Laki or Lakagígar is a volcanic fissure in the south of Iceland, not far from
the canyon of Eldgjá and the small village of Kirkjubæjarklaustur.
Lakagígar is the correct name, as Laki mountain itself did not erupt, as
fissures opened up on each side of it. Lakagígar is part of a volcanic system
centered on the Grímsvötn volcano and including the Þórðarhyrna volcano. It
lies between the glaciers of Mýrdalsjökull and Vatnajökull, in an
area of fissures that run in a southwest to northeast direction.
The system erupted over an eight-month period between 1783 and 1784 from the
Laki fissure and the adjoining Grímsvötn volcano, pouring out an estimated 14 km3
of basalt lava and clouds of poisonous hydrofluoric acid and sulfur dioxide
compounds that killed over 50% of Iceland's livestock population, leading
to a famine which then killed approximately 25% of the island's human
population. The Laki eruption and its aftermath
caused a drop in global temperatures, as sulfur dioxide was spewed into the
Northern Hemisphere. This caused crop failures in Europe and may have caused
droughts in India. The eruption has been estimated to have killed over six
million people globally, making it the deadliest in historical times.
1783 eruption On 8 June 1783, a fissure with 130
craters opened with phreatomagmatic explosions because of the groundwater
interacting with the rising basalt magma. Over a few days the eruptions
became less explosive, Strombolian, and later Hawaiian in character, with high
rates of lava effusion. This event is rated as 6 on the Volcanic Explosivity
Index, but the eight-month emission of sulfuric aerosols resulted in one of the
most important climatic and socially repercussive events of the last
millennium. The eruption, also known as the
Skaftáreldar or Síðueldur, produced an estimated 14 km3 of basalt lava, and the
total volume of tephra emitted was 0.91 km3. Lava fountains were estimated to
have reached heights of 800 to 1,400 m. The gases were carried by the convective
eruption column to altitudes of about 15 km.
The eruption continued until 7 February 1784, but most of the lava was ejected
in the first five months. Grímsvötn volcano, from which the Laki fissure
extends, was also erupting at the time, from 1783 until 1785. The outpouring of
gases, including an estimated 8 million tons of hydrogen fluoride and an
estimated 120 million tons of sulfur dioxide, gave rise to what has since
become known as the "Laki haze" across Europe.
= Consequences in Iceland= The consequences for Iceland, known as
the "Móðuharðindin", were catastrophic. An estimated 20–25% of the population
died in the famine and fluoride poisoning after the fissure eruptions
ensued. Around 80% of sheep, 50% of cattle and 50% of horses died because of
dental fluorosis and skeletal fluorosis from the 8 million tons of hydrogen
fluoride that were released. The parish priest and dean of
Vestur-Skaftafellssýsla, Jón Steingrímsson, grew famous because of
the eldmessa that he delivered on 20 July 1783. The people of the small
settlement of Kirkjubæjarklaustur were worshipping while the village was
endangered by a lava stream, which ceased to flow not far from town, with
the townsfolk still in church. "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 sulfur and saltpeter, 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 color and gravel slides
turned gray. All the earth's plants burned, withered and turned gray, one
after another, as the fire increased and neared the settlements."
= Consequences in monsoon regions= There is evidence that the Laki eruption
weakened African and Indian monsoon circulations, leading to between 1 and 3
millimetres less daily precipitation than normal over the Sahel of Africa,
resulting in, among other effects, low flow in the River Nile. The resulting
famine that afflicted Egypt in 1784 cost it roughly one-sixth of its population.
The eruption was also found to have affected the southern Arabian Peninsula
and India. = Consequences in Europe=
An estimated 120,000,000 long tons of sulphur dioxide was emitted, about three
times the total annual European industrial output in 2006, and
equivalent to six times the total 1991 Mount Pinatubo eruption. This outpouring
of sulphur dioxide during unusual weather conditions caused a thick haze
to spread across western Europe, resulting in many thousands of deaths
throughout 1783 and the winter of 1784. The summer of 1783 was the hottest on
record and a rare high-pressure zone over Iceland caused the winds to blow to
the south-east. The poisonous cloud drifted to Bergen in Denmark–Norway,
then spread to Prague in the Kingdom of Bohemia by 17 June, Berlin by 18 June,
Paris by 20 June, Le Havre by 22 June, and 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". Inhaling sulphur dioxide gas causes
victims to choke as their internal soft tissue swells – the gas reacts with the
moisture in lungs and produces sulfurous acid. The local death rate in Chartres
was up by 5% during August and September, with more than 40 dead. In
Great Britain, the records show that the additional deaths were among outdoor
workers; the death rate in Bedfordshire, Lincolnshire and the east coast was
perhaps two or three times the normal rate. It has been estimated that 23,000
British people died from the poisoning. The weather became very hot, causing
severe thunderstorms with large hailstones that were reported to have
killed cattle, until the haze dissipated in the autumn. The winter of 1783/1784
was very severe; the naturalist Gilbert White in Selborne, Hampshire, reported
28 days of continuous frost. The extreme winter is estimated to have caused 8,000
additional deaths in the UK. During the spring thaw, Germany and Central Europe
reported severe flood damage. The meteorological impact of Laki
continued, contributing significantly to several years of extreme weather in
Europe. In France, the sequence of extreme weather events included a
surplus harvest in 1785 that caused poverty for rural workers, as well as
droughts, bad winters and summers, and a violent hailstorm in 1788 that destroyed
crops. These events contributed significantly to an increase in poverty
and famine that may have contributed to the French Revolution in 1789. Laki was
only one factor in a decade of climatic disruption, as Grímsvötn was erupting
from 1783 to 1785, and there may have been an unusually strong El Niño effect
from 1789 to 1793. = Consequences in North America=
In North America, the winter of 1784 was the longest and one of the coldest on
record. It was the longest period of below-zero temperatures in New England,
with the largest accumulation of snow in New Jersey, and the longest freezing
over of the Chesapeake Bay, where Annapolis, Maryland, then the capital of
the United States, is located; the weather delayed Congressmen in coming to
Annapolis to vote for the Treaty of Paris, which would end the American
Revolutionary War. A huge snowstorm hit the south, the Mississippi River froze
at New Orleans and there was ice in the Gulf of Mexico.
