Tambora, the lost summer and the hobby horse

Morn came and went – and came, and brought no day
Lord Byron, Darkness, 1816

The world has changed. It is not something we normally notice – change is slow and memory surprisingly selective. Nothing has altered but everything’s changed, as the song says, paraphrasing Jean-Paul Sartre. We have little idea of how our parents really grew up – their lives were very different from ours. People were reading more, in the absence of in-house screen entertainment. Looking at books written in the 19th century, you’ll find that the writing often was complex. And these complex writings were read by ordinary people who nowadays might read a tabloid. (Spending too much time in The Sun can be bad for you.) In those days, Dostoyevski mesmerized. Nowadays it takes effort to read him – the written word has become simpler but he hasn’t changed. Hygiene was another major difference. The world (and houses and people) of old were a lot smellier. But perhaps the most significant difference is transport. Travel was slow, and even 50 kilometers away was foreign. Long distance holidays did not exist. Modern transport has changed our society beyond their imagination. Now we have moved beyond even that: the worldwide on-line community which our children inhabit would have been alien to our parents. But this community grew out of a transport revolution.

Quote from De Medicine Equorum, Jordanus Ruffus, 13th century

Before this revolution, just two centuries ago, life was lived in the slow lane. There were no cars, trains, or planes, and ships were slow beyond believe. Carriages provided wheeled transport, but they required pulling power. This was invariably provided by horses. But horse-and-carriage had limits. The roads were often not optimal for them. The wheels would create deep ruts which could make them near impassable wherever maintenance faltered. And even paved roads were not always optimal. Take for instance the famous Roman roads which were the glue of an empire. They were straight as an arrow, completely oblivious to the topography of the land. The ascends were therefore often steep, far too steep for a horse and carriage. Roman roads were made for walking, excellent for mass transport of armies but unsuitable for cargo.

The biggest problem about transport, though, was cost. A horse was very expensive. One draft horse could be as much as the annual income of an average farmer. (A war horse would be ten times as much or more but was less useful to the average peasant. Being a knight required wealth.) Rent-a-horse or share-a-horse was often the only option.

But everything changed in the early 19th century. And it involved a volcano.


The trouble began on April 5, 1815, when distant cannon fire was heard. Indonesia had become British in 1811, to prevent the French from taking over; Sir Raffles, the governor in Java, send a regiment of troops to investigate the attack. No enemy could be found. The next day, some ash was falling and the sun appeared as in a fog. It was evident that a volcano had erupted, but no one knew which one. Earthquakes were felt in the east of Java on the 11th, and the Sun darkened further: visibility was reduced to 300 meters. On April 12, the morning in Batavia was late. People woke up in darkness, unsure of the time, and breakfast was held in candle light. The darkness began to lift a little by 10am, by which time the first birds finally began to chirp. The sun became faintly visible only by the end of the day.

Tambora. Once this was one of the tallest mountains of Indonesia.

The unknown culprit was more than 500 km away, to the east. Tambora had only recently revealed itself to be volcanic. Three years earlier, people living closer to the events first noted that Tambora had acquired a summit cloud which the wind would not disperse. Later, occasional thunder was heard. In 1814, a ship which passed close to the coast reported significant activity at the mountain. A cloud of ashes blackened one side of the horizon, looking to the world like a threatening tropical squall. In fact, it was mistaken for one and the commander of the ship took in sail, and prepared to encounter it. On approach, the real nature of the phenomenon became apparent, and ashes even fell on the deck. The stories finally reached Batavia, and a Mr. Israel was dispatched to investigate. Mr. Israel reached Tambora on 9 April 1815. He did not survive.

The main phase of the eruption started on April 5, 1815, with violent explosions. The first full-blown explosions had in fact already been on April 1, but this news never reached Java. The big event came on the evening of April 10, a day after the arrival of Mr Israel. It changed what had been a VEI-5 event into the third (or even second) largest eruption of the millennium. It caused a day of darkness 500 km away; nearer Tambora complete darkness lasted for several days, and the air didn’t fully clear until the monsoon rains resumed on the 17th. Some activity continued until July 15 but this was minor compared to the two major eruptions of April 5 and 10. The mountain had been as high as 4 km before the events (the actual height is not recorded); the two explosions reduced this to less than 3 km afterwards. The devastation around Tambora was total: the area was wiped by the explosions, ash fall, whirlwinds (probably pyroclastics), a tsunami, and afterwards starvation. Estimates range between 60,000 and 120,000 casualties. The nearest known survivor was 20 km from the summit, and it didn’t include Mr. Israel. His demise was part of the largest natural disaster ever to hit the British Empire.

Tambora’s demise was the biggest explosion on Earth since 1453, or perhaps since 1257. An interesting aside is that the 1815 and 1257 explosions happened within sight of each other: from the remnant of Tambora, the peak of Rinjani at 160 km distance is visible on the horizon.

The eruption had an enormous effect on Indonesia. But the rest of the world would not escape. It just took time.

World without summer

Boston, June 1816

The weather was atrocious. It had been a fairly mild winter with less snow than usual, whilst spring had been colder than usual. March and April were cold and dry, and the grass would not grow. Cold fronts regularly penetrated far south and there was frost in May where normally the last frost would have been in April. Merchantmen had reported fields of ice floating in the Atlantic, east of the St. Lawrence. But June started out warm – it looked like summer had finally begun. Crops began to grow. That was much needed as by now the winter hay had run out. June 5 was the warmest day of the year. But on June 6 a strong northwesterly wind set in, and it brought dramatically cold weather. Temperatures plummeted and snow flurries began to fall.

In Boston’s history, snow so late in the season remains unique. Northern New York State and parts of New England had a full-blown snowstorm, dumping 6 inches in places. Frost badly damaged the still tender crops; households had to restart the winter fires to stay warm. Comments in various diaries include “the most gloomy and extraordinary weather ever seen” and “this is beyond anything of the kind I have ever known”. The cold and frost lasted for five days. Birds, lambs and corn died.

The Reporter (a Vermont newspaper) gave an account of the strange weather:
The Season — It is believed that the memory of no man living can furnish a parallel to this present season. From every part of the United States, north of the Potomac, as well as from Canada, we have accounts of the remarkable coldness of the weather, and of vegetation retarded or destroyed by untimely frosts. In Montreal, on the 6th, 8th, and 9th of June were falls of snow, and from the 6th to the 10th, it froze every night. Birds, which were never before found except in remote forests, were then to be met with in every part of the city, and among the [flocks], and many of them benumbed with cold, dropped dead in the streets. From the northern and western parts of New York, and from Maine, we have received accounts of summer snows, and winter lingering in the lap of June; and the most gloomy apprehensions of distressing scarcity are entertained by those who witnessed the phenomena.
(The Sun would have used simpler and more colourful language. And blamed Europe.)

The strange weather continued throughout the summer. The remainder of June was warm but there were more cold snaps in July and August, and frost was recorded every month. Some summer days had temperatures below 5 C (40 F) as far south as Connecticut. The summer of 1816 was 2 C colder than average, the coldest on record. And it wasn’t just cold. Extraordinary drought did as much damage as the frost. Hay, fruits, and vegetables became scarce. Corn seemed to recover in a gloomy August but two further frosts killed the crops. The corn harvest was as low as 10% of normal in some areas. The drought finally broke in September but this was too late. One of the many victims was Thomas Jefferson: he had just left the presidency and returned to farming, but his crops too failed and he was left in debt. It became known as the years when farmers both froze and starved.

There was much discussion on the cause of the terrible weather. Some blamed the sun spots which were visible, whilst others blamed a total solar eclipse. Some just quoted Job, ‘By the breath of God frost is given‘. None connected the weather to a volcano which they had never heard of. Only in 1920, more than a century later, was this connection finally made.


The climate downturn also affected China, but here it started earlier. There was frost in Hebei in September 1815, followed by freezing weather in Yunnan where famine conditions would occur in the following year. Yunnan (next to Burma) is a rice-growing area, and frosts wiped out the rice. Taiwan had snow and frost in December, something that is very rare. The monsoon rains were less than usual for the following three years.


Europe, too, was badly affected in the summer of 1816. It shared with New England the cold weather but missed out on the drought. The diary of pastor Arnold Borret from the Netherlands provides some details. It reports snow on May 13 and later says that the weather was very wet. The winter fires were kept burning until July. The weather improved in August, but the first half of September was again very wet, with extensive flooding. A mosquito plague brought thick layers of dead flies on the canals. It was difficult to store the hay. Later in September the rain came again, and the second hay harvest was completely lost. Food prices rose, and much of the cattle had drowned. The alternation between drought and excessive rain continued until March 1817. From February 1816 until March 1817, sunny weather never lasted more than two consecutive days. On 10 March 1817 the sun returned and the weather finally improved. It is notable how much the weather is mentioned in his diary!

It can be difficult for us to envisage what a mosquito plague was like. I have seen clouds of them thick enough to black out lamp posts. But that was 40 years ago and now you only see a few at a time. The plague in the Netherlands is in contrast to New England which had a mosquito-free year thanks to the drought.

We know from other records that frost occurred in Europe in June and in August. London had snow on 30 August. Central Europe had snow in June 1816, reportedly coloured red and brown in Hungary; this may have been from Saharan dust which can reach these regions fairly frequently. The coldest weather was reported from France and Switzerland. Rain and storms are mentioned, for instance Merionethshire (Wales) had only 3 or 4 days without rain between May and October 1816. Geneva too reports an almost perpetual rain in June 1816.

It hadn’t been this bad everywhere. Russia and the Ukraine had slightly warmer weather than normal, and north Scandinavia had normal temperatures.

