What is quicksand and how to survive in it. Attention, quicksand! How sand is sucked up near the coast Where does quicksand come from?
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Quicksand is a deadly "attraction". The main danger is that they are virtually indistinguishable from ordinary sandy areas. This means that if you are traveling, for example, in the desert, where there is often a landscape of the same type without stones and vegetation, then there is a possibility that at some point you will simply start to sink into the ground.
Quicksand: what is it
Basically, quicksand is formed in places where underground sources appear or when groundwater approaches the soil. In addition, the condition for their appearance is the presence of sand without clay impurities with a grain diameter of up to 3 mm.
The smallest particles of moisture, mixing with such sand, do not allow air to pass through, and friction between the grains of sand disappears. As a result, grains of sand turn into a semi-liquid mass, a swamp, which outwardly is almost impossible to distinguish from an ordinary desert or beach. It is a viscous mass with tremendous resistance.
How to spot quicksand
It is difficult to visually detect classic quicksands - they can trap the traveler anywhere along the way. There is a road that takes more than one day, gradually attentiveness dulls, which leads to dire consequences.
Since quicksand is a viscous bog, outwardly it looks like a flat surface with small stationary ripple waves. That is, any flat area could potentially turn out to be impenetrable swamp. It should be noted that sand on the surface of the bog can dry out and sometimes even grass grows on it.
Most often, quicksand can be found along the shores of water bodies and in the lowlands of hills - where underground sources are likely to reach the surface. To be on the safe side, you need to move slowly, be able to quickly get rid of the backpack and other cargo, as well as probe the way in front of you with a pole or stick.
In its normal, dry state, when poured from vessel to vessel (take an hourglass as an example), sand lets air through. But in the presence of moisture, air does not pass between the grains of sand, and the sand does not spill out, clogging the passage. This property is the basis for the appearance of the bog.
Such a sandy one is characterized by a tremendous resistance force. If a person's leg falls into quicksand, to release it, it is necessary to expend the effort of a heavyweight weightlifter, and then provided that his other leg has a reliable point of support and is on a solid surface.
In addition, the impact of a bog can be compared to a seat belt - the sharper the trapped person moves, the more firmly they are bound by the swamp. This is due to the instant "hardening" of quicksand due to the appearance of rarefied air under the released leg. The presence of a discharged space leads to the opposite effect - to tighten the leg even deeper ("collapse").
Quicksand against man
At its core, quicksand can be classified as a type of non-Newtonian fluid with a high content of fine solids (grains of sand). That is why a person, getting into such a place, begins to fall into it, like into water. If at the same time he does not make sudden movements, then the dive will stop when the mass of the displaced sand becomes equal to the mass of a person.
What to do if caught in quicksand
There are certain rules of conduct when entering quicksand. Following these rules will allow you to get out of the situation alive.
1. Don't panic! You start to twitch or make other sharp movements - you will go towards the core of the planet.
2. Fall on your back, flat, preferably on your back - in general, take a horizontal position with your whole body.
3. Try to immediately throw off all unnecessary things - backpack, tent, etc. Life is more important.
You start to make sudden movements - pits will appear, which will continue to be sucked. After the excitement calms down, move slowly, preferably back, in the direction from which you came, since it is not known how far forward the dangerous sands extend.
Relax your body, imagine that you are lying on your back in the water and relaxing. When moving, the sand should flow gently under the body and to the sides. This is a laborious but effective process. If your lower body does enter the sand vertically, place your torso on a surface and slowly but with effort gradually release your legs.
Interesting and tragic facts about quicksand
Morekembe Bay, England. It has been known since the 15th century, when it was forbidden to walk on the sand at high tide. Annually killed up to 150 people. People caught in the quicksand died during the 9-meter high tide, which covered them with their heads.
The Goodwin Shoals at South Foreland, England. Swallowing ships whose remains rise above the sands. The place is known as the "Ship Graveyard". One day the Goodwin shoals swallowed up the lighthouse tower.
Tarnegen Fjord, Alaska. The coast is about 80 km long and consists of quicksand.
Sable Island, Atlantic. Quicksands consume entire ships after shipwrecks.
Jamaica, the city of Port Royal. Completely drowned in quicksand in 1692. 2,000 citizens died. After the earthquake, the soil hardened, so it was initially believed that the city was swallowed up by the "deep sea".
