
Volcanoes are one of the most dramatic spectacles on the planet. Red hot lava can be thrown hundreds of feet into the air, or flow down the mountainside like rivers of flame.However, a volcanic eruption is not something that many of us will actually witness – not in person. Although millions of people do live in volcanic regions, for many more of us it seems like something distant and a little exotic. We don’t think that it’s something we actually have to worry about.
But the damage wreaked by a volcano can reach far further than its lava flows. A big enough volcanic eruption can change the world.

“I had a dream, which was not all a dream.
The bright sun was extinguish’d, and the skies
Did wander darkling in the eternal space,
Rayless, and pathless, and the icy earth
Swung blind and blackening in the moonless air.
Morn came and went – and came, and brought no day,
And men forgot their passions in the dread
Of this their desolation; and all hearts
Were chill’d into a selfish prayer for light.”
The poem “Darkness” by Lord Byron is incredibly dramatic and apocalyptic, but it isn’t a work of pure imagination. In the summer of 1816, on the shores of Lake Geneva, Byron witnessed days of strange darkness; and on at least one such day, the sun simply couldn’t be seen at all. What he didn’t know was that the darkness he saw was the result of something that had happened over a year before, and many, many miles away.
Mount Tambora lies on the island of Sumbawa in the Indonesian archipelago, less than 600 miles south of the Equator. At the beginning of 1815, it stood more than 4,300 metres or 14,100 feet tall.
This changed in April of that year. Tambora was – and still is – a stratavolcano, and although it had been dormant for centuries, it was waking up. It had, for some time, been emitting ominous rumbles and belches.
The eruption began on the evening of the 5th of April. With an enormous sound like a thunderclap, the mountain emitted a column of fire that burned for three hours.
Then, as quickly as it had begun, it seemed to be over.
It wasn’t.
On the evening of the tenth, the mountain awoke again. This time, the summit exploded in three columns of fire, throwing a huge amount of ash and pulverised rock into the air. Lava flowed down the mountainside, and a rain of fire, ash, and pumice stones, some described as big as two fists, fell all around.
A native poet from Bima described the scene, just as Byron would later from his villa in Geneva.
The mountain reverberated around us
As torrents of water mixed with ash fell from the sky.
Children screamed and wept, and their mothers, too,
Believing the world had been turned to burning ash.
In the immediate area, the devastation was extensive. The villages on the Sanggar peninsula were no more. On the north and western slopes, around ten thousand people were estimated to have been consumed by fire, winds and ash.
As pyroclastic flows raced across the island and reached the sea, more explosions followed. Steam and ash clouds rose wherever they met. Huge tsunami waves hit the coast, washing away rice fields and surviving villages, and then, as the volcanic cone of Mount Tambora collapsed, the land beneath survivors’ feet shook and sank.
This was what is called a Plinian eruption, named after Pliny the Younger because of his account of the explosive eruption of Mount Vesuvius.
And this wasn’t the end of the horror for the islanders. The following days were darkened by the hovering ash cloud, and those who survived found little to eat or drink; wells had been poisoned by ash, and all the crops destroyed. Thousands more would die of sickness and starvation.

On the 11th of April, the captain of the Benares, an East India Company ship, described what they saw sailing nearby.
“By noon, the light that had remained in the eastern part of the horizon disappeared, and complete darkness had covered the face of day… The darkness was so profound throughout the remainder of the day, that I never saw anything equal to it in the darkest night; it was impossible to see your hand when held up close to the eye.”
When they finally found daylight again, their ship looked very different.
“The masts, rigging decks and every part being covered with falling matter; it had the appearance of a calcined pumice stone, nearly the colour of wood ashes; it lay in heaps of a foot in depth in many parts of the deck, and I am convinced several tons weight were thrown overboard.”
Darkness fell upon an area some 600 kilometres in radius, and lasted for two days. Sumbawa and the neighbouring island Lombok were devastated; on Bali ash covered the ground to a depth of half a metre. With no crops left, starvation loomed, and thousands tried to sell themselves or their children into slavery, just to get a little rice to eat.
But even this last resort was not available to all. Stamford Raffles, the British governor of Java, had made the slave trade illegal in Batavia (now called Djakarta). His progressive action had unforeseen consequences. Parents who couldn’t feed their children, and who couldn’t bear to watch them suffer slow starvation, left their lifeless bodies on the beaches.
What made the eruption of Mount Tambora different to other volcanic events was its sheer violence, First the plinian jet, and then the secondary ash clouds which were generated by the pyroclastic flows hitting the ocean, threw huge amounts of volcanic matter high up into the stratosphere, some 40 kilometres up.When I say huge, I mean really, seriously huge; after the eruption, Mount Tambora stood some 1,449 metres shorter than before, and had a giant caldera at the top six kilometres wide. It’s been compared to taking all of the topsoil in Illinois and Texas and throwing it into the sky.

