Why lightning strikes houses. What to do during a thunderstorm
Due to the fact that a lightning strike is not useful for humans, you and I must protect ourselves as much as possible from being hit by it. more prone to accidental contact with lightning than city running, especially if we're talking about about the hills and mountains where you are the highest point of the landscape.
How lightning appears
The main role in the formation of lightning is played by photoionization and high-energy cosmic particles, which create a shower of charged particles in the atmosphere. Both mechanisms lead to a branched discharge form, often with side channels of varying power with an average speed of the order of 200 km/s.
Near the surface of the earth (water), under the influence of the electric field of lightning, a counter discharge is emitted from some point, which merges with the main one at a height of about 30-50 m (lightning orientation height). The main discharge occurs through the formed ionized channel. Usually lightning consists of 2-3 repeated discharges, sometimes there can be dozens of them. The total duration of lightning reaches 0.2 - 1 s.
It is important to understand that the arrival of a lightning strike to the surface of the earth at the orientation height is a random event that cannot be influenced. You can only influence the location of the release of the oncoming streamer by installing a high lightning rod for this.
Despite the high probability, a lightning strike may not necessarily fall on the highest point created by man specifically for this purpose. There are often cases of it hitting, for example, a power line support closer to the ground, bypassing the lightning conductor wire at the very top.
How often does lightning strike a person?
You should not be guided by statistics that say that lightning strikes a person extremely rarely. Because in most cases, statistics do not take into account too many factors and only take into account the total number of people and the total number of thunderstorms.
In fact, if you consider the number of lightning strikes in nature, during trails, cycling, hiking and running, and not in cities, among skyscrapers and radio antennas, then the percentage of the probability of a strike increases significantly. Several times.
It should be taken into account that cases of lightning striking a person are not always recorded if the outcome was not fatal. And it is fatal in 20% of cases, according to published data. Unfortunately, not everyone who is lucky enough to survive can return to a full life due to various injuries in nervous system or in the musculoskeletal system.
However, runners are occasionally struck by lightning, after which they are able to not only survive, but also continue the race to the finish line. Ultramarathoners and cyclists are, of course, more likely than other athletes to encounter lightning. For them, the routes are long, including in terms of time, and can pass through completely different weather and terrain conditions.
Be that as it may, the absence of damage to the body after an encounter with lightning is an exception, so we should still know the basics of safety when caught in a thunderstorm.
Rules of behavior in a thunderstorm
1. Most safe place during a thunderstorm it is a building. It doesn’t matter whether it’s a house or a store, but if you have the opportunity to wait out the passage of a thunderstorm front directly above you, you should take advantage of it. A car is also a suitable option, which in fact is a Faraday cage if the body is made of aluminum. However, in all cases, contact with metal surfaces and lines, such as fittings, wiring, and radiators, must be avoided.
2. Don't be the tallest object on the ground, because in this case you can play the role of a lightning rod. Although it all depends on the soil under you and its heterogeneity. The same applies to other free-standing objects - which is why it is not recommended to hide under the only tree in a field. Lightning will pass through the shortest route to the ground through a tree, which can simply explode with a strong discharge and, in addition, slightly concuss you.
Wood has a fairly large inductive resistance, and if it is also highly curved, then we can expect the formation of additional ionized channels with lower resistance next to it. The human body is great for this.
3. Even in a dense forest, you need to wisely choose a place to wait out the bad weather. The tallest trees here are natural lightning rod. The safest option is to locate under the dense canopy of the shortest trees or shrubs.
4. If a thunderstorm finds you in an open field, then best option- this is to sit down as much as possible closer to the ground in the fetal position on the driest ground and wait it out. It may be wet and uncomfortable, but it is the safest.
5. Conductive materials During a thunderstorm, they become bad friends, including your carbon trekking poles or your aluminum or carbon fiber bike. Especially if you wave them over your head. This equally applies to any accumulations of metal near you, be it poles, pipes, wires or fences. During thunderstorms, stay at least 30 meters away from them.
We have listed the basic rules for behavior in a thunderstorm, but there are also other recommendations, some of which are still controversial and do not have convincing evidence. But they are easy to implement, so do not neglect them.
These include using mobile communications and lighting a fire: cases of lightning strikes while communicating on a mobile phone have been recorded. As well as lightning strikes into fires and chimneys due to the high conductivity of smoke.
