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Mount Tambora

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Mount Tambora
Map
Highest point
Elevation2,850 m (9,350 ft) Edit this on Wikidata
Prominence2,722 m (8,930 ft) Edit this on Wikidata

Mount Tambora is a stratovolcano on the Indonesian island of Sumbawa which erupted in 1815. The eruption registered seven on the Volcanic Explosivity Index, making it the most violent eruption in modern history.[2] The explosion was heard on Sumatra island (more than 2,000 km away), and heavy volcanic ash rains were observed as far away as Borneo, Makassar on Sulawesi island, Central Java and the Maluku islands. At least 71,000 people were killed, of which 11,000–12,000 were killed directly by the eruption.[3]

The eruption created global climate anomalies in the years following. 1816 became known as the Year Without a Summer because of the extreme weather impacts in North America and Europe caused by the eruption. The global summer temperature dropped 0.5°K below average, snows fell in midsummer and Europe experienced an unusually stormy winter. In the Northern Hemisphere, agricultural crops failed and much livestock died. It caused the worst famine of the century.[3]

During a 2004 excavation near Mount Tambora, a team of archaeologists discovered a civilization obliterated by the 1815 eruption.[2] It was kept intact deep beneath the 3 m pyroclastic deposits. Known as the Pompeii of the East, positions of the artifacts were still encapsulated as they were in 1815.

Geological formation

File:Tambora - the caldera.jpg
The caldera of Mt. Tambora. It is 6–7 km across and 600–700 m deep.

Mount Tambora is located on Sumbawa island, part of the Lesser Sunda Islands, which is in turn, part of the Sunda-Banda arc, a large string of volcanic islands that form the southern chain of the Indonesian archipelago. [4] Tambora itself forms its own peninsula on Sumbawa known as the Sanggar peninsula. Tambora lies 340 km north of the Java Trench system and 180–190 km above the upper surface of the active north-dipping subduction zone.

Tambora is a large stratovolcano with a 60 km diameter base. The lowermost portion contains deposits of interlayered sequences of lava and pyroclastic materials. Approximately 40% of the layers are represented in the 1–4 m thick lava flows. Within the upper section, the lava is interbedded with scoria, tuffs and pyroclastic flows and falls.[5] In addition to the huge caldera, there are parasitic cones, that have been named Tahe (877 m), Molo (602 m), Kadiendinae and Kubah (1648 m). There is also a crater inside the caldera known as Doro Api Toi.

A high volcanic cone was formed before the 1815 eruption that following the characteristic stratovolcano shape, with a central vent emitting lava frequently.[5] The lava then cascaded down a steep slope. Pyroclastic materials were produced by fragmentation during the flow and thick scoria beds were also produced. Intermittent explosive eruptions might have produced pumiceous pyroclastic flows.[5]

1815 eruption

Chronology of the eruption

The estimated volcanic ashfall regions during the 1815 eruption. The red areas show thickness of volcanic ashfall. The outermost region (1 cm thickness) reached Borneo and the Sulawesi islands.

Mount Tambora was long thought to be extinct, however, approximately three years before the 1815 eruption, the caldera began to rumble and generated a dark cloud.[6] On 5 April 1815, a moderately-sized eruption occurred with thunderous detonations heard as far away as Makassar on Sulawesi (380 km), Batavia on Java (1260 km) and Ternate on the Molucca Islands (1400 km). What was first thought to be the firing of guns, was heard on 10–11 April on Sumatra island (more than 2,600 km away).[7] On the morning of 6 April 1815, ash began to fall in East Java, with faint detonation sounds hear until the evening of the April 10.

At about 7 p.m. on 10 April 1815, the eruptions intensified,[6] as three columns of flame rose up and merged at height.[7] The whole mountain was turned into a flowing mass of "liquid fire".[7] Pumice stones of up to 20 cm in diameter started to rain down at approximately 8 p.m., followed by ash at around 9–10 p.m. Hot pyroclastic flows cascaded down the mountain to the sea on all sides of the peninsula, wiping out the village of Tambora. Loud explosions were heard until the next evening, 11 April. The ash veil had spread as far as West Java and South Sulawesi. A "nitrous" odor was noticeable in Batavia and heavy tephra-tinged rain finally receded between 11 and 17 April.[6]

The first explosions were heard on this Island in the evening of the 5th of April, they were noticed in every quarter, and continued at intervals until the following day. The noise was, in the first instance, almost universally attributed to distant cannon; so much so, that a detachment of troops were marched from Djocjocarta, in the expectation that a neighbouring post was attacked, and along the coast boats were in two instances dispatched in quest of a supposed ship in distress.

