What is quicksand in the desert. On the English coasts. What to do if you get caught in quicksand

Terrible is Nature in her wrath. In her arsenal - rivers of boiling lava, giant waves tsunamis, devastating earthquakes, bottomless swamps, floods. There is another terrible weapon. This quicksand, which have long been called "dry swamps".

Quicksand Legends

They scare children and travelers, they are told by old people instead of bedtime stories. Only unlike fictional stories, quicksand is a terrible reality that people living on the coasts most often face. Imagine: a storm, a ship in distress, desperate people. And suddenly, in the distance, the shore is the hope of salvation. With great difficulty, the ship approaches, but the cries of "hurrah" are replaced by exclamations of horror. The ship begins to slowly sink into the coastal sand. People try to save themselves, but, alas, few succeed.

Such cases, although they were not rare, but still almost all were counted. But the number of people who disappeared during walks cannot be counted at all. The sand underfoot suddenly turns into a trap, a person panics, begins to flounder and drowns.

Where are the most dangerous places with quicksand?

This is the Goodwin Shoals on the South Foreland. The second name is "Cemetery of ships". It looks intimidating: the skeletons and sides, randomly scattered along the coast, are covered with sand. Elsewhere, only the tip of the mast can be seen. A gloomy spectacle.

Alaska
This is Tarnagen Fjord.

Jamaica
This is the place where the city of Port Royal once stood, which disappeared in the 17th century. The original version - in 1692 there was an earthquake. The impact of the elements was powerful, the tidal wave destroyed the city, and the sea swallowed it. In 1992, scientists were able to prove that the city really drowned, but not in water. He's another victim of quicksand.

Islands Caribbean

Coast of Canada
In principle, quicksand can be found anywhere there is water, sand, and rocks. That is, the shores of lakes and seas can be considered dangerous, as well as big rivers. On the outskirts of deserts, you can also fall into a trap arranged by quicksand.

How is quicksand formed?

If you remember school physics lessons, you can easily find the clue to the formation of quicksand. The phenomenon of this phenomenon lies in the ratio of the amount of sand and water, as well as their interaction. What does dry (and therefore safe) sand consist of? From countless grains of sand and air. What happens if you add water here? Water will begin to envelop each grain of sand, and a film will form around it. Since there are tiny dust particles on the sand grains, the cementing process begins, in which they take an active part. This is how a completely new substance is formed - viscous and very viscous.

So, in order for ordinary sand to turn into a quick danger, it needs to be wetted.. A bucket of water will not help, a constant source of water is needed, and the larger it is, the more terrible the danger. In coastal places it is a tidal wave. The rest are underground springs. The depth of the source is different. If the mass of sand is large, then the estimated depth can reach forty meters. Moreover, only such water sources that are practically in a vertical position or slightly inclined are suitable for creating fluctuations. On the surface, everything looks quite harmless: sand, here and there pebbles, a couple of bushes. Without special instruments, it is impossible to determine whether there is water in this place, whether the sand is wet, and what is the extent of the danger.

And the water at this time works, constantly wetting the layers of sand, provokes its shedding. From above, this process is invisible, even specialists cannot determine it. But it is worth getting here any heavy object, and the trap works. Begins the process of suction, pulling deep.

How to check if there is quicksand in this place?

It's better not to. Don't know the area? Walk around the pleasant sand for bare feet. This measure is desirable everywhere and mandatory for those places where the trap has worked at least once. Usually in such areas there is a rescue service and there are warning signs.

Any chance of getting out of the quicksand?

The answer is unequivocal - yes. And now the big BUT. Only those who know what and how to do and will not be at a loss, that is, will be able not to panic, have a chance.

The actions are simple: lie on your back, try to spread your arms and legs, that is, take as much as possible more space. If you shrink into a ball, then the weight will press on one place, and the body will begin to sink faster. Usually both legs are the first to fall into the trap, sometimes one gets stuck - this can be considered a real success. Lying on your back, arms outstretched, you need to slowly, without sudden movements, pull out your legs. The process can take up to an hour, but be patient and persevere - your life is worth it. After you free your legs, you need to determine where you came from. There, on that side, is a safe hard surface. Row there, moreover, in literally this word. Swim across the sand and best on your back. You can not? Carefully roll over onto your stomach and, pushing off with your arms and legs, “swim”. And remember: any sudden movement - and you will be pulled into the sand.

Quicksand - unique phenomenon, as, indeed, and all other inventions of Nature.

The phenomenon of quicksand in most people is associated with terrible pictures of a person being pulled deep into the abyss.

Many see mysticism in this, tie the influence of cosmic or otherworldly forces. But how does everything really happen and is quicksand really so dangerous? How are they formed and how not to become a victim of this natural phenomenon?

Physical explanation and types of quicksand

The depth of quicksand can reach several meters, and may be only a few centimeters. From the point of view of physics, the explanation for quicksand is very simple and depends on the ratio and interaction of sand and water.

