Volcanoes

  • A volcano is an opening which throws out magma from form within the Earth to the Earth’s surface.
  • Magma coming out from a volcano is referred to as lava .
  • A volcano can be active if it is in the stage of erupting lava.
  • A volcano is called a dormant volcano in case it has not erupted in a very long time.
  • When this dormant volcano does not erupt for thousands of years, it is termed as an extinct volcano.
  • Depending upon the explosive nature of the volcano, different land forms can be formed such as a plateau (if the residue spreads, which means the volcano is not explosive in nature) or a mountain ( if it explodes, which means the volcano is explosive in nature)

Three common volcanoes are:

Shield volcano

They are formed by running lava and spread to a larger space. The magma coming out is known as basaltic magma.

Composite volcano

  • They are also called strato-volcanoes.
  • They are explosive in nature
  • The magma is known as andesitic magma.

Caldera volcano

It is hugely explosive in nature which makes the volcano collapse and results in a depression on the surface.

THE REASON FOR VOLCANOES

The reason for volcanic activity is the movement of techtonic plates.

DIFFERENCE BETWEEN MAGMA AND LAVA

Magma is liquid rock inside a volcano. Lava is liquid rock (magma) that flows out of a volcano.

LAVA COOLS SLOWLY BECAUSE….

Lava is a poor conductor of heat. Lava flows slow down and thicken as they harden.

What is the Ring of Fire?

The Pacific Ring of Fire is an area of frequent earthquakes and volcanic eruptions in the  Pacific Ocean. It has over 50% of the world’s active and dormant volcanoes.

MUST KNOW TERMS

ACTIVE VOLCANO – An active volcano is one that erupts regularly.

DORMANT VOLCANO – A dormant volcano is one that has not erupted for many years, as explained above.

EXTINCT VOLCANO – An extinct volcano is a volcano which is not active at all.

GEYSERS – Caused by the heat trapped inside the earth which causes the heating of ground water. They come out from the surface at certain places as springs in the air.

ASH – Small particles of lava after being thrown up outside the Earth through the vent in the volcano

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