Dormant volcanoes: what danger they pose. The highest active and extinct volcanoes in the world

10 largest and most dangerous volcanoes on Earth.

A volcano is a geological formation that arose due to the movement of tectonic plates, their collision and the formation of faults. As a result of collisions of tectonic plates, faults are formed, and magma comes to the surface of the Earth. As a rule, volcanoes are a mountain, at the tip of which there is a crater, which is the place where the lava comes out.


Volcanoes are divided into:


- operating;
- sleeping;
- extinct;

Active volcanoes are those that have erupted in the short term (approximately 12,000 years)
Dormant volcanoes are called volcanoes that have not erupted in the near historical perspective, but their eruption is practically possible.
Extinct volcanoes include those that have not erupted in the near historical future, however, the top has the shape of a crater, but such volcanoes are unlikely to erupt.

List of the 10 most dangerous volcanoes in the world:

1. (Hawaii, USA)



Located in the islands of Hawaii, it is one of the five volcanoes that make up the islands of Hawaii. It is the largest volcano in the world in terms of volume. It contains over 32 cubic kilometers of magma.
The volcano formed about 700,000 years ago.
The last volcanic eruption occurred in March 1984, and it lasted more than 24 days, causing great damage to people and the surrounding area.

2. Taal Volcano (Philippines)




The volcano is located on the island of Luzon, belonging to the Philippine Islands. The crater of the volcano rises 350 meters above the surface of Lake Taal and is located almost in the center of the lake.

The peculiarity of this volcano is that it is located in the crater of a very old extinct mega volcano, now this crater is filled with lake water.
In 1911, the most powerful eruption of this volcano occurred - then 1335 people died, within 10 minutes all life around the volcano died at a distance of 10 km.
The last eruption of this volcano was observed in 1965, which led to 200 human casualties.

3. Merapi Volcano (Java Island)




The name of the volcano in the literal sense is the Mountain of Fire. The volcano has been systematically erupting over the past 10,000 years. The volcano is located near the city of Yogyakarta, Indonesia, the population of the city is several thousand people.
It was the most active volcano among the 130 volcanoes in Indonesia. It was believed that the eruption of this volcano led to the decline of the Hindu Kingdom of Matarama. The peculiarity and horror of this volcano is the speed of magma propagation, which is more than 150 km / h. The last volcanic eruption occurred in 2006 and claimed 130 lives and made more than 300,000 people homeless.

4. Santa Maria Volcano (Guatemala)


It is one of the most active volcanoes of the 20th century.
It is located at a distance of 130 kilometers from the city of Guatemala, and is located in the so-called Pacific. Ring of Fire. The Santa Maria crater was formed after it erupted in 1902. About 6,000 people died then. The last eruption occurred in March 2011.

5. Volcano Ulawun (Papua New Guinea)


Ulawun volcano, located in the region of New Guinea, began to erupt from the beginning of the 18th century. Since then, eruptions have been recorded 22 times.
In 1980, the largest volcanic eruption occurred. The ejected ash covered an area of ​​more than 20 square kilometers.
Now this volcano is the highest peak in the region.
The last volcanic eruption occurred in the year 2010.

6. Volcano Galeras (Colombia)




The Galeras volcano is located near the border of Ecuador in Colombia. One of the most active volcanoes in Colombia, it has been systematically erupting over the past 1000 years.
The first documented volcanic eruption occurred in 1580. This volcano is considered the most dangerous because of its sudden eruptions. Along the eastern slope of the volcano is the city of Paphos (Pasto). Paphos is a residence for 450,000 people.
In 1993, six seismologists and three tourists died during a volcanic eruption.
Since then, the volcano has erupted every year, claiming thousands of lives and making many people homeless. The last volcanic eruption occurred in January 2010.

