That is cool.
Very thought provoking, this clock will run longer than the Pyramyds of Egypt are old , could be running when the pyramids have collapsed.
Or an earthquake could scramble its gears , or a vandal could throw sand in the gears, a monkey wrench onto the pendlum or a theif could steal some of the metal.
Remember those Buddahs in Afganistan? I think intolerance is a worser danger to this clock than earthquake.
And of course after the entire mountain has eroded into the sea to become beach sand Neil Armstrong's footprint is quite likly to still be on the moon at the foot of the Eagle.