Ebbs and flows in the seas and in the universe. Tide - what is it? What causes high and low tides Sea high and low tide periods
The water surface level in the seas and oceans of our planet changes periodically and fluctuates in certain intervals. These periodic oscillations are sea tides.
Picture of sea tides
To visualize picture of sea ebbs and flows, imagine that you are standing on the sloping shore of the ocean, in some bay, 200–300 meters from the water. There are many different objects on the sand - an old anchor, a little closer a large pile of white stone. Now, not far away, lies the iron hull of a small boat that has fallen on its side. The bottom of its hull in the bow is badly damaged. Obviously, once this ship, being not far from the shore, hit an anchor. This accident occurred, in all likelihood, during low tide, and, apparently, the ship had been lying in this place for many years, since almost its entire hull had become covered with brown rust. You are inclined to consider the careless captain to be the culprit of the ship's accident. Apparently, the anchor was the sharp weapon that the ship that had fallen on its side struck. You are looking for this anchor and cannot find it. Where could he have gone? Then you notice that the water is already approaching a pile of white stones, and then you realize that the anchor you saw has long been flooded by a tidal wave. The water “steps” onto the shore, it continues to rise further and further upward. Now the pile of white stones turned out to be almost all hidden under water.Phenomena of sea tides
Phenomena of sea tides people have long been associated with the movement of the Moon, but this connection remained a mystery until the brilliant mathematician Isaac Newton did not explain on the basis of the law of gravity he discovered. The cause of these phenomena is the effect of the Moon’s gravity on the Earth’s water shell. Still famous Galileo Galilei connected the ebb and flow of the tides with the rotation of the Earth and saw in this one of the most substantiated and true proofs of the validity of the teachings of Nicolaus Copernicus (more details:). The Paris Academy of Sciences in 1738 announced a prize to the one who would give the most substantiated presentation of the theory of tides. The award was then received Euler, Maclaurin, D. Bernoulli and Cavalieri. The first three took Newton's law of gravitation as the basis for their work, and the Jesuit Cavalieri explained tides based on Descartes' vortex hypothesis. However, the most outstanding works in this area belong to Newton and Laplace, and all subsequent research is based on the findings of these great scientists.How to explain the phenomenon of ebb and flow
How most clearly explain the phenomenon of ebb and flow. If, for simplicity, we assume that the earth's surface is completely covered with water, and we look at the globe from one of its poles, then the picture of sea ebbs and flows can be presented as follows.Lunar attraction
That part of the surface of our planet that faces the Moon is closest to it; as a result, it is exposed to greater force lunar gravity, than, for example, the central part of our planet and, therefore, is pulled towards the Moon more than the rest of the Earth. Because of this, a tidal hump is formed on the side facing the Moon. At the same time, on the opposite side of the Earth, which is least subject to the gravity of the Moon, the same tidal hump appears. The Earth therefore takes the form of a figure somewhat elongated along a straight line connecting the centers of our planet and the Moon. Thus, on two opposite sides of the Earth, located on the same straight line, which passes through the centers of the Earth and the Moon, two large humps are formed, two huge water swellings. At the same time, on the other two sides of our planet, located at an angle of ninety degrees from the above points of maximum tide, the greatest low tides occur. Here the water drops more than anywhere else on the surface of the globe. The line connecting these points at low tide shortens somewhat, and thus creates the impression of an increase in the elongation of the Earth in the direction of the maximum high tide points. Due to lunar gravity, these points of maximum tide constantly maintain their position relative to the Moon, but since the Earth rotates around its axis, during the day they seem to move across the entire surface of the globe. That's why in each area there are two high and two low tides during the day.Solar ebbs and flows
The Sun, like the Moon, produces ebbs and flows by the force of its gravity. But it is located at a much greater distance from our planet compared to the Moon, and the solar tides that occur on Earth are almost two and a half times less than the lunar ones. That's why solar tides, are not observed separately, but only their influence on the magnitude of lunar tides is considered. So, for example, The highest sea tides occur during full and new moons, since at this time the Earth, Moon and Sun are on the same straight line, and our daylight increases the attraction of the Moon with its attraction. On the contrary, when we observe the Moon in the first or last quarter (phase), there are lowest sea tides. This is explained by the fact that in this case the lunar tide coincides with solar ebb. The effect of lunar gravity is reduced by the amount of gravity of the Sun.Tidal friction
« Tidal friction", existing on our planet, in turn affects the lunar orbit, since the tidal wave caused by lunar gravity has a reverse effect on the Moon, creating a tendency to accelerate its movement. As a result, the Moon gradually moves away from the Earth, its period of revolution increases, and it, in all likelihood, lags a little behind in its movement.The magnitude of sea tides
In addition to the relative position in space of the Sun, Earth and Moon, on the magnitude of the sea tides In each individual area, the shape of the seabed and the nature of the shoreline influence. It is also known that in closed seas, such as the Aral, Caspian, Azov and Black seas, ebbs and flows are almost never observed. It is difficult to detect them in the open oceans; here the tides barely reach one meter, the water level rises very little. But in some bays there are tides of such colossal magnitude that the water rises to a height of more than ten meters and in some places floods colossal spaces.
