Have you ever thought about this question? And meanwhile he long years provoked heated debate.
If you evaporate a liter of ocean water, then about 35 grams of salt will remain on the walls and at the bottom of the pan.
Is it a lot or a little - a teaspoon about a glass of water? The most incredulous can try ...
If we calculate how much salt is dissolved in the entire World Ocean, the numbers will turn out to be very impressive. It is enough to give such an example: if all the salt extracted from the ocean is spread evenly over the surface of the continents, archipelagos and even islands, then it will cover the land with a layer in which the Leningrad St. Isaac's Cathedral will hide!
But here's what's curious: every year, rivers carry about a billion tons of salts and about 400 million tons of silicates into the oceans, and meanwhile neither the salinity of ocean water nor its composition change noticeably. What's the matter here?
With silicates, it is more or less clear: they immediately precipitate. And what about salt?.. Apparently, particles of salt with splashes of waves of the smallest dust rise into the air and are picked up by air currents. Tiny crystals rise up and begin to play the role of nuclei for the condensation of atmospheric moisture. Water droplets form around them and form clouds. The wind drives the clouds away from the ocean, and there they rain down, returning the stolen salt to the earth's crust. And her journey with water to the ocean begins again. Here is the cycle...
And yet why is the ocean salty? Was it like this from the very beginning or did it gradually become salty? To answer these questions, scientists had to first solve the problem of the origin of the ocean in general. Did its hydrosphere form together with the Earth or later?
For a long time there was an opinion that the planets were initially in a molten state. It is clear that in this case there was no need to talk about any water on the surface. In this state of affairs, steam must have been rushing over the hot Earth, which from time to time would pour out hot rains and immediately evaporate again and gather into clouds and clouds. Only gradually, as the planet cooled, water from the atmosphere began to linger in the recesses and depressions of the relief. The first seas and oceans appeared. What could they be? Of course, fresh, if they originated from water from the atmosphere, from rain. And only then, after many years, the waters of the World Ocean became salty from the salt carried into the oceans by rivers from earth's crust. This rather harmonious picture existed for many years.
Today, however, everything has changed. First of all, today most scientists believe that the Earth, like the rest of the planets solar system, was formed from a cold gas and dust cloud. Blinded under the influence of gravity forces from huge blocks of ice and iron-stone flying in space. Then, gradually, the substance of this initial planetary coma began to delaminate. The young planet was warming up. The denser, heavier blocks sank deeper, closer to the center, and lighter substances, including water and gases, were pushed to the surface. Gases formed the primary atmosphere, and water formed the hydrosphere. Hot jets under high pressure made their way from the depths upward. On the way, they were saturated with mineral salts. And the water that escaped captivity to the surface of the young Earth probably looked more like a saturated brine, there were so many dissolved minerals in it. chemical elements. And this meant that from the very beginning, from its very birth, the ocean was already salty. It may not be the same as today, but that is still to come.
The idea of a deep, magmatic origin of ocean water was expressed by the Russian and Soviet scientist Vladimir Ivanovich Vernadsky back in the 1930s. Today, his point of view is supported by most experts around the world.
Academician A.P. Vinogradov believes that the ocean "survived" three stages of its development, starting from birth. The first of them fell on the time of the "lifeless" state of our planet. It was four to three billion years ago. There was no biosphere on Earth yet. The world ocean most likely was then small in volume and shallow. Volcanoes threw out from the bowels a lot of solutions, volatile smokes, which contained all kinds of acids. Rains from the sky poured hot and acrid. From such additives, the water in the ocean should have had a pronounced acid reaction.
True, this “acid stage” in the development of the ocean could not continue for a long time. Hot solutions escaping to the surface reacted with salts, bound metals and reduced both their own acidity and that of the primary ocean.
And then at some point in time, about three billion years ago, life began to form in the primordial "broth". At first the most primitive, then more and more complex.
