Why is there salty water in the sea? Why is the water in the sea salty Theosophy why is the water in the sea salty Blavatsky.

Did you know that sailors 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 is not suitable for our body, so it cannot be drunk. In addition, it has a specific taste - due to the salts dissolved in it. The question arises: how did they get there and why is the water in the sea salty?

Ocean waters contain almost all 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 made up of chlorine and sodium ions, that is, ordinary salt, which gives the water a salty taste. It remains to be seen who salted the water in the seas.

How sea water was formed

Scientists still have not found an answer to the question of 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 is the way they look at 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 don’t feel this, since the sodium chloride content 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 ocean salinization, according to this group of scientists, has been going on for several billion years, resulting in water becoming 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 substances entering 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: rivers have a lot of carbonates, while chlorides predominate in the sea.

Consequence of volcanic activity

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

The ocean's acids began to react with the alkaline elements of the hard rocks of the earth, giving rise to more stable compounds - salts. Thus, table salt, which is familiar to us, was formed as a result of the interaction of perchloric acid from the ocean and sodium ions from frozen volcanic rocks.

Gradually, the sea water became less acidic and acquired a salty taste. Proponents of this theory believe that the ocean acquired its 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 flow? This is the “work of the hands” of marine inhabitants. They learned to use these minerals to build skeletons and shells, which are necessary for the protection and mechanical support of the body.

In which sea is it 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 a solid body in liquid, so it is easier to swim in sea water. From this point of view, many are interested in which sea has the saltiest water.

The Dead Sea, which is actually a lake and is fed by the waters of the Jordan River, has the highest concentration of sodium chloride. It is located between Israel and Jordan and is very attractive to tourists who want to relax and improve their health. Most of all, people like to swim there, since the high density of the water prevents drowning.

The saltiest water in the world has a salinity index of 33.7%, which is almost 9 times higher than that in the world's oceans. This sea was called dead due to the absence of its usual inhabitants - algae and fauna. But many types of microscopic organisms live in it - fungi, omycetes and bacteria.

Why is the sea salty: Video

In contact with

Composition of sea water

To find out why salty sea, it is necessary to understand the composition of sea water. It contains almost the entire periodic table. The liquid is saturated with iodine, fluorine, bromine.

But the basis of the composition is chlorine and sodium. Sodium chloride is ordinary salt. This is what makes the water salty.

But such a solution brings great benefits to the skin. Through them, salty water has a beneficial effect on the human body as a whole.

Where does salt come from in the sea?

Why is the water in the sea salty?

Conclusion

Thus, sea water is salty due to several factors. All hypotheses are scientifically substantiated and true. And although fresh rivers flow into the seas, this does not in any way reduce their salinity level. Its degree depends on several factors. Depth is key and temperature. The Baltic Sea is considered the least saline, and the Red Sea has the highest degree of salinity.

Having visited the beach for the first time, the child asks his parents: why is the water in the sea salty? This simple question baffles adults. After all, everyone knows that a bitter aftertaste will definitely remain on the lips and the whole body. Why is the sea salty? We begin to reason: fresh rivers flow into this part of the World Ocean. So it can't taste that bad! But you can’t go against the facts: the water is not fresh. Let's figure out at what stage the initial composition of H2O changes.

Why is the salinity increased?

There are several theories about this. Some scientists believe that salt remains from the evaporated water of flowing rivers, others - that it is washed out of rocks and stones, others associate this compositional feature with the action of volcanoes... Let's begin to consider each version in order:

The reservoir becomes salty from the water of the rivers that flow into it. Strange pattern? Not at all! Although river moisture is considered fresh, it still contains salt. Its content is very small: seventy times less than in the vast depths of the World Ocean. Therefore, flowing into a large body of water, rivers desalinate its composition. But the river water gradually evaporates, but the salt remains. The volumes of impurities in the river are small, but over billions of years a lot of them accumulate in sea water.

Salts flowing from rivers into the sea settle on its bottom. From them, huge blocks of stone and rocks are formed on the ocean floor over thousands of years. Year after year, the current destroys any stones, leaching easily soluble constituent substances from them. Including salt. Of course, this process is long, but inevitable. Particles washed out of rocks and rocks give the ocean an unpleasant, bitter taste.

Underwater volcanoes release many substances into the environment, including salts. During the formation of the earth's crust, volcanic activity was very high. They released acidic substances into the atmosphere. Frequent acid rain formed seas. Accordingly, at first the water in the constituent parts of the ocean was acidic. But the alkaline elements of the soil - potassium, magnesium, calcium, etc. - reacted with acids and formed salts. Thus, water in various places of the ocean acquired the characteristics that are now familiar.

