. What will happen if global warming occurs? Eruption 1452 impact on climate

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According to the latest data, since 2015, due to global climate change, supervolcanoes began to suddenly wake up all over the planet. On our planet, both on land and under water, there are many supervolcanoes, the eruptions of which can lead to serious consequences.

A supervolcano is a bowl-shaped depression called a caldera, formed by the collapse of rock after a large-scale eruption of this volcano in the past. Unlike ordinary volcanoes, supervolcanoes do not erupt, but explode. And in terms of power, the eruption of a supervolcano exceeds ordinary volcanoes many thousands of times.

As a result of the action of supervolcanoes in the past, inevitable climatic changes occurred, because more than 1,000,000,000,000 volcanic matter fell into the surrounding space, which led to a change in the chemical composition in the atmosphere, and also prevented the penetration of sunlight. This has repeatedly caused global cooling and the extinction of animals and plants.

7 BIGGEST SUPERVOLCANOES ON EARTH

Today it is known about the 20 largest supervolcanoes, which are located in different parts of our planet.

The largest of them are:

Yellowstone Caldera, North America

Aira Caldera, Japan

Toba Caldera, Indonesia Sumatra

Long Valley Caldera, California, USA

Taupo Volcano, North Island, New Zealand

Caldera Valles, New Mexico, USA

Caldera Campi Flegrei, Italy

Starting from 2015, the activation of supervolcanoes began, which "slept" for several thousand, or even millions of years.

In addition, other volcanoes show signs of activity:

In December 2018, the Krakatau volcano erupted in ANAK-KRAKATAU, INDONESIA.

In March 2017, the SABANKAYA volcano, PERU exploded 36 times in a day.

Aeolian Islands, Italy.

In January 2019, the volcano MANAM, PAPUA NEW GUINEA erupted.

In March 2019, the Mexican volcano POPOCATEPETL erupted.

On July 3, 2019, there was a powerful eruption of the Stromboli volcano, located on the Italian island of the same name.

And these are far from all cases of volcanic eruptions that have occurred on the planet in just the last 8 months (December 2018 - July 2019). What is the reason for such high volcanic activity, and what awaits our planet in the near future?

EARTHQUAKES ARE THE TRIGGER FOR VOLCANO ERUPTIONS

Earthquakes and volcanic eruptions are interconnected. This can be seen if you pay attention to the maps of volcanic and seismic activity - as a rule, they almost completely coincide. Interestingly, both of them most often occur at the junction of tectonic plates. Earthquakes are, in fact, stress relief when one plate sinks under the second or their expansion occurs. Along all the boundaries of tectonic plates is magma, which, rising to the surface, forms volcanoes. The movements of magma within volcanoes can also cause earthquakes, as well as the movements of the slopes of volcanic rock and the plates located under them.

On March 11, 2011, a powerful earthquake of magnitude 9.0 occurred in Japan, which caused a tsunami. It was the most powerful earthquake in the history of observations, which was included in the ten largest natural disasters not only in the Japanese archipelago, but also in the world. According to experts, earthquakes of this level occur no more than once every 600 years. As a result of the earthquake, a severe accident occurred at the FUKUSHIMA-1 nuclear power plant.

In addition, the data recorded by the satellite after the event testified that the island of Honshu, or rather its eastern coast, has shifted 2.5 m to the east. At the same time, the Osika Peninsula, which is located in the northeast of Honshu, also moved 5.3 m to the southeast and sank 1.2 m.

In the scientific community, this phenomenon caused great concern, because the consequences of the changes: the flooded territory and displacements turned out to be much more than preliminary calculations. And this catastrophe showed how the modern scientific world is not prepared for such events. Moreover, this happened in Japan - one of the most highly developed and advanced countries in terms of technical development. But, at the same time, the earthquake showed that this is a common misfortune for all mankind, which can lead to serious consequences not only within one country, but throughout the world as a whole.

In fact, the Pacific lithospheric plate became more active in the subduction zones, and this became an indicator that a new phase of seismic activity is growing, which is associated with the acceleration of the movement of this plate. This happened as a result of large-scale changes in secular magnetic variations in the Japanese archipelago due to the displacement of geomagnetic poles located in Eastern Siberia and the Pacific Ocean. And first of all, this was influenced not by man-made, but by cosmic factors.

Scientists who analyzed the natural disaster that happened, found that before the earthquake, anomalies of the magnetic field appeared. At the same time, assumptions were put forward that the tectonic stress in the “unworked zones” would be at a critical level. And in 2015, a series of catastrophic earthquakes with a magnitude of over 8.0 was supposed to happen. This could lead to the most serious consequences, given that the country has a large number of nuclear power plants, as well as the Aira supervolcano.

AIRA SUPERVOLCAN

Since 2013, the scientific groups of the ALLATRA International Public Movement began to study volcanology, which was associated with the need to study neutrino emissions and the septon field, as well as the search for new forecasting methods. Observing the behavior of neutrinos that come from the depths, scientists have found that in the so-called "focal" zones of the planet there is increased neutrino radiation. And this indicates that the processes occurring in the bowels are beginning to acquire an irreversible character.

And most of all, scientists are alarmed by the fact that more than 7% of all volcanoes on our planet are concentrated here. And the greatest danger today is the Aira supervolcano, which, due to the activity of the volcanoes of this caldera and the danger of earthquakes in the Japanese archipelago, poses a very great danger.

The ALLATRA international group of scientists, which is engaged in a new area of climate engineering, also conducted research on the territory of the Japanese archipelago. Specialists recorded an atypical decrease in the radiation background, relative stability in the area, due to the activation of compensatory mechanisms that discharge the compression stress, due to redistribution to many small earthquakes. After all, the earthquake that occurred off the coast of Japan in 2011, according to all forecasts, could cause the eruption of the Aira supervolcano, but so far this has not happened ...

Naturally, this is only the first research in the field of volcanology and the behavior of the septon field and neutrinos. And this dynamically developing area of science allows us to study the mechanisms and associated risks that can generate such dangerous phenomena as volcanic eruptions. And most importantly, this will allow in the future to receive information about the danger of volcanic activity in any region remotely, safely and long before the upcoming event, as well as to use adaptive mechanisms to reduce or eliminate the consequences of volcanic activity.

The first encouraging results of this level were obtained from observation of the Aira caldera. Studies that have been conducted since 2013 suggest that adaptive mechanisms are able to block undesirable consequences that create conditions for a dangerous development of events.

Also, in the process of studying, the huge role of cosmic factors that influence the activation of changes within the planet was revealed, as evidenced by such phenomena as the tension of the septon field and neutrino radiation. The principle of operation of adaptive mechanisms is based on receiving feedback: when responding to an internal or external change, they stimulate an ezoosmic impulse, which creates conditions for active and adequate counteraction, equal in strength to activation at the ezoosmic level. And such stimulation occurs as long as the endogenous and exogenous forces are balanced, which provoke the occurrence of such phenomena as volcanic eruptions and earthquakes.

Adaptive mechanisms have the ability to maintain a relative level of security despite the constant variability and instability of the given environment.

But how long-term can this project be? And is this the only danger threatening humanity?

YELLOWSTONE

Yellowstone is one of the largest supervolcanoes. The width of the caldera reaches many kilometers, and the size of the caldera determines how devastating the consequences of a supervolcano eruption can be.

Today, Yellowstone is better known as a nature reserve located on the territory of 3 states - Wyoming, Idaho and Montana. Yellowstone (in the lane yellow stone), got its name because of the abundance of yellow rocky canyons in it. In the very center is one of the largest high-altitude lakes in North America, and it is located at an altitude of 2356 m.

The park contains 450 of the 970 geysers known to date. Also, the reserve attracts attention with very picturesque landscapes and rich flora and fauna. It has many waterfalls located near the Grand Canyon.

But Yellowstone is not only a beautiful nature reserve and great views. First of all, it is an active supervolcano, which is entering the active phase. The Yellowstone Caldera was formed more than 600 thousand years ago as a result of a large-scale volcanic eruption. At a depth of 8 km below the caldera is a huge magma chamber, and below is a magma reservoir, 4 times the volume of the chamber. The area of the Yellowstone volcano is about 4000 km2.

Starting from the 80s of the last century, scientists began to record tremors in the caldera, with a magnitude of up to 3.0 points. On March 16, 1992, a large earthquake occurred, with a magnitude of 4.1. Since 2013, the number of earthquakes has increased dramatically, while the hypocenter has become closer and closer to the earth's surface. In July-August 2018, the peak of earthquakes in Yellowstone occurred.

From 1985 to 2015, from 1.5 to 2 thousand earthquakes were recorded annually. In July 2017, 1171 earthquakes occurred here, in August - 1029, in February 2018 - 596. The hypocenter of all these earthquakes was at a record shallow depth - from 12 to 1.7 km. And this may indicate that magma is rising to the surface.

If the volcano comes into action, then up to 2.5 thousand m3 of volcanic matter can be erupted into the atmosphere and even the stratosphere. This will destroy all living things within a radius of thousands of kilometers.

Another sign that the supervolcano may wake up is that the activity of geysers has increased significantly in 2018. The appearance of geysers is associated with the processes occurring in magma and their activation may indicate an increase in volcanic activity. So, the highest geyser Steamboat over the past year erupted 33 (!) times, which was a record for the last 30 years. In addition, if earlier the duration of the geyser eruption was no more than 30 minutes, one of the latest eruptions lasted as much as 1.5 hours!

Also, data obtained by the Department of Water Resources indicates that the temperature of the rivers flowing near Yellowstone Park has risen by 10 degrees. And it happened in February, which is very alarming, because it cannot be called natural.

AIRA AND YELLOWSTONE - HOW ARE THEY RELATED?

During the observation of supervolcanoes, it was found that there is a close relationship between the processes that occur in the Aira caldera and the Yellowstone caldera, even though the Pacific plate lies between them.

Scientists have found that the processes that occur in the bowels of the planet are often interconnected and even interdependent. This is also evidenced by the fact that the septon field strength and neutrino radiation, despite the adaptive mechanisms activated in the area of the Airy supervolcano, remained at the same level.

This suggests that energy is accumulating in the bowels of the Earth, which can provoke a planetary catastrophe, and it will happen in the coming decades. But if two supervolcanoes - Yellowstone and Aira - come into action at the same time, this can completely destroy human civilization.

After the activation of the adaptive mechanisms, the seismic activity in the Aira caldera and the Yellowstone caldera were at the same level. Naturally, the influence of adaptive mechanisms, which were developed on the basis of PRIMORDIAL ALLATRA PHYSICS, and which reveal the secret of the deep sources of the Earth, is very important during the period of increasing global climate change.

With the development of PRIMORDIAL ALLATRA PHYSICS, it is quite possible to learn how to control natural processes today. Of course, adaptive mechanisms are a temporary measure. It will not be possible to avoid changes associated with the processes occurring in the hydrosphere, lithosphere, and atmosphere. Observing the atypical behavior of neutrinos, experts came to disappointing conclusions.

With a probability of 70% in the next 10 years, due to major eruptions, the Japanese archipelago can be destroyed. The probability that this will happen in the next 18 years is 99%!

But given the increase in climate change, increased volcanic activity and space factors, this can happen at any moment. This is especially alarming because millions of people live in this area. And today we need to unite and solve this problem in order to have time to save the lives of 127 million people by moving them to safe places of residence.

The branch of science concerned with the study of volcanic activity is quite young and still little studied. Its rapid development requires the involvement of a large number of specialists from various scientific fields. And first of all, these should be people who, absolutely disinterestedly, in their free time, could study volcanology, to save our planet, and not for the sake of earning money or obtaining higher scientific degrees and positions.

THE NORTH AMERICAN LITHOSPHERE PLATE IS NOT A COMPLETE

When studying a new direction in geoengineering, it was revealed that there is a specific discrepancy between the data that is provided to the public and what is actually happening. For example, a continental fault is forming in the North American lithospheric plate, which will actually divide the United States into two parts. And given that the tension along the fault line is growing every day, it is impossible to predict when this catastrophe will happen ...

On July 4, 2019, an earthquake with a magnitude of 6.4 occurred in Southern California, and a day later there was another earthquake with a magnitude of 7.1, which became the largest in the last 20 years. The California earthquake caused a series of 1.4 thousand tremors, which further alarmed seismologists, since the hypocenter of both earthquakes was located in the San Andreas Fault, where the North American plate collides with the Pacific. According to official information in the media, earthquakes occurred due to the fact that these two plates began to collide and rub against each other.

And despite the fact that small earthquakes constantly occur in California, on average about 3 times a day, not all of them are dangerous and even somewhat familiar to this region. However, there are those that pose a serious danger, so it must be remembered that an earthquake can occur here at any moment, which will cause great destruction. And every time, with an increase in small earthquakes, there is a possibility that a stronger and more destructive earthquake will occur. In any case, there are cases in history when strong earthquakes happened after shocks of small force.

The number of earthquakes in California previously reached about 400 per year, but on July 4, more than 100 earthquakes occurred in just one day, indicating an increase in the frequency of earthquakes in this region. And this is a sign of an impending powerful earthquake that can happen at any moment.

Over 10,000 earthquakes were recorded in the first week of July, Southern California is shaken by earthquakes virtually every minute, and most of them occur near the San Andreas Fault. Considering that the distance from the epicenter of earthquakes to the Yellowstone supervolcano is only a couple of hundred kilometers, this raises serious concerns about the beginning of an eruption. Although scientists currently deny this possibility, calling the California earthquakes aftershocks, nevertheless, the USGS does not deny the fact that this forecast may change if there is a stronger earthquake that will move the plates near Yellowstone.

THERE IS AN EXIT!

Recent developments in the field of climatology make it possible to accurately determine the “problem place”, which in the near future may cause irreversible consequences both for a particular region and for the entire planet as a whole due to global climate change.

The latest developments in the field of geoengineering open up great opportunities for climate monitoring and multivariate analysis of the further development of events related to climate change.

This makes it possible to find and launch compensatory natural mechanisms that are aimed at changing climatic conditions and preventing their consequences.

To date, active research is being carried out in this direction, which have a solid scientific basis and practical confirmation. And the initial stage of development of this direction is already yielding serious stable results.

But in order to start actively applying advanced developments, it is necessary now to start globally changing the values and priorities of the whole society as a whole, otherwise they will be usurped in the hands of the ruling elite for even greater enslavement of people.

Only by uniting on a spiritual and moral basis can we create a new format of society where humanity, kindness, mutual assistance and conscience will dominate in a person, despite nationality, religion, social status and other conditions artificially created to divide society.

WHAT CAN WE DO NOW?

On May 11, 2019, the international online conference “Society. Last Chance” in the form of a round table that brought together thousands of people from many countries of the world. People gathered in the conference halls to look into each other's eyes and discuss the important issues that have matured for each of us today.

And many people, regardless of races, nationalities, religions and social status, honestly and openly discussed how society can get out of the existing consumer system and unite in the context of a global spiritual and moral crisis.

The following topics were covered at the conference:

The consumer way of society as a dead end in the development of modern civilization;

Search for ways out of the crisis without harming countries, peoples and every person living on the planet;

Why in the 21st century, at the highest point of the civilized development of society, there are still such problems as wars, discrimination, violence?

Who distorts and hush up the realities of our time and why the media serve the interests of individuals;

Why is there no humanity in society, despite the large number of religions.

The speakers of the event proposed to unite all of humanity in a year and on May 9, 2020, to gather all people who care about the problems of society on the second Saturday of May. To gather the whole world for the international online conference “SOCIETY. LAST CHANCE 2020" #allatraunites, to decide together how to create a creative society, while we still have a chance to do it.

The cataclysms growing every day testify that modern civilization has practically no time left. If we do not unite today and do not take any steps to consolidate the world community, tomorrow may not come. Only the unification of all mankind on spiritual and moral foundations can be a chance to save our civilization from destruction.

Vestnik FEB RAS. 2007. No. 2

Y. D. MURAVIEV

Volcanic eruptions and climate

The impact of volcanic activity on climate has been studied for over 200 years. And only in the last quarter of a century, when methods of remote sensing of the atmosphere were introduced into scientific practice, as well as core drilling of polar glaciers was mastered, approaches to solving the problem were outlined. The review considers the results of work in this direction. It is shown that, despite the clear progress, many issues of the mutual influence of volcanism and climate remain unresolved, especially the subtle processes of transformation of volcanic aerosols during transport in the atmosphere.

Volcanic eruptions and climate. Y.D.MURAVYEV (Institute of Volcanology and Seismology, FEB RAS, Petropavlovsk-Kamchatsky).

The influence of volcanic activity on climatic changes has been already studied for more than 200 years. And only during the last quarter of the previous century, when methods of remote sounding of the atmosphere were introduced into research practice, as well as ice core drilling of polar glaciers was mastered, some approaches to its solution were found. This review considers the results of works in this area. It is shown, that, despite an obvious progress, many issues of volcano-climate interaction remain unsolved, and especially thin processes of transformation of volcanic aerosols when carried in the atmosphere.

It is difficult to find in the nature of our planet a more grandiose and dangerous phenomenon than modern volcanism. In addition to a direct threat to humans, volcanic activity can have a less obvious, but at the same time large-scale impact on the environment. The products of powerful volcanic eruptions, entering the stratosphere, remain in it for a year or more, changing the chemical composition of the air and affecting the radiation background of the Earth. Such eruptions have a great impact not only on the regions adjacent to them: they can also cause a global effect, lasting much longer than the event itself, if the atmosphere is saturated with a large amount of ash particles and volatile compounds.

Ash layers from major prehistoric eruptions represent chronological stratigraphic horizons for entire regions and can be used in models for reconstructing paleowind directions during eruptive activity. Layers of tephra (loose clastic material transported from the crater to the place of deposition by air) are the basis for the direct correlation of land and ocean ash, they are very effective in dating ice cores and other deposits in which these layers are present. Volcanic eruptions (due to their effect on the atmosphere) can explain some unique short-lived climate phenomena, which should also be considered in the context of expected global warming (as a natural mechanism that can change long-term climate trends for a period of several years or more).

