Merely what the title states. My knowledge of geography/geology/*logy is limited to high-school, and some snippets, and snatches of conversation.

As I understand Earth's magnetic field is attributed to the bi-layered nature of it's core. Proto-Earth probably did not have a magnetic field. Apparently much later Earth's core cooled enough to separate into two layers - causing the field to appear

How long did it take for Earth's magnetic field to first appear? As a corollary, did water appear first on Earth, OR did the magnetic field appear first?


1 Answer 1


The age of the Earth's magnetic field could be as old as the existence of the physical conditions capable of generating a magnetic field. Because we believe the geomagnetic field originates from the liquid outer core, your question could be restated as: When did the Earth form a liquid core?

How the Earth's core formed is still not well understood and the area of research is referred to as planetary differentiation.


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