A volcano is an opening on the surface of the earth. Mostly in the form of a high mountains / hills. These arise over time through many volcano eruptions where lava exits the volcano and cools down. The name “Volcano” comes from the island Sicily in Italy. On this island happen a lot of volcano eruption so the population living there gave the island the name volcano, because of the fire god “Vulcanus”.
Long time ago no one knew why volcanoes originated only in certain places and at others not at all. In the year 1912 a German scientist named Alfred Wegener developed a theory that later became true. His theory said that the earth crust is not one complete piece, but consist of several continental plates. These plates are not fixed anchored but are moving every year a few centimetres. This process of the moving plates is called plate tectonics. At these areas where the earth plates drift apart (convergent plate boundary), collide (convergent boundary) or drift past each other (conservative plate boundary) arise volcanoes.
HOW DO VOLCANOES FORM?
So if these movements cause cracks or rifts, it can happen that liquid magma is thrown out. When it reaches the earth surface gases escape and it becomes lava. The temperature is about 500° to 1200° when it gets thrown out. After that it cools down. Through this cooling process huge hills are formed which we all know as volcanoes.
Structure of a volcanoDeep down every volcano has a magma chamber. In this magma chamber fills up with liquid fused rock and volcanic gases. As soon as the magma chamber is filled up, the magma makes its way through the volcano vent to the earth`s surface. The end of the volcano vent is called crater. There are a few different craters.
Here are the most active volcanoes around the globe.