VolcanicDegassing

Indonesia

The great eruption of Tambora, April 1815

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Map of the Sanggar peninsula, on the island of Sumbawa, Indonesia, and the crater of Tambora. From Heinrich Zollinger’s 1847 expedition to the crater, published in 1855. From University of Oxford, Bodleian Library Collection.

April 2015 marks the 200th anniversary of the great eruption of Tambora, on Sumbawa island, Indonesia. This eruption is the largest known explosive eruption for at least the past 500 years, and the most destructive in terms of lives lost, even though the precise scale of the eruption remains uncertain. The Tambora eruption is also one of the largest known natural perturbations to the climate system of the past few hundred years – having left a clear sulphuric acid ‘fingerprint’ in ice cores around the world, and evidence for a strong causal link to the ‘year without a summer‘ of 1816, and global stories of inclement or unusual weather patterns, crop failures and famine.

Much of what we do know about the eruption and its local consequences is down to the efforts of two sets of people: Stamford and Sophia Raffles; and Heinrich Zollinger. In 1815, Thomas Stamford Raffles was temporary governor of Java; the British having invaded in 1811. Shortly after the eruption of Tambora, he gathered reports from people in areas affected by the eruption, and put these together in an ‘account of the eruption of the Tomboro mountain‘, which was published first in 1816 by the Batavian Society for Arts and Sciences, and later published posthumously by his wife, Lady Sophia Raffles, in her biography of his life and works (Raffles, 1830).

There is a considerable scientific literature (see references below) which has documented the main phases of the eruption, which began in earnest on April 5, 1815, and built to an eruptive climax on 10 – 11 April 1815. It is thought that the volcano had been rumbling for some time prior to this, perhaps as early as 1812; and some of the contemporary records collected by Raffles suggest that the first ashy explosions may have begun by about April 1, 1815. An extract from a letter from Banyuwangi, Java, 400 km west of the Sanggar peninsula, describes this stage of the activity:

At ten PM of the first of April we heard a noise resembling a cannonade, which lasted at intervals till nine o’clock next day; it continued at times loud, at others resembling distant thunder; but on the night of the 10th, the explosions became truly tremendous. On the morning of the 3rd April, ashes began to fall like fine snow; and in the course of the day they were half-an-inch deep on the ground. From that time till the 11th the air was continuously impregnated with them to such a degree that it was unpleasant to stir out of doors. On the morning of the 11th, the opposite shore of Bali was completely obscured in a dense cloud, which gradually approached the Java shore and was dreary and terrific.

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Heinrich Zollinger’s map of the inferred distribution of volcanic ash that fell across Indonesia following the eruption of Tambora in 1815. This may be the first example of an ‘isopach’ map of ash fallout from any volcanic eruption. From University of Oxford, Bodleian Library Collection.

The climactic phase of the eruption was very clearly described in an account by the Rajah of Sanggar, given to Lieutenant Owen Phillips, who had been sent to deliver rice for relief, and to collect information on the local effects of the eruption. ‘about seven PM on the 10th of April, three distinct columns of flame burst forth near the top of Tomboro mountain.. and after ascending separately to a very great height, their caps united in the air. In a short time the whole mountain next Sangar appeared like a body of liquid fire extending itself in every direction

In the main phase of the eruption, pyroclastic flows laid waste to much of the Sanggar peninsula, causing huge loss of life; and leaving a great collapse crater (caldera) where there had once been a tall volcanic peak.

Heinrich Zollinger was Swiss botanist, who moved to Java in 1841. In 1847, he led an expedition to Tambora and was the first scientist to climb to the crater rim since the eruption. In a short monograph, published in 1855, Zollinger describes his ascent of the volcano, documents the severe local impacts of the eruption, and details the numbers of people on Sumbawa affected by the eruption:

Location Killed in the eruption Died of hunger, or illness Emigrated
Papekat 2000
Tambora 6000
Sangar 1100 825 275
Dompo 1000 4000 3000
Sumbawa 18000 18000
Bima 15000 15000
Total 10100 37825 36725

Zollinger also estimated that at least 10,000 also died of starvation and illness on the neighbouring island of Lombok; and current estimates for the scale of the calamity are that around 60,000 people died in the region.

The bicentennial of the eruption of Tambora is a sobering moment to reflect on the challenges that a future eruption of this scale would pose, whether it were to occur in Indonesia, or elsewhere. Our present-day capacity to measure volcanic unrest should certainly be sufficient for a future event of this scale to be detected before the start of an eruption; but would we be able to identify the potential scale of the eruption, or its impact, in advance? Much remains to be done to prepare for and mitigate against the local, regional and global consequences of a repeat of an explosive eruption of this scale – and we still have more to learn by taking a forensic  look back at past events.

References

Auker, MR et al., 2013, A statistical analysis of the global historical volcanic fatality records. Journal of Applied Volcanology 2: 2

Oppenheimer, C., 2003, Climatic, environmental and human consequences of the largest known historical eruption: Tambora volcano, Indonesia, 1815. Progress in Physical Geography 27, 230-259.

Raffles, S, 1816, Narrative of the Effects of the Eruption from the Tomboro Mountain, in the Island of Sumbawa on the 11th and 12th of April 1815, Verhandelingen van het Bataviaasch Genootschap van Kunsten en Wetenschappen [via Google Books]

Raffles, S, 1830. Account of the eruption from the Tomboro Mountain, pp 241-250; in Memoir of the life and public service 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.

Self, S, et al., 1984, Volcanological study of the great Tambora eruption of 1815. Geology 12, 659-663.

Sigurdsson, H. and Carey SN, 1989, Plinian and co-ignimbrite tephra fall from the 1815 eruption of Tambora volcano. Bulletin of Volcanology 51, 243-270.

