Why is sea water salty

From time to time we are confronted with some questions related to our planet that have not yet been answered. For example, the presence of salt in the water of the oceans. How did she get there?

The scientific justification for the appearance of salt water in the sea was laid by the work of Edmund Halley in 1715. He suggested that salt and other minerals were washed out of the soil and transported to the sea by rivers. Having reached the ocean, the salts remained and gradually concentrated. Halley noticed that most of the lakes that have no water connection with the oceans have salt water.

Halley's theory is partly correct. In addition, it should be mentioned that sodium compounds were washed out of the ocean floor in the early stages of their formation. The presence of another element of salt, chlorine, is explained by its release (in the form of hydrochloric acid) from the bowels of the Earth during volcanic eruptions. Sodium and chlorine ions gradually became the main components of the salt composition of seawater.

But we don't know if we can explain the presence of such a huge amount of salt in the oceans. If all the oceans were dried up, the remaining salt could be used to build a wall 230 km high and almost 2 km thick. Such a wall would be able to circle the entire globe along the equator.

Or another comparison. The salt of all dried up oceans is 15 times larger than the entire European continent by volume!

The common salt we use on a daily basis is obtained from sea water, salt springs or from the development of rock salt deposits. Sea water contains 3-3.5% salt. Inland seas such as the Mediterranean Sea and the Red Sea contain more salt than the open seas. Dead Sea, occupying only 728 sq. km., contains approximately 10 523 million tons of salt. There is so much salt in it that it is almost impossible to drown in such water, since the density of the water has increased due to the salts.

On average, a liter of sea water contains about 30 g of salt. Rock salt deposits in various parts of the earth were formed many millions of years ago as a result of the evaporation of sea water. For the formation of rock salt, it is necessary that nine-tenths of the volume of sea water evaporate; It is believed that inland seas were located at the site of modern deposits of this salt. They evaporated faster than new seawater came in, and so rock salt deposits appeared.

The main amount of edible salt is extracted from rock salt. Usually, mines are laid to the salt deposits. Clean water is pumped through the pipes, which dissolves the salt. This solution rises to the surface along the second pipe.

In Hong Kong, seawater is widely used in toilet flush systems. More than 90% of them use seawater for flushing in order to save fresh water. This practice began in the 1960s and 1970s, when the extraction of fresh water became a problem for the inhabitants of the former British colony.

Sea water can be drunk without harm in small quantities for 5-7 days.