Why is sea water salty
Sea water is just too salty for fresh water animals and fish to drink or survive in and the reason for that excessive salt content can be traced back to the ancient days when rocks first started to become eroded by the action of moving water on them. Therefore, the reasons for the sea’s saltiness are directly related to rock erosion that started millions of years ago and is still continuing today. Rain water contains carbonic acid in it because when it is up in the atmosphere, the water reacts with the atmospheric carbon dioxide. As this mixture of rainwater and carbonic acid comedown on the rocks, they get eroded both physically and chemically over the years. The chemical reaction between the acid in rain water and the rocks releases the salts that the rocks contain and they end up being carried away along with the moving water. The chloride and sodium ions along with other minerals and chemicals move with the water first into the rivers, and then finally into the larger seas and oceans. As the oceans and seas had been the final destinations for these ions, their concentration has increased over the millions of years for which this entire phenomenon has been occurring.
Not all the salt that ends up into the sea is allowed to accumulate however, because many of the marine animals require the salts within the sea and therefore they do use up a portion of the salt. Presently, the concentration of salt in sea water is roughly 3.5%, but this is a ratio which may not remain the same in the future. The water from the surface is however, not the only source that is responsible for the sea’s salty taste. Recent discoveries have shown that there are certain openings on the ridges of the oceans known as hydrothermal vents which are also responsible for adding salts and minerals to the ocean. As the ocean water gets into these cracks on the ocean surface, it becomes very hot and certain chemical reactions occur between the rocks in the crust and the sea water. The end result is that when the water comes back out again, its contents are somewhat changed and the volume of chemical content in the sea water is further increased. The reactions may increase or even decrease the salt content of the water as well. Another natural phenomenon which is similar to the aforementioned occurrence that also contributes to the sea’s strong and salty taste is volcanic activity under the sea. Submarine volcanic eruptions release a lot of chemicals and salts into the sea and the water reaches a very high temperature on coming in contact with these incredibly hot rocks from the core of the earth. The hot water reacts with the volatile rocks and again changes take place in the chemical structure of both the sea water as well as the rocks that it comes in contact with.