Theosophy why the water in the sea is salty Blavatsky. Why is sea water salty? Where does salt come from? More curious versions of salt formation in the seas

Everyone who was on the beach could make sure that the water in the sea tasted salty. But where does salt come from if it enters the ocean fresh water through rains, rivers and ? Why the sea is salty and has it always been so - time to figure it out!

How is the salinity of water determined?

Salinity refers to the content of salts in water. Salinity is most commonly measured in ppm » (‰). A ppm is one thousandth of a number. Let's give an example: the salinity of water is 27 ‰, which means that one liter of water (that's about 1000 grams) contains 27 grams of salt.

Fresh water is considered to be water with an average salinity of 0.146 ‰.

Medium the salinity of the oceans is 35 ‰. Sodium chloride, also known as table salt, makes the water directly salty. Among other salts, its share in sea water is the highest.

The most salty sea is the Red Sea. Its salinity is 41‰.

Where does the salt in the seas and oceans come from

Scientists still disagree about whether sea water was originally salty or acquired such properties over time. Depending on the versions, different sources of the appearance of salts in the World Ocean are also considered.

Rains and rivers

Fresh water always has a large number of salts, and rainwater is no exception. It always contains traces of substances dissolved in it, which were captured during the passage through the atmosphere. Getting into the soil, rainwater washes away a small amount of salts and eventually brings them to lakes and seas. From the surface of the latter, water evaporates intensively, falls again in the form of rain and brings new minerals from the land. The sea is salty because all the salts remain in it.

The same principle applies to rivers. Each of them is not completely fresh, but contains a small amount of salts captured on land.

Confirmation of the theory - salt lakes

Evidence that salt comes through rivers are the most saline lakes: the Great Salt Lake and the Dead Sea. Both are about 10 times saltier than sea water. Why are these lakes salty?, while most of the world's lakes are not?

Usually lakes are temporary storages for water. Rivers and streams bring water to lakes, and other rivers carry it away from these lakes. That is, water enters from one end, and leaves from the other.

The Great Salt Lake, the Dead Sea and other salt lakes have no outlets. All the water that flows into these lakes leaves only by evaporation. When the water evaporates, the dissolved salts remain in the water bodies. Thus, some lakes are salty because:

rivers carried salt to them;
the water in the lakes evaporated;
salt remained.

Over the years, the salt in the lake water has accumulated to its current level.

Interesting fact: The density of salt water in the Dead Sea is so high that it practically pushes a person out, preventing him from sinking.

The same process made the seas salty. Rivers carry dissolved salts to the ocean. Water evaporates from the oceans to fall again as rain and replenish rivers, but the salts remain in the ocean.

hydrothermal processes

Rivers and rains the only source of dissolved salts. Not so long ago, on the ocean floor were discovered hydrothermal vents. They represent places where sea water seeped into the rocks. earth's crust, has become hotter and is now flowing back into the ocean. Along with it comes a large amount of dissolved minerals.

underwater volcanism

Another source of salts in the oceans is underwater volcanism - volcanic eruptions underwater. It is similar to the previous process in that sea water reacts with hot volcanic products and dissolves some mineral components.

Why is the sea salty and where does the salt come from? This is a question that has interested people for a long time. There is even a folk tale about this.

As folklore explains

Whose legend is this, and who exactly invented it, is no longer known. But among the peoples of Norway and the Philippines, it is very similar, and the essence of the question of why the sea is salty, the tale conveys as follows.

There were two brothers - one rich, and the other, as usual, poor. And no, to go and earn bread for his family - the poor goes for alms to the stingy rich brother. Having received a half-dried ham as a “gift”, the poor, in the course of some events, falls into the hands of evil spirits and exchanges this very ham for a stone millstone, modestly standing outside the door. And the millstone is not simple, but magical, and can grind everything that the soul pleases. Naturally, the poor man could not live quietly, in abundance, and not talk about his miracle find. In one version, he immediately built a palace for himself one day, in another, he threw a feast for the whole world. Since everyone around him knew that just yesterday he lived in poverty, those around him began to ask questions about where and why. The poor man did not consider it necessary to hide the fact that he had a magic millstone, and therefore many hunters appeared to steal it. The last such person was a salt merchant. Having stolen the millstone, he did not ask him to grind money, gold, overseas delicacies, because having such a “device”, one could no longer engage in the salt trade. He asked to grind salt for him so that he would not have to swim behind her across the seas and oceans. A miracle millstone started up, and it ground so much salt for it that it sank the ship of the unfortunate merchant, and the millstone fell to the bottom of the sea, continuing to grind salt. This is how people explained why the sea is salty.

