[MarianaM (OP)]

Ray is wondering...

The Earth has apparently reversed its polarity fairly regularly and is perhaps overdue for the next instance.
Is anything known about how this will happen and the effects? Will it be quick, or slow? Will the Earth's magnetic field be reduced for a period of time leaving us open to solar radiation and perhaps other effects? How will it affect our reliance on technology?

What do you think?

[Hayseed]

There is very good evidence that this planet is saturated with liquid hot water.  This is a solvent and there is a good chance that there could be charge and ion shell regions in the interior.   Like there are charge and ion shell regions in the exterior area.

The water would make a good high speed transport for a change.....or to respond to an external affect.   Induction.

And there is a possibility that the past reversals are only apparent.  And mistaken.

[evan_au]

The Sun reverses its magnetic field every 11 years or so.

The Earth is filled with molten rock and iron (hot water only occurring where the hot rock is close to the surface of teh land, or the bottom of the sea).

This hot rock and hot iron moves much more slowly than the hot plasma of the Sun, so reversals occur much less frequently on Earth.

This process is very hard to model in computers, but it has been reproduced in laboratory tests using liquid sodium.

The consensus seems to be that it takes thousands of years to flip Earth's "dipole" (North/South) magnetic field, but during this period, the Earth might be partially protected by a "quadrupole" magnetic field, which doesn't extend so far into space, and which has zero strength at some points on the Earth's surface.
See: https://en.wikipedia.org/wiki/Geomagnetic_reversal#Character_of_transitions

[Hayseed]

Quadrupoles(at lower lats) should give us some interesting light shows.

Might play hell for radio.   Skip patterns might change.

Confused Wildlife?

It's like Y2K all over again.  Maybe it's not climate change we need to be worried about.

Our shield falls and we all die when Sol burps.

[syhprum]

I think little communication takes place today via HF radio bouncing of the ionosphere most is carried by cable or satellite.
Power grids are organised as delta circuits so that ground induced currents are not relevant, the power supply to the repeaters in cables runs to several thousand volts so they are little affected by the few hundred induced by solar events.   

[alancalverd]

Baffling for pigeons and other species (cetaceae?) that navigate magnetically, including most light aircraft and yachts. Expect collapse of a few food chains, and piles of mechanical debris. 

[MeganM]

Thanks for the ideas everyone. We answered this question on our latest show by talking to a geologist. You can listen here https://www.thenakedscientists.com/podcasts/question-week/will-poles-switching-cause-problems [nofollow]