Facts, numbers, and units

Weather descriptions from diaries can be telling, but they often lack hard numbers. A description of ‘snow’ gives a good indication that temperatures were near or below freezing, but ‘cold and wet’ is open to interpretation. To know what really went on, numbers are needed. By 1815, actual weather measurements were taken at many places, and so such data is available, at least for the western world. Both atmospheric pressure and local temperature were measured.

But using these historical data can be complicated. For instance, the measured pressure is affected by the local temperature: a correction needs to be made if the temperature changes. These temperatures were listed at ‘professional’ locations (often observatories) but are rarely available for the many ‘amateur’ locations. Science, in these days, often was done as a hobby rather than by professionals (and isn’t that what VC is about as well?).

Another problem is that the metric system had not yet been universally adopted. Each country still had its own measurement system, and the listed numbers cannot be interpreted unless the units are known. Pressure was measured in inches – but not all inches were the same. The UK and America used the English inch (25.40 mm). Some countries used the Paris inch (27.07 mm). But other countries used neither. Sweden used the Swedish inch (29.69 mm), Austria the Vienna inch (26.34 mm), the Netherlands had an inch of 26.15 mm, and Spain used one of 23.22 mm.

The barometric measurements are listed in long tables. These normally give the number of inches, followed by a subdivision (the remainder). The scales used either 4, 12 or 16 subdivisions, depending on country, apart from Sweden and the UK where decimal subunits were used.

Reamur/Celsius thermometer

Temperatures were normally given in Fahrenheit or on the Réaumur scale. The latter was a French system where the freezing point of water was set to zero and the boiling point to 80 degrees; it is still sometimes used in food production. Fahrenheit originally defined his scale using zero degrees as the melting point of an equal mixture of water and salt, 32 degrees for the freezing point of water, and 96 degrees as body temperature. The latter was measured from alcohol kept in the mouth of a healthy (not feverish) person (for which he used his wife). He used the number 96 for this because it is divisible by 16, the number of subdivisions he used. This is also the reason why the freezing point of water corresponds to 32 F. There is some dispute whether he actually used the water/salt mix. The Fahrenheit scale has since been redefined and the new Fahrenheit scale differs by a few degrees at the highest and lowest temperatures from the old one. By 1814, the new Celsius scale was just beginning to become established; it had been adopted in France and in Sweden.

Calendar dates had been unified in most places (but not Russia). Time was normal given as local solar time – there was no single time system even within a single country.

Distances were also far from unified. For example, for measurements made from a ship in 1816, the location was often given in ‘seemeile’: this could be an English nautical mile, but the same word was also used for a ‘league’, which is three nautical miles. You can imagine the confusion.

Correcting for all these complications, it has been possible to numbers on the post-Tambora weather, and to interpret its patterns. The first winter, 1815/1816 was a bit colder than usual in Europe, but not extreme. Initially it had been fairly mild, but the cold weather hit in late January and early February 1815. The barometric measurements indicate a typical blocking high pressure system over Scandinavia, and low pressure systems in the Mediterranean, giving rise to easterly winds from Siberia. On Feb 10, the temperature in London dropped to -19 C (measured at 2 meters height, not at the ground). This was the lowest measured temperature there since 1797. Scandinavia was a tad colder, with Härnösand (central Sweden) reporting -37 C and Ylitornio, on the northern Swedish-Finnish border, -40 C. This also was colder than average but not extreme. January 1814 and December 1817 (before and well after Tambora) were colder.

Now the weather deteriorated: the spring brought little warmth and the summer never came. In early July, central Europe reported temperatures a staggering 7 C below average.

Here is a plot of average temperatures over these years. The winters were not extreme, but the summers were cold. In hindsight, the cold summer weather first appeared in July 1815.

Temperature anomalies in Central Europe with respect to the average for the period 1801-1830. The horizontal bars are the anomalies with respect to the average for 1961-1990. Source: Brugnara et al. 2015 https://www.clim-past.net/11/1027/2015/cp-11-1027-2015.pdf

Weather patterns

The weather in 1816 was unique. But why the delay of one year? And what was the weather pattern?

Tambora erupted in April, at the start of the southern winter. The surface wind was from the southeast, and most of the ash went into the sea. But at higher altitudes the airflow was different. The tropical jet which distributed Krakatau’s (and Toba’s) ashes around the world does not blow in April. Instead, the normal circulation of the higher atmosphere is such that most of the sulphate may have gone south. Indeed, some studies (but not all) show that more sulphate from Tambora was deposited in Antarctica than in Greenland.

In that case, why was the weather impact so significant? This may be because Tambora did not stand alone. A major (but unidentified) eruption in 1808/9 had already pre-cooled the climate. Tambora amplified an already existing situation. (The Mayon eruption in 1814 may have had a small effect as well.) This is very similar to the eruption pair in 536/540. However, it should also be noted that the single Rinjani eruption from 1257 had an even worse impact on weather. VEI 7’s do carry a lot of power.

Pressure measurements indicate that the summer of 1816 had a weak Azores high and a strong Icelandic low in the North Atlantic. The resulting airflow was sending frequent low‐pressure systems on a generally westerly and northwesterly route towards Europe. Hence the cold weather and the incessant rain. The back flow brought warmer weather than usual to the Ukraine. North Scandinavia escaped the weather systems and had average to above average temperatures. Climate models support this pattern after a tropical eruption: it corresponds to a positive North Atlantic Anomaly. Immediately after a major volcanic eruption, Western Europe tends to have a mild and wet winter, while Spain has a dry one.

The North Atlantic was cold with more reports of sea ice than normal, but there was an exception around Greenland where there was less sea ice than normal. East America was very cold, but the west of the continent appeared to have had warmer weather than normal as indicated by tree rings. Thus, it was not uniformly cold across the northern hemisphere: a significant part of the weather came from the changing circulation. The average temperature was still among the lowest recorded, but it was down by much less than the weather in Boston and Europe would have suggested.

Solar insolation

The climate models confirm that the coldest phase occurs a year after an eruption. They also show that the southern hemisphere is much less affected, because it is mostly ocean and this has a more stable temperature (ocean has a much higher heat capacity than continents). The heating of the stratosphere (where the sulphate absorbs sunlight) makes the polar vortex stronger. As the sulphates slowly descend, the warm layer in the atmosphere descends with them.

The models also show that the Asian monsoon weakens, bringing drought to southeast Asia and India. This may be related to the Yunnan famine. Drought is also predicted in the tropics, two years after the eruption. This may indeed have happened in Indonesia, suggested by tree rings.

Dry fog

The effect on temperatures shows that there must have been a significant sulphate haze in the stratosphere. But there is remarkably little mention of this in documents of the time. Starting from 15 May 1815 until the end of the year, London reported lurid sunsets, with red and orange colours streaked with dark bands. In May 1816 Washington D.C. was worse affected: “the whole atmosphere is filled with a thick haze, the inconvenience of which is not diminished by the clouds of impalpable dust which floats in the air“. At the same time in Virginia it was reported that “the atmosphere is continually impregnated with a fine dust, very injurious to respiration“. But this dust cannot have come from Tambora and more likely was associated with forest fires, caused by the drought. More relevant is perhaps a report from Boston in July 1816: “The Sun’s rays, it has been frequently remarked, have not their usual power.”

There was also no report of blue and green suns, as was seen after Krakatau. Part of the reason for this could be that much of the ash and sulphate initially was blown to the south. The coloured suns of Krakatau were mainly seen in the first month after the eruption: after that the particles of the particular size (1 micron) to discolour the sun had dropped out of the atmosphere. The sulphate layer may only have reached the North Atlantic region midway through the summer, by which time the lack of warmth of the sun could have felt like normal progressions of the seasons. A weakened sun may even have been quite nice in the harvest season.

Source: Oppenheimer, Progress in Physical Geography 27 (2003) pp. 230–259

Still, modelling of the sulphate deposits, plus reports of sunspots visible in the daytime (which requires considerable dimming) suggests that the sum must have been dimmed considerably. The models suggest this peaked in September 1815 but the dimming may have been significant even three years later.

In Europe, few seem to have noticed a lack of power in the sun. The people may have been accustomed to haze by the sheer number of eruptions around this time. The lurid sunset in London in 1815 have already been mentioned. But similar sunsets had also been seen in 1814, caused by a major eruption from Mayon in February 1814. In Italy, Vesuvius was in a long-lasting eruption which caused frequent ash clouds across the country. And of course, people still remembered the disaster fogs from 1783 which covered much of the continent – all new fogs paled in comparison to the memory of that. A weak sun and a dry reddish fog was noted in 1814 in Italy (presumably from Mayon), but there are no similar reports from 1815 and only one fog report from 1816 (9 and 10 July 1816). In January 1817, a fog was reported stretching from Sicily to England, but it is not noted whether this was dry fog or a normal winter fog. Perhaps the exceedingly poor weather was hiding the sun so much that the high level haze was missed.

Turner, Chichester Canal. The colours may reflect Tambora’s sunsets.


Hunger and disease

The weather of 1816 led to the last major subsistence crisis of the western world. Food prices rocketed throughout 1816 and 1817. The US was hit. It had sufficient resources nation-wide and overall there was enough food to last until the good harvest of 1817. But individuals had a hard time: people went bankrupt, and suffered hunger and starvation. The UK was hit but managed thanks to massive food imports in 1817, mainly through the port of Liverpool. However, the hardship was still evident from the increased migration to America. The cold and damp of 1816 also claimed victims, including the author Jane Austen. Ireland was hit worse, and 44,000 died of typhus: the epidemic was linked to the malnutrition after the poor harvest.

