Lehmann Discontinuity
The seismic boundary at a depth of ~5,150 km marking the transition between Earth's liquid outer core and solid inner core.
Governing formula
Depth z ≈ 5150 km (Outer Core - Inner Core Boundary)
SI unit
km (Boundary Depth)
In depth
Discovered by Danish seismologist Inge Lehmann in 1936 by analyzing weak P-wave reflections arriving in the core shadow zone.
Examples in the real world
P-wave reflection off the Lehmann discontinuity providing proof of a solid inner core.