Research project “Volcanoes. Studying deep processes under the Tolbachik will make it possible to more accurately predict volcanic eruptions

Nikolai Shapiro, Doctor of Geological and Mineralogical Sciences, leading researcher at the Institute of Physics of the Earth (Paris) and the Institute of Volcanology and Seismology, Far Eastern Branch of the Russian Academy of Sciences, Professor of the Russian Academy of Sciences
Evgeniy Gordeev, Doctor of Physical and Mathematical Sciences, Director of the Institute of Volcanology and Seismology, Far Eastern Branch of the Russian Academy of Sciences, Academician of the Russian Academy of Sciences
Danila Chebrov, Candidate of Physical and Mathematical Sciences, Director of the Kamchatka Branch of the Unified Geophysical Service of the Russian Academy of Sciences
"Kommersant Science" No. 5, July 2017

Unique observations of deep low-frequency earthquakes obtained by Russian scientists in Kamchatka allow us to trace magmatic processes in the lower layers of the earth's crust. Computer processing of seismic records that preceded the major eruption of the Tolbachik volcano will clarify the patterns of volcanic activity and will make it possible to more reliably predict eruptions.

The main practical goal of volcanology is the development of methods for monitoring volcanic activity in order to timely and reliably predict eruptions. There are more than 1,500 volcanoes on Earth that have erupted at least once over the past 10 thousand years, of which about 600 have erupted in historical times. Every year there are from 50 to 70 eruptions.

Most of the active volcanoes are located in the so-called subduction zones of the Pacific Ring of Fire, where oceanic lithosphere subsides into the mantle. At depths between 100 and 200 km, the interaction of the sinking ocean lithosphere and the mantle produces magmatic melts, which then rise to the Earth's surface and lead to volcanism.

Slow and fast volcanic processes

The main force driving magma to the surface is the difference in density between the relatively “cold” and heavy rocks of the mantle and crust and the heated, fluid-containing and relatively light magmatic melts. Moreover, along most of the path to the surface, magmatic melts do not rise directly, but seep through the porous medium. Therefore, the speed of their rise depends on the porous properties of the mantle and crust and on the viscosity of the magma itself. The chemical composition and physical properties (density, viscosity) of magmatic melts as they rise can change significantly due to interaction with surrounding rocks and due to changing pressure and temperature. The density and porosity of surrounding rocks also change with depth.

Most of the active volcanoes are located in the so-called subduction zones of the Pacific Ring of Fire, where oceanic lithosphere subsides into the mantle

As a result, the process of magma rising to the surface is heterogeneous. Overall this is happening very slowly. Individual volcanic systems can develop over thousands or even millions of years. During this time, magma gradually accumulates in intermediate chambers, the closest of which are located at a depth of several kilometers. But this process is very nonlinear, and certain stages of it can occur very quickly, leading to sharp local accelerations of magma movement and sharp pressure surges. Such accelerations can be caused by sudden changes in physicochemical properties (phase transitions), which, among other things, often lead to the release of a gas fraction in the magma. The activation of such processes can begin from several days to several years before the eruption.

Methods for studying volcanoes

The main difficulty in studying volcanoes is that the geological processes leading to eruptions occur at great depths. Scientists obtain a significant amount of information about the origin and history of volcanoes using geological methods - through the study of igneous volcanic rocks, as well as extinct volcanic systems, the deep parts of which come to the surface after the weathering of the rock.

But when studying the current state of volcanoes and identifying the preparation of eruptions, geophysical observations become the main source of information about deep processes. The leading geophysical method is seismological monitoring. Its main idea is that many deep processes occurring in volcanic systems can generate seismic waves. To observe them, seismographs are installed near volcanoes - instruments that record vibrations of the Earth's surface.

Volcanic earthquakes

Seismic manifestations of deep volcanic activity, or so-called volcanic earthquakes, are numerous and varied. Among them, two main types can be distinguished.

The first type is called volcano-tectonic earthquakes because their properties and origin are similar to ordinary tectonic earthquakes. The activation of volcanoes is primarily associated with an increase in pressure in magma chambers and the acceleration of the rise of magma to the surface. These processes increase mechanical stress in the earth's crust under volcanoes, with the subsequent activation of numerous microfaults, which generate volcano-tectonic earthquakes.

The second type of volcanic earthquakes is generated directly in magma supply channels. With the accelerated movement of magma or volcanic gases through these channels, sharp pressure surges often occur, accompanied by seismic waves. The main characteristic of such sources is that they emit waves at relatively low frequencies - in the range from 1 to 5 hertz. Typical frequencies of waves characteristic of volcano-tectonic earthquakes are 10 hertz or more.

The overwhelming majority of volcanic earthquakes are very weak and are not felt on the surface. But they are well recorded by sensitive seismographs

The overwhelming majority of volcanic earthquakes are very weak and are not felt on the surface. But they are well recorded by sensitive seismographs. The appearance of recorded volcanic earthquakes and a progressive increase in their number is the most reliable sign of the activation of volcanic systems. Counting recorded earthquakes is the simplest method of seismic monitoring of volcanoes. And if observation systems of many instruments are placed on volcanoes, volcanologists have the opportunity to determine the location and magnitude (this is an energy characteristic) of volcanic earthquakes, which, in turn, makes it possible to characterize deep-seated volcanic processes in more detail.

