Eruptive volcanoes. Volcanic lightning: the nature of origin. The most dangerous volcano in the world
Eruption
Eruption - the process of volcanic eruption on the earth's surface of heated debris, ash, magma outpouring, which, pouring to the surface, becomes lava. A volcanic eruption can have a time period from a few hours to many years.
Volcanic eruptions can lead to large-scale destruction and natural disasters. The main causes of destruction and death of people during eruptions are the following:
- the release of magma, which drains from the slopes of the volcano, destroys buildings and wildlife.
- the release of volcanic ash, which can settle in a dense layer on the areas closest to the volcano and lead to collapse of the roof of houses and power lines. When mixing ash with water, a material similar to concrete is formed, so even in small amounts it can harm people by inhaling ash particles and settling them on the lungs. Also, ash can cause damage to moving parts of mechanical devices, such as aircraft engines.
- the formation of pyroclastic flows consisting of a mixture of volcanic gases, ash and stones formed during the eruption of the volcano. The flow rate sometimes reaches 700 km / h. Pyroclastic flows are one of the main causes of deaths during volcanic eruptions. For example, it is believed that Pompeii was destroyed precisely pyroclastic flow. Sometimes, when a volcano erupts, a lakhar is formed - a mud stream consisting of a mixture of water, volcanic ash, pumice and rocks. Lahar arises when mixing hot incandescent volcanic material with colder waters of crater lakes, rivers, glaciers or rain water. One of the most known eruptions The volcano, which led to the formation of a powerful lakhara, is the eruption of the volcano Nevado del Ruiz in 1985. Mud flows formed a powerful lakhar, which almost completely destroyed the city of Armero. Of the 29,000 residents of the city, more than 20,000 people were killed.
Interculturality and low level of education also make action more difficult. At the same time, we must add poverty to the country, the lack of adequate communication systems and problems of logistics. The weakness of the previous diagnosis of health does not allow us to quickly demonstrate the consequences of a natural disaster or identify health risks, especially the most vulnerable groups of the population, children, the elderly and previous patients.
Baños, a tourist city of thousands of residents, was left empty. Also, the evacuation of all other population groups that were at high risk of both Tungurahua and Chimborazo was ordered. Temporary shelters were adapted in nearby cities, but many people could not do this in trained places and had to stay with their relatives, and the demand for medical care was growing. This city was not prepared for mass migration and in such a short time, so their health systems were quickly saturated, creating a very peculiar social phenomenon, such as people sleeping on sidewalks, the collapse of cleaning systems and garbage collection, provision of food, water and so on. . something similar, but on a smaller scale, was presented in Riobamba, where the a large number of emigrants.
The volcano, which produces the most powerful and voluminous eruptions (8 VEI points) is often called a "super volcano". The main danger of the super volcano lies in the release of a huge ash cloud, which has a catastrophic effect on the global climate and the average temperature for many years. As volcanologists suggest, the last eruption of the super volcano on Earth occurred 27,000 years ago on the North Island of New Zealand, and most severe eruption in the history of mankind was about 73 thousand years ago with the eruption of the super-volcano Toba. Scientists believe that during this eruption more than a thousand cubic kilometers of magma were thrown out of the earth's interior, and the catastrophic consequences of such eruption led to a sharp reduction in the number of different species of living beings, including humans (anthropologists estimated at that time no more than 10,000 people the whole Earth).
The fall of thousands of tons of ash almost daily in the areas surrounding the volcano was not considered high risk, resulting in the fact that about a thousand rural residents from the provinces of Tungurahua and Chimborazo left their homes and land, unable to withstand the irreconcilable conditions in which their families lived. In particular, the health status of these rural residents has not been fully explored. Falling ash and abandoning the land meant a significant impact on agriculture and productive activities of the population.
Despite the established measures and high risks, other residents still cling to their heritage and continue to live in places with serious risks and high air pollution, soil and water. These are rural people with a low social, cultural and economic level.
