What happens when the Earths field reverses?
It appears that during a reversal of the magnetic field, the dipole component of the field (the dipole is analagous to a bar magnet) slowly decays and grows in the opposite direction. The time that it takes to complete a reversal is also the subject of ongoing debate, but time scales on the order of 10’s to a thousand years are commonly cited. There doesn’t seem to be any strong correlation between field reversals and extinctions. This may mean that when the main dipole field reverses, animal and plant life are protected by the higher order components of the Earth’s magnetic field.