An example of American paratroopers falling into the quicksand
\u003e wildlife survival\u003e coastal quicksand
Why coastal quicksand is dangerous
Coastal quicksands are found on the shores of lakes, rivers, seas, where rising springs are often found. On top of the quicksand there may be a thin crust of silt formed from the fine sand fraction. 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. 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 with water is formed, the properties of which differ significantly from a mixture of sand, water and air.
The main condition for the formation of coastal quicksand is a large source of water, which is located at a depth of several meters, and sometimes several tens of meters. Such sources also provoke shedding of sand. In most cases, they try to escape with great force, rising as close to the surface as possible and enveloping individual grains of sand with water. Thus, a loose sandy mass saturated with water is formed, which remains in equilibrium for some time. When any object gets here, the structure collapses, and physical forces try to return the displaced sand back. Suction occurs. Naturally, not every source can become the basis for the formation of quicksand. Only a source that moves in an inclined horizontal direction or almost vertically becomes the culprit for the formation of the coastal "trap".
It is sometimes impossible to determine the location of such sand. From above, it looks quite reliable and there is no doubt that it is possible to move on this surface. Grass and flowers can grow here, however, if such a sandy formation is found in a rocky area, it is better to bypass it. It is simply impossible to check whether a nearby water source provoked the appearance of quicksand.
The danger of coastal sands is possibly even greater than that of a swamp. When you walk through the swamp, you always understand the situation and realize where you are. And coastal sand looks no different from an ordinary beach, but at the same time it can become deadly.
How to get out of coastal quicksand
Falling and killing people in quicksand is not uncommon. 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 opposition, 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 element only if you move very smoothly, or even better, try to lie on your back or stomach, freeing your legs, and try to "swim" on the sand in the direction you came from. If you can't move forward, don't make sudden movements, call for help. Get rid of unnecessary things and clothes if possible. If there is a person nearby who can help you, even if he does not get too close, he will have to reach you with a rope, stick or other object, which you will need to hold on tightly and climb slowly but surely. Without additional support, it is almost impossible to get out on your own. When you try to pull out, for example, a leg, a vacuum is formed and a huge force arises, pulling the leg back. The effort required to lift a leg can reach several hundred kilograms.
It should be said right away that the widespread opinion that quicksand can pull a person headlong is an exaggeration. However, they are really dangerous because it is very difficult to free yourself without assistance. Trapped in the sand, people died from dehydration, sunburn, drowned during high tides, because they did not have time to save them in time.
How quicksand is formed
It is absolutely impossible to simply determine by eye that the place in front of you is mortally dangerous. The sun dries up the top layer of sand, sometimes even some vegetation appears on it. One gets the impression that this is the most ordinary sand. As a matter of fact, the way it is - ordinary, only very fine, like dust.
The main reason for 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 unevenness of their surfaces. If the sand is moistened, the adhesive forces will increase many times over. The water covers the grains of sand with a thin film, the forces of the surface tension of which make them 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, surface tension forces cease to act. A fluid and viscous water-sand mixture is formed. As a matter of 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 quicksand "drags on"
Sand becomes quick-moving if there is a fairly powerful underground source under it. The stream of water moving upwards, as it were, "whips up" the sandy surface above it. The mutual arrangement of grains of sand becomes unstable, but nevertheless 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 failed person. The structure of the sand mass changes. Now the grains of sand are tightly pressed to each other, and the surface tension forces of the water film form a reinforced concrete frame around his legs. Since there is no air between the grains of sand, a rarefied space is formed with any movement. Wet sand, which has a high viscosity, does not have time to fill the cavities formed during the movement, and the force of atmospheric pressure tends to return the shifting body back. The impression is that the sand is addictive.
Scientists believe that another reason for the formation of quicksand is static charges, resulting from the friction of sand grains. Since they are all of the same name, the grip between the grains of sand is weakened.
Nature is fraught with many dangers. Unfortunately, we sometimes underestimate these dangers. And this neglect leads to tragedy. There are places in nature where it is extremely dangerous to be. Such hazardous areas include quicksand.
What are they? It is a sandy surface with increased mobility. Any object or living thing caught in the quicksand can be pulled inward. The tightening speed is uneven: it can happen in a matter of minutes or over many months. Different peoples have legends and myths associated with quicksand. The insidiousness of quicksand is that outwardly they seem quite safe. In English folklore, there are many legends about quicksand, since there are many such dangerous zones.
This is not to say that people did not try to fight the quicksand. In the 19th century, quicksand was diligently destroyed in England, filling them with stones, sand and gravel. Therefore, now there is practically no danger of meeting them in those places where people live. However, in some places, quicksand still awaits its victims. Surprisingly, there is still no clear explanation for this phenomenon.