Scientific explanations of the fact

Rivers are the main source of salts in the seas and oceans.

Yes, those rivers that are considered fresh (more correctly, less salty, because only distillate is fresh, that is, devoid of salt impurities), in which the salt value does not exceed one ppm, make the seas salty. This explanation can be found in Edmund Halley, a man known for the comet named after him. In addition to space, he studied more mundane issues, and it was he who first put forward this theory. Rivers constantly bring a huge amount of water, along with small impurities of salts, into the depths of the sea. There, water evaporates, but salts remain. Perhaps earlier, many hundreds of thousands of years ago, the ocean waters were very different. But they add another factor that can explain why the seas and oceans are salty - volcanic eruptions.

Chemicals from volcanoes that bring salt to the sea

At a time when the earth's crust was in a state of constant formation, there were frequent ejections of magma with an incredible amount of various elements to the surface - both on land and under water. Gases, indispensable companions of eruptions, mixing with moisture, turned into acids. And those, in turn, reacted with the alkali of the soil, forming salts.

This process is happening now, because seismological activity is much lower than it was millions of years ago, but still present.

In principle, the rest of the facts explaining why the water in the sea is salty have already been studied: salts enter the seas from the soil by means of movement by precipitation and winds. Moreover, in each open reservoir, the chemical composition of the main terrestrial liquid is individual. When asked why the sea is salty, Wikipedia answers in the same way, only emphasizing the harm of sea water for the human body as drinking water, and the benefits when taking baths, inhaling and the like. No wonder sea salt is so popular, which is even added to food instead of table salt.

The uniqueness of the mineral composition

We have already mentioned that the mineral composition is unique in each reservoir. Why the sea is salty and how much it is, decides the intensity of evaporation, that is, the temperature of the wind on the reservoir, the number of rivers that flow into the reservoir, the richness of flora and fauna. So, everyone knows what the Dead Sea is, and why it is called that.

Let's start with the fact that it is incorrect to call this body of water a sea. It is a lake because it has no connection with the ocean. They called him dead because of the huge proportion of salts - 340 grams per liter of water. For this reason, no fish is able to survive in the reservoir. But as a hospital, the Dead Sea is very, very popular.

Which sea is still the most salty?

But the right to be called the most salty belongs to the Red Sea.

There are 41 grams of salts in a liter of water. Why is the Red Sea so salty? Firstly, its waters are replenished only by precipitation and the Gulf of Aden. The second is also salty. Secondly, the evaporation of water here is twenty times higher than its replenishment, which is facilitated by the location in the tropical zone. If it were a little further south, closer to the equator, and the amount of precipitation typical for this zone would drastically change its content. Due to its location (and the Red Sea is located between Africa and the Arabian Peninsula), it is also the warmest sea among all available on planet Earth. Its average temperature is 34 degrees Celsius. The whole system of possible climatic and geographical factors has made the sea what it is now. And this applies to any body of salt water.

The Black Sea is one of the unique compositions

For the same reasons, one can single out the Black Sea, whose composition is also peculiar.

Its salt content is 17 ppm, and these are not quite suitable indicators for marine inhabitants. If the fauna of the Red Sea strikes any visitor with its variety of colors and forms of life, then do not expect this from the Black Sea. Most of the "settlers" of the seas do not tolerate water with less than 20 ppm salts, therefore the diversity of life is somewhat reduced. But it contains many useful substances that contribute to the active development of unicellular and multicellular algae. Why is the Black Sea half as salty as the ocean? This is primarily due to the fact that the size of the territory from which river water flows into it exceeds the area of the sea itself by five times. At the same time, the Black Sea is very closed - only a thin strait connects it with the Mediterranean, but otherwise it is surrounded by land. Salt concentration cannot become very high due to intensive desalination by river waters - the first and most important factor.

Conclusion: we see a complex system

So why is the sea water salty? It depends on many factors - river waters and their saturation with substances, winds, volcanoes, precipitation, evaporation intensity, and this, in turn, affects the level and diversity of living organisms in it, both flora and fauna. This is a huge system big amount parameters that ultimately make up an individual picture.

Did you know that sailors who got lost in sea waters most often died of thirst? This is a paradox - after all, the ship is surrounded by thousands of tons of life-giving moisture! The fact is that the chemical composition of sea water does not suit our body, so it cannot be drunk. In addition, it has a specific taste - because of the salts dissolved in it. The question arises: how did they get there and why is the water in the sea salty?

