People have great ideas about the Dead Sea! A common myth is that people don't drown in the Dead Sea. But in reality, drowning happens, and certainly not in the usual way in the Dead Sea that it does in normal waters. Here are the reasons why people can float on the waters of the Dead Sea.
In fact, the Dead Sea is not an ocean, but a lake spread over a vast area. It straddles the border between Israel and Joden. The Dead Sea is also a tourist attraction. It is the lowest valley on Earth. The water present in the Dead Sea has higher solubility of salts and many minerals. The salinity of the Dead Sea is said to cure many diseases. Especially people with skin problems can visit this place as part of their treatment. We can see resorts and medical facilities on the seaside. Visitors can swim as they don't have to worry about sharks or dangerous sea animals. Yes, swimming is recommended with a high level of safety. You may be wondering how people will float in the water of the Dead Sea and as I said, will they drown? The salinity of seawater is the reason behind this. The salt concentration in the Dead Sea is 10 times higher than in any other sea.
The more salts and minerals dissolved in water, the higher the density. Since objects displace an amount of water equal to their weight, they do not sink. In concentrated salt water, most of the body floats on the surface of the water because even a small amount of displaced volume creates enough buoyancy to support the weight of the human body. The body floating on the water looks like a cork. Therefore, swimming in the Dead Sea generally does not cause drowning.
However, there are occasional cases of drowning. While floating, this may pose a hazard if the person flips over instead of on their back. Based on past experience, if the back is up and the face is facing the water, in this case we think of pushing ourselves out of the water with our feet. If this happened in the Dead Sea, it would be impossible. Because the water here is very deep, our feet cannot touch the ground. People can easily choke and swallow this highly salty water, which can lead to an electrolytic imbalance. Ingesting large amounts of salt can damage the heart and kidneys, and eventually, people who choke on water will become poisoned. In this case, a person will drown. Therefore, resorts and medical facilities near the Dead Sea always insist that customers wear life jackets while coming into contact with the Dead Sea.
The density of Dead Sea Water is about 1.23 Kg/L, while the density of ordinary seawater is about 1.027Kg/L, and the density of fresh drinking water is 1.0Kg/L. The Dead Sea has a salinity of 33.7%, while any other seawater has a salinity of about 3.5%, and fresh drinking water has a salinity of 0.1%.
The water of the Dead Sea contains high concentrations of minerals such as magnesium, potassium, sulfur, calcium and bromide.
There are a total of 21 minerals in the Dead Sea, 12 of which cannot be found in other waters.
High concentrations of minerals help treat skin problems such as skin allergies, atopic dermatitis, wrinkles, hair loss, psoriasis, etc. People there use Dead Sea sand to treat arthritis because the minerals in the sand help increase blood circulation and also act as a muscle relaxant. Although the high concentration of minerals in the Dead Sea has cured many diseases, ironically the stagnant water cannot support life due to its high salt concentration.
The Dead Sea is located at the border of Israel, Palestine and Jordan. It is the lowest lake in the world, with an altitude of -430.5 meters. The deepest point of the lake is 380.29 meters, and the altitude of the deepest lake bed is -800.112 meters. The salt content in the Dead Sea is extremely high, and it gets higher as you get to the bottom of the lake. It is 10 times more salty than the ordinary ocean. The lake water in the deepest part has been fossilized (general seawater has a salt content of 3.5%, while the salt content of the Dead Sea is 23% to 25%. The salt content in the surface water reaches 227 to 275 grams per liter, and the salt content in the deep water reaches 327 grams).
Due to the high concentration of salt water, the density of water is greater than that of humans. The specific gravity of water in the Dead Sea is 1.17~1.227, while the specific gravity of the human body is only 1.02~1.097. Swimming like this It is easy to float, but this also means that no living things can survive in the water. Even on the land along the coast of the Dead Sea, there are very few living things except aquatic plants. This is one of the reasons why people named it the Dead Sea.
So why does the Dead Sea contain such a high concentration of salt?
The Dead Sea topography was formed during plate movement. It is an extension of the East African Rift Valley in Asia Minor, and is surrounded by high mountains that block the flow of the Mediterranean Sea. It is a The sinking crust. Therefore, the Dead Sea has become an inland lake under such terrain. It is located in the Jordan Valley between Israel, Palestine, and Jordan. The west bank is the Judean Mountains, and the east bank is the Transjordan Plateau. The Jordan River enters from the north. The Jordan River injects 540 million cubic meters of water into the Dead Sea every year, and there are four other small but perennial rivers that inject water from the east.