It is worth remembering that rubber running shoe sole in the case of lightning it does not work and does not pose any obstacle to it. If the path is the shortest, and soil conductivity conditions are favorable for the formation of an oncoming streamer at “ preparatory stage» lightning formation, then the discharge will pierce any such insulator. This is not for you to tinker with rubber boots in your home electrical panel.
Where does lightning strike most often?
As a rule, a lightning discharge travels along the path with the highest electrical conductivity. On land in places with more electrically conductive soil, even those in lowlands. This is explained not by the easier passage of the main discharge (it will make its way through any insulator) but by the lighter currents that pull up charges of the opposite sign and the creation of streamers.
In the city, lightning most often, for obvious reasons, hits lightning rods. And also in the highest grounded structures, such as television towers and radio towers. However, in nature, everything is not always so simple, although the principle of the highest objects remains in most cases.
There is a connection between the type of tree and its susceptibility to lightning strikes. Most often, lightning strikes oaks, poplars, and elms. It rarely gets into spruce, pine, fir - they contain a lot of oils, so they have high electrical resistance. Very rarely - in birches and maples.
Always added to the electrical properties of the trees themselves is the influence of the composition of the soil on which they grow: sandy and rocky areas safer than clay.
Safety cone
This term is used when a man-made lightning rod (more precisely, a lightning rod) is used to protect what is located underneath it. The reliable protection zone (no more than 30 m in height) is limited by a cone directed downward from the top of the lightning rod with an angle from the vertical of 30°. Sometimes you can find erroneous information about 45°, but this is outdated data.
Ball lightning
Research physicists believe that when a guest such as ball lightning appears, the worst option is to run and move in any way. This is associated with the appearance of air vortices that can attract a bunch of energy directly to their source, that is, to you.
The theory is not without inaccuracies and it is not entirely clear how this may manifest itself, depending on the distance. There is no confirmed data on this yet either, but it’s better to keep this in mind and save it when we see ball lightning calmness. Fortunately, 80% of cases of ball lightning explosions do not have serious consequences for the observer.
But what you definitely shouldn’t do when meeting her is trying to touch her, drive her away with something, or otherwise make contact. This usually ends in an explosion near the contactor.
Study weather conditions
Before training, especially if it will take place far from populated areas with reliable shelter, it is better to study the weather forecast from different sources. It is better, like pilots, to update the weather report every half hour.
We should only be interested in the possibility of thunderstorm formation in the forecast, since we can continue training in the rain without any problems. Or at least safe to return home under it. But In the event of a thunderstorm, you should not run or ride a bike, because in this way we seriously increase the likelihood of being injured by a discharge.
Distance to thunderstorm
Among other things, you need to know when a storm front is approaching you and when it begins to move away. This is very easy to understand if you time the time from the flash to the sound wave. Its contraction means that a thunderstorm is approaching, and its increase means it is moving away. And knowing the speed of sound, which travels approximately 1 km in 3 seconds, you can easily calculate the distance to the epicenter.
But when the epicenter of a thunderstorm moves away from you and after the rain stops, you shouldn’t immediately run out into the open and do a workout. The likelihood of being struck by lightning remains even after a front has clearly passed over you and blue sky. The same applies to the time before a thunderstorm. At least 30 minutes before and after a thunderstorm It is necessary to exercise the same caution as in the midst of bad weather.
First aid for lightning strikes
If there is a person next to you who has been struck by lightning, do not be afraid to touch him - no charge remains in the victim’s body. You must give him first aid immediately.
The main cause of death from a lightning strike is disruption of the heart and lungs. Therefore, the victim should undergo artificial respiration and cardiac massage.
Deaths from lightning strikes. Scientists are investigating the causes and conditions of their occurrence, developing tactics of behavior during a thunderstorm. However, lightning statistics still record a high degree of injury and mortality from electrical discharges.
How a discharge is formed
Lightning is a powerful discharge of electricity that is usually formed during a thunderstorm, accompanied by thunder and manifests itself as a bright flash. The power of lightning reaches from 10 to 500 thousand amperes, and the voltage ranges from 10 million to 1 billion volts. Such a discharge causes serious harm, even death of the victim. Lightning statistics informs about 2000 thunderstorm events occurring every day around the world.
The nature of lightning is cloud vapor from water that cools and solidifies into ice crystals. Air currents lift small pieces of ice upward and collide them with larger formations that tend to settle below. The collision process is accompanied by the release of electrical discharges - from small elements “+”, and from large pieces of ice “-”. When there is a large accumulation, an area with increased level ion concentrations.