Volcanism is a natural phenomenon on a planetary scale, but volcanoes on the earth's surface are unevenly distributed, so the role of eruptions of different volcanoes in the modulation of certain climatic fluctuations may differ.

MURAVYEV Yaroslav Dmitrievich - Candidate of Geographical Sciences (Institute of Volcanology and Seismology FEB RAS, Petropavlovsk-Kamchatsky).

Features of the distribution of volcanoes

Paradoxically, the exact number of active volcanoes on Earth is still unknown. This is due to the fact that the dormant periods of individual volcanoes, such as the Academy of Sciences (Karymsky volcanic center) in Kamchatka, can reach several millennia. In addition, a large number of volcanic structures exist at the bottom of the seas and oceans of the planet. According to various researchers, there are from 650 to 1200 active volcanoes on the globe, which are in varying degrees of activity or in a dormant state. Most are located close to the boundaries of the lithospheric plates, either along divergent (Iceland, African rift system, etc.) or convergent (eg, island arcs and continental volcanic arcs of the Pacific region) margins. The geographical location of such margins indicates that active volcanoes are unevenly distributed, with a predominant concentration in low latitudes (from 20 ° N to 10 ° S - these are the islands of the West Indies, Central America, northern South America, Eastern Africa), as well as in middle and high northern latitudes (30-70 ° N: Japan, Kamchatka, the Kuril and Aleutian Islands, Iceland)).

Any volcano can strongly influence the natural landscape surrounding it as a result of the outpouring of lava and pyroclastic flows, the descent of lahars, and tephra emissions. However, there are only three types of eruptions that can cause a significant global effect.

1. Vulcan-type eruptions in volcanic island arcs. Large eruptions of this type produce huge eruptive columns that bring pyroclastic particles and gases into the stratosphere, where they can move horizontally in any direction. Such volcanoes typically erupt andesitic and dacitic lavas, and may also eject large volumes of tephra. Historical and prehistoric examples include Tambora (1815), Krakatoa (1883), Agung (1963) in the West Indies; Katmai (1912), St. Helens (1480, 1980), Mazama (5000 BP) and Ice Peak (11250 BP) in North America; Bezymyanny (1956) (Fig. 1) and Shiveluch (1964) in Kamchatka, etc., where tephra spread in the form of plumes for thousands of kilometers in the direction of the winds.

Rice. 1. The culmination of the paroxysmal eruption of Volk. Nameless March 30, 1956 "directed explosion" type. The eruptive column reached 35 km in height! Photo by IV.Erov

2. Eruptions with the formation of calderas in continental "hot spots". Large caldera-forming eruptions, often associated with continental "hot spots" associated with the mantle, left traces of one kind or another in the geological record of the Quaternary period. For example, major events were the eruption of the Sia]e tephra in the Toledo caldera (1370 ka BP) and the eruption of the Tsankawi tephra in the Wells caldera about 1090 ka BP. (both originated in present-day New Mexico, USA) and Bishop's in the Lang Valley Caldera in California about 700,000 years ago. . Tephra layers formed as a result of eruptions are characterized by a subcontinental distribution, according to estimates, they covered an area of up to 2.76 million km2.

3. The largest fissure eruptions. Fissure eruptions are generally non-explosive, as they involve basaltic magmas, which have a relatively low viscosity. The result is extensive basaltic sheets similar to those found on the Deccan Plateau (India) and the Columbia Plateau (Northwest Pacific Coast of the United States of America), as well as in Iceland or Siberia. Such eruptions can release gigantic volumes of volatile substances into the atmosphere, changing the natural landscape.

Climatic effects of volcanic activity

Most noticeably, the climatic effects of eruptions affect changes in surface air temperature and the formation of meteoric precipitation, which most fully characterize climate-forming processes.

temperature effect. Volcanic ash thrown into the atmosphere during explosive eruptions reflects solar radiation, lowering the air temperature on the Earth's surface. While the stay of fine dust in the atmosphere from a Vulcan-type eruption is usually measured in weeks or months, volatiles such as GO2 can remain in the upper atmosphere for several years. Small particles of silicate dust and sulfur aerosol, concentrating in the stratosphere, increase the optical thickness of the aerosol layer, which leads to a decrease in temperature on the Earth's surface.

As a result of the eruptions of volcanoes Agung (Bali, 1963) and St. Helens (USA, 1980), the observed maximum decrease in the temperature of the Earth's surface in the Northern Hemisphere was less than 0.1°C. However, for larger eruptions, e.g. Tambora (Indonesia, 1815), a decrease in temperature by 0.5°C or more is quite possible (see table).

Influence of volcanic stratospheric aerosols on climate

Volcano Latitude Date Stratospheric aerosol, Mt Temperature decrease in the Northern Hemisphere, °C

explosive eruptions

Nameless 56o N 1956 0.2<0,05

St. Helens 46o N 1980 0.3<0,1

Agung 8o S 1963 10<0,05

El Chichon 17o N 1982 20<0,4

Krakatoa 6o S 1883 50 0.3

Tambora 8o S 1815 200 0.5

Toba 3o N 75,000 years ago 1000? Big?

Effusive fissure eruptions

Lucky 64o N 1783-1784 ~100? 1.0?

Rosa 47o N 4 million years ago 6000? big

Rice. Fig. 2. Time series of acidity for the Crete core from the ice of central Greenland, covering the period 533-1972. Identification of eruptions most likely corresponding to the largest acidity peaks based on historical sources

Explosive eruptions can affect the climate for at least several years, and some of them can cause much longer changes. From this point of view, the largest fissure eruptions can also have a significant effect, since as a result of these events a huge volume of volatile substances is released into the atmosphere for decades or more. Accordingly, some acidity peaks in Greenland glacial cores are comparable in time to fissure eruptions in Iceland (Fig. 2).

During the largest eruptions, similar to those observed on the volcano. Tambor, the amount of solar radiation passing through the stratosphere decreases by about a quarter (Fig. 3). Giant eruptions, such as the one that formed a layer of tephra (volk. Toba, Indonesia, about 75 thousand years ago), could reduce the penetration of sunlight to values that make up less than a hundredth of its norm, which prevents photosynthesis. This eruption is one of the largest in the Pleistocene, and the fine dust ejected into the stratosphere appears to have resulted in near-universal darkness over a wide area for weeks and months. Then, in about 9-14 days, about 1000 km3 of magma was erupted, and the distribution area of the ash layer exceeded at least 5106 km2.

Another reason for possible cooling is due to the screening effect of H2SO4 aerosols in the stratosphere. Following , we assume that in the modern era, as a result of volcanic and fumarole activity, approximately 14 million tons of sulfur enters the atmosphere annually, with its total natural emission of approximately 14^28 million tons. of its oxides in H2S04 (if this value is considered unchanged over the considered time interval), approaches the minimum estimate of the direct entry of aerosols in the form of sulfuric acid into the stratosphere due to the volcanic eruption. Toba. Most of the sulfur oxides immediately enter the ocean, forming sulfates, and a certain proportion of sulfur-containing gases is removed by dry absorption or washed out of the troposphere by precipitation. Therefore, it is obvious that the eruption of Volk. Toba led to a multiple increase in the number of long-lived aerosols in the stratosphere. Apparently, the effect of cooling manifested itself most clearly in low latitudes, especially in adjacent regions.

Dim>ad536_sun

Overcast day "^Tobi flow)

No photMyitthesis TobaV (high) >Roza

t-"ut) moonlight 4

Rice. 3. Estimates of the amount of solar radiation penetrating through the stratospheric aerosol and/or fine dust veil, depending on their mass. Dots indicate major historical and prehistoric eruptions

regions - India, Malaysia. The “acidic” trace of VLC also points to the global significance of this phenomenon. Toba, recorded at depths of 1033 and 1035 m in the core of wells 3C and 4C at Vostok station in Antarctica.

Evidence of volcanic climate modulation over decades has also been obtained from the study of tree rings and changes in the volume of mountain glaciers. The paper shows that frost periods in the western United States, established using tree-ring dendrochronology, are in close agreement with recorded eruptions and can probably be associated with a haze of volcanic aerosols in the stratosphere on the scales of one or two hemispheres. L. Scuderi noted that there is a close relationship between the different thickness of the rings at the upper boundary of the growth of forests that are sensitive to temperature changes, the acidity profiles of the Greenland ice and the advance of the mountain glaciers of the Sierra Nevada (California) . A sharp decrease in tree growth was observed during the year following the eruption (which resulted in the formation of an aerosol sheet), and a decrease in the growth of rings occurred within 13 years after the eruption.

The most promising sources of information about past volcanic aerosols are, however, ice core acidity and sulfate (acid) series, because they contain material evidence of atmospheric loading of chemical impurities. Since ice can be dated on the basis of its annual accumulation, it is possible to directly correlate acidity peaks in the upper layers of ice with historical eruptions of a known period. Using this approach, early acidity peaks of unknown origin are also associated with a certain age. Apparently, such powerful eruptions in the Holocene as unknown events that took place in 536-537 years. and around 50 BC, or Tambora in 1815, led to a clear decrease in solar radiation and cooling of the planet's surface for one to two years, which is confirmed by historical evidence. At the same time, the analysis of temperature data suggested that the warming in the Holocene in general and in the 1920s–1930s in particular was due to a decrease in volcanic activity.

It is known that one of the most effective methods for studying volcanic activity in the past is the study of acidity and aerosol inclusions in ice cores of polar glaciers. The ash layers in them are effectively used as temporary benchmarks when compared with the results of paleobotanical and geological studies. Comparison of the thickness of volcanic ashfalls at different latitudes contributes to the clarification of circulation processes in the past. Note that the screening role of aerosol in the stratosphere is much stronger in the hemisphere where the injection of volcanic particles into the stratosphere took place.

Considering the possible impact on the climate of eruptions, primarily low-latitude volcanoes, or summer eruptions in temperate or high latitudes, it is necessary to take into account the type of volcanic material. Otherwise, this may lead to a multiple overestimation of the thermal effect. Thus, during explosive eruptions with dacitic magma (for example, the St. Helens volcano), the specific contribution to the formation of H2SO4 aerosols was almost 6 times less than during the Krakatoa eruption, when about 10 km3 of andesitic magma was ejected and approximately 50 million tons of H2B04 aerosols. In terms of the effect of atmospheric pollution, this corresponds to an explosion of bombs with a total capacity of 500 Mt and, according to , should have significant consequences for the regional climate.

The eruption of Laki, apparently, to some extent caused a cooling at the end of the 18th century. in Iceland and Europe. Based on the acidity profiles of ice cores in Greenland, which reflect volcanic activity, it can be noted that volcanic activity in the Northern Hemisphere during the Little Ice Age correlates with general cooling.

The role of volcanic activity in the formation of precipitation. A common belief is that in the formation of atmospheric precipitation, the primary process under natural conditions at any temperature is the condensation of water vapor, and only then ice particles appear. Later it was shown that even with repeated saturation, ice crystals in perfectly clean moist air always arise due to the homogeneous appearance of droplets with subsequent freezing, and not directly from vapor.

It was experimentally determined that the rate of nucleation of ice crystals in supercooled water drops under homogeneous conditions is a function of the volume of the supercooled liquid, and the lower this volume is, the lower this volume is: drops with a diameter of several millimeters (rain) are cooled to a temperature of -34 + -35 ° C before freezing , and a few microns in diameter (cloudy) - up to -40оС. Usually, the temperature of formation of ice particles in atmospheric clouds is much higher, which is explained by the heterogeneity of the processes of condensation and crystal formation in the atmosphere due to the participation of aerosols.

During the formation of ice crystals and their accumulation, only a small part of aerosol particles serve as ice-forming nuclei, which often leads to supercooling of clouds to -20°C and below. Aerosol particles can initiate the formation of an ice phase both from supercooled liquid water by freezing droplets from the inside, and by sublimation. A study of sublimated snow crystals collected in the Northern Hemisphere showed that in about 95% of cases, one hard core was found in their central part (mainly 0.4-1 microns in size, consisting of clay particles). At the same time, clay particles and volcanic ash are most effective in the formation of ice crystals, while sea salts prevail in cloud drops. Such a difference may be important in explaining the higher rates of snow accumulation in the high latitudes of the Northern Hemisphere (compared to the Southern), as well as the greater efficiency of cyclonic transport of atmospheric moisture over Greenland than over Antarctica.

Since the most significant change in the amount of aerosols in the atmosphere is determined by volcanic activity, after an eruption and rapid washing out of tropospheric volcanic impurities, one can expect prolonged precipitation from the lower layers of the stratosphere with relatively low oxygen and deuterium isotope ratios and a low “primary” carbon content. If this assumption is correct, then some “cold” oscillations on the paleotemperature curve based on experimental studies of polar ice cores are understandable, which coincide in time with a decrease in the concentration of “atmospheric” CO2. This partly "explains" the cooling in the Early Dryas, which manifested itself most clearly in the North Atlantic basin approximately 11-10 thousand years ago. . The beginning of this cooling could have been initiated by a sharp increase in volcanic activity in the period of 14-10.5 thousand years ago, which was reflected in a multiple increase in the concentration of volcanogenic chlorine and sulfates in the ice cores of Greenland.

cooling (10.4 thousand years ago). In the Southern Hemisphere, as is known, the Early Dryas is not marked by a decrease in CO2 content in Antarctic ice cores and is weakly expressed in climatic curves, which is consistent with lower concentrations of volcanogenic aerosols than in Greenland. Based on the foregoing, it can be concluded that volcanic activity, in addition to direct impact on climate, manifests itself in imitation of an “additional” cooling due to increased snowfall.

Based on general information about the disproportionately higher (compared to Antarctica) content of aerosols as nuclei of condensation and crystallization of atmospheric moisture in Greenland, one can expect a correspondingly greater contribution of air components captured by precipitation (due to a general decrease in the level of crystallization) to the gas composition of glaciers. Higher volcanic activity in the Northern Hemisphere determines a greater impact on the isotopic composition of the ice sheet. This can manifest itself in a significant increase in the paleoisotopic signal here, for example, in the Early Dryas, compared with Antarctica. In the latter case, it is possible to simulate individual climatic events due to "volcanic" fluctuations in the isotopic composition.

Volcanic indices

Currently, a number of indices have been developed to assess the contribution of volcanism to climate change: the volcanic dust curtain index (DVI - Dust Volcanic Index), the volcanic explosive index (VEI - Volcanic Explosive Index), as well as MITCH, SATO and KHM, named after the names of the authors, who calculated them.

DVI. The first global generalization of the influence of volcanic eruptions on climatic consequences was made in the classic study by A. Lam and then revised (). A. Lam proposed an index specifically designed to analyze the influence of volcanoes on the weather, on a decrease or increase in atmospheric temperatures, and on large-scale wind circulation. A.Robok, using DVI to refine the calculations of the climatic characteristics of the Little Ice Age according to the energy balance model, showed that volcanic aerosols play a major role in producing cooling during this period of time.

The methods used to create the DVI are outlined by A. Lam. These included: historical data on eruptions, optical phenomena, radiation measurements (for the period after 1883), temperature parameters and calculations of the volume of erupted material. The DVI index is often criticized (for example, ), as it directly links climate anomalies to volcanic events, which leads to a simplified understanding of its use only in comparison with temperature changes. In fact, the DVI calculation is based solely on temperature information for several eruptions in the Northern Hemisphere between 1763-1882. and partially calculated on the basis of temperature data for some events of this period.

VEI. An attempt to quantify the relative magnitude of eruptions using VEI is based on scientific measurements and on subjective descriptions of individual eruptions. Despite the obvious value of these data, care must be taken in determining the frequency and intensity of volcanic events that occurred beyond the previous century, since many eruptions of the past remained unrecorded.

MITCH. This index was proposed by D.M. Mitchell, who also used A. Lam's data. This volcanic chronology covers 1850-1968, it is more detailed than DVI for the Northern Hemisphere, as the author included eruptions from DVI in the calculations<100, не использовавшиеся А.Лэмом при создании своего индекса. Был сделан вывод, что в стратосферный аэрозольный слой поступает около 1% материала от каждого извержения.

SATO index. Developed on the basis of volcanological information on the volume of emissions (from the report, from 1850 to 1882), measurements of optical attenuation (after 1882) and satellite data since 1979. The average indices of the optical depth of the atmosphere are calculated at a wavelength of 0.55 µm for each month separately for the Northern and Southern hemispheres.

Khmelevtsov index (KHM). Created from emissions calculations for known volcanic eruptions combined with 2D stratospheric transport and a radiation model. The series is represented by the average values of the monthly latitudinal distribution of the broadband apparent optical depth and other optical properties of the aerosol load of the stratosphere during 1850-1992.

Glacial chronology of volcanic eruptions

The main shortcomings of the chronologies of volcanic aerosol indices, in particular, information gaps about the period preceding the last one

two centuries, is largely intended to solve the glacial (glacial) index of volcanic activity developed in the last decade, based on the analysis of the acidity of glacial cores and the study of fluctuations in the productivity of mountain glaciers.

As a result of comparing acid profiles in the Greenland ice sheet, it was noted that the advance of mountain glaciers followed periods of time when the acidity of the ice became much higher than the background values. Conversely, the retreat of glaciers was noted during the favorable period of the Middle Ages (1090-1230), which coincides with the interval of low acidity in the glaciers of Greenland (Fig. 4). The close relationship between acid precipitation accumulation in Greenland and fluctuations in mountain glaciers over the past centuries indicates that decadal climate changes, recorded by the position of moraines on the earth's surface of mountain glaciers, are correlated with variations in the saturation of the stratosphere with volcanic aerosol.

