Most people associate the phenomenon of quicksand with scary images of a person being pulled deep into the abyss.

Many see mysticism in this and attribute the influence of cosmic or otherworldly forces. But how does everything really happen and are quicksand really that dangerous? How are they formed and how can you avoid becoming a victim of this natural phenomenon?

Physical explanation and types of quicksand

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

The grains of sand 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 are significantly different 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, and seas, where rising springs are often encountered. On top there may be a thin crust of silt formed from the fine sand fraction.

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

Reason: water source
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 sources provoke the 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 soaked in water is formed, which remains in balance for some time. When any object hits here, the structure collapses, and physical forces try to return 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 vertically.

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 you encounter such a sandy formation on rocky terrain, it is better to bypass it.

It is simply impossible to verify whether a nearby water source caused 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 greater resistance, despite the fact that the density of quicksand is only one and a half times greater than the density of water.

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

In response to the sharpness, the sand mass seems to harden. Independent attempts to pull out, for example, a leg create a vacuum of air. A huge force arises, pulling the leg back. The effort required to lift your 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. There is no such air in quicksand, and the suspension is comparable in consistency to jelly, and the slowly moving mass does not have time to fill the emerging cavity, forming a vacuum.

Other causes

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

The tide rises tens of meters and covers everything that is in the area of ​​quicksand.

Another reason for the appearance of quicksand can be static charges arising due to the mutual friction of sand grains. Since they are all charged at the same time, the adhesion weakens and the surface becomes unstable. There are quicksands in Canada, on the islands 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 nature’s trap.

Alaska has a lot a nice place- Tarnagen fjord. In 1988, two tourists, the Dixon couple, decided to ride along the coast at low tide. The car got stuck in the sand. Adrianna Dixon got out of the car and instantly fell into the ground up to her knees.

The husband tried to pull the woman out, but after suffering for several hours he was unable to free her from the trap. The sand was compressed and held the feet like cement. Dixon called rescuers, but the water was already rising in the fjord - the tide had begun. It was not possible to save the woman who fell into quicksand - the unfortunate woman drowned.

Quicksand is a moving sandy surface that can suck in any object. The rate of suction depends on the structure of the sand, the mass and volume of the foreign object and ranges from several minutes to several months.

There are many legends and creepy stories associated with quicksand. Most of them objectively reflect the terrible danger lurking under the surface of the sand, which at first glance seems so harmless.

In 2000, the US National Geographic Society released a movie about quicksand, shot in the tradition of Hollywood horror films, after watching which you are unlikely to want to sunbathe even on a well-maintained sandy beach.

Most of the legends about quicksand originated in England on the sea coasts, where for centuries there were dangerous areas that would suck in a person or animal who carelessly stepped onto the treacherous surface.

Here is an excerpt from Wilkie Collins' novel The Moonstone:

“Between the two rocks lies the worst quicksand on the whole Yorkshire coast. During the ebb and flow of the tide, something happens in their depths, causing the entire surface of the sands to fluctuate in the most unusual way... Secluded and scary place. No boat dares to enter this bay... Even birds fly away from the quicksand. The tide began to rise, and the terrible sand began to tremble. Its brown mass slowly rose, and then it all began to tremble...”

Back in the 19th century, most of these dangerous places in England it was buried and destroyed. There are currently no quicksands in densely populated areas.

Until now, scientists have not fully understood the nature of this dangerous phenomenon. Some researchers believe that the ability to suction is determined by the special shape of the sand grains. According to one of the hypotheses put forward by Russian physicist Vitaly Frolov, the mechanism of action of quicksand is due to electrical effects, as a result of which friction between grains of sand decreases and the sand becomes fluid.

If the fluidity extends to a depth of several meters, the soil becomes viscous and sucks in any massive body that gets into it. American geologist George Clark from the University of Kansas studied a unique phenomenon for many years and came to the conclusion that quicksand is ordinary sand mixed with water and having some properties of a liquid medium.

According to Clark, quicksand is not a natural phenomenon, but a special state of sand. The latter occurs, for example, on a surface periodically flooded by the tide, or if an underground river flows under a mass of sand. Typically, quicksand is located in hilly areas where underground water flows often change direction and can rise to the surface or go deeper.

When the water flow rises, it does not appear outwardly, although the surface of the earth suddenly becomes very dangerous. This happened in England in Arnside in 1999, when, in front of his parents’ eyes, sand sucked his four-year-old son up to his waist.