7. Volcano Sakurajima (Japan)




Until 1914, this volcanic mountain was located on a separate island in the immediate vicinity of Kyushu. After a volcanic eruption in 1914, a lava flow connected the mountain to the Ozumi Peninsula (Japan). The volcano was named as Vesuvius of the East.
It serves as a threat to the 700,000 people of Kagoshima City.
Since the year 1955, eruptions have occurred every year.
The government even built a refugee camp for the people of Kagoshima so they could find shelter during the volcanic eruption.
The last volcanic eruption occurred on August 18, 2013.


8. Nyiragongo (DR Congo)




It is one of the most active, active volcanoes in the African region. The volcano is located in the Democratic Republic of the Congo. The volcano has been monitored since 1882. Since the beginning of observations, 34 eruptions have been recorded.
The crater in the mountain serves as a holder for the magma fluid. In 1977, there was a major eruption, neighboring villages were burned by hot lava flows. The average speed of the lava flow was 60 kilometers per hour. Hundreds of people died. The most recent eruption occurred in the year 2002, leaving 120,000 people homeless.




This volcano is a caldera - the formation of a pronounced rounded shape with a flat bottom.
The volcano is located in the Yellow National Park of the United States.
This volcano has not erupted for 640,000 years.
The question arises: How can it be an active volcano?
There are claims that 640,000 years ago, this super volcano erupted.
This eruption changed the terrain and covered half of the US in ash.
According to various estimates, the volcanic eruption cycle is 700,000 - 600,000 years. Scientists expect this volcano to erupt at any time.
This volcano could destroy life on Earth.

On the Armenian Highlands. It is located on the territory of Turkey, but for a long time belonged to Armenia and is a symbol of this state. The mountain consists of two peaks - Big and Small Ararat, the cones of which were formed after the volcanic eruption. The first has a height of 5165 meters, the second - 3925 meters above sea level. They are located at a fairly large distance from each other and look like two separate mountains. Both peaks are extinct, although activity in the depths of this area has clearly not stopped: in 1840, a small eruption occurred in the vicinity, which caused an earthquake and an avalanche.

Elbrus and Kazbek

The highest point in Europe - Elbrus - is also often called a stratovolcano, although this title can be disputed, as it happened in the historical period, in the 1st century AD. Although the scale of this eruption was insignificant compared to what this volcano did in prehistoric times. It was formed more than twenty million years ago, at the dawn of its existence it erupted many times, throwing out a huge amount of ash.

Kazbek is also called extinct, but its last earthquake occurred in 650 BC. Therefore, many scientists rank it among the active ones, because not much time has passed by geological standards.

Other extinct volcanoes

There are more truly extinct volcanoes, which have not shown their activity for more than ten thousand years, than active ones - several hundred, but they are almost unknown among the broad masses, since most of them, due to their antiquity, do not differ in height and large sizes. Many of them are located in Kamchatka: these are Klyuchevaya, Olka, Chavycha, Spokoiny, some of them are in the form of islands formed as a result of the eruption. Several volcanoes, presumably incapable of eruption, are located in the Baikal region: Kovrizhka, Podgorny, Talskaya peak.

One of the Scottish castles is built on the remains of a very ancient extinct volcano, which last erupted more than three hundred million years ago. Almost nothing remains of its slopes - during the ice age, glaciers broke them. In New Mexico, there is Ship Rock, also a remnant of an ancient volcano: its walls are almost completely destroyed, and a channel with solidified magma is partially exposed.

For a long time, the Mexican volcano El Chichon was considered extinct, but in 1982 it suddenly began to erupt. Scientists began to study it and found out that the previous eruption occurred not so long ago - a little over a thousand years ago, they simply did not know anything about it.

An ordinary person does not see much difference between "extinct" and "sleeping" volcanoes. In fact, the differences are very significant, because a conditionally “sleeping” volcanic formation can suddenly wake up, and then it will not seem enough to anyone.

Another thing is that they are completely safe, which is actively used by travel companies and outdoor enthusiasts. What are the main features of extinct volcanoes?

