For many centuries, people have been interested in such a phenomenon as volcanic eruptions. They are rightfully considered the most unpredictable creations of nature. Sometimes inactive, not causing any attention, sometimes filling all the news pages and significantly changing the habitual way of life of the civilian population, volcanoes are a formidable element that reminds of itself from time to time. About what types of volcanoes are, and will be discussed in this article.
What is this?
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 Vulcan. In ancient Greek mythology, he was associated with the blacksmith god Hephaestus.
From a scientific point of view, a volcano is a tectonic fault in the surface of the earth's crust, enabling the magma between the crust and the core to come to the surface. Upon collision with the environment, hot lava and gas are formed from magma, 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. Cooling down, lava turns to stone, so natureThe rocks around volcanoes are different from the nature of other rock formations.
To measure the force of an eruption, a special scale VEI (Volcanic Explosivity Index) is used - an indicator of volcanic explosiveness. The scale rates each eruption from zero to eight points, based on the height of the ash column and the amount of ash ejected.
Variety of volcanoes
Types of volcanoes are divided according to a variety of criteria. The simplest and most common classification is based on the criterion of activity. Thus, allocate:
- Active volcanoes, which include those about which there are reliable historical sources.
- Sleeping volcanoes that have not been active in the historical time period but are scientifically likely to erupt.
- Extinct volcanoes, almost impossible to erupt.
The types of volcanoes are also distinguished based on their shape, the nature of the eruption, the type of crater, and so on. There are mud volcanoes, where mud and methane come to the surface instead of lava, and underwater ones, 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 the attention of both scientists and tourists and fans of extreme recreation.
Among the most active active volcanoes are Mount Merapi in Indonesia, Eyjafjallajokull 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 the death of Pompeii, and Fujiyama, often mentioned in Japanese culture, were also widely known.
It is impossible not to mention Kilimanjaro - the highest volcano in the world and the highest point in Africa, located in the eastern part of the continent. Kilimanjaro is currently not considered an extinct volcano, although it is not called active either.
Volcano Mountain
Extinct volcanoes of the world, the list of which is no less rich in interesting specimens, in wide circles are most often perceived as ordinary mountains. Their eruptions occurred in prehistoric times, but, according to scientific theory, they can happen again, albeit with a small probability. However, it is almost impossible to calculate this probability, any figures given on this matter do not have 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. Big Ararat is also 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 Hemispheres.
- Elbrus - many sources call it an extinct volcano. Elbrus is located to the northGreater Caucasus 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 with many other volcanoes, of which nature is innumerable.
Sleeping or hiding?
In volcanology, it is generally accepted that if a volcano has not erupted even once in the last 100,000 years, then it is dormant. Some researchers call them supervolcanoes. Such conclusions are based on the fact that the dormant volcanoes of the world are little explored, 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 dormant volcanoes. On the part of scientists, there is a lot of controversy over the exact amount. The figure can vary from 500 to 1700, depending on different 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.
