For centuries, people have been interested in the phenomenon of volcanic eruptions. They are rightfully considered the most unpredictable creations of nature. Sometimes inactive, not causing any attention, sometimes filling all the news feeds and significantly changing the usual way of life of the civilian population, volcanoes are a formidable element that from time to time reminds of itself. About what types of volcanoes are, and will be discussed in this article.
What it is?
What are volcanoes? The word has its roots in ancient Roman mythology - this name in the Roman pantheon was the lord of fire, the god Volcano. In ancient Greek mythology, the blacksmith Hephaestus corresponded to him.
From a scientific point of view, a volcano is a tectonic fault in the surface of the earth's crust, which allows magma located between the crust and core to surface. In a collision with the environment, magma forms lava and gas, which is released from fumaroles - holes on the slopes of the volcano and near its crater. The eruption is accompanied by the release of ash into the air. As the lava cools, the nature of the stones around the volcanoes differs from the nature of other rock formations.
To measure the eruption force, a special VEI scale is used (the English Volcanic Explosivity Index) - an indicator of volcanic explosivity. The scale estimates each eruption from zero to eight points, based on the height of the ash column and the amount of ash ejected.
Varieties of volcanoes
Types of volcanoes are divided according to a variety of signs. The simplest and most common classification is based on activity criteria. Thus, allocate:
- Active volcanoes, which include those whose eruption has reliable historical sources.
- Sleeping volcanoes that have not been active in the historical time period, but whose eruption is scientifically probable.
- Extinct volcanoes, the eruption of which is almost impossible.
Types of volcanoes are also distinguished based on their shape, nature of the eruption, type of crater, and more. There are mud volcanoes, where instead of lava, dirt and methane come out to the surface, and underwater, located at the bottom of the oceans.
Active volcanoes
Each volcanic eruption is a significant event and attracts the attention of many media. Extinct and active volcanoes attract attention both from scientists and from tourists and supporters of extreme relaxation.
Among the most active active volcanoes are the Merapi volcano in Indonesia, Eyyafyatlayokudl in Iceland, Mauna Loa in Hawaii, Tal in the Philippines, Fuego and Santa Maria in Guatemala, Sakurajima in Japan and many others. The Sicilian volcano Etna, the Neapolitan Vesuvius, which brought about the death of Pompeii, as well as Fuji, often mentioned in Japanese culture, was also widely known.
Kilimanjaro, the highest volcano in the world and the highest point in Africa, located in the eastern part of the continent, should also be noted. Kilimanjaro is not currently considered an extinct volcano, although it is not called active either.
Volcano mountain
Extinct volcanoes of the world, list which no less rich in interesting specimens, in wide circles they are most often perceived as ordinary mountains. Their eruptions occurred in prehistoric times, but, according to scientific theory, they can recur again, albeit with a small probability. Nevertheless, it is practically unrealistic to calculate this probability; any figures given on this occasion have no significant specifics.
Among the most famous extinct volcanoes are:
- Ararat is a volcano in eastern Turkey, part of the mountain system of the Armenian Highlands. It has two cones, which are called Big and Small Ararat. Greater Ararat is at the same time the highest point of the highlands.
- Aconcagua is the highest extinct volcano in the world. At the same time, it is the highest point in America (both North and South) and the highest point in the Western and Southern Hemisphere.
- Elbrus - many sources call it an extinct volcano. Elbrus is located north of the Greater Caucasus Mountain Range and is the highest point in Russia.
- Kazbek is a volcano in the eastern part of the Central Caucasus, standing on the border of Russia and Georgia.
- Kara-Dag is a mountain-volcanic massif in the Crimea. Its name in translation means "black mountain". Kara-Dag has several craters and frozen fumaroles.
These are the most famous extinct volcanoes in the world. The list can be continued by many other volcanoes, of which there are innumerable in nature.
Sleeping or hiding?
In volcanology, it is generally accepted that if over the past 100,000 years the volcano has not erupted even once, then it is dormant. Some researchers call them supervolcanoes. Such conclusions are based on the fact that sleeping volcanoes of the world are little studied, and this is fraught with one huge eruption, which can easily destroy most of all life on the planet.
Conclusion
In general, there are a lot of extinct, active and sleeping volcanoes. There is a lot of controversy among scientists about the exact amount. The figure can vary from 500 to 1700, depending on various points of view, the criteria by which the types of volcanoes are divided. In any case, it cannot be denied that volcanoes play an important role in human life, in tourism, the culture of peoples, and mythology. And also they sometimes become factors of natural disasters, on which people's lives can directly depend.