Central Europe was worst affected. The continent had been devastated by years of war (the battle of Waterloo was only two months after Tambora). It shared in the poor harvest across Europe: wheat production was down by 75% across France, England and Ireland, but Central Europe had the added problem that food transport within the continent was slow – this was before the railways, still the age of the horse. And people were generally poor. After the wars, many ex-soldiers were looking for work, but there was none. This was the year of potato riots. Perhaps 200,000 people died of famine. Different countries dealt with the issue differently. Some imported as much wheat as they could (the Netherlands, France, England). Others used an export ban on wheat (Southern Germany, Canada). But the export bans didn’t work as well as the food was still priced out of reach of the needy. And it led to mis-distribution of food. There was mass starvation in Appenzell, while nearby Basel had plenty of bread but was not allowed to export it to another Swiss canton. Sometimes good intentions had unintended consequences. The crowded conditions around the soup kitchens which had sprung up led to the spread of typhoid.

Cholera followed. It started in India and rapidly spread worldwide, reaching London in 1818. The link between the cholera epidemics and Tambora is not proven, but the timing agrees with the impacts of Tambora. The explosive spread of the disease is perhaps related to the failed Asian monsoon.


The cultural impacts of the missing summer were different for each country. In Indonesia, where the local area was devastated, the local culture and language was effectively wiped out. Elsewhere, the impact was less drastic but not unimportant.

In America, the area west of the Appalachians had been opening up, and the starving farmers saw an opportunity. They began to migrate. Reports from North Carolina and Ohio talk about ‘roads covered with wagons’, with numbers of migrating farmers ‘exceeding belief’. The nation was changed forever by this westward migration. This was the time when the bible-belt from Ohio to the Great Lakes and the burned-over region in western New York state became important. The people moving there brought with them a strong religious identity, but also an individualistic mindset. This mindset was strongly set against slavery. The abolition movement which would eventually lead to war was led from this area. Here also was the first college to accept black students. Joseph Smith was part of a family which moved here in 1817 from Vermont: he went on to found the Mormon church. In a way, the Mormons too can trace their roots to Tambora.

Europe responded differently. The best-known cultural memory of the non-summer of 1816 remains the novel “Frankenstein” by Mary Shelley (at that time still called Mary Godwin). This novel was written while they (young Mary Shelley, her future husband Percy Shelly, Lord Byron and his personal physician) were staying in Geneva. They had been planning to spend the time sailing on Lake Geneva, but the appalling weather prevented this. Once their conversation ran out, they challenged each other to write ghost stories. This was the start of the Romantic movement, a culture which to us now seems both impressive and depressive. It was deeply susceptible to the gloom of a summer that never came. Frankenstein came out of this.

A shift was also seen in science. Until the 18th century, western thinking could rely on the promise that the Earth was designed for humanity. This view is found even in the ‘Theory of the Earth’, the master piece of the Scottish geologist James Hutton. But cracks had been appearing. George Cuvier, from his study of fossils, has concluded that there had been various catastrophes and upheavals. Comte de Buffon, in ‘Les époques de la nature’ (1778) claimed that the Earth had undergone a process of gradual cooling since its creation and proposed that it would eventually become too cold to be inhabitable. The three opposing views constituted a vigorous argument. The current climate is in some ways a rerun of these arguments, since it too involves people who believe that it will all work out, people who predict catastrophe, and people who believe that any action is futile. This was the world into which Tambora exploded and brought its year-long winter, seemingly siding with Comte de Buffon. Percy Shelley wrote about the glaciers of Mont Blanc, and envisaged how they would expand until they overran the entire valleys. He quoted de Buffon ‘I will not pursue Buffon’s sublime but gloomy theory — that this globe which we inhabit will at some future period be changed into a mass of frost by the encroachments of the polar ice, and of that produced on the most elevated points of the earth.

Romanticism developed while this discussion was on-going, and it tried to deal with the sense of a world in which humanity was marginalised. Frankenstein lives in this conflict. The novel is about a search for a place of safety which the Creature never finds. In the end, the Creature prefers the ice and cold: ‘These bleak skies I hail, for they are kinder to me than your fellow beings’. The Creature is better suited to the new world than his creator who abandoned him. If this was the world of Comte de Buffon, the future was for him, not for us. In the lost summer, other people suffered hunger. The Romantics suffered despair.

Romanticism was a response to the loss of the certainty of a caring world, a phase any teenager has to get through. Tambora did not cause Romanticism. But Tambora did give it its lasting power.

And there was one further, long-lasting impact. The widespread hunger led to questions whether governments should step in to help. The philosophy up to this point had been that it shouldn’t. Governments were for governing states, not to help individuals. Malthus had argued that relief of the poor “relieves them for a short time, but leaves them afterwards in a condition worse than before”. Others claimed that funds raised for employing destitute people were wasted. The most inhumane was perhaps the otherwise ‘enlightened’ Jean-Jacques Rousseau who argued that “it is quite a good thing that a certain number of people should get killed now and then” in the interest of population control. The famine of 1816 and 1817 began to change opinions, and governments started to accept that it should protect all citizens, not just favoured groups, even if this required direct public intervention. Change was slow. The process would come to a head three decades later during the Irish famines, made so much worse by the failure of the government to act. (In fact this future disaster was already foreshadowed in 1816/17: the English government took care of its own people, but completely ignored the plight of the Irish.) This change of thinking was as significant to Europe as abolition of slavery was to America.

Tambora did not change the world on its own. Just as it amplified the effects of another eruption which had happened seven years earlier, so it accelerated social and cultural changes that were already in progress. It exploded into a volatile and unstable world.

Horse power: the end

But one development brought about by Tambora changed our world more than any other. And it began in a badly hit part of the world: southern Germany.

Karl Friedrich Christian Ludwig Freiherr Drais von Sauerbronn (1785-1851) lived in Karlsruhe, and as the long name implies, came from an important family even though he was a bit of a student radical. He is also known as Baron Karl Drais (a ‘Freiherr’ was a baron), Karl von Drais, or just Karl Drais (after he foolishly surrendered his title late in life). He studied physics in Heidelberg, and afterwards, with plenty of spare time (being wealthy but not needed), became an inventor.

His time came in 1816. At this time, horses were still the only means for fast transport. However, they had drawbacks. A horse and carriage takes up a lot of space, which limited the number of people on the road. They were not really suited for mass transport. (In fact, traffic jams began to develop at this time.) In cities, horses were far from ideal because of their biological exhaust system. And when famine hit, horses were not spared. They were eaten, or starved. (If you don’t fuel a car, it will still be there a year later. If you don’t fuel a horse, it isn’t.) A transport crisis was looming.

In response, Karl Draise came up with a two-wheel, feet-powered conception. He brilliancy was in realizing that two wheels can be stable, something that is not obvious from looking at it. In this he perhaps was helped by his physics education. The contraption was first demonstrated in June 1817: he managed to cover 14 km in one hour. It was three times faster than walking, without any horse being involved.

His two-wheeled ‘velocipede’ became known as the Draisine. It was nick-named the hobby-horse. The driver sat between the wooden wheels, and used his feet on the ground (a bit like a modern Flintstone ) to propel the Draisine forward. Once some speed has been reached, feet can be lifted, at least for a short while. The hobby horse needed no feeding, no servants, produced no exhaust, and was several times faster than walking. It was a winner.

Or at least it should have been. It turned out that the deeply rutted roads of the time were not well suitable to it – and do realize how heavy this wooden machine was. The Draisine took of as wildfire, but people used it to ride not on the rutted roads but on the city pavements where their speed caused mayhem and accidents. City after city banned it. Eventually the bicycle was developed from it, but only when the roads had been improved to suit this new, environmentally friendly, non-biological transport.

Karl Drais had an eventful life, punctuating new inventions with some poor personal choices. But he is remembered for this hobby horse. It paved the way for our modern society, shaped by fast, cheap transport. When he died in 1851, just down the road from him lived a young Carl Benz. The rest, as they say, is history.

When Tambora blew it, the weather affected Europe and America many months before news of the eruption reached. The people living through it never made the connection: the volcano acted from the shadows. It happened at a time when the world was ready for change. It pushed us toward a change in thinking, a change in caring, and a change in moving. The French revolution had been a failure, as human revolutions normally are. Tambora’s explosion caused a revolution that lasted; it reshaped our world. The climate soon returned to the situation before Tambora. The world never did. Nothing has altered, but everything’s changed. George Cuvier would have approved. Volcanoes are the movers and shakers of our world. Our lives are their legacy.

Albert, September 2019

Deus chevaux. A transport revolution

139 thoughts on “Tambora, the lost summer and the hobby horse

  1. Albert, awesome writing as usual. I hope you are planning to compile your writings and publish them.

    • Thank you! I have my favourites on VC. The one about Silent Spring, the one on the Stones of Calanais and the one on the Drakensberg are ones I enjoyed writing because these topics are close to my heart. This one was fun too but harder to get together, in part because the story dates didn’t fully fit until I remembered about the Mayon eruption. Whether I would publish them – perhaps if the occasion arose. But you are welcome to read them here for free.

  2. You write so well i had to turn up the heater. 🙂 Your comments about horses brought to mind a story i heard from a 90 year old lady in 1970 so i’m guessing she would have been about 19 to 20 in 1900. She described seeing her future husband (when i knew him he was still a handsome elderly Basque) for the first time…. She was standing on the porch and he rode up on a golden palomino horse… “How romantic!” i gushed, and she said…”Nonsense! Everyone rode a horse then.” i still smile about it… she was a no-nonsense kind of lady. but back to volcanoes….. looking at the past makes one understand how important it is to keep an eye out for the next big eruption. Thanks, Albert and to the warmer climes: The rains have finally started and the remanents of the last Japanese Typhoon is rounding the pacific and filtering into my yard. It’s 50 degrees F this morning and the house needed a little heat. Best!motsfo

    • I love these recollections because they illustrate so well how much things have changed. Now the question was who owned that horse…

  3. Great article. I happen to had the entire London Times cover to cover for the years 1815-1818, and came across a curious theory of the reason for the disastrous harvest of 1816 in a speech by Lord Castlereagh – responsible for much British government policy in the years in question – to the electors of Downshire in the summer of 1818. He considered it a visitation of providence to prevent the victors of Waterloo from developing excess hubris.

