In mid-April 2010, over a number of days jet aircraft were grounded throughout Europe as a safety precaution because of potential damage to aircraft engines from clouds of volcanic ash sweeping over Europe. Around 1,000 flights were cancelled affecting 8 million passengers. The cost to the airline industry alone was estimated at near two billion dollars. Freight movements were also severely disrupted causing large losses and inconvenience to both importers and exporters.

The ash was coming from the Eyjafjallajökull volcano in Iceland, and being carried over Europe by the prevailing winds. Till the eruption which started on 20 March 2010, this volcano had been dormant for almost 200 years, the last eruption commencing in December, 1821 and continuing till January, 1823.

Although this latest eruption was small in comparison to previous eruptions in Iceland and other places, it became significant because of the large amount and type of ash emitted, it being very damaging to jet aircraft engines, windscreens and light coverings. Thus for safety reasons planes were not permitted to fly.

But what if the larger and more dangerous Katla volcano had erupted? This volcano which is near the Eyjafjallajökull volcano, and is similar in that it sits under a glacier and should eruptions start will melt the ice and cause explosions, ejecting huge amount of fine glass type ash and toxic gases into the atmosphere. In the past Katla has often sprung to life soon after eruptions at the Eyjafjallajökull volcano, but with greater and longer emissions. Some scientists have predicted that should this occur, aircraft movements in Europe could be disrupted for up to five months, causing worldwide travel chaos and drastic effects to the world economy.

Large volcanic eruptions have periodically occurred throughout the world resulting in much loss of life and property and on occasions affecting climate and food production.

The eruption of the Laki volcano Iceland, in 1783 had drastic consequences and is estimated to have caused the death of two million people worldwide, mostly due to famine. Vulcanologists consider it to be the second-largest eruption in the last 1,000 years and the most deadly.

With ash and toxic gases from Laki being ejected into both the troposphere and the higher stratosphere, climate effects in the near term and longer term occurred. Volcanic material which does not go beyond the troposphere tends to come back to earth in days or weeks. However material that reaches the stratosphere, which commences over Iceland at around 15 kilometres, can remain aloft for several years and has the effect of reflecting back sunlight and reducing temperatures. The stratosphere currents run in an east to west direction whereas wind currents in the lower atmosphere can travel in various directions.

The Laki eruption commenced at 9.00am on Sunday, 8 June 1783 and continued for eight months until 7 February 1784. Fissures progressively opened up along a 17 mile (27km) line and by the end of the eruption some 130 separate volcanic cones ranging in height from 40m to 70m, could be found along the fissure line At the same time of this eruption a second nearby volcano, Grimsvotn, was also erupting, and was active from 1783 to 1785. Eye witnesses say that fountains of fire from the Laki eruption shot almost a mile into the atmosphere. Some 3.4 cubic miles of basalt lava flowed from these cones and covered an area of 500 square kilometres. It is further estimated that 120 million tons of toxic gases were flung into the atmosphere, mostly hydrofluoric acid and sulphur dioxide mixed with fine sand.

Much of this ash fell on Iceland but a considerable quantity was carried by prevailing winds across Europe and beyond. The effects at Iceland and Europe were devastating, killing vegetation, live stock and people.

In Iceland the toll on livestock was enormous, killing 80% of the sheep, 50% of the cattle and 50% of the horses. This was due to the loss of feed and the effects of hydrogen fluoride poising causing dental and skeletal fluorosis. This coupled with the loss of crops led to famine, resulting in the death of around 10,000 people or 25% of the islands population of 50,000 people.

An eye witness record of the event was written by the parish priest of the settlement of Kirkjubæjarklaustur which was close to the eruption. The Reverend Jon Steingrimsson wrote “This past week and the two prior to it, more poison fell from the sky than words can describe: ash, volcanic hairs, rain full of sulphur and saltpetre, all of it mixed with sand. The snouts, nostrils, and feet of livestock grazing or walking on the grass turned bright yellow and raw. All water went tepid and light blue in colour and gravel slides turned grey. All the earth’s plants burned, withered or turned grey, one after another, as the fire increased and neared the settlements”.

Europe

In Europe the summer of 1783 was the hottest on record, generally believed to have been due to a major El Niño event resulting in a rare high-pressure zone over Iceland, causing the winds to blow to the south-east.  The poisonous cloud firstly reached Bergen in Norway, then spread to Prague by 17 June, Berlin by 18 June, Paris by 20 June, Le Havre by 22 June and to Great Britain by 23 June.

The fog was so thick that boats stayed in port, unable to navigate, and the sun was described as blood coloured. So unusual and dramatic was the summer that it came to be known as “the sand summer.”

The weather became very hot, causing severe thunderstorms and large hailstones that are reported to have killed cattle and destroyed crops until the fog dissipated in the autumn. This was followed by a most severe winter in 1784. 

Benjamin Franklin when he was Ambassador in France in 1783 noted the fog in his writings describing it as a thick dry fog.

One Parish priest in France wrote that one third of the men of his parish were “swept to their tombs.” With the people of the time being greatly alarmed and believing that the fog and deaths were due to evil spirits, forced their priest to perform an exorcism ceremony on the clouds.