Ebbs and flows in the air and solid shells of the Earth
Ebbs and flows also happen in the air and solid shells of the Earth. We hardly notice these phenomena in the lower layers of the atmosphere. For comparison, we point out that ebbs and flows are not observed at the bottom of the oceans. This circumstance is explained by the fact that mainly the upper layers of the water shell are involved in tidal processes. Ebbs and flows in the air envelope can only be detected by very long-term observation of changes in atmospheric pressure. As for the earth’s crust, each part of it, due to the tidal action of the Moon, rises twice during the day and falls twice by about several decimeters. In other words, fluctuations in the solid shell of our planet are approximately three times smaller in magnitude than fluctuations in the surface level of the oceans. Thus, our planet seems to be breathing all the time, taking deep breaths and exhalations, and its outer shell, like the chest of a great miracle hero, either rises or falls a little. These processes occurring in the solid shell of the Earth can only be detected with the help of instruments used to record earthquakes. It should be noted that ebbs and flows occur on other world bodies and have a huge impact on their development. If the Moon were motionless in relation to the Earth, then in the absence of other factors influencing the delay of the tidal wave, two high tides and two low tides would occur every 6 hours in any place on the globe every 6 hours. But since the Moon continuously revolves around the Earth and, moreover, in the same direction in which our planet rotates around its axis, there is some delay: the Earth manages to turn towards the Moon with each part not within 24 hours, but in approximately 24 hours and 50 minutes. Therefore, in each area, the ebb or flow of the tide does not last exactly 6 hours, but about 6 hours and 12.5 minutes.Alternating tides
Moreover, it should be noted that the correctness alternating tides is violated depending on the nature of the location of the continents on our planet and the continuous friction of water on the surface of the Earth. These irregularities in alternation sometimes reach several hours. Thus, the “highest” water occurs not at the moment of the culmination of the Moon, as it should be according to theory, but several hours later than the passage of the Moon through the meridian; this delay is called the port applied clock and sometimes reaches 12 hours. Previously, it was widely believed that the ebb and flow of sea tides were related to sea currents. Now everyone knows that these are phenomena of a different order. A tide is a type of wave movement, similar to that caused by wind. When a tidal wave approaches, a floating object oscillates, as with a wave arising from the wind - forward and backward, down and up, but is not carried away by it, like a current. The period of a tidal wave is about 12 hours and 25 minutes, and after this period of time the object usually returns to its original position. The force that causes tides is many times less than the force of gravity. While the force of gravity is inversely proportional to the square of the distance between the attracting bodies, the force causing tides is approximately is inversely proportional to the cube of this distance, and not at all its square.The world's oceans live according to their own rules, which are harmoniously combined with the laws of the universe. For a long time, people noticed that they were actively moving, but could not understand what was causing these fluctuations in sea level. Let's find out what the ebb and flow is?
Ebbs and flows: mysteries of the ocean
The sailors knew very well that the ebb and flow of tides is a daily phenomenon. But neither ordinary residents nor scientific minds could understand the nature of these changes. As early as the fifth century BC, philosophers tried to describe and characterize how the World Ocean moved. seemed something fantastic and extraordinary. Even reputable scientists considered the tides to be the breathing of the planet. This version has existed for several millennia. It was only at the end of the seventeenth century that the meaning of the word "tide" was associated with the movement of the Moon. But it was never possible to explain this process from a scientific point of view. Hundreds of years later, scientists figured out this mystery and gave an accurate definition of the daily change in water levels. The science of oceanology, which emerged in the twentieth century, established that the tide is the rise and fall of the water level of the World Ocean due to the gravitational influence of the Moon.
