How are volcanoes useful to mankind?

Hot molten rock comes out from the crack of the outer layer; from this molten rock material volcanoes are formed. Even though volcanic eruptions are dangerous to mankind but they are also useful in many ways –

• From the weathering of the lava rocks, the soil is formed which is fertile in nature. For example- the black soil of the Deccan plateau.

• In volcanic regions, Geysers are formed. Geysers are the hot spring of water which comes out and also throws steam into the air along with this, example - The Old Faithful Geyser, Yellow Stone National Park and North America.

• Volcanic ash is good manure.