Image description: The Yellowstone supervolcano (VEI index = 8) is located in the Northwest of the United States, near the Rocky Mountains. The Yellowstone region is the result of a gigantic eruption that occurred 642,000 years ago.
Supervolcanoes are volcanoes capable of producing eruptions of exceptional magnitude. Supervolcanoes have a flattened structure and are difficult to detect. It is only after they have exploded, when the underground magma chamber collapses, that the famous caldera becomes visible on the ground. These calderas, several tens of kilometers in size, are so large that they can only be detected from an aerial view.
Supervolcanoes, like regular volcanoes, are located in areas of intense geological activity, including earthquakes, volcanic eruptions, or mountain formation. These areas define the boundaries between lithospheric plates (7 major plates and 20 minor ones), and volcanoes and supervolcanoes are found along tectonic zones.
The main tectonic plates define the lines of seismic activity. Among these plates are the North American, South American, Eurasian, African, Pacific, Australian, and Antarctic plates. Supervolcanoes cause super-eruptions that are unlike the typical eruptions we observe on Earth.
Humanity has not yet witnessed a super-eruption. These super-eruptions can cause considerable damage on a continental scale and have cataclysmic effects on life on Earth. The most recent recorded supervolcano explosion occurred about 26,500 years ago, at Lake Taupo in New Zealand.
The eruption of the Indonesian supervolcano on the island of Toba, about 73,000 years ago, spewed an impressive amount of ash, estimated at nearly 2,800 cubic kilometers. In comparison, the eruption of Pinatubo in the early 1990s emitted only 10 cubic kilometers of ash. The ash from Pinatubo altered Earth's albedo and lowered its average temperature by 0.6°C for two years. In 1998, Stanley Ambrose, an anthropology professor at the University of Illinois, estimated that the Toba eruption caused a global cooling of the planet for 1,800 years. Most supervolcanoes are extinct.
N.B.: The VEI index provides a relative measure of the explosivity of volcanic eruptions. This Volcanic Explosivity Index, or VEI scale, was invented by Chris Newhall of the United States Geological Survey and Steve Self of the University of Hawaii in 1982.
Image description: Nestled in the heart of the Sumatran equatorial forest, the Toba caldera measures 30 km wide by 100 km long. The ancient caldera is filled by a lake in the middle of which is the island of Samosir, materializing the ancient dome of the volcano.
Mauna Loa is the largest
volcano in the world! 
Effusive and eruptive volcanoes
of the Earth 
Kamchatka, exceptional land of
fire 
The active volcanoes of
Colombia 
New Zealand volcanoes 
Volcanoes at the origin of life 
The great ocean trenches 
Birth of an island,
rising from the waters 
Chimborazo
in Ecuador, the highest mountain in the world 
Super eruption disaster 
Africa's Active Volcanoes 
Supervolcanoes are invisible! 
The Nevado del Ruiz volcano
The Phlegraean Fields 
The Yellowstone Supervolcano 
The spectacular caldera of Lake Taupo