In some cases, it is possible to trace the migration of seismic activity from depth to the surface. Such observations are especially valuable when derived from low-frequency earthquakes, as they relate to the propagation of magma in feeder conduits beneath volcanoes. And this movement of magma plays a decisive role in the preparation of an eruption. Using detailed observations of low-frequency earthquakes, it is possible to better understand the processes that control the feeding of volcanoes with magma from depth.

Volcano laboratories

But high-quality observations of the processes described are rarely obtained. Most active volcanoes do not have modern geophysical observation systems, and conversely, many of the well-observed volcanoes are dormant most of the time. Therefore, for the development of geophysical research and monitoring methods, a few volcanoes are very important - natural laboratories that erupt frequently and are studied in detail. Well-known examples of such volcanoes are Kilauea on the Hawaiian Islands, Piton de la Fournaise on the French island of Reunion, Etna and Stromboli in Italy. These volcanoes erupt almost constantly (Kīlauea) or very frequently, and their eruptions are observed in detail by volcanological observatories that support modern geophysical observation systems.

Much of the scientific work aimed at understanding volcanic earthquakes and related deep-seated processes is based on observations obtained precisely in such laboratory volcanoes.

Unique data from Russian volcanoes

Russia is a country with a large number of active volcanoes. Almost all of them are located in the Far East in the Kuril-Kamchatka subduction zone. A special place among Russian and world volcanic systems is occupied by the Klyuchevskaya northern group, where four very active volcanoes are located not far from each other: Klyuchevskaya has been active for several thousand years; Shiveluch - since August 1980 (since the start of the growth of the lava dome in the crater formed during the catastrophic eruption on November 12, 1964); Nameless - from October 22, 1955 (from the moment of awakening after a thousand years of silence); On Tolbachik volcano, large fissure eruptions occurred in 1975–1976 and in 2012–2013. The area also contains 12 weakly active or extinct volcanoes and about 400 smaller volcanic formations.

Systematic observations in this area began with the creation of the Kamchatka volcanological station in the village of Klyuchi in 1935. The first permanently operating seismograph at this station was installed in 1946. Currently, scientific units of the Institute of Volcanology and Seismology (IViS) of the Far Eastern Branch of the Russian Academy of Sciences and the Kamchatka branch of the Federal Research Center “Unified Geophysical Service of the Russian Academy of Sciences” (KF FRC EGS RAS) are conducting observations on the Klyuchevskaya group of volcanoes. They support a network of 18 permanent seismographs.

Since the mid-1990s, seismic information has been converted into digital format and, on this basis, an archive of continuous seismic records has been created for more than 20 years, during which many dozens of eruptions occurred. This set of observations about the seismic activity of volcanoes has no analogues in the world. One of its unique characteristics is the simultaneous observation of very different volcanoes, which makes it possible to establish the relationship between their activities. Another distinctive feature is the large number of low-frequency volcanic earthquakes at great depths, corresponding to the crust-mantle boundary.

Recently, our joint scientific group of IViS and KF FRC EGS RAS, created with the support of the Russian Science Foundation, carried out a detailed analysis of the data obtained. To do this, we carried out intensive computer processing of seismic records for two years preceding the last major eruption of the Tolbachik volcano.

The results found that the activity of deep low-frequency events increased in the two years before the eruption. This corresponded to a gradual activation and increase in pressure in a deep magma chamber, which is located at a depth of approximately 30 km, that is, at the boundary of the earth’s crust and mantle. Maximum seismic activity at depth was reached five months before the eruption. The maximum number of low-frequency earthquakes in near-surface magma chambers was recorded several months later. We interpreted this delay as the time required for magmatic pressure to propagate from a depth of 30 km to the surface. The rather slow spread of pressure can be explained by the fact that in the lower part of the feeding system, magma does not migrate through an open channel (as is often depicted in textbooks and encyclopedias), but seeps through a porous medium.

Seismic observations obtained at the Klyuchevskaya group of volcanoes contain a huge amount of information that has yet to be analyzed and comprehended. For its full use, it is necessary to develop fundamentally new methods for analyzing geophysical data using modern computer technologies, including machine learning. The implementation of such automated methods is becoming increasingly urgent for processing large data streams in geophysical monitoring of volcanoes and earthquakes. The progress of modern methods will make it possible to prevent the intensification of volcanic activity. And preventing eruptions is one of the most important tasks of modern volcanology.

A terrible natural phenomenon - a volcanic eruption - inspires fear and respect for the underground power of the bowels of our planet. However, there are people who are ready to climb into the very mouth of the fiery mountain, study its toxic fumes, ashes and take samples of orange lava and seething molten stones. These are volcanologists, a special caste of geologists. Representatives of this profession are not only inspired by the romantic spirit of long-distance expeditions, but are also famous for their forecasts of large-scale volcanic disasters.