Are the tides the same everywhere?
The influence of the Moon on the earth's crust is not the same, so it cannot be said that the tides are identical all over the world. In some parts of the planet, daily sea level changes reach sixteen meters. And residents of the Black Sea coast practically do not notice the ebbs and flows at all, since they are the most insignificant in the world.
Usually the change occurs twice a day - in the morning and in the evening. But in the South China Sea, the tide is a movement of water masses that occurs only once in twenty-four hours. Sea level changes are most noticeable in straits or other narrow places. If you observe, you will notice with the naked eye how quickly the water leaves or comes in. Sometimes it rises five meters in a few minutes.
As we have already found out, changes in sea level are caused by the impact on the earth’s crust of its constant satellite, the Moon. But how does this process happen? To understand what a tide is, it is necessary to imagine in detail the interaction of all the planets in the solar system.
The Moon and Earth are in constant dependence on each other. The Earth attracts its satellite, which, in turn, tends to attract our planet. This endless rivalry allows us to maintain the required distance between two cosmic bodies. The Moon and Earth move in their orbits, sometimes moving away and sometimes approaching each other.
At the moment when the Moon comes closer to our planet, the earth's crust bends towards it. This causes water to ripple on the surface of the earth’s crust, as if it is trying to rise higher. The separation of the earth's satellite causes a decline in the level of the World Ocean.
Tidal interval on Earth
Since the tide is a regular phenomenon, it must have its own specific interval of movement. Oceanologists were able to calculate the exact time of the lunar day. This term is usually used to describe the Moon’s revolution around our planet; it is slightly longer than the twenty-four hours we are used to. Every day the tides shift by fifty minutes. This time period is necessary for the wave to “catch up” with the Moon, which moves thirteen degrees during the Earth’s day.
The influence of ocean tides on rivers
We have already found out what a tide is, but few people know about the influence of these ocean fluctuations on our planet. Surprisingly, even rivers are affected by the ocean tides, and sometimes the results of this interference can be incredibly frightening.
During high tides, a wave entering the river mouth encounters a stream of fresh water. As a result of the mixing of water masses of different densities, a powerful shaft is formed, which begins to move at tremendous speed against the flow of the river. This flow is called boron, and it is capable of destroying almost all living things in its path. A similar phenomenon washes away coastal settlements and erodes the coastline in a few minutes. Bor stops as suddenly as it started.
Scientists have recorded cases when a powerful boron turned rivers back or stopped them completely. It is not difficult to imagine how catastrophic these phenomenal events of tidal action became for all the inhabitants of the river.
How do tides affect marine life?
Not surprisingly, tides have a huge impact on all organisms that live in the depths of the ocean. The hardest thing is for small animals living in coastal zones. They are forced to constantly adapt to changing water levels. For many of them, the tides are a way to change their habitat. During high tides, small crustaceans move closer to the shore and find food for themselves; the ebb wave pulls them deeper into the ocean.
Oceanologists have proven that many marine life are closely related to tidal waves. For example, some species of whales have a slower metabolism during low tides. In other deep-sea inhabitants, reproductive activity depends on wave height and amplitude.
Most scientists believe that the disappearance of phenomena such as fluctuations in the level of the World Ocean will lead to the extinction of many living beings. Indeed, in this case, they will lose their power source and will not be able to adjust their biological clock to a certain rhythm.
Earth's rotation speed: is the influence of tides significant?
For many decades, scientists have been studying everything related to the term “tide”. This is a process that brings more and more mysteries every year. Many experts associate the speed of the Earth's rotation with the action of tidal waves. According to this theory, under the influence of tides they are formed. On their way, they constantly overcome the resistance of the earth's crust. As a result, the planet’s rotation speed slows down, almost imperceptibly for humans.
By studying sea corals, oceanologists found that several billion years ago the earth's day was twenty-two hours. In the future, the rotation of the Earth will slow down even more, and at some point it will simply become equal to the amplitude of the lunar day. In this case, as scientists predict, the tides will simply disappear.
Human activity and the amplitude of oscillations of the World Ocean
It is not surprising that humans are also susceptible to the effects of tides. After all, it consists of 80% liquid and cannot help but respond to the influence of the Moon. But man would not be the crown of nature’s creation if he had not learned to use almost all natural phenomena to his advantage.
