What volcanoes ?
Sunday, March 31
What volcanoes ?
The volcanoes of the unique natural phenomena that drew the attention of the man since ancient times and they play a great role in the geological processes that affect the evolution of the earth's crust and posed. This is because most of the affected parts of the earth's crust impulsivity and underwent operations in composition to the contribution of operations impulsivity.According to a study volcanoes to identify the centers of earthquakes and study volcanoes branch of geology, which became freestanding known as volcanoes. The volcanoes associated metals and ores are very important economically.
Definition the volcano:
The volcano is that place, who graduated or emits materials warm Alziria with fumes and gases accompanying the depth of the earth's crust and occurs through nozzles or cracks. And accumulate magma or glides by type to form a different land forms, including conical hills or high volcanic mountains.
Penalty volcanoes:
If you look at the form you'll find that it consists of:
1 - conical Mount:
Composed of rocky debris or hardened lava. It volcanic material thrown from the crater and was wholly or partly in the molten state.
2 - nozzle: It is almost round in shape cavity at the top of the cone, the wider ranges from a few thousand meters. And derive from the gas nozzle at intervals and stone blocks and mortar and lava and molten materials (LAVA) volcano may have more than one nozzle secondary to the main crater at the top as you can see in the figure:
3 - chimney or rod: a channel that extends from the bottom of the crater to the bottom where relate oven magma in underground. And hurtling through volcanic material to the nozzle. Known sometimes neck volcano.
And next to the main chimney, the volcano may be several chimneys related secondary Balfohat.
Types of volcanic material:
Comes out of volcanoes while eruption rocky debris solid and liquid materials.
1 - rock debris:
Emerges as a result of volcanic eruptions rocky debris into various types and sizes usually in the first period of volcanic eruptions. And rock debris derived from the rigid crust extracted from the walls of the neck as a result of payment of lava and gaseous materials emanating from the magma force and violence and composed rock debris of materials vary in size rock masses, shells and pebbles, sand and volcanic dust.
2 - GAS:
He graduated from volcanoes during its gas water vapor, which pops up in great quantities configured to huge clouds mixed with dust and other gases. And condense these vapors causing heavy rain falling in the vicinity of the volcano. And accompanied by explosions and rainfall of electric lights arise from friction volcanic ash particles to each other and as a result of air turbulence, and except for water vapor severe heat, multiple volcano spews gas mainly hydrogen and chlorine, sulfur, nitrogen, carbon, and oxygen.
3 - lava:
Are liquid throw it blocks volcanoes, and has a temperature of between 1000 m and 1200 m. Lava flows from the crater, as bursting through the cracks and fractures in the volcanic cone aspects, those fractures created by the explosions and blocks magma pressure, and stop nature of lava and appearance on the chemical composition of magma blocks which emits They are of two types:
A - LAVA light-colored light:
This is characterized by bone viscosity, and thus slow the flow and like lava that emanated from the volcano Bailey (Islands Almrtnik in the Caribbean) in 1902 was a dense, sticky to the point that it overwhelmed the move, and took accumulate and rise consisting of Tower above the crater reached a height of about 300 m , and soon after that break and crash as a result of the explosions caused by the exit gases.
B - LAVA heavy dark:
It LAVA basaltic, and the advantage of being liquid and moving to a large degree, and flows in the form of streams on the slopes of the volcano, and when it emerges lava through fractures great extension they are spread out over large areas composed of plateaus spacious, like the Ethiopian highlands and the Deccan Plateau, India and the Golan Colombia North America.
Forms volcanoes:
1 - rock debris volcanoes:
The shape of volcanic cone in different materials from which they are composed. If the cone is made up entirely of rock debris, we found high steep for the area occupied by the base. Here we find the gradient of 30 degrees was sometimes up to 40 degrees Celsius and These forms usually arise as a result of volcanic eruptions. The Islands of Indonesia.
2 - Plateau volcanoes:
And arise as a result of exit and accumulation of lava on the main nozzle and low-rise look for large area occupied by the rules. And looks peaks like Bhiab convex hence renamed volcanoes plateau has originated cones of flow Mushorat lava severe heat and great liquidity, which spread over large areas and are these volcanoes Plateau best representation in the volcanoes of the Hawaiian islands Like a volcano Monalo with a height of 4100 m and it seems like a spacious dome descend steeper easy Hina.
3 - Layering volcanoes:
Layering is a common type volcanoes exist, which is in the shape ex-center types and consist Mkhrotadtha of rock debris material and lava flows directed by the volcano while restless eruption.
And be Alloafez that comes out of the volcano during eruptions successive layers on top of one another, and section consisting of coarse material and another section of the materials minutes, and between this and that interfere in the form of lava thin strips. From this arises a kind of stratigraphy in the installation of the cone and this figure represents the Mayon volcano more Philippines active volcanoes in the present time.
Geographical distribution of volcanoes:
Spread over long ranges volcanoes on Earth shown:
1 - range that surrounds coasts Pacific, which is sometimes known as Ring of Fire, it runs on the eastern shores of the ocean above the heights of the Andes to Central America and Mexico, and above the heights west of North America to the Aleutian Islands and then to the coast of East Asia to the islands of Japan, the Philippines and then to Islands of Indonesia and New Zealand.
2 - There are a lot of volcanoes in the Pacific Ocean itself and some huge great grew up in the hall and appeared towering above the water level. And volcanoes of the Hawaiian Islands, which is based bases in the ocean at a depth of about 5,000 m, and rises above the surface of the water more than 4,000 m, bringing the total height from the bottom of the ocean to the peaks of about 9,000 m
3 - Southern Europe on the Mediterranean seafront and its adjacent islands. The most famous active volcanoes here Vesuvius near Naples, Italy, and Aetna islands of Sicily and Astro Mpule (beacon Mediterranean) in the Lipari Islands.
4 - Heights West Asia and months volcanoes Ararat and Alauzenz.
5 - range east of Africa and months Kilimanjaro Brkinh.
Effects of volcanoes:
1 - in the formation of the Earth's surface:
We can thus advances to discern the effects of volcanoes in the formation of the Earth's surface they arise majestic mountains and plateaus spacious. When subsided arise in their pores Lakes cavities in the rain bodies.
2 - in human activity:
Strange that man was playing the housing next to volcanoes in order to be safe from the dangers, as we find live near them, and even on the slopes. Fberkan Vesuvius is surrounded by villages and towns and covered with gardens and fruit groves and vineyards and all spread over aspects even near the top. Agriculture is also on the slopes of a volcano (twelve) on the island of Sicily to a height of 1200 m in the fertile soil is composed of black basalt flow over the area during historical times.
These volcanoes unforgiving as arise from time to time destroying one village or another can rest along the main road on the lower slopes of the volcano twelve and at the end of flowing lava flows which eternal evidence has permanent danger posed to the region.
The famous island of Java Berakinh rebellious and active volcanoes than actually all volcanoes world in the amount of spills and Alloafez that emerged of them since 1500 AD, however, we find the island filled populated, they are denser parts of the world agricultural population for an area inhabited by about 75 million people and is due as we have said to fertility volcanic soil, has been established by the Department of volcanoes and function predict volcanic eruptions and warn people before volcanic eruptions which reduces the risk of occurrence.
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