When the difference between charged particles becomes large, a lightning strike occurs in the cloud. Increased concentration of ions occurs in cumulus or stratus rain clouds, during eruptions, tornadoes) and desert storms.
A variety of natural elements
Lightning statistics describe several different strikes, which are distinguished by how they strike and where they strike. Known types of lightning:
- Linear. The rumble on the sky looks like an upside-down tree with a main channel and short branches. The discharge length is at least 20 km. The impact force is about 20 thousand amperes. The discharge speed reaches 148–150 km/h.
- Pearl. It is a continuation of the linear discharge. However, such lightning in the sky looks like precious beads located at a certain distance from each other. Such manifestations are extremely rare. There are no statistics on deaths from discharges of this type.
- Lightning inside a cloud. Discharges are accompanied by changes in magnetic and electric fields and radio wave radiation. Can such lightning strike an airplane? Yes, if it is electrified. If a discharge hits the board, it may occur. Such discharges are usually found closer to the equator.
- Lightning on the ground. The discharge is formed in several stages. Lightning statistics show that the main reason for their formation is the rapid ionization of air. The particles pick up speed due to the action of the electric field and collide with air currents, creating streamers - avalanches of electrons. They form a thermally insulated discharge that reaches the surface, bypassing various obstacles at a speed of 50 thousand km/sec. After completing the entire path, the discharge light dims. The second stage consists of repeating the trajectory. The final discharge will be the brightest and strongest. The electrical formation channel has a temperature of 25 thousand degrees. The consequences of a lightning strike are very destructive due to its duration.
- Ball lightning. She dangerous due to its unpredictability. What does ball lightning look like? Some say it is white or yellow, even bright green, while others say it has a black tint. It appears due to a large accumulation of energy in the cloud and may be a continuation of the initial electrical discharge. Death statistics There is no investigation against ball lightning in Russia.
- Lightning sprite. It was opened at the end of the 80s. It varies in height from 50 to 128 km and in diameter up to 100 km. A flash of electrical discharge looks like a column of light located vertically. Often appears in a group and is red in color.
If the color of the electrical discharges is different, then the smell of lightning is the same. There is a sulfur and ozone aroma in the air.
Why does lightning flash? Due to the high voltage between the ions, a mini explosion occurs. As a result, the discharge is illuminated from the inside.
What are the statistics of lightning striking a person? Every year, data on injuries to 240 thousand people is received.
Manifestation methods
The formation of a discharge is always accompanied by a sound effect. Lightning without thunder physically cannot exist. Sometimes in nature you can observe lightning - when a thundercloud is at a great distance from the ground and the sound simply does not reach.
Lightning strike statistics reports that the probability of human injury is 1: 600 thousand.
Degree of damage
There are four degrees of severity:
- Average. It manifests itself as short-term convulsions, with respiratory and cardiac disturbances, but without loss of consciousness. If lightning strikes a person, deep burns and muscle tears remain on his body.
- Heavy. Manifested by strong convulsive contractions, loss of consciousness, impaired cardiac and respiratory function.
- Very heavy. Manifested by loss of consciousness and requiring cardiopulmonary resuscitation.
- Instant death.
The statistics of deaths from lightning strikes is disappointing. According to the National Weather Service, men died in 80% of cases. Most cases involve people being on the water while a thunderstorm was raging.
Can lightning strike a person hiding under a tree? Yes, trees attract electricity.
Actions in an emergency
What to do if a person is struck by lightning? It is necessary to call an ambulance and perform cardiopulmonary resuscitation. Later, doctors will carry out a set of rescue measures. If necessary, they will intubate the trachea, provide an oxygen mask, administer intravenous sedatives (diazepam, morphine or ketamine), and apply a bandage to the burns.
Are there any known cases of human survival? Statistics on lightning strikes to humans recorded an American ranger who survived seven direct hits.
No one still knows why lightning strikes a person. If the discharge hits the head, the person dies immediately. After damage to other parts of the body, strangely shaped scars usually remain.
Lightning in Russia recorded instant deaths of people who used mobile phones during a thunderstorm. According to unofficial data, about 550 people die annually in Russia.
Doesn't hit the same place twice
A beautiful natural phenomenon can be dangerous not only in open space, but also in a residential building. When there is thunder and lightning outside, it's time to think about your own safety.