= Contemporary reports= Gilbert White recorded his perceptions
of the event at Selborne, Hampshire, England:
The summer of the year 1783 was an amazing and portentous one, and full of
horrible phaenomena; for besides the alarming meteors and tremendous
thunder-storms that affrighted 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 butchers' 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 a superstitious awe, at
the red, louring aspect of the sun; [...]
Benjamin Franklin recorded his observations in a 1784 lecture:
During several of the summer months of the year 1783, when the effect of the
sun's rays to heat the earth in these northern regions should have been
greater, there existed a constant fog over all Europe, and a great part of
North America. This fog was of a permanent nature; it was dry, and the
rays of the sun seemed to have little effect towards dissipating it, as they
easily do a moist fog, arising from water. They were indeed rendered so
faint in passing through it, that when collected in the focus of a burning
glass they would scarce kindle brown paper. Of course, their summer effect in
heating the Earth was exceedingly diminished. Hence the surface was early
frozen. Hence the first snows remained on it unmelted, and received continual
additions. Hence the air was more chilled, and the winds more severely
cold. Hence perhaps the winter of 1783–4 was more severe than any that had
happened for many years. The cause of this universal fog is not
yet ascertained [...] or whether it was the vast quantity of smoke, long
continuing, to issue during the summer from Hekla in Iceland, and that other
volcano which arose out of the sea near that island, which smoke might be spread
by various winds, over the northern part of the world, is yet uncertain. to the
east and the Grímsvötn volcano was erupting about 75 miles north east.
Additionally Katla, only 31 miles south east, was still renowned after its
spectacular eruption 28 years earlier in 1755.)
Sir John Cullum of Bury St Edmunds, Suffolk, England, recorded his
observations on 23 June 1783, 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 three o’clock
in the morning, he looked out at his window, and to his great surprise saw
the ground covered with a white frost: and I was assured that two men at
Barton, about 3 miles off, saw in some shallow tubs, ice of the 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.’ See also
References Further reading
Brayshay, M and Grattan, J. "Environmental and social responses in
Europe to the 1783 eruption of the Laki fissure volcano in Iceland: a
consideration of contemporary documentary evidence" in Firth, C. R.
and McGuire, W. J. Volcanoes in the Quaternary. Geological Society, London,
Special Publication 161, 173–187, 1999 Chris Caseldine. Iceland: Modern
Processes And Past Environments. Elsevier. ISBN 978-0-444-50652-8.
Grattan, J., Brayshay, M. and Sadler, J. "Modelling the distal impacts of past
volcanic gas emissions: Evidence of Europe-wide environmental impacts from
gases emitted during the eruption of Italian and Icelandic volcanoes in 1783"
in Quaternaire, 9, 25–35. 1998. Grattan, D., Schütenhelm, R. and
Brayshay, M. "Volcanic gases, environmental crises and social
response" in Grattan, J. and Torrence, R. Natural Disasters and Cultural
Change, Routledge, London 87–106. 2002. Grattan, J.P. and Brayshay, M.B. "An
Amazing and Portentous summer: Environmental and social responses in
Britain to the 1783 eruption of an Iceland Volcano" in The Geographical
Journal 161(2), 125–134. 1995. Richard B. Stothers. "The great dry fog
of 1783" in Climatic Change, 32, 79–89, 1996.
"The Summer of Acid Rain", Economist, December 19, 2007.
Thorvaldur Thordarson and Stephen Self. "Atmospheric and environmental effects
of the 1783–1784 Laki eruption; a review and reassessment" in J. Geophys. Res.,
108, D1, 4011, doi:10.1029/2001JD002042, 2003.
Witze, Alexandra and Jeff Kanipe. Island on Fire: The Extraordinary Story of
Laki, the Volcano That Turned Eighteenth-Century Europe Dark. Profile
Books, 2014. ISBN 9781781250044. External links
Photos and information Information about the volcanism at Laki
Lakagígar A meditation on Jón Steingrímsson from
Anglicans Online Dr John Grattan at International
Volcanic Heath Hazard Network A Sulphurous Stench: Illness and Death
in Europe Following the Eruption of the Laki Fissure
The Dry Fog of 1783: Environmental Impact and Human Reaction to the
Lakagígar Eruption