  4. The biggest problem about transport, though, was cost. A horse was very expensive. One draft horse could be as much as the annual income of an average farmer.

    Has that really changed, though? Where I am, a worker earning minimum wage but given full-time hours would get a bit under $30,000 in annual income … fairly close to the typical price tag on a new car of a basic, non-fancy sort. The big change seems to be the accessibility of loan financing for such big-ticket items to the everyperson.

    Rain and storms are mentioned, for instance Merionethshire (Wales) had only 3 or 4 days without rain between May and October 1816.

    So, a typical UK summer then. 🙂

  5. The Turner pic isn’t the Fighting Temeraire, but Chichester Canal. But it’s not the famous painting of Chi Canal, it’s some kind of study. Where did you find the image?

  6. Wonderful article, thank you!
    It sort of reminds me of my wife’s grandfather, Edward, who was born around 1888 and lived to the ripe old age of 98. His father (of whom he spoke frequently) was a London Hansom Cab driver (horse-drawn) who was put out of business by new-fangled horseless carriages. He went on to be a teacher, a profession his son followed.
    At the time Edward spoke of him, it was as if he had lived just a few years ago. Strange how sometimes family experience can reach far back!

  7. a brilliant post, thanks Albert. Who would be the next contender, or is it already on the way and we don’t know ? the more things change, the more they are the same

  8. England and America were poised on the brink of dramatic changes in 1815. It’s early in the Industrial Revolution, and the introduction of trains and steamships made a huge change in both the speed and frequency of personal mobility – and also communication. My grandfather (born 1880) could get around nearly as conveniently and rapidly on trains and streetcars in the New York area as I or my daughter can in a personal automobile – the only big difference has been long distance travel in passenger aircraft. Communication is another matter. Now i can communicate instantly, at very low cost, with people all over the world. In 1960 it took a week to get letter from my home in Oregon to London – the cost of postage was relatively low but telephone calls were too costly for anything but emergencies or the wealthy. In 1880 the time was more like two weeks, but again, affordable. By the time you go back to 1815, the time, affordability, and reliability of long-distance communication are vastly different.

  9. Which volcano erupted in 1493? Google reveals nothing.

    • GVP shows this;

      “During the early stages of an eruption, the GVP acts as a clearing house of reports, data, and imagery which are accumulated from a global network of contributors. The early flow of information is managed such that the right people are contacted as well as helping to sort out vague and contradictory aspects that typically arise during the early days of an eruption.”

      GL Edit: Note, the first GVP links goes to GVP itself, the 2nd GVP link goes to the Wikipedia Article about them.

      • Etna only erupted in 1493?
        That would be a surprise on almost the same scale as if Stromboli would do only one eruption in a decade. 🙂

        • The list is filters for start dates beginning with “149,” so it covers a decade of eruptions.

          Side note for all, it’s via the extracted spreadsheet for all GVP listed eruptions. This method of selection may not be available in the GVP site itself.

    • Typo: this should have been 1453. It is believed to be Kuwae.

  10. Great article!
    Tambora didn’t even produce the third most intense volcanic winter, but hearing about the climate effects are still amazing

  11. Tambora was an impressive eruption indeed!
    150 times larger than St helens plinian phase… quite stunning
    Its much much larger than any other eruption thats been photographed so far.

    • Yes, there has been no similar eruption since. The chance of one is between 0.1% and 0.3% per year.

      • Unlike southern iceland rifting and cascadia fault, that will reach their failure point in the not distant enough future.

        • Cascadia probably has similar odds. Iceland has far more frequent eruptions, but Laki-sized fires are again of the order of 0.1-0.2% per year. The question is, what odds are large enough to take pre-emptive action? The Dutch build their sea dikes for 0.01-0.1% floods (chance per year). The UK isn’t interested in odds of less than 1%. Different approaches. Of course, the flood odds are based on past events. In the future they will be more frequent. Forward modeling is essential for flood risks. For volcanoes, that only plays if there are signs of an impending eruption.

  12. This sent me on a journey down memory lane. Being inside the caldera was highly interesting, for being a caldera that was so violently ripped apart it is quite active and we found several lava flows from post-caldera eruptions. More than are listed in the GVP.

  13. Exciting and entertaining as allways! When will a similar sequence of events hit our modern world and what wil come out of it??

  14. The really scary thing is that I’m not sure our society could survive another similar harvest. There are not capacious colonies where food could easily be drawn from as these are now all net importers. Maybe the USA could help us out but they would be short too.

    Bear in mind that typically farmland then (until 1940) would constitute a lot of grassland and very little in the way of arable crops. Heavy land could not be ploughed for example. So perhaps more than half would be grassland, and the animals who lived on it. With May frosts (definitely june) cereals produce ears with no grains and no yield so these would be fed (green) to livestock and really we would move to a meat and veg diet with very limited grains and vastly lower net farm output.

    We could not do that today. No grass, no livestock.

    • That is interesting. Do note that Tambora affected some areas worse than others. The eastern US and western Europe were hit, but the Ukraine was not and that country could probably feed much of Europe if it wanted. Transport is essential

      • Ukraine grain production 70MT.
        EU grain consumption 300MY.
        EU production 310MT
        UK grain production 30MT (bet that surprised you).

        Bit of a gap there.

        • I think Alberts general idea was that the Ukraine could fill in a deficit, and not to replace the entire harvest.
          I am not at all surprised that the UK is almost self sufficient on grains. Most countries try to be, or are self sufficient.
          The reason for this is that the price vs transport prices do not pan out well for something cheap like grain. Even if the production cost is comparatively high, as soon as you put in transport cost it tends to make it profitable to produce it locally.
          Also, many countries still try to be self sufficient on it for very obvious reasons.

          General rule is that if the market price is below 1€/kg it will never be profitable to import it, with the obvious caveats of things that are not possible to grow like rice. Rice typically FOBs at 0.9€, but will be above 2€ in the stores, kind of proving my point.

        • Very interesting numbers. The Ukraine could, in my opinion, produce much more than it does, whic is already a quarter of the entire EU consumption (knowing that is not where it goes to). It is perfect farming country. As Carl says, long distance transport of wheat may not be economic. But if food production declines and prices rise, that changes.

    • I actually believe we would fare way better than the XIX century society,  because we have several advantages. First, we start from a warmer climate, that make us less vulnerable to a sudden cooling.
      Second,  we would know in advance that a volcanic winter is coming and we could plan for it in many ways, stocking up food, changing crops or timing in places at risk of late frosts, diverting land from non food crops (starting from biofuels) to food crops and any other emergency measure to increase production and decrease consumption.
      Third, we are an affluent society where very few people live with a barely sufficient food intake and a lot of food is wasted, we could survive with less food without starving.
      Fourth, in a globalised economy where transport is very easy to compensate failed harvests in a region with imports.

      A Tambora sized eruption would be challenging but manageable, if we can maintain international cooperation.

      Something bigger could be more difficult to deal with, especially if it directly affected a large production region through ashfall during the growing season, such as an eruption that hits the great plains in the US during spring.
      With a large direct effect on first year harvest and a subsequent volcanic winter things could easily get dangerous.

      • I think you should read the article we just posted about exactly this.
        Basically all of your assumptions are wrong.
        (And yes, my actual daytime job is producing and moving food across the planet)

        • Carl is referring to his recent post. A Tambora-like event would cause problems but if we manage things well, we should get through. As you say, a larger event would be worse. But we are not managing things well. In the affluent world, no problem. But if it hits Africa, who will help? The US seems hardly able to even help out Puerto Rico and that is its own territory. Willingness to help will be essential. Crop changes are not trivial and probably couldn’t be done to significant degree in a few months. Other people will know more about this than I do.

          Carl has pointed out that we are also running into other problems, with global warming running ahead of schedule. It seems a common pattern that the most significant volcanic winters happened at a time there were already other problems, and it amplified these. Tambora came immediately after the French wars and Europe was hit so hard because the economy had pressure (very high unemployment) and no resilience. The US had weather just as bad but managed much better, as it was in a decent position to begin with. A Tambora in 2020 may be fine (well, that is hardly the right word). The same event in 2040 could hit much harder.

          • I agree completely with you Albert, I hadn’t seen your reply before sending mine.

        • I’ve read your article last month and I found it extremely interesting,  but I don’t think it contradicts my argument. Current temperatures are over 1°C warmer than two centuries ago, that would make a difference in case of a volcanic eruption where cold weather is the largest source of disruption. Weather patterns following large volcanic eruptions are quite predictable, so we could prepare unlike XIX century farmers that were oblivious of what was going to happen.
          Right now food resources are still plentiful, even if future perspectives are not as rosy  (and that could pose serious problems in a few years or decades). But right now governments are not taking serious steps to address the problems, while a catastrophic event would force them to mobilize all available resources and give some serious thought to food safety. We would have several months to plan, as the worst impacts on agriculture would not be felt in the first harvest after the eruption.

          • Okay, I will bite.

            Temperature is one thing, and you are correct that we are almost 1.5 degrees warmer now. But temperature is only one part of the equation, another part is the amount of solar energy giving energy to the photosynthesis. After a large eruption this would be lower and adversely affect food production.