The word “volcano” itself comes from ancient Roman mythology: it was the name of the god of fire and the patron of blacksmithing. The Greeks called him Hephaestus. Yes, according to legend, it was he who gave fire to people, for which he got it from the elder gods. When modern volcanoes “give” fire, hot lava flows from their slopes, columns of black smoke and clouds of ash burst into the sky, and volcanic bombs—huge pieces of rock—fly out of the crater. But the frightening phenomena that force local residents to flee and seek salvation only attract volcanologists.

Judge for yourself: to study the structure of our planet, there is no need to drill wells in this place - the Earth itself shows its fiery interior. Dressed in a fireproof silver suit, like a fireman at the source of a disaster, a volcanologist carefully approaches the lava flow with a special ladle, or even looks into the crater, lowering a probe there to take samples of molten rocks.

What do such samples give scientists? People have long noticed that at the point of contact of hot lava with cold surface rocks, accumulations of mineral ore are formed - deposits of iron, copper, zinc and other metals. Studying the composition of lava allows us to imagine the conditions on our planet during its formation, billions of years ago! Volcanologists also study extinct and destroyed ancient volcanoes - the accumulation of such knowledge is very important for geology. It helps to piece together a picture of eruptions of past and present years and predict future cataclysms.

The beginning of a comprehensive scientific study of the “fire mountains” is considered to be the opening in 1842 of a special institution - a volcanological observatory, which was built in Italy on the slope of the notorious Vesuvius volcano.

It is Vesuvius, the only active volcano in continental Europe, that is considered one of the most dangerous. More than 80 of its eruptions are documented, the most famous of which occurred on August 24, 79, when three ancient Roman cities were destroyed: Pompeii (completely covered with volcanic ash), Herculaneum (destroyed by a mudslide) and Stabia (flooded with lava). The last eruption of Mount Vesuvius occurred in 1944: one of the lava flows destroyed the cities of Massa and San Sebastiano, killing 57 people.

Nowadays, the situation in the vicinity of this mountain is constantly monitored. At the beginning of the 20th century, interest in volcanoes flared up throughout the world: in 1911, an observatory was created on the Kilauea volcano in the Hawaiian Islands, and then observatories appeared in Indonesia and Japan. Soon the entire Pacific “ring of fire” was covered by observation.

In our country, there are especially many volcanoes in Kamchatka. Klyuchevskoy, Bezymianny, Sheveluch - they are known to everyone. From time to time, these volcanoes erupt simultaneously, and ash falls more often than snow in their vicinity. In total, there are about 150 volcanoes in Kamchatka, a third of them are active, and people live in the vicinity of many of them.

The record holder for the number of fire-breathing neighbors is the village of Klyuchi; not far from it there are five active volcanoes, not counting the extinct ones. Here the first volcanic station on the peninsula was built. Nowadays, an entire Institute of Volcanology and Seismology, Far Eastern Branch of the Russian Academy of Sciences, operates in Petropavlovsk-Kamchatsky.

The romance of long-distance expeditions and the danger of eruptions played a cruel joke on the profession of volcanologist. At the beginning of the 20th century, as soon as volcanology became fashionable, a great many amateur “scientists” appeared in the world. As soon as an eruption began somewhere, a local geology teacher (or even just tourists who happened to be nearby) immediately declared themselves “volcanologists.” Of course, for the most part, such “experts” turned out to be harmless - however, there is also a tragic case that occurred due to such impostors from science.

At the beginning of May 1902, several of these “volcanologists” announced that the largest city of the island of Martinique, Saint-Pierre, was not in any danger, and this prevented the reasonably frightened population from evacuating. The threat was more than real, and on May 8 of the same year, the self-proclaimed “experts” burned alive in a cloud of hot ash from the Mont Pele volcano, along with 30 thousand residents of the unfortunate city.

In addition to the reliable prediction of eruptions and the general study of the molten interior of the earth, the profession of a volcanologist also has purely practical aspects. These scientists are participating in the development of methods for using steam and heat from hot springs on the slopes of the fiery mountains - for the needs, as they say, of “industry and everyday life.” And, of course, when an eruption occurs, volcanologists monitor the direction of the ash plume and, according to their forecasts, air traffic controllers adjust aircraft routes. This was the case last spring and summer, when air traffic over Europe was blocked by the Icelandic volcano with the unpronounceable name Eyjafjallajokull.

Volcanologists note that this mountain awoke unnoticed for ten years. Eyjafjallajökull entered its active phase a year ago and exploded on April 14. “Volcanoes in Iceland erupt at intervals of approximately 50-80 years,” explains Thorvolder Thordarson, an expert on Icelandic volcanoes at the UK’s University of Edinburgh. “And the increase in seismic activity over the past ten years indicates that we have most likely entered an active phase of eruptions "That's why it was so unusually quiet in the second half of the 20th century." In short, volcanologists predict new trials for Europe that will last 60 years or more, with a peak between 2030 and 2040.

The information obtained by brave researchers is also indicated in the Guinness Book of Records. For example, the highest active volcanoes are located in South America on the territory of Ecuador - these are Cotopaxi and Sangay, respectively 5896 meters and 5410 meters above sea level. The highest extinct volcano is Ojos del Salado in the Andean Cordillera on the border of Argentina and Chile, which rose 6880 meters above sea level.