A TEN OF THE MOST GRANDLY VOLCANOES ON THE EARTH
Already after this article was ready, in April 2010 there was an eruption of the Icelandic volcano Eyyafyatlayokudl, so the list of geological monsters listed below could be somewhat more interesting taking into account this event. Icelandic "snowdrop" erupted twice within one month, melting the ice, releasing huge masses of steam, smoke and ash into the atmosphere, which significantly spoiled the atmosphere and caused thousands of people to suffer inconvenience due to flight delays. In addition, hundreds of residents of Iceland were threatened by floods. Of course, the scale of the volcano Eyyafyatlayokudl is much smaller than any of the below. Nevertheless, the events that occurred in Europe in the spring of 2010, clearly showed how destructive and catastrophic for Europeans could be an eruption, even if this volcano is in Iceland.
The scenario of volcanic eruptions is not uniform, varies with time and even during the same eruption. For this reason, a regular monitoring of the composition of volcanic ash is necessary. One way to learn about the health impact of affected people is to change the epidemiological profile of the population before and during the eruptive processes compared in the same period of the year, that is before and during the fall of the ash.
Source: forms of daily parts of external consultation and emergencies in the health fields of the provinces of Tungurahua and Chimborazo. Data processing and special tabulation. To eliminate the deficit of the baseline, it was decided to review the diagnoses of consultations of all operational units of the affected health areas that were sent to the daily and emergency parts, twelve months before the first eruption, the explosive. In these departments they are especially visited by general practitioners. On October 15, the volcano Tungurahua produced the first ash emissions.
None of the people are able to accurately predict the eruption of the volcano. In ancient times this grandiose natural phenomenon was perceived by the inhabitants of the planet as a divine punishment. Today, however, it is not a secret for anyone exactly what the nature of volcanic processes is. Every schoolboy knows that under our feet we are constantly experiencing a certain displacement of tectonic platforms. Naturally, a situation happens when such a shift releases the output of a red-hot red magma, which comes from the core of the planet to its surface. Now let's move on to the list of the most powerful eruptions in history.
In Table 2, we can observe cases of pathologies associated with the exposure of volcanic ash to the respiratory, skin, eye and gastrointestinal system of the population that lives around the Tungurahua volcano within a radius of 50 kilometers. In the total number of consultations from one period to another is increased by 1, 93 times. On the contrary, the upper and lower respiratory states increased by more than 2, 5 times, conjunctivitis increased by 2, 3 times, tuberculosis increased by 2, 25 times and asthma 2, 1 times, which boasted the influence of ashes on these systems.
With dermatitis, there was an increase of 1, 86, which is similar to the general increase in consultations, so it was not considered final. The increase in upper respiratory tract diseases, decrease and conjunctivitis is consistent with other international studies. The increase in tuberculosis is 2, 25 times, which is consistent with the hypothesis of an increase based on the high prevalence of the disease in this region, subjected to massive contamination with silicone and irritant. Confirmation of this risk and pathophysiological mechanisms is now a necessity.
10. Lamington Volcano
This giant of 1680 meters high is located in Papua New Guinea. Unfortunately, the inhabitants of the local province of Oro mistakenly believed that this is just a mountain covered with dense forest. People learned about their mistake late in the evening on January 18, 1951, when thick smoke started from the top of the mountain and lava began to flow.
Lamington Volcano, 1951
These issues should be demonstrated using data from the Guagua-Pichincha volcano and other future research models. It is expected that the results of provincial and specialized hospitals will be better visible. It was expected that injuries could be increased due to falling ash, indirect effects when cleaning roofs and accidents due to a fall in their own height. This initial processing confirmed the reduction of consultations for these reasons.
The results of this study are similar to those obtained in other studies, but the results, such as the increase in tuberculosis and other diseases that we study, deserve the attention of the scientific community. Subsequent deliveries will further analyze the morbidity and results of monitoring the environment and water.