The Physics of a Volcano Eruption - How It Becomes Extinct

The eruption occurs due to the presence in the magma not only of water vapor, but also of various gases: hydrogen chloride and fluoride, sulfur oxides and, methane, nitrogen, carbon dioxide, etc.

In a "sleeping" volcano, the concentration of gases dissolved in magma corresponds to the level of pressure under which the magma is at a certain depth. Thus, a state of equilibrium is maintained.

However, due to earthquakes that shift parts of the crust, a decrease in pressure may occur, for example, in the area of ​​a magma chamber. The state of equilibrium is disturbed and the gases immediately increase in volume due to the transition to the gaseous state.

The foaming magma begins to move upward, which leads to an even greater drop in pressure, and hence to an acceleration of the process of outgassing from the magma.

Accordingly, the probability of his awakening tends to zero.

List of famous extinct volcanoes in the world

Volcanoes that do not pose any threat are located on all seven continents: in North and South America, Asia, Africa, Europe, Antarctica and Australia.

To date, there are over two hundred extinct volcanoes in the world. The most characteristic representatives of this type are presented below.

Rocky

This extinct volcano is located on the Kamchatka Peninsula, in the very center of the Sredinny Range. The highest point of the volcano is at around 1759 meters above sea level.

According to geologists, the last time Kamenisty was active was about two and a half million years ago. The volcano was formed by lava flows and pyroclastic rocks. The volcanic form in the form of a gentle cone does not end with a crater destroyed by erosion, but with a steep peak.

Arayat

It is located in Luzon, the largest island in the Philippines. The highest point is 1025 meters.

The last eruption occurred, most likely, about 10 thousand years ago. Despite the erosion that hit the northern and western parts of the crater, it still remained on top.

Damavand

It is located in the Iranian province of Mazendiran and is the highest point of the Elburs mountain system (5620 meters above sea level). The last eruption was recorded around 5350 BC.

Damavend has the shape of a gentle cone and rises above Elburz for one and a half kilometers. The volcanic cone was formed by andesitic lava, but there are also glaciers on the slopes.

Sajama (Sajama)

Located in Bolivia, in the Central Andes. The highest point above sea level is 6542 meters. Sajama is part of the National Park of the same name, located near the Chilean border.

The exact date of the last activity is not known for certain, but many scientists insist on the epoch of the Quaternary Holocene, i.e. about 12 thousand years ago.

Sajama is a classic cone-shaped stratovolcano, composed of hardened lava and its debris. At an altitude of more than 6000 meters, it is covered with never-melting snow and ice.

Aconcagua

It is considered the highest extinct volcano located all in the same Andes, but already on Argentinean territory. The peak is located at around 6961 meters above sea level.

Aconcagua, he is considered not only the champion among his fellows, but also the highest point of the southern and western hemispheres. For these merits, he even got into the list of the highest peaks of the six parts of the world "Seven Summits".

Aconcagua is also one of the oldest volcanic formations on the planet.

The exact date is unknown, but many scientists conclude that it arose about 150 million years ago.

Excursions to extinct volcanoes

The traditional excursion lasts 1-2 days and involves either climbing to the peaks by helicopters or hiking.

Some volcanoes are even equipped with special areas where tourists can stop and enjoy the natural views from high altitudes.

Extinct volcanoes are not only a living reminder of the great power of nature.

Thanks to their large number anywhere in the world, anyone can organize an appropriate hiking trip and get an unforgettable experience.