Volcanic signal in glacial cores

An analysis of volcanic signals that have appeared simultaneously in cores from both polar regions of the planet over the past millennium is performed in . In it, the plot of the annual course of H + (ECM) was used as a nomogram of the total volcanic activity. Layers that show high levels of H+ concentration (above cut-off value 2a (3.3 mg eq/kg) from a mean value of 1.96 mg eq/kg),

Acidity of Ice Step

Greenland Shield Response Fluctuations of Alps Glaciers

0 12 3 4 "------ Advance

mg-eq. Retreat-----»

Rice. Fig. 4. The upper part of the Greenland ice acid profile (shaded area indicates values higher than the background) compared with the time series of five mountain glaciers (A - Argentiere, B - Brenva, G - Unter Grindelwald, M - Mer de Glace, R - Rhone) . Horizontal dotted lines indicate the onset of phenomena with an increase in acidity above background to levels of 2.4 µg-eq. H+/kg and above. Shaded areas to the right of the curve indicate a delay in the onset of glacial advance after the initial increase in acidity. The climax of the advance of glaciers is late after the increase in the peak of acidity by 1-2 decades

were determined as possible indicators of signs of volcanic activity in the ionic composition.

Of particular interest are approximately equal maximum values of the concentration level of nss SO42- (nss - sulfates of non-marine origin, or sulfate excess) in both hemispheres after the volcanic eruption. Krakatoa (6° S, 105° E), the maximum of eruptive activity of which was noted on August 26, 1883. Core analysis from the Crete borehole in central Greenland concluded that it took about a year for the signal from this eruption to reach the surface of Greenland, and about two years for the acidity to rise to a maximum at the point where the borehole was drilled.

Another example is the horizons of the maximum concentration of sulfate excess at bipolar points dated 1835 and 1832, which are 3-5 times higher than the background levels. Chemical signals in different cores, fixing the eruption of Tambor (8° S, 118° E), which occurred on April 5, 1815, as well as the signal of an unknown eruption around 1810, were noted earlier in the Crete core. The peak of the signal from the Tambora eruption in Greenland appeared a year after this event. High levels of nss SO42-concentration are also noted between accumulation layers, varying in different cores between 1450 and 1464. Most likely, all these signals represent the same event of 1459, identified in the most accurately dated core CR74; the observed differences are most likely due to the inaccuracy of the time scales at these depths, in particular for the SP78 core.

The 1259 layer is a volcanic event observed throughout the polar ice cores, and appears to be the largest eruptive event whose ejecta has been transported from a source around the world.

It should be noted that all the mentioned nss SO42- peaks in well CR74 were also found in the curve of ECM variations (electrical conductance values) in the core from Central Greenland (Greenland Ice-core Project - GRIP) with dates corresponding to the core of well CR74, with deviations ± 1 year. The results of the NBY89 core time scale analysis provide a continuous series of annual accumulation values for the last 1360 years (since 629). When using different time scales, the age of the bottom of the SP78 core with a depth of 111 m was determined from 980 ± 10 years; the bottom of the D3 18C core with a depth of 113 m - 1776 ± 1 year (208 annual layers from the surface of 1984); bottom of core CR74 -553 ± 3 years (1421st annual layer down from the surface of 1974).

The maximum peaks of H2SO4 found as a result of the study of ice cores from both hemispheres are present in samples taken from the horizons of 1259. Based on the results of chemical analysis of ice cores from Greenland and Antarctica, a bipolar stratigraphic chronology of the largest volcanic events over the past millennium was constructed. A key element of this chronology is the establishment of a near-realistic time scale for the NBY89 core (based on which large peaks of the volcanic index were traced for other Antarctic cores) and cross-dating of results from Antarctica and glacial cores from Greenland.

To assess the causes of climate change in the past over 2000 years, including the Medieval (Medieval warming) and the so-called Little Ice Age (LIA), reliable time series of atmospheric volcanic aerosol loading are needed. Outside of the last millennium, only two indices have been calculated based on various natural data and criteria. As a result, glacial cores remain the best sources of information on past volcanic aerosols (acidity and sulfate series), physical evidence of atmospheric loading.

The possibility of creating a new global volcanism index based on the use of ice core acidity and sulfate series was first shown for

period from 1850 to the present. By combining rows of 8 ice cores in the Northern Hemisphere and 5 in the Southern Hemisphere, an Ice Volcanic Index (IVI - Ice Volcanic Index) is proposed. These IVI chronologies are closely related to the 5 available volcanic indices for each hemisphere. Obviously, the results obtained from ice cores, compared with geological and biological information, in the future will allow to create more accurate and longer chronologies of volcanic activity.

Other characteristics that can add to the time scale of climate change are greenhouse gases, aerosols in the troposphere, variations in the solar constant, atmospheric-ocean interactions, and random, stochastic variations. Variability in the series of resulting peaks in Northern and Southern Hemisphere ice cores can be associated with both low levels of volcanism and other causes of sulfate emissions in the atmosphere, including the biological response to volcano-induced climatic changes.

In all series of IVI-chronologies, only 5 eruptions are visually visible: undated in 933 and 1259. (not listed in the VEI catalogue), the 1783 high latitude Laki eruption, the 1809 unknown eruption, and finally the 1815 Tambora (VEI = 7) eruption, which appears in both indices. The peak of the Laki eruption is present in the DVI series, but has a power of only VEI = 4, since it does not create a large spike on the graph. Baitou Volcano eruption in the Southern Hemisphere around 1010 with VEI = 7 does not show up in ice cores, nor do the 12 VEI = 6 eruptions that have visible peaks in the VEI catalog.

The reasons for the insufficient consistency of the results may be associated with large "noise" in the glacial series and the eccentricity of non-glacial indices. Due to less information about the eruptions, the lower part of the chronology is more distant from reality. However, the core record may be adequate for the Northern Hemisphere, at least during the modern period. As a test of its duration, we note that from 1210 to the present time there are 4 glacial cores taken in the Northern Hemisphere, three of which (A84, Crete and GISP2) cover the 20th century. Averaging these series from 1854 to the present and correlating this average (IVI*) with 5 other core indices showed that IVI* is closely related (at a 1% significance level) to the average from the core series, with MITCH, VEI, SATO and KHM, Northern Hemisphere (RF) glacial series, and with separate glacial chronologies from wells at Mt. Logan (Alaska) and 20D in Greenland.

The IVP chronology explains more than 60% of the variance in IVI for this time period, despite being compiled from GISP2, Crete and A84 cores only. Therefore, it, with the aerosol volcanic load of the atmosphere of the Northern Hemisphere, is almost as representative as the full IVI series.

In contrast, much less information has been collected for the Southern Hemisphere and is available for comparison with both ice cores and non-glacial indices. There are only two ice cores here, covering a chronology of about 1500 years - wells G15 and PSI. Obvious common peaks in the glacial records of the Southern Hemisphere are dated only to 1259 and a couple of eruptions in 1809 and 1815. These events had to be very strong and take place in the tropics in order to manifest themselves in this way at both poles of the planet. At the same time, in the glacial chronologies over the past 2000 years, there are a large number of events that are still not identified in the historical and geological records.

In conclusion, some problems related primarily to the interpretation of the results of the analysis of glacial cores should be noted.

Thus, volcanic eruptions covered by ice sheets can produce huge amounts of sulfate deposits, while not enriching the stratosphere and thus not having a massive effect.

Globally significant volcanic eruptions located at latitudes close to the sampled ice core (e.g. Katmai in 1912), through direct fallout of eruption products as a result of tropospheric transport and later deposition, may further complicate dating.

The relationship between aerosol loading of the atmosphere and the amount of sulfate deposited in snow is also not entirely clear. The mechanisms of exchange between the stratosphere and the troposphere, affecting the loading of the troposphere with sulfates, can be different for each volcanic eruption: due, firstly, to the synchronization of processes in each of the atmospheric layers, secondly, to the geographic confinement (longitude and latitude) of the stratospheric injection and and thirdly, natural synoptic variability. As noted, non-volcanic sources of sulfates also have their own variability, as a result of which the background and volcanic components can level or enhance each other.

There is a problem of interpretation and dating of ash and aerosol deposits, even for places near an active volcano, due to the different duration of the "life" of these particles in the atmosphere. Therefore, the ashes of the volcanoes closest to the drilling point are most clearly defined. For example, for Klyuchevskoy and Bezymyanny volcanoes in Kamchatka (Fig. 5).

Volcanoes affect the atmosphere, polluting it with solid and volatile products. Large eruptions can result in significant cooling (by 0.4-0.5°C) on the Earth's surface for a short period after the event, which can be felt in one of the hemispheres or around the world. Thus, eruptions are important for assessing future climate trends. However, due to the impossibility of making a long-term forecast and the lack of detailed records of past events (necessary to obtain reliable return intervals), an accurate calculation of the likely impact of future eruptions on warming and the greenhouse effect is doubtful. At best, it can be argued that if separate eruptions occur again, equal in magnitude to the Tambora eruption of 1815, then their result may be a suspension of the warming trend for several or more years. A large amount of additional research is needed around the world to create reliable and detailed records of past volcanic eruptions. In order to be useful, the chronology of past eruptions must be compiled with an error of no more than ± 10 years: only on the basis of data of such resolution is it possible to estimate them acceptable.

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Introduction

Volcanoes affect the natural environment and humanity in several ways. Firstly, the direct impact on the environment of erupting volcanic products (lavas, ash, etc.), secondly, the impact of gases and fine ash on the atmosphere and thus on the climate, thirdly, the impact of heat from volcanic products on ice and on snow, often covering the tops of volcanoes, which leads to catastrophic mudflows, floods, avalanches; fourthly, volcanic eruptions are usually accompanied by earthquakes, etc. But the effects of volcanic matter on the atmosphere are especially long-term and global, which is reflected in the change in the Earth's climate.

During catastrophic eruptions, emissions of volcanic dust and gases that sublimate particles of sulfur and other volatile components can reach the stratosphere and cause catastrophic climate changes. Thus, in the 17th century, after the catastrophic eruptions of the volcanoes Etna in Sicily and Hekla in Iceland, clouding of the stratosphere led to a sharp two-year cooling, massive crop failure and death of livestock, epidemics that swept all of Europe and caused a 30-50-th extinction of the European population. Such eruptions, often of an explosive style, are especially characteristic of island-arc volcanoes. In fact, with such eruptions, we have a natural model of "nuclear winter".

The emission of gases from passively degassing volcanoes as a whole can have a global impact on the composition of the atmosphere. Thus, Plinian and coignimbrite columns carried volcanic material into the troposphere with the formation of an aerosol cloud, polar haze, and disturbance of the state of the polar ozone layer.

Thus, the relevance of the topic is determined by the issue of Earth's climate change, which to a certain extent is facilitated by the activity of volcanoes active in the past and present.

The purpose of the study: to compare the characteristics of extinct and active volcanoes, to determine the degree of impact of volcanoes on the Earth's climate.

Object of study: volcanoes of the world.

Subject of study: the impact of volcanoes on climate change.

Research objectives:

· To reveal the essence of the concept of volcanoes;

· To study the general features of the climate;

· To consider areas of distribution of volcanoes;

· To study the peculiarities of the volcanoes of Kamchatka, the Kuriles and Iceland.

Hypothesis

Volcanoes are an indispensable part of the landscape of the earth's surface, forming not only the outer world of the mainland, the customs of the population, the inhabiting tribes, but also shaping and changing the climate of the Earth.

· Selection and generalization of information in the process of analyzing the literature on the selected topic;

· Classification of the main points of the study by the method of comparison and categorical - conceptual analysis of topics;

· Selection of visual - illustrative material;

· The study of reference, literary and local history literature, as well as materials from Internet sites;

collection, systematization and processing of the necessary facts and information;

selection and partial creation of illustrative material.

The scientific and practical significance of the work lies in the systematization and generalization of information about the impact of volcanic activity on climate change.

The work consists of an introduction, two chapters, a conclusion, a list of references, in the amount of 40 sources. The work presents 7 figures and 1 table.

1. Interaction of relief and climate

.1 Volcano - one of the elements of the Earth's surface

In the Tyrrhenian Sea in the group of Aeolian Islands there is a small island of Vulcano. Most of it is occupied by a mountain. Even in time immemorial, people saw how clouds of black smoke, fire sometimes escaped from its top, and red-hot stones were thrown to a great height. The ancient Romans considered this island the entrance to hell, as well as the possession of the god of fire and blacksmithing, Vulcan. By the name of this god, fire-breathing mountains later became known as volcanoes.

Volcanic eruption can last several days, sometimes months and even years. After a strong eruption, the volcano calms down again for several years and even decades.

Such volcanoes are called active.

There are volcanoes that erupted long ago. Some of them have retained the shape of a regular cone. There is no information about the activity of such volcanoes. They are called extinct, as, for example, in the Caucasus, Mount Elbrus, Kazbek, whose peaks are covered with sparkling, dazzling white glaciers. In ancient volcanic regions, there are heavily destroyed and eroded volcanoes. In our country, the remains of ancient volcanoes can be seen in the Crimea, Transbaikalia and other places. Volcanoes usually have the shape of a cone with slopes that are gentle at the bottom and steeper at the top.

If you climb to the top of an active volcano when it is calm, you can see a crater - a deep depression with steep walls, similar to a giant bowl. The bottom of the crater is covered with fragments of large and small stones, and jets of gas and steam rise from cracks in the bottom and walls. They calmly come out from under stones and from cracks or break out violently, with hissing and whistling. The crater is filled with suffocating gases: rising up, they form a cloud on the top of the volcano. For months and years, the volcano can quietly smoke until an eruption occurs.

Volcanologists have already developed methods that make it possible to predict the time of the onset of a volcanic eruption. This event is often preceded by earthquakes; an underground rumble is heard, the release of vapors and gases intensifies; their temperature rises; clouds thicken over the top of the volcano, and its slopes begin to "swell".

Then, under the pressure of gases escaping from the bowels of the Earth, the bottom of the crater explodes. Thick black clouds of gases and water vapor, mixed with ash, are thrown up thousands of meters, plunging the surroundings into darkness. With an explosion and a roar, pieces of red-hot stones fly from the crater, forming giant sheaves of sparks.

Rice. 1.1. - The eruption of Vesuvius near Naples in 1944. Explosions with great force threw thick clouds of gases and hot ash. Hot lava flows descended the slope, which destroyed several villages (V.I. Mikhailov)

Rice. 1.2. - Section of the volcano: 1 - magma chamber; 2 - lava flows; 3 - cone; 4 - crater; 5 - channel through which gases and magma rise to the crater; 6 - layers of lava flows, ash, lapilli and loose materials from earlier eruptions; 7 - remains of an old volcano crater

From black, thick clouds, ash falls on the ground, sometimes heavy rains fall, streams of mud form, which roll down the slopes and flood the surroundings. The flash of lightning continually cuts through the darkness. The volcano rumbles and trembles, molten fiery liquid lava rises along its mouth. It seethes, pours over the edge of the crater and rushes like a fiery stream along the slopes of the volcano, burning and destroying everything in its path.

During some volcanic eruptions, when the lava has a high viscosity, it does not pour out in a liquid stream, but piles up around the vent in the form of a volcanic dome. Often, during explosions or simply collapses, hot stone avalanches fall down the slopes along the edges of such a dome, which can cause great destruction at the foot of the volcano. During the eruption of some volcanoes, such hot avalanches erupt directly from the crater.

With weaker eruptions, only periodic explosions of gases occur in the crater of the volcano. In some cases, during explosions, pieces of hot, luminous lava are ejected, in others (at a lower temperature), already completely solidified lava is crushed, and large blocks of dark, non-luminous volcanic ash rise up.

Volcanic eruptions also occur at the bottom of the seas and oceans. Navigators find out about this when they suddenly see a column of steam above the water or “stone foam” floating on the surface - pumice. Sometimes ships come across unexpectedly appeared shoals formed by new volcanoes at the bottom of the sea.

Over time, these shoals are washed away by sea waves and disappear without a trace.

Some underwater volcanoes form cones that protrude above the surface of the water in the form of islands.

In ancient times, people did not know how to explain the causes of volcanic eruptions. This formidable phenomenon of nature plunged a person into horror. However, already the ancient Greeks and Romans, and later the Arabs, came to the conclusion that in the depths of the Earth there is a sea of underground fire. They believed that the disturbances of this sea cause volcanic eruptions on the earth's surface.

At the end of the last century, a special science, volcanology, separated from geology.

Now, near some active volcanoes, volcanological stations are being organized - observatories where volcanologists constantly monitor volcanoes. We have such volcanological stations in Kamchatka at the foot of the Klyuchevskoy volcano in the village of Klyuchi and on the slope of the Avacha volcano - not far from the city of Petropavlovsk-Kamchatsky. When any of the volcanoes begins to act, volcanologists immediately go to him and observe the eruption.

Volcanologists also explore extinct and destroyed ancient volcanoes. The accumulation of such observations and knowledge is very important for geology. Ancient destroyed volcanoes, active tens of millions of years ago and almost leveled with the Earth's surface, help scientists to recognize how the molten masses located in the bowels of the Earth penetrate into the solid earth's crust and what happens from their contact (contact) with rocks. Usually, at the points of contact, as a result of chemical processes, ores of minerals are formed - deposits of iron, copper, zinc and other metals.

Jets of steam and volcanic gases in the craters of volcanoes, which are called fumaroles, carry with them some substances in a dissolved state. Sulfur, ammonia, boric acid are deposited in the cracks of the crater and around it, around the fumaroles, which are used in industry.

Volcanic ash and lava contain many compounds of the element potassium and turn into fertile soil over time. They plant gardens or are engaged in field cultivation. Therefore, although it is not safe to live in the vicinity of volcanoes, villages or cities almost always grow there.