Three days after the beginning of the events, a powerful explosion occurred on the north side of the volcano, and as a result powerful currents of volcanic products consisting of pumice, sulfuric acid, vapor and magma flew into the air. Over the next few months, the eruption intensively continued, tremors were felt, constant releases of pumice and hot fragments of rock occurred. Products eruptions scattered and spread in a radius of 15 km from the center of the volcano, as a result of the catastrophe killed about three thousand people.
Sarah Serdeira, violating the barriers of space, helped us from Spain to develop a theoretical framework and get a complex bibliography. Eruptions and lahars of Mount Pinatubo, Philippines. Ecological and labor epidemiology. The Pan American Health Organization, the impact of the disaster on health and the approach to care. Q: Scientific publication No. Health management in emergencies after natural disasters.
Infectious diseases and their control after natural disasters. Q: Epidemiology of natural disasters. Ecological impact after a natural catastrophe. Under the volcano: fire, ash and asthma? Respiratory responses to questionnaires: how they change over time. Prevalence of symptoms of asthma and asthma in three cities in France. The influence of volcanoes on health: readiness in Mexico.
9. The Papandayan volcano
This low-activity crater volcano is located on the Indonesian island of Java. In 1772 one of the sides of the volcano exploded and crashed an avalanche of rocks and lava into the surrounding 40 villages, completely destroying them. About three thousand local residents perished.
Volcano Papandayan, 1924
The impact of volcanic ash on health: a re-study. Immediate public health problems and actions in volcanic eruptions: lessons of eruptions on the island of St. Helens, May 18 - October 18. The impact of volcanic ash on the respiratory system.
Observation of public health after a volcanic eruption: lessons from Cerro Negro, Nicaragua. Eye effects after the volcanic eruption of Mount St. Eruption, ie. Magma emissions at more or less regular intervals are the most impressive manifestation of volcanic activity.
The height of the volcano Papandayan is 1,800 meters
Until now, this volcano is regarded as a source of danger, most of the territory around this mountain is closed to all but authorized experts. This measure does not seem superfluous considering that for a long time the volcano is smoky, there are tremors and small eruptions that occurred in 1923 and 1942, and in 2002 there were several of them. It is noteworthy that the capacity of eruptions of the volcano Papandayan from time to time increased.
Active volcanoes are currently in the wild or have been in recent times. They are resting volcanoes that have long been inadequately eroded to be considered harmless, but which give signs of activity due to gaseous emissions. Extinct volcanoes say that for several centuries there were no signs of activity, because their magma chamber no longer fed.
It has an effusive effusion, when magnesium with low content silica is quite liquid and can easily pass through the volcanic canal to the surface, the gases in it gradually disappear, which contributes to a silent effusive eruption, the lava flows from the crater and flows along the slopes of volcanoes, quickly departs.
8. The Volcano of Kelud
Kelud volcano is also located on the island of Java, but on the opposite side of it. . Its height is 1731 meters. The most powerful eruption of Kelud occurred in 1568, when about 10 thousand people died. The last time the Kelut was active in 2008, but a larger eruption of this volcano occurred in 1919, when the flow of lahara (the so-called mud volcanic product consisting of a mixture of water and volcanic ash) surpassed the imaginary and unimaginable expectations .
There is an explosive explosion when a rich silica magma is very viscous and rises with greater difficulty to the surface, the gases contained in it are released violently, overwhelmingly overcoming the resistance of the overlying material: from the top of the crumbling stone rope and lava sprayed into droplets, to the air. Sometimes magma is so viscous that it can not overflow from the crater, but solidifies in it, forming a sort of "cap", a solid material that will sooner or later exert pressure from the gas.
Kelud volcano
On that sinister day, May 19, huge masses of magma burst from the depths of the earth, collapsed on nearby villages and destroyed about 5,000 local residents. After this tragedy, an Ampere tunnel was built, a specific drainage system designed to drain excess liquid from the crater lake, which helps to reduce the flow of lahar during the eruption. The last lava release was noted in 2007, when the highest threat of eruption was declared, and 30,000 local residents had to be evacuated. The main eruption of Kelut volcano occurred two weeks later, when in a radius of 10 kilometers the surrounding villages were covered with a thick layer of ash.
