300 Foxes and a Donkey's Jawbone
Earth's magnetic field and dipole moment are used as evidence that hell isn't at the center of the Earth. They can also be used as evidence that hell IS at the center of the Earth. You choose what you believe.
Hell is the source of Earth's gravitational field, it's iron-rich so it produces its magnetic field, and its rotation causes its electric charge (dipole moment). This resolves gravitation with electromagnetism into a unified field theory.
The popular science (SciPop) rationalization for the liquid outer core is an ephemeral strand of wispy logic. It predates Stephen Hawking but it's an example of the Hawking Effect. All it has to do is sound plausible.