Other assumptions known today are related

• with the winds bringing salt into the water;
• with soils, passing through which fresh liquid is enriched with salts and enters the ocean;
• with salt-forming minerals located under the ocean floor and supplied through hydrothermal vents.

It is probably correct to combine all the hypotheses in order to understand the ongoing process. Nature gradually built all its ecosystems, closely intertwining things that were incompatible at first glance.

Where is the highest concentration of salt?

Sea water is the liquid that is most abundant on earth. It’s not for nothing that many people associate vacations primarily with the beach and coastal waves. Surprisingly, the mineral composition of the liquid in different bodies of water never coincides. There are many reasons for this. For example, salinity depends on the intensity of fresh water evaporation, the number of rivers, types of inhabitants and other factors. Which sea is the saltiest?

The answer is given by statistics: the Red Sea is rightfully called the saltiest. One liter of its water contains 41 grams of salts. If we compare with other reservoirs, then in a liter of liquid from the Black there are 18 grams of various salts, in the Baltic this figure is even lower - 5 grams. The chemical composition of Mediterranean is 39 grams, which is still lower than the above characteristics of Red. In ocean water - 34 grams.

Reasons for the unique feature of the Red Sea:

On average, about 100 mm of precipitation falls above the surface per year. This is very little, considering that about 2000 mm of water evaporates per year.

No rivers flow into this reservoir; it is replenished only by precipitation and waters from the Gulf of Aden. And its water is also salty.

The reason is also the intensive mixing of water. In winter and summer, the layers of liquid change. Evaporation occurs in the upper layer of water. The remaining salts fall down. Therefore, the salinity of water in this part of the water expanse increases significantly.

The Dead Sea is sometimes called the saltiest. Its waters contain 340 grams of salt per liter of water. That’s why it’s dead: the fish die in it. But some features of this body of water do not allow it to be considered a sea: it does not have access to the ocean. Therefore, it is more correct to call this body of water a lake.

Almost each of us, having carelessly opened our mouths while swimming in the sea and taken a sip of water, wondered why the sea is salty? Of course, you can be like the ancient Greeks, who believe that the waters of the seas and oceans are the tears of Poseidon. But now they don’t believe in fairy tales, and a strictly scientific substantiation of the reasons for the appearance of salt in sea waters is required.

Theories of sea salinity

Researchers on this long-standing problem fall into two camps, proposing specific theories.

The salinity of the seas gradually increased

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

Then the tireless Sun began to work. Under its hot influence, water evaporated, no longer containing salts. Distilled moisture fell as rain and snow on the surface of the planet and continued its work of saturating 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 is some inconsistency in this theory.

For some reason Over the past half a billion years, the concentration of salts in sea waters has not changed. But rainfall and rivers are as active as ever. This discrepancy can be explained as follows. Salts delivered by rivers to the subsoil of the sea do not dissolve in them, but settle on the bottom surfaces. From them various rocks and rocky formations are formed.

Sea waters have been salty from the very beginning

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

• chlorine;
• bromine;
• fluorine.

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

Their oxidized waters interacted with rocks and pulled out from 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 interesting versions of salt formation in the seas

The search for versions of the appearance of salty and fresh waters does not stop. At this time, two are the most interesting.

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

Features of sea water

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

1. It is absolutely not suitable for drinking. The content of salts and other minerals in it is very high. They can only be removed from the body with more water. But if such water is desalinated, then it is quite drinkable.
2. In some countries, sea salt water is used for domestic needs. For example, in drainage sewer systems.
3. The benefits of sea water for treatment have long been known. It is used in the form of baths, rinses, and inhalations. This helps fight respiratory diseases and relieves muscle tension. Water with a high salt content also exhibits antibacterial properties.

The salinity of the waters of some known seas is as follows (at 0/00):

• Mediterranean – 39;
• Black – 18;
• Karskoe – 10;
• Barentsevo – 35;
• Red – 43;
• Caribbean - 35.

Such a disproportionate salt content in the waters of different seas is influenced by specific factors:

• drainage of rivers and streams flowing into them;
• precipitation water;
• transformation of sea ice;
• vital activity of all kinds of marine organisms;
• plant photosynthesis;
• bacteriological activity.

Now you know why the sea is salty!

Water covers a large area of ​​our planet. The vast majority of this water is part of the seas and oceans, so it is salty and unpleasant to the taste. According to the server "Ocean Service" 3.5% of the oceans are made up of sodium chloride or table salt. This is tons of salt. But where does it come from and, therefore, why is the sea salty?

