Part 5 of  PhD student Geoff Hellman’s in depth study of the eruption of the Laki volcano and the effects it had worldwide. He has kindly allowed us to publish some of his writing.

The long winter of 1783-1784 

The Northampton Mercury Jan. 12 printed the following reports:

“The Frost was never known in the Memory of Man so severe as on Tuesday and Wednesday last. The Severn was frozen over for Miles together, and various are the Accounts of the People and Cattle that perished. Last Week, during the severe Weather, the Post-boy from Dumfries to Thornhill was found frozen to death upon his Horse.”

And on the 23^rd of February the same paper published a letter concerning the weather conditions in North Wales which stated that:

“The oldest Man living does not remember such a Fall of Snow in those Parts as they have had this Winter. In many Places it is 12 Feet (3.66 m.) deep, so that they have been obliged to house all their Cattle, and the Roads are rendered almost impassable.”

The Gentleman’s Magazine reported that on the 30^th of January “A man walked across the River Thames, on the ice, at low water, from Rotherhithe to Wapping new stairs.”In York, the River Ouse “was frozen so firmly, that during eight successive weeks, it was frequented by the most timid with the utmost confidence”

The majority of canals in Flanders were frozen over shortly after the 20^th of December and remained so until the end of February and beginning of March when the thaw set in. According to Blomme, at Dendermonde in east Flanders the frost lasted from the 8^th of December until the 21^st of February, and the River Scheldt was frozen over from 18^th of December and opened up again on the 25^th of February. There were freezing temperatures for the whole of March thus making for a late spring.

Flood marks of the River Elbe, Castle Rock, Děčín (View of the castle rock in Děčín showing high water marks for R. Elbe (photo J. Kašpárek)

However, once the thaw started it was very rapid. The huge quantities of ice and snow that had built up over the winter melted rapidly, filling the rivers with so much water that they were unable to cope with removing it, thus bursting their banks, and flooding the neighbouring towns and villages. The following report gives a graphic description of the flooding that took place around the town of Louvain, in the Scheldt catchment area:

“Due to abundant snow that had fallen in and around the Walloon Brabant, when the thaw set in on the 21^st (February), the water and snow could not soak away, making our rivers swollen beyond description, and flooding nearly the whole town. It started around midnight of the 23^rd to the 24^th of this month, while everybody was fast asleep; shouting and yelling to one another, everybody in danger of his life tried to save himself (by going) to the second floor and attic of his house. It was horrible; at 10 o’clock in the morning of the 24^th, what a level the waters have reached…Outside and within the Canal Gate, as far as the eye could see: nothing other than water. Like the River Dijle, which seriously overflowed its banks on all sides, the River Voer did the same. In short, the whole Lower Town was flooded; there was no street that was not like a stream.(Lovens-Nieuws, no 9, Sondag 29 Februarii 1784, pp. 130-131)”

The long winter of 1783-1784 affected not only Europe, but also the eastern United States, where it has been described as one of the three worst winters during the 18^th century, the others being 1740-1741 and 1779-1780. The winter began in mid-November and lasted until spring, during which time Chesapeake Bay was iced over, thus closing many channels and harbours; the Mississippi River was frozen over at New Orleans between 13^th and 19^th of February, and after the ice had melted, the river was inundated with broken ice, floes reaching as far as the Gulf of Mexico some 100 kilometres to the south. The period from December 1783 to February 1784 saw the lowest winter average temperature of -3.8°C, ever recorded. This is 4.8°C lower than the 225 year average.

In order to emphasize the harshness of the winter during 1783-1784 in the eastern United States, Ludlum, 1966, compiled the following records:

• Longest in early American history (last snow in late April),
• Near record depth of snow cover,
• Near record low temperatures
• Greatest seasonal snowfall ever in New Jersey
• Longest period of below zero temperatures ever in New England
• Longest freezing ever of Chesapeake Bay,
• Longest and coldest winter in Maine
• Freezing of Charleston Harbour (ice skating occurred),
• Freezing of Mississippi River in New Orleans,
• Ice floes in Gulf of Mexico 100 km south of New Orleans.

The cold winter also caused ice bridges to form over the St. Lawrence River near Quebec City, Canada during the years 1784, 1785 and 1787. For some, however, the long cold winter began in the early summer of 1783. Inuit legends chronicle the story  of the Kauwerak people living in extreme northwest Alaska some 5000 kilometres from Quebec, which tell of a disastrous summer of extreme cold, famine, deserted villages and death; this led to it being called, “the summer that did not come”. The legends have been backed up by Alaskan tree ring data that seem to point to a Laki connection. Nevertheless, despite this evidence, the effect of the Laki eruption on the climate of North America remains controversial.