At the end of the phase of more intensive eruptive activity, the phase of emanation takes place, which consists in leaving hot vapors and gases from the crater; This is followed by a phase of rest or calm, during which a "disappearance of activity" occurs, often only seeming.
Large volcanic eruptions are among the most terrible disasters that can have a global impact. Therefore, their prediction is the main task of volcanology. Scientists from the University of Southampton discovered a mechanism on the Canary Island of Tenerife, which may become the key to an early warning of large-scale eruptions.
7. Unzen Volcano
The Unzen Volcano is located in the Kyushu region of Japan and in fact consists of several stratovolcanoes. The height of the volcano is fifteen hundred meters. The Unzen Volcano is still active, but the most large-scale events occurred in 1792, on May 21. Due to a strong earthquake, the old extrusion dome Mayuyama collapsed. (An extrusion dome is formed by the eruption of a volcano with a viscous lava.)
Large cast out volcanic material up to 25 kilometers high, and pyroclastic material was discovered at a distance of up to 130 kilometers from the volcano. Large scientists have studied the caldera by analyzing lavas removed from this volcano at various stages of its activity - in particular, clusters of crystals that are formed in the magma as it cools. They are typical for the magma of that era just before the eruption, when the old magma is mixed in magmatic fire with a fresh influx of luminous material from the depths.
Figure: layers of volcanic material from volcanic eruptions on the slopes of the caldera of Las Canas. Rex Taylor of the University of Southampton learned that they have a great history of stories that preceded catastrophic eruptions. The crystals grew from a variety of magma types and showed that there was intense excitement of the older cold magma with fresh heat.
Unzen, November 18, 1995
6. The volcano of Nevado del Ruiz
Located in Colombia. A notorious fame to this volcano was its powerful lakhara stream, consisting of mudflows and products formed as a result of landslide phenomena. This stream consists mainly of pyroclastic materials and water, all this "infernal mixture" is abundantly poured from the crater during the eruption. (The pyroclastic flow is a mixture of hot gas, ash and stones formed during the eruption.) Naturally, during the activity of the volcano, Nevado del Ruiz seldom manages without destruction and human casualties. Thus, in 1595, red-hot streams of magma and mud fell into the waters of the rivers Guali and Lagunillas, eventually killing 635 people. The next time the catastrophe occurred in 1845, then the number of human casualties exceeded 1,000 people.
More about volcanic disasters can be found in my book "Death Vulcan." If your bookshop does not have it, you can order it here. With the knowledge that we have obtained it will be possible to accurately predict volcanic risk in Tenerife and elsewhere. Any major eruption in the Canary Islands will not only be affected by the local population, but should have a negative economic impact on the entire European Union. After the last a major eruption and the appearance of the caldera on Tenerife, a new volcano appeared - Teide.
Figure: Volcanic bombs in the caldera of Las Canas. In a sense, this is the largest European volcano - despite its geographic affiliation to Africa, the Canary Islands are Spain. Since then, Teide whispered six times. Teide is a dangerous type of volcano, which from time to time weaves deadly clouds of pyroclastic material, slipping down the slopes and destroying everything in its path. That's why he earned a rating among the 16 most dangerous volcanoes on the volcanoes of the Decade. He is still active, as evidenced by fumaroles in the crater at the top.
Nevado del Ruiz
Despite past catastrophic eruptions, on the frozen magma of the volcano Nevado del Ruiz, the city of Armero was built. The extreme carelessness shown by people was confirmed in 1985, when the number of victims of the eruption reached a staggering 23,000 people, which roughly corresponds to the entire population of Armero. The Lahar flow, moving at a speed of 60 km / h, simply buried the city, incidentally causing Colombia economic losses of one billion US dollars.
