Volcanoes
What is a volcano?
Volcanoes are openings in the Earth’s crust through which molten lava, red-hot rocks, steam and fumes pour out. We usually think of a volcano as a smoking mountain that erupts explosively, but most volcanoes are simply cracks in the crust through which lava flows continuously.
The more familiar kind of volcano has a single central pipe though which lava reaches the surface, building up into a cone as it cools. The cone consists of layers of lava and volcanic ash. There is usually a crater at the centre. Most active volcanoes smoke and spit out occasional pieces of lava, and dramatic eruptions are rare.
Picture credit: google
How fast do volcanoes grow?
Unlike most geological happenings, the growth of a volcano can be very rapid. In 1943, a farmer in Mexico noticed smoke coming from a crack in the ground in his cornfield. Lava began to ooze out, and six days later it had piled up into a volcanic cone 150 m high. By the end of the year the cone had grown to 450 m. The eruption finally stopped in 1952, when the volcano Paricutin had reached a height of 2,808 m above sea level. The volcano had buried two whole villages.
Picture credit: google
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