Active or active volcanoes are the subject of many volcanologists discussions. Scientists express their different views and ambiguous points of view about this definition. Some propose to refer to active volcanoes those that are erupting 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, differ greatly. It may be 200 or 3000 years old.
There is a program to study world volcanism. It is carried out by the world's largest research and museum complex - the Smithsonian Institute. Participants in this program decided that volcanoes should be considered active if their eruption occurred during the last 10, 000 historical years.
At present, there are about 1, 500 active volcanoes on the globe. Each year, about 50 of them erupt, with a large amount of poisonous gases, ash, steam, and lava emitted into the atmosphere. Accompanied by earthquakes, they can cause irreparable damage. In 2011, active world volcanoes erupted in Japan, Chile, Italy, Iceland and Indonesia. Most active or active volcanoes are concentrated in Hawaii and Alaska.
Volcanoes, sleeping for more than a decade, can suddenly wake up, as it did in the south in the central part of Chile. The highest volcano in Europe, Etna, located on the island of Sicily, spewed lava flows last summer.
Active volcanoes attract much attention of tourists. Being in the uninhabited part of the Virunga National Park of the Democratic Republic of Congo, not posing a danger to the endangered mountain gorilla species, in the fall of 2011, Nyamulangira volcano became active. He attracted a large number of tourists with his breathtaking view of slowly flowing rivers of red-hot lava. It is a beautiful and yet terrifying sight. Nature does not tire of periodically reminding about her rights and that she is not a lifeless object of consumption. These reminders occur in the form of cataclysms, one of the reasons for which are active volcanoes of the world.
The powerful Pacific ring of active volcanoes includes a large link in Kamchatka with 28 and 39 Kuril volcanoes. A large number of them are hidden under water. In an inactive state, they look quite peaceful, but do not forget about the processes occurring in their depths. One of the largest Kamchatka active volcanoes is Shiveluch, but the highest active volcano in Eurasia is located in the Klyuchevskaya volcano. From the very beginning of its operation and up to our time, there are no long periods of its attenuation. The ideally symmetrical snow-covered volcano is often called the “mountain of fire”. Its height fluctuates after the next eruption. The last, which occurred in 2009, brought its peak to the level 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 according to various data, the altitude is from 6880 m to 6908 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 climatic conditions on our planet have changed several times due to active volcanic activity. Animals and plants had to evolve, adapting to these changes.