The waters of the ocean contain almost all the elements of the periodic table. Most of all - hydrogen and oxygen, which are combined into water molecules. There are also impurities containing:

calcium;
magnesium;
bromine;
sulfur;
fluorine.

But the main mineral part is chlorine and sodium ions, that is, ordinary salt, which gives the water a salty taste. It remains to find out who salted the water in the seas.

How sea water was formed

Scientists have not yet found an answer to the question why sea water is salty and river water is not. There are two hypotheses for the formation of sea water. The main difference between them lies in the view of the beginning of this process. Some believe that the ocean became salty quite recently, while others are sure that this happened in the early stages of the planet's existence.

river infusions

The waters of rivers and lakes are also salty. But we do not feel this, since the content of sodium chloride in them is 70 times less than in the sea. According to the "river" hypothesis of the origin of sea water, dissolved impurities enter the ocean with the flow of rivers. The water in the sea gradually evaporates, but the minerals remain, so their concentration is constantly increasing. The process of salinization of the ocean, according to this group of scientists, continues for several billion years, as a result, the water becomes more and more salty.

However, studies conducted over many years show that the salt content in the world's oceans does not change for a long time, and the substances that enter it with river water can only maintain this value at the same level. In addition, this hypothesis does not explain the different composition of river and sea water: there are many carbonates in the rivers, and chlorides predominate in the sea.

Consequence of volcanic activity

Proponents of the second hypothesis believe that sea water was salty even when life on Earth did not yet exist. And the reason for this is volcanoes. During the formation of the earth's crust, many ejections of magma occurred. Volcanic gases contained compounds of bromine, fluorine and chlorine, which fell out as part of acid rain. As a result, an acidic ocean appeared on the planet.

Ocean acids began to react with alkaline elements of the solid rocks of the earth, giving rise to more stable compounds - salts. So, common salt for us was formed as a result of the interaction of perchloric acid from the ocean and sodium ions from frozen volcanic rocks.

Gradually, sea water became less and less acidic and acquired a salty taste. According to supporters of this theory, the ocean acquired modern properties 500 million years ago, when the Earth's surface was cleared of volcanic gases, and the composition of the water stabilized.

Then how to explain the disappearance of carbonates that come with the river current? This is the "handiwork" of marine life. They have learned to use these minerals to build the skeletons and shells that are necessary for the protection and mechanical support of the body.

In which sea it is impossible to drown

The salts that make up water can change its properties, including density. The higher it is, the more difficult it is to immerse in liquid. solid so it is easier to swim in sea water. From this point of view, many are interested in which sea has the most salty water.

The Dead Sea has the highest concentration of sodium chloride, which is actually a lake and is fed by the waters of the Jordan River. It is located between Israel and Jordan and is very attractive for tourists who want to relax and improve their health. Most of all, people like to swim there, as the high density of water does not allow you to drown.

The saltiest water in the world has a salinity index of 33.7%, which is almost 9 times higher than this indicator in the global ocean. This sea was called dead because of the absence of habitual inhabitants - algae and fauna. But many types of microscopic organisms live in it - fungi, omycetes and bacteria.

Why is the sea salty: Video

Water is one of the strongest solvents. It is able to dissolve and destroy any rock on the surface of the earth. Water flows, streams and drops gradually destroy granite and stones, while leaching of easily soluble minerals from them occurs. constituent parts. No strong rock can withstand the destructive effects of water. This is a long but inevitable process. The salts that are washed out of the rocks give the sea water a bitter-salty taste.

But why is the water in the sea salty, and fresh in the rivers?

There are two hypotheses for this.

Hypothesis one

All impurities dissolved in water are carried by streams and rivers to the seas and oceans. River water is also salty, only salts in it are 70 times less than in sea water. Water from the oceans evaporates and returns to the earth in the form of precipitation, while dissolved salts remain in the seas and oceans. The process of "delivery" of salts to the seas by rivers has been going on for more than 2 billion years - a time sufficient to "salt" the entire World Ocean.

The Kloota River Delta in New Zealand.
Here Kluta is divided into two parts: Matau and Koau,
each of which flows into the Pacific Ocean.

Sea water contains almost all the elements that exist in nature. It contains magnesium, calcium, sulfur, bromine, iodine, fluorine, copper, nickel, tin, uranium, cobalt, silver and gold are contained in small amounts. Chemists have found about 60 elements in sea water. But most of all, sea water contains sodium chloride, or table salt, which is why it is salty.