There are various hypotheses, certainly interesting. The Russian physicist V. Frolov believes that the phenomenon of quicksand is based on electrical effects, due to which friction between the grains of sand decreases and the sand becomes viscous and fluid. Viscosity can spread to a depth of several meters, the soil becomes unstable and sucks in any object or living thing. There is an assumption that the main reason that the sand sucks in various objects is in the form of individual grains of sand. All of them are of the correct spherical shape. That is why any heavy object sinks so easily, passing "through" them.
American scientist J. Clark has studied the quicksand phenomenon for a long time. He believes that these sands are mixed with water, therefore they acquired the properties of a liquid medium. Clarke suggests that the ripple is a special state of sand. It can manifest itself in different places if there is exposure to water. For example, if the surface is regularly flooded with water at high tide, or there is an underground river under the surface.
In England, not far from Morkembe Bay, there is a place called Arnside. There are regular hot flashes. At low tide, the water recedes several kilometers, revealing the bottom of the bay. If you step on sand, which seems to be very stable, you can immediately be pulled downward. It is impossible to escape on your own, so many die.
A very beautiful place, the Tarnegen Fjord in Alaska, is also dangerous. It is also not recommended to be there during low tide. Many people know about the island called Sable. It is located in the Atlantic Ocean 180 kilometers from the coast. There are many reefs in its vicinity, which are often the cause of shipwrecks. The remains of the wrecked ships on the shore are covered with sand.
There are many quicksands not only in Alaska, but also in the Sahara. It is known that in the desert whole caravans can go into the sand. Scientists have found that there is an underground river under the Sahara, which is perhaps why the surface is becoming so treacherous.
Quicksand is not just dangerous for an individual person or animal. An entire city can go underground. This is exactly what happened in 1692 on. An entire area of \u200b\u200bthe city of Port Royal was sucked into the quicksand. The city was located on a sandy surface, which is why the tragedy happened. On June 7, 1692, an earthquake struck. Historical chronicles tell how some residents of the city immediately fell into the ground, others were sucked up to the knee or to the waist. The earthquake lasted for several minutes. Then the sand immediately turned into a solid mass that held people captive. Many died. In the 19th century, on the site of the lost city, the remains of the walls of the collapsed houses were still visible, and in 1907, after another earthquake, everything went underground.
Fjord - Tornagan is an interesting place in Alaska. In 1988. the car of two passers-by got stuck in the sand. Adreanna Dixon got out of her car and fell into the sand with her foot. Her husband tried to pull her out, but her leg got stuck as if in concrete. Compressed, the sand held the woman, which led to her death, as the tide began. Adreanna drowned.
The reason for her death was not only water, but the quicksand was to blame. It sucks in any object and does not let go, like a big trap.
The rate at which quicksand sucks in something depends on many factors, including the structure of the sand, its mass, the volume of the object, and can last from a couple of minutes to a month.
Many scary stories and legends have been created with this natural phenomenon. The adequate part of the stories shows the real danger when colliding with muddy sand. But in 2000, a film was released, which is embellished to such an extent that a person does not want to sunbathe on an ordinary beach.
The main part of the legends appeared in Great Britain, where there were many dangerous areas of sucking animals and people on the sea coasts.
In the 19th century, most of the territories with quicksand were destroyed, now there is no danger on the comfortable beaches.
Scientists have not fully studied the nature of this formidable phenomenon. There is a theory that all this may be due to the special texture of the grains of sand. Russian physicist Frolov put forward a hypothesis that there is a special mechanism in which sand changes and has a liquid structure. And its "fluidity" goes into a depth of a couple of meters, and from this the soil turns into a viscous absorbing something and absorbs any object caught in it, pulling it down.
American geologist Clark spent many years researching this phenomenon and came to the conclusion that the ripple is the state of sand. And if an underground river flows under the sand, then the direction of the water can naturally change and go into the depths. Then, the stream of water rises and the surface of the earth becomes a dangerous threat.
It is impossible even to roughly calculate the number of victims from quicksand, it is more likely to exceed tens of thousands of people. Once, deadly sand destroyed an entire area of \u200b\u200bthe city in Jamaica, then more than 2,000 people died, since the city was densely populated. Also, there is a place where the sand absorbs ships. And in the same England, Cape South Foreland is widely known as the "ship graveyard". The steamer, whose cargo was estimated at $ 3 million, broke in half, for five days the rescuers tried to do something, but all was in vain. You should not underestimate the sand, because in the same place, in 1954, a huge lighthouse went underground.
