Seafloor Spreading
The tectonic process occurring at mid-ocean ridges where new oceanic crust is created by upwelling mantle magma and moves laterally away.
Governing formula
Spreading Rate v = d / t ~ 2–16 cm/year
SI unit
cm/year (Spreading Rate)
In depth
Proposed by Harry Hess in 1960. As tectonic plates diverge, asthenospheric mantle upwells, melts via decompression, and solidifies into new basaltic oceanic crust, carrying paleomagnetic stripe records.
Examples in the real world
The Mid-Atlantic Ridge producing new oceanic crust and widening the Atlantic Ocean by ~2.5 cm/year.