The question that now arises is whether the Laki eruption was the driving force behind the severity of the 1783-1784 winter, or if there was some other reason. Benjamin Franklin writing in 1784 certainly thought that the eruption was to blame. This idea was generally accepted until a paper by D’Arrigo et al, 2011, convincingly suggested that the extreme harshness of the winter was caused by a combined negative phase of the North Atlantic Oscillation (NAO) and an El Niño-Southern Oscillation (ENSO) warm event, a situation which also occurred during the winter of 2009-2010.

However, various authors had already begun to query the role played by Laki in causing this bad weather. Sadler and Grattan, 1999, concluded that: “There is little doubt that volcanic activity has a climatic effect but the historical temperature record indicates a surface cooling that in most cases falls within expected annual variation,” and Brazdil et al, 2009, were of the opinion that: “The winter 1783-1784 can be taken as a typical, if severe, winter during the ‘Little Ice Age’”.

Conclusion

Iceland showing the North American and Eurasian plates and main volcanoes

In this series of articles I have reviewed the geology of Iceland and placed Laki within this context. The eruption of 1783-1784, which was the second largest basaltic lava flow in recorded history, proved catastrophic, killing the majority of the island’s livestock, mainly through chronic fluorosis, and over 20% of the population through starvation; it also left its mark over most of the Northern Hemisphere.

Writing in his journal, Gilbert White said that “The summer of the year 1783 was an amazing and portentous one, and full of horrible phenomena”. The beginning of February saw a two-month long period of devastating earthquakes in Sicily and southern Italy which killed an estimated 35,000 to 50,000 people and destroyed many towns and villages. In the second half of the year, minor quakes and tremors occurred in France, the Low Countries, Germany and Switzerland. Unfortunately, the misery of the Calabrian earthquakes was compounded by eruptions of Etna, Stromboli and Vulcano during the second half of February. There was also more volcanic activity in Iceland, with the short-lived Island of Nýey being formed by a submarine eruption during the early part of the year.

Locations and timing of the first appearance of the Laki haze in June 1783 in Europe (Thordarson & Self (2003))

Perhaps the most notable effect of the Laki eruption was the appearance of the hot, dry, sulphurous fog which spread over much of the northern hemisphere from North America in the West, to China in the East. It made the eyes smart, triggered headaches, and caused considerable suffering to asthmatics and those suffering from other bronchial complaints. In places, crops were damaged either by acid rain or acid volatiles in the fog. There were heatwaves throughout northern and western Europe, but a bitterly cold summer over the eastern North American seaboard. Not all the effects were bad, however, as record harvests were reported from eastern and southern Europe. One strange effect was to make the sun appear blood red owing to the density of the haze.

From July to September the fog was accompanied by violent storms with much thunder and lightning, hurricane force winds, driving rain and the occasional fireball. From all over Europe there were reports of loss of life and structural damage to a great many buildings. Inevitably, the general public were extremely worried by these events, so much so in fact, that the French astronomer, de la Lande, was induced to write a letter, which was widely published in Britain and France, emphasising the fact that these phenomena were not so unusual after all. Gennari, writing from Padua said the same reassurances were being made in Italy.

The winter of 1783-1784 proved to be long and hard with record snow falls and low temperatures in many places. The River Thames in London was frozen over, as were the Dutch canals, and many European rivers. When the thaw came, rivers burst their banks through being overburdened with melted snow and ice which was unable to soak away due to the frozen or waterlogged ground: there was severe flooding in many places which caused great distress for the people.

According to Brazdil et al, 2009, “The floods during the winter 1783/1784 are the most spectacular covered by instrumental and documentary data at the broader European scale and provide a valuable insight into the severity and magnitude of such events.” In this connection we have looked at the epigraphic markers that were used to record these events and can see that they are useful even today to compare recent flooding with past and possible future inundations. To quote Brazdil, “Learning from past events remains an important step in better understanding and providing more effective protective measures for possible future events”.

Finally, it would appear that Franklin and other commentators may have been incorrect in ascribing the severe winter conditions in 1783-1784 to the Laki eruptions. There had been disquiet about this theory for some time, but the matter now seems to have been resolved by D’Arrigo et al, who suggest that the conditions were most likely caused by a combined negative phase of the North Atlantic Oscillation and an El Niño-Southern Oscillation warm event.

The Orkney News would like to thank Geoff Hellman for contributing this series of articles to our paper. This is what community based not for profit media is about and we wish him all the best for his studies.