https://thenextweb.com/syndication/2018/07/29/the-earths-magnetic-field-is-reversing-more-than-ever-heres-why/

Andrew Biggin, University of Liverpool and Mark Hounslow, Lancaster University

Underneath our feet, deep down in the Earth, liquid iron is producing the magnetic field that we all take for granted. But every now and then that magnetic field reverses or flips its polarity. What was once magnetic north becomes south – and vice versa. When these reversals take place – and why they do so – has been an enduring mystery.