Why do volcanic eruptions occur and where does such a huge energy inside the globe come from?

The discovery of the phenomenon of radioactivity in some chemical elements, especially uranium and thorium, makes us think that heat accumulates inside the Earth from the decay of radioactive elements. The study of atomic energy further supports this view.

The accumulation of heat in the Earth at great depths inflames the substance of the Earth. The temperature rises so high that this substance should have melted, but under the pressure of the upper layers of the earth's crust, it is held in a solid state. In those places where the pressure of the upper layers weakens due to the movement of the earth's crust and the formation of cracks, the red-hot masses pass into a liquid state.

The mass of molten rock, saturated with gases, formed deep in the bowels of the earth, is called magma. Magma centers are located under the earth's crust, in the upper part of the mantle, at a depth of 50 to 100 km. Under the strong pressure of the released gases, magma, melting the surrounding rocks, makes its way and forms the vent, or channel, of the volcano. The liberated gases, by explosions, clear the way along the vent, break up solid rocks and throw their pieces to a great height. This phenomenon always precedes the outpouring of lava.

Just as the gas dissolved in a fizzy drink tends to escape when the bottle is opened, forming foam, so in the crater of a volcano, foaming magma is rapidly ejected by the gases released from it.

Having lost a significant amount of gas, magma pours out of the crater and already like lava flows along the slopes of the volcano.

If the magma in the earth's crust does not find an outlet to the surface, then it solidifies in the form of veins in the cracks in the earth's crust.

Sometimes magma penetrates along a crack, raises a layer of earth like a dome and solidifies in a shape similar to a loaf of bread.

Lava is different in composition and depending on this it can be liquid or thick and viscous. If the lava is liquid, then it spreads relatively quickly, forming lavafalls on its way. Gases, escaping from the crater, throw out red-hot fountains of lava, the splashes of which solidify into stone drops - lava tears. Thick lava flows slowly, breaks into blocks piled on top of each other, and the gases coming out of it tear off pieces of viscous lava from the blocks, throwing them high. If the clots of such lava rotate during takeoff, then they take on a spindle-shaped or spherical shape.

Rice. 1.3. - Earthquake-prone areas and major volcanoes.

.2 Climate - the main zonal component of the graphical shell

volcano climate zonal graphic

Climate, long-term weather patterns in the area. The weather at any given time is characterized by certain combinations of temperature, humidity, wind direction and speed. In some types of climate, the weather changes significantly every day or seasonally, in others it remains the same. Climate descriptions are based on statistical analysis of average and extreme meteorological characteristics. As a factor in the natural environment, climate influences the geographic distribution of vegetation, soils and water resources and, consequently, land use and the economy. Climate also has an impact on living conditions and human health.

Climatology is the science of climate that studies the causes of the formation of different types of climate, their geographical location and the relationship between climate and other natural phenomena. Climatology is closely related to meteorology - a branch of physics that studies the short-term states of the atmosphere, i.e. weather.

climate-forming factors

The climate is formed under the influence of several factors that provide the atmosphere with heat and moisture and determine the dynamics of air currents. The main climate-forming factors are the position of the Earth relative to the Sun, the distribution of land and sea, the general circulation of the atmosphere, sea currents, and the topography of the earth's surface.

The position of the earth. When the Earth revolves around the Sun, the angle between the polar axis and the perpendicular to the plane of the orbit remains constant and amounts to 23 ° 30 ". This movement explains the change in the angle of incidence of the sun's rays on the earth's surface at noon at a certain latitude during the year. The greater the angle of incidence of the sun's rays on The Earth in a given place, the more efficiently the Sun heats the surface. Only between the Northern and Southern tropics (from 23 ° 30 "N to 23 ° 30" S), the sun's rays at certain times of the year fall vertically on the Earth, and here The sun always rises high above the horizon at noon.Therefore, the tropics are usually warm at any time of the year.At higher latitudes, where the sun is lower above the horizon, there is less warming of the earth's surface.There are significant seasonal temperature changes (which does not happen in the tropics), and in winter, the angle of incidence of the sun's rays is relatively small and the days are much shorter.At the equator, day and night are always of equal duration, while on the floor Usakh day lasts the entire summer half of the year, and in winter the Sun never rises above the horizon. The length of the polar day only partly compensates for the low position of the Sun above the horizon, and as a result, the summer here is cool. In dark winters, the polar regions quickly lose heat and become very cold.

Distribution of land and sea. Water heats up and cools down more slowly than land. Therefore, the air temperature over the oceans has less daily and seasonal changes than over the continents. In coastal areas, where winds blow from the sea, summers are generally cooler and winters warmer than in the interior of the continents at the same latitude. The climate of such windward coasts is called maritime. The interior regions of the continents in temperate latitudes are characterized by significant differences in summer and winter temperatures. In such cases, one speaks of a continental climate.

Water areas are the main source of atmospheric moisture. When winds blow from warm oceans to land, there is a lot of precipitation. Windward coasts tend to have higher relative humidity and cloudiness and more foggy days than inland regions.

Atmospheric circulation. The nature of the baric field and the rotation of the Earth determine the general circulation of the atmosphere, due to which heat and moisture are constantly redistributed over the earth's surface. Winds blow from areas of high pressure to areas of low pressure. High pressure is usually associated with cold, dense air, while low pressure is associated with warm, less dense air. The rotation of the Earth causes air currents to deviate to the right in the Northern Hemisphere and to the left in the Southern Hemisphere. This deviation is called the Coriolis effect.

In both the Northern and Southern Hemispheres, there are three main wind zones in the surface layers of the atmosphere. In the intratropical convergence zone near the equator, the northeast trade wind converges with the southeast. Trade winds originate in subtropical areas of high pressure, most developed over the oceans. Air currents, moving towards the poles and deviating under the influence of the Coriolis force, form the predominant western transport. In the region of polar fronts of temperate latitudes, western transport meets cold air of high latitudes, forming a zone of baric systems with low pressure in the center (cyclones) moving from west to east. Although the air currents in the polar regions are not so pronounced, polar eastward transport is sometimes distinguished. These winds blow mainly from the northeast in the Northern Hemisphere and from the southeast in the Southern Hemisphere. Masses of cold air often penetrate temperate latitudes.

Winds in the areas of convergence of air currents form ascending air currents, which cool with height. Cloud formation is possible, often accompanied by precipitation. Therefore, in the intratropical convergence zone and frontal zones in the belt of predominant western transport, a lot of precipitation falls.

Winds blowing in higher layers of the atmosphere close the circulation system in both hemispheres. Air rising up in convergence zones rushes into areas of high pressure and sinks there. At the same time, with increasing pressure, it heats up, which leads to the formation of a dry climate, especially on land. Such downward air currents determine the climate of the Sahara, located in the subtropical high pressure belt in North Africa.

Seasonal changes in heating and cooling cause seasonal movements of the main baric formations and wind systems. Wind zones in summer shift towards the poles, which leads to changes in weather conditions at a given latitude. Thus, the African savannahs, covered with grassy vegetation with sparsely growing trees, are characterized by rainy summers (due to the influence of the intratropical convergence zone) and dry winters, when a high pressure area with descending air currents shifts to this territory.

Seasonal changes in the general circulation of the atmosphere are also affected by the distribution of land and sea. In summer, when the Asian continent warms up and a lower pressure area is established above it than over the surrounding oceans, the coastal southern and southeastern regions are affected by moist air currents directed from the sea to land and bringing heavy rains. In winter, air flows from the cold surface of the mainland to the oceans, and much less rain falls. Such winds, which change direction with the seasons, are called monsoons.

Ocean currents are formed under the influence of surface winds and differences in water density due to changes in its salinity and temperature. The direction of the currents is influenced by the Coriolis force, the shape of the sea basins and the outlines of the coasts. In general, the circulation of ocean currents is similar to the distribution of air currents over the oceans and occurs clockwise in the Northern Hemisphere and counterclockwise in the Southern Hemisphere.

Crossing the warm currents heading towards the poles, the air becomes warmer and more humid and has a corresponding effect on the climate. Ocean currents heading towards the equator carry cool waters. Passing along the western outskirts of the continents, they lower the temperature and moisture content of the air, and, accordingly, the climate under their influence becomes cooler and drier. Due to the condensation of moisture near the cold surface of the sea, fog often occurs in such areas.

The relief of the earth's surface. Large landforms have a significant impact on the climate, which varies depending on the height of the terrain and the interaction of air currents with orographic obstacles. The air temperature usually decreases with height, which leads to the formation of a cooler climate in the mountains and on the plateau than in the adjacent lowlands. In addition, hills and mountains form obstacles that force the air to rise and expand. As it expands, it cools. This cooling, called adiabatic, often results in moisture condensation and the formation of clouds and precipitation. Most of the precipitation caused by the barrier effect of mountains falls on their windward side, while the leeward side remains in the "rain shadow". Air descending on leeward slopes heats up as it compresses, creating a warm, dry wind known as a foehn.

Climate and latitude

In climatic surveys of the Earth, it is expedient to consider latitudinal zones. The distribution of climatic zones in the Northern and Southern hemispheres is symmetrical. Tropical, subtropical, temperate, subpolar and polar zones are located north and south of the equator. Baric fields and zones of prevailing winds are also symmetrical. Consequently, most climate types in one hemisphere can be found at similar latitudes in the other hemisphere.

Main types of climate

The classification of climates provides an ordered system for characterizing climate types, their zoning and mapping. Climate types that prevail over vast areas are called macroclimates. A macroclimatic region should have more or less uniform climatic conditions that distinguish it from other regions, although they are only a generalized characteristic (since there are no two places with an identical climate), more in line with realities than the allocation of climatic regions only on the basis of belonging to a certain latitude. - geographic zone.

An ice sheet climate dominates Greenland and Antarctica, where average monthly temperatures are below 0°C. During the dark winter season, these regions receive absolutely no solar radiation, although there are twilight and auroras. Even in summer, the sun's rays fall on the earth's surface at a slight angle, which reduces the heating efficiency. Most of the incoming solar radiation is reflected by the ice. In both summer and winter, low temperatures prevail in the elevated regions of the Antarctic Ice Sheet. The climate of the interior of Antarctica is much colder than the climate of the Arctic, since the southern mainland is large and high, and the Arctic Ocean moderates the climate, despite the wide distribution of pack ice. In summer, during short periods of warming, drift ice sometimes melts.

Precipitation on ice sheets falls in the form of snow or small particles of ice mist. Inland regions receive only 50-125 mm of precipitation annually, but more than 500 mm can fall on the coast. Sometimes cyclones bring clouds and snow to these areas. Snowfalls are often accompanied by strong winds that carry significant masses of snow, blowing it off the rocks. Strong katabatic winds with blizzards blow from the cold ice sheet, bringing snow to the coast.

The subpolar climate manifests itself in the tundra regions on the northern outskirts of North America and Eurasia, as well as on the Antarctic Peninsula and adjacent islands. In eastern Canada and Siberia, the southern boundary of this climatic zone runs well south of the Arctic Circle due to the strongly pronounced influence of vast land masses. This leads to long and extremely cold winters. Summers are short and cool, with average monthly temperatures rarely exceeding +10°C. To some extent, long days compensate for the short duration of summer, but in most of the territory the heat received is not enough to completely thaw the soil. Permanently frozen ground, called permafrost, inhibits plant growth and the infiltration of melt water into the ground. Therefore, in summer, flat areas turn out to be swampy. On the coast, winter temperatures are somewhat higher, and summer temperatures are somewhat lower than in the interior of the mainland. In summer, when humid air is over cold water or sea ice, fog often occurs on Arctic coasts.

The annual amount of precipitation usually does not exceed 380 mm. Most of them fall in the form of rain or snow in summer, during the passage of cyclones. On the coast, the bulk of precipitation can be brought by winter cyclones. But the low temperatures and clear weather of the cold season, characteristic of most areas with a subpolar climate, are unfavorable for significant snow accumulation.

The subarctic climate is also known as the "taiga climate" (according to the predominant type of vegetation - coniferous forests). This climatic zone covers the temperate latitudes of the Northern Hemisphere - the northern regions of North America and Eurasia, located immediately south of the subpolar climatic zone. There are sharp seasonal climatic differences due to the position of this climatic zone at fairly high latitudes in the interior of the continents. Winters are long and extremely cold, and the further north you go, the shorter the days. Summers are short and cool with long days. In winter, the period with negative temperatures is very long, and in summer the temperature can sometimes exceed +32° C. In Yakutsk, the average temperature in January is -43° C, in July - +19° C, i. the annual temperature range reaches 62 ° C. A milder climate is typical for coastal areas, such as southern Alaska or northern Scandinavia.

In most of the considered climatic zone, less than 500 mm of precipitation per year falls, and their amount is maximum on the windward coasts and minimum in the interior of Siberia. Very little snow falls in winter, snowfalls are associated with rare cyclones. Summers are usually wetter, and it rains mainly during the passage of atmospheric fronts. The coasts are often foggy and overcast. In winter, in severe frosts, icy fogs hang over the snow cover.

A humid continental climate with a short summer is characteristic of a vast band of temperate latitudes in the Northern Hemisphere. In North America, it extends from the prairies in south-central Canada to the coast of the Atlantic Ocean, and in Eurasia it covers most of Eastern Europe and parts of Central Siberia. The same type of climate is observed in the Japanese island. Hokkaido and in the south of the Far East. The main climatic features of these regions are determined by the prevailing westerly transport and the frequent passage of atmospheric fronts. In severe winters, average air temperatures can drop to -18 ° C. Summers are short and cool, with a frost-free period of less than 150 days. The annual temperature range is not as large as in the subarctic climate. In Moscow, the average January temperatures are -9 ° C, July - +18 ° C. In this climatic zone, spring frosts pose a constant threat to agriculture. In the coastal provinces of Canada, in New England and on about. Hokkaido's winters are warmer than inland areas, as easterly winds occasionally bring in warmer ocean air.

Annual rainfall ranges from less than 500 mm in the interior of the continents to over 1000 mm on the coasts. In most of the region, precipitation occurs mainly in summer, often during thunderstorms. Winter precipitation, mainly in the form of snow, is associated with the passage of fronts in cyclones. Blizzards are often observed in the rear of a cold front.

Humid continental climate with long summers. Air temperatures and the duration of the summer season increase to the south in areas of humid continental climate. This type of climate is manifested in the temperate latitudinal zone of North America from the eastern part of the Great Plains to the Atlantic coast, and in southeastern Europe - in the lower reaches of the Danube. Similar climatic conditions are also expressed in northeastern China and central Japan. Here, too, western transport predominates. The average temperature of the warmest month is +22°С (but temperatures can exceed +38°С), summer nights are warm. Winters are not as cold as in areas of humid continental climate with short summers, but temperatures sometimes drop below 0°C. January -4° C, and July - +24° C. On the coast, the annual temperature amplitudes decrease.

Most often, in a humid continental climate with a long summer, from 500 to 1100 mm of precipitation falls annually. The greatest amount of precipitation is brought by summer thunderstorms during the growing season. In winter, rains and snowfalls are mainly associated with the passage of cyclones and associated fronts.

The maritime climate of temperate latitudes is inherent in the western coasts of the continents, primarily in northwestern Europe, the central part of the Pacific coast of North America, southern Chile, southeastern Australia and New Zealand. The prevailing westerly winds blowing from the oceans have a softening effect on the course of air temperature. Winters are mild with average temperatures of the coldest month above 0°C, but when the Arctic air currents reach the coasts, there are also frosts. Summers are generally quite warm; during intrusions of continental air during the daytime, the temperature can rise to + 38 ° C for a short time. This type of climate with a small annual temperature amplitude is the most moderate among the climates of temperate latitudes. For example, in Paris, the average temperature in January is + 3 ° C, in July - + 18 ° C.

In areas of temperate maritime climate, the average annual precipitation ranges from 500 to 2500 mm. The windward slopes of the coastal mountains are the most humid. Precipitation is fairly even throughout the year in many areas, with the exception being the Pacific Northwest of the United States, which has very wet winters. Cyclones moving from the oceans bring a lot of precipitation to the western continental margins. In winter, as a rule, cloudy weather persists with light rains and occasional short-term snowfalls. Fogs are common on the coasts, especially in summer and autumn.

A humid subtropical climate is characteristic of the eastern coasts of the continents north and south of the tropics. The main distribution areas are the southeastern United States, some southeastern regions of Europe, northern India and Myanmar, eastern China and southern Japan, northeastern Argentina, Uruguay and southern Brazil, the coast of Natal in South Africa and the east coast of Australia. Summer in the humid subtropics is long and hot, with the same temperatures as in the tropics. The average temperature of the warmest month exceeds +27°C, and the maximum is +38°C. Winters are mild, with average monthly temperatures above 0°C, but occasional frosts have a detrimental effect on vegetable and citrus plantations.

In the humid subtropics, the average annual precipitation ranges from 750 to 2000 mm, the distribution of precipitation over the seasons is quite uniform. In winter, rains and rare snowfalls are brought mainly by cyclones. In summer, precipitation falls mainly in the form of thunderstorms associated with powerful inflows of warm and humid oceanic air, which are characteristic of the monsoonal circulation of East Asia. Hurricanes (or typhoons) appear in late summer and autumn, especially in the Northern Hemisphere.

A subtropical climate with dry summers is typical of the western coasts of the continents north and south of the tropics. In Southern Europe and North Africa, such climatic conditions are typical for the coasts of the Mediterranean Sea, which was the reason to call this climate also Mediterranean. The same climate is in southern California, the central regions of Chile, in the extreme south of Africa and in a number of areas in southern Australia. All these regions have hot summers and mild winters. As in the humid subtropics, there are occasional frosts in winter. In inland areas, summer temperatures are much higher than on the coasts, and often the same as in tropical deserts. In general, clear weather prevails. In summer, on the coasts near which ocean currents pass, there are often fogs. For example, in San Francisco, summers are cool, foggy, and the warmest month is September.

