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How are volcanoes classified based on the periodicity of their eruptions?

A volcano is a place where gases, ashes and/or molten rock material i.e., lava escape to the ground. The layer below the solid crust is a mantle. It has a higher density than that of the crust. It is from this that the molten rock materials find their way to the surface. The material in the upper mantle portion is called magma. When the magma is out from the volcanic mountain then it is termed as Lava. It may also happen when the plates move apart.

Volcanoes are classified into three on the basis of periodicity.

i. Active volcano

ii. Dormant volcano

iii. Extent volcano

• Active volcano

These are volcanoes which continuously eject the lava, gaseous and fragmented minerals. These types of volcanoes are found in Mount St. Helens in the United States.

• Dormant volcano

The volcanoes which don't show any type of volcanic activity over a long period of time and it is known as a dormant volcano. Sometimes there can be a sudden explosion which is dangerous to the life that is near that mountain. Mt. Fuji in Japan is the and

• Extent volcano

These are volcanoes which have permanently stopped ejecting lava. In these types, volcanoes have permanently extinct. These are also known as a dead volcano.

Mt. Kilimanjaro and Tanzania is the extent volcano.