Man perceives many natural phenomena as self-evident. We are accustomed to summer, autumn, winter, rain, snow, waves and do not think about the reasons. And yet, why do waves form in the sea? Why do ripples appear on the surface of the water even in complete calm?

Origin

There are several theories explaining the origin of sea and ocean waves. They are formed due to:

• changes in atmospheric pressure;
• ebbs and flows;
• underwater earthquakes and volcanic eruptions;
• ship movements;
• strong wind.

To understand the mechanism of formation, one must remember that water is agitated and oscillates involuntarily - as a result of physical impact. A pebble, a boat, a hand touching it set the liquid mass in motion, creating vibrations of different strengths.

Characteristics

Waves are also the movement of water on the surface of a reservoir. They are the result of the adhesion of air particles and liquid. At first, water-air symbiosis causes ripples on the surface of the water, and then causes the water column to move.

Size, length and strength vary, depending on the strength of the wind. During a storm, powerful pillars rise to 8 meters and stretch in length for almost a quarter of a kilometer.

Sometimes the force is so destructive that it falls on the coastal strip, uproots umbrellas, showers and other beach buildings, demolishes everything in its path. And this despite the fact that fluctuations are formed several thousand kilometers from the coast.

All waves can be divided into 2 categories:

• wind;
• standing.

wind

Windmills, as the name implies, are formed under the influence of wind. Its gusts rush at a tangent, forcing the water and forcing it to move. The wind pushes the liquid mass forward in front of it, but gravity slows down the process, pushing it back. Movements on the surface, resulting from the influence of two forces, resemble ups and downs. Their peaks are called crests, and their bases are called soles.

Having found out why waves form on the sea, the question remains open as to why they make oscillatory movements up and down? The explanation is simple - the inconstancy of the wind. He then quickly and impetuously swoops, then subsides. The height of the crest, the frequency of oscillations directly depend on its strength and power. If the speed of movement and the strength of the air currents exceed the norm, a storm rises. Another reason is renewable energy.

Renewable energy

Sometimes the sea is completely calm, and the waves are formed. Why? Oceanographers and geographers attribute this phenomenon to renewable energy. Water fluctuations are its source and ways to keep the potential for a long time.

In real life, it looks like this. The wind creates a certain amount of vibration in the pond. The energy of these oscillations will last for several hours. During this time, liquid formations cover a distance of tens of kilometers and "moor" in areas where it is sunny, there is no wind, and the reservoir is calm.

standing

Standing or solitary waves occur due to shocks on the ocean floor, characteristic of earthquakes, volcanic eruptions, and also due to a sharp change in atmospheric pressure.

This phenomenon is called seiches, which is translated from French as "to sway." Seiches are typical for bays, gulfs and some seas; they pose a danger to beaches, structures in the coastal strip, ships moored at the pier and people on board.

constructive and destructive

Formations that overcome long distances and do not change shape and do not lose energy, hit the coast and break. At the same time, each run-up has a different effect on the coastal strip. If it washes the shore, it is classified as constructive.

The destructive surge of water falls with its power on the coast, destroying it, gradually washing away sand and pebbles from the beach strip. In this case, the natural phenomenon is classified as destructive.

Destruction is of different destructive power. Sometimes it is so powerful that it brings down slopes, splits cliffs, separates rocks. Over time, even the hardest rocks are destroyed. America's largest lighthouse was built at Cape Hatteras in 1870. Since then, the sea has moved almost 430 meters inland, washing away the coastline and beaches. This is just one of dozens of facts.

Tsunamis are a type of destructive water formations characterized by great destructive power. The speed of their movement reaches 1000 km / h. This is higher than that of a jet aircraft. At depth, the height of the tsunami crest is small, but near the coast they slow down, but increase the height to 20 meters.

In 80% of cases, tsunamis are the result of underwater earthquakes, in the remaining 20% ​​- volcanic eruptions and landslides. As a result of earthquakes, the bottom shifts vertically: one part of it sinks, and the other part rises in parallel. Fluctuations of different strength are formed on the surface of the reservoir.

Anomalous Assassins

They are also known as wanderers, monsters, anomalous, and more characteristic of the oceans.

Even 30-40 years ago, sailors' stories about anomalous water fluctuations were considered fiction, because eyewitness accounts did not fit into the existing scientific theories and calculations. A height of 21 meters was considered the limit for oceanic and sea vibrations.