5. The Montana Pele volcano
The French island of Martinique, located in the Caribbean, is now very popular among those tourists who want to enjoy the exciting views of a very unusual landscape. This landscape arose as a result of a deadly catastrophe that occurred more than two centuries ago, and took the first place in the history of the eruptions of the XX century. Such a sad superiority of the Pele volcano is not surprising, given that the cataclysm killed about 30 000 people.
The eruption of the Mon-Pele volcano in 1902
Events developed gradually. First, in April of the same year, tremors began, the volcano emitted smoke, threw sulfur and ash, and on May 8 there was a large-scale eruption. Fountains of lava, clouds of fire and toxic smoke swept from the earth's interior at a speed of 800 km / h, volcanic products with a temperature of more than a thousand degrees incinerate the nearby city of Saint Pierre, which smoked for several days after the eruption. All the inhabitants of the city were killed, only two of the lucky survived.
4. Krakatoa volcano
Among the possible sources of tectonic disasters, the Krakatau volcano can in no way be regarded as secondary. It is located in Indonesia in the Sunda Sound. In August 1883, several powerful explosions took place, 13,000 times the strength of the atomic bomb explosion in Hiroshima.
Krakatoa volcano
The sound of the disaster could be heard even in Australia, in the city of Perth. In the air, more than 21 cubic kilometers of rock, ash and pumice were thrown out, the cloud of eruption products rose to a height of about a hundred kilometers. According to official data, about 37,000 people died, mostly as a result of the tsunami, although in reality the number of victims appeared to be much larger.
3. The Tambora volcano
The volcano of Tambor is another of the 130 active volcanoes in Indonesia, it is located on the island of Sumbawa, and its height is 4,300 meters. This giant "distinguished itself" in April-June 1815, when the whole globe felt the consequences of its eruption. Volcanic products so polluted the atmosphere that, due to a crop failure in Europe and the United States, there was a raging hunger that was not equal in the 19th century.
Tambora Volcano
During the eruption of freedom, such a large amount of red-hot lava burst out that all nearby villages were completely destroyed. A huge amount of ash fell into the air, as a result of which acid rains fell out, and all vegetation was destroyed on the island. The sad result - 71,000 people were killed by fire, starvation or poisoning.
2. Vesuvius volcano
The second number in the black list is appropriated to this mountain quite justifiably. We can firmly say that the volcano Vesuvius "rightly" is notorious among the inhabitants of Italy, because the list of his victims reaches 25 000 people. During the terrible eruption of this monster, which occurred in 79 AD. e., was completely covered with the nearby town of Pompeii, as well as several nearby villages were destroyed.
Vesuvius, aerial view
The picture of what was happening was, without exaggeration, appalling. The products of the eruption rose in the air in the form of a huge column almost 30 km high, with powerful emissions occurring for 20 hours. Since then, the eruption of this volcano has occurred more than ten times. The last catastrophe occurred in 1944, as a result, several nearby villages were destroyed.
1. Lucky volcano
Lucky is a legendary volcano in Iceland, which has been dormant since its last eruption in 1783. The height of this mountain is relatively small - 1725 meters, but this did not stop him from creating a catastrophic situation, without exaggeration, on a national scale. During this, sad memory, the eruption of the elements in a short time destroyed half of the country's population. People died, breathing in poisoned smoke, consisting of fluorine and sulfur dioxide. In addition, due to the death of plants and animals, famine began, which reduced the remaining population by half. A huge amount of basaltic lava flowed from the earth's interior to the surface, and the fiery fountain hit the height of 1,000 meters.
The consequences of the catastrophe were felt all over the world, and in Great Britain the summer of 1783 was even called the "sandy summer", due to particles of ash and smoke that filled all the airspace over the kingdom. Poisoned clouds spread throughout Europe, and the presence of a huge amount of aerosols in the air led to a catastrophic decrease in temperature in the northern hemisphere of the planet. Only in one UK the following winter from the cold killed more than 8,000 people. In North America, the winter of 1784 was the longest and coldest in the history of meteorological observations. In the state of New Jersey, an absolute record was set for the amount of snow that fell, the Mississippi River froze in the New Orleans area, and the surface of the Gulf of Mexico was covered with ice.