            Yes, we can predict weather patterns. Sadly this will be to late since we would need to predict the eruption more than a year prior to that to try to increase somehow food production. And even if we used weather predictions to try to limit the impacts, it would still be a limitation and not holding the same level of production.

            I am sure that the politicians would react after the fact, not much they can do during the event and in the year/years after. Only thing they could do would be to reinstate free trade again. I do seriously doubt they will do that, instead they are far more likely to go down the death trap of protectionism.

            Next harvest? That depends on when it happens. And to keep it real, even the best mitigation at this point would just limit the loss, not reinstate normalcy.

            And surplus? Well there is not much to have. 2019 did not give better yields than 2018, and in 2019 the free trade network is almost gone. And that forced China to buy from new sources emptying out entire countries (like Chile).

            Obviously the greatest death toll will not be in the rich parts of the world. We will just gripe about prices, the deaths will be in the poorer parts. If we now vector in that there are almost 7 billion more of us, well Tambora would probably push it into the millions of dead, whilst something like Laki would push it into tens of millions.

            Now Ukraine. It is a fantastic spot for farming. With two glaring faults. It is already feeding Europe and Russia. Second problem? It will be the hardest hit region, during almost every large eruption there has been no harvest in Ukraine.

            And Boris Jonsson will blame the EU for the eruption.

      • This may be the right time to remind all that political cynicism will have a very significant role to play in the survivability of communities in such a context.
        I can’t find a reference at the moment, but I believe that it was in the early 1980s that Caspar Weinberger stated that in decades to come, food might be one of America’s most potent weapons.
        Now I’m not pointing a finger specifically at America, because I believe that there are many who might use access to food as leverage to further their own agendas.
        Doing so would not only exacerbate an already dangerous situation, but would also destabilise whole regions of the World.

  15. A little bit off topic, but an awesome paper was published on the Chicxulub impact titled “The first day of the Cenozoic”.

    Geologists drilled into the impact peak ring and from the samples were able to reconstruct what must have happened in the aftermath of the impact (hours / days). Even a volcano like Tambora would be hard pressed to match the devastation caused by the impact, tsunamis, and conflagrations that came afterwards.


    The paper is open access and everyone can read it for free.

    Earlier this year another paper described the consequences of the impact on a fresh water lake in what is now North Dakota.


    Unfortunately, this paper is behind a paywall….

    • Tambora is a tiny little fart compared to Chicxulub.
      Chicxulub generated impact temperatures of 20 000 C
      And many tens of thousands of km3 of superhot vaporized rock materials sent into the atmosphere.
      This fanned out over North America
      Setting fire to the whole North american continent in minutes.

      • There was some sort of study on the news this week, I think, that reported that after the impact, the crust rebounded upwards some 10km within seconds, creating an instantaneous Everest-like mountain, which then went down again. Can you imagine that?

        That’s nothing compared to even a Toba-event…

        Surely magma must have been released!
        Possibly also at the antipodes (but that’s a controversial topic)

      • Chicxulub must have been a heck of an impressive sight

        The fireball after the impact is at start a 200 km wide ball thats 20 000 C or more.
        Then it expands to a huge white hot bright plume . Full of vaporized rock.
        Very bright and hot.

        The ejecta curtains formed a “rooster tail,” a gigantic jet of boiling material, which exited the atmosphere rising into space, spreading out over North America. That ejecta material is 5 times hotter than the surface of the sun, and it set fire to everything on the ground.
        Under the glowing skies in america, the large dinosaurs coud not hide from it
        they became roasted. Huge forest fires engulf North America.
        Even worse it is when all this materials starts to re – enter the atmosphere.
        The debate rages on how bad the Chicxulub ejecta firestorm was.

        The event goes very quickly instantly of course geologicaly.
        Weeks after the impact earth is plunged into an asteorid winter.
        There is alot of debate just how severe the Chicxulub winter really was.
        Alot of things where destroyed, but alot of things surivived the event.

        The comming passage of 0,6 solar mass Gliese 710 C s in the innermost ort comet cloud may throw these events again towards our planet…Major comet shower? when Gliese 710 C pass by in 1 million years.
        And 30 km wide asteorid Eros will likley evolve into an Earth crosser in around 1 million years too. I hopes our descendands haves to tools to defend themselves.
        Large impact events ( as large as Chicxulub and larger ) are proably the only thing that really can make us humans go exctinct

        • Adim! edit to 5 times hotter than suns surface for Chicxulub ejecta
          It was about 20 000 c

          Not 75 000 C¨
          I wrote wrong

          Edit: Wrong written rewrote as requested.

        • {snicker} At first I read; “Under the glowing skies in America, the large dinosaur cloud{The sort of thing that makes you go “Eh?” and go back and read it again.}

          Which is probably what they were in this hemisphere after the initial impact. Radiant flux was likely 118 greater than the sun for about 20 minutes 500 km from the site.

          – – – – > Poofasaurus

          Similar to the nightmare daydream sequence of Sarah Conner in Terminator 2.

    • The new research is well worth reading. The North Dakota paper should be viewed with more suspicion. It is a layer that is well below the KT boundary and the evidence that it is KT-impact related seems too slim, to me.

    • Sorry about that, I should have double checked. I downloaded it at work, which gives me free access automatically.

      It will be open access in ~6 months…

  16. What an enjoyable good (in dutch: geniale) post this is! Got me thinking: wouldn’t the impact of 9/11 be very similar. A world in the progress of changing, getting a kick in the but?

    • AHAhahahah!

      I know which money is the cleanest of the world!
      Croatian Luna

      And the dirtiest?
      The Romanian Leu

      This is priceless unimportant research!

      I love these guys!

      • Well we now have washable plastic notes in the UK. Inconvenient to use -they’re slippery- but I suppose ideal for money laundering 🙂

    • i suppose the currency most dangerous to health is the one spent on tobacco.

    • To be honest its ig to a tee. Makes you laugh then makes you think. Certainly transmission of dangerous strains on currency could be a significant source of infection and a perfect way to propagate a bio-weapon. Perhaps self-disinfecting notes might be worth a consideration.

      • Copper microfiber would be a good idea.

        Copper/Brass seems to work fine for door knobs.

    • My local golf course (US Military owned) no longer takes cash as a form of payment. Cards only.

      • Then they need boycotting. We must fight for a cash alternative to be enshrined in law everywhere. Why? Reading some science fiction might help answer, but off the top of my head: privacy, doesn’t use energy to exist, still works when the lights go out, privacy, can’t be charged per transaction, doesn’t put victims of domestic violence in danger, allows people without banks to exist, privacy…

        • I wholeheartedly agree.
          I only pay in cash, and I refuse to go to places that does not accept cash.

          • I second that !
            Getting around London without a piece of plastic is now financially penalised by the public transport network.
            Another good reason to avoid the place as far as I’m concerned.

          • How do you manage that in Sweden? We’re the most cash avoiding country on earth.

          • By being extremely stubborn.
            And by never going into a place that do not accept cash.
            And on the day cash disappears I move.
            I flat out refuse that the entire world would know where the heck I buy an over-prised shot of espresso.

            The other option would be to have a credit card issued for a shell company in Northern Cyprus. Good luck to get any details out of that…
            NC Banks are the most secure banks on the planet, they are connected via Turkish banks, but all the registers are in NC, and to get to any of it the country asking for the details must first acknowledge NC as a country. And Turkey does not leave out squat since they just state that any country asking for details must ask the NC authorities, back to the acknowledge part.
            This has led to the bizarre situation where all intelligence agencies clear their cash through NC behind their own governments back.

          • Re the thread of wanting to pay cash. I recently had a run-in with our University bookstore. I was paying cash for a textbook and the clerk refused to sell it to me unless I “established an account” providing all sort of personal information. I really don’t want electronic records of individual book purchases archived in some system. I insisted on seeing a supervisor and they did have a mechanism to sell for cash and not keep a record. It disturbs me how most people accept this level of surveillance in the US. Books that are now sold openly and might be wanted by someone doing scholarly work or investigative journalism (Mein Kampf comes to mind) can trigger investigations and might cause problems down the road.

        • Military recreational facilities are typically run by the military exchange system.

          In my experience, these are some of the most nefarious retailers around. It was not uncommon for us to have to place students in financial counseling because the NEX pushed NEX credit cards on inexperienced young sailors who swiftly wound up strapped by the debt. NEX being closely affiliated with the military, was generally quite adept and quick to place a debt collection letter to the base disbursing offices.

          In my experienced opinion, the system is predatory in nature. Ostensibly they are supposed to provide a service to make normal retail goods affordable to the base population, not charging municipal sales tax due to their exemption status. But their prices are quite similar if not a bit higher than local retailers. The excuse is that the extra money goes towards other recreational offerings such as tours and such. In that respect, I can understand it, but they are in effect, not directly associated with the military and are in effect, just a commercial retail entity under contract to operate the system. I treat them with a wary eye whenever I use their services. Caveat Emptor.

        • What happens to electronic money when the power goes out?
          Why do people assume the power won’t ever go out?

      • I tried golf, once. On the Blue course at Pensacola NAS. After bouncing a drive through the base housing parking lot near the 9th hole I came to the conclusion that it wasn’t for me. (My parking lot ball was not as embarrassing as my cohort who bounced one down the middle of the main entrance road)

        Until that, I did not know golf balls were so springy when hitting asphalt.

        My only other golf experience was getting thrown off the course at Mayport Naval Station for inappropriate use of a golf cart. {I’m not the one that put it in the water} We WERE going to golf, but the buggy stunt cut that short.

        • Golf is a sport for auto-erotic masochists.

