so there is a cycle? based on what, do you think?
when is earth next due? seems I’ve read the magnetism is now weakening
There’s a definite cycle but you would have to ask a geologist for theories on what causes it. I believe the name of the ship that discovered the magnetic banding of the sea floor was called the Glomar Explorer.
As far as magnetic field weakening is concerned, it makes sense that as a molten core cooled, the magnetic field it produces would weaken.