Volcanoes

The word volcano comes from the name of the island on the Mediterranean Sea. Mainly the volcanoes are formed by destructive and constructive margins.

A volcano can erupt many times during its lifetime of thousands of years. Material which is expelled during the eruption step by step builds up a volcano. The throat of the volcano is called the main vent; usually there is a crater at the top of the Main Vent. Volcanic eruptions can be described as explosive or quiet. When the magma is sticky and contains lots of gas than eruptions are likely to be explosive. Hot pieces, called pyroclastics are being thrown out during violent explosions. Heavier peaces land near the crater and start to build the cone shaped mountain, lighter peaces can be carried by wind hundred of kilometers away. If the magma is fluid and contains less gas it is when eruptions are quiet. Melted rock called lava runns out of the volcano and cools up on its slope. Non-constant eruptions of pyroclastics materials and lava build the mountain layer by layer. Three different types of materials may be expelled from an active volcano. These materials are lava, rocks (Volcanic bombs, lapilli, cinder, ash, dust) and gases. There are three types of volcanoes: Shield, Cinder and Composite volcano.

There are some advantages and disadvantages of volcanoes. The advantages are that volcanoes create National Parks, they give inspiration to people, create volcanic soils which are rich in minerals and good for making crops. Also the advantage is the Cooling Effect which is made by the eruptions of volcanoes. There are also disadvantages of volcanoes the main one is that they cause damage and kill people while they erupt.