The answer to How long until Earth's core solidifies? question cites an estimation that the Earth (as a planet, not the surface of it) has cooled down by about 250K since it was formed.

The question is, just by how much the Earth's effective/average diameter has decreased because of this cooling?

Also, considering that the Earth's crust has appeared "almost immediately" -- about a hundred million years -- after the Earth's formation, what has happened to it because if this cooling?

There is also the effect of the Earth's mass increase due to its gravitation pulling cosmic dust as well as cosmic bodies falling onto it, which surpass the loss of mass through the atmosphere, thus slightly increasing the weight of crust and its pressure against the mantle.

Obviously, the crust is too (relatively) thin and weak to allow emptinesses/cavities/hollows appearing under itself because of the shrinkage of the inner matter, so it was breaking in places thus forming continents that float over the mantle and "falling" downwards a bit instead, right?

Or the additional volume because of the cooling did not really change the Earth's effective/average diameter at all since the mantle (and deeper layers) was pushing against the crust with high pressure in the first place so the decrease of volume of the Earth's innards did not happen and it all only ended up decreasing the pressure against the crust, thus decreasing volcanic activity instead of changing the effective/average diameter of the planet?

Thanks in advance.

(The question was inspired by Dunno on the Moon scientific fiction novel, which is obviously unrealistic, but is fun to wonder about hypothetically in terms of real-life physics.)


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