Core-Mantle Angular-Momentum Exchange (Decadal LOD)
mechanism
The Earth's core and its outer shell do trade spin — but so little that the core can't suddenly slip loose and wreak havoc.
Who they are
The exchange of rotational momentum across the boundary between Earth's core and mantle, seen in tiny decade-scale changes in day length.
What they do
The engine cites this as proof the core and mantle are mechanically locked together, not free to slide.
How it works
Day-length variations show momentum genuinely crosses that boundary, but the total change in the core's spin is under one part in 100,000 — meaning the coupling acts as a strong brake, not a slip.
Why it matters
It's another peer-reviewed geophysics fact the engine uses to rule out a runaway-core disaster scenario.
The engine's record — word for word
Decadal length-of-day variations show angular momentum IS exchanged across the core-mantle boundary, but the total relative core angular-momentum change is <1e-5. The coupling is a powerful mechanical brake against runaway differential rotation — not a slip mechanism. [TIER GEOPHYSICS-PEER-REVIEW; Apex (a)] [Report #103 (ECDO)]
Follow the trail
Walk this on the live map →