—Sir Raffles' memoir.[7]

The explosion is estimated to have been a scale 7 on the Volcanic Explosivity Index,[8] the only VEI 7 since AD 1400. It was roughly four times the energy of the 1883 Krakatoa eruption. An estimated 100 km² of pyroclastic trachyandesite was ejected, weighing approximately 1.4×1014 kg.[3] This left a caldera 6–7 km across and 600–700 m deep.[6] The density of fallen ash in Makassar was 636 kg/m².[9] Before the explosion Mount Tambora was approximately 4300 m (13,000 ft) high,[6] one of the tallest peaks in the Indonesian archipelago. After the explosion, it was only 2851 m (about 9,000 ft) high.[10]

The 1815 Tambora eruption is the largest observed eruption in recorded history (see Table I, for comparison).[6][3] The explosion was heard 2600 km away and ash fell at least 1300 km away.[6] Darkness enveloped an area as wide as 600 km away for up to 2 days. Pyroclastic flows spread at least 20 km from the summit.

Aftermath

All vegetation on nearby islands was destroyed. Uprooted trees mixed with pumice ash and washed into the sea, creating enormous rafts up to 5 km across. [6] One pumice raft was found in the Indian Ocean, near Calcutta on 1 and 3 October 1815.[3] Clouds of thick ash still covered the summit on April 23. Explosions ceased on July 15, although smoke emissions were still observed as late as 23 August. Flames and rumbling aftershocks were reported in August 1819, four years after the event.

On my trip towards the western part of the island, I passed through nearly the whole of Dompo and a considerable part of Bima. The extreme misery to which the inhabitants have been reduced is shocking to behold. There were still on the road side the remains of several corpses, and the marks of where many others had been interred: the villages almost entirely deserted and the houses fallen down, the surviving inhabitants having dispersed in search of food.
...
Since the eruption, a violent diarrhoea has prevailed in Bima, Dompo, and Sang’ir, which has carried off a great number of people. It is supposed by the natives to have been caused by drinking water which has been impregnated with ashes; and horses have also died, in great numbers, from a similar complaint.

—Lt. Philips, ordered by Sir Raffles to go to Sumbawa.[7]

A moderately-sized tsunami struck the shores of various islands in the Indonesian achipelago on 10 April, with a height of up to 4 m in Sanggar on the same island at around 10 p.m.[6] A tsunami of 1–2 m in height was reported in Besuki, East Java, before midnight and 2 m in height in the Molucca Islands.

The eruption column reached the stratosphere, an altitude of more than 43 km.[3] The coarser ash particles fell out 1–2 weeks after the eruptions, but the finer ash particles stayed in the atmosphere from a few months and up to a few years at an altitude of 10–30 km.[6] Longitudinal winds spread these fine particles around the globe, creating an optical phenomena. Between 28 June and 2 July 1815 and 3 September and 7 October 1815, prolonged and brilliantly colored sunsets and twilights were frequently seen in London, England.[6] Typically, the glow of the twilight sky appeared orange or red near the horizon and purple or pink above.

The estimated number of fatalities varies depending on the source. Zollinger (1855) put the number of deaths directly attributable to the eruption at 10,000, probably caused by pyroclastic flows, and a further 38,000 deaths due to starvation on Sumbawa island, and another 10,000 deaths due to disease and hunger on Lombok.[11] Petroeschevsky (1949) estimated about 48,000 and 44,000 people were killed on Sumbawa and Lombok, respectively.[12] Many modern authors use Petroeschevsky's figures, such as Stothers (1984), who cites 88,000 deaths in total.[6] However, Tanguy et al. (1998) claimed Petroeschevsky's sources to be unfounded and based on untraceable references. Tanguy revised the number solely based on two credible sources, i.e., Zollinger, who himself spent several months on Sumbawa after the eruption, and Raffles's notes.[7] He did however point out that there may have been additional victims on Bali and East Java because of famine and disease. His estimate was 11,000 deaths from direct volcanic effects and 49,000 by post-eruption famine and epidemic diseases.[13] Oppenheimer (2003) stated a modified number of at least 71,000 deaths in total, as seen in Table I below.[3]