In the first decades of the XIX century. extinct volcanoes interested many geologists more than modern fire-breathing mountains; Auvergne, the Eiffel and Northern Ireland have been the subject of heated debate more often than Vesuvius or Etna. First of all, a dispute about basalts flared up. A. Werner (1750-1817), a world-famous scientist, the first professor of geology at the Freiberg Mining Academy in Saxony, came up with an erroneous concept about the sedimentary, that is, water, origin of basalts. The ideas of the "Neptunists" were also shared by Goethe. However, the students of A. Werner - A. Humboldt and L. von Buch correctly understood the volcanic nature of basalts, which contributed to the victory of the "plutonists".

a. VOLCANIC CHAIN ​​OF PUY (AUVERGNE)
Probably nowhere in Europe are extinct volcanoes so well preserved as in Auvergne, near Clermont-Ferrand, central France (Fig. 27.1). In some places they form a chain - hence the name "Puy chain" (by "Puy" is meant a hill clearly expressed in the relief). Already from the window of the train going from Paris to Clermont-Ferrand, one can observe both the chain-like arrangement of volcanoes and the sharp border between the mountains and the plain (that is, between the Central Massif and the Liman graben), passing along the normal ledge. The widely known mineral springs of France - Vichy are confined to the eastern side of the graben. Almost all volcanoes are located on a plateau, composed in places of very ancient (Precambrian) gneisses, in places of relatively ancient (Carboniferous) granites (Fig. 27.2).

The Puy de Dome, rising 1465 m behind Clermont-Ferrand, is the highest of the young volcanoes (Fig. 27.3). By car, it is easy to climb it, and the trip will be justified, since the distant surroundings are well viewed from the wide top. Now this peak is used for television purposes, and once upon a time there was a Roman temple of Mercury built from domite (domite is a rock named after the Puy de Dome volcano)! However, for the construction of this temple, they did not use local domite (it is too fragile), but domite, which was delivered with great difficulty from Mount Sarkui and from other places. The French geologist F. Glanzho in one of his works on the “Puy chain” (1913) recalls that one of the first built aircraft landed here. In 1908, the Michel brothers (famous rubber tire manufacturers from Clermont-Ferrand) established a prize of 100,000 francs for anyone who could fly from Paris to the top of the Puy-de-Dome in 6 hours. Eugene Renault succeeded on March 7, 1911. The possibility of landing is geologically substantiated: Puy de Dome is an extrusive (consisting of viscous lava - trachyte) squeezed out of a crater) very flat dome.

The famous French philosopher, mathematician and physicist B. Pascal, who was born in Clermont-Ferrand in 1623, made his famous experiment on weighing air in 1648 on Mount Puy-de-Dome. Then it was already known that air pressure is equal to the pressure of a column of mercury 76 cm high, then Torricelli explained by the "weight" of air; but his suggestion was not accepted. Pascal had the idea to test this on a mountain, where the weight of the air should be less. His relative Perrier successfully carried out this significant experiment: the barometer needle on the Puy-de-Dome volcano showed that the pressure here was 8 cm lower than in Clermont-Ferrand.
The first geologist to explore this area was Jean Guettard (born in 1715), the son of an apothecary, curator of the collections of the Duke of Orleans, later a member of the Paris Academy (died in 1786 in Paris). He compiled a mineralogical map of France and England; he is the author of the first major study on mountain erosion. In 1751, during a trip to the Auvergne, he established that the material used in the construction of houses and for paving roads (Volvik stone) was volcanic lava. This "trace" led him to the discovery of the extinct volcanoes of Auvergne. Gettar investigated 16 volcanoes, however, having found basalts with columnar separation on Mont-Dore, he attributed them to sedimentary origin. His work on the Auvergne was published in 1756.
It was in the Auvergne that the dispute between Neptunists and Plutonists began. With regard to basalts (but not in relation to cinder cones!) Gettar supported the former, and Desmarets (1765) supported the latter.
Among the first explorers of the Auvergne, one should also mention Giraud-Soulavi, an original self-taught supporter of the ideas of the Plutonists, who even tried (in the 18th century!) to establish the sequence of volcanic events. Abbot at Nimes, then vicar at Chalons, an ardent revolutionary and Jacobin, he died in 1813 in Geneva. In his seven-volume work Natural History of Southern France, he tried to "link" the data of his geological research with the Bible and the teachings of the Catholic Church. Let's not judge whether he succeeded.
Sulavi developed the notion that the character of a person depends on the soil and the geographical location of the area. The air of volcanic regions is allegedly constantly saturated with "electric matter", therefore the nerves of a person are constantly excited and stretched; on the contrary, in areas composed of limestone, shale, granite and pebbles, due to a lack of electricity, the physical and spiritual forces of a person are weakened.
Considering this early period of research at Auvergne, mention should also be made of Humphrey Davy, a major English chemist, whose name is associated with the invention of the safety miner's lamp (Davy's lamp). In 1812, with a letter of recommendation from Napoleon in his pocket, he arrived in Pariou to prove the validity of his theory, according to which volcanic eruptions occur due to the action of water on alkali metals.
The centers of the Auvergne volcanic eruptions are perfectly preserved in places. Among them, two sharply distinct groups can be distinguished. The first, smaller, includes light trachyte domes without cinder and tuff cones and without craters (for example, Puy de Dome). Very viscous lava rises up the vent of the volcano in the form of a cork; French geologists cite Pele Peak on the island of Martinique as an example of such a “plug”. There are no lava flows in this group of volcanoes (Fig. 27.4).

