Gutenberg Discontinuity
The major geophysical boundary located at a depth of ~2,890 km marking the sharp transition between Earth's solid mantle and liquid outer core.
Governing formula
Depth z ≈ 2890 km (Core-Mantle Boundary D'' Layer)
SI unit
km (Boundary Depth)
In depth
Discovered by Beno Gutenberg in 1914. Features an abrupt drop in P-wave velocity and complete disappearance of S-waves due to transitioning from solid mantle silicates to liquid iron outer core.
Examples in the real world
The D'' seismic boundary layer at the Gutenberg discontinuity hosting thermal mantle plumes.