Why Dont The Oceans Become Fresh Water Eventually

[S2Mike]

With the polar ice caps melting and fresh water pouring in from rivers all over the world, Will the oceans become fresh water or just very slightly salty?

[66comanche]

More to the point, with the amount of beer/cider/spirits pouring out of our pissers, into the rivers and then into the sea, won't it become alcohol?

[mywifeshusband]

The sea evaporates pure water into clouds leaving the salt behind. Rain falls out the sky and the water filters through rocks etc. picking up a little bit of salt on the way. Flows into a river, flows into the sea, evaporates as pure water leaving that little bit extra salt behind. ad infinitum. This is how I understand it. (Failed Geography O level)

[bigandclever]

Water evaporates and leaves behind some mineral residue. The water then rains back down again, passes through rocks dissolving minerals along the way. This water is then passed by rives back to the oceans where it evaporates again, leaving the minerals behind. Also underwater volcanoes dissolve the earth's crust and that releases minerals into the oceans. Repeat for a looooooooong time.

Either that or millions of years of fish spunk; scientists are divided.

[Brigand]

In my slightly inebriated state (roll on the night on the town!) that does make sense.

After all, rainfall is fresh, rivers, lakes etc is fresh, all of which pour into the sea.
Although the sea is very salty and will take a colossal amount of diluting, unless there is a source of salt replenishing the seas, surely they would become fresh water eventually?

I'm sure someone in a better frame of mind will be along to tell us though...

[Brigand]

bigandclever said:

Water evaporates and leaves behind some mineral residue. The water then rains back down again, passes through rocks dissolving minerals along the way. This water is then passed by rives back to the oceans where it evaporates again, leaving the minerals behind. Also underwater volcanoes dissolve the earth's crust and that releases minerals into the oceans. Repeat for a looooooooong time.

Either that or millions of years of fish spunk; scientists are divided.

And there he is to tell us.

[Ikemi]

No, neither.

[king arthur]

S2Mike said:

With the polar ice caps melting and fresh water pouring in from rivers all over the world, Will the oceans become fresh water or just very slightly salty?

You have to bear in mind that this is where fish have sex...

[0a]

[Flibble]

Brigand said:

In my slightly inebriated state (roll on the night on the town!) that does make sense.

After all, rainfall is fresh, rivers, lakes etc is fresh, all of which pour into the sea.
Although the sea is very salty and will take a colossal amount of diluting, unless there is a source of salt replenishing the seas, surely they would become fresh water eventually?

I'm sure someone in a better frame of mind will be along to tell us though...

Rainfall is fresh, rivers and lakes are not - they are slightly salty and that's where the salt in the sea comes from. The very slightly rivers flow into the sea, water evaporates and the salt concentration increases.

As for why the sea doesn't become super salty - salt is also lost from the sea by being absorbed by sea organisms, which then die and fall to the seabed without completely dissolving. They eventually form rocks which will then be uplifted and eroded by rain and rivers and the cycle completes.

Incidentally, if you pour a lot of river water into a smallish sea with high evaporation and not much sea life, you do get a very salty sea - the Dead Sea is an example of such.