Fortunately, rescuers arrived in time and tragedy was averted. Arnside is located near Morecambe Bay, famous for its high tides.

At low tide, the water recedes 11 kilometers, exposing the sandy bottom of the bay. Those brave souls who dare to step on this sand, which seems like solid ground, are instantly sucked in. The legs become squeezed by a hardened mass, and it is impossible to pull them out without outside help. If this is not done in time, a person dies under the water of the tide, as happened with Adrianna Dixon.

Not only tidal beaches, but also the banks of some rivers are sometimes fraught with invisible danger.

Sable Island, located in Atlantic Ocean 180 kilometers from the coast of Canada, near which there are many reefs, which is why sea ​​vessels, it happened that they suffered a catastrophe there and were thrown ashore. A few months later, the sand sucked up the wreckage without leaving a trace. There are a lot of dangerous quicksand in Alaska; the longest of the peninsula's fjords, completely filled with quicksand, stretches for 150 kilometers.

There are also quicksands in the Sahara, one of the driest and lifeless deserts on the planet. Entire caravans disappear there without a trace. Tuareg nomads talk about heartbreaking screams coming from underground at night. They believe that these are the groaning souls of people swallowed up in the greedy belly of the desert.

Recently, Russian scientists made a discovery based on satellite photographs of the earth's surface - a powerful underground river flows under the desert. Perhaps the waters of this stream give some places in the desert the properties of fluidity.

Quicksand is most often found in hilly areas or tidal areas. Moving from the mountains, streams of water move through channels cut inside dolomite and limestone rocks. Somewhere it breaks through a stone and rushes upward in a powerful stream.

If a layer of sand is encountered along the way, the flow of water coming from below can turn it into quicksand. The sun dries out 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 swim from under your feet.

Why does a person fall into quicksand? The point is the resulting structure of the arrangement of grains of sand. The flow of water coming from below whips up a loose cushion of grains of sand, which is in relative equilibrium for some time. The weight of a traveler who wanders into such a place collapses 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 this, the structure of the sand around the unfortunate person becomes completely different - tightly pressed wet grains of sand form a trap due to the force of the surface tension of the water layer.

When you try to pull your leg out, a vacuum of air is formed, pulling the leg back with enormous force. The force required to lift a leg in such a situation is comparable to the weight of a car. If the sand were dry, then with slow movement, the air between the grains of sand would first come to the vacated space, and then the sand itself, crumbling, would fill the gap.

A person buried even up to his neck in ordinary sand can easily 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 tied up). In quicksand, a viscosity comparable to thick jelly will not allow this to be done.

The density of quicksand is approximately 1.6 times greater than the density of water, but this makes it impossible to swim in it. Due to the high humidity, the sand is viscous, and any attempt to move in it is met with strong resistance. The slowly flowing sand mass does not have time to fill the cavity that appears behind the displaced object, and a rarefaction or vacuum arises in it.

Force atmospheric pressure strives to return the object to its original place - it seems that the sand is “sucking in” its victim. Thus, it is possible to move in quicksand, but only extremely slowly and smoothly, since the mixture of water and sand is inertial with respect to rapid movements: in response to a sudden movement, it seems to harden.

It is difficult to even approximately estimate the number of victims of the deadly sands; in any case, it exceeds thousands, and perhaps tens of thousands. In 1692, in Jamaica, quicksand swallowed up an entire area of ​​the city of Port Royal, killing over two thousand people. Port Royal was a very large, wealthy port and home to the largest slave market.

Since 1674, by appointment of King Charles II of England, the famous pirate Henry Morgan became mayor of the city. However, the location for the construction of the city was chosen extremely poorly - 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 rock fragments.

On June 7, 1692, an earthquake began, and the sand under the city suddenly began to suck in buildings and people. Descriptions of the tragedy have been preserved in historical chronicles. Some city residents instantly fell underground, others were sucked in up to their knees or waist.

After the end of the earthquake, which lasted six minutes, the sand instantly turned into a solid mass, resembling cement, which held the people tightly in its vice. The unfortunates were suffocating, walled up alive in the ground.

Most died, unable to get out; their torsos sticking out of the sand were eaten by wild dogs. Back in the 19th century, on the site of the buried city, the remains of the walls of collapsed houses stuck out of the sand. But in 1907, another earthquake occurred, absorbing this evidence of the tragedy.

