Monday, 1 March 2010
The definition of the volcano:-Is that place from which he graduated or emits materials Alzirip warm with fumes and gases associated with the depth of the earth's crust and occurs during the nozzles or cracks. And accumulate molten material or by type of flow to form the different land forms, including conical hills or high volcanic mountains.
Volcanoes of the unique natural phenomena called the attention of rights since the League and they play a great role in geological processes that affect the evolutionary history of the earth's crust and shape. This is because most parts of the earth's crust affected Alandfaip underwent operations in its composition to the contribution of operations Alandfaip. According to a study to identify the volcanic centers of study of earthquakes and volcanoes, a branch of geology, which has become known as a stand-alone volcanology.
Parts of volcanoes:-
1-Cone-shaped mountain: composed of the wreckage of a rocky material thrown from the volcano crater was all or some of them in molten state.
2-Mouth: It is a cavity almost round shape at the top of the cone, width ranging from a few thousand meters. And flowed from the crater at intervals of gas and the masses of rock, shells and lava and molten materials.
3-Chimney or reed: a channel extending from the bottom of the crater to the bottom where you connect a bakery magma underground. And push through volcanic material to the crater. Sometimes known as the neck of the volcano.
Types of volcanic materials:-
1-Rocky debris: emerge as a result of volcanic eruptions rocky debris into different types and sizes usually in the first period of volcanic eruptions.
2-Gases: Graduated from volcanic activity during the gas water vapor, which derives a great quantities of a component of the huge clouds mixed with dust and other gases. Is building these fumes, causing the heavy rain falling in the vicinity of the volcano.
3-Lava: The liquid clusters "instead of volcanoes, and has a temperature between 1000 and 1200, the two types: -
*LAVA lightweight, light colored.
*LAVA heavy dark color.
Forms of volcanoes:-
1- Volcanic rock debris:
Vary in shape depending on the volcanic cone material that consists of them. If the cone composed entirely of rock debris, we found a high steep for the space occupied by the base.
Arise as a result of exit and lava accumulation around the main crater and look like low-rise for the large area occupied by the rules. The peaks seem like Bhiab convex.
Stratified volcanic common type of existence, is in the form of ex-center types and composed of materials Mkrotadtha debris flows, lava rock and directed by the volcano eruption, while ease.
The geographical distribution of volcanoes:-
1-omain that surrounds the Pacific Ocean and coastline, which is sometimes known as Ring of Fire.
2-There are many volcanoes in the Pacific Ocean itself and some great grew up in a huge hall and appeared towering above the level of its waters. Volcanoes, including the Hawaiian Islands, which is based norms in the ocean at a depth of 5000 m, and rises above the water surface of more than 4000 m.
3-Southern Europe, overlooking the Mediterranean and the adjacent islands. The most active volcanoes here Vesuvius near Naples, Italy, and Sicily, and Aetna Islands Astro Mpule (Lighthouse of the Mediterranean) in the islands of Lipari.
4-Highlands of Western Asia and months and Ararat volcanoes Aliuzenz.
5- Scale-east of Africa and months Brkinh Kilimanjaro. Me.
Effects of volcanoes:-
1-In the formation of the Earth's surface:
Above that we can discern the effects of volcanoes in the formation of the Earth's surface is created majestic mountains and plateaus spacious. When subside arise in the cavities of lakes in those pores rainforest.
2-In human activity:
Strange that a man did not played accommodation near volcanoes in order to be safe from the dangers, seen live near them, but on the slopes as well. Vesuvius volcano, surrounded by villages and towns and covered with fruit groves, vineyards and orchards spread over all of its aspects until near the top. The Agriculture also on the slopes of a volcano (Athina) in the island of Sicily in 1200 to a height in the fertile soil is composed of black basalt that spilled over the region during the historical periods.
The famous island of Java volcanoes rebellious and active volcanoes than virtually every volcano in the world in the amount of spills and Alloafez that flowed from them since 1500, however, we find the island full of population, it is the densest points of the world's agricultural population to the area and home to about 75 million people due to fertility as we have already volcanic soil, was established by the Department of Volcanology and function to predict volcanic eruptions and warn the population before the volcanic eruptions, which reduces the risk of their occurrence.