Sand grains are enveloped in water, and a film forms around them. There is air between the grains of sand, but with an increase in the amount of water, the air is displaced, and a mixture of sand and water is formed, the properties of which differ significantly from the mixture of sand, water and air.

There are two types of these sands:

1. With a wet surface. They are found on the shores of lakes, rivers, seas, where rising springs often come across. On top there may be a thin crust of silt formed from a fine fraction of sand.

2. With a dry surface. Found in deserts and rocky areas.

The reason is the source of water
A prerequisite for the formation of quicksand is a large source of water, which is located at a depth of several meters, and sometimes several tens of meters.

These springs provoke shedding of sand. In most cases, they try to break out with great force, rising as close to the surface as possible and enveloping individual grains of sand with water.

Thus, a loose sandy mass impregnated with water is formed, which for some time retains its balance. When any object hits here, the structure collapses, and physical forces try to push back the displaced sand.

Suction occurs. The question arises: can any source of water cause quicksand? Such a source can be one that moves in an inclined horizontal direction or almost in a vertical direction.

It is sometimes impossible to determine the location of such sand. From above, it looks quite reliable and there is no doubt whether it is possible to move on such a surface. Grass and flowers can grow here, however, if there is a similar sand formation in a rocky area, it is better to bypass it.

It is simply impossible to check whether a nearby source of water provoked the appearance of quicksand.

Is it possible to get out?

Statistics show that tragic incidents involving falling into quicksand are very common. Why is it so difficult or almost impossible to get out of the whirlpool of sand?

The fact is that it is very viscous, so any sudden movements cause even more resistance, despite the fact that the density of quicksand is only one and a half times greater than the density of water.

You can get out of the elements only if you move very smoothly, or even better, try to lie on your back, freeing your legs, and thus, as it were, float on the sand. In this case, you can keep the balance for a certain time and wait for the arrival of rescuers.

In response to the sharpness, the sand mass seems to harden. Independent attempts to pull out, for example, a leg form a rarefaction of air. There is a huge force pulling the leg back. The effort required to lift a leg can be compared to the weight of a car.

In dry sand, everything is different: a person buried even up to his neck can gradually get out of it on his own, because when moving slowly, air first enters the free space, and then grains of sand fill the niche. In quicksand, there is no such air, and the suspension is comparable in consistency to jelly, and the slowly moving mass does not have time to fill the resulting cavity, forming a vacuum.

Other causes

Quicksand occurs most often not in deserts, as many people think, but in rocky areas and in areas of frequent tides. known zone with dangerous tides is the Gulf of Morecambe, in particular the city of Arnside, located in England. At low tide, the bottom quickly dries up and becomes a trap.

The tide rises ten meters and covers everything that is in the zone of quicksand.

Another reason for the appearance of quicksand can be static charges arising from the mutual friction of sand grains. Since they are all charged in the same way, the cohesion is weakened and the surface becomes unstable. Quicksand is found in Canada, on the islands of the Caribbean, in England. There is a place in Alaska where the territory with treacherous sands stretches for 80 km, and not far from here there is a special rescue service in case someone falls into the trap of nature.

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“Do you know what quicksand is? They can suck you in and it's impossible to get out of them!" We used to scare each other when we were kids. For many, stories about quicksand have remained a children's horror story. I myself for a long time believed that this was an invention of writers who write adventure novels. But this a natural phenomenon actually exists. And today we will reveal everything « terrible secrets» Quicksand.

nature of quicksand

The process of formation of quicksand in the coastal zone

Under the influence of gravity (i.e. when someone or something steps on quicksand) grains of sand begin to move faster, thereby "suck" the victim down. Simply put, you don't just fall through, but the sand also helps you in this. At the same time, wet grains of sand tightly wrap around the legs due to the same force of surface tension of water. When you try to free yourself, rarefaction of air occurs, which pulls the trapped person back with force.

To get out of the trap of quicksand, you need to make an effort comparable to lifting a car. In this case, you will have to pull your hair, like Baron Munchausen. The prospect is depressing ... However You can still get out of the sand on your own. But how?

Death trap or endurance test?

To get out of a quicksand trap, you need to stop resisting it. (Note. This reminded me of one well-known psychological trick. Don’t like the situation? Stop resisting, and it will go away on its own.) Quicksand is, at its core, a Newtonian fluid. Any attempt at resistance is met with strong opposition. But if you completely relax, you can win over the sand. Very slowly and smoothly, you need to try to lie on your back or stomach. Then, just as slowly, move to the edge of the quicksand and gradually crawl out of it to freedom.

Where are quicksands found?

Even technology can fall victim to quicksand...

