A volcano is simply a mountain created when material from inside the Earth escapes to the surface, on account of high pressure and intense heat. It is a vent or a chimney which transfers molten rock, magma, from depth to the Earth's surface.
The word volcano is derived from the name of a volcanic island in the Aeolian Islands of Italy, Vulcano. The island’s name in turn originates from ‘Vulcan’, the name of a god of fire in Roman mythology.
What is lava?
Lava is the material which comes out of a volcano and solidifies around it. Molten Lava is known as magma.
How are volcanoes different from mountains?
Most mountains in the world are formed from collision of continental plates, their upliftment and erosion. On the other hand, volcanoes are created when material from inside the Earth escapes to the surface and settles down. Volcanoes can be formed under water as well.
How are volcanoes formed?
Volcanoes are formed by magma, which flows from within the Earth's upper mantle to the surface. Volcanoes erupts at the surface to form lava flows and ash deposits. It becomes bigger over time as it continues to erupt.
Why do volcanoes erupt?
When gaseous pressure within the Earth’s surface reaches a saturation point, it erupts in the form of volcanic eruption. The Earth's crust is made up of huge tectonic plates, which are put together like a jigsaw puzzle. These plates sometimes tend to move and their friction leads to the opening of a volcano.
What is an Active Volcano?
To connect the activity of a volcano with time span has been a contentious issue and the dispute remains unresolved. According to a particular school of thought, an active volcano shows some periodicity and must have had at least one eruption during the past 10,000 years. An active volcano could be erupting or dormant. A dormant one is an active volcano which has not erupted for years but is supposed to erupt again. Once a volcano has been dormant for more than 10,000 years, it becomes extinct.
Volcanic hazards
Volcanic eruptions generally have hazardous consequences and can cause lateral blasts, lava flows, hot ash flows, mudslides, avalanches, falling ash and floods. In the past, volcanic eruptions have also knocked down entire forests. An erupting volcano can trigger tsunamis, flash floods, earthquakes, mudflows and rockfalls.
An Interesting fact
Volcanic ash clouds have the potential to damage aircraft engines. Unfortunately, ash is not visible by radar, which is the main navigation aid for aircraft. Nine Volcanic Ash Advisory Centres around the world use satellites to help track volcanic ash clouds and provide warnings for aircraft.