Palaeomagnetism

At http://palaeomagnetism.geologist-1011.net/ … there is an interesting debate on magnetic reversals in Earth history. He concludes by saying the causes of magnetic reversals remian unclear and suggests it is as a result of an external magnetic force or flux. 'This raises the question of whether magnetic fluxes thousands of times higher than the maximum flux of the earth's magnetic field may alter the orientation of the earth's internal dynamo …' and 'I think it is possible that magnetic or solar storms may occasionally play an active role destabilising the earth's internal dynamo with respect to mass rotation …'.