Agafonova Alena, Terekhovich Anna

Report to the city conference "Profession Geographer"

Completed by 9a grade students

Presentation attached

Goal of the work: Get to know and study the profession of volcanologist, its features and specifics.

Tasks:

1. Study, collect and systematize material on the topic

2. Prepare a presentation of the profession.

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AOU school No. 6 of Dolgoprudny

ABSTRACT

“Profession volcanologist”

Completed by: Agafonova Alena,
Terekhovich Anna, 9a grade

Head: Isakova E.V.

Dolgoprudny 2012

About the head

Introduction

Goal of the work: Get to know and study the profession of volcanologist, its features and specifics.

Tasks:

1. Study, collect and systematize material on the topic.

2. Prepare a presentation of the profession.

Volcanologists study volcanoes. The first scientific observations of a volcanic eruption were made by the Romans Pliny the Elder and his nephew Pliny the Younger on August 24, 79. On the day of the catastrophic eruption of Vesuvius, Pliny the Elder - the head of the Roman fleet and scientist, author of 37 books of “Natural History” - tried to take out the inhabitants of the villas on ships from coast of the Gulf of Naples. Ash and pumice stones were already falling thickly on the coast. After landing, Pliny the Elder died, suffocating in a cloud of volcanic gases. Pliny the Younger later accurately described the eruption in two of his letters. In his honor, such eruptions, in which a powerful stream of volcanic gases, ash, pumice, slag and bombs hit a height of 10 km or more, are called Plinian.

The first volcanological observatory appeared on Mount Vesuvius in 1841 (Italy). At the beginning of the 20th century, volcanological observatories were created in the USA, Japan, Indonesia and other countries. Networks of volcanological observatories quickly merged into national volcanological services.

The development of domestic volcanology is associated with the development of the eastern outskirts of Russia. We remember and honor the famous explorer of Kamchatka S.P. Krasheninnikov, who described in 1755 “the fire-breathing mountains of Kamchatka and the dangers arising from them.”

The tasks of volcanology, as is known, include the study of volcanic and magmatic activity on Earth and other planets.

In Russia, in 1935, a volcanological station was opened in the village. Klyuchi, which in 1943 was transformed into the Laboratory of Volcanology of the USSR Academy of Sciences in Moscow, and in 1962 turned into the Institute of Volcanology of the Siberian Branch of the USSR Academy of Sciences in Petropavlovsk-Kamchatsky. Now it is the Institute of Volcanology and Seismology, Far Eastern Branch of the Russian Academy of Sciences in Petropavlovsk-Kamchatsky.

The institute has a special ship “Vulcanologist” at its disposal.

The vessel is designed to study underwater volcanism, to study the mineral resources of the ocean floor and its geological structure.

Externally, the ship looks quite unusual: a closed forecastle, an elongated superstructure, a significant camber of the hull towards the bow with a bow inclined forward, sides sloping towards the keel. The vessel's displacement is 1120 tons, crew - 40 people. On board it is equipped with geological, hydroacoustic, gas-hydrochemical, geophysical and noise direction-finding laboratories, and a computer center.

Volcanoes are often explored from an airplane. When studying the restless Italian volcano Etna, unmanned mini-planes of the CAM type, shaped like “flying saucers,” were used to take gas samples.

Who are volcanologists?

Volcanologists are a special caste of geologists; these people, as a rule, are true fans of their work. They are ready to climb into the very mouth of the fiery mountain, study its poisonous fumes and ashes, take samples of lava. Studying volcanoes is quite difficult, they are sometimes monitored around the clock. Volcanologists also study extinct and destroyed ancient volcanoes, since this knowledge is very important for geology , as they help to piece together a picture of eruptions of past years and even predict future cataclysms. Volcanologists also participate in the development of various methods of using heat and steam from hot springs for agricultural needs, which is of great practical importance. During an eruption, they monitor the direction of the ash, report the direction of the ash to the weather service and air traffic controllers. Studying active volcanoes involves great risk. After all, you have to work surrounded by hot lava, suffocating gases and hot dust, every second exposed to the danger of a volcanic explosion. To partially reduce the danger, volcanologists use special protective equipment. They wear heat-insulating clothing and shoes, which are covered with a layer of aluminum or other metal that reflects heat. They wear special protective helmets on their heads. To protect against gases, gas masks and gas masks are used. The volcanic heat burns your hands, the acid from the volcanic rocks corrodes your clothes.

Almost all books on volcanology describe the famous “drift” of two volcanologists, V.P. Popkova and I.Z. Ivanov, who were on a lava flow flowing from the Klyuchevskaya Sopka volcano. These scientists floated on the lava crust for more than two kilometers, moving with the lava flow, constantly taking temperature measurements and taking gas samples. Initially they wanted to walk along the "bank of lava flow 2", but the terrain did not allow this. That's why they dared to do such an experiment. “While working, we laid asbestos sheets under our feet, and yet we often had to stand like storks on one leg,” wrote V.F. Popkov, one of the participants in this dangerous experiment, in his report.