The era of the formation of life lasted extremely long. Living organisms extracted carbon dioxide from the atmosphere and released free oxygen, which at first was practically absent in the primary atmosphere. Oxygen unrecognizably changed everything, even the main property of the atmosphere: it turned from a reducing atmosphere into an oxidizing one. Oxygen oxidized and precipitated, made less mobile such elements as iron and sulfur, calcium and magnesium, which were carried in the smoke of volcanoes above the Earth's surface. They settled and accumulated in the water. Boron and fluorine formed sparingly soluble salts, which also precipitated. The water in the ocean cooled, and silica ceased to dissolve in it. The smallest living organisms learned to use it to build their shells, which, after dying off, went into precipitation ...
Approximately six hundred million years ago, the composition of the water in the oceans and the composition of the atmosphere more or less stabilized. This is confirmed by the remains of extinct animals that paleontologists find in the deep layers of the earth.
I think it should be clear to you: the salinity of water is a very important characteristic of the oceans. And if it suddenly changes in some area, this is a signal: it means that surprises should be expected from Neptune here.
Samples of sea water are taken with the help of special devices - bathometers. Projectiles are simple. Ordinary hollow cylinder with two lids that can be easily locked. This process occurs semi-automatically with the help of a weight lowered from above when the bottles reach the required depth. This is done as follows: a garland with bottles tied to a long cable is lowered from the board of a research vessel into the water. At the same time, they make sure that each device paired with a thermometer is on its given horizon. Then you should wait a bit for the thermometers to come into thermal equilibrium with the surrounding water. And when the waiting time expires, a weight is thrown from above along the cable. A split weight with a hole in the middle slides, gets to the first bottle, releases its covers, which snap tightly into place. In addition, at the same time, the thermometers are overturned, fixing the measured temperature, and the second load is released - the second weight. She does the same operation with the second bottle, the third with the third, and so on until the very last device at depth. After that, the entire garland can be pulled up.
But the main thing begins in the laboratory, where the chlorine content of water is determined by rather complex chemical methods, and then it is recalculated for salinity. True, for last years engineers have designed instruments that measure salinity directly from the electrical conductivity of water. After all, the more salt in the water, the less resistance it has. electric current. There is even a special so-called STG probe (STG - salinity, temperature, depth), which shows a continuous depth distribution of all three of the most important parameters of ocean water.
Typically, ocean salinity fluctuates between 33 and 38 ppm. (1 ppm is equal to a tenth of a percent. And in order to make a solution with a saturation of 1 ppm, you need in a liter fresh water dissolve 1 gram of salt). But there are areas where salinity differs from the norm. There may be exits of underground rivers.
The ocean is the "kitchen of the weather"
What is "weather"? Some take this concept lightly. They say: “The weather? Yes, look out the window - this will be the weather. In fact, weather is the state of the atmosphere in this moment and in this place. If we consider the weather regime on average over many years, then this is the climate. The fact that it is important to be able to predict the weather and know how the climate will change does not need to be said much. This is clear to everyone. Improving methods for forecasting weather and other natural phenomena is an important national economic task. It is clear that the harvest depends on the weather, the construction work carried out by our country depends on the weather, and, finally, people's health depends on the weather.
You have the right to ask: “What does the ocean have to do with it if we live almost in the center of a huge continent?”
To answer this question, I will tell you about one interesting work of scientists.
For quite some time, forecasters have noticed that the average annual temperature in some parts of the North Atlantic fluctuates periodically. Now it rises by 1.5 and even 3 degrees, then it goes down. Experts have given these phenomena the names "warm sea" and "cold sea". At the same time, temperature deviations kept pace with changes atmospheric pressure. In the case of a “warm sea”, an anticyclone with increased pressure was established over Bermuda, while in the case of a “cold sea”, the pressure decreased in the same area. At the same time, the boundary between the warm Gulf Stream and the cold Labrador Current also changed.
