The phenomena of the world around us raise a lot of questions among the curious. For example, when you find yourself on the shore of an endless reservoir, you begin to wonder: what kind of water in the ocean is fresh or salty? How can you explain the chemical composition of ocean water and is it drinkable?

The composition of water in the seas and oceans has been surprising people since ancient times. In Germany, there are legends that claim that there is a magical salt mill at the bottom of every sea, and in Hungary - that this is all because of the tears of an unfortunate girl grieving under the water column.

Finding out if the ocean is salty is actually as easy as shelling pears - just turn to the materials of modern research. Indeed, sea and ocean water is very salty, and sometimes the concentration of salts is excessively high: one glass of a “drink” from the Dead Sea is enough to not regain consciousness at all.

The most saline expanses of water in the world are:

• Atlantic Ocean: southern part (salt concentration is 37.9 ppm) and northern part (37.6);
• Pacific Ocean: southern (36.9) and northern (35.9);
• The entire Indian Ocean (36.4 ppm).

Why is ocean water salty

Oddly enough, but to such a simple question - why is the water in the ocean salty - even modern scientists have not found a definite answer. Some researchers believe that this is due to volcanic activity, while others believe that salt enters the oceans through rivers and seas.

About the amount of salt and fresh water on earth.

Two theories

The first group of scientists claims that a very long time ago, when the earth's crust was just being formed, volcanoes on Earth were extremely active. Their eruptions led to the occurrence of acid rain - but the oceans themselves consisted of acids. As a result, various complex substances "collided" with each other, and as a result of the reaction, the ocean waters became safe for life, which had yet to be born. But very salty.

As for the "earthen" theory, it says that salts are contained in all water bodies of the world. And this is true - fresh water is not devoid of salts, there are just very few of them. Flowing into the oceans, rivers and seas bring with them salt washed out of the soil. They, in turn, remain in place - and where else can they go? Yes, during the natural cycle, water also evaporates from the surface of the oceans, but salts are too heavy to go after it.

As you can see for yourself, these theories are quite logical. Or maybe both groups of researchers are right at once, and at first salts arose thanks to volcanoes, and numerous currents brought them even more?

Can a fresh ocean arise

What determines the salinity of ocean water? Many factors play a role here, including underwater currents, the presence of glaciers, the intensity of their melting, the activity of evaporation, etc. In addition, in the depths, under the very bottom of the ocean, there are deposits of the purest fresh water.

But even if we imagine that a crystal-clear body of water appears on Earth, it is obvious that fresh water in the ocean would not linger for a long time. After all, no one doubts that rivers constantly add salt washed out of the soil to ocean waters - scientists are skeptical only that this could cause the appearance of vast salt reservoirs as such.

Can you drink sea water

So, we figured out why the water in the seas and oceans is salty, and found out that drinking it is not recommended. But why is there such a limitation?

In fact, ocean water is contraindicated for humans due to the structural features of the body. The kidneys are responsible for removing salts and other “heavy” substances from food, which may simply not be able to cope with the excess load. A liter of sea water contains more than 30 grams of salt! That is why the unfortunate, shipwrecked and managed to escape in boats, often die of thirst in the middle of the water.

Why is the sea salty: Video

Not only children, but also adults often think about why the water in the ocean and the sea is salty. It must be fresh, because it is replenished by rains, rivers, melting glaciers. When mixing fresh and salty liquid in equal volume, it will remain salty. The same thing happens with the ocean. No matter how much liquid enters it, it still will not become insipid. Everyone needs to know about the salt content, since even in a marine aquarium, water parameters play an important role.

Where is the saltiest water

Even from the school geography course, many people remember why the water is salty in the seas and which one comes first. We are talking about the Dead Sea, but this is not entirely true. The Dead Sea is 10 times saltier than the ocean average (about 340 grams per 1 liter, a formula is used to calculate the specific gravity of sea water), there are several reasons for this: strong evaporation, rare rains and only one Jordan River flowing into it. In such a liquid, no one can survive, except for a few types of bacteria. It is safe for a person to swim in the Dead Sea or use the mud for healing. Surely everyone knows about an interesting fact: it is impossible to drown in it because of the high concentration of salts. Sea water seems to push the body of a person, no matter how hard he tries to sink to the bottom.

