What is a Volcano?
This film, from Twig World, looks at the cycle of lava as a destructive and constructive force, building the structure of volcanoes and powering their devastating impact. The key points made in the film are: •Volcanoes are landforms that occur along plate boundaries. •Volcanoes consist of a magma chamber, main and secondary vents and a crater. •Volcanic eruptions occur when pressure forces magma from the chamber to the main vent. •The pressure forces the crater to blow and release molten rock, ash and a cocktail of gases into the atmosphere.