Why is seawater salty?

Everyone knows that seawater is salty. This is because most rivers and streams empty themselves into the sea. Rivers are strewn with rock and plant debris. These rocks contain many minerals and salts (especially sodium chloride) which dissolve in the water, a considerable amount of salt gets dissolved in the sea water.

When these waters evaporate due to the heat of the sun, they leave the salt behind. The evaporated water is brought back to the land in the form of rain, and the rivers carry the water again to the sea. As this cycle is repeated, the amount of salt increases, but the water content does not.

Will the oceans continue to become saltier? No, that's not likely. In fact, the salt content has reached a steady state. Dissolved salts are being removed from seawater to form new minerals at the bottom and the ocean as fast as rivers and hydrothermal processes are providing new salts.

Did you know that fresh water is not entirely free of dissolved salt? Of course, we cannot taste this salt because its concentration is too low.

Tags: seawater, sea, watervapor