What are volcanoes? Hot streams of molten lava sloshing out of the bowels of the Earth, and at the same time clouds of ash, hot steam. The spectacle, of course, is breathtaking, but where does it come from? What are the largest volcanoes on our planet? Where are they?
Origin and varieties of volcanoes
Under the thick layer of the earth's crust is magma - a molten substance of great temperature and under great pressure. Magma contains minerals, vaporous water and gases. When the pressure gets too high, the gases push the magma upward through weak points in the earth's crust. The surface layer of the Earth rises in the form of a mountain, and eventually the magma erupts.
Erupting magma is called lava, and a mountain high with a hole is called a volcano. The eruption is accompanied by emissions of ash and steam. Lava moves at over 40 km/h, with a temperature of around 1000 degrees Celsius. Depending on the nature of the eruption and accompanying phenomena, volcanoes are divided into numerous types. For example, Hawaiian, Plinian, Peleian and others.
Poas it flows out, the lava solidifies and builds up in layers, creating the shape of a volcano. So, there are volcanoes of a cone shape, gentle, domed, stratified or layered, as well as complex shapes. In addition, they are divided into active, dormant and extinct depending on the degree of activity of eruptions.
Large volcanoes of the world
There are approximately 540 active volcanoes all over the world, the number of extinct ones is even greater. All of them are located mainly in the Pacific, East African, Mediterranean fold zones. The greatest activity is manifested in the regions of South and Central America, Kamchatka, the Japanese, Aleutian Islands, and Iceland.
Only in the Pacific belt there are 330 active volcanoes. Large volcanoes are located in the Andes, on the Asian islands. In Africa, the highest is Kilimanjaro, located in Tanzania. This is a potentially active volcano that can wake up at any moment. Its height is 5895 meters.
Two of the world's volcanic giants are located on the territory of Chile and Argentina. They are considered the highest on Earth. Ojos del Salado is dormant, having erupted in 700 AD, although it occasionally emits water vapor and sulfur. Argentine Llullaillaco is considered active, the last time it erupted only in 1877.
The world's largest volcanoes are presented in the table.
| Name | Location | Height, m | Year of eruption |
| Ojos del Salado | Andes, Chile | 6887 | 700 |
| Llullaillaco | Andes, Argentina | 6739 | 1877 |
| San Pedro | Andes, Chile | 6145 | 1960 |
| Catopahi | Andes, Ecuador | 5897 | 2015 |
| Kilimanjaro | Tanzania, Africa | 5895 | Unknown |
| Misty | Andes, Peru | 5822 | 1985 |
| Orisaba | Cordillera, Mexico | 5675 | 1846 |
| Elbrus | Caucasus Mountains, Russia | 5642 | 50 |
| Popocatepetl | Cordillera, Mexico | 5426 | 2015 |
| Sangai | Andes, Ecuador | 5230 | 2012 |
Pacific Ring of Fire
The waters of the Pacific Ocean hide three lithospheric plates. Their outer edges go under the lithospheric plates of the continents. Along the entire perimeter of these joints is locatedPacific Ring of Fire - small and large volcanoes, most of which are active.
The ring of fire starts from Antarctica, passes through New Zealand, the Philippine Islands, Japan, the Kuriles, Kamchatka, stretches along the entire Pacific coast of North and South America. In some places, the ring is breaking, such as near Vancouver Island and California.
Large volcanoes of the Pacific belt are located in the Andes (Orizabo, San Pedro, Misti, Cotopaxi), Sumatra (Kerinchi), Ross Island (Erebus), Java (Semeru). One of the most famous - Fujiyama - is located on the island of Honshu. Krakatoa volcano is located in the Sunda Strait.
The Hawaiian Islands archipelago is of volcanic origin. The largest volcano is Mauna Loa with an absolute height of 4169 meters. In terms of relative height, the mountain bypasses Everest and is considered the highest peak in the world, this value is 10,168 meters.
Mediterranean belt
The mountainous regions of Northwest Africa, southern Europe, the Mediterranean, the Caucasus, Asia Minor, Indochina, Tibet, Indonesia and the Himalayas make up the Mediterranean Fold Belt. Active geological processes are taking place here, one of the manifestations of which is volcanism.
The largest volcanoes of the Mediterranean belt are Vesuvius, Santorin (Aegean Sea) and Etna in Italy, Elbrus and Kazbek in the Caucasus, Ararat in Turkey. Italian Vesuvius consists of three peaks. Cities suffered from its powerful eruption in the first century ADHerculaneum, Pompeii, Stabia, Oplontia. In memory of this event, Karl Bryullov painted the famous painting "The Last Day of Pompeii".
The stratovolcano Ararat is the highest point in Turkey and the Armenian Highlands. Its last eruption took place in 1840. It was accompanied by an earthquake that completely destroyed the neighboring village and monastery. Ararat, like the Caucasian Kazbek, consists of two peaks, which are separated by a saddle.
Large volcanoes of Russia (list)
On the territory of the Russian Federation, volcanoes are located in the Kuriles, Kamchatka, the Caucasus and Transbaikalia. They make up about 8.5% of all volcanoes in the world. Many of them are considered extinct, although the sudden eruptions of Bezymyanny in 1956 and the Academy of Sciences in 1997 proved the relativity of this term.
The largest volcanoes are located in Kamchatka and the Kuril Islands. The highest in all of Eurasia (among the existing ones) is Klyuchevskaya Sopka (4835 meters). Its last eruption was recorded in 2013. There are very small volcanoes in the Primorsky and Khabarovsk Territories. For example, the height of Baranovsky is 160 meters. Berg (2005), Ebeko (2010), Chikurachki (2008), Kizimen (2013) and others have been active over the past decade.
The largest volcanoes in Russia are presented in the table.
| Name | Location | Height, m | Year of eruption |
| Elbrus | Caucasus | 5642 | 50 |
| Kazbek | Caucasus | 5033 | 650 BC e. |
| Klyuchevskaya Sopka | Kamchatsky Krai | 4835 | 2013 |
| Stone | Kamchatsky Krai | 4585 | Unknown |
| Ushkovsky | Kamchatsky Krai | 3943 | 1890 |
| Tolbachik | Kamchatsky Krai | 3682 | 2012 |
| Ichinskaya Sopka | Kamchatsky Krai | 3621 | 1740 |
| Kronotskaya Sopka | Kamchatsky Krai | 3528 | 1923 |
| Shiveluch | Kamchatsky Krai | 3307 | 2014 |
| Zhupanovskaya Sopka | Kamchatsky Krai | 2923 | 2014 |
Conclusion
Volcanoes are the consequences of active processes that occur inside our planet. They form in hot spots of the earth's crust, where the crust does notwithstands pressure and high temperatures. The consequences of a volcanic eruption can be quite serious, as they are accompanied by emissions of ash, gases, and sulfur into the atmosphere.
Associated phenomena of an eruption are often earthquakes and faults. The flowing lava has such a high temperature that it instantly affects biological organisms.
However, in addition to the destructive effect, volcanoes also have the opposite effect. Lava that has not come to the surface can lift sedimentary rocks to form mountains. And the island of Surtsey became a consequence of the eruption of an underwater volcano in Iceland.
