Why is the sea water so salty? What makes sea water salty?

When asking yourself the question “why is the water in the sea salty”, you need to remember that salt accumulates in drainless reservoirs, and since the oceans have nowhere to “drain”, the accumulation of salt in sea water will be inevitable.

Salt in sea water appeared billions of years ago, during the era of the formation of the world's oceans. The source of salt in sea water is, on the one hand, the ocean floor, which for many centuries “feeded” sea water with chlorides through volcanoes and organic sediments, and on the other hand, rivers that carried washed rocks into the world ocean.

Salt content in sea and ocean water is not uniform. So, for example, in the Gulf of Finland of the Baltic Sea, the water is practically fresh, due to the strong isolation of the Baltic Sea from the world ocean. The salt content in the waters of the Gulf of Finland does not reach 30 grams per liter. But if we look at the Red Sea, we will see that the water in it is so salty that not all fish can survive there. Salt content in the Red Sea reaches 40 grams per liter. Both of these examples are extreme cases. In general, the salinity of the world's oceans is 35 grams of salt per liter of water. The basis of sea salt is sodium chloride, known to us as table salt.