Volcanoes Facts for Kids
Explosive facts about volcanoes and geology
Mayon Volcano in the Philippines is famous for having nearly the perfect symmetrical cone shape of any volcano on Earth. Despite its beauty, it is also one of the most dangerous volcanoes in Southeast Asia, having erupted over 50 times in recorded history.
Volcanoes that erupt beneath glaciers form distinctive flat-topped mountains called tuyas or table mountains. As lava pours into the water formed by melting ice, it piles up vertically instead of spreading out, creating a distinctive mesa-like shape.
Yellowstone National Park contains about 10,000 thermal features, including more than half of the world's geysers, thousands of hot springs, fumaroles, and bubbling mud pots β all powered by the same underground supervolcano.
Some volcanic islands are temporary. Lava builds them up above sea level, but wave erosion and the sinking of the ocean crust under their own weight can pull them back below the ocean's surface over thousands of years.
Scientists measure the ratio of sulfur dioxide to carbon dioxide gas coming out of a volcano to gauge eruption risk. When the SO2/CO2 ratio rises sharply, it signals that fresh magma is rising β a critical warning sign of impending activity.
During the most violent supervolcanic eruptions, rivers of hot ash and pumice called pyroclastic density currents can spread hundreds of miles and weld themselves into solid rock sheets called ignimbrites. Some ignimbrite deposits in New Zealand are over 300 feet thick.
Campi Flegrei ('Burning Fields') is a vast volcanic caldera on the western edge of Naples, Italy, with roughly 3 million people living on top of it. Scientists classify it as on 'yellow alert' β it has been slowly swelling and increasing seismic activity for years.
Neptune's moon Triton has geysers that shoot nitrogen gas several miles above its surface β a form of cryovolcanism powered by solar heating of its thin atmosphere rather than internal heat. Voyager 2 photographed these geysers during its 1989 flyby.
The summer of 1816 was so cold from the aftermath of the Tambora eruption that it snowed in New England in June and July. The failed harvests inspired Mary Shelley, who was stuck indoors during a stormy summer in Switzerland, to write the novel Frankenstein.
Tungurahua volcano in Ecuador, whose name means 'throat of fire' in the local Quechua language, has been in a state of ongoing unrest since 1999. It regularly hurls volcanic bombs and produces ash plumes that force the evacuation of surrounding communities.