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Old August 25th 18, 12:50 AM posted to sci.astro.research
Bruce Scott
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Default Actual linkage between tectonic-mantle motions and lunar

On 2018-08-20, Phillip Helbig (undress to reply)
wrote:
In article ,
writes:

Earth core heating can be stated as an effect of Sun/Earth/Moon
gravity tidal effects.


That certainly plays a role. However, the Earth is heated by
radioactivity to a significant extent as well.


The text by W Hubbard on Planetary Interiors notes that the Earth has
an unusually large dissipation coefficient for tidal dissipation and
suggests a lot of it is in the surface or near surface layers. Tidal
motion of the oceans (main sloshing period about 40 hours, compared to
the 24 hr rotation... IIRC originally noted by Laplace) seems to have
a big effect. The discussion suggested that not a lot of the tidal
effects in the Earth have to do with the core.

Quesiton about the radioactive heating: is it more Potassium 40 in the
deep core anyway (I thought the heavy U or Th stuff was closer to the
surface, maybe outer mantle)?

--
ciao, Bruce