Question

How are volcanos formed? What are the advantages and disadvantages of it?

Answer 1

Volcanoes are formed when magma from within the Earth's upper mantle works its way to the surface. At the surface, it erupts to form lava flows and ash deposits. Over time as the volcanocontinues to erupt, it will get bigger and bigger.

Answer 2

The obvious disadvantage is the hazard posed by volcanic eruptions- Pompeii is an example of a volcanic disaster.

Advantages- gases escaping from volcanoes formed the atmosphere.  Volcanic soils are rich in nutrients which is important for agriculture.  Most metallic mineral deposits form from hydrothermal (hot water) activity near volcano.