In deserts, water flows can pass under a layer of sand, inside limestone deposits. Some of them shoot up like underground fountains. And in the same way they "beat" the sand, turning it into quicksand. Such areas are even more difficult to recognize: outwardly, it can remain dry under the scorching sun of the desert and even overgrow with grass. But it is worth stepping on - and you are in a trap. The Sahara desert is best known for such "surprises". a large underground river flows under it.

The quicksands of the Sahara Desert

Quicksand can even occur along the banks of rivers and lakes. But most often their depth and scale are not so great, and they do not pose a danger.

Quicksand in the intertidal zone

Be careful! Quicksands!

Walking somewhere in nature, enjoying the charm of flowering plants, listening to birds whistling cheerful songs, you can accidentally be trapped in quicksand. But you should immediately warn that everything is not so scary, as shown in some films of the "horror" genre. Yes, of course, it is better to avoid them, but at the same time, you should not be afraid. There are several consistent rules, the knowledge of which will help to avoid such situations.

What exactly is quicksand? It's really interesting, but not at all peculiar. A mixture of fine-grained material, clay and water (in desert places - a mixture of sand and air). It looks solid, but becomes unstable when pressure is applied to its surface. It is formed when water oversaturates such soil. Ordinary, natural origin sand (quarry, mountain, sea) consists of densely packed grains that form a rigid mass (approximately 25 to 30 percent of the space between the grains is filled with water or air). Since many grains of sand are elongated, they can separate, and then the voids will be from 30 to 70 percent of the mass. This mechanism is similar to a house of cards when the space between the cards is significantly larger than the space they occupy. The liquid contributes to the creation of liquefied soil, which is not able to withstand the weight load.

Quicksand can form in stagnant and flowing upward water (as in artesian springs). Water jets directed upwards resist and inhibit soil particles. Saturated precipitation may look quite solid, but a little on its surface initiates liquefaction. This causes the sand to form into a slurry and lose strength. Cushioned water produces quicksand, liquefied sediments, and a spongy, liquid-like soil texture. Objects entering such an environment sink to a level at which their weight is equal to the weight of the displaced mixture (from soil and water). Liquefaction is a special case of the phenomenon under consideration. So, in the event of an earthquake, the pore pressure instantly increases in shallow areas. Wet liquefied soil loses its strength, which leads to the collapse of buildings and other objects located on its surface.

Quicksands form where they exist natural springs, in marshy or wet places, near rivers, on beaches, although most often they are not so easy to identify. If you suddenly get into them, they retreat quickly and gently, reacting with an interval of a couple of seconds. They are, that is, at rest they are a solid substance (gel-like form), but the slightest impact on them causes a sharp decline viscosity. In deserts, they are also found, but extremely rarely, where placers of sand appear, for example, on dunes. But the decline is limited to a few centimeters, because as soon as the air in the voids between the sand grains is removed (and this happens quickly), they re-compact.

It should be said right away - the widespread opinion that quicksand can drag a person headlong is an exaggeration. However, they are really dangerous, because it is very difficult to free yourself without outside help. Caught in sand captivity, people died from dehydration, sunburn, drowned during high tides, because they did not have time to rescue them.

How quicksand is formed

It is absolutely impossible to simply, by eye, determine that the place in front of you is deadly. The sun dries the top layer of sand, sometimes even some kind of vegetation appears on it. It seems that this is the most ordinary sand. As a matter of fact, the way it is - ordinary, only very small, like dust.

The main thing in the occurrence of the phenomenon is that the properties of dry and wet sand are different and strongly depend on how much water it contains. Dry sand is free-flowing, since the adhesion forces between individual grains of sand are provided only by the roughness of their surfaces. If the sand is moistened, the adhesion forces will increase many times over. Water covers the grains of sand with a thin film, the forces of surface tension of which cause them to stick together. At the same time, a significant part of the space between individual grains of sand remains filled with air.

If water fills the space between the grains of sand completely, the surface tension forces cease to act. A fluid and viscous water-sand mixture is formed. In fact, the unique properties of quicksand - the ability to rapidly "suck" their victims, and then keep them literally in stone captivity - are explained precisely by its high humidity.

Why is quicksand addictive?

Sand becomes quicksand if there is a fairly powerful underground source under it. A stream of water moving upwards, as it were, “beats up” the sandy surface above it. The mutual arrangement of grains of sand becomes unstable, but still remains. If a person steps on such a surface, the entire structure will collapse under his weight.

The grains of sand move along with the body of the fallen man. The structure of the sand mass is changing. Now the grains of sand are tightly pressed against each other, and the forces of the surface tension of the water film form a concrete frame around his legs. Since there is no air between the grains of sand, any movement creates a rarefied space. Raw sand, which has a high viscosity, does not have time to fill the cavities formed during movement, and the force of atmospheric pressure tends to return the shifting body back. It seems that the sand is sucking in.

Scientists believe that another reason for the formation of quicksand is static charges resulting from the friction of grains of sand. Since they are all of the same name, the cohesion between the grains of sand is weakened.