Volcanoes Risks and Benefits

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  • Topic: Volcano, Lava, Volcanology
  • Pages : 10 (3287 words )
  • Download(s) : 412
  • Published : January 8, 2011
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I. Introduction…………………………… 1
II. Body…………………………… 2
a. Definition…………………………… 2
b. Kinds of volcano…………………………… 2 c. Types of eruption…………………………… 3 d. Risk…………………………… 4
e. Benefits…………………………… 11
a. Tourism…………………………… 11
b. Environment…………………………… 13
III. Conclusion…………………………… 15 IV. Bibliography…………………………… 17

Introduction
The term volcano can either mean the vent from which magma erupts to the surface, or it can refer to the landform created by the solidified lava and fragmental volcanic debris that accumulate near the vent. One could say, for example, that large lava flows are erupted from Kilauea volcano in Hawaii, the world volcano here signifies a vent.

Volcanoes are not the realm of any single scientific discipline. Rather they require study from many scientists from several specialties: Geophysicist and Geochemist to probe the deep roots of volcano; Geologist to decipher prehistoric volcanic activity; Biologist to learn how life became established and evolve in barren volcanic islands; and meteorologist to determine the effects of volcanic dust and gases on the atmosphere, weather and climate.

Volcanoes affect humankind in many ways. Their destructiveness is awesome, but risk involved can be reduced by assessing volcanic hazards and forecasting volcanic eruptions.

Body
Volcanoes Risks and benefits
Definition
First of all, we should know what a volcano is.
Volcano is an opening in the earth’s surface. Through this opening has come rock so hot that it is in a liquid or gaseous state. This melted rock deep in the earth is called magma. Philosophers once thought that volcanic eruptions came from the burning of natural fuels. Sir Charles Lyell and his associates later showed the volcanic mountains were piled up from the products of their own eruptions For hundreds of years, volcanoes have struck terror and wonder into the heart of man. In ancient time, they even moved man into worship. The word volcano comes from Volcanus, the name of the Roman god of fire. The name was first used for volcano, one of the Lipari Islands in the Mediterranean Sea where the god was thought to live. Kinds of Volcano

Volcanoes are commonly classified as active, dormant and extinct. The distinction between the categories is not very clear and consequently any classification based on this criterion and is highly arbitrary. The separation of dormant and extinct volcanoes is particularly difficult. A volcano may lie quiet many hundreds of years and then awaken, often violently.

Some volcanoes are constantly active . Izalco in El Salvador, and Stromboli in the Mediterranean Sea, erupt so regularly that they have been compared to light houses. Those that are quiet, but have not been dead for us to know when they will break out again are called dormant volcanoes. Volcanoes that have been remained quiet since the beginning of recorded history and probably will not erupt are called extinct volcanoes. Other volcanoes can be called intermittent because, they erupt fairly at regular periods. Many of these erupt in cycles, with the length of cycle being fixed by the amount of time needed to make enough heat to produce eruption. Types of eruption

In classification schemes based on character of eruption, volcanic activity and volcanic areas are commonly divided into six major order of increasing degree of explosiveness: (1) Icelandic, (2) Hawaiian, (3) Strombolian, (4) Vucanian, (5) Pelean and (6) Plinian. The Icelandic type of eruption is characterized by effusion of basaltic lave that flow from long parallel fissures. Such outpouring build lave patterns. The least violent type of eruption is termed Hawaiian and is characterized by extensive lava flows from central vents or fissures and occasionally accompanied by lava fountains. Strombolian eruption is characterized by moderately fluid lava flows, usually accompanied by violent...
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