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Is this excursion into geophysics a distraction from the original radio topic?.... maybe; but all things of science are all connected- understand the subtle phenomenons and you gain insight into the bigger picture.
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Pole reversals are a fact of life. Though in terms of one occurring within a (our) human life time is extremely rare, their is current evidence that a reversal can occur in only a matter of years. In certain paleomagnetic samples taken from ancient lava flows **--- the alignment of magnetic deposits show realignments frozen in time that occurred over only a matter of years. It was previously thought to take 4-6 thousand years for this to occur- but there is this new evidence.
And based on past history, we are overdue.
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The signs are all there- the steady weakening of the magnet fields over the last hundred years, the last stable realignment three quarter's of a million years ago.
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But even with an 'overnight' flip, very few people will even be aware of what occurred. Planes won't fall out of the air, radios will still work, disruptions to the power grids are highly questionable, there maybe Northern Lights visible in Florida....you might want to buy a new compass...
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But in geophysical time I wouldn't worry about it anytime soon.
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Now Global Warming is something else.
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Love it- Embrace it !
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We are living in one of the rarer earthly epoch's- an Interglacial. The history of the Earth is one written ln ice.... we have been in this period of warmth far too long...and we are definitely due for another ice age. It was only a blink in the eye of God that major portions of North America were last cover'd in 2 mile! thick ice sheets--- and an interglacial warm period can begin to collapse in just a single lifetime.
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Your 40 metre dipoles on the shores of Lake Michigan aren't going to work worth a hoot under all that frozen stuff ...
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Lauri
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** Awhile others bask in the sun of the Pacific shores of Hawaiian Islands, geeks like me drive up to mountains geology field stations to see this stuff.
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