[EmmaHildyard (OP)]

Chuck has asked a question on our facebook page...

I understand that the Earth's polarity has switched polarity, changing from north to south and south to north, frequently. This is recorded in the geologic record. Do we know why? What would happen to life on Earth if it happened tomorrow?

Can you help? Join the conversation here or on our facebook page...

[alancalverd]

Apart from upsetting pigeon and human navigation, nothing.

[pensador]

Chuck has asked a question on our facebook page...

I understand that the Earth's polarity has switched polarity, changing from north to south and south to north, frequently. This is recorded in the geologic record. Do we know why? What would happen to life on Earth if it happened tomorrow?

Can you help? Join the conversation here or on our facebook page...

The earths magnetic field flips approx every 50 000 250 000 years according to the geological record. The magnetic field of the earth protects the planet from solar radiation, and solar flares. If the field weakens and changes its orientation slowly it could leave the planet a little exposed to solar radiation. https://en.wikipedia.org/wiki/North_Magnetic_Pole

Solar flares also cause problems in electricity lines. A solar flare at the end of the Vietnam war 1973ish exploded lots of sea mines placed by the USA. Good job their nuclear war heads weren't affected It might have caused global cooling. https://www.scientificamerican.com/article/a-solar-storm-detonated-u-s-navy-mines-during-the-vietnam-war/

The mechanism behind the earths poles changing is not fully understood.

The sun has a 11 year sun spot cycle whereby it produces lots of solar flares. Fact

Edit The earths magnetic field was twice as strong in Roman times, http://www.geomag.bgs.ac.uk/education/reversals.html#4

[evan_au]

It is estimated that there have been 183 reversals in the past 83 million years.

This is about 2 every million years, but with a very wide range of variation.
- The last complete reversal was about 800,000 years ago.
- The current magnetic weakening suggests we may be heading for a (perhaps partial) reversal in a few thousand years.

See: https://en.wikipedia.org/wiki/Geomagnetic_reversal#Effects_on_biosphere

[pensador]

Perhaps more than pigeons will be affected, by the next reversal.

https://www.space.com/lava-flows-earth-magnetic-field-reversal.html?utm_source=sdc-newsletter&utm_medium=email&utm_campaign=20190808-sdc

https://advances.sciencemag.org/content/5/8/eaaw4621

Since the field is currently weakening and shifting does that make the planet more vulnerable to solar flares.

If the North pole shifted to above london say on its way south, would the aurora appear there. How would it affect power distribution, in the event of a solar flare.