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.
The reason water is concentrated in oceans isn’t specifically due to continents existing. Salt doesn’t evaporate so all rain is fresh water. That fresh water falls. When it falls over land it flows to the lowest point it can go. This leads to all flowing water flowing towards oceans and seas. Salt won’t travel upstream. Ergo salt simply stays in oceans and seas.
Now consider a world with no land. This wouldn’t really differ from a single ocean on earth. Currents and waves will move in all directions at some point which should mix the salt all around. You could get some differences if there were ice caps or icebergs. Those could behave similarly to continents depending on size.