Active or active volcanoes are the subject of many discussions of volcanologists. Scientists express their different views and ambiguous points of view about this definition. Some suggest to refer to the active volcanoes those whose eruption occurs at the moment, as well as those that show all sorts of signs of activity. This may be increased or abnormal seismicity, as well as an increase in fumarolic activity. For other specialists, active volcanoes are those that erupt in historical time. Different regions monitor volcanic activity at certain time intervals, and they in turn vary greatly. It can be both 200, and 3000 years.
There is a program to study the world's volcanism. It is implemented by the largest research and museum complex in the world - the Smithsonian Institute. Participants in this program agreed that volcanoes should be considered operational if their eruption occurred during the last 10,000 historical years.
At present, there are about 1500 active volcanoes on the Earth. Each year, about 50 of them erupt, with a large amount of toxic gases, ash, steam, and lava emitted into the atmosphere. Accompanied by earthquakes, they can cause irreparable damage. In 2011, the active volcanoes of the world erupted in Japan, Chile, Italy, Iceland and Indonesia. Most active or active volcanoes are concentrated in Hawaii and Alaska.
Volcanoes, asleep for more than a decade, can suddenly wake up, as it was in the south in central Chile. The highest in Europe, the volcano Etna, located on the island of Sicily, erupted lava flows last summer.
Active volcanoes attract great attention of tourists. Being in the uninhabited part of the Virunga National Park of the Democratic Republic of the Congo, without posing a threat to the endangered species of mountain gorillas, in the autumn of 2011 the volcano Nyamulangira was activated. He attracted a large number of tourists with his spectacular view of the slowly flowing rivers of hot lava. This is a beautiful and at the same time a terrible sight. Nature does not tire of periodically reminding about their rights and that it is not a lifeless object of consumption. These reminders occur in the form of cataclysms, one of the causes of which are the active volcanoes of the world.
A powerful Pacific ring of active volcanoes includes a large link of Kamchatka with 28 and 39 Kuril volcanoes. A large number of them are hidden under water. In the inactive state, they look pretty peaceful, but do not forget about the processes taking place in their bowels. One of the largest Kamchatka active volcanoes is Shiveluch, but the highest active volcano in Eurasia is located in the Klyuchevskaya Sopka district . From the very beginning of its operation and until our time, it is not known long periods of its decay. An ideally symmetrical, snow-covered volcano is often called a "fiery mountain". Its height fluctuates after another eruption. The last, which occurred in 2009, brought his peak to a mark of 5000 meters.
Colombian Nevado del Rus is the highest active volcano in the Andes, and Ojos del Salado is the highest in the world. It is located on the border of Chile and Argentina in South America. At its base, its diameter is 30 km, and the height according to various data ranges from 6,880 m to 6,908 m.
Volcanoes can be not only "hot", but also "cold" or mud. In Azerbaijan, their representative is Gobustan, which is considered curative.
Active volcanoes are extremely interesting, which is confirmed by numerous facts. For example, it is known that eruptions accelerate evolutionary processes, and the climatic conditions on our planet have changed many times due to active volcanic activity. Animals and plants had to evolve, adapting to these changes.