Stommel, H and Stommel, E, 1983, Volcano weather: the story of 1816, the year without a summer. Seven Seas Press, Newport, Rhode Island.

Stothers, R.B., 1984, The great Tambora eruption in 1815 and its aftermath. Science 224, 1191-1198.

Zollinger, H., Besteigung des Vulkanes Tambora auf der Insel Sumbawa, und schilderung der Erupzion desselben im Jahr 1815. [Ascent of Mount Tambora volcano on the island of Sumbawa, and detailing the eruption of the same in the year 1815]

Links to online resources, and further reading

Bill McGuire ‘Are we ready for the next volcanic catastrophe?’The Guardian, 28 March 2015.

Gillen Darcy Wood ‘1816, The Year without a Summer’ BRANCH: Britain, Representation and Nineteenth-Century History. Ed. Dino Franco Felluga. Extension of Romanticism and Victorianism on the Net.

Haraldur Sigurdsson ‘Tambora: the greatest explosion in history’, a National Geographic photo gallery.

Tambora bicentennial – collection of papers in Nature Geoscience (Paywalled)

Gillen D’Arcy Wood’s Tambora; and an entertaining book review by Simon Winchester, author of ‘Krakatoa, the Day the World Exploded’

Anja Schmidt, Kirsten Fristad, Linda Elkins-Tanton (eds), Volcanism and Global Environmental Change, Cambridge University Press, 2015.

Update on the eruption of Gunung Kelud

Area – thickness plot for Kelut fall deposits.  1990 data from Bourdier et al., 1997 (not all proximal data are plotted).

Preliminary ash thickness – isopach area plot for the February 2014 Kelut eruption. 1990 data from Bourdier et al., 1997 (not all proximal data are plotted).

The dramatic eruption of Gunung Kelud, or Kelut, led to a flurry of images of ash appearing on many social media platforms, including Flickr, Instagram and Twitter. As an experiment in a volcanology class, we sought out images that we could locate on a map, and by classifying the ash deposits as ‘light’, ‘moderate’ or ‘heavy’, generated a very rough contour map of the ash fallout from the eruption. The data show, very crudely, an exponential decay of ash thickness away from the volcano, and allows us to estimate the amount of ash deposited across Java during the eruption. Our current estimate is that the eruption may have deposited the equivalent of 0.2 – 0.3 cubic km of magma across the region. There are considerable uncertainties in this value, but it does confirm that the 2014 eruption was indeed substantial, rating as a Magnitude 4 (VEI 4) event.

Fuller details can be found in a preliminary report: Ash fallout from the 2014 Kelut eruption.

Friday Field Photos: Eruptions at Lokon-Empung volcano, Indonesia

Friday Field Photos: Eruptions at Lokon-Empung volcano, Indonesia

This week I am at a workshop near the twin-peaked volcano Lokon-Empung, in Sulawesi, Indonesia. True to form (it is the most active volcano in Sulawesi), Lokon has been rather active, with fairly frequent small explosions forming some small but dramatic ash plumes. The active vent is not at the summits of either Lokon, or Empung, but instead at the crater called Tompualan, which lies in the saddle between the two peaks. Lokon-Empung had been quiet since July 2013, but re-awoke with a large explosion on the morning of September 9th. Below, I show a series of photos of explosions on September 10th and 12th, taken from Tomohon, about 5 km away. These explosions are moderately energetic, but short-lived – lasting at the most just a few minutes. Volcanoes like Lokon may have hundreds of explosions of this scale every year during their active phases.

Lokon Empung volcano.

View of Lokon (left peak) and Empung (right peak). The active crater of Tompualan lies in between the two. 10 September , 6.01 am local time.

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Early morning ash plume, from an explosion in Tompualan crater, Lokon-Empung volcano. September 10th, 6.19 am local time. The explosion began at 6.15 am. The volcano observatory estimated the peak plume height at 1 km above the vent.

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10 September, 6.35 am local time. The short explosion is now over, and the ash plume is dissipating.

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Larger explosion at Tompualan crater on 10 September at 6.59 am local time. The explosion started shortly before this point, and the volcano observatory estimated the eventual plume height to be 2.4 km.

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Tompualan crater, Mt. Lokon-Empung, 10 September, 7.00 am local time. The plume continues to grow.

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The plume from Lokon-Empuang is now reaching its peak height, as it reaches the cloud base. 10 September, 7.01 am local time.

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Mt Lokon-Empung, 10 September, 7.10 am. The main explosion has now ceased, and the plume is beginning to decay as ash particles fall out, and the plume is dispersed by winds.

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Mt Lokon-Empung, 12 September. Fume from the Tompualan crater is barely visible against the background meteorological cloud.

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The early stages of a small explosion from Lokon-Empung, 12 September, 12.37 local time.

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Continued expansion of the ash plume at Lokon-Empung, 12 September, 12.38 local time.

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The ash plume continuing to grow, September 12, 12.38 local time.

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The explosion has ceased, and the ash plume is beginning to disperse. 12 September, 12.40 local time.

Continued ash venting, 13 September, 7.17 am local time.

Further reading

The Volcanological Survey of Indonesia has a website that documents the current state of activity at its many volcanoes.  Many of the local observatories have webcams – such as the one at Kakaskasen Volcano Observatory (KKVO) near Lokon.

Two recent blogs have documented the context of this volcanism, and the ongoing activity at Lokon:

Culture Volcan – journal d’un volcanophile.  Culture Volcan has also posted a nice time-lapse video of the 12 September activity on YouTube, based on the webcam from KKVO.

Joe Bauwen’s Sciency Thoughts blog