A Volcano is an opening in the Earths crust through which volcanic ash, lava, and gases escape. Some volcanic eruptions are explosive and others are not. The explosivity depends on the composition of the magma. Explosive volcanic eruptions can be dangerous and deadly. The ash erupted can suffocate plants, animals and humans.
Candidates would find this topic to be of importance while preparing for IAS Exam.
How do Volcanoes Occur?
Deep inside the earth because of the prevalent high-temperature rocks melt slowly and becomes a thick liquid substance called magma. Since the liquid magma is lighter than surrounding solid rock, it starts rising up and collects in the magma chamber. Eventually, due to pressure build-up, magma comes out of the openings on the earth surface. Magma which flows out of these openings is called lava.
What are the 3 types of Volcanoes?
There are 3 main types of volcanoes.
- Composite or Strato – These volcanoes rise over 8000 feet. Lava can travel down the side of a volcano in very high speeds with temperatures ranging over 400-degree celsius. These kind of volcanoes are a threat to nearby life and property.
- Shield – Eruptions are non-explosive, the flow of lava is very fast. Eruptions occur frequently. They destroy property but death or injury to humans is rare.
- Dome – The lava that flows out is thick and sticky, hence it does not travel far.
What is the Most Dangerous Volcano in the World?
As per experts, Mount Vesuvius volcano in Itlay is the most dangerous volcano in the world. As per the United States Geological Survey (USGS), there are approximately 1500 active volcanoes in the world. Among those only 500 have erupted in modern history and only some of these 500 volcanoes can cause devastating damage.
The above details would help candidates preparing for UPSC 2020.