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North Magnetic Pole Racing Toward Siberia

Posted by kdawson on from the slowly-swinging-needles dept.

RogerRoast sends along a backgrounder from Scientific American on the best current theory as to why the north magnetic pole drifts. "The NMP, also known as the dip pole, is the point on Earth where the planet's magnetic field points straight down into the ground. Scottish explorer James Clark Ross first located the NMP in 1831 on the Boothia Peninsula in what is now northern Canada... [T]he NMP drifts from year to year as geophysical processes within Earth change. For more than 150 years after Ross's measurement its movement was gradual, generally less than 15 kilometers per year. But then, in the 1990s, it picked up speed, ... bolting north–northwest into the Arctic Ocean at more than 55 kilometers per year. If it keeps going it could pass the geographic north pole in a decade or so and carry on toward Siberia."

4 of 187 comments (clear)

  1. Eeep! by jd · · Score: 5, Funny

    Will Putin's ambitions stop at nothing?

    (Besides, a fast-moving magnetic pole screws up the UK's Ordinance Survey maps, which are magnetic north aligned.)

    --
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    1. Re:Eeep! by jc79 · · Score: 5, Informative

      Parent is wrong. Ordnance Survey maps are NOT magnetic north aligned. They are aligned to OS Grid North, which is fixed wrt the UK (but not congruent with True North). Each printed map sheet has a diagram indicating the deviation from grid north of magnetic north at the centre of the sheet at a given epoch. When taking a bearing with a protractor compass, it is necessary to account for the magnetic deviation before following that bearing (in Scotland, magnetic north is currently 2 deg west of grid north).

    2. Re:Eeep! by icebike · · Score: 5, Insightful

      The funny thing is.... No one knows if this speed-up is a natural cycle, or if there's really something out of whack with the core.

      There being no artificial means of altering the magnetic field of the entire planet, you can rest assured that the speed up is a natural occurrence. /smirk

      As for it being part of a cycle, magnetic pole wandering, and indeed complete reversals, while documented in geology, follow no easily discernible pattern over time, with long periods of stability followed by many reversals over a short period.

      There are some claim the pattern is a Lévy distribution, but this has yet to be proven, and that fact by itself provides no predictive capabilities.

      There is a pretty good wiki article on this. The article includes a time-chart showing reversals of the magnetic field. There are very long periods of stability, as well as periods of frequent short reversals.

      Magnetic Pole reversals happen over a period of time of tens of thousands of years, and a reversal is proceeded by a diminishing of field strength, not necessarily by pole wandering. The current rate of field strength weakening suggests a reversal sometime in the years 3000-4000.

      So the speed up of the NMP's movement is not significant in estimating a reversal, and a reversal does not signify anything out of "whack" with the core of the earth.

      It is a perfectly natural thing that has occurred many many many times. And yes, mankind has lived thru reversals entirely unaware.

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  2. World stability by snsh · · Score: 5, Funny

    This is good news. Everyone knows that you regain stability by moving all your poles into the right hand plane.