The energy of a tidal wave is incredibly high, so for many years various projects have been created to build power plants in areas with a large amplitude of movement of water masses. There are already several such power plants in Russia. The first was built in the White Sea and was an experimental option. The power of this station did not exceed eight hundred kilowatts. Now this figure seems ridiculous, and new power plants using tidal waves are generating energy that powers many cities.
Scientists see the future of Russian energy in these projects, because they allow us to treat nature more carefully and cooperate with it.
Ebbs and flows are natural phenomena that, not so long ago, were completely unexplored. Each new discovery by oceanographers leads to even greater questions in this area. But perhaps one day scientists will be able to unravel all the mysteries that the ocean tide presents to humanity every day.
Most of the volume of outer space is empty space. But here and there spherical clumps of matter - planets, moons, stars - rush past each other in a gigantic dance.
While performing their cosmic movements, they act on each other with the force of gravity, causing swelling of ocean waters on the surfaces of the planets. Gravity is the force of attraction that acts between all material objects without exception.
What are tides?
Ocean tides are the regular rise and fall of the water level of the World Ocean in response to gravitational influences, that is, to the forces of attraction. When the ocean waters rise to their highest level, which happens every 13 hours, it is called high tide. When the water reaches its lowest point, it is called low tide. If you come to relax on a sea beach at high tide, you observe the effect of worlds rushing past the Earth in the eternal darkness of space.
Related materials:
Why are there no ebbs and flows in the Black Sea?
What causes hot flashes?
The Sun, Moon and other bodies of the solar system influence the water and land of the Earth by the force of their gravity. But only the Moon and the Sun have a practical influence. The sun, although very far away (149 million kilometers), is so massive that its gravitational force is strong.
The Moon is very small (its mass is 1/81 of the mass of the Earth), but it has a pronounced gravitational effect on the Earth due to its close distance from it (380,000 kilometers).
Interesting fact: When the Sun, Moon and Earth are on the same line, that is, on a new moon, the tides are especially strong.
Despite the strong gravity of the huge Sun, the small Moon, due to its proximity to the Earth, has a much greater influence on the tides. In addition, the gravitational force of the Moon varies noticeably from area to area of the earth's surface. These changes are due to the different distances of different parts of the earth's surface from the Moon at any given time.
Contents of the article
Ebbs and flows, periodic fluctuations in water levels (rises and falls) in water areas on Earth, which are caused by the gravitational attraction of the Moon and Sun acting on the rotating Earth. All large water areas, including oceans, seas and lakes, are subject to tides to one degree or another, although they are small in lakes.
Reversible waterfall
(reversing direction) is another phenomenon associated with tides in rivers. A typical example is the waterfall on the Saint John River (New Brunswick, Canada). Here, through a narrow gorge, water during high tide penetrates into a basin located above the low water level, but slightly below the high water level in the same gorge. Thus, a barrier arises, flowing through which water forms a waterfall. During low tide, water flows downstream through a narrowed passage and, overcoming an underwater ledge, forms an ordinary waterfall. During high tide, a steep wave that penetrates the gorge falls like a waterfall into the overlying basin. The backward flow continues until the water levels on both sides of the threshold are equal and the tide begins to ebb. Then the waterfall facing downstream is restored again. The average water level difference in the gorge is approx. 2.7 m, however, at the highest tides, the height of the direct waterfall can exceed 4.8 m, and the reverse one - 3.7 m.
Greatest tidal amplitudes.
The world's highest tide is generated by strong currents in Minas Bay in the Bay of Fundy. Tidal fluctuations here are characterized by a normal course with a semi-diurnal period. The water level at high tide often rises by more than 12 m in six hours, and then drops by the same amount over the next six hours. When the effect of the spring tide, the position of the Moon at perigee and the maximum declination of the Moon occur on the same day, the tide level can reach 15 m. This exceptionally large amplitude of tidal fluctuations is partly due to the funnel-shaped shape of the Bay of Fundy, where the depths decrease and the shores move closer together towards top of the bay.
Wind and weather.
Wind has a significant influence on tidal phenomena. The wind from the sea pushes the water towards the coast, the height of the tide increases above normal, and at low tide the water level also exceeds the average. On the contrary, when the wind blows from land, water is driven away from the coast, and sea level drops.
