Volcano

Fire-blowing natural dragons

Volcano is basically an opening of the Earth’s surface which erupts magma (present inside the Earth) onto the surface of the Earth. Earth surface is basically divided into many tectonic plates. These tectonic plates are present just below the crust of the Earth. Volcanoes are generally found or are formed in places where these tectonic plates converge or diverge.

Study of volcanoes is called Volcanology.

The phenomenon of magma eruption is called Volcanism.

What makes magma to flow outward from a volcano?

The main player here is buoyancy. Magma is extremely hot, and thus less dense than the surrounding rocks and material. Because of this magma rises above due to difference in buoyancy. But as magma reaches another fascinating thing happens.

If the magma contains elements like water or gases like carbon dioxide, methane etc., as it reaches the surface, these elements suddenly expand into streams and plumes of gas which causes explosive eruptions or raging intense violent eruptions. Explosive eruptions happens when the magma is more acidic in nature. More basic magma leads to effusive eruptions in nature and have steady and gentle outward flow of lava.

Types of volcanoes

Composite Volcano

Also known as Startovolcano. Starta means layers of rocks or rock like material. It is most common type of volcano.

They are steep sided volcanoes. Steep sided volcanos are made from flowing lava on the sides and the ash when it rests on the volcanic eruption. These volcanoes can have pyroclastic lava flow. A pyroclastic flow is a flow of semi-liquid material which is a mixture of lava, ash, rocks and dust.

Volcanic Eruptions of these kinds of volcanoes produce very thick and highly viscous lava. Highly thick lava takes time to flow down and hence lava starts to cool and solidify around the volcano’s top only. It can’t travel far down the slope with that viscosity.

Shield Volcanoes

Volcanoes with gentle slopes are called shield volcano. They don’t have steep sides rather are they look like a flatten bed of solidified lava.

Eruptions of shield volcano are non-explosive (effusive eruptions) and more frequent. Shield volcanoes produce low viscous lava and hence it flows longer distances.

Cinder Cone Volcano

A steep cone-shaped volcano which is formed tephra or volcanic debris that accumulates over time around the sides of the volcano.

Acid lava Volcanoes