Volcanoes and safety precautions must be taken at the occurrence of volcanoes
The volcano is an opening in the Earth’s crust that permits the passage of trapped gases and molten materials (lava).
The causes of the volcano occurrence:
|lava flows cover and destruct whole towns and villages|
The direct cause of the volcano occurrence is the presence of weak parts in the Earth’s crust, where molten materials are going out to the Earth’s surface.
Parts of the volcano:
It consists of three parts which are:
- The volcanic vent: It is an opening lies at the top of the volcano.
- The volcanic pipe (or neck) which is a cylindrical cavity that connects the Earth’s interior with the surface, through which the magma moves during its ascendence.
- Volcano cone which is the body of the volcano. It consists of molten materials after their solidification and accumulation around the volcanic vent.
The products of the volcano:
The materials ejected during the volcanic eruption are fragmented materials, lava and volcanic gases.
The fragmented materials are materials that the volcano emanates. These materials are different in size ranging from big projectiles to volcanic ashes.
Lava (or lava flows) which are molten material mass that spreads on the volcanic sides.
The volcanic gases which are the fused (mixed) gases with the magma and the most important of them are water vapour and oxides of carbon, nitrogen and sulphur.
Harms of volcanoes:
The Lava and the lava flows cover and destruct whole towns and villages.
Spreading of poisonous gases and volcanic dust into far places and they cover large areas.
The fire catches in the forests and neighbouring places to the volcano and causes a lot of damage.
The volcanoes destroy the cultivated lands near it.
The benefits of volcanoes:
In some countries, the thermal energy resulted from the volcano is used to produce electricity.
- The volcanic projectiles and ashes form more fertile soil, So, the most important crops are produced.
- They form new islands in the seas and increase the area of land.
- Volcanic rocks are produced by volcanoes, and they have great economic values.
Safety and security precautions that must be taken at the occurrence of volcanoes:
During the volcanoes, we must evaluate the people from the neighbouring areas of the volcano as soon as possible.
To avoid the poisonous gases emanated from the volcanoes, people must take account of the instructions of forecasting of the wind direction.
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