If water flowing over continents in rivers is what concentrates salt in our ocean, would a planet that has always been covered in water just be freshwater? The water is just sitting there, not eroding through salts.
If water flowing over continents in rivers is what concentrates salt in our ocean, would a planet that has always been covered in water just be freshwater? The water is just sitting there, not eroding through salts.
This is all very interesting and pertinent. I was wondering about the hadean period, and whether you could actually get to an ocean world without first having continents with a water cycle. I don’t know enough about planetary formation to conclude further. Thanks for pointing me to the hadean period, I will read more about that.
You might misunderstand my comment about the dead sea. The dead sea actually precipitates salt crystals onto the bottom of the sea. No land is required in this strange process. I don’t think it’s clear to say whether this happens because of the extreme salinity of the dead sea, or if the extreme salinity just makes it the only place we observe this rapid desalination on human time scales. I offered this as perhaps the most striking example that salts dissolved in water are not necessarily a stable state on a timeline of billions of years.
As far as I can tell, salt precipitation in the Dead Sea is a result of evaporation. As the concentration of various ions increases, you eventually reach a point where water can not hold any more salt in it. If there’s too much, the excess gets pushed out into the solid phase as salt crystals.
It’s all about the solubility of each compound, which depends on all sorts of things such as temperature, pressure, pH, other ions, etc. As the conditions change, solubility changes, excess salts get precipitated and the solution finds a new equilibrium.