Table I. Comparison of the selected volcanic eruptions.
Eruptions Year Column
height (km)		 Magnitude (kg) N. hemisphere
summer anomaly (°K)		 Fatalities
Taupo 181 51 7.7×1013 ? unlikely
Baitoushan 969 25 5.8×1013 ? ?
Kuwae 1452 ? > 8×1013 −0.5 ?
Huaynaputina 1600 46 2.1×1013 −0.8 ≈1400
Tambora 1815 43 1.4×1014 −0.5 > 71,000
Krakatau 1883 25 3.0×1013 −0.3 36,600
Santamaría 1902 34 2.2×1013 no anomaly 7,000–13,000
Katmai 1912 32 2.5×1013 −0.4 2
Mt. St. Helens 1980 19 7.1×1011 no anomaly 57
El Chichón 1982 32 3.0×1012 ? > 2,000
Nevado del Ruiz 1985 27 4.5×1010 no anomaly 23,000
Pinatubo 1991 34 1.3–1.8×1013 −0.5 1202
Source: Oppenheimer (2003).[3]

Global effects

See also: Year Without a Summer
Sulfate concentration in ice core from Central Greenland, dated by counting oxygen isotope seasonal variations. Prior to the 1815 eruption is an unknown eruption around 1810s. Source: Dai (1991).[14]

The 1815 eruption released sulfur into the stratosphere causing a global climate anomaly. Studies estimated the ejected sulfur mass during the eruption with different methods: the petrological method; an optical depth measurement based on anatomical observations; and the polar ice core sulfate concentration method from Greenland and Antartica. However, the figures vary depending on the method, ranging from 10 Tg S to 120 Tg S.[3]

In the spring and summer of 1816, a persistent dry fog was observed in the northeastern U.S. The fog reddened and dimmed the sunlight, such that sunspots were visible to the naked eye. Neither wind nor rainfall dispersed the "fog". It was identified as a stratospheric sulfate aerosol veil.[3] The summer of 1816 saw extreme weather conditions in the northern hemisphere, dubbed the Year Without a Summer. Average global temperatures decreased about 0.4–0.7°C,[6] enough to cause significant agricultural problems around the globe. On 4 June 1816, frosts were reported in Connecticut, and by the following day, most of New England was gripped by the cold front. On 6 June 1816, snow fell in Albany, New York, and Dennysville, Maine.[3] Such conditions occurred for at least three months and ruined most agricultural crops in North America. Canada experienced extreme cold during this summer. Snow 30 cm thick accumulated near Quebec City from 6 to 10 June 1816.

1816 was the second coldest year in the Northern Hemisphere since AD 1400 (1601 was the coldest following the 1600 Huaynaputina eruption in Peru).[8] The decade of the 1810s is the coldest on record; a result of Tambora's 1813 eruption and other suspected eruptions somewhere in the world in 1809 and 1810, as indicated from ice core data. The surface temperature anomaly during the summer of 1816, 1817 and 1818 were −0.51, −0.44 and −0.29°K, respectively.[8] As well as a cooler summer, parts of Europe experienced a stormier winter.

This pattern of climate anomaly has been blamed for the severity of a typhus epidemic in southeast Europe and the eastern Mediterranean between 1816 and 1819.[3] Much livestock died in New England during the winter of 1816–1817. The cool temperatures and heavy rains resulted in failed harvests in the British Isles. Families in Wales traveled long distances as refugees, begging for food. Famine was prevalent in north and southwest Ireland, following the failure of the wheat, oat and potato harvests. The crisis was severe in Germany where food prices rose sharply. Due to the unknown nature of the cause, demonstrations in front of grain markets and bakeries, followed by riots, arson and looting, took place in many European cities. It was the worst famine of the 19th century.[3]

Archaeological evidence

In summer 2004 a team from the University of Rhode Island, the University of North Carolina-Wilmington, and the Indonesian Directorate of Volcanology, led by Haraldur Sigurdsson, began an archaeological dig in Tambora.[2] Over six weeks, the team unearthed the first cultural evidence that had been smoethered by the Tambora eruption. The site is about 25 km west of the caldera, deep in the jungle, 5 km from the shore. The team had to cut through a deposit of volcanic pumice and ash 3 m thick.

File:Tambora excavation 1.JPG
The excavation site in Tambora. A team of archaeologists, led by Haraldur Sigurdsson, have unearthed the lost kingdom of Tambora.

The team used a ground-penetrating radar to firstly find a small house. The team excavated the house, where they found the remains of two adults, as well as bronze bowls, ceramic pots, iron tools and other artifacts. The design and decoration of the artifacts have similarities with artifacts from Vietnam and Cambodia.[2] After the artifacts were carbonized, it turned out to be charcoal from the heat of the magma, which is the evidence that an eruption had taken place. All the people, the house and their culture are still encapsulated as they were in 1815. Sigurdsson dubbed it the Pompeii of the East.[15][16] Based on the artifacts found, mainly bronze objects, the team concluded that the people were not poor. Historical evidence indicates that the Tamborans were famous in the East Indies for their honey, horses, sappan wood for producing red dye, and sandalwood used for incense, and medications.[2] The area was thought to be highly productive agriculturally.