But the most interesting thing was that exactly one month later the situation over Bermuda began to have a very definite effect in Scotland and Scandinavia, after 1.5 months - in Poland, after 2 months the weather changes reached the European part of our country. It turned out, as academician L. M. Brekhovskikh wrote: “If you want to know what the weather will be like in two months in the regions of the European part of the USSR, then carefully study what is happening in the North Atlantic off the coast of Iceland - what are the sea currents there, what is the heat reserve water, air temperature, etc. For an appropriate forecast for four months in advance, it is necessary to find out in the same detail what is being done in the Caribbean Sea.
For example, when the “cold sea” regime is established in January, it can be said with sufficient certainty that the February temperature in Switzerland will be three degrees below the norm. And this will certainly lead to an excessive consumption of electricity and fuel. When the “warm sea” regime is established in 2 months, we will also have protracted cyclones with rains and low pressure ...
So far, the mechanism of these connections is not entirely clear to scientists. Comprehensive studies of the ocean and atmosphere are just beginning. As early as the 1970s, meteorologists conceived the idea of implementing a large international program of GAAP - the Global atmospheric processes. For what? To make weather forecasts more accurate. At first, meteorologists wanted to manage on their own and even developed all the points of the program. But very little time passed, and it turned out that they could not do without oceanologists. And only when about 40 research vessels from different countries (including 13 Soviet ones) went to different parts of the World Ocean, when aircraft and artificial Earth weather satellites took an active part in this work, things went smoothly. It may seem strange to some why this ocean is so closely related to the atmosphere. Let's try to figure it out.
Heat balance of the planet
The main energy lever that controls the weather on Earth is heat! And where does our planet get it from? Scientists have calculated that more than 99.9 percent of all the energy that determines the state of the weather and the nature of the climate, as well as that that sets the ocean water in motion, comes from the Sun. Of course, some heat seeps from the bowels of the earth. But its share is very small. The energy received from space drives countless parts of the huge "heat engine" that is the Earth. And after use, it returns to space.
It would seem that we can conclude: the sun's rays, passing through the atmosphere, heat it, and give the rest of their heat to the ocean and land. But it's not right. Of all the energy that the atmosphere has, only 20 percent comes directly from heating by the sun's rays. Most of the rest of the energy is added to the atmosphere by the ocean. He, like a huge battery, stores it during the day, in hot summers, and releases it at night, softening cold winters not only in coastal areas, but also in the depths of continents.
How does the ocean regulate the heat balance of the planet? You know from the laws of physics that it takes 600 calories of heat to evaporate 1 gram of sea water. Water vapor condenses and collects into clouds. The winds drive the clouds to the high latitudes, where they rain down. The same physicists calculated that when steam condenses and 1 gram of moisture falls as rain, about 540 calories of heat are released. Well, compare ... It turns out that the lion's share of the energy stored in the tropics is transferred through the atmosphere to the poles with the help of evaporation alone. After all, an average layer of water more than a meter thick evaporates from the surface of the oceans per year. Those who love mathematics can also calculate the total number of calories of transferred heat. And then there are the currents...
In order to clearly imagine the interaction of the ocean with the atmosphere, scientists - oceanologists and meteorologists - must collect a lot of data. But at the same time, it must be borne in mind that the ocean lives, moves, and all its parameters are constantly changing. And there is nothing to say about the mobility of the atmosphere.
In the Soviet Union, under the leadership of Academician G. I. Marchuk, a method of mathematical models of the circulation of the atmosphere and ocean was developed. What is a "mathematical model"? In principle, this is a system of equations that describe certain interrelated processes in complex systems. For oceanologists, such a system is the ocean, for meteorologists it is the Earth's atmosphere, the ocean of air. Solve these equations with the help of electronic computers.
