50 Volcano Facts, Backed by Real Data

Our database catalogs 1,740 volcanoes worldwide, 1,282 of them active in the Holocene — the last ~12,000 years. See them all on our volcano map.

Between them, those volcanoes account for more than 11,000 recorded eruptions in our database, drawn from the Smithsonian Global Volcanism Program.

In any given year only about 40–50 volcanoes erupt, and roughly 20 are actively erupting on any single day (Smithsonian GVP). Track them on our active volcanoes page.

About 800 million people live within 100 km of an active volcano, and over 1 billion live within 100 km of a Holocene volcano (JRC/MDPI global study, 2015).

The Pacific Ring of Fire hosts about 75% of the world's volcanoes and 90% of its earthquakes (National Geographic; Britannica).

More than three-quarters of Earth's volcanic activity happens unseen — underwater, along the mid-ocean ridges (NOAA).

Indonesia packs in 138 volcanoes in our database — behind only the United States (205) and Russia (151), but in a fraction of the area.

The single most-recorded volcano in our database is Piton de la Fournaise on Réunion Island, with 203 logged eruptions.

Japan's Aso (187 eruptions) and Italy's Etna (170) come next — and Etna has kept erupting through 2026.

The word "volcano" comes from Vulcano, an Italian island named for Vulcan, the Roman god of fire (Oregon State Volcano World).

Stratovolcanoes — the steep, layered cones like Fuji and Vesuvius — are the most common type: 681 in our database.

Shield volcanoes, built by fluid lava into broad, gentle domes like Hawaii's, number 148.

259 of our entries are volcanic fields — scatterings of small vents rather than a single peak.

91 are calderas: giant craters left when a volcano collapses into its emptied magma chamber.

Most of the world's volcanoes form above subduction zones, where one tectonic plate dives beneath another.

A few — Hawaii and Yellowstone among them — sit over hotspots: plumes of heat rising through the middle of a plate.

Basaltic lava, the runny kind, erupts at about 1,000–1,200°C (Oregon State Volcano World).

Molten rock is called magma underground and lava only once it reaches the surface — same material, different name.

An eruption's explosive power is measured on the Volcanic Explosivity Index (VEI), a 0–8 scale.

The VEI is logarithmic: each step up represents roughly a tenfold jump in the volume of material erupted.

The highest volcano on Earth is Ojos del Salado on the Chile–Argentina border, at 6,879 m — see the full ranking of the biggest volcanoes.

The tallest volcano in the solar system is Mars's Olympus Mons — about 26 km high, three times Everest, with a base the size of Arizona (Britannica; Space.com).

Only 7 eruptionsin our database reached VEI 7, the "super-colossal" tier — and none reached VEI 8 in the Holocene.

Those seven are Kikai, Kurile Lake, Crater Lake, Cerro Blanco, Santorini, Rinjani (1257) and Tambora (1815).

Tambora's 1815 eruption is the only VEI 7 in the last 500 years — the largest eruption of recorded history.

Shiveluch in Kamchatka has more VEI-4-plus eruptions on record than any other volcano in our database — 43 — as our most explosive volcanoes ranking shows.

The 1883 Krakatoa eruption produced the loudest sound in recorded history, heard about 4,800 km away (Britannica).

Krakatoa's pressure wave was strong enough to register on barometers around the entire planet.

Toba's super-eruption ~74,000 years ago is among the largest known, leaving a 100-km-long lake-filled caldera in Sumatra.

A volcano's deadliest product, pyroclastic flows, can reach about 700 km/h and 1,000°C (Britannica; USGS).

In 79 CE, Vesuvius buried Pompeii and Herculaneum under ash and pyroclastic surges.

The deadliest eruption of the 20th century was Mont Pelée in 1902, which destroyed the town of Saint-Pierre, Martinique.

Nevado del Ruiz's 1985 eruption killed about 23,000 — almost entirely from lahars, not lava. See the full list of deadliest eruptions.

Lahars — volcanic mudflows — can travel tens of kilometers beyond an eruption, following river valleys downhill.

Mount St. Helens' 1980 eruption blew out its north flank in the largest landslide in recorded history.

Mount Sinabung in Indonesia stayed silent for roughly 1,200 years before roaring back to life in 2010.

Kilauea in Hawaii is one of the most active volcanoes on Earth, and has been erupting in fountaining episodes since 2024.

The Campi Flegrei caldera near Naples has been slowly inflating for years, lifting the ground beneath a major city.

Yellowstone is a supervolcano, but its last super-eruption was about 640,000 years ago.

"Supervolcano" isn't official jargon — it just means any volcano capable of a VEI-8 eruption.

Mount Erebus in Antarctica holds one of the world's only persistent lava lakes — and the planet's southernmost active volcano.

Volcanic lightning can crackle inside ash plumes, generated by static from colliding ash particles.

Big eruptions can cool the whole planet: Tambora's 1815 blast caused 1816, the "Year Without a Summer".

There are volcanoes made of mud, not lava — hundreds of them, driven by gas and water rather than magma.

Some volcanoes erupt not from a peak but from long cracks in the ground, called fissure eruptions.

Cooling lava can leave hollow tunnels called lava tubes, some kilometers long and tall enough to walk through.

Volcanic islands like Hawaii and Iceland are simply volcanoes that grew tall enough to break the ocean's surface.

Iceland straddles a mid-ocean ridge, so it's being pulled apart and built up by volcanism at the same time.

A quiet volcano isn't a dead one: dormant volcanoes can reawaken, as Sinabung and Puracé recently did.

You can explore all 1,740 of them, plotted and searchable, on our interactive volcano map.