The archaeological findings suggest that there was a type of civilization in Tambora, wiped out completely during the 1815 eruption. The Lost Kingdom of Tambora was then coined by media.[17][18] With this discovery, Sigurdsson intends to return to Tambora in 2007 to search for the rest of the villages, and hopefully to find a palace.[2]

See also

References

  1. ^ a b "Tambora". Global Volcanism Program. Smithsonian Institute. Retrieved 2006-10-07. {{cite web}}: Cite has empty unknown parameter: |1= (help)
  2. ^ a b c d e f "URI volcanologist discovers lost kingdom of Tambora" (Press release). University of Rhode Island. 2006-02-27. Retrieved 2006-10-06.
  3. ^ a b c d e f g h i j k l m Oppenheimer, Clive (2003). "Climatic, environmental and human consequences of the largest known historic eruption: Tambora volcano (Indonesia) 1815". Progress in Physical Geography. 27 (2): 230–259.
  4. ^ Foden, J. (1986). "The petrology of Tambora volcano, Indonesia: A model for the 1815 eruption". Journal of Volcanology and Geothermal Research. 27 (1–2): 1–41.
  5. ^ a b c "Geology of Tambora Volcano". Vulcanological Survey of Indonesia. Retrieved 2006-10-10.
  6. ^ a b c d e f g h i j k l m Stothers, Richard B. (1984). "The Great Tambora Eruption in 1815 and Its Aftermath". Science. 224 (4654): 1191–1198.
  7. ^ a b c d e f Raffles, S. 1830: Memoir of the life and public services of Sir Thomas Stamford Raffles, F.R.S. &c., particularly in the government of Java 1811–1816, and of Bencoolen and its dependencies 1817–1824: with details of the commerce and resources of the eastern archipelago, and selections from his correspondence. London: John Murray, cited by Oppenheimer (2003).
  8. ^ a b c Briffa, K.R. "Influence of volcanic eruptions on Northern Hemisphere summer temperatur over 600 years". Nature. 393: 450–455. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  9. ^ Stothers, Richard B. (2004). "Density of fallen ash after the eruption of Tambora in 1815". Journal of Volcanology and Geothermal Research. 134: 343–345.
  10. ^ Monk, K.A. (1996). The Ecology of Nusa Tenggara and Maluku. Hong Kong: Periplus Editions Ltd. pp. p. 60. ISBN 962-593-076-0. {{cite book}}: |pages= has extra text (help); Unknown parameter |coauthors= ignored (|author= suggested) (help)
  11. ^ Zollinger (1855): Besteigung des Vulkans Tamboro auf der Insel Sumbawa und Schiderung der Eruption desselben im Jahren 1815, Wintherthur: Zurcher and Fürber, Wurster and Co., cited by Oppenheimer (2003).
  12. ^ Petroeschevsky (1949): A contribution to the knowledge of the Gunung Tambora (Sumbawa). Tijdschrift van het K. Nederlandsch Aardrijkskundig Genootschap, Amsterdam Series 2 66, 688–703, cited by Oppenheimer (2003).
  13. ^ Tanguy, J.-C. (1998). "Victims from volcanic eruptions: a revised database". Bulletin of Volcanology. 60 (2): 137–144. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  14. ^ Dai, J. (1991). "Ice core evidence for an explosive tropical volcanic eruption six years preceding Tambora". Journal of Geophysical Research (Atmospheres). 96: 17, 361–17, 366. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  15. ^ "'Pompeii of the East' discovered". BBC NEWS. 28 February 2006. Retrieved 2006-10-09.
  16. ^ "Indonesian Volcano Site Reveals `Pompeii of the East' (Update1)". Bloomberg Asia. 28 February 2006. Retrieved 2006-10-09.
  17. ^ ""Lost Kingdom" Discovered on Volcanic Island in Indonesia". National Geographic. 27 February 2006. Retrieved 2006-10-09.
  18. ^ "'Lost kingdom' springs from the ashes". International Herarld Tribune. 1 March 2006. Retrieved 2006-10-09.

Further reading

  • Henry & Elizabeth Stommel: Volcano Weather: The Story of 1816, the Year without a Summer, Newport RI 1983
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