Due to the increase in atmospheric pressure over a vast area of water, the water level decreases, as the superimposed weight of the atmosphere is added. When atmospheric pressure increases by 25 mm Hg. Art., the water level drops by approximately 33 cm. The decrease in atmospheric pressure causes a corresponding increase in the water level. Consequently, a sharp drop in atmospheric pressure combined with hurricane-force winds can cause a noticeable rise in water levels. Such waves, although called tidal, are in fact not associated with the influence of tidal forces and do not have the periodicity characteristic of tidal phenomena. The formation of these waves can be associated either with hurricane force winds or with underwater earthquakes (in the latter case they are called seismic sea waves, or tsunamis).
Using tidal energy.
Four methods have been developed to harness tidal energy, but the most practical is to create a tidal pool system. At the same time, fluctuations in water levels associated with tidal phenomena are used in the lock system so that a level difference is constantly maintained, which allows energy to be generated. The power of tidal power plants directly depends on the area of the trap pools and the potential level difference. The latter factor, in turn, is a function of the amplitude of tidal fluctuations. The achievable level difference is by far the most important for power generation, although the cost of the structures depends on the area of the basins. Currently, large tidal power plants operate in Russia on the Kola Peninsula and in Primorye, in France in the Rance River estuary, in China near Shanghai, as well as in other areas of the globe.
| INFORMATION ABOUT TIDES IN SOME PORTS OF THE WORLD | ||||
| Port | Interval between tides | Average tide height, m | Height of spring tide, m | |
| h | min | |||
| m. Morris-Jessep, Greenland, Denmark | 10 | 49 | 0,12 | 0,18 |
| Reykjavik, Iceland | 4 | 50 | 2,77 | 3,66 |
| r. Koksoak, Hudson Strait, Canada | 8 | 56 | 7,65 | 10,19 |
| St. John's, Newfoundland, Canada | 7 | 12 | 0,76 | 1,04 |
| Barntko, Bay of Fundy, Canada | 0 | 09 | 12,02 | 13,51 |
| Portland, USA Maine, USA | 11 | 10 | 2,71 | 3,11 |
| Boston, USA Massachusetts, USA | 11 | 16 | 2,90 | 3,35 |
| New York, NY New York, USA | 8 | 15 | 1,34 | 1,62 |
| Baltimore, pc. Maryland, USA | 6 | 29 | 0,33 | 0,40 |
| Miami Beach Florida, USA | 7 | 37 | 0,76 | 0,91 |
| Galveston, pc. Texas, USA | 5 | 07 | 0,30 | 0,43* |
| O. Maraca, Brazil | 6 | 00 | 6,98 | 9,15 |
| Rio de Janeiro, Brazil | 2 | 23 | 0,76 | 1,07 |
| Callao, Peru | 5 | 36 | 0,55 | 0,73 |
| Balboa, Panama | 3 | 05 | 3,84 | 5,00 |
| San Francisco California, USA | 11 | 40 | 1,19 | 1,74* |
| Seattle, Washington, USA | 4 | 29 | 2,32 | 3,45* |
| Nanaimo, British Columbia, Canada | 5 | 00 | ... | 3,42* |
| Sitka, Alaska, USA | 0 | 07 | 2,35 | 3,02* |
| Sunrise, Cook Inlet, USA Alaska, USA | 6 | 15 | 9,24 | 10,16 |
| Honolulu, pc. Hawaii, USA | 3 | 41 | 0,37 | 0,58* |
| Papeete, about. Tahiti, French Polynesia | ... | ... | 0,24 | 0,33 |
| Darwin, Australia | 5 | 00 | 4,39 | 6,19 |
| Melbourne, Australia | 2 | 10 | 0,52 | 0,58 |
| Rangoon, Myanmar | 4 | 26 | 3,90 | 4,97 |
| Zanzibar, Tanzania | 3 | 28 | 2,47 | 3,63 |
| Cape Town, South Africa | 2 | 55 | 0,98 | 1,31 |
| Gibraltar, Vlad. UK | 1 | 27 | 0,70 | 0,94 |
| Granville,France | 5 | 45 | 8,69 | 12,26 |
| Leath, UK | 2 | 08 | 3,72 | 4,91 |
| London, UK | 1 | 18 | 5,67 | 6,56 |
| Dover, UK | 11 | 06 | 4,42 | 5,67 |
| Avonmouth, UK | 6 | 39 | 9,48 | 12,32 |
| Ramsey, Fr. Maine, UK | 10 | 55 | 5,25 | 7,17 |
| Oslo, Norway | 5 | 26 | 0,30 | 0,33 |
| Hamburg, Germany | 4 | 40 | 2,23 | 2,38 |
| * Daily tide amplitude. | ||||
Literature:
Shuleikin V.V. Physics of the sea. M., 1968
Harvey J. Atmosphere and ocean. M., 1982
Drake C., Imbrie J., Knaus J., Turekian K. The ocean is for itself and for us. M., 1982
Ebbs and flows are called periodic increases and decreases in water levels in the oceans and seas.
