Mantle Convection
The slow, highly viscous thermal convection currents within Earth's solid silicate mantle transporting internal core heat toward the surface.
Governing formula
Ra = (ρ g α ΔT d³) / (κ η) (Rayleigh Number > Ra_critical)
SI unit
cm/year (Convection Motion Speed)
In depth
Driven by decay of radioactive isotopes (Uranium, Thorium, Potassium) and primordial heat of Earth formation. Hot, lower-density mantle rock slowly ascends at mid-ocean ridges, while cold, denser subducting oceanic lithosphere sinks back into the asthenosphere.
Examples in the real world
Mantle convection plumes driving global plate tectonics and forming hotspot volcanic chains like the Hawaiian Islands.