The maximum precipitation is associated with the passage of cyclones in winter, when the prevailing westerly air currents shift towards the equator. The influence of anticyclones and downward air currents under the oceans determine the dryness of the summer season. The average annual precipitation in a subtropical climate varies from 380 to 900 mm and reaches maximum values on the coasts and mountain slopes. In the summer, there is usually not enough rainfall for the normal growth of trees, and therefore a specific type of evergreen shrub vegetation develops there, known as maquis, chaparral, mali, machia and fynbosh.

The semi-arid climate of temperate latitudes (synonymous with the steppe climate) is characteristic mainly of inland regions remote from the oceans - sources of moisture - and usually located in the rain shadow of high mountains. The main regions with a semi-arid climate are the intermountain basins and the Great Plains of North America and the steppes of central Eurasia. Hot summers and cold winters are due to the inland position in temperate latitudes. At least one winter month has an average temperature below 0 ° C, and the average temperature of the warmest summer month exceeds + 21 ° C. The temperature regime and the duration of the frost-free period vary significantly depending on latitude.

The term "semiarid" is used to characterize this climate because it is less dry than the actual arid climate. The average annual precipitation is usually less than 500 mm but more than 250 mm. Since the development of steppe vegetation at higher temperatures requires more precipitation, the latitudinal-geographical and altitudinal position of the area is determined by climatic changes. For a semi-arid climate, there are no general regularities in the distribution of precipitation throughout the year. For example, areas bordering the subtropics with dry summers experience a maximum of precipitation in winter, while areas adjacent to areas of a humid continental climate experience rainfall mainly in summer. Mid-latitude cyclones bring most of the winter precipitation, which often falls as snow and can be accompanied by strong winds. Summer thunderstorms often come with hail. The amount of precipitation varies greatly from year to year.

The arid climate of temperate latitudes is inherent mainly in the Central Asian deserts, and in the western United States - only in small areas in intermountain basins. Temperatures are the same as in regions with a semi-arid climate, but the precipitation here is not enough for the existence of a closed natural vegetation cover and the average annual amounts usually do not exceed 250 mm. As in semi-arid climatic conditions, the amount of precipitation that determines aridity depends on the thermal regime.

The semi-arid climate of low latitudes is mainly typical of the margins of tropical deserts (for example, the Sahara and the deserts of central Australia), where descending air currents in subtropical high-pressure zones exclude precipitation. The climate under consideration differs from the semi-arid climate of temperate latitudes by very hot summers and warm winters. Average monthly temperatures are above 0°C, although frosts sometimes occur in winter, especially in areas furthest from the equator and located at high altitudes. The amount of precipitation required for the existence of dense natural herbaceous vegetation is higher here than in temperate latitudes. In the equatorial zone, it rains mainly in summer, while on the outer (northern and southern) margins of the deserts, the maximum precipitation occurs in winter. Precipitation mostly falls in the form of thunderstorms, and in winter the rains are brought by cyclones.

Arid climate of low latitudes. This is a hot dry climate of tropical deserts, stretching along the Northern and Southern tropics and being influenced by subtropical anticyclones for most of the year. Salvation from the sweltering summer heat can only be found on the coasts washed by cold ocean currents, or in the mountains. On the plains, the average summer temperatures noticeably exceed + 32 ° C, winter ones are usually above + 10 ° C.

In most of this climatic region, the average annual precipitation does not exceed 125 mm. It happens that at many meteorological stations for several years in a row precipitation is not recorded at all. Sometimes the average annual precipitation can reach 380 mm, but this is still enough only for the development of sparse desert vegetation. Occasionally, precipitation occurs in the form of short-lived heavy thunderstorms, but the water quickly drains to form flash floods. The driest regions are along the western coasts of South America and Africa, where cold ocean currents prevent cloud formation and precipitation. These coasts often have fogs formed by the condensation of moisture in the air over the colder surface of the ocean.

Average annual rainfall ranges from 750 to 2000 mm. During the summer rainy season, the intertropical convergence zone exerts a decisive influence on the climate. There are often thunderstorms here, sometimes continuous cloud cover with prolonged rains persists for a long time. Winter is dry, as subtropical anticyclones dominate this season. In some areas, rain does not fall for two to three winter months. In South Asia, the wet season coincides with the summer monsoon, which brings moisture from the Indian Ocean, and Asian continental dry air masses spread here in winter.

Humid tropical climate, or the climate of tropical rainforests, is common in the equatorial latitudes in the Amazon basin in South America and the Congo in Africa, on the Malay Peninsula and on the islands of Southeast Asia. In the humid tropics, the average temperature of any month is not less than + 17 ° С, usually the average monthly temperature is about + 26 ° С. temperatures are low. Moist air, cloudiness and dense vegetation prevent night cooling and maintain maximum daytime temperatures below +37°C, lower than at higher latitudes.

The average annual rainfall in the humid tropics ranges from 1500 to 2500 mm, the distribution over the seasons is usually fairly even. Precipitation is mainly associated with the intratropical convergence zone, which is located slightly north of the equator. Seasonal shifts of this zone to the north and south in some areas lead to the formation of two precipitation maxima during the year, separated by drier periods. Every day, thousands of thunderstorms roll over the humid tropics. In the intervals between them, the sun shines in full force.

Highland climates. In highland areas, a significant variety of climatic conditions is due to the latitudinal-geographical position, orographic barriers, and different exposure of the slopes in relation to the Sun and moisture-carrying air currents. Even at the equator in the mountains there are snowfields-migrations. The lower boundary of the eternal snows descends towards the poles, reaching sea level in the polar regions. Like it, other boundaries of high-altitude thermal belts decrease as they approach high latitudes. Windward slopes of mountain ranges receive more precipitation. On mountain slopes exposed to cold air intrusions, temperatures may drop. In general, the climate of the highlands is characterized by lower temperatures, higher cloudiness, more precipitation, and a more complex wind regime than the climate of the plains at the corresponding latitudes. The nature of seasonal changes in temperature and precipitation in the highlands is usually the same as in the adjacent plains.

climate change

Rocks, plant fossils, landforms, and glacial deposits contain information about significant fluctuations in average temperatures and precipitation over geological time. Climate change can also be studied by analyzing tree rings, alluvial deposits, ocean and lake bottom sediments, and organic peatland deposits. Over the past few million years there has been a general cooling of the climate, and now, judging by the continuous reduction of the polar ice sheets, we seem to be at the end of the ice age.

Climate change over a historical period can sometimes be reconstructed from information about famines, floods, abandoned settlements, and migrations of peoples. Continuous series of air temperature measurements are available only for meteorological stations located mainly in the Northern Hemisphere. They cover only a little over one century. These data indicate that over the past 100 years, the average temperature on the globe has increased by almost 0.5 ° C. This change did not occur smoothly, but abruptly - sharp warmings were replaced by relatively stable stages.

Experts from various fields of knowledge have proposed numerous hypotheses to explain the causes of climate change. Some believe that climatic cycles are determined by periodic fluctuations in solar activity with an interval of about 11 years. Annual and seasonal temperatures could be influenced by changes in the shape of the Earth's orbit, which led to a change in the distance between the Sun and the Earth. The Earth is currently closest to the Sun in January, but approximately 10,500 years ago it was in this position in July. According to another hypothesis, depending on the angle of inclination of the earth's axis, the amount of solar radiation entering the Earth changed, which affected the general circulation of the atmosphere. It is also possible that the polar axis of the Earth occupied a different position. If the geographic poles were at the latitude of the modern equator, then, accordingly, the climatic zones also shifted.

The so-called geographic theories explain long-term climate fluctuations by movements of the earth's crust and changes in the position of continents and oceans. In the light of global plate tectonics, continents have moved over geological time. As a result, their position in relation to the oceans, as well as in latitude, changed. In the process of mountain building, mountain systems with a cooler and, possibly, more humid climate were formed.

Air pollution also contributes to climate change. Large masses of dust and gases released into the atmosphere during volcanic eruptions occasionally became an obstacle to solar radiation and led to cooling of the earth's surface. An increase in the concentration of certain gases in the atmosphere exacerbates the overall warming trend.

The greenhouse effect. Like the glass roof of a greenhouse, many gases pass most of the thermal and light energy of the Sun to the Earth's surface, but prevent the rapid return of the heat radiated by it to the surrounding space. The main gases causing the "greenhouse" effect are water vapor and carbon dioxide, as well as methane, fluorocarbons and nitrogen oxides. Without the greenhouse effect, the temperature of the earth's surface would drop so much that the entire planet would be covered with ice. However, an excessive increase in the greenhouse effect can also be catastrophic.

Since the beginning of the industrial revolution, the amount of greenhouse gases (mainly carbon dioxide) in the atmosphere has increased due to human activities and especially the burning of fossil fuels. Many scientists now believe that the rise in global mean temperature since 1850 was mainly due to increases in atmospheric carbon dioxide and other anthropogenic greenhouse gases. If the current trends in fossil fuel use continue into the 21st century, the average global temperature could rise by 2.5-8°C by 2075. If fossil fuels are used at a faster rate than at present, such an increase in temperature could occur as early as 2030.

The projected increase in temperature could lead to the melting of the polar ice caps and most mountain glaciers, causing sea levels to rise by 30-120 cm. All of this could also affect changing weather conditions on Earth, with possible consequences such as prolonged droughts in the world's leading agricultural regions .

However, global warming as a consequence of the greenhouse effect can be slowed down if carbon dioxide emissions from burning fossil fuels are reduced. Such a reduction would require restrictions on its use throughout the world, more efficient energy consumption and the expansion of the use of alternative energy sources (for example, water, solar, wind, hydrogen, etc.).

2. Impact of volcanism on climate

.1 Volcanic areas

At present, there are 524 volcanoes on the earth's surface, showing their activity to one degree or another, including 68 underwater volcanoes. Their distribution is shown in Table 1.

Table 1. Distribution of volcanoes

Areas of distribution and areas of activity of volcanoes	Number of volcanoes
	ground	underwater
Kamchatka
Kurile Islands
about. Taiwan
At sea, 200 km. off the southeast coast of South Vietnam
Philippine Islands
Oh-wa Sangi
O. Celebes
Hall. Tomini
O. Jailolo
O. New Guinea
O. New Britain
Solomon Islands
O. Santa Cruz
O. New Hebrides
O. Loyalty
O. New Zealand
Antarctica
Southern America
O. Juan - Fernandez
Galapagos Islands
Centre. America
North America

O. Unimak
Aleutian Islands
Hawaiian Islands


O. Kermadec

Asia Minor
Mediterranean Sea

Indian Ocean without the Java Arc
Java arc
O. Jan Mayen
Iceland
Sev. Atlantic
Azores
Centre. and Yuzhn. Atlantic
West Indies

Modern volcanoes in the memory of mankind have produced over 2,500 eruptions. Extinct volcanoes, i.e. Those who have not found their activity in the history of mankind, but have retained to some extent their form and structure, are at least five to six times more than active ones.

Volcanoes are unevenly distributed. There are significantly more volcanoes in the northern hemisphere than in the southern, and they are especially common in the equatorial zone. On the continents, such regions as the European part of the USSR, Siberia (without Kamchatka), Scandinavia, Brazil, Australia and others, are almost completely devoid of volcanoes. Other areas - Kamchatka, Iceland, the islands of the Mediterranean Sea, the Indian and Pacific Oceans and the western coast of America - are very rich in volcanoes. Most volcanoes are concentrated on the coasts and islands of the Pacific Ocean (322 volcanoes, or 61.7%), where they form the so-called Pacific Ring of Fire (Fig. 22).

Volcanoes sometimes arise at the present time. For example, in 1943 in Mexico, a 10-meter cone of the new Pericutin volcano formed within a day on the field of one peasant. A year later, the height of Pericutin reached 350 m.

When looking at a map of the geographical distribution of volcanoes, attention is drawn to their confinement to islands, archipelagos and coastal zones of continents. This visibility gave rise in the last century to a false theory that considered the main cause of volcanic activity to be the access of ocean water to magma chambers through deep cracks. The followers of this hypothesis believed that when water comes into contact with molten magma, colossal masses of steam are formed, which, with their increasing pressure, produce volcanic eruptions. This hypothesis was soon refuted by numerous facts, for example, the presence of volcanoes on continents hundreds of kilometers from water basins, an insignificant content of water vapor among the gaseous emissions of some volcanoes, and so on.

At present, the dependence of volcanic activity on tectonic processes and their usual confinement to geosynclinal regions, as the most mobile zones of the earth's crust, are generally recognized. In the process of tectonic movements in these zones, deep faults, collapse, uplift and subsidence of individual blocks of the earth's crust appear, accompanied by folding, earthquakes and volcanic activity. The main areas of tectonic movements in our time are the Pacific, Mediterranean, Atlantic and Indian zones. Naturally, the vast majority of modern volcanoes are located within them.

The Pacific zone stretches from Kamchatka to the south through the islands: the Kuril, Japanese, Philippine, New Guinea, Solomon, New Hebrides and New Zealand. In the direction of the Antarctic, the "ring of fire" of the Pacific Ocean is interrupted and then continues along the western coast of America from Tierra del Fuego and Patagonia through the Andes and the Cordillera to the southern coast of Alaska and the Aleutian Islands. The volcanic group of the Sandwich Islands, Samoa, Tonga, Kermadec and Galapogos Islands is confined to the central parts of the Pacific Ocean. The Pacific ring of fire contains almost 4/5 of all the Earth's volcanoes, which have manifested themselves in more than 2000 eruptions in historical time.

The Mediterranean zone covers volcanic activity within the Alpine geosyncline from the extreme west of Europe to the southeastern end of Asia, capturing the islands of the Malay Archipelago. Within this zone, volcanic activity is most active in the marginal parts; in the west in the Mediterranean region and in the east in the Malay Archipelago. In southern and central Europe, this zone includes the extinct volcanic regions of the Auvergne (France), the Eifel (Germany) and the Czech Republic. Then come the Mediterranean volcanoes, divided into three groups: Italian-Sicilian with such famous volcanoes as Vesuvius, Etna, Stromboli, Volcano; Sicilian-Ionic, including Pantelleria and some underwater eruptions; and the Aegean, in which the Santorini volcano is the most prominent active center.

Further east, the zone includes extinct volcanoes such as Elbrus and Kazbek in the Caucasus, Ararat in Turkey, and Damavend in Iran. In the Pamirs and the Himalayas, as well as in other folded chains of southern Asia strongly compressed by cores, young volcanic activity is not observed, but young volcanoes are reappearing in Burma. Then the zone covers one of the most active areas of volcanic activity on Earth - the region of the Malay Archipelago. Here, only 11 active volcanoes are known on the islands of Sumatra, 19 on Java, 15 on the Lesser Sunda and 3 on the South Moluccas.

The Atlantic zone includes in the northern part such well-known volcanic regions as Iceland, where 26 active volcanoes are known, including 4 underwater and a very large number of extinct ones. Among the active ones, Hekla is the most active - a volcano with a height of 1557 m with five craters, which has produced about 30 eruptions in the current thousand years. To the northwest of Iceland in the Atlantic Ocean, one small active volcano is known on about. Jan Mayen. To the south, near the African coast, are the Canary Islands with several volcanoes (including Peak Tenerife) and the Cape Verde Islands with one active volcano Fogo. Northwest of the Canary Islands is a group of volcanic Azores, near which four underwater eruptions have been recorded. In the equatorial and southern parts of the Atlantic Ocean, the volcanic islands of the Gulf of Guinea, Ascension, St. Helena and Tristan da Cunha are known, although volcanic activity on them ceased long ago. The Atlantic zone of volcanism also includes Guinea on the western coast of Equatorial Africa with one active volcano, Cameroon.

The Indian zone includes three groups of volcanic islands in the Indian Ocean: Comorian with the Karatala volcano, Mascarene with the Piton de la Fournaise volcano, and Kergen with an active volcano on about. Hurd. The largest in the last group about. Kergen is composed of shield covers of basalt and can be considered as a twin of about. Iceland in the Indian Ocean. The Indian zone of volcanoes also includes the volcanoes of East Africa and signs of young volcanic activity on the Arabian Peninsula and in Asia Minor. The volcanoes of East Africa seem to be associated with a system of deep tectonic fissures and narrow subsidence areas extended along them, which stretch from the Red Sea through Kenya and Tanganyika to the coast of the Mozambique Channel.

Rice. 2.1. - Map of the distribution of volcanoes.

Climatic effects of volcanic activity

Most noticeably, the climatic effects of eruptions affect changes in surface air temperature and the formation of meteoric precipitation, which most fully characterize climate-forming processes.

temperature effect. Volcanic ash thrown into the atmosphere during explosive eruptions reflects solar radiation, lowering the air temperature on the Earth's surface. While the stay of fine dust in the atmosphere from a Vulcan-type eruption is usually measured in weeks and months, volatiles such as SO 2 can remain in the upper atmosphere for several years. Small particles of silicate dust and sulfur aerosol, concentrating in the stratosphere, increase the optical thickness of the aerosol layer, which leads to a decrease in temperature on the Earth's surface.

As a result of the eruptions of volcanoes Agung (Bali, 1963) and St. Helens (USA, 1980), the observed maximum decrease in the temperature of the Earth's surface in the Northern Hemisphere was less than 0.1 °C. However, for larger eruptions, such as Tambora Volcano (Indonesia, 1815), a temperature drop of 0.5 °C or more is quite possible.

