Quicksand (quicksand) - sands supersaturated with air (gas or hot vapors, in the desert), moisture from ascending sources and, as a result, capable of sucking deep into objects, animals and humans that fall on them.

Quicksand when at rest, it seems solid, but it has the ability to suck in objects that are heavier and denser in mass and density. In other words, it is the same as a swamp. The only difference between them is that the swamp is in a permanent liquid environment, and the sand turns into quicksand with an increase in the level of underwater waters and currents.

Two kinds of quicksand

1. Quicksand with wet surface

The wet surface of quicksand is found along the shores of seas, lakes and rivers (where ascending springs are usually common).

Often the surface of such places consist of a thin crust of silt. Silt is a finer “pulverized” fraction of sand, which, over time, and the friction of fine sand particles turn into silt.

2. Quicksand with dry surface

The dry surface of quicksand is found in arid deserts and where there is no water nearby. Their fluctuation consists in the increase of underwater rivers and currents, up to the level of the surface of the sand base. The upper part of the sand remains dry and a person can easily get into it.

Quicksand is not bottomless at all. Usually their depth ranges from a few centimeters to several meters.

Due to the high density of quicksand, a person or animal cannot completely drown in it.

Quicksand itself is safe, but due to the fact that it significantly restricts the ability to move, a person bogged down in it becomes vulnerable to other dangers: high tide, solar radiation, dehydration and others.

When falling into quicksand, as well as in a swamp, you should try to lie on your back with your arms spread wide. It is necessary to get out slowly and smoothly, without making sudden movements.

However, people are dying in quicksand.

Arnside (England) is located near Morecambe Bay, infamous for its high sea tides and quicksands, in which almost 150 people have died since 1990 alone. At low tide, the water here recedes far from the coastline, and the exposed sandy bottom quickly dries up, creating the illusion of a great beach, which is actually fraught with mortal danger. People walking on the dry surface are trapped in quicksand, and the fast tide, which rises nine meters, covers the unfortunate people with their heads.

In Alaska, there is the beautiful Tarnagen Fjord, which is 80 km long. In 1988, two tourists, the Dixons, decided to ride along the coast at low tide. Three hundred meters from the shore, their car got stuck in the sand. Adeanna got out of the car to push her from behind. Soft muddy ground swam under her feet, and the woman got stuck in it up to her knees. Quicksand squeezed her legs like in a vise. Jay tried to help his wife, but in three hours he managed to dig up only one leg. When he finally thought to call someone for help, time was hopelessly lost - the tide had already begun. The rescuers arrived very quickly. They dived into the icy water and until the last moment tried to free Adeanna's leg, but could not do anything, and the woman drowned.

Large, heavy objects sometimes sink into quicksand with disastrous consequences.

Ordinary sands become quicksand for another reason: as a result of an earthquake. True, in these cases, their "quickness" persists only for a very short time. In 1692, in Jamaica, quicksand swallowed up an entire area of ​​the city of Port Royal, then more than two thousand people died. Port Royal was a very large rich port, where the largest slave market was located. Since 1674, by appointment of King Charles II of England, the famous pirate Henry Morgan became the mayor of the city. However, the place for the construction of the city was chosen extremely unsuccessfully - Port Royal was located on a 16-kilometer sand spit. Its top layer is still saturated with water, and below is a mixture of gravel, sand and fragments.

In the 19th century, a freight train derailed on the Colorado Bridge and plunged into a "dry" river bed that had become quicksand due to a recent downpour. Railway workers found most of the train, but the 181-ton steam locomotive sank without a trace.

Warning sign near quicksand

Warning signs are set up in the quicksand area, but this does not always stop people.

Bear Grylls Sahara Quicksand

Undoubtedly, quicksand is one of the most dangerous places on earth. Usually the sun dries the top layer of sand, resulting in a thin hard crust on it, which may even have time to grow grass. But the illusion of reliability will instantly evaporate, as soon as you step on it, the soil will literally float from under your feet. The poor fellows who step on this sand, which seems to be solid ground, are instantly sucked in. The legs are squeezed by a hardened mass, and it is impossible to pull them out without outside help.