Some trachytes are called domites - this is how L. von Buch in 1809 called the biotite and plagioclase trachytes of the Puy-de-Dome volcano. However, they are also observed on other "puy", for example, on Mount Sarkui.
The second, more numerous group is formed by crater volcanoes, small cones composed almost exclusively of andesitic and dark basalt layered loose strata (Fig. 27.5). But here, too, the first erupted lavas were often trachytes.

These volcanic centers are characterized by lava flows, the original chaotic landscape of which is still discernible in some places, despite the vegetation covering them. The local name for streams is "cheires". They flowed into the Liman graben and into the valleys (which, therefore, already existed then), often completely filling them, which caused the rivers to dam. Lava flows reached a length of 10-20 km; where they overlapped one another, their total thickness reaches 100 m (Fig. 27.6).

Lava has long been used as a building material. Above, we have already talked about the famous and valuable "Wolvik stone", which belongs to the group of trachytes containing andesine. The ground water filtered through the lava becomes so pure that it is taken out in cans to other parts of the country.
The most beautiful crater volcano, in my opinion, is the andesitic Puy de Pariou, 1210 m high (Fig. 27.5). In structure (two shafts nested one in the other), it resembles, of course, the incomparably larger Vesuvius. In its picturesque crater on August 30, 1833, on the initiative of Lecoq, the founding of the French Geological Society was celebrated: “The ceiling of the meeting room was the blue sky, the lamp was the sun; the carpets were green grass and flowers, hiding the hearth of a former eruption. Never before have craters and geologists been so friendly."
Eruptions undoubtedly took place in the Quaternary, even during the last glaciation and later. The youngest lava covers are buried under the pebbles of the terraces, in which the bones of the reindeer were found - therefore, their age is not older than the wurm. According to absolute radiocarbon age determinations, Pariou erupted 7,700 years ago and Puy de la Vache erupted 8,800 years ago.
The Quaternary age of the eruptions is also confirmed by the excellent preservation of the volcanic cones, apparently younger than the Eifel cones.