This hypothesis is supported by the fact that lakes that do not have a runoff are also salty.

Thus, it turns out that initially the water in the oceans was less salty than it is now.

But this hypothesis does not explain the differences in chemical composition sea and river water: chlorides (salts of hydrochloric acid), and in rivers - carbonates (salts of carbonic acid).

Hypothesis two

According to this hypothesis, the water in the ocean was originally salty, and the reason for this was not rivers at all, but volcanoes. Proponents of the second hypothesis believe that during the formation of the earth's crust, when volcanic activity was very high, volcanic gases containing chlorine, bromine and fluorine vapors poured acid rain. Thus, the first seas on Earth were... acidic. Entering into chemical reaction with solid rocks (basalt, granite), the acidic water of the oceans extracted alkaline elements from rocks - magnesium, potassium, calcium, sodium. Salts were formed that neutralized sea water - it became less acidic.

As volcanic activity decreased, the atmosphere was cleared of volcanic gases. The composition of ocean water stabilized about 500 million years ago - it became salty.

But where do carbonates disappear from river water when they enter the World Ocean? They are used by living organisms - to build shells, skeletons, etc. But chlorides, which prevail in sea water, they avoid.

At present, scientists have agreed that both of these hypotheses have the right to exist, and do not refute, but complement each other.

Almost every one of us, inadvertently opening his mouth while swimming in the sea and taking a sip of water, wondered why the sea is salty? Of course, one can be like the ancient Greeks, who believe that the waters of the seas and oceans are the tears of Poseidon. But now they do not believe in fairy tales, and a strictly scientific justification of the reasons for the appearance of salt in sea waters is required.

Theories of salinity of the seas

Researchers of this long-standing problem are divided into two camps, offering specific theories.

The salinity of the seas was acquired gradually

This was facilitated by the natural water cycle. Precipitation, acting on the rocks, washed out minerals from it, which fell into the river systems. And from the rivers, water saturated with salts already entered the seas. The river flows themselves also contributed to the leaching of salts from soils and rocks.

Then the indefatigable Sun set to work. Under its hot influence, the evaporation of water, which no longer contains salts, occurred. Distilled moisture fell as rain and snow on the surface of the planet and continued its work to saturate the seas with salts.

The process continued for many millions of years, salt accumulated in sea waters, acquiring exactly the consistency that we now observe. Everything is simple and quite logical. However, there are some inconsistencies in this theory.

For some reason over the past half a billion years, the concentration of salts in sea waters has not has changed. But precipitation and rivers are as active as before. This discrepancy can be explained as follows. Salts supplied by rivers to the subsoil do not dissolve in them, but settle on the bottom surfaces. Various rocks and stony formations are formed from them.

The sea waters were salty from the start

During the formation of the earth's crust, powerful volcanic activity was observed. Thousands of volcanoes emitted into the atmosphere gigantic quantities of all kinds of substances, among which were:

chlorine;
bromine;
fluorine.

Acid showers constantly fell on the earth's surface, contributing to the birth of the seas.

Their oxidized waters interacted with rocks and pulled out of them:

potassium;
sodium;
magnesium;
calcium.

As a result, salts were obtained, with which the waters were saturated. But 500 million years ago, this process ended.

More curious versions of salt formation in the seas

The search for versions of the appearance of salt and fresh water does not stop. At the moment, two are the most interesting.

Our planet was formed in this form - the seas are salty, and the rivers are fresh. If it weren't for river currents, rivers could also become salty, but fortunately the seas cannot flow into them.
Animals have contributed. For a long time the waters were salty everywhere. But animals very actively consumed it from rivers and lakes in order to receive the necessary chemical elements for the development of their organisms. For many hundreds of millions of years, the rivers have lost all their reserves of sodium chloride. But this version is more entertaining.

Features of sea water

For people, fresh water is familiar and beneficial features its obvious. But sea waters have their own characteristics.

It is absolutely not suitable for drinking. The content of salts and other minerals very large. They can only be removed from the body with more water. But if you carry out the desalination of such water, then it is quite possible to drink it.
In some countries, it is the maritime salt water used for household purposes. For example, in drain sewer systems.
The benefits of sea water for healing have long been known. It is used in the form of baths, rinses, inhalations. It helps fight diseases respiratory tract relieves muscle tension. Water with a high salt content also exhibits antibacterial properties.