Volcanoes Facts for Kids
Explosive facts about volcanoes and geology
Volcanologists use the word 'tephra' for any material thrown into the air during an eruption, from fine ash to house-sized boulders called volcanic bombs.
The magma chamber beneath Yellowstone is estimated to be about 90 kilometres long, 30 kilometres wide, and up to 15 kilometres deep β large enough to fill the Grand Canyon more than 11 times over.
The island of Surtsey, off the coast of Iceland, was born from an underwater volcanic eruption that began in 1963. Scientists have watched life slowly colonise it ever since.
Iceland generates about 25% of its electricity from geothermal energy β heat from volcanic activity underground. Many homes are also heated this way.
The Volcanic Explosivity Index (VEI) ranks eruptions on a scale from 0 to 8. Each step represents a tenfold increase in material ejected, making a VEI 8 eruption 100 million times more powerful than a VEI 0.
Cryovolcanoes, or ice volcanoes, erupt ice, water, and ammonia instead of molten rock. They have been found on Saturn's moon Enceladus and Neptune's moon Triton.
Obsidian, a type of volcanic glass, was used by ancient peoples to make sharp tools, arrowheads, and mirrors. It can be sharper than a surgical scalpel!
Volcanic hotspots are plumes of abnormally hot mantle material that rise independently of plate boundaries. As tectonic plates drift over these stationary hotspots, they create chains of volcanoes like the Hawaiian Islands.
The Kawah Ijen volcano in Indonesia produces stunning blue flames at night. The flames come from burning sulphur gases that escape from cracks in the volcano.
Lahars β volcanic mudflows made of ash and water β can race down valleys at over 60 kilometres per hour. They can travel more than 100 kilometres from the volcano and bury entire villages.