b) MAAR EIFEL
Maars are small rounded, often relatively deep, cauldron-shaped depressions that pleasantly break the monotony of the landscape of the Rhine Slate Mountains. Geologically, they are so distinctive that the Rhenish name "maars" for these partially water-filled craters has become international. The word "maars" comes from the Latin mare (sea). The teacher of the Trier gymnasium I. Steininger (1794-1878), to whom we owe detailed information about the "extinct volcanoes of the Eifel and the Lower Rhine", was the first to use this Eifelian name to refer to this kind of volcanic forms.
However, the first geological observations in the "volcanic Eifel" were carried out much earlier, under the sign of a dispute (as in Auvergne) between plutonists and Neptunists. C. Nose (the mineral noseane is named after him) in Orographic Notes on the Siebengebirge and the Adjoining Partly Volcanic Regions of the Lower Rhine (1790) considered the Rhineland as at least partly "volcanic". However, he did not consider the maar-like Lake Laakh (now no longer attributed to the maars proper) to be volcanic.
In 1790 these places were visited by G. Forster, J. Cook's companion in his second round-the-world voyage, and later an active participant in the French Revolution. He considered the comparison of the Rhineland with Hekla and Etna "an amusing fantasy". Volcanological research in the Eifel was carried out by the mining director from Bonn E. Dechen (1800-1889), later the director of the Geological Office of North Rhine-Westphalia, W. Arene and the Bonn petrographer I. Frechen. A summary work on the maars has recently been done by G. Knoll.

Particularly picturesque maars are located in the western Eifel (Fig. 27.7): the deepest maar Pulfer (74 m; Fig. 27.8-27.9), the Weinfeld, Schalkenmehren and Gemünde maars lying close to each other, as well as the largest Meerfeld maar with a diameter of 1480 m. Some data on these maars are given in the table.

Some of these maars silted up and turned into swamps (Fig. 27.10). A particularly picturesque view opens from the plane. In 20 minutes you will see at least a dozen maars and see that these are crater-like funnels; however, unlike ordinary craters, they have never crowned a high volcanic mountain and are a depression in non-volcanic rocks (for example, in the Eifel - in ancient Devonian shales, greywackes, etc.). These are "negative volcanic forms" as opposed to "positive" forms such as Vesuvius, in other words, they are small but quite independent volcanoes, consisting only of a crater. True, in the formation of some maars, for example, the Meerfeld maar, subsidence processes took part (and not only volcanic eruptions, as in the craters proper).

Eifelian maars never erupted lava flows, but they erupted fine-grained basalt tuffs, often mixed with fragments of non-volcanic Devonian rocks; one of the maars - Dreiser-Weier (now dried up) threw out large green olivine concretions, which are of interest to mineralogists. True, the volume of eruption products is significantly inferior to the volume of crater funnels (for example, in Meerfeld maar). Since the time of Steininger, the formation of maars has been explained primarily by the explosive release of volcanic gases. “These are like mine explosion craters,” A. Humboldt wrote in his Cosmos. Indeed, the ratio of diameter to depth is the same for maars and craters formed during artificial explosions (as well as for similar forms on the Moon). It was believed that explosive volcanic gases first rushed up the cracks, thus creating "volcanic channels" (also called vents, necks and diatremes), which expand near the surface - in the form of explosion funnels.
However, it is currently assumed that the formation of maars is associated not with a single explosive breakthrough of gases, but with the gradual expulsion of volcanic gases from the depths along weakened zones of the earth's crust. At the same time, gases mechanically expand the channels through which they go outside; particles torn off by gases, as well as larger fragments of wall rocks, mix with erupting gas and trapped lava droplets. “Consequently, volcanic channels are not opened by suddenly erupting gases ... magmatic gases, by mechanical expansion of cracks, create their way up” (G. Knoll, 1967). In the Eifelian and other similar volcanoes, processes similar to some methods used in the chemical industry took place - fluidization, or fluidization. The gas and the fine particles of matter swirled by it form a mixture that behaves like a liquid.
Based on his theory, Noll proposed a new definition of maar.
“Maars are independent funnel-shaped or saucer-shaped volcanoes, which are depressions in any rocks. They are formed as a result of the eruption of gas or water vapor, usually with the participation of fluidization processes, mainly during one eruptive cycle. As a rule, they are surrounded by a cover of loose rocks or a low mound of ejecta and may have a small central cone.
Eiffel maars have no central cones. However, they are observed, for example, in South Australian maars. There, volcanic activity apparently continued somewhat longer than in the Eifel, where its duration probably did not exceed a few weeks or months.
The fact that the maars are partially silted undermines their landscape value, but at the same time increases their scientific value: pollen-containing peat deposits of maars allow more accurate age determinations using pollen analysis and radiocarbon dating. So, G. Strak and I. Frechen managed to establish the age of maar eruptions (see table). At the same time, thin interlayers of volcanic ash in the layers of peatlands or between them acquire great importance (Fig. 27.11).