Eruption
Our Earth is not all solidly solid, but rather it resembles an egg: on top is a thin hard shell, under it is a viscous layer of hot mantle, and in the center is a solid core. Earth's "shell" is called the lithosphere, which in Greek means "stone shell". The thickness of the lithosphere averages about 1% of the radius of the globe: on land it is 70-80 kilometers, and in the depths of the oceans there can be only 20 kilometers. The lithosphere is all riddled with rifts and resembles a mosaic.
The temperature of the mantle is thousands of degrees: the temperature is closer to the core, closer to the shell - less. Because of the difference in temperature, the mantle material mixes: hot masses rise upward, and cold ones go down (just like boiling water in a pot or kettle, but it only happens thousands of times slower). The mantle, though heated to great temperatures, but because of the colossal pressure in the center of the Earth, it is not liquid, but viscous - like a very dense resin. The lithosphere-the "shell" as it were floating in a viscous mantle, a little immersed in it under the weight of its weight.
Reaching the base of the lithosphere, the cooling mass of the mantle moves horizontally along a hard rock "shell" for a while, but then, once cooled, it again descends toward the center of the earth. As long as the mantle moves along the lithosphere, pieces of "shell" (lithospheric plates) are involuntarily moving along with it, while parts of the stone mosaic collide and creep one upon another.
Part of the plate, which was on the bottom (on which the other slab crawled), gradually plunges into the mantle and begins to melt. So magma is formed - a dense mass of molten rocks with gases and water vapor. Magma is lighter than surrounding rocks, so it slowly rises to the surface and accumulates in so-called magmatic foci, which are located most often along the line of collision of plates. Magma is more liquid than mantle, but still thick enough; in translation from Greek, "magma" means "thick paste" or "dough".
The behavior of the hot magma in the igneous foci and truth resembles a yeast dough: magma increases in volume, occupies all free space and rises from the depths of the earth through cracks, striving to break free. As the dough lifts the lid of the pan and flows over the edge, so does magma break through the earth's crust in the weakest places and break free to the surface. This is the volcanic eruption.
The eruption of the volcano is due to the degassing of the magma. The process of degassing is known to everyone: if you gently open a bottle of carbonated drink (lemonade, coca-cola, kvass or champagne), cotton is heard, and smoke appears from the bottle, and sometimes foam - it comes out of the drink (ie, it degasses ). If a bottle of champagne before shaking is opened or heated, then a powerful jet will escape from it, and it is impossible to keep this process. And if the bottle is not tightly closed, then this jet can itself knock out the cork from the bottle.
Magma in the magma chamber is under pressure, as well as carbonated drinks in a closed bottle. In the place where the earth's crust was "loosely closed", magma can escape from the depths of the earth, knocking out the "cork" of the volcano, and the stronger the "cork", the stronger will be the eruption of the volcano. Rising up, the magma loses gases and vapors of water and turns into lava - a magma depleted of gases. In contrast to effervescent drinks, the gases that are released during the eruption of the volcano are combustible, so they ignite and explode in the volcano's vent. The strength of the volcano explosion is so powerful that the huge "funnel" (caldera) remains after the eruption after the eruption, and if the eruption continues, a new volcano begins to grow right in this hollow.
However, it happens that the magma can find an easy way out to the surface of the Earth, then the lava flows from volcanoes without explosions at all - like boiling porridge, gurgling, pouring over the edge of the pan (for example, volcanoes in the Hawaiian Islands erupt). The magma does not always have enough strength to reach the surface, and then it slowly solidifies at a depth. In this case, the volcano is not formed at all.
