      Cost free eBook I read (by iBook/Kobo/Amazon/ObookO/Gutenberg etc.): "The Green Odyssey" by Philip Jose Farmer.
    11. Re:Declination is not news by Solandri · · Score: 4, Interesting

      Serious navigators use GPS, which is a gazillion times more accurate than figuring out where you are with a compass and sextant.

      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.

    12. Re:Declination is not news by viperidaenz · · Score: 3, Insightful

      It's not like we'll be carrying around calculators in our pockets when we grow up!

      That's what my math teacher used to say in the 90's.

    13. Re:Declination is not news by RockDoctor · · Score: 3, Informative
      reversals are rapid Define "rapid." There's at least one sill (intrusion parallel to country rock lamination) which solidified during a reversal. The event was too rapid to "see" through direct radiometric dating, but by measuring the melting temperature of the rock (the texture indicates that it was emplaced fairly fluid), the Curie temperature and with how well the surrounding rocks conduct heat, the cooling time of the sill is estimated as taking several centuries. And the orientation of the magnetic field changed by about 150 degrees during those centuries.

      But yeah, "rapid" for certain meanings of "rapid".

      the magnetic field does not disappear during reversals though there may be multiple poles That is how the models go - and it is not incompatible with the observations noted above. They're well supported models, but not observations.

      no extinctions correlate with them

      No more than would be expected by chance. No fewer, either.

      so the "fun" would be technology / navigational system issues, no anything directly dire to life

      Yep, I'd look forward to living through one, particularly since that would imply a lifetime of several centuries.

      --
      Birds are not dinosaur descendants;birds are dinosaurs, for all useful meanings of "birds", "are" and "dinosaurs"
  2. Re:Time and Tide by arglebargle_xiv · · Score: 4, Funny

    Earth's north magnetic pole has been skittering away from Canada and towards Siberia,

    Russian interference again, no doubt.

  3. Geocentric Datum and maps... by johnjones · · Score: 5, Interesting

    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

  4. Re:Global warming by Ol+Olsoc · · Score: 3, Funny

    Cow farts

    One of the mods gets a plus 5 funny for modding cow farts as flamebait!

    --
    The shepherds did so well protecting the flock that the sheep no longer believed that wolves existed.
  5. Re:Only because Gov't Shutdown by jittles · · Score: 4, Funny

    Why does it have to be the U.S. government's job to produce a "World Magnetic Model"? If boats might collide, would it not be better for them to rely on more than one source for this information? This article was politically motivated. When I first saw this article appear, the page was also littered with climate change propaganda.

    Why does Paris have to be responsible for defining the kilogram? NOAA puts out a model for US government and commercial use. The information is so useful that other countries have adopted it for their government and commercial use, also. Now the model is not being published because a big baby isn't getting money for a wall that he said would come from Mexico to begin with. Did you know that NOAA is also responsible for 99.999999% of the weather forecast data that is used by private business? And that the CDC helps manage food and water borne illness through the globe and not just in the US? All of those activities are of use to the world and publishing this information helps to improve business and commerce for US companies.

    Could someone else publish this model? I am certain it is possible. But sometimes the prestige involved in having that come from your specific country is useful. I think it would be worthwhile for the US to continue to be the source of such useful scientific and commercial knowledge. Are you saying that we should let our position in this slide because of a border wall that nobody really needs? I mean, you are aware that over half of the illegal immigration that occurs these days is by airplane and people overstaying visas, right? My understanding is that the wall will not be high enough to prevent immigrants from coming over by air.