Thus, these maars, as well as the Laach volcano (11 thousand years old) with its pumice tuffs scattered up to Mecklenburg and Lake Constance, are the youngest volcanoes in the territory of Germany. Of course, this method of age determination proceeds from the fact that peat formation began shortly after the appearance of the maars and that the ash layers are associated with this volcano and not with another. In this regard, recently (1968) doubts were expressed by P. Jungerius and others, who suggest that the ashes come in part from the Laach volcano. Then all the above numbers characterize the minimum age of individual maars: eruptions were not necessarily, but could be older, although hardly much older.
Similar but much older and more heavily eroded volcanic edifices in the Swabian Alb near Urach were formerly called "volcanic embryos". But maars are by no means the initial, but rather the final stage of volcanic activity. Deep magma was no longer capable of creating large volcanoes.

c) BRIDGE OF GIANTS (NORTHERN IRELAND)
The best-known locality of columnar basalts is the Giants Causeway. Along the coast for almost 100 m at Antrim in Northern Ireland, thousands or tens of thousands of these pillars form a regular mosaic in places. This is not exactly a “road”, but rather a basalt pavement, partially flooded by the sea at high tide. Of the 100 pillars, about 70 are hexagonal, and this is not accidental, since it takes less work to divide a surface into hexagons than to divide it into squares or triangles. The thickness of the pillars ranges from 15 cm to half a meter. Most of them stand upright (Fig. 27.12).

It is now quite clear to us that such a beautiful columnar separation arose during the solidification of lava and its reduction in volume. However, in the time of Goethe, the regular mosaic was compared with crystals formed in aqueous solutions, seeing this as evidence of the aqueous origin of basalts.
In addition, other observations were made in Antrim, which at first seemed to confirm the ideas of the "Neptunists". Near Portrush, marine shales and marls of the Jurassic (Liassic) age with abundant ammonite fauna occur on the basalts. Hot basaltic lava, which intruded into the Liassian deposits in the form of veins, turned the shales into dark siliceous rock at the contacts, which the first researchers also mistook for basalt. Well, since sea shells are found in this "basalt", how can one doubt its aquatic origin. And only later did they learn to distinguish basalts from basalt-like, altered by "contact metamorphism" sedimentary deposits of the Lias.

A little to the west of Mostovaya Giants, one can see that black basalt lavas lie on snow-white chalk layers (Fig. 27.13). These strata with lenses of chert concretions are Late Cretaceous marine deposits, as evidenced by numerous finds of belemnites. The sea surf has developed picturesque bays, caves, arches in these deposits (Fig. 27.14).

The lava flows that now form the Bridge of the Giants are undoubtedly younger than the Cretaceous, since they overlap the Cretaceous deposits (Fig. 27.15). The basalts belong to the Tertiary period (probably to the Miocene), and their age, therefore, is several tens of millions of years. This is directly confirmed by the finds of fossil flora in clay interbeds enclosed between individual lava covers. Clay interlayers are red in color - a consequence of a fairly warm subtropical climate in the Tertiary. A series of red-colored rocks with a thickness of several meters stands out sharply in a steep coastal cliff for many kilometers. This sequence indicates that the "lower" basalts were weathered into laterite, which developed lush vegetation (sequoia, pine, etc.) before, after a long break, everything was buried under the younger ("middle") basalts. The basalts of the Bridge of the Giants are much older than the "puy" of the Auvergne and the maars of the Eiffel, which are very young from a geological point of view. It is therefore not surprising that the Antrim basalt pillars are the last remnants of an undoubtedly larger volcanic region; most of it has long been demolished, and the volcanic centers have survived only in places. Basalts, very reminiscent of Northern Ireland, are also known in the Faroe Islands, in the east and north-west of Iceland, in Greenland. It is highly doubtful that these basalts once formed a single giant basalt plateau, and yet they are united under the general name of the "Thule Basalt Province".

