April 10, 1815: The Biggest Eruption in Recorded History
Mount Tambora, a stratovolcano on Sumbawa Island in Indonesia, had been grumbling since 1812 — small eruptions and rumbling that the local Sanggar and Tambora kingdoms had learned to live with. Nobody expected what came next.
On the evening of April 10, Tambora detonated. The eruption column punched 43 km into the stratosphere. The sound was heard 2,600 km away on Sumatra — roughly the distance from London to Moscow. British soldiers in Java (1,300 km away) thought they were hearing cannon fire and sent troops to investigate a nonexistent attack.
The eruption ejected roughly 37–41 km³ of material (dense rock equivalent), collapsing Tambora from 4,300 m to 2,850 m — the mountain lost more than a third of its height overnight. The resulting caldera was 6 km across and 1,100 m deep.
Pyroclastic flows swept down all flanks, reaching the sea and generating tsunamis that battered neighboring islands. Sumbawa was plunged into total darkness for up to three days. An estimated 10,000 people died immediately from the eruption itself. Over the following months, at least 61,000 more died from starvation and disease as crops were buried under thick ash, water sources poisoned, and the local economy collapsed.
For context, the 1883 Krakatoa eruption — often considered the most famous volcanic disaster — was roughly 10 times smaller than Tambora.
1816: When Summer Never Came
The eruption injected massive quantities of sulfur dioxide into the stratosphere, where it combined with water to form a veil of sulfuric acid aerosols. This aerosol cloud — roughly the size of Australia — reflected incoming sunlight back into space. Global temperatures dropped by 0.4–0.7°C (0.7–1.3°F). That doesn't sound catastrophic — until you look at what it did to agriculture.
The Northern Hemisphere summer of 1816 was the coldest in at least 200 years. Historian John D. Post called it "the last great subsistence crisis in the Western world." Here's what happened, month by month:
The Cholera Pandemic Nobody Connects to a Volcano
This is the part most articles leave out. Tambora's stratospheric aerosols didn't just cool Europe and North America — they disrupted the Asian monsoon system. Rainfall patterns in India were severely altered through 1816 and 1817.
In the abnormal monsoon conditions, a new, more virulent strain of Vibrio cholerae emerged in the Bengal region of India. By 1817, it had exploded into the first cholera pandemic — the first truly global outbreak, sweeping from India through Southeast Asia, the Middle East, eastern Africa, and eventually Europe. It killed hundreds of thousands directly and millions over the subsequent pandemic waves it spawned.
The causal chain — volcanic aerosols disrupting monsoons, monsoon disruption altering water conditions, altered conditions enabling a bacterial mutation — isn't proven beyond doubt. But the temporal correlation is striking, and several epidemiological studies have argued the connection is more than coincidental. A single volcanic eruption may have launched the disease that reshaped global public health.
How Frankenstein Was Born in a Volcanic Winter
June 1816, Villa Diodati, Lake Geneva. Mary Godwin (later Mary Shelley), age 18, was staying with Percy Bysshe Shelley, Lord Byron, and Byron's physician John Polidori. They had come to Switzerland for a summer holiday. But summer never arrived.
Cold, relentless rain confined them indoors. The skies were dark and strange — Tambora's aerosols had turned Swiss sunsets an eerie blood-red. Byron, bored and brooding, proposed a ghost story competition. Each member of the party would write a tale of supernatural horror.
Mary Shelley's contribution became Frankenstein; or, The Modern Prometheus, published in 1818 — one of the foundational novels of science fiction and Gothic horror. Polidori wrote The Vampyre, the first modern vampire story in English, which directly influenced Bram Stoker'sDracula. Byron himself wrote "Darkness," a poem that reads like a dispatching from the end of the world:
"I had a dream, which was not all a dream. / The bright sun was extinguish'd, and the stars / Did wander darkling in the eternal space..."
— Lord Byron, "Darkness" (July 1816)
One volcanic eruption, 14,000 km away, catalyzed two of the most enduring horror archetypes in Western literature. The volcanic winter's influence went further: painter J.M.W. Turner's famously luminous sunsets from this period are now attributed to Tambora's stratospheric particles scattering light.
The Science: How Volcanoes Change Climate
Not every eruption cools the planet. The key variable is stratospheric sulfur injection — how much SO2 gets above the tropopause (~10–15 km altitude), where it can form a persistent aerosol veil instead of being washed out by rain within weeks.
Tambora's eruption column reached 43 km — well into the stratosphere. The SO2 converted to sulfuric acid droplets that spread across both hemispheres over months, reflecting roughly 1–2% of incoming solar radiation. The effect peaked in the year following the eruption and lasted roughly 3–5 years as the aerosols slowly settled out.
For comparison: the 1991 Pinatubo eruption (VEI 6, about 10 times smaller than Tambora) cooled the planet by 0.5°C for about 2 years. Tambora's VEI 7 produced proportionally larger and longer-lasting effects. Only VEI 6 or higher eruptions reliably produce measurable global climate impacts.
Could It Happen Again?
Almost certainly — it's a question of when, not if. VEI 7 eruptions occur roughly every 500–1,000 years on average, and we're 211 years past Tambora. Here's what our database tells us about the largest eruptions and their climate effects:
The candidates for the next VEI 7 are the usual suspects: Campi Flegrei (currently in accelerating unrest, with peer-reviewed research projecting a critical transition by 2033), various Indonesian subduction zone volcanoes, or a caldera system not currently on anyone's radar.
Modern agriculture and global supply chains would buffer the worst effects — we wouldn't see the famine of 1816 in developed nations. But a VEI 7 eruption today would cause severe food price spikes, grounding of aviation over large areas, disruption of solar energy production, and regional famine in food-insecure countries. A 2019 analysis in the journal Nature Food estimated that a Tambora-scale eruption today could reduce global crop yields by 20–30% for 1–2 years.
For more on how the Yellowstone supervolcano compares to Tambora, see our dedicated guide. Yellowstone's largest eruptions were VEI 8 — an order of magnitude beyond Tambora. But its last eruption was 70,000 years ago, and USGS classifies it as "Normal."
Tambora Today: Quiet but Not Extinct
Mount Tambora stands at 2,850 m today — down from its pre-1815 height of roughly 4,300 m. The 6 km caldera created by the eruption contains a small seasonal lake. The volcano is classified as active — our database records 7 eruptions total, with the most recent activity in 1967 (a very small event, VEI 0). Fumarolic activity continues inside the caldera.
Sumbawa Island is now home to roughly 1.5 million people. The area around Tambora is agricultural — rice paddies and coffee plantations cover the lower slopes, nourished by the nutrient-rich volcanic soil. In 2004, archaeologists discovered the "Pompeii of the East" — a buried village on Tambora's flanks, preserved under pyroclastic deposits from 1815, complete with houses, pottery, bronze tools, and carbonized remains. The excavation of this "Tambora culture" is ongoing.
The area is remote — no direct flights to Sumbawa, and reaching the caldera requires a multi-day trek from the nearest town (Pancasila). A handful of trekking operators offer guided expeditions to the caldera rim for roughly $200–400 per person over 2–3 days. It's not a tourist volcano — it's an expedition.
Explore Tambora in Our Database
Full eruption history, coordinates, VEI data, and geological classification for Mount Tambora