User:Damonians

volcanoes

A volcano is a opening in the earth’s crust through which molten material erupts suddenly. Volcano is the eruption of pressure build by magma and gases inside the earth. There are many effects caused by volcano, like, Tsunami(Under ocean), Mixing of poisonous gases in air, Forest Fire and loss of property and life.

A Volcano erupts due to plate movements inside the earth, this process may be studied under Plate tectonics.

Stages of volcanoes includes - Active, Dormant, and Extinct. An active volcano is the recently erupted and may erupt again soon. A Dormant volcano is the volcano which is not erupted for long time period and it may erupt in the future. And a Extinct volcano is the volcano which has not erupted for so long time and no longer erupts in the future. There are Four types of Volcanoes - i) Cinder Cones - Cinder cones are circular or oval cones made up of small fragments of lava from a single vent that have been blown into the air, cooled   and fallen around the vent.  ii) Composite Volcanoes - Composite volcanoes are steep-sided volcanoes composed of many layers of volcanic rocks, usually made from high-viscosity lava, ash and rock debris iii) Shield Volcanoes - Shield volcanoes are volcanoes shaped like a bowl or shield in the middle with long gentle slopes made by basaltic lava flows. iv) Lava Volcanoes - Lava domes are formed when erupting lava is too thick to flow and makes a steep-sided mound as the lava piles up near the volcanic vent.