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Mount Tambora


Tambora seen from space
Elevation: 2,850 metres (9,350 feet)
Latitude: 8° 15′ 0″ S
Longitude: 118° 0′ 0″ E
Location: Lesser Sunda Islands (Indonesia)
Range: n/a
Type: Stratovolcano

Mount Tambora is a volcano on the Indonesian island of Sumbawa. In 1815, the volcano of Tambora suffered the most violent eruption in modern times. Beginning in early April 1815 and continuing through the middle of July 1815, its explosion affected an immense area that included the Maluku Islands (Molucca Islands), Java, and portions of Sulawesi (Celebes), Sumatra, and Borneo. Heavy ashrains also specifically affected the islands of Bali and Lombok.


The most violent eruption in recorded history

Mount Tambora erupted on April 10, by most accounts, and the eruption lasted from April 10 to April 15. The explosion, of Volcanic Explosivity Index 6-7, ejected an estimated 100 cubic km of melted rock, weighing approximately 2-3 × 1014 kg. This left a caldera 7km (4 mi) across. Before the explosion, Mount Tambora was approximately 4200m (13,000 ft) high; after the explosion, it was only 2851m (about 9,000 ft) high. Tambora was not, however, the most violent volcanic eruption of all time. The eruption of Santorini (Thira) in Greece in about 1650 BC was greater, but no accounts of the explosion survive, possibly because it destroyed nearby the civilisations which recorded it. A much larger eruption of Toba roughly 75,000 years ago has been theorized to have reduced the worldwide population of mankind (Homo erectus, Homo neanderthalensis, and Homo sapiens) at the time to just a few thousand individuals, though definite evidence is lacking. One of the greatest known eruptions was of the Yellowstone Caldera about 2,000,000 years ago, an event which almost certainly caused an extended period of volcanic winter with far-reaching effects. Even greater undiscovered cataclysmic eruptions have certainly occurred in the Earth's 4.7 billion year history.


All vegetation on several nearby islands was destroyed. About 10,000 people died immediately from the eruption, with about 82,000 dying from later consequences of the disaster. Worldwide deaths caused by starvation and disease due to climate change are more difficult to quantify.

The eruption sent so much volcanic ash into the atmosphere that weather patterns around the world were altered, causing the following year to be nicknamed the "Year Without a Summer".

Quotes from 1815 accounts of the eruption

Metric values added where possible


"The concussions produced by its explosions were felt at a distance of a thousand miles (1600km) all round; and their sound is said to have been heard even at so great a distance as seventeen hundred miles (2700km). In Java the day was darkened by clouds of ashes, thrown from the mountain to that great distance (three hundred miles or 500km), and the houses, streets, and fields, were covered to the depth of several inches with the ashes that fell from the air. So great was the quantity of ashes ejected, that the roofs of houses forty miles (65km) distant from the volcano were broken in by their weight. The effects of the eruption extended even to the western coasts of Sumatra, where masses of pumice were seen floating on the surface of the sea, several feet in thickness and many miles in extent."

Pyroclastic flow

"From the crater itself there were seen to ascend three fiery pyroclastic columns, which, after soaring to a great height, appeared to unite in a confused manner at their tops. Soon, the whole of the side of the mountain next to the village of Sang'ir seemed like one vast body of liquid fire. The glare was terrific, until towards evening, when it became partly obscured by the vast quantities of dust, ashes, stones, and cinders thrown up from the crater. Between nine and ten o'clock at night the ashes and stones began to fall upon the village of Sang'ir, and all round the neighbourhood of the mountain."

Atmospheric disturbance

"The heat triggered a 'dreadful whirlwind', which blew down nearly every house in the village, tossing the roofs and lighter parts high into the air. In the neighbouring sea-port the effects were even more violent, the largest trees having been torn up by the roots and whirled aloft. Before such a furious tempest no living thing could stand. Men, horses, and cattle were whirled into the air like so much chaff, and then dashed violently down on the ground. The sea rose nearly twelve feet above the highest tide-mark, sweeping away houses, trees, everything within its reach. This whirlwind lasted about an hour."

Gradual decrease

"The 'awful internal thunderings of the mountain' continued with scarcely any intermission until the 11th of July, when they became more moderate, the intervals between them gradually increasing till the 15th of July, when they ceased. Almost all the villages for a long distance round the mountain were destroyed. By far the greatest part of this destruction was wrought by the violence of the whirlwind which accompanied the eruption."

See also

External links

Last updated: 08-17-2005 13:47:32
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