Natural disasters can be different. These include a volcanic eruption. Every day 8-10 known volcanoes erupt in the world. Most of them go unnoticed, as there are many underwater volcanoes among the active and erupting volcanoes.
What is a volcano
A volcano is a geological formation on the surface of the earth's crust. In these places, magma comes to the surface and forms lava, volcanic gases and stones, which are also called volcanic bombs. Such formations received their name from the name of the ancient Roman god of fire Vulcan.
Volcanoes have their own classification according to several criteria. According to their shape, it is customary to divide them into thyroid, stratovolcanoes, cinder cones and domed ones. They are also divided into terrestrial, underwater and subglacial according to their location.
For the average layman, the classification of volcanoes by their degree of activity is much more understandable and interesting. There are active, dormant and extinct volcanoes.
An active volcano is a formation that has erupted in a historical period of time. Inactive volcanoes are considered asleep, on which eruptions are still possible, and those on which they are unlikely are considered extinct.
However, volcanologists still do not agree on which volcano should be considered active and therefore potentially dangerous. The period of activity at a volcano can be very long in time and can last from several months to several million years.
Why does the volcano erupt
A volcanic eruption is, in fact, the emergence of incandescent lava flows on the surface of the earth, accompanied by the release of gases and ash clouds. This is due to the gases accumulated in the magma. Among them are water vapor, carbon dioxide, sulfur dioxide, hydrogen sulfide and hydrogen chloride.
Magma is under constant and very high pressure. This is why gases remain dissolved in the liquid. Molten magma, displaced by gases, travels through cracks and enters the rigid layers of the mantle. There it melts weak points in the lithosphere and splashes out.
The magma released to the surface is called lava. Its temperature can exceed 1000 ° C. Some volcanoes erupt when they erupt, throwing ash clouds that rise high into the air. The explosive power of these volcanoes is so great that huge blocks of lava the size of a house are thrown out.
The eruption process can last from several hours to many years. Volcanic eruptions are classified as geological emergencies.
Today there are several areas of volcanic activity. These are South and Central America, Java, Melanesia, Japanese, Aleutian, Hawaiian and Kuril Islands, Kamchatka, the northwestern part of the United States, Alaska, Iceland and almost the entire Atlantic Ocean.