Product Code Database
Laki () or Lakagígar (, Craters of Laki) is a Fissure vent in the western part of Vatnajökull National Park, Iceland, not far from the volcanic fissure of Eldgjá and the small village of Kirkjubæjarklaustur. The fissure is properly referred to as Lakagígar, while Laki is a mountain that the fissure bisects. Lakagígar is part of a volcanic system centered on the volcano Grímsvötn and including the volcano Þórðarhyrna. It lies between the of Mýrdalsjökull and Vatnajökull, in an area of fissures that run in a southwest to northeast direction.
The system erupted violently over an eight-month period between June 1783 and February 1784 from the Laki fissure and the adjoining volcano Grímsvötn. It poured out an estimated 42 billion tonnes or of basalt lava as well as clouds of poisonous hydrofluoric acid and sulfur dioxide compounds that contaminated the soil, leading to the death of over 50% of Iceland's livestock population, and the destruction of the vast majority of all crops. This led to a famine which then killed at least a fifth of the island's human population, although some have claimed a quarter.Gunnar Karlsson (2000), Iceland's 1100 Years, p. 181.
The Laki eruption and its aftermath caused a drop in global temperatures, as 120 million tonnes of sulfur dioxide was spewed into the Northern Hemisphere. This caused crop failures in Europe and may have caused droughts in North Africa and India.
The eruption, also known as the Skaftáreldar ("Skaftá fires") or Síðueldur produced an estimated of basalt lava, and the total volume of tephra emitted was . were estimated to have reached heights of . The gases were carried by the convective eruption column to altitudes of about .
The eruption continued until 7 February 1784, but most of the lava was ejected in the first five months. One study states that the event "occurred as ten pulses of activity, each starting with a short-lived explosive phase followed by a long-lived period of fire-fountaining". Grímsvötn volcano, from which the Laki fissure extends, also erupted at the time, from 1783 until 1785. The outpouring of gases, including an estimated 8 million tonnes of fluorine and an estimated 120 million tonnes of sulfur dioxide, gave rise to what has since become known as the "Laki haze" across Europe.
The parish minister and provost of Vestur-Skaftafellssýsla, Jón Steingrímsson (1728–1791), grew famous for the eldmessa ("fire mass") that he delivered on 20 July 1783. The church farm of Kirkjubæjarklaustur was endangered by a branch of the lava flow that halted not far from the farm while the Rev. Jón and his parishioners were worshipping in the church. The spot at which the lava diverted away from the church became known thereafter as Eldmessutangi ("Fire Mass Point").
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 (now the Czech Republic) 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 ships stayed in port, unable to navigate, and the sun was described as "blood coloured".
Inhaling sulfur dioxide gas causes victims to choke as their internal soft tissues swell – the gas reacts with the moisture in the 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 east of England was most affected. 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, Quotes reports from the Newcastle Courant and Cumberland Pacquet newspapers. until the haze dissipated in the autumn. The winter of 1783–1784 was very severe; Quotes reports from the Newcastle Courant and Cumberland Pacquet newspapers. 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. This is considered part of a volcanic winter.
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 failed harvest in 1785 that caused poverty for rural workers, as well as droughts, bad winters and summers. 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.
Benjamin Franklin recorded his observations in America in a 1784 lecture:
According to contemporary records, Hekla did not erupt in 1783; its previous eruption was in 1766. The Laki fissure eruption was east and the Grímsvötn volcano was erupting about northeast. Katla volcano, only southeast, 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 (the same date on which Gilbert White noted the onset of the unusual atmospheric phenomena), in a letter to Joseph Banks, then President of the Royal Society:
Sir John goes on to describe the effect of this "frost" on trees and crops:
target="_blank" rel="nofollow"> A Sulphurous Stench: Illness and Death in Europe Following the Eruption of the Laki Fissure
|
|
