Volcanoes are often cone-shaped, but they can take other shapes too.
The melted rock that spills out of the crater on the top of the volcano is called lava . The lava destroys everything in its path because it is very, very hot! A volcano erupts when magma and gases find a way to escape, so they burst to the surface through a vent . An eruption can be quite gentle or very violent. Why does a volcano erupt?
Where do volcanoes happen? Most volcanoes are formed on land, but there are some volcanoes that are on the ocean floor. Some of these volcanoes emerge from the water because they are very high. Map 1. The world patterns of volcanoes and earthquakes South America North America Asia Australasia Europe Africa
This is the fiercest eruption of all because the gases and magma become trapped inside the volcano. This causes a huge explosion, which can be big enough to remove the top of the whole mountain!
Composite Cone The volcano is built up of alternate layers of LAVA and ASH. They can explode with great violence. Mt St Helens - USA Conelet Dyke Crater Ash layer Lava Layer Flank eruption Lava Flow Crust Pyroclastic Flow
Shield ( Basic) Cone Shield Volcanoes are enormous features built up only from layers of lava. They produce lots of lava but they tend not to erupt violently. Mauna Loa Hawaii -USA 250 miles 10,000m Composite volcano to scale Layers of Lava Lava Flow
Ash and Cinder Cone Paracutin - Mexico Layers of Ash and Cinder Volcanic Bombs Pipe The volcano is built up of layers of ASH. When it erupts it is normally with great explosive force. 3,000m