Lessons of Tambora ignored—200 years on from the world’s greatest modern eruption

Lessons of Tambora ignored—200 years on from the world’s greatest modern eruption

Amidst commemorations of the Gallipoli landing, writes ANTHONY REID,the anniversary of another, perhaps more significant disaster for humanity, slipped by largely unnoticed.

Australia is spending many millions commemorating in April 2015 the centenary of one disaster. The Gallipoli landing symbolises for Australians one of the greatest man-made catastrophes. We have almost completely ignored the bicentenary of another disaster more important for the planet and perhaps even for humanity—the eruption on 10 April 1815 of Tambora Mountain in southeastern Indonesia. Perhaps our own suicidal folly as a species is more fascinating to us than the staccato rhythm of an environment we cannot control.

Tambora Mountain (pictured), dominating a narrow peninsular of the amoeba-shaped island of Sumbawa midway between Jakarta and Darwin, was one of the highest in our region until 1815. It then exploded, sending an estimated 160 cubic kilometres of pyroclastic material into the atmosphere, weighing about 140 billion tons.

Tambora Mountain: eruption killed thousands.

The explosion would certainly have been heard by the few inhabitants of northern Australia, since there were reports from Jakarta and more distant Sumatra. The pyroclastic material, however, was carried primarily westward by the prevailing winds, dropping mostly on the land and waters of Indonesia before carrying an ash cloud several times around the world.

Those directly killed by the explosion of gases and lava flows were mainly on the Tambora Peninsula of Sumbawa itself, where the explosion killed virtually everybody—thought to be 11,000 people. Speakers of the Tambora language, a wordlist of which had been collected by Raffles before the eruption, were wiped out, eliminating what is now understood to have been by far the most westerly survival of a Papuan-type (non-Austronesian) language.

At least 10 times as many died slowly of hunger and disease in the remainder of Sumbawa Island and in Lombok and Bali to its west, as agriculture was destroyed by ash deposits and lack of sunlight. Harvests in Bali (the best-documented) were drastically affected for the next four years. The devastated population was then assailed by infestations of rats which consumed much of the little food left.

Hunger in Bali

Bali in good times was a major exporter of rice, but for two decades after 1815 its major export was slaves desperate to find food elsewhere. A Dutch visitor to Bali in 1818 counted 34 corpses lying beside the 25 km track between Badung and Gianyar, having presumably failed to survive the desperate walk in search of food. Only after 10–15 years of misery did the ecological curse turn again to a blessing as the nutrients in the ash were absorbed to fertilise Bali’s soils.

Those who died of hunger in this way were not reported as victims of the volcano, any more than those who died on the other side of the world as the ash cloud darkened skies and lowered temperatures in Europe and America.

The dearth of population figures anywhere in Indonesia before 1820 vitiates demographic attempts to calculate the loss—though the earliest censuses of Java showed a very anomalous absence of people in the easternmost salient of that island. Using population figures to estimate the later, smaller eruptions of Krakatoa (1883) and Kelut (1919), however, shows a ‘missing’ agricultural population of a little under 100,000 from the former and well over that figure in the latter.
Why did Tambora remain so little known, despite ejecting at least four times as much material as Krakatau, the second biggest eruption of the modern era?

The explosion is now understood to have lowered global temperatures by about a degree, and produced in 1816 the ‘year without summer’ in Western Europe and New England.

Krakatau was much closer to the European communication centres of Singapore and Batavia (Jakarta), while the introduction of the telegraph in mid-century had shrunk the world dramatically. Newspaper readers in Europe eagerly consumed descriptions and images of the Krakatau eruption, and some even linked it to strange weather conditions in Europe.

Tambora’s eruption was hardly reported in Europe. Only as climatologists, geophysicists and historians in the last 30 years worked out the relative scale of past eruptions through physical measurement of craters and ash deposit in ice cores in the polar caps, and came to understand the impact of volcanic mega-eruptions on climate, were the dots joined to point to Tambora.

The explosion is now understood to have lowered global temperatures by about a degree, and produced in 1816 the ‘year without summer’ in Western Europe and New England, with frosts and snowfalls in June and July. There were consequent famines in many parts of Europe, western China and North America.

The crisis was one of the triggers for the migration westward of New England farmers rendered desperate by the failure of their 1816 crops. On the mildly positive side, J.M.W. Turner’s darkly yellow landscapes have been attributed to the Tambora eruption. The ‘incessant rainfall’ of June 1816 forced Mary Shelley to stay indoors with her friends on a Swiss holiday, and to write her classic Frankenstein.

Risk to humanity

Although our Eurocentric memory continues better-informed about Vesuvius and Etna, the science now understands that it is the volcanic arc to the north of Australia that poses the greatest risk to humanity. Homo sapiens came closest to being wiped out, it is now believed, by the massive explosion in Sumatra that left the crater that is now Lake Toba, 74,000 years ago.

A fuller appreciation of the magnitude of Tambora’s effects 200 years ago would be likely to have healthier effects on our national priorities than the obsession with military anniversaries. It might focus attention on the certain need to prepare for future mega-eruptions on the ‘ring of fire’ to Australia’s north, rather than feeding the insecurities that repeatedly send us off to fight other people’s wars on the false premise of an ‘insurance policy’.

It was another, smaller Indonesian volcanic eruption, Galunggang (West Java) in 1982, which first alerted the airline industry to the danger of volcanic ash to passenger jets, two of which were forced to make emergency landings after engine failures caused by the ash. A mega-eruption on the scale of Tambora or Krakatau repeated in our age of mass air travel would have unimaginable consequences for global communication, isolating Australia for months if not years.
There were two such mega-eruptions in the 19th century, but none of equal size in the 20th. Science has more recently identified at least equally large eruptions in the volcanic arc to Australia’s north, as the cause of earlier climatic disturbance and famine around the world. Kuwae in Vanuatu in 1452, and Rinjani in Lombok (just west of Sumbawa) in 1257 are now known to have been of equal size, and work is ongoing to identify other volcanic sources of climatic disruption in the 16th and 17th centuries.

All of this suggests that the last century and a half has been unusually fortunate for our region, but that another mega-disaster of this kind should be expected in the century ahead. We may have failed to learn the lessons of Gallipoli, but 200 years should be enough to learn the lessons of Tambora, and devote more of our defence budget to preparing for tectonic catastrophe.

Australian troops at Anzac Cove.

Anthony Reid is an emeritus professor in the College of Asia and the Pacific, Australian National University.

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