Question

How is a volcano formed? Mention any three significance of volcanoes.

Answer 1

Explanation:

Volcanoes are formed by eruptions of lava and ash when magma rises through cracks or weak-spots in the Earth's crust. A build up of pressure in the earth is released, by things such as a plate movement which forces molten rock to exploded into the air causing a volcanic eruption....

Answer 2

A volcano is an opening in the earth's crust through which lava, volcanic ash, and gases escape. ... Beneath a volcano, liquid magma containing dissolved gases rises through cracks in the Earth's crust. As the magma rises, pressure decreases, allowing the gases to form bubbles.