          You have a perfect set of round white balls to cherish.
          You then have to slowly acquire the skills to hit the ball with a bat instead of producing holes to plant potatoes in a highly manicured lawn.
          And as you finally hit your shiny balls, they end up in places where you can not find them again. More practicing with bat-fondling later, and you still end up with a ball that you for some mysterious reason have hit a few hundred metres away from your location.
          So, the poor saps that play this infernal game walk and walk and walk, until they can reacquire their balls. What do they do? Polish them and keep them? Noooo, they hit them again so that they can misplace them.

          So, golfers are basically people hating their balls, and that want to get rid of their balls in as tedious a fashion as possible.

  17. I am re-posting one of my last comments in the last article (it was posted shortly before the end of the comments, so it did not trigger any discussion, which I was hoping for!):

    First exoplanet discovered to contain water!


    Among already 4000+ exoplanets discovered, this is the first exoplanet confirmed to have a water atmosphere located in the habitable orbital region around the red dwarf star K2-18.

    The planet has a radius twice the Earth (so probably it’s a rocky planet) and is located about 0.15 AU from the star, so about half way the orbit of Mercury. So it could still mean extreme temperature variations on the planet or extreme radiation, but who knows… Scientists say that the planet may be also covered with a global ocean or an icy surface.

    I would guess volcanoes would place a big role in creating an atmosphere rich in water vapor.
    The rest of the atmosphere is apparently hydrogen and helium. Which is a bit weird as both gases escape smaller planets quite easily.

    The star located 111 light years ago shines at magnitude 13.5 in the constellation of Leo, so a good target for my 10 inch telescope…

    Being potentially a old star, it makes a perfect candidate for life detection.
    The next generation of space telescopes, to be launched in the 2020s, will allow a good chemical analysis of that planet (and many others). Scientists hope to find trace gases, that would be a signature of life (that can only be produced by life – that on itself is another big assumption).

    Exciting stuff!
    Any comments?

      • Events of the last couple of years have left me increasingly frustrated and bothered about the Webb telescope. The launch keeps getting pushed back. There are already slots booked to look at Jupiter and Mars, etc (which seem a total waste of this resource to me). And finally, the launch itself is, of course, a dangerous moment.

        Ground based telescope technology is surging forwards, and might even render the Webb telescope irrelevant. I do wish NASA would get a move on and launch it.

        • Well. There could be a bit of stage fright. Hubble’s optics turned into a huge embarrassment. With no means to conduct a repair. It has to be perfect first time around.

        • The launch money has been co-opted by a bully to build a space force.
          And without getting paid Musk does not lift it into space, quite simple.

        • Well, with the economic improvements here, we’ll get the funding together eventually. I’m more concerned about the USAF trying to co-opt the new agency. They have a reputation of trying to cut the throats of the other services.

        • JWST will not be rendered obsolete by ground-based observatories for one simple reason: the bands it observes at. The atmosphere is mostly opaque to those bands and so it is simply not possible for a ground-based telescope to do those observations at all.

    • Water will not be uncommon in such planets, at least the cooler ones. It is not far off from Uranus and Neptune which are ice giants. Bring one of those in to Mars’ orbit and you have pretty much what they saw, I think. Such ice giants may be the most common type of planet around.

  18. It feels very tempting to guess that one of the next VEI7 eruptions will be again in Indonesia (it might not be the next one, but perhaps one of the next 3)

    Rinjani in 1258 and Tambora in 1815 erupted within sight of each other, Both are located at 160km of each other. Krakatoa is a considerably further away, in Sumatra, and erupted in 1883.

    So, which Indonesian volcano will be the next big one?

    It needs to be a volcano with a high summit, and ideally near water.

    Agung jumps to me as one good candidate. As well as Semeru.

    Other ones: Merapi, Sindoro, Kerinci, Sinabung?

    • One that has had a few centuries of inactivity would help. That seems a consistent pattern between the recent largest explosions.

      • Iyang-Argapura, located in east Java, between Mt Bromo-Semeru and Ijen caldera, is a good candidate. Its close to Rinjani and Tambora (the last big ones in Holocene), it’s massive and tall, and it hasn’t erupted in a long time. Almost all nearby massive volcanoes in Java and Bali have calderas, except this one.

        Another candidate could be Mount Talakmau, another large volcano, this one in Sumatra, about 200km south from Toba, and also it hasn’t erupted in a long time.

        • So many volcanoes to choose from. Perhaps any that are over 3000 M.
          Raung is pretty active but it is quite tall.

          Rinjani might be dangerous. 1253 was a long time ago and there have been a lot of earthquakes around it of late.


        • Leonard Range on Mindanao seems to erupt every couple thousand years.

          • {snicker} Love it! 😀 😀 😀

            Many historians believe that the name Davao is the mixture of the three names that three different tribes, the earliest settlers in the region, had for the Davao River. The Manobos, an aboriginal tribe, referred to the Davao Rivers as Davohoho. Another tribe, the Bagobos, referred to the river as Davohaha, which means “fire”, while another tribe, the Guiangan tribe, called the river as Duhwow.

  19. I also read that Tamboras 1815 magma where a trachyte.
    That is basicaly an alkaline andesite
    But less alkaline than a phonolite.

    Large explosive and effusive alkaline eruptions are quite rare.
    These magmas are made in smaller ammounts than their subalkaline equalents.

    Its very odd how active Nyiragongo and Nyiramuragira are… despite they are on the very peak of alkalinity as alkaline as any sio2 based lava can get.
    Hardly any partial melting at all forms Nephelinite and Basanite… yet these two are hyperactive volcanoes.
    Nephelinite is probaly the sillicate magma thats made in smallest ammount

  20. ”Gliese 710 will trigger an observable cometary shower with a mean density of approximately ten observable comets every year, lasting for three to 4 million years,”
    wrote the astronomers on latest info om this subject

    Sounds very very dangerous with 4000 AU closest approach with 60% of suns mass: Defending against a massive asteroid / comet shower, because the star pulls them from their orbits, could prove to be a very difficult job for humanity to achieve.
    But it looks like in the distant future our descendants are in trouble Let’s hope they’ve got the means to survive anything it throws at them

    • Let’s put some numbers on this. The chance of randomly hitting the Earth when crossing this distance from the sun is 1.6 part in a billion. There is sonethign called ‘gravitational focussing’ which increases this but it depends on velocity: it is important for slow-moving objects (asteroids) but not for fast moving ones (Oort comets). You need to double the chance since the comet will cross our sun-distance twice. For ten comets per year, over 4 million years, the chance of hitting is 6%. Typical comet size will be 100 meters, and that would give a crater 2 km across. Over 4 million years, you get several such events anyway, mainly from (slow moving) asteroids.

      Oort comets come in from random directions as the cloud is almost spherical. Asteroids come in along the plane of the solar system so they have a much higher chance of hitting us.

      We should get some nice Tunguska events – again, those are common anyway. But I think there are more useful things to get worried about. No catastrophe here.

      • Tunguska-type events would be something to very, very much worry about if they happened over a densely populated area.

        An explosion of three to five megatons even located as high up in the atmosphere as Tunguska was would be absolutely devastating. Remember that Chelyabinsk was six times smaller than the low-end estimate for Tunguska and ten times smaller than the high-end estimate for Tunguska. Also remember that the air burst for Tunguska was estimated to have occurred at between five and 10 km high, rather than the 30 km of Chelyabinsk. Since blast wave power for an airburst goes as 1/r^3 (volume) that’s a pretty big attenuation due to the higher altitude of Chelyabinsk. A five km distance blast is 0.08, a 10 km distance blast is 0.001 and a 30 km blast is 0.000037 using 1/r^3 of those distances. So an explosion of a given size at five km produces a blast wave 27 times as powerful as an explosion of the same size at 10 km, and 216 times as powerful as an explosion at 30 km. If as has been suggested in some papers Tunguska effectively produced a “finger of doom”-shaped explosion then the volumetric attenuation of the blast wave would not go as 1/r^3, rather it would go as 1/hr^2, where h is the height of the explosion above the ground. Still I’m going to assume it’s a sphere for simplicity’s sake.

        Chelyabinsk essentially did no worse than shatter glass and cause injuries due to that (1,200 injuries of that type though). However if we compare Chelyabinsk of 500 kt at 30 km to the low end size of 3 Mt and high altitude estimates of Tunguska we have a shockwave six times larger due to size of event and 27 times larger due to distance, for a total greater shockwave power of 162 times (6*27). Worst case for Tunguska of high end size of 5 Mt and low altitude estimates we have a shockwave 10 times larger due to size of event and 216 times larger due to distance, for a total greater shockwave power of 2,160 (10*216).

        Shockwaves 162 or 2,160 times more powerful than Chelyabinsk would do an awful lot more than shatter windows. A Tunguska event over a city would essentially flatten a substantial section of that city. So although frequency of Tunguska-style events combined with chance of Tunguska-style events occurring over a city is fairly small, if it did happen it would be horrendous.

        Impact frequency for these type of events appears to be about once every 750 years or so, and with urbanised land area about 3% of earth’s landmass, and land being 29% of earth’s surface area, that means approximately 0.9% of earth’s total landmass is urbanised. An impact every 750 years or so with about a 1% chance of hitting an urban area produces one destroyed urban area approximately every 75,000 years.

        So in terms of frequency we are getting up towards VEI 8 volcanic eruptions. In terms of damage we are nowhere near VEI 8 volcanic eruptions.

        • This enforces the conclusion that the enhanced frequency of comets are not important, as such events are more common than one in a million years. Tunguska was an airburst. Their damage is limited to the area around the explosion. A ground impact which makes a crater of a few km across will damage a larger area but happens less often. Which type of events will cause most damage is not immediately obvious.