Can lightning strike through a window? If it's closed, it can't. Entry into the house occurs through electrical communications and ventilation openings. Sometimes a small draft is enough for ball lightning to fly into the house. It is impossible to predict how she will behave.
What to do in case of lightning? You must not approach her or turn your back. If possible, you need to move away from the flight path. It is also prohibited to throw any objects at it.
The best protection against lightning is sheltering in place with little contact with the ground. It is advisable to use insulating materials such as stone, tent or backpack. We need to get away from trees and tall metal structures. You should install a lightning rod on your home and do not use household appliances during a thunderstorm.
Thunderstorms have always frightened people. And it’s not just the roar that Thor’s chariot or the angry Zeus made. The very powerful electrical discharges that appear in the sky often carry mortal danger. People have made many assumptions about how to behave during a thunderstorm and what properties lightning has. Unfortunately, scientists have proven that many of them turned out to be myths.
Myth 1: Lightning never strikes the same place twice.
Perhaps the most common myth, which, however, is not confirmed by practice. Lightning can strike any number of times in any place. One of the most striking evidence is the Empire State Building in Manhattan. The skyscraper was once used as a lightning laboratory due to its ability to attract electricity. A building is struck by lightning anywhere from 25 to 100 times a year, and sometimes several times per storm.
Photo: GREGORY KRAMER/GETTY IMAGES
By the way, tall buildings can generate lightning themselves. During a thunderstorm, objects on the ground have an electrical charge opposite to that in the cloud. While most lightning strikes from cloud to ground, occasionally it can strike upward from tall buildings and antennas when electrical charges in clouds change rapidly.
Myth 2: Lightning is only dangerous when it rains
Usually people begin to seek shelter from lightning when the first drops of rain from a thundercloud fall on them. However, lightning can strike the ground well beyond the thunderstorm.
Typically this distance is 5 km. However, there are facts when lightning appeared literally like thunder from a clear sky, while the nearest thundercloud was at a distance of 40, and sometimes even up to 80 km.
Myth 3: Headphones make you an ideal lightning target.
“Don't use gadgets during a thunderstorm! They attract lightning,” how many times have we heard this warning. But the facts say otherwise. The same example of the Empire State Building proves that lightning is attracted to objects that are located very high. Therefore, if you are less than 30 meters above the ground, headphones will not increase your chances of being targeted by lightning.
Quite the contrary: a headphone cable can help you divert electrical discharge from your heart. But this will not save you from major burns, so you should not be on the roofs of high-rise buildings during a thunderstorm, even with headphones.
Myth 4: You are absolutely protected at home
Of course, your home is your fortress, but even there you need to beware of lightning. Ideally, during a thunderstorm, you should be as far away from windows and doors as possible. One more good idea- turn off electrical appliances and landline phones. You can easily live without a computer, TV or hairdryer for a couple of hours.
Photo: ADRIAN ASSALVE/GETTY IMAGES
By the way, indoor plumbing and metal window and door frames are effective lightning rods that can increase safety during a thunderstorm. It’s better not to use the shower at this time.
Myth 5: If a person is struck by lightning, he will shock you.
If you saw someone being struck by lightning, then it is quite natural to assume that it is dangerous to touch the person: suddenly an electric charge will also pass through you. In fact, this is not the case, and the lightning victim human body does not store electricity.
Photo: PARAMOUNT PICTURES/FOTOS INTERNATIONAL/GETTY IMAGES
So you can safely provide first aid! Although a lightning strike can cause cardiac arrest, burns and nerve damage, most victims can survive if they receive the necessary medical care.
Myth 6: If you're caught outside in a thunderstorm, it's safer to lie down on the ground.
We already know that during a thunderstorm, the higher it is, the more dangerous it is. The logical conclusion from this would be the decision to lie down on the ground and stretch out on it - how much lower? Especially if it happens in an open field. But it's not that simple.
When lightning strikes the ground in an open area, it can send an electrical current up to 30 meters across the surface. And if you lie on the ground, electricity can strike your entire body.
Therefore, experts advise another option: squat down, bending your head to your knees, and cover your ears with your palms. In this case, you are simultaneously as low as possible to the ground, but touch the ground itself minimally. However, it is worth remembering that this is a last resort method to protect yourself from lightning if there is no normal shelter nearby.
Myth 7: Your car's rubber tires can protect you.
Speaking of shelters. A car can actually be a convenient place to wait out a thunderstorm (though a house is still better). But safety inside the cabin is ensured by the closedness of the car: you won’t get wet in it. But rubber tires, which supposedly can save you from electric discharge, are completely useless.