Quicksand alone cannot kill a person. Firstly, it will not be able to completely absorb a person, since it is a non-Newtonian fluid. However, if a person is not saved in time, then he can die from a number of other reasons. For example, from dehydration, solar radiation, various living creatures, or die under the water of the tide.

Many theories have been proposed about the quicksand phenomenon. Most of them, of course, turned out to be wrong. However, over time, the situation began to clear up. It turned out that the properties of wet sand significantly depend on the amount of water it contains. Moist sand grains easily stick together, showing a sharp increase in cohesive forces, which in dry sand are due only to surface irregularities and therefore are very small. The surface tension forces of the water films surrounding each grain of sand cause them to stick together. In order for the grains of sand to stick together well, water must cover the particles and their groups with a thin film, while most of the space between them must remain filled with air. If the amount of water in the sand is increased, then as soon as the entire space between the grains of sand is filled with water, the surface tension forces disappear and a mixture of sand and water is obtained, which has completely different properties. Thus, quicksand is the most common sand, under the thickness of which, at a depth of several meters, there is a fairly strong source of water.

Why do people fall into quicksand? It's all about the special structure of the arrangement of grains of sand. A stream of water coming from below whips up a loose pillow of grains of sand, which is in relative equilibrium for some time. The weight of a traveler wandering into such a place brings down the structure. The grains of sand, being redistributed, move along with the body of the victim, additionally, as if sucking the poor fellow into the soil layer. After that, the structure of the sand around the unfortunate person becomes completely different - tightly pressed wet grains of sand form a trap due to the surface tension of the water layer. When you try to pull your leg out, a rarefaction of air is formed, pulling the leg back with great force. To pull the leg out in this situation at a speed of 0.1 m/s, you need to apply a force equal to the force of lifting a medium-sized passenger car. So, when you get into quicksand, it’s better not to make sudden movements, but try to lie on your back and, arms outstretched, wait for help.

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.

Terrible is Nature in her wrath. In her arsenal - rivers of boiling lava, giant tsunami waves, devastating earthquakes, bottomless swamps, floods. There is another terrible weapon. These are quicksands, 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?

England
This is the city of Arnside, located on the coast of Morecambe Bay. The length of the strip of quicksand is 80 (!) meters - a giant trap.

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.

Caribbean Islands

Coast of Canada
In principle, quicksand can be found anywhere there is water, sand, and rocks. That is, the shores of lakes and seas, as well as large rivers, can be considered dangerous. 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 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 have a chance, that is, they will be able not to succumb to panic.

The actions are simple: lie on your back, try to spread your arms and legs, that is, take as much space as possible. 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, and, in the truest sense of the 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 is a unique phenomenon, just like all other inventions of Nature.

There are many more places on the planet that are better not to fall into accidentally. And one has to be very careful when going there. Quicksand is a good example of such places. There are many chilling stories about them. According to some legends, there are sands that can swallow a person completely in a few minutes (the sand dunes between North and South Wales have such a reputation). However, in order to perish, a lone traveler in desert places does not have to be dragged with his head. One day, a married couple drove their private car (an SUV, by the way) onto a seemingly safe sandbar at high tide. The wheels immediately sank into the sand. The woman who got out of the car also fell knee-deep, where her feet were as if squeezed by an iron grip. The husband could not save his wife - the ocean quickly hid her from her head.

Researchers have repeatedly taken up the study of the phenomenon of quicksand, and gradually the situation with them has become more or less clear. Undoubtedly, the properties of wet sand depend significantly on the amount of water it contains. Wet sand grains easily stick together, showing a sharp increase in cohesive forces, which in dry sand are due only to surface irregularities and therefore are very small.

