Volcanoes Facts for Kids
Explosive facts about volcanoes and geology
Volcanic islands often develop unique species found nowhere else on Earth because their isolation means plants and animals evolve independently over millions of years. The GalΓ‘pagos Islands, formed by volcanic activity, are famous for the unique wildlife that inspired Charles Darwin's theory of evolution.
Flood basalts are the result of enormous outpourings of lava that covered vast areas of land millions of years ago, producing flat plains of dark basalt rock. The Siberian Traps and the Deccan Traps are examples of ancient flood basalt provinces that covered areas the size of continents.
A crater is the bowl-shaped depression at the top of a volcano's vent, usually up to a kilometre across, while a caldera is a much larger depression formed by the collapse of the volcano itself after a massive eruption. The caldera of Toba in Indonesia is about 100 kilometres long.
The Earth's mantle, which lies beneath the crust, is made of hot solid rock that flows very slowly over millions of years β it is not a sea of liquid magma. Magma only forms in specific conditions, such as where pressure drops or where water lowers the melting point of rock.
When volcanoes erupt beneath ice sheets or glaciers, the heat melts the ice and can trigger catastrophic floods called jΓΆkulhlaups. Iceland regularly experiences these dramatic glacial outburst floods from eruptions beneath its vast ice caps.
During some eruptions, lava can be blasted high into the air in spectacular fountains reaching hundreds of metres tall. Lava fountains happen when magma rising rapidly releases dissolved gas, propelling molten rock skyward like a fizzy drink being shaken.
Whakaari (White Island) in New Zealand is the country's most active volcano, rising from the ocean off the Bay of Plenty coast. It was a popular tourist destination until a deadly eruption in December 2019 reminded the world how unpredictable volcanoes can be.
Modern volcano monitoring stations use gas sensors to measure changes in the amounts of sulphur dioxide, carbon dioxide, and other gases being released by a volcano. A sudden increase in certain gases can be an important warning sign that an eruption is approaching.
Around 800 million people worldwide live within 100 kilometres of an active volcano, attracted by fertile soils, geothermal resources, and beautiful scenery. This makes volcanic risk management one of the most important challenges in natural hazard science.
At night, active lava glows a brilliant orange and red, and the glow from a large eruption can be visible from hundreds of kilometres away. Erupting volcanoes have been described by witnesses as the most breathtaking natural spectacles on Earth.