It appears that Mercury shows some cracks on its surface that were not caused by moving tectonic plates but by shrinking due to the inner metal core cooling.

The Earth is also cooling down, but are there any signs that shows effects of this cooling of the core, or are they masked by tectonic plate movements, erosion, or other effects?

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    $\begingroup$ They are overwhelmingly masked by plate tectonics. The slow contraction of the Earth is essentially taken up by ductile deformation in the mantle and by the movement of tectonic plates. $\endgroup$ – bon Feb 8 '17 at 21:37
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    $\begingroup$ @bon sounds right. Also, Earth's core is much larger so it cools slowly, and it's also better insulated so I guess that makes cooling also slower. Note that most of Mercury's volume is taken up by the core, whereas it's not for the Earth. I guess this also has something to do with why doesn't show up on Earth. $\endgroup$ – Gimelist Feb 8 '17 at 23:07
  • $\begingroup$ Sounds like good information you guys give. Fleshing it out into a complete answer would be great! $\endgroup$ – JeopardyTempest Feb 11 '17 at 8:30