Earth’s magnetic pole reversal happens all the [geologic] time

Scientists understand that Earth’s magnetic field has flipped its polarity many times over the millennia. In other words, if you were alive about 800,000 years ago, and facing what we call north with a magnetic compass in your hand, the needle would point to ‘south.’ This is because a magnetic compass is calibrated based on Earth’s poles. The N-S markings of a compass would be 180 degrees wrong if the polarity of today’s magnetic field were reversed. Many doomsday theorists have tried to take this natural geological occurrence and suggest it could lead to Earth’s destruction. But would there be any dramatic effects? The answer, from the geologic and fossil records we have from hundreds of past magnetic polarity reversals, seems to be ‘no.’

Reversals are the rule, not the exception. Earth has settled in the last 20 million years into a pattern of a pole reversal about every 200,000 to 300,000 years, although it has been more than twice that long since the last reversal. A reversal happens over hundreds or thousands of years, and it is not exactly a clean back flip. Magnetic fields morph and push and pull at one another, with multiple poles emerging at odd latitudes throughout the process. Scientists estimate reversals have happened at least hundreds of times over the past three billion years…

Earth’s polarity is not a constant. Unlike a classic bar magnet, or the decorative magnets on your refrigerator, the matter governing Earth’s magnetic field moves around. Geophysicists are pretty sure that the reason Earth has a magnetic field is because its solid iron core is surrounded by a fluid ocean of hot, liquid metal…The flow of liquid iron in Earth’s core creates electric currents, which in turn create the magnetic field. So while parts of Earth’s outer core are too deep for scientists to measure directly, we can infer movement in the core by observing changes in the magnetic field. The magnetic north pole has been creeping northward – by more than 600 miles (1,100 km) – since the early 19th century, when explorers first located it precisely. It is moving faster now, actually, as scientists estimate the pole is migrating northward about 40 miles per year, as opposed to about 10 miles per year in the early 20th century.

Another doomsday hypothesis about a geomagnetic flip plays up fears about incoming solar activity. This suggestion mistakenly assumes that a pole reversal would momentarily leave Earth without the magnetic field that protects us from solar flares and coronal mass ejections from the sun. But, while Earth’s magnetic field can indeed weaken and strengthen over time, there is no indication that it has ever disappeared completely. A weaker field would certainly lead to a small increase in solar radiation on Earth – as well as a beautiful display of aurora at lower latitudes — but nothing deadly. Moreover, even with a weakened magnetic field, Earth’s thick atmosphere also offers protection against the sun’s incoming particles.

I couldn’t resist posting this. I know a Christian science teacher who’s stuck into the idea of incoming solar activity roasting us on the playing field of life. I’m not certain if he plans to purchase some kind of anti-radiation suit or just move underground for a couple hundred years.

7 thoughts on “Earth’s magnetic pole reversal happens all the [geologic] time

  1. Robert says:

    Yep, it’s happened about 8 times and 6 of them have co-incided with mass extinctions. When you consider that the bvan allen Belt is the only thing protecting us from anihilation from cosmic rays and that it is only maintained by the magnetic field of the earth, then you can probably see a problem.
    I think the charge of the solar wind could cause thes reversals if the net charge were to change then the induction of the earth could reverse the poles.Anyway, i can’t remember what happened way back then.

    Robert O. Becker wrote a very good book called The Body Electric and he mentions these reversals and more.

    • moss says:

      RTFA: “Scientists estimate reversals have happened at least hundreds of times over the past three billion years…”

      As an example: “The last time that Earth’s poles flipped in a major reversal was about 780,000 years ago, in what scientists call the Brunhes-Matuyama reversal. The fossil record shows no drastic changes in plant or animal life.”

      Reflect on paleontology – not prophecy, dude.

    • god says:

      RTFA means click the link and Read The Fracking Article. Start with NASA and move through basic geology and paleontology texts in university. Truck on over to the Max Planck Institue if need be – taking the time to utilize peer-reviewed jounals,

      Not the Alchemists Journal or what-if woolgathering whoopee publications. Science – dude – is what moves knowledge and civilization forward, not mystical theorizing. Temporal boundaries for any of these reversals are defined in thousands of years. Significant extinctions involve shorter boundaries. And of course a record of events happening at the same time or overlapping does not constitute cause-and-effect.

      You may be convinced of your idealist premises and that’s your right. That isn’t a challenge to the process and progress of scientific learning.

    • god says:

      As noted above, the NASA article references the hundreds of times such reversals have occurred. Your premise is several. That “fossil” record is a geologic record – the difference is significant in time and substance.

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