During the largest eruptions, similar to those observed at the Tambora volcano, the amount of solar radiation passing through the stratosphere is reduced by about a quarter. Giant eruptions like the one that created a layer of tephra (Toba Volcano, Indonesia, about 75,000 years ago) could reduce the penetration of sunlight to less than a hundredth of its norm, which prevents photosynthesis. This eruption is one of the largest in the Pleistocene, and the fine dust ejected into the stratosphere appears to have resulted in near-universal darkness over a wide area for weeks and months. Then, in about 9-14 days, about 1000 km 3 of magma was erupted, and the distribution area of the ash layer exceeded at least 5⋅106 km 2 .

Another reason for possible cooling is due to the shielding effect of H 2 SO 4 aerosols in the stratosphere. Following, we assume that in the modern era, as a result of volcanic and fumarolic activity, approximately 14 million tons of sulfur enter the atmosphere annually, with its total natural emission of approximately 14.28 million tons. oxides in H 2 SO 4 (assuming this value remains unchanged over the considered time interval) approaches the minimum estimate of the direct input of aerosols in the form of sulfuric acid into the stratosphere due to the eruption of the Toba volcano. Most of the sulfur oxides immediately enter the ocean, forming sulfates, and a certain proportion of sulfur-containing gases is removed by dry absorption or washed out of the troposphere by precipitation. Therefore, it is obvious that the eruption of the Toba volcano led to a multiple increase in the amount of long-lived aerosols in the stratosphere. Apparently, the cooling effect manifested itself most clearly in low latitudes, especially in adjacent latitudes. Estimates of the amount of solar radiation penetrating through stratospheric aerosol and/or fine dust veil, depending on their mass. Dots indicate major historical and prehistoric eruptions.

Acidity time series for the Crete core of central Greenland isolds covering the period 533-1972. Identification of eruptions, most likely corresponding to the largest peaks of acidity, is based on historical sources in the regions - India, Malaysia. The global significance of this phenomenon is also indicated by the "sour" trace of the Toba volcano, recorded at depths of 1033 and 1035 m in the core of wells 3G and 4G at Vostok station in Antarctica.

Evidence of volcanic climate modulation over decades has also been obtained from the study of tree rings and changes in the volume of mountain glaciers. The paper shows that frost periods in the western United States, established using tree-ring dendrochronology, are in close agreement with recorded eruptions and can probably be associated with a haze of volcanic aerosols in the stratosphere on the scales of one or two hemispheres. L. Scuderi noted that there is a close relationship between the different thickness of the rings at the upper boundary of the growth of forests that are sensitive to temperature changes, the acidity profiles of the Greenland ice and the advance of the mountain glaciers of the Sierra Nevada (California). A sharp decrease in tree growth was observed during the year following the eruption (which resulted in the formation of an aerosol sheet), and a decrease in the growth of rings occurred within 13 years after the eruption.

The most promising sources of information about past volcanic aerosols are, however, ice core acidity and sulfate (acid) series, because they contain material evidence of atmospheric loading of chemical impurities. Since ice can be dated on the basis of its annual accumulation, it is possible to directly correlate acidity peaks in the upper layers of ice with historical eruptions of a known period. Using this approach, early acidity peaks of unknown origin are also correlated with a certain age. Apparently, such powerful eruptions in the Holocene as unknown events that took place in 536-537 years. and around 50 BC, or Tambora in 1815, led to a clear decrease in solar radiation and cooling of the planet's surface for one to two years, which is confirmed by historical evidence.

At the same time, the analysis of temperature data suggested that the warming in the Holocene in general and in the 1920s–1930s in particular was due to a decrease in volcanic activity.

Considering the possible impact on the climate of eruptions, primarily low-latitude volcanoes, or summer eruptions in temperate or high latitudes, it is necessary to take into account the type of volcanic material. Otherwise, this may lead to a multiple overestimation of the thermal effect. Thus, during explosive eruptions with a dacitic type of magma (for example, the St. Helens volcano), the specific contribution to the formation of H 2 SO 4 aerosols was almost 6 times less than during the Krakatoa eruption, when about 10 km 3 of andesitic magma was ejected and about 50 million tons of H 2 SO 4 aerosols were formed. In terms of the effect of atmospheric pollution, this corresponds to an explosion of bombs with a total capacity of 500 Mt and, according to, should have significant consequences for the regional climate.

Basaltic volcanic eruptions bring even more sulfur-containing exhalations. Thus, the basalt eruption of Laki in Iceland (1783) with a volume of erupted lava of 12 km 3 led to the production of approximately 100 million tons of H 2 SO 4 aerosols, which is almost twice the specific production of the Krakatau explosive eruption. The eruption of Laki, apparently, to some extent caused a cooling at the end of the 18th century. in Iceland and Europe. Based on the acidity profiles of ice cores in Greenland, which reflect volcanic activity, it can be noted that volcanic activity in the Northern Hemisphere during the Little Ice Age correlates with general cooling.

The role of volcanic activity in the formation of precipitation. A common belief is that in the formation of atmospheric precipitation, the primary process under natural conditions at any temperature is the condensation of water vapor, and only then ice particles appear. Later it was shown that even with repeated saturation, ice crystals in perfectly clean moist air always arise due to the homogeneous appearance of droplets with subsequent freezing, and not directly from the vapor. It was experimentally determined that the rate of nucleation of ice crystals in supercooled water drops under homogeneous conditions is a function of the volume of the supercooled liquid, and it is the lower, the smaller this volume is: drops with a diameter of several millimeters (rain) are cooled to a temperature of -34 before freezing. -35 °C, and a few microns in diameter (cloudy) - up to -40 °C. Usually, the temperature of formation of ice particles in atmospheric clouds is much higher, which is explained by the heterogeneity of the processes of condensation and crystal formation in the atmosphere due to the participation of aerosols.

During the formation of ice crystals and their accumulation, only a small part of aerosol particles serve as ice-forming nuclei, which often leads to overcooling of clouds to -20 °C and below. Aerosol particles can initiate the formation of an ice phase both from supercooled liquid water by freezing droplets from the inside, and by sublimation. A study of sublimated snow crystals collected in the Northern Hemisphere showed that in about 95% of cases, one hard core was found in their central part (mainly 0.4-1 microns in size, consisting of clay particles). At the same time, clay particles and volcanic ash are most effective in the formation of ice crystals, while sea salts prevail in cloud drops.

Such a difference may be important in explaining the higher rates of snow accumulation in the high latitudes of the Northern Hemisphere (compared to the Southern Hemisphere), as well as the greater efficiency of cyclonic transport of atmospheric moisture over Greenland than over Antarctica.

This partly "explains" the cooling in the Early Dryas, which manifested itself most clearly in the North Atlantic basin approximately 11-10 thousand years ago. The beginning of this cooling could have been initiated by a sharp increase in volcanic activity in the period 14-10.5 thousand years ago, which was reflected in a multiple increase in the concentration of volcanogenic chlorine and sulfates in the ice cores of Greenland.

In areas adjacent to the North Atlantic, this cooling may be associated with large eruptions of the Ice Peak (11.2 thousand years ago) and Eifel volcanoes in the Alps (12-10 thousand years ago). The cooling extremum is in good agreement with the eruption of the Vedde volcano 10.6 thousand years ago, the ash layer of which can be traced in the northeast Atlantic. Directly for the period of 12-10 thousand years ago. there is also a maximum of nitrates, the decrease in the concentration of which coincides with the beginning of warming after the extreme of cooling (10.4 thousand years ago). In the Southern Hemisphere, as is known, the Early Dryas is not marked by a decrease in the CO2 content in the Antarctic ice cores and is weakly expressed in the climatic curves, which is consistent with lower concentrations of volcanogenic aerosols than in Greenland. On the basis of the foregoing, a preliminary conclusion can be drawn that volcanic activity, in addition to direct impact on climate, manifests itself in imitation of an “additional” cooling due to increased snowfall.

.2 Kamchatka-Kuril

The volcanoes of Kamchatka are closely connected with the mountain-building movements of the earth's crust, in particular, with the formation of ridges, which gives a special character to the relief of the Kamchatka Peninsula.

Two mountain ranges and a chain of various volcanoes stretch along the peninsula.

In the western half is the Sredinny Ridge. The East Kamchatka Range runs in the eastern half. Different parts of this ridge have different names. The southern part is Yuzhno-Bystrinsky, at the turn to the northeast - Ganalsky vostryaki, further to the northeast - the Valaginsky ridge, even further - the Tum-rok ridge and, finally, from Klyuchevskoy Dol to the north-northeast, the Kumroch ridge, which ends at Lake Bay.

A chain of volcanoes, forming a kind of a kind of ridge, is located along the eastern coast of the peninsula, from Cape Lopatka to Lake Kronotskoye. Further, as if crossing the Tumrok ridge, this chain goes straight to the north, but already along the western slopes of the Tumrok and Kumroch ridges.

The ridges and chain of volcanoes in Kamchatka have a northeasterly direction. But, in addition, some volcanoes and hot spring outlets are located along the lines of the northwest direction. Such their location is associated with the geological structure of the earth's crust, with the faults of the Kamchatka-Kuril and Aleutian volcanic and tectonic arcs included in the Pacific fiery volcanic ring.

Volcanic activity in Kamchatka began before the Mesozoic, and perhaps even before the Paleozoic, and it resumed four times before the Mesozoic.

Volcanic activity in the first, most ancient, stage was not intense. It was accompanied by small outpourings of lava. On the other hand, the second and third stages Volcanic activity was accompanied by powerful massive outpourings of lavas, and in the second stage the lavas poured out under water.

The lavas that erupted during all these stages had a basic composition. In the Mesozoic period, i.e. Approximately 190-70 million years ago, volcanic activity in Kamchatka resumed at least twice, and for the first time there were minor underwater outpourings of lavas of the main magma. For the second time, about 70 million years ago, on the border of the Cretaceous and Tertiary periods, volcanic activity assumed grandiose proportions. Surface and underwater eruptions of basaltic and basaltic andesite lavas alternated with strong explosive activity, which resulted in the formation of large accumulations of volcanic tuff breccias and tuffs.

The eruptions originated mainly from numerous small fissures and central volcanoes and somewhat resembled modern volcanic activity on the Kuril Islands. The eruptions were very intense, and their lavas and tuffs occupied a large area. This volcanic activity continued during the Upper Cretaceous and at the beginning of the Lower Tertiary, i.e. about 80-60 million years ago.

The resumption of volcanic activity occurred in the Upper Tertiary time, i.e. about 20-10 million or less years ago. Both basic and especially medium and acidic lavas were poured out.

Finally, the last resumption of volcanic activity, which continues to the present, occurred about 1 million years ago, at the beginning of the Quaternary.

Thus, volcanic activity in Kamchatka probably began before the Paleozoic and has not yet ended at the present time. Her manifestations either intensified or weakened. It was connected and took place almost simultaneously with the mountain-building movements of the earth's crust in Kamchatka.

Modern volcanic activity, which began at the end of the Kamchatka glaciation, is much weaker compared to the intense and powerful activity of past times.

Numerous active and extinct volcanoes and volcanic rocks, which cover more than 40% of its surface, testify to the total power of volcanic activity in Kamchatka for a lifetime.

Of the features of Kamchatka, it should be noted the mobility of the earth's crust, especially in its eastern regions. These areas are places of quite strong, often repeated volcanic and tectonic earthquakes. They belong to 7-, 8-, and 9-magnitude earthquake zones. The mobility of Kamchatka, in addition to frequent earthquakes, is also evidenced by terraces and other geological data. According to them, one can judge that the eastern part of Kamchatka moves differently. While north of the Kamchatka River, the coast of the peninsula has risen significantly after glaciation, in the middle part of the peninsula - near the Semyachik River - it has risen only by an insignificant amount, and in the southern part - near Petropavlovsk and further south - the coast is slowly lowering.

All these data taken together emphasize the special uneven mobility of the eastern regions of Kamchatka. It is not surprising, therefore, that the currently active volcanoes are located only in the eastern part of the peninsula, although there are indications that there is one active volcano in the Sredinny Range - Ichinsky, which is currently emitting jets of gases. However, this indication has not been confirmed and is therefore doubtful.

Volcanoes in Kamchatka are located in three strips - along the eastern coast, along the Sredinny Range and along the western coast. Their volcanic activity was diverse both in terms of types of volcanic activity and forms of volcanoes, and in terms of the composition of lavas.

Relatively recently (in the Tertiary), basalts poured out through numerous closely spaced cracks or tubular channels and formed extensive covers resembling covers of mass eruptions. Such outpourings were then replaced only by central eruptions, which are observed at the present time. Depending on the composition of the lavas and the type of volcanic activity, as well as a number of other reasons, various volcanoes arose above the central channels. Almost all types of volcanic activity are known in Kamchatka, with the exception of Plinian and, perhaps, Hawaiian. However, the latter, i.e. eruptions of the Hawaiian type may have occurred here in the recent past.

Modern volcanic activity is concentrated in the eastern part of the Kamchatka Peninsula. All active, all attenuated and most of the extinct volcanoes are located here. However, among the latter, perhaps, there are not extinct, but soundly sleeping volcanoes that can wake up and begin to act.

Of the active volcanoes, the most active are Klyuchevskoy, Karymsky and Avachinsky; less active - Sheveluch, Plosky Tolbachik, Gorely Ridge and Mutnovsky; and inactive ones - Kizimen, Maly Semya-chek, Zhupanovsky, Koryaksky, Ksudach and Ilyinsky.

active volcanoes

In Kamchatka, among the active volcanoes, there are volcanoes that are diverse in their activity, type of activity, shape and composition.

The most active include: Klyuchevskoy volcano (34 cycles of eruptions), Karymsky (16 cycles) and Avachinsky (16 cycles).

Active - Sheveluch, Gorely Ridge and Mutnovsky (6 cycles each), Plosky Tolbachik (5 cycles), and weakly active Zhupanovsky (4 cycles), Maly Semyachik (3 cycles), Koryaka, Ksudach, Ilyinsky and Kizimen (one each eruption for everyone).

Of these, to the Strombolian type volcanic activities include Klyuchevskoy; to the volcano Klyuchevskoy, Karymsky, Avachinsky, Sheveluch, Gorely Ridge, Mutnovsky, Zhupanovsky, Ksudach; to the intermediate Hawaiian-Strombolian Plosky Tolbachik; to a type close to Peleian, Avachinsky, Sheveluch; to the Bandaisan one, some eruptions of Ilyinsky and Maly Semyachik.

At present, characteristic manifestations of the Hawaiian type of volcanic activity are not observed, but they probably occurred in Kamchatka in the recent past on Plosky Tolbachik.

Klyuchevskoy volcano is one of the greatest active volcanoes in Europe and Asia and the highest and most active volcano in Kamchatka. It is inferior in absolute height only to some active volcanoes in Central and South America. In terms of relative height, Klyuchevskoy volcano, which rises almost from sea level, is one of the highest active volcanoes on the earth's surface. Its absolute height, according to various authors, ranges from 4778-4917 m. Due to its height and regular conical shape, as well as the almost constant manifestation of volcanic activity, Klyuchevskoy volcano is one of the most beautiful volcanoes in the world.

It is located in the northeastern corner of the so-called Klyuchevskaya group of volcanoes, consisting of active Klyuchevskoy and Plosky Tolbachik and extinct - Plosky, Sredny, Kamen, Bezymyanny, Zimin, Bolshaya Udina, Malaya Udina and Ostroy Tolbachik. This group of giants, with a height of 2000 m and above, is headed by three giants - the three highest volcanoes of Kamchatka - Klyuchevskoy, about 4800 m high, Kamen 4617 m and Plosky 4030 m. All of them are located in a wide valley between the Kumroch and Sredinny ridges. Klyuchevskoy volcano is located on the eastern slope of the foot of Plosky volcano. From the top to a height of about 2,800 m, Klyuchevskoy Volcano has the shape of a slightly truncated cone, somewhat disturbed by an incandescent avalanche during the eruption on January 1, 1945, which formed a deep and wide rut near the top. The slopes of the cone are inclined to the horizon at an angle of 33 35°. With the exception of the bridge connecting Klyuchevskoy volcano with Kamen, and the ice divide connecting Klyuchevskoy volcano with Ploskoy, in other parts of the volcano, from 2700 to 1500 m of absolute height, the slope becomes more gentle, about 10-12 ° to the horizon. Below 1500 m and up to the level of the valleys of the Kamchatka and Khapitsa rivers surrounding Klyuchevskoy volcano lies the foot of the volcano, the general slope of which is about 4°.

At the top of the cone of Klyuchevskoy volcano there is a bowl-shaped crater, about 500 m in diameter, which, due to frequent eruptions, sometimes changes its shape somewhat. The edges of the crater are jagged and, in addition, have significant indentations, both on the eastern and western sides. After the eruption of 1937, the western excavation expanded significantly and took on a bucket-like shape, and after the eruption on January 1, 1945, deep (up to 200 m deep) “gates” formed in its northern part.

One or two vents were observed inside the crater during quieter times. During a more active state of the volcano, an inner cone usually grew in the crater, which rose above its original edges. The walls of the crater are composed of alternating layers of lava, volcanic sand and ice mixed with sand.

The slopes of the cone are covered with an almost continuous glacier, among which here and there are ridges - the upper parts of lava flows. Glaciers descend to a height of 2,000 - 1,800 m and one, flowing to the north, is the most powerful, up to 1,500 m.

Numerous streams flow from under the glaciers, which, connecting into larger rivers, flow as if along radii along the northeastern and eastern slopes of the foot of the volcano. In many cases, they cut deep gorges - canyons - in volcanic rocks.

In addition, the slopes of the foot of Klyuchevskoy volcano are strewn with secondary cones, the maximum relative height of which reaches 200 m. Most of them are belted along radii extending from the main crater as from the center. At the same time, many side cones are approximately at the same height. Apparently, most of them are located along radial and, perhaps, circular cracks. The predominant part of the side cones was formed as a result of explosive activity, and they consist of volcanic sand and pieces of slag. The formation of some cones was accompanied by an outpouring of lava.