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

When quicksand is at rest, it seems solid, but it has the property of sucking into itself objects that are heavier and denser in mass and density. In other words, it is the same thing as a swamp. The only difference between them is that the swamp is in a constant liquid environment, and the sand turns into quicksand with an increase in the level of underwater waters and currents.

Two types of quicksand

1. Quicksand with a wet surface

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

Often the surface of such places consists of a thin crust of silt. Silt is a smaller “pulverized” fraction of sand, which over time and friction of small sand particles turns into silt.

2. Quicksand with a dry surface

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

Quicksand is not bottomless at all. Typically 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 is safe in itself, but due to the fact that it significantly limits the ability to move, a person stuck in it becomes vulnerable to other dangers: high tides, solar radiation, dehydration, and others.

If you get into quicksand, just like in a swamp, you should try to lie on your back with your arms spread wide. You need to get out slowly and smoothly, without making sudden movements.

However, people are dying in quicksand.

Arnside, England, is located near Morecambe Bay, notorious for its high tides and shifting sands, which have killed almost 150 people since 1990 alone. At low tide the water here recedes far from coastline, and the exposed sandy bottom quickly dries out, creating the illusion of an excellent beach, which in fact is fraught with mortal danger. People walking on the dry surface are trapped by quicksand, and the fast tide, which rises nine meters, covers the unfortunate people completely.

In Alaska there is a beautiful Tarnagen fjord, which is 80 km long. In 1988, two tourists, the Dixon couple, 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. The soft muddy soil floated under her feet, and the woman got stuck in it up to her knees. The quicksand squeezed her legs as if in a vice. Jay tried to help his wife, but in three hours he only managed to dig out one leg. When he finally decided to call someone for help, time was hopelessly lost - the tide had already begun. The rescuers rushed in very quickly. They dived into the icy water and tried until the last moment to free Adeanna’s leg, but they could not do anything, and the woman drowned.

Large, heavy objects sometimes fall into quicksand with catastrophic consequences.

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

In the 19th century, a freight train derailed on the Colorado Bridge and plunged into a “dry” river bed that had become choppy due to a recent rainstorm. Railway workers found most train, but the locomotive weighing 181 tons sank without a trace.

Warning sign near quicksand

Warning signs are placed in the area of ​​quicksand, but this does not always stop people.

Bear Grylls Sahara Quicksand

Quicksand is an ominous phenomenon present in many horror films. The inconspicuous flat surface of the sand suddenly begins to pull in the victim who has stepped on it. The more she tries to escape, the more the quicksand pulls in, eventually swallowing the person headlong. This terrible picture, of course, is more fiction than reality. However, quicksand does exist. Although their depth rarely exceeds several tens of centimeters, they can indeed pull in animals or even humans that have fallen to the surface. Moreover, which coincides with the ideas of the films, the sands really drag you in more and more, the more you try to get out of them.

The nature of quicksand is much simpler than it might seem, and there is no magic in explaining its action. This phenomenon can occur almost anywhere where there are the necessary factors for this, namely an underground source of water and sand. Quicksand is ordinary sand highly saturated with water to such an extent that the friction between the sand grains becomes negligible and the resulting substance can no longer hold objects on its surface. However, it is important to note that only very fine sand, with a dust-like structure, is suitable. Only it, mixed with water, can create a structure that absorbs matter.

There are several reasons why quicksand forms. Firstly, this is the release of groundwater in the form of springs to the surface of the Earth. If there is a sandy area in this place, then the formation of quicksand is quite possible. Another reason is an earthquake. Water from underground sources can also rise to the surface along the resulting faults. A human cause for the formation of quicksand is also possible. In the event of a water pipe break or waterlogging of the soil as a result of irrigation, water mixed with sand can also create a fluid mixture.

Even if you managed to find quicksand deep enough to get stuck in, then all the same, your situation is not hopeless. The first thing to do is to stop moving your arms and legs chaotically, trying to escape from the absorbing mass. Quicksand only absorbs an object when it moves. Most The best way to get out is to grab onto nearby bushes or hanging tree branches. You can also lean on a wide, strong support, such as a board. Even if none of this is nearby, it is still possible to get out. The main thing is that all movements are smooth. By gradually moving your hands, you can “swim” in quicksand. Slowly moving towards the shore, sooner or later you will reach a shallow place that will allow you to get out of the trap.

