Volcanoes are on all continents except Australia, even on Antarctica. The main location of the volcano is mainly located in seismically active zones, faults of the earth’s crust and at the joints of tectonic plates. Active volcanoes are located in those parts of the world that are also most prone to earthquakes, where the most movement underground.
Volcanic eruption, danger of eruption, lava, volcanic bombs, ashes, mud flows, human behavior in the danger zone.
Volcanoes are not only active, but also the so-called sleeping volcanoes. Moreover, the latter are no less dangerous, as they can wake up at any time. The most active volcanoes erupt once every few years, and all active volcanoes every 10-15 years.
, but also fall into a hot stream, the temperature of which is several hundred degrees. Being near the crater or on the slope of the volcano is dangerous not only during the eruption, but also because various toxic gases are often burst from the ground. Such gas outlets are called fumaroles. Often carbon dioxide, which is colorless and odorless, accumulates in depressions and can cause severe, often fatal poisoning. Often from the cracks in the ground jets of hot steam burst out.
Dangers of volcanic eruption and human behavior in the danger zone.
Although in most cases it is possible to escape or even get away from basaltic lava flows, they flow non-stop until they reach the bottom of the valley or ultimately cool down. They destroy or cover everything in their path. Lava flows are probably the least danger to life during an eruption, since a normal healthy person can leave it.
Volcanic bombs, ranging in size from small pebbles to huge pieces of stone and ductile hot lava, can fly over considerable distances. Rain from volcanic ash can cover much larger areas, a certain amount of volcanic dust rises to a great height and spreads around the world, affecting the weather. When evacuating from the area adjacent to the volcano, some helmets can give some protection like those worn by construction workers, motorcyclists or jockeys. At a greater distance, where evacuation may not be necessary, protection should be provided from the effects of ash and the accompanying rain.
But perhaps even more terrible phenomenon can be called the falling of hot ash, which not only destroys everything around, but can also fill entire cities with a thick layer. If you fall into such an ashfall, it is almost impossible to escape. Volcanic ash is actually not ash, but a powdery stone thrown from a volcano in a cloud of steam and gases. This abrasive, irritating and heavy substance can break roofs under its weight. It can strangle crops, block roads and waterways, and in combination with toxic gases can also cause lung complications in children, the elderly, and those with lung diseases.
In order to poison a healthy person, a sufficient concentration of toxic gases is only very close to the eruption. But when the sulfur dioxide contained in the ash cloud combines with rain, sulfuric acid (and sometimes others) is formed in such concentrations that it can cause burns to the skin, eyes and mucous membranes. Wear goggles (ski goggles or a snorkeling mask will hermetically close your eyes but not anti-sun). Use a damp cloth to cover the mouth and nose, or industrial face masks, if any. Having reached the shelter, take off your clothes, thoroughly wash those parts of the body that were open, and rinse your eyes with clean water.
A cloud of gas and dust can slide down the slope of the volcano at a speed of more than 160 km / h. It is red-hot and moves so fast that it is impossible to escape from it. This phenomenon is often called a scorching cloud. If there is no solid underground shelter nearby, the only chance to survive is to dive under water and stay there, holding your breath for about half a minute, until a hot cloud passes.
During mud eruptions, powerful mud flows like mudflows also occur. The volcano can melt and snow and cause a water-ice mud or mudflow mixed with earth. It can travel at speeds up to 100 km / h with the most devastating effect, as was the case in Colombia in 1985. In a narrow valley, its height can reach 30 meters.
Streams are dangerous and long after the main eruption and are a potential threat, even when the volcano is sleeping, if at the same time it gives enough heat to melt the water, which will be delayed by ice barriers. Heavy rains can lead to the destruction of these ice dams. When evacuating a car, remember: ashes can make roads slippery, even if it does not block them. Avoid Valley Routes That May Become Mudflow Routes.
Based on materials from the book Encyclopedia of Survival.
Chernysh I. V.