One theory states that the sea is salt because of the mid-Ocean rift. Fresh basalt flows up through the rift along with juvenile water; water that is made up of many of the components of sea water including chlorine, bromine, iodine, and many other molecules. Also some salts get into the ocean through volcanoes and even fresh water rivers carries salt into the sea. The sea is composed of many other things.
Scientist over the years has conducted many experiments to prove not only of what the sea is made have but also many other things. In 1715 a scientist named Edmund Halley had a theory to prove the age of the ocean by the rate of salt that is transported through the rivers. In 1889 a scientist by the name of John Joly decided to test this theory and found out the sea is approximately ninety million years old. Also another scientist by the name of Antoine Laurent Lavoisier conducted the first analysis of seawater two hundred years ago.
Another concept developed by John Murray in the nineteenth century states that the weight is never determined but instead the total amount of chloride ion is carefully measured and a total for all other ions is computed by applying the constancy of relative proportions. Also A. M. Marcet, Johann Forchammer, and Wilhelm Dittmar have researched this theory. Now in the last forty years geochemist have really began looking into the chemistry of the ocean. Not only can the chemistry tell us what the sea is made have but also a history of the sea.
For example the salinity of the sea has not really change in its history. The reason the seas salinity has not changed is because of its strong buffering zones. Todays scientist has also begun to look at rain as it reaches the sea. One thing that scientist have not been able discover is the never- ending numbers of organisms that live in the sea. Some of Earths most mysterious and miraculous orgasms live in the sea. One thing that you can conclude is that the sea is a very complex entity, and although we have discovered and learned many things about the sea there is still so much more to learn.