Professionally important qualities of people in this profession are: physical endurance, spatial imagination, observation, attention, logical thinking, emotional-volitional stability, good hearing.

Must know:

Geological knowledge about rocks, magmas and endogenous processes that arose under conditions of high temperatures and a wide range of pressures, as well as the processes of their formation and transformation.

The first female volcanologist

August 9, 1936 is a significant date in Russian volcanology. On this day, a woman climbed the smoking peak of the largest active volcano in Eurasia - Klyuchevsky - for the first time in the world, it was volcanologist Sofya Ivanovna Naboko. A detachment of three people managed to climb to the northwestern edge of the crater. Unique samples of fumarole gases, samples of lava, sublimates were selected, measurements of fumarole temperature and atmospheric pressure were carried out. We measured the height of the volcano using an aneroid - 4860 m. The air temperature was minus 14 degrees Celsius. The planned work program was completed. There was every reason to rejoice. But on the way back, a tragedy almost happened: topographer A.I. Dyakonov, in euphoria from conquering the volcano, began to sing, wave his arms, could not resist on the icy slope, fell, rolled and fell into a deep crack. It’s good that he caught the walls of the crack with a tripod tied to his backpack and hung, otherwise he would have broken. He couldn't get out on his own. It was impossible to even move, because... there was a danger of the toe breaking. Sofya Ivanovna recalled that when she and A. A. Menyailov carefully crawled to the crack, they heard faint cries for help from below. It was necessary to go down to the victim, tie him to a rope and pull him up. But there was little strength. In addition, Sofya Ivanovna was in the third month of pregnancy (by the way, this child himself would later become the famous volcanologist Igor Aleksandrovich Menyailov). A. A. Menyailov had to go down the rope, which was belayed by S. I. Naboko. Imagine the state of a young woman left alone above a crack on a steep slope of a volcano! All night, with incredible difficulties, two courageous men saved their comrade and warmed him up. Fortunately, everything ended well. The detachment returned to the camp at the base of the volcano in full force and with all the selected samples. Who knows how that ascent could have ended if such a selfless and brave woman had not been part of the squad. After all, an active volcano is a force of nature. Especially such a giant as Klyuchevskoy. Many climbers - both amateurs and experienced climbers - suffered on this volcano. Sofya Ivanovna, by her own admission, withstood this peculiar baptism by a volcano with honor and passed the test of loyalty to her chosen profession.

Where and how to become a volcanologist?

Volcanology is one of the rarest specialties. Becoming a volcanologist in Russia is not easy, since there is not a single educational institution that trains specialists in this field. At Moscow University, volcanological topics are covered in the Department of Petrology of the Faculty of Geology, in the Department of Geomorphology and Paleogeography of the Faculty of Geography, and in the Department of Mechanics of the Faculty of Mechanics and Mathematics. Schoolchildren can begin to acquire the knowledge necessary for volcanologists at the Geological School of Moscow State University (http://geoschool.web.ru), which offers free classes twice a week, and in the open lecture hall of the Geological Faculty of Moscow State University, which began operating in October 2011.

Conclusion

What attracts people to the unusual profession of volcanologist?

In earlier times, volcanologists were usually naturalists fascinated by the grandiose views of violent volcanic eruptions. But the days of descriptive volcanology are long gone. Modern science is increasingly armed with measure and number. Receives information from many sources, from people of various professions: physicists, chemists. mathematicians, geologists, mathematicians and others. It is this versatility, inherent in volcanology as a natural science, that prompts many scientists to devote their activities to the study of volcanoes and choose this profession.

Literature

K.G. Stafeev. Life of a volcano. M.: Education, 1998.

E.G. Malkhasyan., K.N. Rudich. The changing face of the Earth. M.: Nedra, 2003.

Introduction
I would like to present to your attention a work on the topic “Volcanoes”. I chose this topic because I once read Jules Verne's book Journey to the Center of the Earth. I realized that this is a very interesting and unusual natural phenomenon. And I wanted to learn as much as possible about volcanoes.

The relevance of research determined by the need to forecast and assess the danger of volcanic eruptions.

Object of study: volcanoes

Item: volcano model

Purpose of the study: simulate a working volcano model at home

Tasks:
- study additional literature and select interesting information about what a volcano is;
- find out how a volcano works;
- find out what volcanoes are;
- create a working model of a volcano at home;
- to conduct an experiment

Hypothesis: Is it possible to create a working model of a volcano at home?

Research methods: study and analysis of popular science literature

Volcanoes
The word "volcano" comes from the name of the ancient Roman god of fire, Vulcan. The science that studies volcanoes is volcanology.
Volcanoes are geological formations on the surface of the Earth's crust or the crust of another planet, where magma (a mass of molten rock located underground at very great depths) comes to the surface, forming lava, volcanic gases, rocks (volcanic bombs) and pyroclastic flow (a mixture of high-temperature volcanic gases, ash and rocks). The flow speed sometimes reaches 700 km/h, and the gas temperature is 100 - 800 o C.
Volcanoes can be active or dormant. An active volcano often erupts lava, ash and dust. When a volcano does not erupt for many years, it is called dormant. However, dormant volcanoes can begin to erupt even after a long period of inactivity. When eruptions finally stop, such a volcano is called extinct. Some volcanoes are distinguished by violent and colorful eruptions: fiery lava and hot clouds of gases are thrown high into the air. From other volcanoes, lava flows slowly and slowly, like boiling syrup and hot tar.