The heavier bits came straight back down again, causing the heavy ash rain that fell across the Sanggar peninsula. But there was a lot of lighter stuff in the cloud, too. Sulfur and fluorine gases, and very fine ash particles which didn’t have enough weight to carry them down to earth right away. They had blown so far up into the atmosphere that they were above the rain-carrying clouds which might otherwise have washed them down.
These lighter particles didn’t just hang in the air above the mountain, though. Carried by the winds, they spread and spread. Because Tambora was so close to the equator, and because of the way the trade winds swirl around the globe, they went pretty much everywhere. Evidence of this cloud has been found in the ice at both poles.
Once wrapped around the entire world, this cloud of dust reflected some of the warming rays of the sun back into space, and the Earth cooled. It took some three years for the cloud to finally disperse, but its effects would be most strongly felt in 1816: The Year Without A Summer.
The recurring refrain throughout that year was that no such weather could be recalled by even the oldest living inhabitants of any given area. It was difficult to be more specific, as it was not yet common for weather data to be routinely recorded; meteorology was in its infancy. The records we do have come mainly from the diaries of gentlemen scientists; clergymen and the like, who seem to have kept their data out of sheer curiosity. One such was a Scottish man named George Mackenzie, who carefully recorded how cloudy the skies over the British Isles were between 1803 and 1821. In 1816, he recorded that there were no clear days at all.
That might sound like ordinary British weather, but for comparison, between 1803 and 1810 he recorded an average of more than twenty clear summer days per year. And we’re not just talking about disappointing weather for a picnic; the lack of sunshine had a devastating impact.
The effects of Tambora’s eruption were widespread, but they were not uniform in nature. While some parts of the world, such as Britain and Western Europe, were battered and deluged by storms, others suffered a seemingly endless drought.
These varying extremes, however, had a similar effect on agriculture. Yields fell dramatically; crops withered or rotted in the fields, people rioted over bread as the prices rose far out of the reach of ordinary labourers. With no harvest in sight, many resorted to desperate measures. Some fled, becoming refugees and wandering in search of somewhere that might take them in. Others scavenged for what little they could find.
A priest in Glaris, Switzerland, wrote, “It is terrifying to see these walking skeletons devour the most repulsive foods with such avidity: the corpses of livestock, stinking nettles – and to watch them fight with animals over scraps.”

In Ireland, Tambora could have taught a valuable lesson, but it was sadly ignored. An official account given in Parliament after the fact by Charles Grant, Chief Secretary for Ireland, began:
“In the years 1816 and 1817, the state of the weather was so moist and wet, that the lower orders in Ireland were almost deprived of fuel wherewith to dry themselves, and of food whereon to subsist. They were obliged to feed on esculant plants such as mustard-seed, nettles, potato-tops and potato-stalks – a diet which brought on a debility of body and encouraged the disease more than anything else could have done.”
The disease in question was typhus, and its spread was causatively linked to the deprivations caused by the weather. Temperatures had fallen and rainfall increased to such a degree that crops were literally drowned. In Drogheda, ducks were seen swimming in a field that was supposed to be growing oats and potatoes.
The poor tenants of these lands had little relief, because their English landlords were far away, often in London, and simply didn’t see their suffering. Left with nothing, they succumbed to the cold and damp, to their starvation diet, and wandered the countryside in rags trying to find a town that would take them in. All too often, they found the doors barred.
The failure of the harvests here could have led to the introduction of measures to prevent such a famine in future, but it didn’t. A little over twenty years later, Ireland would suffer again in the Great Famine, which drove many of those who didn’t starve to death to flee to America.
The States was not exempt from the effects of Tambora’s eruption either. It became known as the year “Eighteen Hundred and Froze To Death” because the climate was so harsh. Unseasonal frosts in June, July and August put paid to any hopes of a decent harvest, and even the cotton harvest in the South was affected.
This drove many to abandon their homes and head West, for the new promised land of the frontier. Some made their way on foot, pushing all their worldly possessions in a handcart, in a desperate hope of starting a new life in new fertile lands. And the West was successful, sending crops back East to those in need and exporting them elsewhere at a great profit. However, this success would be short-lived. Once Tambora’s dust cleared, and European harvests recovered, the artificially inflated prices of American crops collapsed, leading to the country’s first Depression.
The Chinese island of Hainan saw snow falling in the summer of 1815, then experienced such a severe winter that more than half of the forests there died. Summer frosts in Shanxi in 1817 killed the crops and drove many to flee the province. And, in the south-west province of Yunnan,known as the Land of Eternal Spring for its mild climate, bitter rains and plunging temperatures meant three growing seasons in a row failed. Again, it inspired a poetry of devastation, this time from the pen of Li Yuyang.
“The clouds like a dragon’s breath on the mountains,Winds howl, circling and swirling,The Rain God shakes the stars, and the rainBeats down on the world. An earthquake of rain.Water spilling from the eaves deafens me.People rush from falling houses in their thousandsAnd tens of thousands, for the work of the rainIs worse than the work of thieves. Bricks crack. Walls fall.In an instant, the house is gone. My child catches my coatAnd cries out. I am running in the muddy road, thenBack to rescue my money and grains from the ruins.What else to do? My loved ones must eat.There are no words for the bitterness ofAn empty September. The flood-drowned fieldsHarvest three grains for every ten of a good year.
And from these three grains? Meals and clothes till next September.”
And just as the people living in the shadow of Tambora had resorted to desperate measures, so did the people of Yunnan province. Another of Li Yuyang’s poems:
“300 copper coins for a bag of grain300 copper coins for three days of lifeWhere can the poor people find such money?They barter their sons and daughters on the streets.Still they know the price of a sonIs not enough to pay for their hunger.
And yet to watch him die is worse.”
Many of the farmers in Yunnan gradually turned to another crop; one that became as good as money, because of its export value, and which would grow in more inhospitable conditions than rice. But this crop wasn’t grown for food. They began growing opium poppies, becoming a centre for a booming illicit drug trade.

