A volcano essay

Solo disponible en BuenasTareas
  • Páginas : 4 (834 palabras )
  • Descarga(s) : 0
  • Publicado : 23 de octubre de 2010
Leer documento completo
Vista previa del texto
Volcanoes and their characteristics.

Volcanoes are one of the most fascinating geological land forms in our natural environment. A volcano or “Vulcan” (Greek name), can be defined as an opening,or rupture, in a planet's surface or crust, which can be classified by different characteristic such us; volcanic activities, different volcanic features, amongst other. Another characteristic isthat we can find them, in the earth as well as in other planets.

Volcanoes according to their volcanic activity can be classified in: active, extinct and dormant. A popular way of classifyingmagmatic volcanoes is by their frequency of eruption, with those that erupt regularly called active. Scientists usually consider a volcano to be erupting or likely to erupt if it is currently erupting, orshowing signs of unrest such as unusual earthquake activity or significant new gas emissions, most scientists consider a volcano active if it has erupted in Holocene times. Historic times are anothertime-frame for active, instead extinct volcanoes, are those that scientists consider unlikely to erupt again because the volcano no longer has a lava supply, for example, the Yellowstone Caldera inYellowstone National Park is at least 2 million years old and hasn't erupted violently for approximately 640,000 years, so it is difficult to distinguish an extinct volcano from a dormant one. Volcanoesare often considered extinct if there are no written records of its activity. Nevertheless volcanoes may remain dormant for a long period of time, and it is not uncommon for a so-called "extinct"volcano to erupt again. Vesuvius was thought to be extinct before its famous eruption, which destroyed the towns of Herculaneum and Pompeii.
The structure and behavior of volcanoes depends on a number offactors. Some volcanoes have rugged peaks formed by lava domes, also exist stratovolcanoes and submarine volcanoes. Lava domes are built by slow eruptions of highly viscous lavas, they are sometimes...
tracking img