The second place in terms of salinity is occupied by the Red Sea - 41 grams of salt per liter. It was formed approximately 25 million years ago due to the movement of glaciers. Sea water is always warm (even in the winter season), has a rich wildlife.

The Mediterranean completes the top three salty seas. It contains 39.5 grams of salt per liter of liquid, sea water has a boiling point of 100 degrees. It is one of the warmest seas in the World Ocean: in summer the temperature reaches 25 degrees, and in winter - 12. Unlike the Dead Sea, there are enough inhabitants here: sharks, rays, sea turtles, mussels and more than five hundred species of fish. The seas with a high salt concentration include the White, Barents, Chukchi, and Japanese seas. In them, sea waters contain from 30 to 38% salt.

The saltiest place on Earth is Lake Don Juan, located in the northeast of Antarctica. It has a shallow depth (up to 15 cm), sometimes it is compared to a puddle. At the same time, it has such a high concentration of salts that the liquid does not freeze even at an air temperature of -50 degrees. The water in Lake Don Juan is 2 times saltier than the Dead Sea and 18 times the ocean waters.

Don Juan was discovered by chance in 61 of the last century. United States Navy helicopter pilots made the first expedition to explore a seawater lake. One of the pilots was named Donald Rowe, the other was John Hick, and the saltiest body of water, Don Juan (in Spanish), was named after them.

The Antarctic Dry Valleys are characterized by severe cold and winds. Water appeared from underground, and salt is the result of the evaporation of the upper layers. There are practically no living organisms in it (with the exception of fungi, yeast, algae), in such sea water the microflora has adapted. It is believed that if water is ever found on Mars, it will be the same as in this lake.

Why is ocean water salty

At school, everyone studied geography, in the lessons of which the teacher told why sea water is salty. However, many questions arise. For example, why are precipitation, condensate, rivers, springs, melting glaciers fresh, but the sea does not become less salty? River water is not entirely fresh, as there are salts in the soil. The liquid slowly washes them away, bringing them into the world's oceans. Of course, the person does not notice this at all. Primitive oceans were fresh, and over time they were filled with salty rivers. Research led to other results - the rivers could not salt all the water.

According to the first theory, sea water with a high salt content was the result of massive volcanic eruptions many millions of years ago. They were extremely active and resulted in constant acid rain. The oceans were composed of 10% mixture of methane, chlorine and sulfur, 15% carbon dioxide and 75% water, which is the answer to the question "What substance is found most in sea water?". Numerous acid rains led to reactions, and as a result, this became the cause of the concentrated salt solution.

It is noteworthy that gold can be mined from sea water. A liter of liquid usually contains up to several billionths of a gram of gold. One of the springs is located on the Reykjanes peninsula.

The second theory has already been described above, from which it follows: salt is contained in absolutely every body of water on Earth. Studies show that this is true, but the concentration is negligible for a person to notice. Rivers flowing into the oceans bring washed salts from the soil daily.

Many people believe that the water that evaporates from the surface of the sea or ocean is also salty. However, only moisture is subject to vaporization. A simple experiment can be done at home by leaving an aquarium without fish with sea water near a heat source. After a while, the liquid will evaporate, and the salt will remain.

During the electrolysis of sea water, salt ions accumulate on the corresponding electrodes. Scientists are improving this process by developing safe coatings for the anode.

It cannot be said that either of the two theories is wrong. Both of them are quite logical, but scientists still cannot confirm or refute them.

Can a fresh ocean arise

To answer the question "Can the ocean become fresh?", it is necessary to understand what influences this. The properties of sea waters depend on many factors, only some of them:

• underwater currents;
• evaporation and their activity;
• features of the movement of sea water;
• the presence of glaciers, as well as the rate of melting.

