How the sea maintaines its salt level?

Answer 1

Based on geological evidance, the oceans have been around about 3.5 bllion years, as well chemical and geological evidance indicates the ocean's salt balance has remained largely unchanged for 1.5 billion years. There is about 5x10622g of dissolved mateial to give an ocean of 36 ppt salinity (parts per thousand) Each year the runoff from land adds another 2.5x10^15 g, or 0.000005% the total. So for 3.5 billionyear, the accumulation must be offset somehow! Sea-spray, evaporites (areas of sea left to evaporate off the wter & leave salt deposits), salt ions react with one another to form insoluble substances which precipitate out, Biology: concentrate salts becoming sediments, ot to mention that evaporation minus (precipitation + runoff) must balance out over the globe (barring ice accumulation) the salt balance is regulated.

Answer 2

The others don't seem to understand your question. You are wondering why the sea doesn't get increasingly salty as the rivers keep on adding dissolved salts to it, right?

Well, it does get saltier. It just doesn't get saltier at a rate we can easily notice. Unless there is some mechanism for removing sodium from the water (the way coral removes calcium), the water will get saltier and saltier until everything dies.

Projecting backward the rate at which sodium accumulates in the ocean, it appears that the oceans were fresh water around twelve thousand years ago, or so.

So, what happened? Either the earth is a lot younger than we thought, or there had to be a massive amount
of salt added to the environment (perhaps in the form of a comet or asteroid hitting the earth) back then.

But that would imply that all the living creatures in the sea evolved to adapt to life with a much higher salt content in the ocean in a very short time!

It could have happened that way... we have no way of being able to tell whether fossil sharks from bazillions of years ago swam in fresh water or salt water, for example. The mechanical characteristics of the two types of water are similar enough that the shape of the fish would not have had to change much, if at all....

So, which way do you think it happened...?

Answer 3

The salt concentration should be much higher than it is now if salt just kept accumulating from land runoff. However, the salt concentration of the oceans has been constant for millions of years. The reason is that salt is precipitated because of evaporation and also falls out in the form of dead sea creatures, especially plankton. Once on the bottom the salt is subducted back into the mantle when one tectonic plate slides beneath another.

Answer 4

teh water cycle, because when evaporation occurs, only the water evaporates leaving the salt, = the same amount of salt,

a little salt from a hurricane isnt goin to make a diference, and it will eventually reach the ocean later in time

Answer 5

We have the same percentage of salt in our bodies as the ocean has.i guess the sea maintains it much as we do.... naturally.

Answer 6

silly question. where would all that salt go? if the salt stays and no water is permanently added or subtracted from the earth. then it has to maintain the same salinity.

Answer 7

I support cdf-rom in his/her answer. This is one evidence to support a young earth. Hence, no macroevolution, since that takes millions of years.

More salt enters the sea than leaves it. So, the salt content is gradually increasing. In the case of the Dead Sea, the salt content is so high that there is hardly anything living in it (the name fits!) and it is virtually impossible to drown in it because its density is high.

Answer 8

Because the water is evaporating,and the salt remains.

Answer 9

by evaporation

Answer 10

its gods creation!!! thats how it flows...