In India, the monsoon rains failed to arrive as expected; May, June and July were cripplingly dry. Then, in late August, the drought finally broke – bringing with it hundred-year floods and a different kind of devastation. Disease was common, and the banks of the River Ganges were covered with the dead and the dying. The following year was also bad; this time the monsoon came early, and an epidemic of cholera followed quickly in its wake, boosted by the alternation of drought and flood.
An English traveller, James Statham, described the horrors he saw there.
“The dead and dying are all huddled together in a confused mass, and several fires are blazing at the same time, consuming the bodies of the more rich and noble, who have just died, whilst the poor creatures who are expiring feel certain that in a few minutes their bodies must share the same fate, or be hurled into the flowing stream, to become the prey of waiting alligators, or, what is worse, to be left on the beach, a prey to jackals and vultures, which infest the spot. Fresh arrivals every hour multiply the misery, as groans and cries increase…”
Tambora’s eruption also acted as the trigger for another disaster – one that wouldn’t actually happen for some years. A memo from a Royal Society council meeting in November 1817 attributes these words to Sir Joseph Banks:
“A considerable change of climate inexplicable at present to us must have taken place in the Circumpolar Regions, by which the severity of the cold that has for centuries past enclosed the seas in the high northern latitudes in an impenetrable barrier of ice has been, during the last two years, greatly abated. This affords ample proof that new sources of warmth have been opened, and gives us leave to hope that the Arctic Seas may at this time be more accessible than they have been for centuries past, and that discoveries may now be made in them, not only interesting to the advancement of science, but also to the future intercourse of mankind and the commerce of distant nations.”
In short, the Arctic ice was melting, and hopes of finding a northwest passage through to the Pacific – bypassing the arduous route around South America – had arisen. A new wave of Arctic exploration began on that basis, and would lead, in time, to the disastrous Franklin expedition of 1845, when 128 men embarked on a mission to find that northwestern route – and not a single man returned. If you’re interested in that, you might want to check out The Terror, a new AMC television series based on the Dan Simmons novel by the same name, which tells a fictionalised account of that expedition.

Amidst all this disaster and devastation, though, there was also creation and beauty. Mount Tambora’s clouds of ash painted the sunset skies around the world with such vivid colours that many artists were inspired to attempt to record them. J.M.W. Turner’s landscapes are a prime example.
And to return to Geneva, where I began with Lord Byron, he was not the only one inspired by those dark and doom-laden stormy nights. On one famous occasion, he and his companions, trapped inside by the weather, turned to telling ghost stories, and then to creating their own. From the tales they spun on that night, John Polidori created The Vampyr, which in turn served as inspiration for Bram Stoker’s Dracula, and the young Mary Godwin, later Mary Shelley, created Frankenstein.

Thanks this episode go to:
I’d like to say a special thank you to Patreon supporter Mish Liddle, and to all of you for listening and reading.
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Sources and Further Reading:
Wikipedia: 1815 Eruption of Mount Tambora
Wikipedia: Year Without a Summer
Tambora: The Eruption That Changed The World – Gillen D’arcy Wood
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