Formation and types of Volcanoes

By -



 FORMATION OF VOLCANOES :

  • A volcano is an opening in the Earth's crust that allows hot, molten rock (magma), volcanic ash, and gases to escape from the mantle. The mantle is the layer of hot, solid rock that lies between the Earth's crust and the core. When magma reaches the surface, it is called lava.

  • Volcanoes are found all over the world, but they are most common along the edges of tectonic plates.

  • Tectonic plates are large pieces of Earth's Crust that are constantly moving. When two tectonic plates move apart or diverge in two different directions, magma can rise up to mantle and fill the gap between the spaces.

  • This is how volcanoes are formed at mid- oceanic ridges. 


  • When two tectonic plates come together, one plate may be forced down into the mantle. As the plate sinks, it heats up and releases water vapor and other gases.

  • These gases can cause the magma in the mantle to rise up and erupt through the Earth's Crust. This is how volcanoes are formed at Subduction Zones.

  • Volcanoes can be very dangerous. When they erupt, they can spew out lava, ash, and gases that can destroy homes, businesses, and infrastructure.

  • They can also cause tsunamis and earthquakes. However, volcanoes also play an important role in the Earth's climate. They release gases into the atmosphere that help to regulate the Earth's temperature. They also create new land by spewing out lava and ash.

Types of Volcanoes :


  1. CINDER CONES :

  • Cinder Cones are small, steep volcanoes that are typically built up from fragments of lava that solidify in mid-air. They are formed by relatively short, explosive eruptions. Cinder cones are some of the simplest volcanoes and can erupt frequently. They typically only reach a few hundred feet in height.

    2. COMPOSITE VOLCANOES :

  • Composite Volcanoes (stratovolcanoes) are large, symmetrical volcanoes that are built up from alternating layers of lava, ash, and rock. They are formed by a long history of eruptions, which can include both explosive and effusive eruptions. Composite volcanoes can be some of the most dangerous volcanoes because they can erupt violently and produce large ash clouds. Some well known examples of composite volcanoes include Mount Fuji in Japan and Mount Rainier in Washington State.

    3. LAVA DOMES :

  • Lava Domes are small, steep-sided volcanoes that are formed by the slow extrusion of viscous lava. Lava domes can be dangerous because they can collapse, generating lahars, which are mudflows of volcanic debris.

    4. SHIELD VOLCANOES :

  • Shield Volcanoes are broad, gently sloping volcanoes that are formed by the eruption of fluid lava. Shield volcanoes are the largest volcanoes on Earth. The largest volcano on Earth, Mauna Loa in Hawaii, is a shield volcano.