The structure of the volcano.
A crater is a depression in the form of a bowl or funnel formed on the top or slope of a volcano as a result of its active activity. The diameter of the crater can be from tens of meters to several kilometers, the depth - from tens to several hundred meters.
A vent is a channel through which lava moves.
Magma is a viscous liquid consisting of a mixture of various molten minerals and some mineral crystals that forms in the depths of the Earth. It resembles melting snow or frozen slush with ice crystals. Magma also contains water and dissolved gases.
Lava is magma poured onto the surface. Temperature 750 - 1250 oC.
Current speed is 300-500 meters per hour.
Depending on its chemical composition, lava can be liquid or thick and viscous. When magma rises through the earth's crust and comes to the surface, it is called an eruption.
Classification of volcanoes by shape
There are different forms of volcanoes, some of them are much more dangerous than others
Shield volcanoes (Fig. 1) are formed as a result of repeated emissions of liquid lava. This shape is characteristic of volcanoes that erupt low-viscosity basaltic lava: it flows from both the central crater and the slopes of the volcano. Lava spreads evenly over many kilometers. Like, for example, on the Mauna Loa volcano in the Hawaiian Islands, where it flows directly into the ocean.
Cinder cones (Fig. 2) eject from their vents only such loose substances as stones and ash: the largest fragments accumulate in layers around the crater. Because of this, the volcano becomes higher with each eruption. Light particles fly away over a longer distance, which makes the slopes gentle.
Stratovolcanoes, (Fig. 3) or “layered volcanoes,” periodically erupt lava and pyroclastic matter - a mixture of hot gas, ash and hot stones. Therefore, deposits on their cone alternate. On the slopes of stratovolcanoes, ribbed corridors of solidified lava are formed, which serve as support for the volcano.
Dome (Fig. 4) volcanoes form when granitic, viscous magma rises above the rim of the volcano's crater and only a small amount seeps out, flowing down the slopes. Magma clogs the volcano's crater, like a cork, which the gases accumulated under the dome literally knock out of the crater. Volcanoes-calderas. (Fig. 5) they explode so violently that they destroy themselves. Their eruptions are accompanied by very strong pyroclastic explosions. These volcanoes killed the largest number of people, and the consequences of their explosions made the surrounding areas deserted.

Eruption process.
Our planet Earth resembles an egg: on top there is a thin hard shell - the earth's crust, underneath there is a viscous layer of hot mantle, and in the center there is a solid core. The earth's crust is called the lithosphere, which is translated from Greek as “stone shell.” The thickness of the lithosphere is on average about 1% of the radius of the globe. On land it is 70-80 kilometers, but in the depths of the oceans it can be only 20 kilometers. The temperature of the mantle is thousands of degrees. Closer to the core, the temperature of the mantle is higher, closer to the crust - lower. Due to the temperature difference, the mantle substance is mixed: hot masses rise upward, and cold masses descend (just like boiling water in a pan or kettle, but this only happens thousands of times slower). The mantle, although heated to enormous temperatures, is due to the colossal pressure in the center of the Earth not liquid, but viscous, like very thick tar. The lithosphere seems to float in a viscous mantle, submerging slightly into it under the weight of its weight.
Reaching the base of the lithosphere, the cooling mass of the mantle moves horizontally for some time along the solid rock “shell”, but then, having cooled, it descends again towards the center of the Earth. While the mantle moves along the lithosphere, pieces of the earth's crust (lithospheric plates) inevitably move along with it, while individual parts of the stone mosaic collide and creep onto each other.
The part of the plate that was below (on which another plate crawled) gradually sinks into the mantle and begins to melt. This is how magma is formed - a thick mass of molten rocks with gases and water vapor. Magma is lighter than the surrounding rocks, so it slowly rises to the surface and accumulates in so-called magma chambers. They are most often located along the plate collision line.
The behavior of hot magma in a magma chamber really resembles yeast dough: the magma increases in volume, occupies all available space and rises from the depths of the Earth along cracks, trying to break free. Just as dough lifts the lid of a pan and flows over the edge, so magma breaks through the earth's crust in the weakest places and breaks out to the surface. This is a volcanic eruption.
A volcanic eruption occurs due to the degassing of magma, that is, the release of gases from it. Everyone knows the degassing process: if you carefully open a bottle of a carbonated drink (lemonade, Coca-Cola, kvass or champagne), a pop is heard, and smoke appears from the bottle, and sometimes foam - this is gas coming out of the drink (that is, it is degassing) .
Products of volcanic eruptions. An eruption is caused by magma breaking through the earth's crust. Most eruptions occur when a volcanic conduit or volcanic crater is blocked. Due to the magma coming from below, the pressure increases. When the plug blocking the channel breaks and the pressure is released, the gas in the magma bubbles boils, like a fizzy drink.
This is what causes a volcano to explode. When a volcano erupts, it scatters not only liquid lava, but also large chunks of solidified lava - called bombs - that crash to the ground up to two miles from the crater. Ash and volcanic gases form columnar volcanic clouds, sometimes rising to great heights.
The main products of an eruption are lava, ash, and other substances that come to the surface of the earth after the activity of the volcano. Volcanoes can emit significant amounts of toxic gases. Volcanic gases released by volcanoes rise into the atmosphere, but some of them can return to the surface of the earth in the form of acid rain. Quite serious consequences of acid rain for the body and health can be observed with manganese poisoning, which can also be found in rainwater in huge quantities.
Where are volcanoes common?
The Pacific coast of Central America is one of the most active areas of volcanic activity in the world. And in fact, more than two-thirds of the active volcanoes are located in this place, as well as many that ceased their activity relatively recently.
The reason is this: in these places the earth's crust is very weak compared to other areas of the globe. Where there is a weak section of the earth's crust, a volcano appears.
Main areas of volcanic activity (Fig. 5.)