At the depth of the ocean there are deposits of clean fresh water, but not everyone knows that there is gold in sea water. Salt waters cannot become fresh even after many centuries. Scientists are confident that evaporating water does not change salinity. The salt level always remains at the same level. The constancy of the salt composition was discovered by Dietmar, after whom the law is named.

If this does happen (theoretically), it will entail irreversible consequences for the entire planet. First of all, many living organisms will die, because even people use isotonic solutions of sea water. For a long time, fresh liquid will not remain, since salts constantly flow from rivers into ocean waters. However, the latter is just one of several theories as to why sea water is highly saline.

Can the ocean become fresh? Why is sea water salty? These questions are asked not only by curious children, but also by many adults. Everyone knows that there is salt water in the sea and ocean, but even scientists do not explain why this happens. There are several theories, but which one is correct is still not clear. There is no confirmation whether waters with sea salt can evaporate.

If you've ever surfed or swum, you're probably familiar with one of the ocean's strongest qualities: its salinity. The oceans tend to contain more salt than most seas on the planet. On average, the concentration of salt in the ocean fluctuates around 35 grams per 1 liter of sea water, with fluctuations from 3.4 to 3.6% (34-36 ‰). But if you don’t surprise anyone with the salinity of the ocean, then here’s the question of why exactly it is so salty, m legs can be confusing. Let's see why the sea water in the ocean is so salty?

If you were to remove all the salt from the oceans and distribute it over the entire surface of the Earth, it would form a layer about 150 meters thick. This is more than the height of the two Spassky Towers on Red Square in Moscow, installed on top of each other. But how did so much salt get into the oceans?

You can thank the stones on the shore for this.

Rainwater contains a certain amount of dissolved carbon dioxide from the atmosphere. Mildly acid rain breaks down rocks on land, causing dissolved minerals and ions, including chloride and sodium, to enter the ocean through hands and streams. It is worth noting that, for the most part, dissolved ions are responsible for the salinity of the ocean - they make 90% of their contribution to the salinity of the oceans.

Notably, rivers around the world also have salt, but the water in them generally does not taste salty like the water in the ocean. This is because the ocean acts as a repository for all these minerals. Their concentration is higher there than in the sea. Rivers play an important role in transporting salts and other minerals to the ocean, and according to NOAA they release an estimated 225 million tons of dissolved solids into the ocean every year. But rivers are not the only source of salt in the ocean.

Salt can also enter the oceans through hydrothermal vents. These holes release dissolved minerals into the sea. As seawater seeps into the rocks at the seafloor and closer to the Earth's core, it begins to heat up. It then returns to the surface, where it flows from hydrothermal vents.

In areas of underwater volcanism, salt can also enter the ocean. When fresh lava emerges from volcanoes on the seafloor, it reacts with salty seawater, which dissolves some of the minerals found in the lava.

But the ocean is not always equally salty. Some parts of the oceans are saltier than others. For example, the seafloor of the Gulf of Mexico is filled with saline pools, caused by the dissolution of ancient layers of salt into the seafloor. These pools of super-salt sludge may even harbor strange bacteria at the bottom that scientists believe could be found elsewhere.

Water occupies most of the Earth's territory. The vast majority of water is in the oceans and seas, and it is salty. According to the Ocean Service, more than 3% sodium chloride (common salt) is found in ocean water.

Why is the water in the seas and oceans salty and where does this salt come from? With the answer to this question, we will try to understand the article.

General information

It happened that the sailors of ships lost in sea waters or wrecked died of thirst, although there was a lot of water around. Few people know that sea water has a composition that is not suitable for the human body. It has a specific bitter-salty taste, which is given by salts dissolved in water.

Rivers flowing into the seas have fresh water, in which the concentration of dissolved salts is much lower than in the sea. But how is this possible, why is the water in the sea salty, and fresh in the river?