The cause of these deaths is now known, the result of sulphur dioxide particles being indigested into the lungs and on encountering moisture there, converting to sulphuric acid causing tissues to swell, resulting in suffocation. This was the reason why the death rate for outdoor rural workers was higher than for people who were mostly indoors.

Several people recorded the events of the time. The Reverend Gilbert White who lived at Selborne, Hampshire, England wrote. “The summer of the year 1783 was an amazing and portentous one, and full of horrible phaenomena; for besides the alarming meteors and tumendous thunderstorms that affrightened and distressed the different counties of this kingdom, the peculiar haze, or smokey fog, that prevailed for many weeks in this island, and in every part of Europe, and even beyond its limits, was a most extraordinary appearance, unlike anything known within the memory of man. By my journal I find that I had noticed this strange occurrence from June 23 to July 20 inclusive, during which period the wind varied to every quarter without making any alteration in the air. The sun at noon, looked as blank as a clouded moon, and shed a rust-coloured ferruginous light on the ground, and floors of rooms; but was particularly lurid and blood-coloured at rising and setting. All the time the heat was so intense that butcher’s meat could hardly be eaten on the day after it was killed; and the flies swarmed so in the lanes and hedges that they rendered the horses half frantic, and riding irksome. The country people began to look, with superstitious awe, at the red, louring aspect of the sun.”

In another report of the time the Reverend Sir John Cullum of Bury St. Edmunds, Suffolk recorded on the 23 June, the same date that Gilbert White noted the beginning of the unusual atmospheric phenomena, in a letter to Sir Joseph Banks, then President of the Royal Society ………….. “about six o’clock that morning, I observed the air very much condensed in my chamber-window; and upon getting up, was informed by a tenant that finding himself cold in bed, about 3 o’clock in the morning, he looked out his window, and to his great surprise saw the ground covered with white frost: and I was assured that two men at Barton, about three miles (5 km) off, saw in some shallow tubs, ice of a thickness of a crown-piece”

Sir John goes on to describe the effect of this ‘frost’ on trees and crops: “The aristae of the barley, which was coming into ear, became brown and withered at their extremities, as did the leaves of the oats: the rye had the appearance of being mildewed: so that the farmers were alarmed for those crops….The larch, Weymouth pine, and hardy Scotch fir, had the tips of their leaves withered’. Sir John’s vegetable garden did not escape; he noted that the plants looked ‘exactly as if a fire had been lighted near them, that had shrivelled and discoloured their leaves’.

In Great Britain, the summer of 1783 was known as the ‘sand summer’ due to ash fallout, with the month of July being the equal warmest month in 300 years of records for the U.K.

The death rate in the U.K. during that summer was greater than average, mostly outdoor workers; the death rate in Bedfordshire, Lincolnshire and the east coast was thought to be two or three times the normal rate. It is estimated that 23,000 British people died from the poisoning.

The hot summer was followed by a very severe winter, the most severe for 250 years. Gilbert White at Selborne, Hampshire, reported 28 days of continuous frosts. The extreme winter in 1784 is estimated to have caused 8,000 additional deaths in the U.K. The following winter in 1784-85 was also cold, while the summer of 1784 was cool.

Effects in Africa and Asia

It is believed the Laki eruption caused climate change over northern Africa, India and Japan. resulting in low rainfall, drought and famine. Computer modelling suggests that the Laki eruption caused a weak monsoon – the seasonal winds that bring the annual rains to northern Africa and southern Asia. The unusual cold in the North lessened the temperature contrast between the land and the oceans, upon which the monsoon winds rely for their development and strength.

The modelling showed significant warming that occurred in the region west to east across Africa to the southern Arabian Peninsular and on to India during the summer of 1783. With little or no monsoon, there were no clouds to bring rain for the rivers or shield the surface from evaporation. Little or no rain, no irrigating floods, no crops and no food – all conspired to bring about famine and death.

Laki’s far flung effects were chronicled by the French scholar, Constantin Volney and his friend Benjamin Franklin. Volney recorded, “The (annual Nile) inundation of 1783 was not sufficient, great part of the lands therefore could not be sown for want of being watered, and another part was in the same predicament for the want of seed. In 1784, the Nile did again not rise to the favourable height, and the dearth immediately became excessive. Soon after the end of November, the famine carried off, at Cairo, nearly as many as the plague.”

During the same year of 1783 Japan experienced its worst famine ever recorded known as the ‘Tenmei famine’.

Effects in North America

During 1783 blood red sunrises were noted over North America with the summer of that year being cold. The evidence from tree rings suggests that the summer was the coolest in the previous 400 years. The Inuit Indians knew the time as ‘the summer that did not come’.

In the eastern North America, the inter of 1783-84 was the longest and one of the coldest in American history. It was the longest period of below zero temperature in New England, the largest accumulation of snow in New Jersey, the longest freezing over of the Chesapeake Bay. There was ice skating in Charleston Harbour, a huge snowstorm hit the south, the Mississippi River at New Orleans froze over, and there were even ice flows in the Gulf of Mexico.

Originally written by Ivan Badcock in June 2010