Simulation of an active volcano model at home
DIY volcano model
But I can’t wait to touch everything with my own hands and see everything in reality - these splashes of fire, sparkling creeping lava, escaping clouds of smoke and splashes of a fountain of stones. This fiery spectacle will help us make a DIY Vulcan kit. Following strictly according to the instructions, using scissors, newsprint, adhesive paste, armed with the basics of geometry, we painstakingly make a model of our volcano step by step. The model is done, all that remains is to simulate a volcanic eruption
Conducting an experiment. Eruption.
After reading one of the articles on the Internet, I learned that you can simulate a volcanic eruption at home.
I needed the following materials for the experiment:
- baking soda (2 tablespoons)
- citric acid (70 m.l.)
- glass or iron jar (150 ml.)
- plasticine of different colors
- dishwashing liquid
Progress of the experiment:
1) Take the made model of the volcano
2) Pour 2 tbsp into the “crater”. soda
3) Pour 2 tbsp. dishwashing liquid
4) Pour in 50-70 ml of citric acid
5) Watching a “volcanic eruption”
Experiment:
-add more dishwashing liquid;
-add more vinegar;
-add small pieces of foam.
From the experiment we can draw the following conclusion. When baking soda and citric acid are combined, a chemical reaction occurs, releasing carbon dioxide, which bubbles, causing the mass to overflow over the edges of the “crater,” and the dishwashing detergent causes the “lava” to bubble more strongly. This chemical reaction has not only an external effect, but also a practical one: it is very popular in cooking. Housewives “quench” soda with vinegar and add it to the dough; the released carbon dioxide makes the dough fluffy, forming bubbles and air tracks in it.
So, in a playful way, I showed and explained the nature of the occurrence of volcanoes on Earth.

Conclusion
Having studied and analyzed popular scientific literature in detail, I learned a lot of new and interesting things about volcanoes. In fact, the volcano erupts because magma has accumulated in the volcanic chamber and, under the influence of the gas included in its composition, it rises to the top. In the crater of a volcano, the amount of gas becomes greater. The magma turns to lava, reaches the crater and erupts. Also that volcanoes are of great importance in nature. They carry with them both destructive and creative power. We can only observe and explain what is happening. Man cannot stop, change, or even prevent these formidable natural phenomena.
Using a chemical reaction, I showed and explained the nature of the formation of volcanoes on Earth. Thus, he satisfied his cognitive interest, and also interested his classmates in this experiment.

Municipal budgetary educational institution

Lyceum No. 4

Why do volcanoes erupt?

Research project

Krivosheev Timur Vladimirovich

3rd grade student

Supervisor:

Krivosheeva Natalya Evgenievna

primary school teacher

Dankov

2015

Table of contents

1.Introduction………………………………………………………………………………….……...2

Goals and objectives of the research work…………………………………….…2

2. Main part.

2.1 Questioning classmates…………………………………….….….. 3

2.2 Experience No. 1. Movement of magma from the bowels of the earth……………………………5

2.3. Experience No. 2.How does a volcano erupt?…………………..…6

2.4 Experience No. 3.Properties of volcanic stones ………...7

2.5 Consequences of volcanic eruptions…………………….8

3. Conclusions………………………………………………………………………………….…...… 8

4. Conclusion………………………………………………………………………………...8

5. Bibliography……………….…………………………...........9

The year before last, I heard on the news about a volcanic eruption in Russia. The Klyuchevskaya Sopka volcano began to erupt in Kamchatka. I was interested in how and why this volcano woke up. These questions helped me decide on the topic of my research work. I decided to find out why volcanoes erupt.

Goal of the work - summarize and classify information about volcanoes.Find out the reasons why volcanoes erupt.

Tasks:

Find out what a volcano is?

Study the structure of a volcano.

Find out what kinds of volcanoes there are?

Conduct an experiment and find out how and why a volcano erupts.

Find out what consequences volcanic eruptions have.

Create a working model of a volcano at home.

Learn experimentally about the properties of stones of volcanic origin.

Research methods:

Conversations with adults.

