Volcanoes are fire-breathing mountains, a place where you can look into the bowels of the Earth. Among them, the active and the extinct are distinguished. If active volcanoes from time to time are active, then information about the eruptions of the extinct has not been preserved in the memory of mankind. And only the structure and rocks composing them allow us to judge their turbulent past.
An intermediate position is occupied by sleeping or asleep volcanoes. They are characterized by a lack of activity for many years.
Sleeping volcanoes
The division of volcanoes into dormant and active is very arbitrary. People may simply not be aware of their activity in the not-so-distant past.
Sleeping are, for example, the famous volcanoes of Africa: Kilimanjaro, Ngorongoro, Rungwe, Mengai and others. They have not been erupted for a long time, but light streams of gas rise above some. But knowing that they are in the zone of the Great East African graben system, it can be assumed that at any moment they can wake up and show themselves in all their might and danger.
Dangerous calm
Asleep volcanoes can be very dangerous. A saying about a quiet pool and the devils in it is well suited to them. The history of mankind remembers many cases when a volcano, long considered asleep or even extinct, woke up and caused a lot of troubles to people living in its vicinity.
The most famous example is the famous eruption of Vesuvius, which destroyed, in addition to Pompeii, several more cities and many villages. The life of Pliny the Elder, a famous ancient military leader and naturalist, was cut short precisely in connection with him.
The interrupted sleep of volcanoes
The Ruiz Volcano in the Colombian Andes has been considered asleep since 1595. But on November 13, 1985, he denied this, having erupted in a series of explosions, one stronger than the other. Snow and ice located in the crater and on the slopes of the volcano began to melt rapidly, forming powerful mud-stone flows. They poured into the valley of the La Gunilla River and reached the city of Armero, located 40 km from the volcano. A stream of dirt and stones hit the city and surrounding villages with a raging mess of 5-6 m thick. About 20 thousand people died, Armero became a huge mass grave. Only those residents who at the beginning of the eruption climbed the nearest hills were able to escape.
The release of gas from the vents of the Nyos volcano caused the death of more than 1, 700 people and a large number of cattle. But he was considered long extinct. A lake even formed in his crater.
Volcanoes of Kamchatka
Kamchatka Peninsula is the center of a large number of active and sleeping volcanoes. It would be wrong to consider them extinct, because here is the boundary of the collision of lithospheric plates, which means that any activity in tectonic movements can awaken the asleep formidable forces of nature.
Bezimyanny volcano, located south of Klyuchevskaya Sopka, was long considered an extinct. However, in September 1955 he woke from a dream, an eruption began, clouds of gas and ash rose to a height of 6-8 km. However, this was only the beginning. A prolonged eruption reached a maximum on March 30, 1956, when a powerful explosion sounded, blowing the top of the volcano, forming a deep crater with a diameter of up to 2 km. The explosion destroyed all the trees at a distance of 25-30 km in the district. A giant cloud, consisting of hot gases and ash, rose to a height of 40 km! Small particles fell out at great distances from the volcano itself. And even at a distance of 15 km from Bezymyanny, the thickness of the ash layer was half a meter.
As with the eruption of the Ruiz volcano, a stream of mud, water and stones formed, which swept to the Kamchatka River, which is almost 100 km.
The asleep volcanoes of Kamchatka are very dangerous, because they look like the infamous Vesuvius, Mont Pele (Martinique Island), Katmay (Alaska). They sometimes happen explosions, which in more densely populated areas would be a real disaster.
An example is the eruption of Shiveluch in 1964. The power of the explosion can be judged by the size of the crater. Its depth was 800 m and its diameter was 3 km. Volcanic bombs weighing up to 3 tons scattered to a distance of 12 km!
Such powerful eruptions in the history of Shiveluch happened more than once. At the small village of Klyuchi, archaeologists managed to unearth a settlement, covered with ashes and stones several centuries ago, even before the Russians arrived in Kamchatka.
Threat to humanity
Some scientists believe that it is asleep volcanoes that can cause a global catastrophe that will destroy humanity. However, they talk about long-extinct giants such as Yellowstone in North America. The supervolcano, after its last eruption, leaving the caldera 55 km to 72 km, is in the "hot spot" of the planet, where magma is close to the earth's surface.
And there are a lot of such giants sleeping or close to awakening on Earth.
