What If UniverseOpen the simulatorVolcano eruption simulator
Pick one volcano, a handful or all of them, or set off a supervolcano like Yellowstone, and watch the ash clouds drift around the planet with the wind.
Try it now: free, in your browser
Eruptions and supervolcanoes
The globe holds about 1,600 volcanoes that have been active since the last ice age. Erupt any of them and their ash is carried by a moving wind field. The simulator counts the people under the ash and those killed by ash flows and mudslides near the vents.
Supervolcanoes are in a class of their own. Yellowstone, Toba and Campi Flegrei bury whole regions in ash, and the sulphur they throw into the stratosphere cools the planet for years. Tambora in 1815 caused "the year without a summer"; Pinatubo in 1991 cooled the Earth by about half a degree.
Erupting every volcano at once adds up to a volcanic winter of several degrees, with failed harvests and famine as the main killers.
Questions
What would happen if Yellowstone erupted?
A full super-eruption would bury much of the United States in ash and cool the planet by several degrees for years. In the simulator it kills tens of thousands nearby and causes famine worldwide.
Would all volcanoes erupting at once end the world?
No, but it would be one of the worst disasters in human history. Most volcanoes are small, and the cooling fades after two or three years. The simulator ends up at about a third of humanity dead, mostly from hunger.
Where does the volcano data come from?
The list of volcanoes comes from NOAA's National Centers for Environmental Information.
All numbers in the simulator are rough estimates meant to show what could happen, not predictions.