Magnetic field reversals
The Earth’s magnetic field is aligned roughly along the spin axis and has an approximate dipole shape, similar to that of a bar magnet, with north and south magnetic poles. This is the normal state of affairs, but occasionally the magnetic field switches polarity, the north and south magnetic poles reverse, and the field settles down in the opposite state. The process goes by several names – “magnetic field reversal” and “polarity transition” are the most common.
Reversals have been documented as far back as 330 million years. During that time more than 400 reversals have taken place, one roughly every 700,000 years on average. However, the time between reversals is not constant, varying from less than 100,000 years, to tens of millions of years. In recent geological times reversals have been occurring on average once every 200,000 years, but the last reversal occurred 780,000 years ago. At that time the magnetic field underwent a transition from a “reversed” state to its present “normal state”.
Excuse me if this is a stupid question but what would it mean for humans, civilization in general if the poles were to reverse?