Tambora
Missing image Map_indonesia_volcanoes.gif Tambora
Elevation:	9,350 ft (2,850 m)
Latitude:	8° 15′ 0″ S
Longitude:	118° 0′ 0″ E
Location:	Lesser Sunda Islands
Range:
Type:	Stratovolcano

Mount Tambora is a volcano on the Indonesian island of Sumbawa, nearly in a right line to the eastward of Java. The volcano of Tambora suffered the most violent eruption in modern times. HiBeginning in early April 1815 and continuing till the middle of July 1815, its immediate explosion effects were felt over an immense area, embracing the Maluku Islands (Molucca Islands), Java, and portions of Sulawesi (Celebes), Sumatra, and Borneo.

Contents

1 The most violent eruption in recorded history 1.1 Effects 2 Quotes from 1815 accounts of the eruption 2.1 Explosion 2.2 Lava flow 2.3 Atmospheric disturbance 2.4 Gradual decrease 3 See also 4 External links

The most violent eruption in recorded history

The mountain blew its top off on April 12, by most accounts, with the most violence between April 10 and April 15. The explosion, of Volcanic Explosivity Index 6-7, ejected an estimated 100 cubic km of rock, weighing approximately 2-3 × 10¹⁴ kg. This left a caldera 7km across. Before the explosion, Mount Tambora was about 4000m high; it is now only 2851m 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 of the destruction it caused to nearby civilisations. A much larger eruption of Toba roughly 75,000 years ago has been theorized to have reduced the worldwide population of mankind (Homo erectus and Homo neanderthalensis) 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.

Effects

All vegetation on several nearby islands died. All in all, about 92,000 people died as a direct consequence of this disaster. Indirectly a similar number died worldwide as a result of starvation and disease.

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

Explosion

"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."

Lava flow

"From the crater itself there were seen to ascend three fiery 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

The Krakatoa volcanic explosion, Indonesia 1883.

External links

• Tambora USGS (http://vulcan.wr.usgs.gov/Volcanoes/Indonesia/description_tambora_1815_eruption.html)
• Tambora nodak edu (http://volcano.und.nodak.edu/vwdocs/volc_images/southeast_asia/indonesia/tambora.html)

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