Volcanoes- geological formations on the surface of the earth's crust, through which magma appears. The name comes from the Roman god of fire - Vulcan. Today there are more than 1000 active volcanoes on the planet. Next, we will introduce you to the classification of volcanoes, tell you where most of them are located and which are considered the highest and most famous.

Volcanoes: interesting facts

There is a large classification of volcanoes. So everything volcanoes of the world are divided into 3 types:
By appearance (thyroid, stratovolcanoes, cinder cones, domes);
By location (podlenikovye, terrestrial, underwater);
By activity (extinct, dormant, active).

Each volcano consists of the following parts:
Main crater;
Side crater;
Vent.


Some volcanoes do not erupt lava. There are also mud volcanoes, and geysers are also post-volcanic formations.

Where are the volcanoes of the world

Most of the volcanoes are located in the Andes, Indonesia, Iceland, Hawaii and Kamchatka. However, they are not located randomly, but in strictly defined zones:
Most of the volcanoes are located in a zone called the Pacific Ring of Fire: in the Andes, Cordillera, Kamchatka, as well as in the Philippines and New Zealand. Nearly all are located here. active volcanoes terrestrial world - 328 out of 540.
Another location zone is the Mediterranean fold belt, which includes the Mediterranean Sea (Santorini, Etna, Vesuvius) and stretches to Indonesia, where almost all the powerful eruptions of the world took place: Tambora in 1815 and Krakatoa in 1883.
Mid-Atlantic Ridge, forming entire volcanic islands. Vivid examples: Canary Islands, Iceland.

Active volcanoes of the world

Most of the active volcanoes are located in the above zones. Volcanoes often erupt in Iceland, periodically reminds of itself the highest volcano in Europe - Etna. Others that are particularly well known are:
Popocatepetl, located near Mexico City;
Vesuvius;
Mauna Loa;
Nyiragongo (DR Congo), famous for its huge lake of boiling lava, located in the crater.

Extinct volcanoes of the world

Volcanoes often complete active eruptions. Some of them are considered extinct, others are considered dormant. Extinct volcanoes of the world located throughout the planet, including in the Andes, where the highest volcano in the world is located - (6893 meters), as well as the mountain of volcanic origin Aconcagua (the main peak of South America).

Often extinct volcanoes used as observatories, for example, Mauna Kea in the Hawaiian Islands, in the crater of which 13 telescopes are installed. By the way, it is Mauna Kea that is recognized as the highest volcano in general, if we consider the underwater part, then its height is 10,205 meters.

The most famous volcanoes in the world

Everyone heard stories about terrible eruptions that destroyed entire cities and destroyed islands. Here we will talk about:
Vesuvius, this small volcano in Italy (1281 m) destroyed the city of Pompeii. This moment is even captured in Bryullov's painting The Last Day of Pompeii.
Etna is the highest volcano in Europe that erupts periodically. The last eruption took place in May 2015.
Krakatau is a volcano in Indonesia that erupted in 1883 with the explosion of 10,000 atomic bombs. Now in its place rises a new volcano - Anak-Krakatau.
Tambor. In 1815, the most powerful eruption of our time took place, as a result of which a volcanic winter came (the pollution of the atmosphere with ash), and 1816 became a year without a summer.
Santorini, which destroyed the Minoan civilization and destroyed an entire island in the Mediterranean Sea.
Mont Pele on Martinique, which destroyed the port of Saint-Pierre in a matter of minutes. 36,000 people died
The Yellowstone Caldera is a potential supervolcano whose eruption could change the map of the world.
Kilimanjaro is the highest point in Africa.

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