For 4 billion years, the continents have been watered by rain. Water, penetrating the rocks, finds its way to the sea. She carries with her dissolved salt into it. In the course of a long geological history, the amount of salt gradually increases. This is one of the simplest hypotheses.

A little about the benefits and harms of salt

Before we find out why the sea is salty and the river is not, let's decide whether salt is useful or harmful. As it turned out, there are huge reserves of salt on Earth, both in the seas (sea) and in the bowels of the earth (stone). Sodium chloride has been scientifically proven to be a vital substance. It has long been known to people that salt is a rather useful and valuable substance that is necessary for both people and animals.

However, there is also a negative side: an excessive amount of salt in the soil leads to a decrease in its fertility. As a result, desertification of territories occurs (for example, in Australia).

Why is the sea water salty

Part of the salt enters the water from the seabed, which contains stones containing salt, from which salt enters the water. Sodium chloride can also come from volcanic valves. But to a greater extent, salts come from the continents. One kilogram of sea water contains, on average, up to 35 grams of salt, and most of it (about 85%) is sodium chloride (kitchen salt known to everyone).

Sources of salt in the sea:

• Weathering of rocks: when rocks get wet, substances are washed out of them, and salts are carried away to the seas (a similar effect occurs with rocks on the seabed).
• Explosions of underwater volcanoes: they release lava into the water, which reacts with sea water and dissolves certain substances in it.

Water has the ability to penetrate into cracks that lie deep in the ocean in the zones of mid-ocean ridges. The stones are hot there (there is often lava at the bottom). Water, heating up in cracks, dissolves a large amount of salts from underwater rocks that enter the sea water.

Why is sea water salty? Because sodium chloride is the most common salt in it due to the fact that it is it that dissolves best of all substances. However, silicon and calcium are also brought by rivers to the oceans in large quantities. At the same time, there are not so many of them in sea water. This is due to the fact that calcium is “picked up” by various aquatic animals (corals, gastropods and bivalves), and silicon is used by microscopic algae (cell walls are created).

The sun causes the evaporation of a huge amount of water in the seas and oceans. From the evaporated water, salt remains, concentrating in the sea. Therefore, the water becomes salty. It should be noted that some salt is deposited on the seabed. Thanks to this, the balance of salt concentration in the water is maintained, otherwise the sea would become even more salty.

Are the versions correct?

Where does the salt in the sea come from? Which of the hypotheses is the most correct? None of the versions can be ranked as the most correct. The water in the sea and ocean formed over millions of years, so scientists do not have reliable evidence of its salinity. It is known that water washes out the mainland, which does not contain as much salt. The salinity of water has changed in different geological epochs. And each sea has a different concentration of salt and different properties. The density of water is different, there are differences in freezing points.

It turns out that everyone knows the fact of salinity, but the exact cause of this phenomenon remains a mystery.

Some factors affecting the concentration of salt in water

Answering the question why the water in the sea is salty, one should also find out why the concentration of salt in different seas is different. The salinity of the water varies depending on the location of the natural reservoir. The least saline oceans and seas are located closer to the north and south poles, where the sun does not shine much, and therefore the water does not evaporate. In addition, the water is diluted with the waters of melted glaciers.

The waters of the seas near the equator evaporate more due to elevated temperatures. This factor also affects the increased density of water in these places. Such a process can also occur on some large lakes, which also turn into salty ones. An example is the Dead Sea, where the density and salinity of the water allows people to lie quietly on its surface.

The temperature of the water in the sea also affects the concentration of salt. An example is the Baltic Sea. Due to low water temperatures, it contains 8 times less salt than, for example, in the Persian Gulf.

Finally

The above hypotheses of the causes of water salinity in the seas and oceans are the opinion of scientists at the current level of knowledge.

One fact is interesting. If water evaporated from all the oceans and seas on Earth today, the remaining salt would form a layer up to 75 meters high all over the world.