Where do giant waves come from?

What causes the appearance of most waves in the oceans and seas, about the energy of the waves and about the most gigantic waves.

The main reason for the appearance of ocean waves is the influence of winds on the water surface. The speed of some waves can develop and even exceed 95 km per hour. Ridge from ridge can be separated by 300 meters. They travel great distances across the surface of the ocean. Most of their energy is used up before they reach land, perhaps bypassing the deepest place in the world- The Mariana Trench. And yes, they are getting smaller. And if the wind calms down, then the waves become calmer and smoother.

If there is a strong breeze in the ocean, then the height of the waves usually reaches 3 meters. If the wind starts to become stormy, then they can become 6 m. In a strong gale, their height can already be more than 9 m and they become steep, with abundant spray.

During a storm, when visibility is difficult in the ocean, the height of the waves exceeds 12 meters. But during a severe storm, when the sea is completely covered with foam and even small ships, yachts or ships (and not just fish, even the biggest fish) can simply get lost between 14 waves.

The beat of the waves

Large waves gradually wash away the shores. Small waves can slowly level the beach with sediment. Waves hit the shores at a certain angle, therefore, sediment washed away in one place will be carried out and deposited in another.

During the strongest hurricanes or storms, such changes can occur that huge stretches of the coast can suddenly transform significantly.

And not only the coast. Once, in 1755, very far from us, waves of 30 meters high blew Lisbon off the face of the earth, submerging the city's buildings under tons of water, turning them into ruins and killing more than half a million people. And it happened on a big Catholic holiday - All Saints' Day.

killer waves

The largest waves are usually observed along the Needle Current (or Agulhas Current), off the coast of South Africa. Here it was also noted highest wave in the ocean. Its height was 34 m. In general, the largest wave ever seen was recorded by Lieutenant Frederick Margo on a ship on its way from Manila to San Diego. It was February 7, 1933. The height of that wave was also about 34 meters. Sailors gave the nickname "killer waves" to such waves. As a rule, an unusually high wave is always preceded by the same deep depression (or dip). It is known that a large number of ships disappeared in such hollows-failures. By the way, the waves that form during the tides are not connected with the tides. They are caused by an underwater earthquake or volcanic eruption on the sea or ocean floor, which creates the movement of huge masses of water and, as a result, large waves.

It seems to be a banal question, but there are some interesting nuances.

Waves arise for various reasons: due to the wind, the passage of a ship, the fall of an object into the water, the attraction of the moon, an earthquake, an eruption of an underwater volcano or a landslide. But if they are caused by liquid displacement from a passing ship or a falling object, the attraction of the Moon and the Sun contributes to the appearance of tidal waves, and an earthquake can cause a tsunami, it is more difficult with wind.

Here's how it goes...

Here the matter is in the movement of air - there are chaotic whirlwinds in it, small at the surface and large in the distance. When they pass over a reservoir, the pressure decreases, and a bulge forms on its surface. The wind begins to push harder on its windward slope, which leads to a pressure difference, and because of it, the air movement begins to "pump" energy into the wave. In this case, the speed of the wave is proportional to its length, that is, the longer the length, the greater the speed. Wave height and wave length are related. Therefore, when the wind accelerates the wave, its speed increases, therefore, the length and height increase. True, the closer the wave speed is to the wind speed, the less energy the wind can give to the wave. If their speeds are equal, the wind does not transfer energy to the wave at all.

Now let's look at how waves form in general. Two physical mechanisms are responsible for their formation: gravity and surface tension. When some of the water rises, gravity tries to bring it back, and when it goes down, it displaces neighboring particles, which also try to come back. The force of surface tension does not care which way the surface of the liquid is bent, it acts in any case. As a result, water particles oscillate like a pendulum. Neighboring areas are “infected” from them, and a surface traveling wave arises.

Wave energy is well transmitted only in the direction in which the particles can move freely. It is easier to do this on the surface than at depth. This is because the air does not create any restrictions, while at a depth the water particles are in very cramped conditions. The reason is poor compressibility. Because of it, the waves can travel long distances on the surface, but decay very quickly in depth.

It is important that during the wave the fluid particles almost do not move. At great depths, the trajectory of their movement has the shape of a circle, at shallow depths - an elongated horizontal ellipse. Thanks to this, ships in the harbor, birds or pieces of wood sway on the waves without actually moving on the surface.