The Dead Sea is located in a desert. Although it has a Mediterranean climate, the rainfall is very rare and irregular. The average annual rainfall is only 50 mm. It belongs to the desert belt of Western Asia. The average temperature in summer can reach 34C°, with the highest temperature reaching 51C°, and the temperature in winter can also reach 14~17C°. The higher the temperature, the greater the evaporation. The annual evaporation of the lake water averages 1,400 mm, so dense fog often forms on the lake surface. The water level of the lake changes seasonally, between 30 and 60 centimeters. There are many sunny days, strong sunshine, and little rain. The amount of supplementary water is minimal. This climate causes almost all the water from the Jordan River to flow into the Dead Sea (40-65 centimeters per day). billion liters) all dried up, leaving even more salt behind. As a result, over the years, more and more minerals have settled on the bottom of the lake, making it more and more salty. It is estimated that the total salt content of the Dead Sea is approximately 13 billion tons.
The Dead Sea is a large salt storage place. The salt is mainly found in the Sedom Mountains on the southwest coast. Mount Sedom is located at the southwest end of the Dead Sea, 170 meters lower than sea level. The mountain is almost entirely made of salt, covered only by a thin layer of rock. Every winter, rainwater seeps into the cracks in the rocks, dissolves salt, and constantly forms new caves. Salt has been mined here in small quantities since ancient times.
Due to the terrain, the salt from Mount Sedom is also injected into the Dead Sea, exacerbating the salt content in the Dead Sea. In addition, there are environmental problems in the Dead Sea.
Because the Dead Sea is surrounded by land and is not connected to other rivers and oceans, there is no tidal phenomenon in the Dead Sea. The Dead Sea, a saltwater lake on the border between Israel and Jordan, is disappearing. According to relevant data from the World Environmental Protection Organization, the level of the Dead Sea is declining at a rate of 3.3 feet (about 1 meter) per year. With the decreasing water volume, the salt concentration of the Dead Sea has greatly increased.
In fact, in addition to the Dead Sea, Lake Don Juan in Antarctica and Gaet'ale Pond in Ethiopia are both more salty than the Dead Sea. Gaet'ale Pond is crescent-shaped, about 60 meters in diameter, and has a water salinity exceeding 43%, the pond was created after the earthquake in January 2005.
Lake Don Juan is a saltwater lake discovered in Antarctica in 1961. The shallowest part of the water in Tang Juan Lake only reaches a person's ankle. The water has a high salinity of 40%. The salt content of each liter of lake water can reach more than 270 grams. This is because the ions generated by the salt ionization move in the water molecules and prevent ice cubes. The formation of a crystal network structure lowers the freezing point of the pool water, which also causes it to never freeze even if it is located in the frozen Antarctic.
However, neither of these two lakes has the same ornamental and tourism value as the Dead Sea. So it is not as famous as the Dead Sea.
Answer: The Dead Sea is the third saltiest water body in the world. It has an extremely high salt content, which makes the water in the Dead Sea denser than the average density of the human body. So the human body can float in it.
The Dead Sea is located at the junction of three countries and is the northern extension of the East African Rift Valley. It is the lowest lake in the world, with an altitude of about -430 meters above sea level and a minimum altitude of -800 meters at the bottom of the lake. 67 kilometers, 18 kilometers wide, and the lake area is 810 square kilometers.
The Dead Sea is not a "sea", but a lake. To be precise, it is an inland lake, and it is in a desert. Only a few surrounding rivers flow into the Dead Sea. In addition, rainfall is very low all year round and evaporation in summer It is also very large, causing a large amount of salt to accumulate in the Dead Sea, and the water level of the Dead Sea is lowering every year.
The density of water in the Dead Sea is as high as 1.25~1.29g/cm^3, which is slightly higher than the average density of the human body (about 1.02/cm^3).
It is precisely because the density is higher than that of the human body that people can easily float on the lake. A simple calculation shows:
The average density of the human body: the density of the Dead Sea ≈0.8
So when a person is floating in the Dead Sea, about 20% of the body's volume can be exposed to the lake. The human head accounts for about 7% to 10% of the body's volume, which is enough to extend the entire head out of the lake. The density of freshwater lakes is close to 1g/cm^3, which is slightly lower than that of humans. Therefore, when people drown in freshwater lakes, they will tend to sink to the bottom.
In the Dead Sea, the salt content changes with the water depth. The deeper the water, the higher the salt content. Even at the bottom of the lake, the salts have crystallized into solids. At this time, some of the salts are close to saturated solutions. .
Using chemical knowledge, we know that the solubility of a saturated sodium chloride solution at 20°C is 36.0g (100 grams of water can dissolve 36 grams of sodium chloride solid), which translates into a salt content of 26.5%.
In the Dead Sea, salts include not only sodium chloride, but also potassium salts, calcium salts, magnesium salts, etc. Calculated as a whole, the salt content of the Dead Sea is as high as 23~30%, which is equivalent to 100% salt per liter. It contains about 250 grams of salt, while the average salt content of the four oceans is 3.5%, only one-eighth of the Dead Sea.