Questioning classmates.

Study and analysis of various sources of information.

Conducting experiments.

Observations.

Hypothesis:

volcanoes erupt because there is a lot of liquid magma under the earth's crust, and therefore it comes out.

Questioning classmates

I began my search for reasons explaining why volcanoes erupt by conducting a survey among my classmates.

To the question “Why do volcanoes erupt?” The guys gave the most votes to the answer “from an earthquake.” They also believe that the sun and geographic location have a special influence on volcanic eruptions.

What is a volcano

From the Internet I learned that the word “Vulcan” comes from the name of the island of Vulcano off the coast of Italy, where, according to legend, one of the forges of the ancient Roman god of fire Vulcan (Hephaestus) was located.

I read in the encyclopedia that a volcano is a geological formation that appears above channels and cracks in the earth's crust, through which lava, volcanic gases and stones erupt onto the earth's surface.

Types of volcanoes:

Active - These are volcanoes that erupt regularly.

Extinct - These are volcanoes whose activity has ceased and they no longer erupt.

Asleep - these are volcanoes that were considered extinct, but suddenly began to act.

A volcano consists of: MAGMA OR LAVA - molten rocks saturated with gases. VENT - a channel through which magma rises to the crater. Crater - a bowl-shaped depression at the top of a volcano.

To find out where magma comes from, I first studied the structure of our planet. I learned that the Earth resembles an egg: on top there is a thin hard shell - the earth's crust, underneath there is a viscous layer of hot mantle, and in the center there is a solid core.

Inside the Earth, due to temperature differences, there is a constant movement of the mantle. Pieces of the earth's crust (tectonic plates) also move along with it.When plates collide, one plate goes down and begins to melt - turns into magma. Magma rises to the surface and accumulates in magma chambers.

Experience No. 1. Movement of magma from the depths of the earth

I decided to experimentally see what happens to magma when tectonic plates collide. To do this, I conducted my first experiment, “Movement of magma from the bowels of the Earth.” To do this, I immersed solid chocolate bars, which replaced tectonic plates, in “magma” yoghurt. Using sticks, I began to move my “tectonic plates.” The “plates” began to collide with each other, some plates went under others, and at this point the “magma” was pushed to the surface of the “plates”.

Conclusion:

The experience helped to understand how, under the influence of the movement of tectonic plates, magma moves to the surface of the earth.

Magma rises to the surface and accumulates in magma chambers. There it is under pressure, just like carbonated drinks in a closed bottle.

The gases that make up the magma tend to go out and lift the magma along the crater of the volcano. These gases are flammable, so they ignite and explode in the crater of a volcano. Gases, ash, hot rocks and magma burst out through the crater of the volcano.

Experience No. 2. How does a volcano erupt?

My second experience helped me figure out why magma starts to erupt from a volcano. I made a cone out of paper and gave it the color of a volcano. Place a glass inside the cone. I filled the glass with “lava” – a mixture of baking soda, liquid soap and red paint. Filled a volcano with vinegar and caused an eruption.

Conclusion:

The gas formed when vinegar reacts with soda raises the “lava” upward and an “eruption” occurs.

Experience No. 3. Properties of volcanic stones

For a long time I was passionate about collecting the collection of stones “Minerals. Treasures of the Earth." From it I learned that stones of volcanic origin were formed as a result of volcanic eruptions and the cooling of volcanic magma. They are characterized by durability, high density and good hardness. But there is one stone that is formed when magma releases a lot of gases, it foams and cools. This is pumice.

This stone has a porous structure. The pores are filled with air. Therefore, pumice does not sink. I decided to test this experimentally. I took stones of volcanic origin from the collection: granite, obsidian, gneiss, galena, basalt, andesite and pumice. Immersed them in water. All the stones sank, but the pumice remained on the surface of the water.

Conclusion:

Pumice is a rock of volcanic origin that does not sink in water.

Consequences of volcanic eruptions

Volcanic eruptions have a strong negative impact, causing colossal destruction and death.

But these fire-breathing mountains also give people hot water, energy, various rocks, metals and even precious stones. Volcanic ash increases soil fertility, so volcanoes bring not only destruction, but also benefit.

conclusions

1. While working on this project, I plunged into the world of fascinating experiences, became acquainted with the structure of a volcano and the process of its eruption, and learned that volcanoes bring not only harm, but also benefit.

2. My hypothesis that a volcanic eruption occurs because there is too much magma was partially confirmed. As a result of my research and experiments, I concluded that a volcanic eruption occurs because magma is lifted to the surface of the Earth by the gases contained in it.

Conclusion

I found the answer to my question "Why do volcanoes erupt". I would like morestudy the giant volcanoes in more detail and find out whether it is possible to predict and eliminate the consequences of the eruptions of these giants.

I also want to present my work to my classmates and hope to get them interested in my research.

3. “Volcanoes” by Christina Godin, Children's Encyclopedia Machaon

4. Encyclopedia. “Minerals. Treasures of the earth."

5. Great Russian Encyclopedia / Ch. ed. Yu. S. Osipov. - M.: Scientific. publishing house "BRE", 2004.