Volcanoes are huge conical mountains that explode and spew out the masses of lava all over causing a massive destruction of living and nonliving environment. People are really curious about the types of this disastrous natural event. In terms of activity, volcanoes can be divided into basic 3 categories.
1) Still active volcano: This one is still erupting out the hot lava from the huge crater.
2) Dormant volcano: This is temporarily inactive but not fully extinct
3) Extinct volcano: It is never likely to erupt again. Besides this general classification, there are further four types of volcanoes according to the shape and formation.
They are briefly described below.
Cinder Cones:
These are the simplest type of volcanoes formed by the eruption of thin, runny lava. The gas-charged lava is violently blown into the air and it breaks into fragments and solidifies causing cinder to fall around vent forming an oval or a circular cone. They have craters of a bowl shape and rise up to 1 thousand feet or above their surrounding. Eruptions tend to be frequent but relatively gentle. The numerous cinder cones are found at western north America.
Composite Volcanoes or Stator-Volcanoes:
These are steep-sided, symmetrical cones. They rise above eight thousand feet from their surroundings. They are generally formed from alternating layers of larva flow, volcanic ash, and cinder. An essential component of composite volcanoes is the conduit system through which the magma from the innermost part of the earth comes to the surface. Most of the beautiful mountains in the world like Mt. Fuji in Japan, Mt. Shasta in California, Mt. Rainier in Washington and many other are composite volcanoes.
Shield Volcanoes:
They are almost formed by the slow accretion of highly fluid lava called Basalt Lava. The flow of lava when cools it builds a broad, gentle slope cone of flat and dome shape. Lave erupts from vents along flanks of the cone. Some of the largest volcanoes like Mauna loa volcano in Hawaii, are shield volcano. This volcano projects 13,677 feet above sea level.
Lava Domes:
They are formed by small, viscous flow of lava that cools and piles up. They expand within and grows larger. They occur within crater or on flanks of large composite volcanoes. Mont Pelee in Martinique, Mono dome in California are examples of lava domes. Hence according to the term of activity, there are 3 and as per the shape and formation, there are 4 types of volcanoes in the world.