For centuries, people interested in the phenomenon of volcanic eruptions.They are considered to be the most unpredictable creatures of nature.Sometimes dormant without causing any attention, sometimes to fill in all the news strip and substantially alter the habitual way of life of civilians, volcanoes are a formidable element, from time to time remind yourself.On what are the types of volcanoes, and will be discussed in this article.
What is it?
What is a volcano?The word has its roots in ancient Roman mythology - is the name of the Roman pantheon wore lord fire god Vulcan.In Greek mythology, it corresponds to the god Hephaestus, the blacksmith.
From a scientific point of view of the volcano - a tectonic fault in the earth's crust, enabling magma, located between the crust and the core to surface.When faced with an environment of magma formed by molten lava and gas, which is released from the fumaroles - holes on the slopes of the volcano and near its crater.The eruption is accompanied by the emission of ash into the air.Cooling down, the lava hardens, so the nature of the rocks around the volcano is different from the nature of the other rock formations.
To measure the strength of the eruption using a special scale VEI (Eng. Volcanic Explosivity Index) - index of volcanic explosivity.Scale evaluates each eruption from zero to eight points, based on the height of the column and the number of ashy ejected ash.
Types of volcanic eruptions
Types shared on various grounds.The simplest and most common classification is based on the criterion of activity.Thus, the release:
- Active volcanoes, which include those on the eruption which have reliable historical sources.
- dormant volcano, not active in the historical time period, but the eruption of which scientifically probable.
- extinct volcano, the eruption of which is practically impossible.
also highlights kinds of volcanoes, based on their shape, the character of the eruption, the crater type and so on.There are mud volcanoes, where instead of lava on the surface there are mud and methane, and underwater, located on the ocean floor.
Active volcanoes
each volcanic eruption is a significant event and attracts the attention of many media.Extinct and active volcanoes attract attention from both scientists and tourists from supporters and extreme rest.
Among the most active volcanoes can be called the volcano Merapi in Indonesia, Eyjafjallajokull in Iceland, Mauna Loa in Hawaii, the Philippines Tal, Fuego and Santa Maria in Guatemala, Sakurajima in Japan, and many others.Widely known also received Sicilian volcano Mount Etna, Vesuvius, Naples, Pompeii brought death, as well as Fuji, often referred to in the Japanese culture.
should be noted and Kilimanjaro - the highest volcano in the world and the highest point in Africa, located in the eastern part of the continent.Kilimanjaro is not currently considered to be an extinct volcano, although it too active do not call.
Volcano Mountain
extinct volcanoes of the world, the list of which no less rich in interesting specimens in wide circles often perceived as ordinary mountain.These eruptions occurred in prehistoric times, but, according to a scientific theory, may happen again, though with a small probability.However, to calculate the probability of this is practically impossible, any figures given in this regard, do not have significant specificity.
Among the most famous extinct volcanoes can be distinguished:
- Ararat - a volcano in eastern Turkey, part of the mountain system of the Armenian highlands.It has two cones, which are called Big and Little Ararat.Great Ararat is also the highest point of the plateau.
- Aconcagua - the highest extinct volcano in the world.At the same time is the highest point of America (both North and South), and the highest point in the West and the Southern Hemisphere.
- Elbrus - many sources call it an extinct volcano.Elbrus is located north of the Caucasus Mountains and is the highest point in Russia.
- Kazbek - volcano in the eastern part of the Central Caucasus, on the border between Russia and Georgia.
- Karadag - mining and volcanic massif in the Crimea.Its name means "black mountain".Karadag has several craters and fumaroles frozen.
This is the most famous extinct volcanoes in the world.The list goes on many other volcanoes, of which in nature are innumerable.
asleep or hiding?
in volcanology assumed that if in the past 100 000 years the volcano has not erupted even once, it is asleep.Some researchers call them supervolcano.These conclusions are based on the fact that the dormant volcanoes of the world little explored, and it is fraught with a huge eruption which could easily destroy a large part of all living things on the planet.
Conclusion
Overall extinct, existing and dormant volcanoes, there are many.On the part of the scientists there is a lot of controversy over the exact number.The number can range from 500 to 1700, depending on the different points of view, the criteria for which are separated by types of volcanoes.In any case, it is undeniable that volcanoes play an important role in human life, tourism, culture, people, mythology.And sometimes they become factors of natural disasters that may directly affect people's lives.
