10 Facts About The 1815 Eruption of Mount Tambora


Mount Tambora is an active volcano on the island of Sumbawa in Indonesia. Its eruption in 1815 is the most powerful volcanic eruption in recorded history and is considered one of the greatest natural disasters ever to befall mankind. Apart from killing tens of thousands of people and plunging South East Asia into darkness, it also had other environmental consequences including what is known as the Year Without A Summer. Here are 10 interesting facts about Mount Tambora’s 1815 eruption.


#1 It is a Stratovolcano

Mount Tambora is a stratovolcano. They are characterized by a steep profile unlike shield volcanoes which have a low profile and are spread out like a warrior’s shield lying on the ground. The lava flowing from a stratovolcano is more viscous as compared to a shield volcano and thus it cools and hardens before spreading wide. Mount Tambora experienced centuries of dormancy but by 1812 it had entered a period of high activity. It is estimated that small eruptions occurred for three years before the violent eruption of April 1815.

Mayon Volcano 2009 eruption
Mayon Volcano in Philippines, a stratovolcano, erupted on December 29, 2009


#2 The initial eruption of Mount Tambora was thought to be cannon fire 1260km away

On the evening of April 5, 1815, a massive explosion occurred at Mount Tambora which was heard as far as 1,400 km away at Ternate, an island in the Maluku Islands. In Java, which is 1,260 km from Mount Tambora, British authority mistook the sound for cannon fire. Fearing a neighboring post was under attack, troops were dispatched from Djogjokarta, in central Java, to repel the invaders. Along the coast the officials thought that a ship was under distress and rescue boats were sent.

Mount Tambora location
The location of Mount Tambora in Indonesia


#3 Mount Tambora eruption wiped out the village of Tambora

On 10 April, 1815, Mount Tambora erupted even more violently with three columns of flaming lava rising to a great height and merging together. The whole mountain turned into a flowing mass of “liquid fire”. The village of Tambora, which was near the volcano, was wiped out. Pumice stones of up to 20 cm (7.9 in) in diameter rained down upon the village of Sanggar, nineteen miles away. Large explosions occurred till the evening of April 11.


#4 It plunged South East Asia into darkness

Pumice is created when super-heated, highly pressurized rock is violently ejected from a volcano. Its density varies and it might float on water. The eruption of Tambora created pumice rafts in the surrounding seas which, like giant icebergs, remained a hazard to ships for many years. Also the eruption created an umbrella of volcanic ash which spread and blanketed South East Asia plunging it into darkness for a week.

1815 Tambora eruption volcanic ashfall regions
The estimated volcanic ashfall regions during the 1815 Tambora eruption


#5 The eruption blew off the top 4000ft of the mountain

Mount Tambora was formed by the active subduction zone beneath it. By the eighteenth century it reached a height of around 4,300 m (14,100 ft) making it one of the tallest peaks in the Indonesian archipelago. However after the eruption it measured only 2,851 m (9,354 ft) (about two thirds of its previous height). The explosion destroyed the top one third of the peak leaving behind a large crater three miles wide and half a mile deep.

Aerial view of Mount Tambora
Aerial view of the crater of Mount Tambora, formed during the colossal 1815 eruption


#6 With a death toll of more than 71,000 it is one of the deadliest volcanic eruptions

11,000–12,000 people were killed directly by the eruption of Tambora. It led to several Indonesian islands being struck by tsunami waves reaching heights up to 4 m (13 ft), further increasing the death toll. Eruptive fallout ruined agricultural productivity in the local region leading to famine and diseases which were responsible for most of the deaths. The death toll of Mount Tambora eruption varies according to different sources but it is estimated to be at least 71,000.

Major volcanic eruptions fatalities table
Table of estimated deaths caused due to some of the major volcanic eruptions


#7 Mount Tambora eruption is the most powerful in recorded history

The volcanic explosivity index (VEI) is used to measure the explosiveness of volcanic eruptions. 1815 eruption of Mount Tambora is classified as a VEI-7 event, i.e. it ejected more than 100 cubic kilometres of tephra (material produced by a volcanic eruption) and the eruption cloud height was more than 40km. Mount Tambora eruption is the most powerful volcanic eruption in recorded history with an estimated 160 cubic kilometres of tephra ejected and a 45 meter tall eruption column.

Volcanic Explosivity Index volume graph
Volcanic Explosivity Index volume graph


#8 It led to drop in global temperatures

Cover of book on Mount Tambora eruption
Cover of a book on Mount Tambora eruption and the Year Without a Summer

Mixed with the material that flowed out of Mount Tambora were millions of tonnes of sulfur dioxide. A large portion of this rose up into the stratosphere and spread around the equator and towards the poles. The sulfur dioxide then oxidized to form sulfate ions. These developed into tiny particles which reflected a fraction of the light from the sun. With less sunlight, global temperatures dropped. As the sulfate ions were small enough to stay afloat for many months, the cooling continued into the following year.

#9 It is one of the greatest environmental disasters

1816, the year following the eruption, is known as the Year Without a Summer. Average global temperatures decreased about 0.4–0.7 °C (0.7–1.3 °F). There were severe climate anomalies with snow in unusual months. Northern hemisphere was hardest hit. Most agriculture crops were ruined in North America. There was famine in several countries. Thousands of people perished due to floods, droughts, starvation and disease. An estimated 100,000 deaths resulted in Europe alone. Also it gave rise to a new and deadly strain of cholera which first hit the Bay of Bengal in India and eventually spread across the globe. By century’s end, the death toll from Bengal cholera stood in tens of millions. Mount Tambora eruption is thus placed among the greatest environmental disasters ever to befall mankind.

A graph illustrating the year without a summer
1816 summer temperature anomaly with respect to 1971-2000 climatology


#10 Mount Tambora is known as the Pompeii of the East

In 2004, a team of archaeologists discovered artifacts and bodies of two adults buried by the eruption. Volcanic material had preserved them in the position they had occupied in 1815. This was similar to the rediscovery of Pompeii, which was destroyed by the eruption of Mount Vesuvius in 79 A.D. and is known as the City of the Dead due to the casts of victims. The discovery of 2004 has led to Mount Tambora being nicknamed “the Pompeii of the East.”

Tambora eruption victim remains
Remains of a victim of the Tambora eruption who was caught by the pryoclastic flow


A Tambora sized eruption 30% likely this century

200 years have passed since the Tambora eruption. In May 2015 there was a report published by Cambridge University Press which was titled “Global Volcanic Hazards and Risk”. Prepared for the United Nations by an international team of expert, it said that there was a 30% likelihood of an eruption of a magnitude similar to Tambora striking in this century. It put Indonesia at maximum risk followed by Philippines, Japan, Mexico, Ethiopia, Guatemala, Ecuador, Italy, El Salvador and Kenya.

19 thoughts on “10 Facts About The 1815 Eruption of Mount Tambora”

  1. As we become increasingly concerned about climate change, there is a tendency to consider it a matter of “global warming” caused by human activities. Tambora and Krakatoa events are a reminder of climate change unrelated to human activities.


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