Why are the oceans salty?

The salt in our oceans is the result of millions of years of minerals leaching and disolving from the solid earth. The major portion comes from rivers, while a good quantity of the salts are dissolved from rocks and sediments below the ocean floor, through volcanic vents. The weather is also responsible, to a lesser degree, as the rain deposits mineral particles into the oceans.

The sun's heat distills or vaporizes almost pure water from the surface of the sea, leaving the salts and minerals behind. The water returns to the ocean, via rivers or precipitation, to wash down more salt, which becomes ever more concentrated. This process is part of the continual exchange of water between the Earth and the atmosphere that is called the hydrological or water cycle.

First answer by Thatoneguy. Last edit by Khudukha. Contributor trust: 35 [recommend contributor]. Question popularity: 162 [recommend question]