A special type of surface waves are the so-called killer waves - giant solitary waves. Why they occur is still unknown. They are rare in nature and cannot be simulated in the laboratory. However, most scientists believe that killer waves are formed due to a sharp decrease in pressure over the surface of the sea or ocean. But a more thorough study of them lies ahead.

Here we are in detail

We have long been accustomed to many phenomena occurring on our planet, without thinking at all about the nature of their occurrence and the mechanics of their action. This is climate change, and the change of seasons, and the change of time of day, and the formation of waves on the sea and in the oceans.

And today we just want to pay attention to the last question, the question of why waves form on the sea.

Why do waves form in the sea

There are theories that waves in the seas and oceans arise due to pressure drops. However, these are often just the assumptions of people who quickly try to find an explanation for such a natural phenomenon. In reality, things are somewhat different.

Remember what makes the water "worry". This is a physical effect. Throwing something into the water, running a hand over it, hitting the water sharply, vibrations of different sizes and frequencies will certainly begin to go through it. Based on this, it can be understood that waves are the result of a physical impact on the surface of the water.

However, why do large waves appear on the sea, coming to the shore from afar? Another natural phenomenon is to blame - the wind.

The fact is that gusts of wind pass over the water along a tangent line, exerting a physical effect on the sea surface. It is this action that pumps water and makes it move in waves.

Someone, of course, will ask another question about why the waves on the sea and in the ocean move with oscillatory movements. However, the answer to this question is even simpler than the very nature of waves. The fact is that the wind has a non-permanent physical effect on the surface of the water, because it is directed towards it by gusts of different strength and power. This affects the fact that the waves have a different size and frequency of oscillation. Of course, strong waves, a real storm, occur when the wind exceeds the norm.

Why are there waves on the sea without wind

A very reasonable nuance is the question of why there are waves on the sea even if there is absolute calm, if the wind is completely absent.

And here the answer to the question will be the fact that water waves are an ideal source of renewable energy. The fact is that waves are able to store their potential for a very long time. That is, the wind that brought the water into action, creating a certain number of oscillations (waves), may be enough for the wave to continue its oscillation for a very long time, and the wave potential itself has not exhausted itself even after tens of kilometers from the point of origin of the wave.

That's all the answers to questions about why there are waves on the sea.

Waves are created by the wind. Storms create winds that affect the surface of the water, causing ripples. Just like the ripples in your cup of coffee after surfing when you blow on it. The wind itself can be seen on weather forecast maps: these are low pressure zones. The greater their concentration, the stronger the wind will be. Small (capillary) waves initially move in the direction the wind is blowing. The stronger and longer the wind blows, the greater its effect on the surface of the water. Over time, the waves begin to increase in size. As the wind continues to blow and the waves generated by it continue to be affected by it, small waves begin to grow. The wind has a greater effect on them than on a calm surface of the water. The size of a wave depends on the speed of the wind that forms it. Wind blowing at some constant speed will be able to generate a wave of a certain size. And as soon as the wave reaches its maximum possible size with a given wind, it becomes “fully formed”. The generated waves have different wave speeds and periods. (See wave terminology for more details.) Long period waves travel faster and travel longer distances than their slower counterparts. As they move away from the source of the wind (spread), the waves form lines of surfs (swells), which inevitably roll onto the shore. You are probably already familiar with the concept of "wave set" (wave set)! Waves that are no longer affected by the wind that generated them are called bottom waves (groundswell). This is exactly what surfers are looking for! What affects the size of the surf (swell)? There are three main factors that affect the size of waves on the high seas: Wind speed - the higher it is, the larger the wave will be. The duration of the wind is similar to the previous one. Fetch (fetch, "coverage area") - again, the larger the coverage area, the larger the wave is formed. As soon as the influence of the wind on them stops, the waves begin to lose their energy. They will move until the moment when the protrusions of the seabed, or other obstacles in their path (a large island for example) absorb all the energy. There are several factors that affect the size of a wave at a particular location in the surf. Among them: The direction of the surf (swell) - will it allow us to get the swell to the place we need? The ocean floor is a swell moving from the depths of the ocean to the reef, forming large waves with barrels inside. A shallow long ledge stretching towards the shore will slow down the waves and they will lose their energy. Tides - some sports are completely dependent on it. Find out more in the section on how the best waves appear.