    • And since I am the only one planing to stick around as that time comes, I am not that worried about it. Byt then I plan to be happily uploaded into a neat star-travel capable ship.

      • One morality issue with the whole “uploading” idea, is that no one ever considers what becomes of the “source file” holder. This is something glossed over in Star Trek SciFi and other teleportation schemes and methods. The entity being copied or teleported has to undergo a horrendous death each time it happens or be subject to normal aging if they are left intact after being the source of the upload.

        And that is not even getting into the religious implications. The old “self” still exists or has to die. How do you accomplish that in a humane way? Theoretically, the new “self” will have all the memories of the former “self” right up until the moment of copying, depending on the level of detail in how you make the copy. If not, then the new “self” will start off ‘life’ as a mentally flawed entity. {Note, I’ve never seen the idea of cumulative copy errors discussed in any episode of Star Trek. Unless the teleportation system is absolutely perfect, there would be cumulative mental degradation for each and every teleport use.}

        On the religious side of things, does the new “self” have a soul? Does the phenomena of “Me” or “I” travel to the new “self?”

        • I think there is a transporter malfunction in one star trek – I have an idea that there end up being two Rikers with one having been left behind but one beamed aboard too – not 100% sure – but yes is it murder and birth each time they get beamed anywhere ?

        • I recall one episode where a crew member (shirt was not red) had a terror of the transporter. ‘Safest form of transport’ he was told. In the one case he was teleported, he found creatures in “no man’s land”. On grabbing one it turned out to be a ‘lost’ crew member or something.

          • That was Star Trek: The Next Generation “Realm of Fear”. The crew member who ended up rescuing others was Reginald Barclay, one of the engineers and a recurring character on TNG and Voyager. Which means, the only reason his shirt wasn’t red was because it was TNG where the engineers had changed to wearing yellow.

            On the other hand, being an engineer seems to save you, as Scotty repeatedly demonstrates, even repeatedly surviving being in landing parties.

        • With upload I did not mean the Star Trek teleportation, I mean continuously copying myself, and as and when my corporeal body dies, the digital copy will start to run on a suitable computer.
          That file in turn could be uploaded into any number of computers, say for instance into the control computer of a starship.
          And, why kill off one copy as you get a new one? The more mes the happier mes will bees.
          Now, imagine a billion mes galumphing about digitally 🙂

          And before anyone asks, yes I am aware that the download will not be 100 percent accurate. But, 80 percent is still a far cry better than the nothing of Death 1.0.

          And since I am about as religious as a door-knob I do not have any problem with seeing future uploaded mes as having both selves and a souls. I here obviously refer to Edward Fredkins ground breaking work in On the Soul.


          • I figure by the time Swift-Tuttle comes back or Long Valley Caldera blows I will either have been reincarnated or be somewhere in some spiritual afterlife capable of experiencing what is going on in the present through the senses and consciousness of a living being. I asked Miguel de Cervantes about this and he says, the latter, and you are not imagining things when the United States government in the second decade of the 20th century looks disturbingly like the Spanish Inquisition.

          • No idea where this will thread but thank you albert for reminding me about stanislaw Lem. A frequent contributor to analog and who came up with many excellent stories.

          • Lem at his best is brilliant. Some of his stories are parodies on life in Poland under communism.My favourite one is where his character has to reshape the past to make it more presentable, and gets every single thing wrong, ending up with exactly the same past but now it is all his fault. You can recognize communism. Of course it equally applies to the new US fad of false facts which also is trying to reshape the past. It wasn’t just a fault of communism.

          • Swift-Tuttle is 26 km across and goes at 60 km a second…
            Its more than two times larger than dinosaur impactor and goes twice as fast.

            This is the largest and one of the closest earth crossers, when it comes close. A tiny push from jupiter can throw it at collison course.

            A potential Swift Tuttle impact with two times more speed and almost 3 times more volume in mass .. will be 30 times more energy than chicxulub impact.. land sterilized.
            A tiny push from jupiter can end the age of mammals and vertebrates.

            But luckly Swift Tuttle is very predictable and safe for now : )
            The chance of impact is extremely small for now.

            The VC bar is better place for this impact thread

          • I think that the duplicate thing is rather depending on if you like yourself or not.
            I do though admit that talking to a fresh copy of mes might be a tad boring since neither of us would have anything fresh to impart on the conversation.
            A further separated mes could though be interesting if mes had done something that mes had not. Whoever now would be the mes is another question. 🙂

          • Physical schizophrenia beckons. Bipolar doesn’t begin to describe it.

          • Ref Carl’s 18:44;

            I think that your conversation with your freshly minted new “me” would be quite similar to a persons running internal dialog.

            A sort of related question… if you get pissed off at your new “me” and kill it… is it murder, or suicide? That would be an interesting court case.

            Over in fiction land, with the Kelvin timeline, there is a scene with Old Spock is departing Young Spock (due to a timeline screw up courtesy of the plot) where Old Spock declines making the usual “Live long and prosper” statement on the grounds that it would seem self serving.

          • I do not think that it will be described as a fractured mind, there would just be several regular minds. I think this will become commonplace for those who can afford the computer power to run several mes.
            It would also increase the likelihood of achieving true immortality.

          • I haven’t seen a set of batteries in any UPS go more than about five years or so… (APC™ or otherwise). On those that allegedly have, it takes a prybar to get them out… providing I don’t have to take the chassis apart to get them out of the system.

            Nothing lasts forever. Even Helka will be nothing more than a lump of dirt given enough time.

          • To geolurk on UPS batteries.

            I convert my old ones to run on external and much larger 12V ‘utility’ (ie can take constant charging) batteries. Cheaper, MUCH longer time delivering power and more recyclable.

            PS Keep insulated, often charger floats at 170VAC when charginf.

          • Side note: I hate floating references. One set of gear I used to do a monthly maint check on was for a 450 VDC supply voltage. You had to disable the HV system since ground reference floated at -10kV.


      • To deal with souch potential events
        I propose that humans move some socities and food production undeground ..
        living undeground and growing food without sunlight from nuclear sources or fusion electricity.

        That allows us to surivive a long dark Asteorid impact winter, when nothing can grow
        And at least a few ten thousands surivives

        • Mushrooms and grubs eh? Eloi will probably taste better.

        • Albert Im just curious
          Woud this help humanity survive something like a really large impact?
          I propose to move some cities and food prodcution underground, greens and maybe aquaculture, not depending on the sun, instead running on nulcear or fission. This coud be humans best shot on surviving a loong dark impact winter.

          Our modern way of life makes us very vulnerable indeed,
          if technology and food production goes out during an impact winter, most of humanity is paralysed.
          Very few can live an Ice Age existence anymore.

          99% of all species that ever exsisted have gone exctinict.. and humanitys future dont look promising if you look at most other species.

          But also this is also the first time since earths formation a species is so advanced and dominant as Homo sapiens is.
          We dont know how sucessful a modern advanced civilization really is, beacuse this is the first time on Earth a species attempts it.
          This is the first time on this planet a species becomes techonological
          There was NO earlier civilization on Earth… no geological layers that says that.

          • But at the same time, I doubt homo sapens woud survive IF a chicxulub like event or larger happened in the pleistocene…..
            caveman skills seems helpless

          • A matter of resilience. People depend on the eco system. The history of life on earth has been a history of interaction between living things and their environment wrote Carson in Silent Spring. If the environment is healthy, we can withstand some shocks. If it isn’t, we are more vulnerable. Some of the things we are doing are madness.

  21. Well here is an interesting observations. Volcanoes appear to cause long term stratospheric cooling after the intial haze driven shortwave warming. If you look a the trends https://www.climate.gov/news-features/understanding-climate/state-climate-2011-stratospheric-temperature
    The stratospheric temp drops to a lower level after the eruptions before becoming flat again. I suspect the injection of SO2 has long term effects on stratospheric chemistry by stripping H20 or O3. It should be also noted that a 5% decrease in cloud cover and eventually (post 98 el nino )a 2w/m2 increase in OLR occurred in the wake of Mt Pintatubo.

    Could volcanoes be driving climate more than realized?

    • Just no. The graph just shows the long term cooling effect caused by increasing greenhouse effect. Also, the lines are not flat, put together they show a significant cooling effect.

      Also, there is no strong variation in volcanic activity but a strong upwards trend in global temperatures, so just another try to deny anthropogenic global warming. Next try, please.

  22. Either an eruption or a large jökulhlaup has started at Grimsvötn at around 19.03 local time.
    We are awaiting confirmation.

  23. The main reason why Toba YTT did not seem to significantly disturb the global climate lies in the sulfur contents of the magma. The sulfur contents of YTT melt inclusions are at the detection limit (10-20 ppm), and they are not any higher than the sulfur contents of glass matrix (Chesner & Luhr, 2010) which means that YTT magma almost did not outgas any sulfur while erupting. On the other hand, Tambora has 690 ppm sulfur before eruption and difference of 400 ppm in terms of sulfur contents of melt inclusions and glass matrix (Self et al., 2004).

    Although pre-eruptive vapor phase is often regarded as the main source of volatile emissions in explosive silicic eruptions, such as Pinatubo or Huaynaputina, it might not be the case for Toba since thermodynamic calculations argue for very low sulfur content in vapor phase (Scaillet et al., 1998; Scaillet et al., 2003). Considering the amount of ejecta, the actual amount of outgassed sulfur was probably only comparable with Tambora in 1815.

    • We have looked at that in the past. Sulfur content is one aspect – but do realize the sheer size of Toba, so that even at low sulfur the total emission will still be huge. The second reason seems the be the low explosivity. This was largely a ‘fire’ eruption and the convection which carried the volatiles came from heat more than from explosions. The third reason is the eruption rate. At these high rates, the ash in the column gets too heavy and the column collapses. That also reduces the height of the ejecta. In the past there were reports of temperatures dropping by 10C worldwide, but that confused the ice age shortly after with the effects of the eruption.

