Volcanoes are caused by sudden movements occurring in the Earth’s interior. Classification of volcanoes based on the frequency of eruptions & based on shape are discussed below
Classification of Volcanoes
Classification of volcanoes based on the frequency of eruptions:
- Active volcanoes are those which have erupted in the recent past and are likely to erupt in the future.
- There are about 550 known active volcanoes.
- Some active volcanoes are Mt Etna in Italy and Mauna Loa in Hawaii.
- Volcanoes which have not erupted in the recent past but can become active at any time are known as dormant volcanoes.
- Dormant volcanoes are also known as ‘sleeping volcanoes’.
- Some dormant volcanoes are Mt Kilimanjaro in Africa and Mt Vesuvius in Italy.
- Volcanoes which have not erupted in the present geological period and are not likely to erupt in the future are known as extinct volcanoes.
- Mt Aconcagua in South Africa and Mt Kenya in Africa are considered extinct volcanoes.
Classification of volcanoes based on shape:
Central volcano: This volcano is formed when debris and lava erupt out forming a symmetrical volcano.
Fissure volcano: This volcano throws out lava and fragments of rocks through fissures or cracks on the Earth’s surface. Instead of building a cone, the cracks distribute lava over a vast area. The Columbian Plateau was formed by a fissure eruption.
Shield volcano: When a volcano emits large quantities of hot lava, a large shield-like structure is spread over large parts of the Earth. Mauna Loa in Hawaii Islands is a shield volcano.
Conical volcano: Because of repeated eruptions, a volcano may acquire a cone-shaped structure. These volcanoes usually have steep slopes. A conical volcano is also known as a composite volcano. Mt Fuji in Japan is an example of a conical volcano.
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A volcano is a vent or an opening in the Earth’s crust from which hot magma erupts from the interior of the Earth. Volcanoes are generally caused because of the following reasons. Read more