It is important to know!

For 4 billion years, rain waters the earth, rainwater penetrates into the rocks, from where it finds its way into. It carries dissolved salt with it. Over the course of geological history, the salt content of the sea gradually increases.

The Baltic Sea, due to low water temperatures, contains 8 times less salt than, for example, the Persian Gulf. If the water from all the oceans evaporated today, the remaining salt would form a coherent layer 75 m high around the world.

Where does the salt in the sea come from?

Yes, some of the salt enters the water directly from the seabed. At the bottom there is a whole series of salt-containing stones, from which salt penetrates into the water. Some of the sodium chloride also comes from volcanic valves. However, according to the BBC, most of the salt comes from the mainland.

Therefore, sodium chloride from land is the main reason why the sea is salty.
Each kilogram of sea water contains on average 35 g of salt. Most of this substance (about 85%) is sodium chloride, the well-known kitchen salt. Salts in the seas come from several sources:

• The first source is the weathering of rocks on the mainland; when the stones get wet, they wash away salts and other substances that rivers carry into the seas (rocks on the seabed have exactly the same effect);
• Another source is explosions of underwater volcanoes - volcanoes release lava into the water, which reacts with seawater and dissolves certain substances in it.

Water also penetrates into cracks that lie deep on the ocean floor in areas called mid-ocean ridges. The rocks here are hot and there is often lava at the bottom. In the cracks, the water heats up, due to which it dissolves a significant amount of salts from the surrounding rocks, which penetrate into the sea water.

Sodium chloride is the most common salt in seawater because it is the most soluble. Other substances dissolve less well, so there are not so many of them in the seas.

Special cases are calcium and silicon. Rivers bring large amounts of these two elements into the oceans, but despite this, they are scarce in seawater.

Calcium is “picked up” by various aquatic animals (corals, gastropods and bivalves) and built into their tanks or skeletons. Silicon, in turn, is used by microscopic algae to create cell walls.

The sun shining on the oceans causes large amounts of sea water to evaporate. However, the evaporated water leaves all the salt behind. This evaporation concentrates the salt in the sea, causing the water to become salty.

At the same time, some salt is deposited on the seabed, which maintains the balance of salinity in the water - otherwise, the sea would become saltier every year.

The salinity of water, or the salt content of water, varies depending on the location of the water resource. The least salty seas and oceans are near the north and south poles, where the sun does not shine as strongly and the water does not evaporate.

In addition, the salt water is diluted by melting glaciers.
In contrast, the sea near the equator evaporates more due to the elevated temperatures that prevail in this area.

This factor not only answers the question of why the sea is salty, but is also responsible for the increased density of water. This process is typical for some large lakes, which become saline during the process.

An example is where the water is so salty and dense that people can lie quietly on its surface.

The above factors are the causes of the salinity of sea water, as scientists understand them at the current level of scientific knowledge. However, there are several unresolved issues. It is not clear, for example, why different salts are found throughout the world in essentially the same proportions, although the salinity of individual seas varies significantly.

Are these hypotheses true?

Of course, no hypothesis is completely correct. Sea water has been formed over a very long time, so scientists have no reliable evidence about the reasons for its salinity. Why can all these hypotheses be refuted? Water washes away the land where there is no such high concentration of salt. During geological epochs, the salinity of water changed. The salt content also depends on the specific sea.

Water is different - salt water has different properties. Sea – characterized by a salinity of about 3.5% (1 kg of sea water contains 35 g of salt). Salt water has different densities and freezing points vary. The average density of sea water is 1.025 g/ml, and it freezes at a temperature of -2°C.

The question may sound different. How do we know that sea water is salty? The answer is simple - everyone can easily taste it. Therefore, everyone knows the fact of salinity, but the exact reason for this phenomenon remains a mystery.

Interesting fact! If you visit Sant Carles de la Rápita and go to the bay, you will see white mountains formed from salt extracted from sea water. If mining and trade in salt water are successful, then in the future, hypothetically, the sea risks becoming a “freshwater puddle”...

Double face of salt

There are huge reserves of salt on Earth, which can be extracted from the sea (sea salt) and from mines (rock salt).

It has been scientifically proven that table salt (sodium chloride) is a vital substance. Even without precise chemical and medical analyzes and research, it was clear to people from the very beginning that salt was a very valuable, useful and supportive substance that allowed both themselves and animals to survive in the world.

On the other hand, excessive salinity causes a decrease in soil fertility. It prevents plants from getting minerals into their roots. As a result of excessive soil salinity, for example in Australia, desertification is widespread.