Twice during the day, with an interval of about 12 hours and 25 minutes, the water near the shore of the ocean or open sea rises and, if there are no obstacles, sometimes floods large spaces - this is the tide. Then the water drops and recedes, exposing the bottom - this is low tide. Why is this happening? Even ancient people thought about this, and they noticed that these phenomena are associated with the Moon. I. Newton was the first to point out the main reason for the ebb and flow of the tides - this is the attraction of the Earth by the Moon, or rather, the difference between the attraction of the Moon to the entire Earth as a whole and its water shell.
Explanation of ebb and flow of tides by Newton's theory
The attraction of the Earth by the Moon consists of the attraction of individual particles of the Earth by the Moon. Particles that are currently closer to the Moon are attracted by it more strongly, and particles that are more distant are attracted less. If the Earth were absolutely solid, then this difference in the force of gravity would not play any role. But the Earth is not an absolutely solid body, therefore the difference in the attractive forces of particles located near the surface of the Earth and near its center (this difference is called the tidal force) displaces the particles relative to each other, and the Earth, primarily its water shell, is deformed.
As a result, on the side facing the Moon and on the opposite side, water rises, forming tidal ridges, and excess water accumulates there. Due to this, the water level in other opposite points of the Earth decreases at this time - low tide occurs here.
If the Earth did not rotate and the Moon remained motionless, then the Earth, together with its watery shell, would always maintain the same elongated shape. But the Earth rotates, and the Moon moves around the Earth in about 24 hours 50 minutes. With the same period, tidal peaks follow the Moon and move along the surface of the oceans and seas from east to west. Since there are two such projections, a tidal wave passes over each point in the ocean twice a day with an interval of about 12 hours and 25 minutes.
Why is the height of the tidal wave different?
In the open ocean, the water rises slightly when a tidal wave passes: about 1 m or less, which remains practically unnoticeable to sailors. But off the coast, even such a rise in water level is noticeable. In bays and narrow bays, the water level rises much higher during high tides, since the shore prevents the movement of the tidal wave and water accumulates here during the entire time between low tide and high tide.
The highest tide (about 18 m) is observed in one of the bays on the coast in Canada. In Russia, the highest tides (13 m) occur in the Gizhiginskaya and Penzhinskaya bays of the Sea of Okhotsk. In the inland seas (for example, in the Baltic or Black), the ebb and flow of the tides are almost imperceptible, because masses of water moving along with the ocean tidal wave do not have time to penetrate into such seas. But still, in every sea or even lake, independent tidal waves with a small mass of water arise. For example, the height of tides in the Black Sea reaches only 10 cm.
In the same area, the height of the tide can be different, since the distance from the Moon to the Earth and the maximum height of the Moon above the horizon change over time, and this leads to a change in the magnitude of tidal forces.
Tides and Sun
The sun also affects the tides. But the tidal forces of the Sun are 2.2 times less than the tidal forces of the Moon.
During the new moon and full moon, the tidal forces of the Sun and Moon act in the same direction - then the highest tides are obtained. But during the first and third quarters of the Moon, the tidal forces of the Sun and Moon counteract, so the tides are smaller.
Tides in the air shell of the Earth and in its solid body
Tidal phenomena occur not only in the water, but also in the air shell of the Earth. They are called atmospheric tides. Tides also occur in the solid body of the Earth, since the Earth is not absolutely solid. Vertical fluctuations of the Earth's surface due to tides reach several tens of centimeters.
Practical use of tides
A tidal power plant is a special type of hydroelectric power station that uses the energy of tides, and in fact the kinetic energy of the Earth's rotation. Tidal power plants are built on the shores of seas, where the gravitational forces of the Moon and the Sun change the water level twice a day. Fluctuations in water levels near the shore can reach 18 meters.
In 1967, a tidal power station was built in France at the mouth of the Rance River.
In Russia, since 1968, an experimental TPP has been operating in Kislaya Bay on the coast of the Barents Sea.
There are PES abroad - in France, Great Britain, Canada, China, India, the USA and other countries.