Side cones are located at distances from 8 to 25 km from the main crater.

Lava flows from Klyuchevskoy Volcano erupted both from the main crater and mainly from low-lying side cones. In their form, lava flows have much in common with glaciers. The same system of transverse fissures appears, especially on the steeper slopes of the underlying terrain. There are also longitudinal lava ridges, similar to longitudinal moraines, etc. .

Rice. 2.2. - Eruption of the Karymsky volcano (January 1996, Ya.D. Muravyov)

fading volcanoes

Volcanoes after their origin change, undergo a whole series of transformations, either collapsing or re-emerging, but they live only as long as there is a sufficient amount of volcanic energy in their volcanic foci.

With its decrease, the life of the volcano begins to die, its activity gradually dies. He falls asleep. When the energy is completely exhausted, the volcano stops all activity, its active life ends. The volcano is dead.

Attenuated volcanoes, which are currently in the solfataric stage of activity, are located mainly near Lake Kronotskoye. To the northeast of it are the Komarov and Gamchen volcanoes, to the east - Kronotsky, and to the south there is a whole group of such volcanoes Uzon, Kikhpinych, Yaurlyashchy and Proper - Central Semyachik.

Volcano Komarov (Reserved) has a cap-shaped form. It has two craters, one of which is located on the summit, the other is on the southwestern slope near the summit.

In the latter there is a recess through which the outpouring of lava occurred. Lava flows spread widely along the southern and eastern slopes.

At present, jets of gases are emitted from the crater, and especially intensively and almost continuously - from its western part of the crater. In April 1941, gas jets rose up to 200 m above the crater.

As a result of the action of gases, consisting of hydrogen sulfide and, perhaps, sulfur dioxide and, of course, water vapor, on the rocks of the eastern part of the crater, they turned into light gray, mostly clay or alunite rocks.

Thus, volcanoes in Kamchatka are among the fading ones, in the solfataric stage of them, the most active solfataric stage are: Uzon, Burlyashchiy and the Central Semyachik itself. The least active, almost completely extinct, belong to the Kronotsky volcano and Opala. The rest occupy an intermediate position between them in terms of their activity.

Extinct volcanoes

Compared to the number of active and dying volcanoes, the number of extinct volcanoes is much greater.

They are located not only in the eastern strip of the peninsula and in the Sredinny Range, but also partially along the western coast of the Kamchatka Peninsula.

Among the extinct volcanoes are those that acted in the recent past, and those that ended their lives in more distant times. The former are recognized by the unaltered appearance of volcanoes, by fresh lava flows, not yet covered with vegetation in lower places, but with mosses in higher ones, and by a number of other signs.

Among the recently extinct volcanoes are Bezymyanny, Krashevinnikova, Taunshits, Yuryevsky and some others. Among the extinct volcanoes, the Kamen and Plosky volcanoes are the highest, but different in their form and in their volcanic life.

Volcanoes of the Kuril Islands

The Kuril Islands are two large ridges of islands: the Greater Kuril and the Lesser Kuril.

A large ridge "stretches for" 1,200 km directly from the Kamchatka Peninsula to the southwest to the island of Hokkaido.

The Small Ridge stretches for 105 km and runs parallel to the southern part of the Greater Kuril Ridge, 50 km southeast of it.

Volcanoes are located almost exclusively on the islands of the Greater Kuril Ridge. Most of these islands are active or extinct volcanoes, and only the northernmost and southernmost islands are composed of Upper Tertiary sedimentary formations.

These layers of sedimentary rocks on the mentioned islands were the foundation on which volcanoes arose and grew. Most of the volcanoes of the Kuril Islands arose directly on the seabed.

The relief of the seabed between the Kamchatka Peninsula and the island of Hokkaido is a steep ridge with bottom depths of about 2,000 m towards the Sea of Okhotsk, and near the island of Hokkaido even more than 3,300 m and with depths of more than 8,500 m towards the Pacific Ocean. As you know, directly southeast of the Kuril Islands is one of the deepest oceanic depressions, the so-called Tuscarora depression.

The Kuril Islands themselves are the peaks and ridges of a solid mountain range hidden still under water.

The Great Kuril Ridge is a remarkable and vivid example of the formation of a ridge on the earth's surface. Here you can observe the bend of the earth's crust, the crest of which rises 2-3 km above the bottom of the Sea of Okhotsk and 8-8.5 km above the Tuskarora depression. Faults formed at this bend along its entire length, along which fiery-liquid lava broke through in many places. It was in these places that the volcanic islands of the Kuril ridge arose. Volcanoes poured out lava, threw out a mass of volcanic sand and debris that settled nearby in the sea, and it became and becomes smaller and smaller. In addition, and the very bottom of the force can rise for various geological reasons, and if such a geological process continues in the same direction, then in millions of years, and perhaps in hundreds of thousands, a continuous ridge will form here, which, on the one hand, will connect Kamchatka with Hokkaido, and on the other - will completely separate the Sea of Okhotsk from the Pacific Ocean.

The emergence of the Kuril ridge helps us understand the formation of other ridges that now rise entirely on land. In this way, the Ural Range and a number of others once arose.

Among the Devonian Sea, which at that time (about 300 million years ago) covered the area where the Ural Range is now located, cracks-faults arose on a similar bend of the earth's underwater surface, along which magma rose from the depths. Its underwater eruptions, as lavas accumulated from the bottom of the sea to the surface of the water, were replaced by surface volcanoes, which formed the islands, i.e. The result is the same picture that is now observed on the border of the Sea of Okhotsk with the Pacific Ocean. The volcanoes of the Urals, along with outpourings of lavas, also threw out a mass of detrital volcanic material that settled nearby. Thus, the volcanic islands were connected to each other. This unification was helped, of course, by the movements of the earth's crust and some other processes, as a result of the total impact of which the Ural mountain range arose.

The volcanoes of the Kuril ridge are located on arcuate faults, which are a continuation of the faults of Kamchatka. Thus, they form one volcanic and tectonic Kamchatka-Kuril arc, convex towards the Pacific Ocean and directed, in general, from the southwest to the northeast.

The relief of all the islands, with the exception of the northernmost one, is mountainous.

The activity of volcanoes on the Kuril Islands in the past and at present is very intense. There are about 100 volcanoes here, of which 38 are active and are in the solfataric stage of activity.

Initially, volcanoes arose in the Upper Tertiary on the extreme southwestern and northeastern islands of the Kuril chain, and then they moved to its central part. Thus, volcanic life on them began quite recently, only one or a few million years, and continues to this day.

Information about volcanic eruptions of the Kuril ridge has been available since the beginning of the 18th century, but they are very fragmentary and far from complete.

active volcanoes

21 active volcanoes are known on the Kuril Islands, of which five stand out for their more active activity, among the most active volcanoes of the Kuril ridge, these include Alaid, Sarychev Peak, Fuss, Snow and Milna.

Among the active volcanoes of the Kuril Islands, the most active volcano is Alaid. It is also the highest among all the volcanoes of this ridge. As a beautiful cone-shaped mountain, it rises directly from the sea surface to a height of 2,339 m. At the top of the volcano there is a small depression, in the middle of which the central cone rises.

It erupted in 1770, 1789, 1790, 1793, 1828, 1829, 1843 and 1858, i.e. eight eruptions in the last 180 years.

In addition, near the northeastern shores of Alaid, an underwater eruption occurred in 1932, and in December 1933 and January 1934, eruptions occurred 2 km from its eastern shore. As a result of the last eruption, a volcanic island with a wide crater was formed, called Taketomi. It is a side cone of the Alaid volcano. Taking into account all these eruptions, we can say that over the past 180 years, at least 10 eruptions have occurred from the Alaid volcanic chamber.

In 1936, a spit formed between Taketomi and Alaid volcanoes, which connected them. The lavas and loose volcanic products of Alaida and Taketomi are basaltic.

Sarychev Peak ranks second in intensity of volcanic activity and is a stratovolcano, located on the island of Matua. It has the form of a two-headed cone with a gentle slope in the lower part and with a steeper one - up to 45 °, in the upper part.

On the higher (1497 m) peak there is a crater with a diameter of about 250 m and a depth of about 100 - 150 m. There are many cracks near the crater on the outer side of the cone, from which white vapors and gases were emitted (August and September 1946).

From the 60s of the XVIII century to the present, its eruptions occurred in 1767, around 1770, around 1780, in 1878-1879, 1928, 1930 and 1946. In addition, there are numerous data on its fumarole activity. So in 1805, 1811, 1850, 1860. he "smoked". In 1924, an underwater eruption occurred near it.

Thus, over the past 180 years, there have been at least seven eruptions. They were accompanied by both explosive activity and outpourings of basaltic lava.

The last eruption occurred in November 1946. This eruption was preceded by a revival of activity of the neighboring volcano Rasshua, located on the island of the same name. On November 4, it began to rapidly emit gases, and a glow was visible at night, and from November 7, an increased release of white gases from the crater of the Sarychev Peak volcano began.

November at 17 o'clock a column of gases and black ash rose above its crater, and in the evening a glow appeared, which was visible all night. During November 10, ash was thrown out of the volcano and light, but frequent tremors occurred, and an uninterrupted underground rumble was heard, and occasionally thunder peals.

On the night of November 11-12, mainly hot bombs were thrown to a height of up to 100 m, which, falling along the slopes of the volcano, cooled rather quickly. From 22:00 12 to 14 November, the eruption reached its maximum stress. First, a huge glow appeared over the crater, the height of the flight of volcanic bombs reached 200 m, the height of the gas-ash column - 7000 m above the crater. Particularly deafening explosions occurred on the night of the 12th to the 13th and on the morning of November 13th. On November 13, the outpouring of lava began, and side craters formed on the slope.

The eruption was especially beautiful and spectacular on the night of November 13 and 14. Fiery tongues descended from the crater down the slope.

The entire top of the volcano, 500 m down from the crater, seemed red-hot from a large amount of ejected bombs, debris and sand.

From the morning of November 13 to 2 pm on November 14, the eruption was accompanied by various types of lightning, which almost every minute sparkled in different directions.

Fussa Peak Volcano located on the island of Paramushir and is a separate beautiful gkonus, the western slopes of which abruptly break into the Sea of Okhotsk.

Fuss Peak erupted in 1737, 1742, 1793, 1854 and H859, with the last eruption, i.e. 1859, was accompanied by the release of asphyxiating gases.

Snow Volcano is a small low domed volcano, about 400 m high, located on Chirpoy Island (Black Brothers Islands). At its top (there is a crater about 300 m in diameter. In the northern part of the bottom of the crater there is a depression in the form of a well, with a diameter of about 150 m. Numerous lava flows poured out mainly to the south of the crater. Apparently, it belongs to the thyroid volcanoes. An indication without an exact date is known about the eruption of this volcano in the 18th century. In addition, Snow volcano erupted in 1854, 1857, 1859 and 1879. Volcano Milne located on Simushir Island, it is a two-headed volcano with an inner cone 1,526 m high and parts of the ridge bordering on the western side - the remains of a destroyed more ancient volcano, 1,489 m high. Lava flows are visible on the slopes, which in places protrude into the sea in the form of huge lava fields.

There are several side cones on the slopes, of which one, called the "Burning Hill", acts along with the main cone and, thus, is, as it were, an independent volcano.

There is information about the volcanic activity of the Milna volcano dating back to the 18th century. According to more accurate information, it erupted in 1849, 1881 and 1914. Some of them, in all likelihood, refer only to the eruptions of the Burning Hill.

Less active volcanoes include the Severgin, Sinarka, Raikoke, and Medvezhiy volcanoes.

underwater volcanoes

In addition to active terrestrial volcanoes, there are active underwater volcanoes near the Kuril Islands. These include: underwater volcanoes located to the northeast of Alaid Island, which erupted in 1856 and 1932; west of Stone Traps Island, which erupted in 1924; an underwater volcano located between the islands of Rasshua and Ushishir and erupted in the 80s of the last century, and, finally, an underwater volcano located directly south of the island of Simushir, which erupted in 1918.

fading volcanoes

Attenuated volcanoes, which are in the solfataric stage of activity, are located mainly in the southern half of the Kuril chain. Only the intensely smoking volcano Chikurachki , 1,817 m high, located on Paramushir Island, and Ushishir Volcano , located on the island of the same name, are located in the northern half of the ridge, the latter being located near the beginning of its southern part.

Volcano Ushishir (400 m). The edges of its crater form a ring-shaped ridge, destroyed only on the south side, due to which the bottom of the crater is filled with sea.

Volcano Black (625 m) is located on the Black Brothers Island. It has two craters: one at the top, about 800 m in diameter, and the other crack-shaped on the southwestern slope. Thick clouds of vapors and gases stand out along the edges of the latter.

Extinct volcanoes

There are many extinct volcanoes of various shapes on the Kuril Islands - cone-shaped, dome-shaped, volcanic massifs, a type of volcano in a volcano, etc.

Among the cones volcanoes stands out for its beauty Atsonupuri, 1,206 m high. It is located on the island of Iturup and is a regular cone; on its top there is an oval-shaped crater, about 150 m deep. A well-preserved lava flow descends along the slope facing the sea.

Volcanoes also belong to cone-shaped volcanoes: Aka (598 m) on the island of Shiashkotan; Roko (153 m), located on the island of the same name near Brat Chirpoev Island (Black Brothers Islands); Rudakova (543 m) with a lake in the crater, located on the island of Urup, and Bogdan Khmelnitsky volcano (1,587 m), located on the island of Iturup.

domed Shestakov volcanoes have a shape (708 m), located on the island of Onekotan, and Broughton - 801 m high, located on the island of the same name. On the slopes of the last volcano there are small cone-shaped elevations, probably side cones.

Volcanic massifs include Ketoi volcano - 1,172 m high, located on the island of the same name, and Kamuy volcano - 1,322 m high, located in the northern part of Iturup Island.

To the type of "volcano in a volcano" relate:

Krenitsyn Peak on Onekotan Island , the inner cone of which, 1,326 m high, is surrounded by a beautiful lake that fills the depression between it (the inner cone) and the remains of the original outer cone, now rising from 600 to 960 m above sea level.

.3 Iceland

Almost the entire territory of Iceland is a volcanic plateau with peaks up to two kilometers, many of them abruptly break off to the ocean, due to which they form fjords - narrow, winding sea bays with rocky shores. Numerous active volcanoes, geysers, hot springs, lava fields and glaciers - this is Iceland. By their number per unit area, the country confidently ranks first in the world. The “Icelandic Fuji” of Hekla and the colorful Kverkfjöll, the giant fissure of the Lucky volcano and Helgafell on the island of Heimaey, which almost turned the once prosperous port of Vestmannaeyjar into the “Icelandic Pompeii”, the most picturesque Graubok and the “creator of the islands” Syurtsey, as well as many tens and hundreds of volcanic cracks and calderas, extinct and mud volcanoes and volcanoes - these are the "titans" that literally created Iceland.

In April of this year, the whole world was busy memorizing a previously unknown word: "Eyyafyatlayokudl." Only the lazy did not memorize this set of sounds, unusual for Russians. Eyyafyatlayokudl is a wonderful Icelandic volcano that almost completely paralyzed air traffic in Europe. The ash cloud rose to a height of about 6-10 kilometers and spread to the territory of Great Britain, Denmark and the Scandinavian countries and the countries of the Baltic region. The appearance of ash was not long in coming in Russia - in the vicinity of St. Petersburg, Murmansk and a number of other cities. The volcanic eruption, which is located 200 kilometers from the capital of Iceland, Reykjavik, began on the night of April 14, 2010. 800 people were evacuated from the disaster area.

The volcanoes of Iceland are of the so-called fissure type. This means that the eruption does not come from a single crater, but from a crack, that is, in fact, a chain of craters. Therefore, their impact on the climate and the inhabitants of the Earth is much larger and more long-term than that of central-type volcanoes - with one or more craters - even if they are very powerful, such as Etna, Vesuvius, Krakatoa, etc.

The Icelandic volcano Laki in 1783 had such a detrimental effect on the climate that it caused more deaths. Within 7 months, a huge amount of fluorites (salts of hydrofluoric acid) and sulfur dioxide were ejected from a 25 km long crack. Acid rains and a giant cloud of volcanic dust that hung over the whole of Eurasia and parts of the African and North American continents caused such climate changes that led to crop failures, livestock deaths and mass starvation - not only in Iceland, but also in other countries of Europe and even in Egypt. As a result, the population of Ireland decreased by a quarter, and the population of Egypt - by 6 times. Crop failures and famine years that followed the eruption contributed to the growth of social discontent.

In ancient times, Icelandic volcanoes erupted on an even larger scale. According to scientists, they could cause the extinction of mammoths and related groups of animals, as well as the death of forests in Iceland.

The volcano, which caused so much trouble throughout Europe, is 50 times smaller than Lucky - it is a crack "only" 500 m away. It does not even have its own name and is named after the glacier under which it is located. However, even with such a modest size, he has already sowed real panic. Scientists remind that the previous eruptions of this volcano always preceded the eruptions of another subglacial volcano Katla, which is more active. If this happens again, the consequences could be dire.

Askja is an active stratovolcano in the central Icelandic plateau, located above the lava plateau of Oudaudahroin in the Vatnajökull National Park. the height of the volcano is 1510 m above sea level. During the eruption of the volcano, which began on March 29, 1875, in the caldera of the volcano with an area of about 45 km? formed two large lakes. The last eruption is dated 1961.

Hekla is a stratovolcano located in southern Iceland. Height 1488 meters. It has erupted more than 20 times since 874 and is considered the most active volcano in Iceland. In the Middle Ages, the Icelanders called it the "Gate to Hell". Studies of volcanic ash deposits have shown that the volcano has been active for at least the past 6,600 years. The last eruption occurred on February 28, 2000.

