Photographies de volcans
A volcano is a mountain or hill formed by lava and volcanic ash that has accumulated through eruptions. Volcanoes are formed when magma rises to the surface of the Earth through faults or violent eruptions. Magma is molten rock found in the deepest layers of the Earth. When it reaches the surface, it can form molten lava that flows to the ground, or it can explode and create volcanic ash and gas. Volcanoes can be active, dormant or extinct, depending on how often they erupt. They can also be classified into different types according to their shape and structure.