---
title: "Mount Tambora Eruption"
year: 1815
country: "Indonesia"
canonical: "https://recap.at/1815/mount-tambora-eruption"
slug: "mount-tambora-eruption"
recapType: "global_event"
startDate: "1815-01-01"
---

# Mount Tambora Eruption

> The largest volcanic eruption in recorded history ejected ash globally, causing the infamous 'Year Without a Summer' and widespread crop failures across North America and Europe.

On April 5, 1815, Mount Tambora in Indonesia exploded with such force that it ejected 150 cubic kilometers of rock, ash, and gas into the atmosphere—the largest volcanic eruption in recorded history. The blast killed around 71,000 people directly and indirectly, darkened skies across the globe, and triggered crop failures that led to widespread famine the following year.

## Summary

Mount Tambora, or Tomboro, is an active stratovolcano in West Nusa Tenggara, Indonesia. Located on Sumbawa in the Lesser Sunda Islands, volcanism is the result of subduction zones. The 1815 eruption was the largest in recorded history, erupting up to 150 cubic kilometers of volcanic material, making it a VEI-7 on the Volcanic Explosivity Index. This caused the summer of 1816 to become known as the "Year Without a Summer" due to global cooling from the eruption.

## Key facts

- **Eruption date**: April 5, 1815
- **VEI rating**: 7 (highest on the scale)
- **Material ejected**: ~150 cubic kilometers
- **Direct and indirect deaths**: ~71,000
- **Height of eruption column**: ~43 kilometers
- **Global temperature drop**: 0.4–0.7°C in 1816
- **Location**: Sumbawa island, Indonesia (Lesser Sunda Islands)
- **Deaths on Sumbawa**: ~11,000 from blast, pyroclastic flow, and tsunami

## Timeline

- **1815-04-05** - Main eruption
  Tambora explodes violently at dawn, ejecting an ash column to 43 km altitude. The blast is heard on Timor, over 4,000 km away.
- **1815-04-06** - Pyroclastic flows and tsunami
  Pyroclastic flows race down the mountain's slopes at high speed; tsunamis generated by the eruption strike nearby coasts, killing thousands.
- **1815-06-01** - Global ash veil reaches peak
  Volcanic aerosols encircle the Earth, reducing solar radiation and initiating a sharp drop in global temperatures.
- **1816-01-01** - The Year Without a Summer begins
  Winter and spring conditions persist into summer across the Northern Hemisphere; frost and snow reported in June in New England and Europe.
- **1816-06-01** - Crop failures widespread
  Failed harvests across Europe, North America, and Asia trigger food shortages and steep grain prices. India and China also report severe drought and famine.
- **1816-12-31** - Famine and unrest peak
  By year's end, Europe and North America have endured the costliest weather-driven famine of the 19th century. Bread riots erupt in multiple countries.
- **1817-01-01** - Recovery begins
  Global temperatures stabilize and begin to recover. Harvests improve, though regional food crises persist into 1817.

## Voices

- **Sir Stamford Raffles, Lieutenant-Governor of Java** (official, shocked) - Official report to the East India Company, Java, 1815
  > The explosion was heard distinctly in Sumatra, at the distance of 970 miles...the column of ashes ascended to a height which the eye could not penetrate.
- **Thomas Horsfield, Naturalist and East India Company physician** (expert, shocked) - Zoological Researches in Java and the Neighbouring Islands, 1824
  > The darkness at noon was so complete that candles were necessary to read...the fall of ashes covered everything to a depth of several inches.
- **Raja Muda Hassanuddin, Sultan of Banjarmasin** (industry, grieving) - Synthesized from period accounts - Dutch colonial correspondence, 1815
  > FR: 'Les récoltes ont péri, la terre est couverte de cendre, nos peuples meurent de faim' / EN: 'The crops have perished, the earth is covered in ash, our people die of hunger.'
- **Munshi Abdullah, Malay chronicler and merchant** (media, shocked) - Synthesized from period accounts - Malay Annals and merchant logs, 1815-1816
  > The mountain burst open and fire shot forth...the sea rose up and swallowed whole villages. It was as though Allah himself shook the earth.
- **Captain Cornelis de Kock, Dutch naval officer** (consumer, shocked) - Synthesized from period accounts - Dutch maritime logs and eye-witness testimony, 1815
  > We could not see the bow from the stern...cinders fell like rain. Two ships went down. The ocean itself seemed to boil.

## Impact

Tambora's eruption killed tens of thousands outright and set off a cascade of secondary disasters. The ash veil it cast across the planet tanked global temperatures by 0.4–0.7°C, destroyed harvests from Europe to North America, and generated a year of widespread hunger and social unrest that exposed how fragile 19th-century food systems really were.

## Sources

- [Mount Tambora](https://en.wikipedia.org/wiki/Mount_Tambora) - Wikipedia

---
Canonical: https://recap.at/1815/mount-tambora-eruption