The same thing, by the way, applies to rubber soles of shoes. Rubber, of course, can protect against electricity. But this does not apply to a layer of a couple of centimeters on car tires or even less on sneakers.
Based on HowStuffWorks.com
A thunderstorm is an interesting natural phenomenon. But everyone knows that there is another side to the coin. A thunderstorm is not only beautiful lightning in the sky, but also danger. The sky covered with dark blue clouds, strong wind, thunder, flashes - everything that we are used to observing in this phenomenon. Many people have probably wondered more than once: “Where does the fiery guest go during a thunderstorm?” You will find out the answer to this question later, but for now you need to figure out how this happens.
Where does the flash come from?
Lightning is a natural phenomenon that is accompanied by a huge spark.
It does not appear as close as we think. Everyone knows that the speed of light is a million times faster than the speed of sound. That is why we first see a flash, and only then hear a roar. How does it appear? Clouds that herald a thunderstorm form in the atmosphere. When the air heats up too much, charged particles converge in one place and burst into flames. This is how lightning occurs. At the same time, it has a very high temperature.
Direction of lightning
We are all accustomed to seeing lightning strike from top to bottom. The channel through which lightning passes is a branching, since the ionization of the air occurs unevenly. Lightning, passing through this channel, also branches, so we are used to seeing the flash not in the form of a straight line, but similar to veins. The main channel through which lightning travels is called the leader. The branches formed from it go in the direction of movement of the leader. It is important to note that a leader cannot suddenly reverse his direction. Current flows through the leader and its branches once it has connected to ground. Passing through the channels, the current hits the direction several times. Thanks to this, we see that lightning flickers.
Where does lightning strike?
Tension in the higher layers is always greater than in the lower ones. Therefore, you can notice that the “heavenly guest” strikes from top to bottom. If you compare lightning to a tree, it will resemble its root system.
Sometimes it happens that the current flows in the opposite direction, that is, from bottom to top. If we compare it with a tree, the leader and its branches will resemble a spreading crown. When lightning strikes from top to bottom, it appears as if it is striking from the sky to the ground. In the second case, we do not perceive that lightning strikes from the ground. Why is this so? It's all about our perception. Lightning is a fast process. Our eyes fixate on it as a whole, but we cannot observe the direction of movement of the current, and human perception is far from objective. Human eyes cannot capture thousands of frames per second. Therefore, we perceive the whole picture.
If you look at a video camera that is capable of capturing these lightning-fast frames, you can see both ascending and descending current flows. How this process occurs is clear, but where does lightning strike? We'll look into this below.
Where does lightning strike and why?
Lightning strikes in those places where the layer between any object and a thundercloud is the smallest. Many objects on the ground that conduct current well attract lightning. Where does lightning strike? It can get into a variety of places: trees, metal towers, poles, pipes, houses, buildings, airplanes, water, even a person. The higher the attraction of an object, the greater the likelihood of a lightning strike. For example, take two pillars standing next to each other: wooden and metal. Most likely the blow will be on the second one.
The fact is that metal objects conduct current much better. After the impact, the current from the ground will flow much more easily to the mast, since it is well connected to the ground. The larger the surface of a metal structure connected to the ground, the greater the likelihood of a lightning strike. Often it hits a flat surface. But there will be a section where there is the greatest conductivity of the surface of the electric current.
For example, swamps are more likely to be struck by lightning than dry sand. Objects in the sky may also be affected. There are known cases when lightning struck an airplane. It does not pose a serious danger to people in the aircraft, but it is quite capable of disabling the equipment. Lightning poses a great danger to people who are indoors during a thunderstorm. It would seem, why is this so, because a person is protected? However, the TV not turned off, working mobile phone, can easily attract current, which is dangerous for humans.
There are known cases when it struck a person on the street. Lightning strikes men more often than women. In rural areas it can hit anywhere. Where does lightning strike in the city? As mentioned, it hits objects that easily conduct current and are well connected to the ground. These will be tall buildings, towers. Fortunately, lightning rods have been invented that are widely used in big cities. For humans, lightning is a dangerous phenomenon. That is why you should follow all safety rules and know how to behave correctly during a thunderstorm.
Myth and nothing more
Information about where lightning strikes most often has become clearer. Now I would like to dispel the myth that lightning does not strike the same place twice. Beats. Lightning can strike the same object several times.