Can the Earth lose its North Pole? (The)

Jean-Pierre Valet who is a paleomagnetician at the Institut de Physique du Globe de Paris (Paris geophysical institute - IPGP) explains how the magnetic field surrounding the Earth protects us. Where did it come from? How does it change? If compasses had existed 800,000 years ago, their needles would have pointed... south! Since the Earth's magnetic field has existed, it has reversed many times.
How did scientists discover our planet's stunning magnetic past? Should we expect the Earth to lose its North Pole again?

Ce film fait partie d'une série de 22 films intitulée "Les dessous de la planète".