There are still many places on the planet that it is better not to accidentally visit. And you have to be very careful when going there. A good example of such places is quicksand. There are many chilling stories about them. According to some legends, there are sands that can completely swallow a person in a few minutes (the sand dunes between North and South Wales have this reputation). However, in order to die, a lonely traveler in desert places does not have to be dragged headlong. One day, a married couple drove their personal car (an SUV, by the way) onto a seemingly safe sandbank during the ocean's high tide. The wheels immediately sank into the sand. The woman who got out of the car also fell to her knees, where her feet seemed to be squeezed in an iron grip. The husband could not save his wife - the ocean quickly hid her completely.

Researchers have repeatedly taken up the study of the phenomenon of quicksand, and gradually the situation with them became more or less clear. Undoubtedly, the properties of wet sand depend significantly on the amount of water it contains. Moistened grains of sand easily stick together, demonstrating a sharp increase in adhesion forces, which in dry sand are caused only by surface unevenness and are therefore very small.

The forces of surface tension of the films of water surrounding each grain of sand cause them to stick together. In order for sand grains 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 sand grains is filled with water, the surface tension forces disappear and the result is a mixture of sand and water that has completely different properties. Thus, Quicksand is the most ordinary sand, under the thickness of which at a depth of several meters there is a fairly strong source of water.

Quicksand is most often found in hilly areas or tidal areas. Moving from the mountains, streams of water move through channels cut inside dolomite and limestone rocks. Somewhere it breaks through a stone and rushes upward in a powerful stream. If a layer of sand is encountered along the way, the flow of water coming from below can turn it into quicksand. The sun dries out 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 does a person fall into quicksand? The point is the resulting structure of the arrangement of grains of sand. The flow of water coming from below whips up a loose cushion of grains of sand, which is in relative equilibrium for some time. The weight of a traveler who wanders into such a place collapses 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 this, the structure of the sand around the unfortunate person becomes completely different - tightly pressed wet grains of sand form a trap due to the force of the surface tension of the water layer. When you try to pull your leg out, a vacuum of air is formed, pulling the leg back with enormous force. The force required to lift a leg in such a situation is comparable to the weight of a car. If the sand were dry, then with slow movement, the air between the grains of sand would first come to the vacated space, and then the sand itself, crumbling, would fill the gap. A person buried even up to his neck in ordinary sand can easily 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 tied up). In quicksand, a viscosity comparable to thick jelly will not allow this to be done.

The density of quicksand is approximately 1.6 times greater than the density of water, but this makes it impossible to swim in it. Due to the high humidity, the sand is viscous, and any attempt to move in it is met with strong resistance. The slowly flowing sand mass does not have time to fill the cavity that appears behind the displaced object, and a rarefaction or vacuum arises in it. The force of atmospheric pressure tends to return the object to its original place - it seems that the sand is “sucking in” its victim. Thus, it is possible to move in quicksand, but only extremely slowly and smoothly, since the mixture of water and sand is inertial with respect to rapid movements: in response to a sudden movement, it seems to harden.

For the formation of quicksand, water must move from bottom to top - which provides a tide or underground flow. In the Sahara Desert, quicksand is formed in the area of ​​​​the existence of a large underground river, which people did not know about until the beginning of the era of probing the structure of the earth's surface from a satellite. Sometimes, the cause of such a zone may be an earthquake. 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. Builders of buildings and subways in St. Petersburg often encounter quicksand, where the soils are oversaturated with water. In these places they are called quicksand.

Not only lonely travelers or animals become victims of quicksand. There is a place where the sands swallow up ships: the South Foreland cape in England (Goodwin Shoals) is world famous as the “ship graveyard”. On a long sandbank, there are shipwrecks submerged in the sand. The sands hold the victim tenaciously, and it is almost impossible to save the ship, and sometimes the crew. One day, the ship Gelena Modjeska, whose cargo was estimated at $3 million, fell victim to the Goodwin Sands. For four days, eight rescue tugboats tried to save the ship, but on the fifth day, the Helena Modjeska broke in half, and the cargo and ship perished in the sands. And in 1954, in this place, quicksand sucked in an entire lighthouse that warned ships of danger. The tower went completely into the sand.