3. Volcanoes

The word volcano is derived from the name of ‘Vulcano’, a volcanic island in the Aeolian Islands of Italy whose name in turn originates from ‘Vulcan’, the name of a god of fire in Roman mythology.

Volcano is a vent or an opening through which heated materials consisting of water, gases, liquid lava and rock fragments are erupted from the highly heated interior to the surface of the Earth. The layer below the solid crust of earth is mantle. It has higher density than that of the crust. The mantle contains a weaker zone called asthenosphere. 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. Once it starts moving towards the crust or it reaches the surface, it is referred to as lava.

‘Volcanology’ or ‘vulcanology’ is the term given to the study of volcanoes, and the scientists who study them are called the ‘volcanologists’ or ‘vulcanologists’.