The surface tension forces of the water films surrounding each grain of sand cause them to stick together. In order for the grains of sand to stick together well, water must cover the particles and their groups with a thin film, while most of the space between them must remain filled with air. If the amount of water in the sand is increased, then as soon as the entire space between the grains of sand is filled with water, the surface tension forces disappear and a mixture of sand and water is obtained, which has completely different properties. Thus, quicksand is the most common sand, under the thickness of which, at a depth of several meters, there is a fairly strong source of water.

Quicksand is most commonly found in hilly or tidal areas. Moving from the mountains, the streams of water move through channels carved inside the dolomite and limestone rocks. Somewhere it breaks through a stone and rushes up in a powerful stream. If a layer of sand is encountered along the way, then the stream of water coming from below can turn it into quicksand. The sun dries the top layer of sand, and a thin hard crust forms on it, on which grass can even grow. The illusion of well-being and tranquility will instantly evaporate, as soon as you step on it, the soil will float from under your feet.

Why do people fall into quicksand? The point is the resulting structure of the arrangement of grains of sand. A stream of water coming from below whips up a loose pillow of grains of sand, which is in relative equilibrium for some time. The weight of a traveler wandering into such a place brings down the structure.

The grains of sand, being redistributed, move along with the body of the victim, additionally, as if sucking the poor fellow into the soil layer. After that, the structure of the sand around the unfortunate person becomes completely different - tightly pressed wet grains of sand form a trap due to the surface tension of the water layer. When you try to pull your leg out, a rarefaction of air is formed, pulling the leg back with great force. The force required to lift the leg in such a situation is comparable to the weight of the car. If the sand were dry, then with slow movement, the air that was between the grains of sand would first come to the vacant place, and then the sand itself, crumbling, would fill the gap. Buried even up to the neck in ordinary sand, a person may well get out of it on his own (anticipating objections, let me remind you that in the White Sun of the Desert the hero was previously bound). In quicksand, a viscosity comparable to thick jelly will not allow this to be done.

The density of quicksand is about 1.6 times that of water, but this does not make it possible to swim in it. Due to the high humidity, the sand is viscous, and any attempt to move in it is met with strong opposition. The slowly flowing sandy mass does not have time to fill the cavity that appears behind the shifted object, and rarefaction, a vacuum, arises in it. The force of atmospheric pressure tends to return the object to its original place - it seems that the sand "sucks" its victim. Thus, moving in quicksand is possible, but only extremely slowly and smoothly, since the mixture of water and sand is inertial in relation to fast movements: in response to a sharp movement, it seems to harden.

For the formation of quicksand, the movement of water from the bottom up is necessary - which provides a tide or underground flow. In the Sahara desert, quicksands are formed in the zone of the existence of a large underground river, which people did not know about until the beginning of the era of sounding the structure of the earth's surface from a satellite. Sometimes, an earthquake can be the cause of such a zone. Or human activity. One day, while trying to drain the construction area of ​​the foundation of a high-rise building, a huge pump sucking water through a well went underground. Quicksand is often encountered by builders of buildings and the subway in St. Petersburg, where soils are oversaturated with water. In these places they are called quicksand.

Quicksand victims are not only lone travelers or animals. There is a place where ships are swallowed up by the sands: the South Foreland in England (the Goodwin Shoals) is world-famous as the “ship graveyard”. On a long shallow, there are wrecks of ships immersed in the sand. The sands tenaciously hold the victim, and it is almost impossible to save the ship, and sometimes the crew. Once the ship "Gelena Modjeska" became a victim of the Goodwin Sands, the cargo of which was estimated at 3 million dollars. For four days, eight rescue tugs tried to save the ship, but on the fifth day, the Helena Modjeska broke in half, and the cargo and the ship perished in the sands. And in 1954, in this place, quicksand sucked in a whole lighthouse that warned ships of danger. The tower went into the sand completely.