      I think Toba had a massive impact on Earth, but as in all eruptions it was relatively short lived, a few years up to a decade. ‘Massive’ means a global temperature drop of may be a few degrees. It is hard to know, of course.

  24. Even considering the sheer size of YTT, it does not necessarily compensate the low sulfur content. YTT melt inclusions on average contain only 16 ppm sulfur, and glass matrix show that either none or very little of sulfur exsolved. Even if considering 25% of sulfur exsolved, the total released sulfur mass is only 2-3x of Pinatubo.

    I don’t think low explosivity can be really counted as a reason. Densely welded tuff (OTT and MTT) and rheomorphic ignimbrites (HDT), or any high-grade ignimbrite (Paraná–Etendeka ignimbrites), are indeed the products of moderately explosive pyroclastic fountaining, but for most of YTT the ignimbrites are nonwelded to incipiently welded which rather indicate the outflows were products of very energetic explosions and low temperature emplacement, and only the late-stage intracaldera ignimbrites are densely welded when the eruption became much less explosive and magma was less silicic. As much as 37% of magma was lost to form co-ignimbrite column with height reaching 30-50km during the emplacement of YTT flows based on vitric loss analysis which approximately equals the distal ash volume. Transportation of volatiles to stratosphere should not be a problem.

    • https://www.nature.com/articles/s41467-018-02901-0

      Movie 6 (supplementary material) is most appropriate to a ring fracture eruption. The ejecta reach 20-30 km but rather little goes higher than that. The paper claims that the plume reaches the mesosphere, but the movies suggest this is a very small fraction of the plume. The problem is that the sheer amount of ash gives a negative buoyancy above the eruption, so that the majority of the plume comes from the edges, not the centre.

      • Plume mass fractions in Costa et al. 2018 are quite model-dependent.
        Field evidence (Sparks & Walker, 1977) suggests on average as much as 35% of magma is elutriated out of the moving pumice flows by gas streaming through and up. The ash rises above the flows in an upper turbulent ash cloud. Because the ash particles are very fine-grained, there may be nearly 100% efficiency of conversion of heat to convective energy to drive the plumes and reach great heights. Such ash cloud can easily penetrate tropopause and be extremely extensive.
        37% vitric loss in YTT case is a minimal estimate because some loss of heavier crystals is even not considered and it rather explains the widespread of YTT tephra layer instead of falling back into pyroclastic flows before it reaches greater heights.

        • It is certainly model dependent but the basic problem of negative buoyancy is based on physics. Sparks & Walker find that small sh can rise above the plume and in fact Costa finds the same, but it does not say how far above – that is conjecture. From Costa I take that small fractions can rise to great heights, but I don’t see the evidence that this accounts for the majority of ash. The large amounts of Sparks & Walker are for the co-ignimbrite, and they do not calculate a height for those – in fact they present an idea, not a model. Costa’s models make these regions rise higher than the central plume but they do run into the same problem of limits to the weight that air can carry.

          Sulphate, of course, is a volatile and can decouple from the ash.

          • I mean it just makes more sense to me when the extensive spread of distal YTT tephras come from a high plume. The distal YTT ash volume is as high as 1000 km3 DRE and I would assume as much as 1000 km3 of fine ash was transported to above tropopause by the convective co-ignimbrite plume. It’s hard to imagine if the majority of elutriated ash stays under 20 km while the one-third of total eruptive product can still be so extensive.

          • Some of it certainly will have gone very high: the discussion is about the fraction rather than the location. But Toba also benefited from the tropical jetstream which is present in september and october. It acts at 8-10 km altitude, and goes directly from Indonesia to India (and on to Africa), which was indeed the direction the ash took (rather little was deposited in the opposite direction). Toba probably blew late september or there abouts, I expect. Krakatau did the same, while Tambora did not as the tropical jet does not operate n April.

  25. YTT eruption coincides with the start of MIS 5a/4 cooling based on 40Ar/39Ar dating. But when high-resolution (subdecadal to centennial) paleaclimate reconstructions are carrie out with YTT tephra layer as the stratigraphical marker, no volcanic winter or ecological turnover is seen on decadal scale (Huang et al., 2001; Schulz et al., 2002; Petraglia et al., 2012; Lane et al., 2013; Jackson et al., 2015; Yost et al., 2018; Smith et al., 2018).
    Also the catastrophe hypothesis is also invalidated since the population bottleneck is found to be actually founder effect as humans left Africa, not population decline (Li & Durbin, 2011).

    • The large VEI 8 pyroclastic eruptions like Toba and Yellowstone where fast and very very short lived

      Causing a dramatic very dramatic cooling for just a few years: these eruptions probaly did not impact the biosphere very much .. too short lived

      • The point here is that Toba apparently didn’t cause dramatic cooling, and the question is why. The claims for enormous cooling are unconvincing. Yellowstone is a different matter: it is too long ago to be able to pinpoint climate variations to sufficient accuracy to show (1) their magnitude, (2) their coincidence with the eruption. Even for Toba that is hard, go further back and it becomes impossible.

        • These types of large VEI8 blasts
          Where too short lived, to cause mass extinction

          Very severe effects .. but simply too short lived was La Garita and Toba

          • You don’t need to state the same comment twice: it was read.

            And it is not correct. You can’t get more ‘short-lived’ than Chicxulub. We can probably agree that this did have a severe impact on life.

          • Chicxulub Was much much much larger than any sillic VEI 8 eruption Albert : D

            Toba was 4000 km3 ejected

            Chicxulub was an volume 30 km deep and 170 to 190 km wide of volume of vaporized rock 3 to 5 times hotter than surface of the sun, ejected into the atmosphere.

            Im seconds the crust bounched up forming the central peak.
            The crater likely later was a molten sea of impact generated lava months after impact?

            Im soure Chicxulub had much much worse effects than the largest sillic tephra eruption.

            I have a question: how many km3 of materials was ejected during

          • Thank you Albert!
            And that suddenly does not sound large at all
            Just 20 times larger than Bishop Tuff in volume …

            But I knows the Reentering ejecta made hell on Earth
            Firestorm in the skies and dinosaurs cooked on the ground,
            wildfires everywhere.

            Chixlulub was also much much hotter than any VEI 8

            But wow just 20 000 km3 ?
            Thanks for your opinion.

            I underestimate the size of a VEI 8 explosive eruption! 😂
            Thats why 20 000 km3 seems small

          • Jesper, the firestorms concept is probably not correct as such.
            Yes, the energy release was large, and it contained a lot of heat, but probably not more than an equivalent sized eruption.
            The reason is simple, the really hot material from the asteroid itself was immediately plunged into the mantle with very little of the material being deposed in the atmosphere, and the crustal material would not have been hotter than a volcanic eruption, so at worst it would be the same average temperature as a regular pyroclastic flow.

            This was just studied for a very absurd reason. As NASA discovered Oumuamua, aka The Visitor, our dear army got it into their collective heads that it theoretically could have been a Very Fast Kinetic Impactor that had missed its intended target. So, they asked what the effect would have been if a similar sized iron-tungsten rod had hit earth at various high speeds.
            After having almost burned out a super-computer it turned out that the Science Fiction book that someone in the army had read was not even close to reality.
            Yes, the kinetic energy would be ridiculous. But the salient point was that most of the energy would have gone into the mantle directly, causing quite an earthquake, but not at any credible speed would it have caused the end of the planet.

            And before anyone asks, in July 2019 it was ruled that The Visitor was just an ordinary lump of space debris, and not any sort of alien contraption.

          • The firestorm theory coud very much be correct

            All the hot ejecta and vaporized rock sent into ballistic reentry trajectories…

            Hour after the impact trillions of tiny glass spheres reenters the atmosphere, heating things on the ground.

            KT boundary contains alot of soot from wildfires started by possible ejecta firestorm.
            North America was hit hardest by the reentering ejecta causing fires

            I apologize if I talks alot 🙂
            VC is a good place and removes some stress

          • Carl
            The Asteorid itself and the ground target competely melt and vaporize and is not buried in the ground …
            As it burrows into mantle the first second

            This forms a superhot ”rooster tail rock vapour plume” 5 times hotter than the surface of the sun that rise up from the impact togther with ejecta.

            Thats why the iridrium is found world-wide in KT boundary deposits. The Asteorid and ground rock vaporized and spread across the globe.

            As far as I know …
            Your opinion is intresting too 🙂

          • It definitely did not vaporize entirely. The time in crust is just to short.

            To make an analogy Jesper, imagine shooting a bullet into a very large foam-ball that has been dunked into chocolate forming a thin layer (chocolate being the crust).

            The bullet would be very hot as it hit the chocolate layer, it would locally turn the chocolate into dust with a very minute copper content from the bullet. But, the vast majority of the bullet would end up lodged in the foam part of the ball.

            I will try to explain the physics behind it a bit better.
            First you must understand directional energy. All of the energy is directed straight down (almost straight down in this case).
            So, the energy and the impactor material will punch downwards like the above mentioned bullet.
            At the same time you have displacement causing an upwards plume of displaced material (your basic crust mostly, but with a bit of mantle chucked in for good measure).
            Now, almost the same amount of energy will go upwards, and the energy will be in the form of displaced material and not that much heat. That is why you have more material gouged out than the volume of the impactor.

            We do know this from drill samples from other big impacts. Not far from you is Siljan, the bulk of the impactor traces start at 2km down. We know this since some dimwit convinced a lot of investors that there should be natural gas down there… obviously there was none.

            So, opinion? Not so much.

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