Although the Dead Sea has a very high salt content, it can only rank third among water bodies in the world. The first two water bodies are:
1 Gaet'ale Pond in Ethiopia has a salt content of 43%, mainly calcium chloride and magnesium chloride, but is only about 60 meters in diameter. It was formed in an earthquake in 2005.
2. Don Juan Pool in Antarctica has a salt content of 40% and a diameter of about 300 meters.
Since the first two are much smaller in area, which is equivalent to the level of a pond, it is no problem for us to call the Dead Sea the lake with the highest salt content. .
The salt content in the Dead Sea is enough to kill most aquatic organisms, which is also the origin of the name of the Dead Sea; for example, during the flood season, the water flowing from the Jordan River into the Dead Sea will have an influx of fish and shrimp, and these organisms will enter the Dead Sea. Afterwards, they will quickly die from dehydration and lack of oxygen.
The proteins of most organisms will dehydrate in high-concentration salt water and then lose their activity. Only a very small number of microorganisms and algae can survive in it; for example, there is a type of halophilic bacteria, so The protein it contains can not dehydrate in a high-salt environment, and can only remain active in a high-salt environment, so the Dead Sea has become a "paradise" for this type of halophilic bacteria.
The Dead Sea Floating refers to the Dead Sea located between Israel, Palestine and Jordan. It is a famous health resort in the world. It's called the Dead Sea, but it never drowns anyone. Because the water contains a large proportion of Dead Sea salt, even if people cannot swim, they can lie on their backs on the water, leisurely bathe in the sun, and enjoy floating with the waves. At this time, the muscles of the body no longer resist gravity, and quickly enter a state of complete relaxation. The sense of weight also disappears, and the consciousness enters a state of nothingness. All worries can be forgotten, and the body and mind can get an excellent rest.
In the SPA trend that has become popular in the past two years, the mineral mud and mineral salts from the Dead Sea are of the highest quality because they are rich in minerals and trace elements. Especially in modern society, facing the heavy pressure of society, family, and work, people's physical and mental load imbalances and the accumulation of toxins seriously affect the balance of various human systems. The use of mineral mud and mineral salts from the Dead Sea, combined with Plant essential oils and herbs are used for whole-body detoxification, which can eliminate intercellular toxins, promote blood and lymph circulation, stimulate and regenerate functional cells throughout the body, and allow the body and mind to be detoxified, repaired, enjoyed, and revived.
It is rich in minerals and trace elements and can be used as a mud compress on the face and body. In addition to making the skin extremely smooth, soft and white, it can also treat dermatitis, arthritis, etc. Because of its medical value, European national insurance plans also cover Dead Sea treatments.
Water is rich in more than 40 minerals and trace elements such as sodium, potassium, calcium, bromine, and iodine. It has significant effects on rheumatoid arthritis, skin diseases, obesity, cardiovascular and cerebrovascular diseases, respiratory diseases, etc. According to relevant UNESCO research data, people can achieve the effect of eight hours of sleep by floating in the Dead Sea for one hour.
When I was a child, there was an article in my textbook called "The Dead Sea Never Dies." It talked about why the Dead Sea cannot drown people because it has high salt content and high buoyancy, so people cannot sink at all.
So the question is, if people can’t drown, why are there so many lifeguards on the Dead Sea in Israel?
I have had an infinite yearning for the Dead Sea since I was a child. I want to experience rafting on the Dead Sea for myself. Either I have a classic photo or I am lying on the water reading a magazine. You can lie down on the water however you want. The buoyancy of the Dead Sea is very strong, and people do float on it, but it is not that easy to stabilize it. Floating swimming is very different from swimming in ordinary water, and the water in the Dead Sea is extremely salty. The water splashed into the corners of the eyes, and the eyes immediately hurt like crazy. I just wanted to wipe the water off my eyes with my hands, but there was no trace of water on my eyes. It's all salt water.
The Dead Sea is located between Israel, Jordan and Palestine. There is not a single fish in it, which may be the origin of its name.
The Dead Sea is a famous health resort. People can easily lie down on the sea. As for the reason, it involves the floating and sinking conditions of the object: for an object immersed in a liquid, if the buoyant force is less than the object's gravity, the object will sink (all the way to the bottom); if the buoyant force is equal to the object's gravity, the object will float; if the buoyant force is greater than Due to the gravity of the object, the object floats up (eventually floats on the liquid surface). For a homogeneous solid object, if the density of the object is greater than the density of the liquid, the object sinks; if the density of the object is equal to the density of the liquid, the object floats; if the density of the object is less than the density of the liquid, the object floats.
The average density of the human body is slightly greater than the density of water (1.0×10?kg/m?), and it will sink freely in water. However, if the gas is inhaled, the average density of the human body will be slightly smaller than the density of water, so people can float in the water without moving.
