It depends on the rate of cooling of Earth 's core .
It is possible that during the Proterozoic , the magnetic field did not approximate a simple dipolar distribution , with north and south magnetic poles roughly aligning with the planet 's axis as they do today .
Depending on the rate of cooling of Earth 's core , it is possible that during the Proterozoic , the magnetic field did not approximate a simple dipolar distribution , with north and south magnetic poles roughly aligning with the planet 's axis as they do today .