By “smoothing out” I mean flattening all mountains and filling all trenches so that the entire earth has exactly the same radius everwhere. Water naturally spreads out equally on such a surface, so how high would the water level be?
By “smoothing out” I mean flattening all mountains and filling all trenches so that the entire earth has exactly the same radius everwhere. Water naturally spreads out equally on such a surface, so how high would the water level be?
You’ve forgotten about tides.
Tides are in the dimension of metres, the global ocean would be kilometres deep.
Edit: also, due to earth’s rotation, the ocean would be slightly deeper around the equator than at the poles.