Those who have swum in seawater know that it is easier for people to float in seawater because seawater contains a lot of salt and its density (1.03×10?kg/m?) is greater than that of fresh water. , the buoyancy force experienced by a human body immersed in sea water is greater than that experienced by fresh water.
In the Dead Sea, the density of seawater is higher, up to 1.18×10?kg/m?, which is denser than ordinary salt water. As long as more than half of the human body is immersed in seawater, the buoyancy force it receives is equal to the human body. gravity. It takes some effort for a person to sink into the sea water. Even if he dives into the sea water, he will be lifted out by the sea water. People can lie on the sea water, read books and newspapers leisurely, and receive the nourishment of the sea water.
Because the salt content is high, the density of water will be high. The high density of water will cause the buoyancy force on people to be greater than their own gravity, and they will float.
If a person wants to float in the water, it actually requires that the buoyancy force on the person is greater than the gravity on the person.
The buoyancy formula is as follows:
F=ρgv
g is a constant, v is the volume of water displaced by a person, these two items are basically unchanged. ρ is the liquid density.
Basically, the density of the liquid > the density of the human body: float; conversely, the density of the human body > the density of the liquid, sink. If the two are equal, a floating effect of neither going up nor down can be achieved.
So generally speaking, if you hold your breath and relax your body while swimming, you can actually float. Seawater is denser than freshwater, so it floats more easily in seawater. The water density of the Dead Sea is much greater than that of sea water, so it is easier for people to float when they enter it.
Of course, in this case, it is okay to lie down in the sun and read a book, but it becomes difficult to swim.
The salt concentration of general seawater is about 3.5%. The salt content of the Dead Sea is about 23% to 25%, which is almost 7 or 8 times that of ordinary seawater. Moreover, the water level of the Dead Sea changes every year. As the water volume decreases, the salt concentration becomes even higher.
According to some data, the total salt content of the Dead Sea is about 13 billion tons. There is some difference in salt concentration between deep water and surface water. The concentration of deep water is more, 327g per liter, and the surface water is about 227~275g.
1 liter is 1 liter. Think about the feeling of filling a 1-liter mineral water bottle with water and pouring half a bag of salt into it~
One of the reasons why the Dead Sea is called this is because the salt concentration in the lake water is too high. Except for a small amount of microorganisms, ordinary fish, shrimps, and aquatic plants cannot survive.
I remember after some calculations, if you have a 400L bathtub, then you can basically have a low-end version of the Dead Sea by adding 240 packs of 500g salt to it~
The density of human and ordinary water is close, so humans can learn to swim (float on water) through training.
However, the water in the Dead Sea is extremely salty, and fish and shrimp cannot survive. The high salt content causes the density of the lake water to increase. When the density of the lake water When the density is higher than the human body, people will float on the water.
Just like oil floating on water. (But not all oil is less dense than water)
The Dead Sea has a high salt content, so its density is much higher than that of ordinary water, and the density of people In fact, it is close to the density of water, so it is easier for people to float in the Dead Sea.
But whether it can float depends on the person itself. People who can swim can float even in ordinary swimming pools. We see those elegant people reading books and drinking wine in the Dead Sea. In fact, they are all people with some swimming skills. Ordinary people who cannot swim will find it difficult to float even if they go to the Dead Sea.
For example: If you lie on your side, it will definitely be heavy. Because of this, people actually drown in the Dead Sea every year.
According to statistics, 21 people drowned in 2010; 31 people in 2009 and 44 people in 2008. 22 people in 2017.
First of all, the Dead Sea contains a lot of salt. The large amount of salt causes the density of the Dead Sea to be very high, which is much higher than the density of the human body. This directly causes the buoyancy force we experience to be greater than gravity, so we will not sink. . The Dead Sea also contains a lot of minerals. The water continues to evaporate and the minerals precipitate. Over the years, it has become the saltiest saltwater lake today.
So why does this happen? 1: The temperature in the Dead Sea area is very high. The average summer temperature is as high as 51°. You must know that the highest temperature in Chongqing is only 42°. Africans even complain that they can't stand it. It’s also 14-17° in winter. The higher the temperature, the greater the evaporation. 2: It is dry and rainless here. The average annual rainfall is only 50 mm, while the evaporation is about 140 mm. Such many sunny days, strong sunshine, and few rainy days have resulted in more and more minerals accumulating, and the saltiness also increasing. Three: The Dead Sea is an endorheic lake. The only way for water to escape is evaporation. The Jordan River is the only river that flows into the Dead Sea. The amount of water injected is negligible compared to the amount of evaporation in the Dead Sea. In addition, in recent years, the riverside residents The water level in the Dead Sea is declining year by year due to the withdrawal of water to irrigate crops.
The salt content in the Dead Sea is relatively thick and is greater than the density of the human body, so it can float.