How does the volcano work? When the "valve" opens in the Earth (the volcano plug is knocked out), the pressure in the upper part of the magma chamber decreases sharply; below, where the pressure is still large, the dissolved gases are still included in the magma. In the mouth of the volcano from the magma, bubbles of gases are already beginning to emerge: the higher, the more they become; these light "balloons" go up and carry with them a viscous magma. Near the surface is already formed a continuous foamy mass (frozen volcanic stone foam is even lighter than water - this is known to all pumice stone). Degassing of magma ends on the surface, where, breaking free, it turns into lava, ash, hot gases, vapors of water and debris of rocks.
After a tumultuous process of degassing, the pressure in the magma chamber decreases, and the eruption of the volcano ceases. The crater of the volcano is closed by a frozen lava, but sometimes it is not very strong: in the igneous focus there is enough heat, therefore volcanic gases (fumaroles) or streams of boiling water (geysers) can burst through the cracks. In this case, the volcano is still considered active. At any time, a large amount of magma can accumulate in the magma chamber, and then the eruption process will begin again.
There are cases when volcanoes erupted, which were silent for 300, 500, 800 years. Volcanoes, which at least once erupted in the memory of a person (and can earn again), are called sleeping.
Extinct (or ancient) volcanoes are those that worked in the distant geological past. For example, the capital of Scotland, the city of Edinburgh, stands on ancient volcano, which erupted more than 300 million years ago (then there were no dinosaurs either).
Let's sum up the results
As a result of the movement of lithospheric plates, magmatic foci may appear. If the liquid magma breaks to the surface of the Earth, an eruption of the volcano begins. Often the eruption of the volcano is accompanied by powerful explosions, this is due to the degassing of magma and the explosion of combustible gases. The volcano falls asleep if the supply of new portions of magma from the magma chamber stops, but it can wake up (alive) if the plates move on and the magma chamber is refilled. Volcanoes will fade completely, if the movement of plates in this area ceases.
The eruption of the volcano is an active activity of the volcano, dangerous for all forms of life, throwing out on the earth's surface incandescent fragments, ash, outpouring of lava. The eruption of the volcano can last from several hours to many years. During explosive eruptions a large amount of detrital material is thrown out: volcanic bombs (from pea to 2-3 meters in size), ash. As a result, the release of ash at a high altitude into the atmosphere affects the Earth's weather for a long time. At some eruptions, viscous magma freezes in the crater of the volcano, without pouring out.
The volcano emits gases, liquid and solid substances with a high temperature. This often causes the destruction of buildings and deaths. Lava and other red-hot eruptive substances flow down the slopes of the mountain and burn out everything they meet on their way, bringing innumerable sacrifices and staggering material losses. The only protection against volcanoes is a general evacuation, therefore the population must necessarily be familiar with the evacuation plan and unquestioningly obey the authorities if necessary.
In 1883, in August in Indonesia, on the island of Krakatoa (800 m high), one of the most famous and powerful volcanic eruptions occurred, the echoes of this event were heard even for 3,500 km. in Australia, and a year after the eruption the sky was adorned with extraordinary, colorful divorces. Spilled 18 cu. km of lava, and a huge wave, 35 meters, swept hundreds of coastal towns and cities of Java and Sumatra, resulting in the death of 36,000 people.
There are about 600 active volcanoes on Earth. The highest of them are in Ecuador (Cotopaxi - 5896 and Sangay - 5410 meters) and in Mexico (Popocatepetl - 5452 meters). In Russia there is the fourth highest volcano in the world - this is Klyuchevskaya Sopka height of 4750 meters. One catastrophic eruption occurred on May 8, 1902 on the island of Martinique in the Caribbean Sea. The day before, the Soufriere Volcano woke up on a neighboring island, killing 2,000 people. Residents of the town of Saint-Pierre on Martinique did not hear in this threat to themselves - only two thousand people were evacuated. And in the morning of the next day three explosions brought down the incandescent lava and ash to the town. The city completely burned down, 30 thousand people died.
