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.

  • over_clox@lemmy.world
    13·
    25 days ago

    Disclaimer: Not an expert.

    Thoughts: I think this would largely depend on multiple factors, such as the overall composition of the planet, a hypothetically almost perfectly spherical core underneath the water, and not having a moon to shift the water tides around.

    And even then, solar gravitational tides are a thing, so the water would most likely still move. Also, I’m pretty sure there’s no perfectly spherical planet, so I assume there would still be some sort of underwater erosion going on.

    All speculation though.

    • HotDayBreeze@lemmy.worldOP
      2·
      25 days ago

      I was trying to figure out how much underwater erosion there is but if you compare the sandy and silty bottom of the ocean to like, Utah, it seems like continental erosion is orders of magnitude more significant.

      Conversely, we know oceans deposit all sorts of stuff at their bottoms, which makes me think there is a small amount of salt being deposited. Would that cancel out significant underwater erosion?

      Similarly, if underwater erosion was a big deal, wouldn’t old lakes (in geological time) be notably saltier than young lakes? But the only salty lakes we have primarily lose all their water through evaporation, basically ultra concentrated river water.