Mathematical models are an extremely successful invention of the human mind. With their help, on paper, you can create analogues of a variety of conditions. Think, suppose, people block the straits of the sea with dams. And ocean currents follow them. What will the planned event turn out for the whole Earth? And this question can be answered mathematical models. For mathematicians, there are problems of local significance, and there are also global ones. Here is a relatively recent problem, for example. The developing industry every year increases the amount of carbon dioxide that is emitted into the atmosphere. It would seem that nothing special: carbon dioxide is a transparent substance, it does not delay the sun's rays; in addition, it serves to nourish plants ... But it turns out that carbon dioxide has an insidious property: it passes light rays, but it delays heat rays. It turns out that solar radiation to the surface of the Earth passes unhindered, and the heat from the heated water and land does not go back into space. How greenhouse glass covers our planet with carbon dioxide. This means that the surface temperature also increases.
You might be thinking, “Well, what’s wrong with that? Let there be more heat, they will grow in Moscow, Leningrad, or maybe even in Murmansk palm trees will grow ... ”In fact, warming will turn into innumerable troubles for us. The ice and eternal snows will begin to melt. Additional water will pour into the world's oceans, raise its level, flood coastal cities. If the polar ice caps melted, the level of the world's oceans would rise by about 60 meters!
But is such a global catastrophe? To accurately answer this question, you need to make mathematical models very carefully. To take into account in them not only the current achievements of science, but also to program forecasts for the future. So far, we can only say that the heat balance of our planet is not very stable. Traces of past epochs show that the climate of the Earth in the past experienced very significant fluctuations. During the existence of man, there have been several such fluctuations. Scientists call them cycles of glaciation. During each such cycle, the Earth passed from the state of interglacial to the state of glaciation and vice versa. Unfortunately, the glacial phases each time lasted much longer than the interglacials.
During periods of glaciation, mountain glaciers sea ice and the ice sheets grew considerably in size. Water was frozen out of the ocean, and its level dropped. For example, during the last great glaciation, the maximum of which was only eighteen thousand years ago, the level of the World Ocean dropped by more than 100 meters, exposing most of the shelf.
But not only great ice ages threaten the Earth. They are still quite rare. But even during interglacial periods, there are so-called small ice ages on our planet. So, having collected a lot of ship observations and carefully selecting all references to the weather of past years from ancient annals and chronicles, scientists found that from about 1450 to 1850, winters on Earth were much more severe than in our time. The summers were shorter and not as hot, and the mountain glaciers descended well below their current limits. Sailors noted that the ice edge in the Atlantic passed much further south.
Why? What is the reason for such a cataclysm? Science cannot yet answer this question. Imagine how much work remains to be done in this area!
How many discoveries await future oceanologists and meteorologists! The prospects for them are truly remarkable.
Where is born "tai fyn" - "big wind" and where is "khurakan" - "heart of the sky" and "heart of the earth"
Of particular interest to all people is the question of how changing conditions in the ocean affect the occurrence of terrible tropical cyclones, which are called hurricanes in the Atlantic, and typhoons in the Indian and Pacific oceans.
Today, thanks to the space service of meteorological satellites and direct observations of astronauts, the areas of origin of tropical cyclones are well known. There are not very many of them: in the Atlantic it is mainly the Caribbean Sea and the Gulf of Mexico; in the Indian and Pacific Oceans, autumn typhoons originate in the southern and southwestern regions.
In addition, their centers are the Philippine Islands and the South China Sea. But typhoons that hit the east coast of Asia and India all year round originate in the western part of Pacific Ocean and in the northern regions of the Indian.
A tropical cyclone is a system of very strong winds that blow and swirl around a windless center of low pressure called the eye of the cyclone. It is interesting that in the Northern Hemisphere the wind spins around the "eye of the cyclone" always counterclockwise, and in the Southern Hemisphere - along its course. A cyclone can capture an area of up to 1,000 square kilometers, while its windless "eye" will only have a diameter of some 20-40 kilometers. The wind on the periphery of the cyclone can pick up speed up to 300 kilometers per hour.
Tropical cyclones cause enormous damage both at sea and on land in coastal areas. They generate giant waves and sink ships. Water breaks into the flat coast, destroys shallows, causes terrible floods and destroys people's homes.