In the history of catastrophes, one more terrible eruption takes place - Vesuvius. August 24, 79 on the Neopolitan Bay there was an explosion that buried three cities under a layer of ash, lava and boiling mud: Pompeii, Herculaneum and Stabia. On that day, 10 thousand people died.
Almost all manifestations of volcanic activity are dangerous. Of course, the danger of boiling lava or bombs. But no less terrible is ashes, which penetrate literally everywhere. Imagine a continuous gray-black snowfall that floods streets and ponds, doors of houses. Roofs, crumbling under its weight. Pompeii died exactly like this: under a layer of ash at 7-8 meters.
The volcano is dangerous not only during the eruption. Crater boiling sulfur can remain for a long time under an externally strong crust. Dangerous and acidic or alkaline gases, which resemble fog. However, even ordinary carbon dioxide kills all life.
The valley of death in Kamchatka (in the Valley of Geysers) accumulates carbon dioxide, which is heavier than air, and wolves, foxes, hares or birds often die in this lowland. It is interesting that a person can go through such a trap without even noticing - if it turns out to be above the layer of heavy gas.
Modern science quite accurately predicts volcanic eruptions. Almost on each active volcano there are stations or devices that allow you to monitor the life of the fiery mountain. The usual solution to the threat of a catastrophe is the evacuation of neighboring towns and cities. However, sometimes it is possible to argue with the elements. For example, in 1983 on the slope of the famous Etna it was possible to create a directed channel for lava by explosions, which saved the nearest villages from the threat.
As a consoling example, we can cite the history of the struggle of the inhabitants of the Icelandic town of Weistmannaeyar with their volcano, which arose on January 23, 1973. About two hundred men left after the evacuation, sent firefighters on the lava crawling to the port. Cooling off from the water, the lava was stone. Powerful jets of sea water from the dredger, which entered the port, joined the fight. Then pipelines were installed, it was possible to save most of the city, the port, and no one was hurt. True, the struggle with the volcano dragged on for almost six months.
Here are the steps to take when you do not need evacuation:
do not panic, stay at home, shutting doors and windows;
if someone needs help, then leave the house, putting on warm clothes, preferably non-flammable, protecting the nose and mouth with a moistened cloth;
do not hide in basements so as not to be buried under a layer of dirt;
do not use the car;
do not call, but get information on the radio;
stock up on water;
to ensure that the fall of hot stones does not cause fires, which should be immediately extinguished, at the first opportunity - to clean the roof of the ash;
invite experts to test the stability of the building.
British scientists believe that humanity can die as a result of a giant volcanic eruption. According to Stephen Self of the Open University of Great Britain in an interview with the electronic magazine LiveScience, there is no way to prevent a catastrophe. Geophysicists claim that some volcanoes are capable of eruptions hundreds of times more powerful than those observed ever. Cataclysms of this magnitude, however, have already occurred on Earth - long before the emergence of civilization. Previously, American geologists discovered a relatively shallow layer of volcanic ash in the Yellowstone National Park. The culprit of his appearance is considered the eruption of exceptional strength, which happened about 620 thousand years ago. Monument to this event is a giant funnel - caldera, which formed after the destruction of "devastated" volcanoes. The consequences of the giant eruption are described in detail in the report submitted to the working group on natural disasters under the British government. Large enough territories are buried beneath a layer of lava, and dust and ash released into the atmosphere make it difficult for the sun to access the earth's surface, which affects the global climate. As Michael Rampino of the University of New York showed in his study, the "overthrow" of the Toba volcano on the island of Sumatra, which occurred 74 thousand years ago, led to a significant cooling and death of three quarters of the flora of the Northern Hemisphere.
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How to create animated movies
Illustrations to the text - the working material of the new animated film "Riddle of the Desert" studio TouchFX. The project has not been announced anywhere, ...
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What should I do if a spider bites a spider?
The cross is obliged to the original color, which makes it possible to see an improvised cross on his belly. Despite the menacing appearance, he is very ...