The Earth’s geomagnetic field, which governs everything from the size of animals to the efficacy of electrical grids, may be in for a big change.
Scientists from the Russian Academy of Sciences say the earth’s magnetic poles are gradually drifting towards the Equator, with the earth’s field intensity falling slowly but steadily from 2.5 gauss about 65 million years ago to less than .5 gauss today.
A gauss is a measurement used to quantify magnetic strength, and equals 0.00001 tesla, but this information is useless to all but scientists. It won’t even help to know that a small iron magnet exerts 100 gauss, because you have to factor the size of the object into the equation. All you really need to know is that most scientists agree about pole shift, with some predicting a shift in the near future. However, when asked to define ‘near’, the estimates range from immediate to 2,000 years.
It won’t be the first time it has happened. In fact, earth’s polarity has shifted a number of times in the past, usually in 250,000-year intervals (based on the study of lava flows and old ship’s records). One such shift, called the Brunhes-Matuyama reversal, is estimated to have occurred about 780,000 years ago, or double the time between the two pole shifts prior to that. This unexpectedly long interval is, in fact, what has scientists concerned about a coming pole shift.
In 2001, an international polar expedition discovered that the earth’s North magnetic pole has shifted about 186 miles since 1994. This drift continues today, moving about 25 miles a year from the Canadian Arctic toward the Severnaya Zemkya islands north of Russia in the Arctic Ocean, leading some scientists to predict that the North Pole may eventually end up in the South Atlantic. This speculation is supported by an anomaly in that area with a surprisingly high magnetic field intensity of about 60 percent. Although how a shift to the east predicts a subsequent movement south is beyond me.
The movement and shift is further supported by the fact that, in the last two decades, Earth’s field intensity (measured in gauss and mentioned above) has shrunk by almost 2 percent, with a decrease in the South Atlantic nearer 10 percent.
This decline in field intensity is one of the factors leading scientists to predict a pole reversal. What they can’t even guess at is how long before it happens, how the transition occurs, or what happens to living creatures at the time.
If the magnetic field were to drop rapidly to zero, and it might, electronic devices would fail, orbiting satellites would be useless, power grids would black out, and our electronically-sensored and controlled vehicles would come to a standstill. Airplanes wouldn’t fall from the sky, but pilots would need the skill to bring them in without equipment or ground control communications. Radiation would be the biggest concern. Even now, with the field at .5 gauss, the EU has moved to classify airplane pilots and flight crew as hazardous occupations, and frequent fliers are warned of the dangers they face.
Lacking the protection of the Van Allen Radiation Belt (the name for earth’s protective layer generated by its magnetic field), earth life forms would feel the effects as the atmosphere leaked into space. This would also let in deadly radiation. The results would be altitude sickness, even at sea level, immune system failures even in the healthiest, and radiation-induced cancers among most of the population. Birds, bats, bees, whales and even cows, who operate with an ‘internal compass’, would lose their way back to their hives, nests and homes, and likely die. Ultimately, cosmic radiation would kill all surface dwellers, and only those living underground or in reinforced shelters would be spared.
Countering this apocalypic vision, other scientists argue that the magnetic field could never fall to zero, but at worst become disordered, wandering around and giving the Earth various and occasionally duplicate North and South Poles until it stabilized.
This disorder theory is supported by geologic evidence showing that past reversals did not begin with total field collapse, but rather extreme fluctuations which eventually resolved themselves. In that case, machines might not be useful, but we humans would find a way to survive and take our livestock and pets with us.
Since we still don’t know for certain how earth’s magnetic field is generated, either scenario is possible. We can’t even use our own sun (which reverses its magnetic field like clockwork every 11 years) as a model, because earth’s magnetic field may operate on entirely different, and largely unsuspected, principles.
However the scenario plays out – if it does play out – scientists agree from studying lava flows that we will have 4,500 years to adapt, because that’s how long polarity takes to re-establish itself. In those 4,500 years, humankind and all the creatures we have come to recognize may evolve in unexpected ways due to increased radiation. In fact, changing poles may be the earth’s way of pushing us all to evolve, since we rarely undertake it on our own.