In September 1900, in North America, in the state of Texas, about 6,000 people died during a hurricane. In September 1928, a tropical cyclone swept over the state of Florida, claiming about 2,000 lives. And ten years later, about the same hurricane killed 600 New Englanders. The enumeration of the sad consequences could go on and on. But you have probably already noticed that the closer to our days, the less number victims. This is because weather forecasters have already learned to warn of a formidable phenomenon at least a day in advance.
Moving over land or over water with a colder surface than in the places of their birth, hurricanes lose their strength. So it is the evaporation warm water energizes them. And I must say, it feeds well. The total energy of a tropical cyclone is roughly the energy of hundreds of 20-megaton bombs detonating simultaneously! It is comparable to the entire amount of electricity that our country's power plants generate over a five-year period.
Traditionally, tropical cyclones are given female names. Previously, they were called the names of those saints on whose feast day they appeared. In addition, they were also assigned a number. It got pretty cumbersome. During the Second World War, when information about an approaching storm had to be transmitted by radio, preferably as quickly as possible, letters of the Latin alphabet began to be assigned to tropical cyclones. And in order to transmit a letter without error, radio operators used the appropriate female name starting with this letter. And so the tradition was born. However, since 1979, the US weather service has added male names to the list of cyclones.
"Huracan" in the language of the Indians of Guatemala means "one-legged." So they called it fast, like the wind, the creator and ruler of the world, the lord of thunderstorms, winds and hurricanes. The most common epithets of this terrible deity were "the heart of heaven" and "the heart of the earth."
But the word "typhoon" comes from the Chinese words "tai feng" - "big wind". And you can judge how true this is.
Why is ocean water salty and fresh water in rivers? The answer to this question is ambiguous. There are different points of view that reveal the essence of the problem. According to scientists, it all comes down to the ability of water to break down rock and leach easily soluble components out of it, which end up in the ocean. This process is ongoing. Salts saturate sea water, giving it a bitter-salty taste.
Everything seems to be clear, but at the same time, according to this issue There are two diametrically opposed opinions. The first boils down to the fact that all the salts dissolved in water are carried by rivers into the ocean, saturating sea water. There are 70 times less salts in river water, therefore it is impossible to determine their presence in it without special analyzes. We think that river water is fresh. In fact, this is not entirely true. Saturation of sea water with salts occurs constantly. This is facilitated by the evaporation process, as a result of which the amount of salts is constantly increasing. This process is endless, and lasts about two billion years. There is enough time to make the water salty.
The composition of sea water is quite complex. It contains almost the entire periodic table. But most of all, it contains sodium chloride, which makes it salty. By the way, in closed lakes the water is also salty, which confirms the correctness of this hypothesis.
Everything seems to be correct, but there is one but! Sea water contains salts of hydrochloric acid, and river water contains coal. That is why scientists put forward an alternative hypothesis. They believe that sea water was originally salty, and rivers have nothing to do with it. This is due to volcanic activity, the peak of which occurred at the time of the formation of the earth's crust. Volcanoes emitted huge amounts of steam saturated with acids into the atmosphere, which condensed and fell to the ground in the form of acid rain. Sediments saturated seawater with acid, which reacted with solid basaltic rocks. As a result, a huge amount of alkali was released, including sodium, potassium and calcium. The salt thus obtained neutralized the acid in the sea water.
Over time, volcanic activity decreased, the atmosphere was cleared of vapors, and less and less acid rain fell. About 500 million years ago, the composition of sea water stabilized and became what we know it today. But the carbonates that enter the ocean with river water serve as an ideal building material for marine organisms. They build coral islands, shells, their skeletons out of it.
Which hypothesis to prefer is a purely personal matter. In our opinion, they both have a right to exist.
If you've ever surfed or swum, you're probably familiar with one of the ocean's strongest qualities: its salinity. The oceans usually 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 acidic 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 - it is they who 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 annually they dump into the ocean approximately 225 million tons of dissolved solids. But rivers are not the only source 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 negative side: 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 carried by rivers to the oceans in in large numbers. 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. Water in the sea and ocean formed over millions of years, so scientists do not have reliable evidence 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.
