A volcano is a rupture (a sudden bursting or breaking) in the crust of a planetar-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface.
On Earth, volcanoes are most often found where tectonic plates are diverging or converging, and most are found underwater.
For example, a mid-ocean ridge, such as the Mid-Atlantic Ridge, has volcanoes caused by divergent tectonic plates whereas the Pacific Ring of Fire has volcanoes caused by convergent tectonic plates.
Volcanoes can also form where there is stretching and thinning of the crust's plates, such as in the East African Rift and the Wells Gray-Clearwater volcanic field and Rio Grande Rift in North America.
Volcanoes are usually not created where two tectonic plates slide past one another.
While most volcanoes are created by geological activity at tectonic plate boundaries, the Hawaii hotspot is located far from plate boundaries. Hot-spot volcanism can occur in the middle of tectonic plates.
Hot-spot volcanism occurs near unusually hot parts of Earth's mantle, the layer of the planet below the crust. The upwelling of molten rock creates volcanoes that spew out lava (magma that reaches Earth's surface).
Magma is the term used to denote the molten rocks and related materials seen inside earth. Once this magma comes out to the earth surface through the vent of a volcano, it is called as the Lava.
The 5 countries with the most volcanoes: United States (173), Russia (166), Indonesia (139), Iceland (130), Japan (112).
DistributionMost of the volcanoes in the world are found in three well defined belts:
1) The Circum-Pacific BeltMost of the high volcanic cones and volcanis mountains are found in Circum-Pacific Belt (The Pacific Ring of Fire), where there is active subduction of the Pacific, Nazca, Cocos, and juan de fuca plates.
One good example is the volcanic islands of Sumatra and Java, which lies over the subduction zone between the Australian plate and the Eurasian plate.
|Mount St Helens
La Garita Caldera
|Papua New Guinea|
|Volcan de Fuego||Guatemala|
2) Himalayan BeltThe African continental plate thrust into the Eurasian continental plate 30 million years ago and the Indian continental plate thrust into the Eurasian continental plate 50 million years ago.
This gave rise to a chain of folded mountains along the boundaries of these plates.
|Atlas-Alpine Caucasus and Himalayan Belt|
|Italy (Alpine Belt)|
|No Active Volcano||Himalayan Belt|
3) The African Rift Valley BeltA narrow zone, the rift is a developing divergent tectonic plate boundary where the African Plate is in the process of splitting into two tectonic plates, called the Somali Plate and the Nubian Plate.
|East African Belt|
|Marion Island||South Africa|
|Ol Doinyo Langai||Tanzania|
|Mount Fogo||Cape Verde|
India's only active volcanoe is located in Barren island of Andaman, which is also the only confirmed active volcano in South Asia.
Major Volcanoes around the WorldHere is a list of major volcanoes around the world, their location, country, heights and prominent features:
|Largest Volcanoes In the World|
|Volcanoes||Location & Feature||Height (m)|
|Mauna Loa||Hawaii, U.S.A||9170|
|Teide||Canary Islands, Spain||7500|
|Piton des Neiges||Reunion, France||7071|
|Ojos del Salado||Argentina/Chile - Highest active volcano on Earth||6893|
|Llullaillaco||Argentina/Chile - Second highest active volcano on Earth||6739|
|Nevado Sajama||Bolivia - The highest peak of Bolivia||6542|
|Chimborazo||Ecuador - Farthest point from Earth's centre||6267|
|Cotopaxi||Ecuador - Second highest in Ecuador||5897|
|Kilimanjaro||Tanzania - Highest volcano outside South America; the highest peak in Africa||5895|
|Cayambe||Ecuador - Third highest in Ecuador||5790|
|Mount Elbrus||Russia - Highest volcano in Eurasia; the highest peak in Russia||5642|
|Pico de Orizaba||Mexico -Highest volcano in North America; the highest peak in Mexico||5636|
|Mount Damavand||Iran - Highest volcano within Asia; the highest peak in Iran||5610|
|PopocatÚpetl||Mexico - Second highest volcano in North America||5426|
|Iztaccihuatl||Mexico ? Third highest volcano in North America||5230|
|Mount Kenya||Kenya - Second highest volcano in Africa; the highest mountain in Kenya||5199|
|Mount Ararat||Turkey/Armenia - The highest mountain in Turkey||5137|
|Mount Kazbek||Georgia - Highest volcano in Georgia||5047|
|Mount Bona||Alaska - highest volcano in the United States||5005|
|Klyuchevskaya Sopka||The Kamchatka Peninsula, Russia - highest active in Eurasia; the highest mountain in Siberia||4750|
|Mount Karisimbi||Rwanda/Democratic Republic of Congo - highest mountain in Rwanda||4507|
|Mount Rainier||Washington - highest volcano in the contiguous United States||4392|
|Mount Giluwe||Papua New Guinea - highest volcano in Australasia and Pacific islands||4368|
|Volcan Tajumulco||Guatemala - highest mountain in Central America||4220|
|Mauna Kea||Hawaii, United States - World's tallest mountain from base to summit||4205|
|Mount Sidley||Antarctica - Highest volcano in Antarctica||4181|
|Mount Cameroon||Cameroon - Highest mountain in Cameroon||4095|
|Mount Aragats||Armenia - Highest mountain in Armenia||4095|
|Mount Kerinci||Sumatra, Indonesia - Highest volcano in Indonesia; the highest mountain in Sumatra||3805|
|Mount Fuji||Chubu Region, Honshu ? Highest mountain in Japan||3776|
|Mount Rinjani||Lombok, Indonesia - Second-highest volcano in Indonesia||3726|
|Teide||Tenerife, Canary Islands - the highest peak in the Atlantic Islands and Spain||3718|
|Semeru||Java, Indonesia - Highest mountain in Java||3676|
|Emi Koussi||Chad - Highest mountain in Chad & the Sahara||3415|
|Mount Etna||Sicily - Active; highest volcano in Western Europe; the highest peak in Italy south of the Alps||3329|
|Haleakala||Maui, Hawaii - Highest peak of Maui||3055|
|Mount Agung||Bali, Indonesia - Highest mountain in Bali||3031|
|Pico BasilÚ||Bioko, Equatorial Guinea - Highest mountain in Equatorial Guinea||3011|
|Mount Zuqualla||Oromia Region - Highest volcano in Ethiopia||2989|
|Mount Apo||Mindanao - Highest mountain in the Philippines||2954|
|Mount Shishaldin (Sisquk)||Unimak Island, Alaska - Highest mountain in the Aleutian Islands||2857|
|Mount Ruapehu||North Island - Highest volcano in New Zealand||2797|
|Mawson Peak||Heard Island - Highest mountain in Australia||2745|
|Pico||Azores - Highest mountain in Portugal||2351|
|Beerenberg||Jan Mayen, Norway - Highest volcano in Norway||2277|
|Taal Volcano||Batangas, Philippines - Smallest volcano on earth||311|
|Pali-Aike volcanic field||Argentina - Chile border region||180|