Mount Ingolfsfjall is of volcanic origin, arose during the ice age and consists of basalt (at the base - mainly of palagonite). The height of the mountain is 551 meters, the top of the mountain is flat. The southern slopes of Ingolfsfjala, covered with silvery rock formations, are under state protection.

Curling is a volcano in the northern part of Iceland, on the Trøllaskagi peninsula, south of the Joksnadalheidi plateau. The volcano was active 6-7 million years ago. At the top of Curling there is a significant amount of liparitic rock and volcanic ash with a high content of silicate. The mountain itself consists mainly of basalt - like most of the Trøllaskagi mountains.

Lucky is a shield volcano in the south of Iceland, near the Eldgja Canyon and the town of Kirkjubayarklaustur in the Skaftafell National Park. In 934, a very large eruption occurred in the Laki system, about 19.6 km? lava. In 1783-1784, a powerful fissure eruption occurred on Lucky and the neighboring Grimsvotn volcano with an exit of about 15 km? basalt lava for 8 months. The length of the lava flow that erupted from a 25-kilometer fissure exceeded 130 km, and the area filled by it was 565 km².

Sulur is a volcano in the northern part of Iceland, in the Nordurland Eistra region. It is part of the system of the extinct volcano Kerling, located in the neighborhood. Sulur has two peaks, the higher one reaches 1213 meters, the smaller one - 1144 meters. The mountain is located southwest of the largest city in Northern Iceland - Akureyri.

Hengidl is a volcanic system that includes 2 volcanoes, one of which is Hengidl itself, and the other is the Hromandutindur volcano. The area of the volcanic system is about 100 km². The volcanic region extends from the Selvotur to the Laundökull glacier, and lies southwest of Lake Thingvadlavatn. Hegidl is one of the highest mountains in the region of the capital of Iceland - Reykjavik, its height is 803 meters. The last eruption of Hengidl occurred over 2,000 years ago.

Hofsjökull is the third largest glacier in Iceland (after Vatnajökull and Laundökull), as well as the largest active volcano on the island. The volcano is located at the junction of the Icelandic rift zones, has a caldera about 7 x 11 km in size under the western part of the glacier, and there are a number of other volcanic outcrops. The fumarole activity concentrated in the middle part of the complex is the strongest on the island.

Eldfell is located on the island of Heimaey in the Vestmannaeyjar archipelago. It was formed on January 23, 1973 as a result of an eruption on the outskirts of the city of Heimaey. The eruption of Eldfetl was a complete surprise for both scientists and local residents. Emissions from the volcano continued until July 1974, after which Eldfell lost activity. New eruptions, according to experts, are unlikely. The height of Eldfell is about 200 meters.

Eraivajokull is an ice-covered volcano in the southeastern part of Iceland. It is the largest active volcano on the island, on its northwestern edge is the highest point in the country - the Hvannadalshnukur peak. Geographically, it belongs to the Vatnajokul glacier, which is located within the Skaftafel National Park.

Thus, the study and monitoring of volcanoes is much more important than the mythical problem of warming, scientists say. Human impact on climate is likely to be greatly exaggerated. Meanwhile, tectonic processes can pose a real threat. Therefore, it is necessary to systematically monitor seismically hazardous zones, using not only seismic, but also neutron sensors. In Russia, potentially dangerous areas include the Caucasus with the dormant volcano Elbrus, Baikal, where a new fault is emerging in the earth's crust, and Kamchatka, whose volcanoes are the highest mountains in the world. The height of the Kamchatka volcanoes, if measured not from sea level, but from the bottom of the Kuril-Kamchatka trench, is about 12 thousand meters, far exceeding the height of the Himalayas. At the same time, Kamchatka volcanoes are not inferior to Icelandic ones in terms of their impact on the planet's climate.

Conclusion

According to the results of our study, the following data were obtained.

The largest historical events are associated with two volcanic eruptions that occurred in the 17th century. Then the volcanoes Hekla in Iceland and Etna in Sicily woke up. They threw a huge amount of ash and other particles up to 20 km into the stratosphere. The fact is that ash and dust settle very quickly in the atmosphere due to circulation - a week has passed since the Icelandic eruption, and the dust in the atmosphere has already dissipated. In the stratosphere, it rushes around the entire globe for a very long time and can cause a significant cooling. Such a cold snap occurred after the eruptions in the 17th century, and it caused very severe crop failures. As a result, there was a massive loss of livestock, which, in turn, caused famine and disease in people, massive epidemics of plague, cholera, and scarlet fever broke out, which wiped out half the population of Europe. Two volcanoes were an indirect cause of death of a huge number of people. This is one of the largest disasters that are described, including in literary works. The Church interpreted them as the Lord's punishment for human sins, etc. This is one of those examples that show how great the impact of volcanism on the climate and the fate of mankind.

The eruption of an Icelandic volcano is one of the clearest examples of the influence of volcanic processes and, in general, endogenous processes (such as tsunamis, earthquakes, floods) on human life, in particular, on information systems, air transportation systems and their relationship with climate. We are accustomed, when discussing these problems, to single out the anthropogenic component: the human impact on warming, on natural and man-made disasters, for example, this notorious greenhouse gas effect, primarily CO 2 . In fact, volcanism is one of the main machines that determines the climate and many other events. This is not the only eruption, they occur annually, having a noticeable impact on the life of specific regions. The uniqueness of this eruption lies in the fact that the ash cloud spread far and high above densely populated areas, and therefore caused, one might say, the collapse of air travel and a number of other consequences.

We have active volcanoes in Russia in Kamchatka and the Kuril Islands. The largest volcano - Klyuchevskaya Sopka - regularly ejects into the upper atmosphere and, more importantly, into the stratosphere - to a height of more than 10 kilometers - a huge amount of ash and gas, which more than once led to difficulties in air traffic in Alaska, Canada, and partly Japan. It didn't concern everyone else, so it didn't cause such a resonance. Aircraft accidents that happened in Indonesia were mentioned in the press, in the Philippines - this is the second densely populated area, which is very much affected by volcanic eruptions. From two sides, Southeast Asia is surrounded by very active volcanic arcs - the Philippine and Sumatra-Javanese, where, in addition to ash and CO 2, a lot of sulfur is also emitted, which, oxidized in the atmosphere, turns rain into acid. This dilute sulfuric acid has repeatedly caused irreparable damage to the crop. And when they write about acid rain associated with industrial activity, these are all trifles compared to volcanic causes.

Man is not capable of somehow influencing volcanic activity, but we can refine and improve our forecasts. Very few people in Russia are engaged in such forecasts - Kamchatka is far away, and what happens there is insignificant for our capitals. And in fact, these eruptions can have a global impact. I repeat, if the ashes are thrown into the stratosphere, this may already lead to larger consequences for the climate. Therefore, it is necessary to deal with the forecast of volcanism

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MOSCOW, 24 Oct - RIA Novosti. Volcanic eruptions not only cool the planet by throwing huge amounts of aerosols into the air, but also cause glaciers to melt faster due to the huge masses of ash thrown out during these same cataclysms, according to an article published in the journal Nature Communications.

“We all know that dark snow and ice melt faster than their white counterparts, this is all a very simple and obvious thing even for a child. But, on the other hand, no one has been able to show before that outbreaks of volcanism and episodes of rapid ice melting in were connected in the past,” said Francesco Muschitiello of Columbia University (USA).

Scientists: volcanoes orchestrated the climate in the last 2.5 thousand yearsClimatologists analyzed climate fluctuations during the existence of human civilization and came to the conclusion that in the last 2.5 thousand years, volcanic eruptions were the main reason for the growth and sharp drops in temperatures.

Volcanoes of the Earth today are considered one of the key "conductors" of the climate of our planet. They can either raise the temperature on its surface, throwing out huge masses of carbon dioxide and other greenhouse gases, or lower it, filling the Earth's atmosphere with ash particles and aerosol microdroplets that reflect the rays and heat of the Sun.

Mankind has already experienced several such catastrophes in the entire short history of its existence. For example, the eruption of the Toba supervolcano, which occurred about 70 thousand years ago, led to the onset of a "volcanic winter" for several years and the almost complete disappearance of people. Its smaller counterparts, the explosion of Tambor Island in 1815 and the massive volcanic eruption in South America in 530 AD, caused widespread famine and outbreaks of plague.

Muschitello and his colleagues found that volcanoes do not always unequivocally affect the climate, causing both ice melt and "volcanic winter" at the same time by studying silt deposits that formed at the bottom of a dried-up Baltic glacial lake. It was a large temporary reservoir that covered a significant part of modern Scandinavia during the Ice Age in the summer, when melt water from the glaciers began to flow into the basin of the future Baltic Sea.

Climate volcano: is it possible to “cancel” warming in one dayHas anyone blamed Krakatau for "global cooling"? And how much do volcanoes affect the Earth's climate? Andrey Kiselev, a senior researcher at the Voeikov Main Geophysical Observatory, told RIA Novosti about this.

This lake, according to current estimates of geologists, arose about 12 thousand years ago, at the end of the ice age. and it existed for several thousand years, accumulating at its bottom volcanic ash, pollen and other pieces of organic matter that can tell a lot about the climate of the era during which they arose.

Climatologists in this case were not interested in the contents, but in the appearance of its bottom sediments. Their thickness, as the researchers explain, is a kind of analogue of the growth rings of trees - the wider each layer of silt, the more water should have flowed into the lake from the slopes of retreating glaciers.

This feature of the bottom of the Baltic Lake helped scientists understand what role volcanoes played in its formation and filling, comparing changes in the thickness of the layers of silt with what “volcanic” substances were found inside ice deposits that formed in Greenland in the same era.

This comparison, contrary to the expectations of scientists, showed a rather strange picture. During volcanic eruptions that emitted large amounts of aerosols into the atmosphere, the rate of glacial melting did not fall, but grew or remained the same, despite the fact that such emissions lowered the average temperature by 3.5 degrees Celsius throughout Scandinavia.

Scientists: the onset of glaciation brought down Byzantium and created the CaliphateA series of three volcanic eruptions in the 6th century AD and the associated era of glaciation caused the decline of Byzantium at the end of the first millennium and contributed to the creation of the first Caliphate of the Arabs and their conquest of almost all the former possessions of the Romans.

The reason for this anomalous behavior of glaciers, according to the authors of the article, was volcanic ash - even small amounts of it, according to climatologists, could reduce the reflectivity of ice by 15-20%, which would significantly increase the heating of glaciers by the light and heat of the Sun and accelerate their melting.

One of these eruptions, as scientists suggest, could dramatically accelerate the rate of water accumulation in the Baltic Lake, which led to the formation of a channel between the oceans and this reservoir and the birth of the Baltic Sea.

All this, according to Muschitello, indicates that volcanoes may have played a much larger role in the end of the ice age than scientists now believe, and that their emissions affect the climate is not as clear-cut as previously thought.

Volcanoes erupt in different ways. Rivers of liquid basaltic lava flow from some, others spew clouds of hot volcanic ash and pumice fragments, still others shoot volcanic bombs - frozen pieces of lava and tephra (petrified ash), fourth ones explode so that pieces of rock scatter for tens of kilometers. And there are those who do it all at once, they are the most dangerous.

Winter is... a thousand years long
Scientists have long studied the volcanic activity of the earth's crust. They even came up with a criterion by which one can classify the strength of volcanic eruptions - the scale of volcanic eruptions (Volcanic Explosivity Index - VEI). It is known, for example, that a powerful eruption occurred about 600 thousand years ago. The Yellowstone supervolcano on the west coast of North America has thrown more than 2.5 thousand cubic kilometers of ash into the atmosphere. After the eruption, a crater-caldera measuring 55 by 72 kilometers remained. It is possible that this eruption so affected the DNA of pithecanthropes that a mutation arose - Neanderthals, who became the ancestors of man. And about 70 thousand years ago, the most destructive of the eruptions known to science today happened - the Toba volcano on the island of Sumatra “spoke”. As a result of the cataclysm, a monstrous release of sulfur into the atmosphere occurred, poisonous clouds enveloped the planet, and real winter reigned on Earth for a thousand years. For the first decade there were poisonous sulfurous rains that killed all life. Clouds covered the Earth from the Sun, and the climate on the planet became colder. Not many representatives of flora and fauna survived this catastrophe, and the number of our ancestors was reduced to only a few thousand people.

Most recently (by the standards of scientists) - only about 27 thousand years ago - there was a major eruption of the Taupo (Oruanui) volcano in New Zealand. More than a thousand cubic kilometers of ash and tephra were ejected from its mouth into the atmosphere, and the mouth itself expanded so much that later a huge lake 44 kilometers long and almost 200 meters deep was formed at this place. According to the scale of volcanic eruptions (VEI), this natural event was assigned the highest rating - 8 points. North Island, which occupies half of the territory of New Zealand, was covered with a layer of tephra 200 meters thick. There is hardly anything alive here.

Sinister Krakatoa
Volcanoes continued to influence the planet's climate and spoil the lives of our ancestors. In the 6th century, the young Krakatoa volcano in Indonesia entered the scene of natural disturbances. Its mouth, consisting of many layers of hardened lava, is directed strictly upwards and is capable of throwing ash and tephra to great heights. Volcanic eruption in 535 AD the atmosphere was so polluted that global climate changes occurred, a giant rift formed in the earth's crust, and two new islands appeared - Sumatra and Java.
However, Krakatau did not rest on this and in 1883 woke up again, spewing a column of ash to a height of thirty kilometers and destroying the island on which he himself was located. Ocean water rushed into a hot earth cleft, resulting in a monstrous explosion in its power. The rising thirty-meter wave washed away about three hundred cities and villages from the islands into the ocean, killing 35 thousand people. The red-hot contents of the volcano scattered within a radius of 500 kilometers. The force of the eruption, equal to six points on the VEI scale, was thousands of times greater than the force of the explosion of the atomic bomb dropped on Hiroshima. The air wave circled the planet several times. In Jakarta, the capital of Indonesia, 150 kilometers away, she tore roofs off houses and doors off their hinges.
Clouds of dust and ash swirled over the ocean for several years. Three small islands remain from Krakatoa itself. It would seem that one could put an end to its history, but the volcano turned out to be surprisingly tenacious. Seismic activity in this region has not subsided. At the site of the eruption, new vents appeared, then were washed away by the ocean, which scientists called Anak-Krakatau (child of Krakatau). The first such "baby" appeared in 1933 and reached a height of 67 meters, the second - in 1960, and today the sixth "child" looks at its surroundings from a height of 813 meters. The "kid" feels great, and the government of the country begins to worry about the future of the population of the islands. It has already been decided - out of harm's way - to settle no closer than three kilometers from the "cradle".

catastrophic consequences
However, not only the southern countries can boast of volcanoes that have written the history of mankind. Iceland also contributed to the formation of the Earth's climate. And it's all thanks to Lucky. This so-called shield volcano, whose slopes are created by layers of hardened lava flows layered on top of each other, consists of more than a hundred craters. Their vents, reaching a height of 800 meters, stretched for 25 kilometers in the form of a ridge that crosses the Skaftafell National Park in the southern part of the island. In the center of the ridge is the volcano Grimsvotn. It was Lucky and Grimsvotn during the eruptions in 1783-1784 that poured out an incredible amount of lava for eight months, which formed a fiery river 130 kilometers long. The eruption was accompanied by emissions of poisonous gases, which killed half of the island's livestock. Ash covered pastures, and lava melted glaciers that flooded the island with water. As a result of the flood and the famine that followed, one in five inhabitants of Iceland died. Clouds of ash scattered across the Northern Hemisphere, causing a sharp cooling, which led to crop failure and famine in Europe.
Even more serious consequences were from the eruption of the Tambora volcano on the island of Sumbawa (Malay Archipelago) in 1815. The volcano is located in the so-called subduction zone, when the edge of the earth's crust layer is immersed in the boiling mantle. During the period of seismic activity, lava is scooped up by this edge, like a spoon, and is pushed to the surface of the earth under enormous pressure. If at least one natural passage exists at this place, lava rushes to the surface through it. The seven-point eruption of Tambora became one of the most destructive in the history of mankind. More than seventy thousand people died from it. The inhabitants of the island almost completely died out from the famine and disease that followed the eruption, taking the unique Tambor language with them to the grave. A volcanic winter set in on the planet, which led to a catastrophic crop failure in Europe in 1816, famine and mass emigration of the population to America.

Fire-breathing Kamchatka
Although Russia is not a southern country, we also have something to brag about. In the eastern part of the Kamchatka Peninsula is the famous Bezymyanny volcano. There are about a thousand of them in Kamchatka, and they are of different shapes and are in different stages of activity - from "sleeping" to active. For example, Klyuchevskaya Sopka with a height of 4750 meters is the highest active volcano in Eurasia. Even at the beginning of the last century, the height of Bezymyanny was 3075 meters. But as a result of the 1956 eruption, its top was shortened by almost two hundred meters. Oddly enough, but during the eruption, despite its terrifying power, people were not injured. At first, the volcano was shaken by convulsions for half a year, accompanied by minor ejections of ash and splashes of lava, and then on March 30 it simply exploded, throwing clouds of tephra heated to 300 degrees to a height of 35 kilometers. And huge flows of fiery lava poured out of a giant hole gaping on the eastern slope. Hot ash melted the snow - and along the riverbed, sweeping away everything in its path, mud flows rushed, in which huge boulders mixed with the trunks of uprooted trees. Clouds of ash covered the village of Klyuchi, located not far from Bezymyanny, and its residents, returning from work, were forced to search for their homes almost by touch. Spreading their arms and bumping into each other, they wandered from building to building, trying to see at least something in the pitch darkness. But the inhabitants of Great Britain could soon admire unusually beautiful sunsets caused by atmospheric pollution as a result of the emissions of the Nameless.