Say, rivers wash it into the waters of the oceans from the soil? Nothing like this. Not much water from rivers enters the oceans. Free fresh water on Earth is less than 1%. And even less enters the seas and oceans, so that the supply waters cannot “desalinate” or “salt” the ocean.
Why is the water in the oceans salty?
Actually, sea water contains more than just salt. If you extract all the gold dissolved there from the oceans, you can cover the entire Earth a golden layer one and a half meters thick!
In addition, sea water contains iron, magnesium, calcium, iodine, sulfur ... How did all this get there?
Four and a half billion years ago, literally the entire surface of the planet was strewn with numerous active volcanoes. Trillions of tons of molten lava poured onto the surface, and volcanic gases were ejected into the atmosphere in huge quantities.
Volcanic gases contain a lot of carbon dioxide, sulfur oxide, sulfuric and hydrochloric acids, methane and many other substances from the bowels of the Earth. Therefore, the atmosphere of our planet was opaque, red-hot and poisonous.
As time went on, however, the primordial atmosphere began to cool. When it cooled down to +100 degrees, water vapor turned into drops of water that began to fall to the surface. The first rain fell on planet Earth - what a rain!
First, this rain has been pouring non-stop for hundreds of millions of years. Secondly, it was warm, even hot, and very cloudy. Thirdly, the drops of this rain contained an incredible amount of burning acids - sulfuric and hydrochloric. It’s not fun to run and jump in such a rain in panties - you need a spacesuit here!
Puddles of water began to form on the surface of the Earth, which gradually grew, turning first into large puddles, then into lakes, then into seas, then into oceans ... At some point, our planet was completely covered with one huge ocean, on it practically there was no sushi! Only tiny volcanic islands. It would be more correct to call such a planet not Earth, but Water - all of it was one vast (but not very deep) ocean.
What was the water of this primordial ocean like?
Lake Kawah in Java
On the island of Java, in Indonesia, there is an active volcano Ijen. Inside its crater is the amazing Lake Kavakh, the waters of which are somewhat similar to the ancient lakes and seas of the Earth. Do not even try to lie on the local beach, let alone swim in this lake! Instead of sand, its shores are densely strewn with sulfur, and water burns the skin like fire - if it gets into your eyes, you can even go blind!
The water of Lake Kavakh is a very strong mixture of sulfuric and hydrochloric acid. Almost as caustic and aggressive as the acid inside a car battery, only natural. Imagine - if you lower an iron nail into such water, it will hiss, gas bubbles will come from it, and after a while the nail will completely dissolve in this water, like a lump of sugar in a glass of hot tea! If we decide to swim on this lake in a boat made of metal, in a few hours the hull of the boat will corrode with acid, and it will sink along with the passengers! Why is this happening?
The fact is that this is one of the main properties of the acid - when it "meets" with metals, it immediately enters into a storm with them. chemical reaction. In this reaction, hydrogen gas and a substance are formed from metal and acid, which chemists call ... salt!
For example, in our experience with a nail in the water of Lake Kavakh hydrochloric acid reacts with the iron from which the nail is made. The result is hydrogen (remember the sizzling bubbles?) and a salt called ferric chloride. In exactly the same way, in the waters of the ancient ocean of the Earth, hydrochloric acid reacted with destroyed rocks, including sodium metal - and sodium chloride was obtained, that is, kitchen salt familiar to all of us ...
As a result, ocean water from muddy, burning and acidic gradually turned into transparent, salty and not at all dangerous for humans - swimming in sea water is not only not harmful, but even very healthy!
This transformation was completed a very long time ago - scientists say that already two billion years ago chemical composition The world ocean practically did not differ from the modern one.
So wash out minerals from the soil on the salinity of the water of the oceans is not particularly affected ...
How much horsepower is in a horse? What ties up the Order of the Garter? What were the real names of Athos, Porthos and Aramis? How potatoes are prepared in her homeland - in South America? Subscribe to our magazine and read!
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