Iceland's Laki volcano erupted in 1783, freeing gases that turned into smog. The smog floated across the Jet Stream, changing weather patterns. Many died from gas poisoning in the British Isles. Crop production fell in western Europe. Famine spread. Some even linked the eruption, which helped fuel famine, to the French Revolution. Painters in the 18th century illustrated fiery sunsets in their works.(visit the link for the full news article)
The winter of 1784 was also one of the longest and coldest on record in North America. New England reported a record stretch of below-zero temperatures and New Jersey reported record snow accumulation. The Mississippi River also reportedly froze in New Orleans
"These are Hollywood-sort of scenarios but possible," said Colin Macpherson, a geologist with the University of Durham. "As the melt rises, it's a little like taking a cork out of a champagne bottle."1
Documentary evidence suggests there may have been
significant human illness and morbidity in parishes in rural England in
the late eighteenth century. Demographic data for a number of rural
parishes in different environmental settings point to a singular peak in
burials taking place in 1783. The Laki Fissure eruption of 1783-84 and
the resultant atmospheric loading by gas and sub-PM10 aerosol, in
particular H2SO4 generated massive, but entirely natural air pollution.
In northwest Europe, the air pollution was manifested as a persistent,
foul-smelling dry fog and various forms of acid-damage to crops, trees
and water-bodies and a consistent range of human health problems.
These link the presence of the dry fog with headaches, eye irritation,
decreased lung function and asthma. The concept that intense
anthropogenic air pollution may cause respiratory illness and/or the
death of vulnerable sections of the population is familiar in modern
western societies. There is no reason to suggest that volcanic air
pollution may not have had a similar impact in the past. Mortality
patterns from widely separated English rural parishes suggest that a
crisis did occur during the summer of 1783 û awareness of physical
process and the circumstantial evidence suggests acid volcanic gases
may have been the key agent. Calculation of mortality indices from
available demographic data does suggest that death rates did increase
significantly at this time and mortality in the summer of 1783 is
classified as a ôcrisisö. In raw numbers over 10 000 more people died
at this time than would normally be expected û this is actually a 1000
more people than died in Iceland following the Laki fissure eruption.
USGS
For eight months during the years 1783-1784, lava erupted from dozens of vents along a 27-km-long (17-mile-long) fissure system in the highlands of southern Iceland. Basaltic lava flows—just like the flows we see here in Hawai`i—poured south out of the mountains onto the coastal plains, burying 599 square km ( 231 square miles) in the process. The total volume of lava erupted in eight months is estimated at 15.1 cubic km (3.6 cubic miles). In comparison, Kīlauea's ongoing east rift zone eruption, approaching the end of its 26th year of activity, has produced only about 3.4 cubic km (0.8 cubic miles) of lava.
In addition to these enormous lava flows, eruptive episodes from the Laki fissure started with explosive eruptions that blanketed more than 8,000 square km (3,089 square miles) with volcanic ash and cinders. And if you think the vog here can be bad, Laki pumped out 122 million tons of sulfur dioxide in eight months. Compare this to Kīlauea's 0.85 million tons from February to September, 2008—less than one percent of Laki's output over the same length of time. Half of the livestock in Iceland died after eating grass contaminated with fluorine from the gas plume, and 20 percent of Iceland's population starved during the famine that followed. The sulfur dioxide released led to crop failures throughout Europe and may have led to, or exacerbated, other famines in the northern hemisphere that occurred at about the same time.
... I would give you a lot more stars (not flags) if I could 
The Icelandic volcano Eyjafjallajökull has been very restless recently. The current seismicity and apparent inflation may be precursory to an eruption, or it may not.
It seems, however, that there is a connection between these two closely-spaced volcanoes. Eyjafjallajökull’s most recent eruption, December 1821 to January 1823, was followed by an eruption of Katla in June and July 1823. More recently an intrusion at Eyjafjallajökull in 1999 appears to have been followed by a small subglacial eruption in the Katla caldera.
It’s intriguing that recent earthquake activity around Katla and Eyjafjallajökull has clustered in three areas: (1) shallow quakes around and within the Eyjafjallajökull caldera, (2) shallow quakes largely confined to the eastern part of Katla caldera, and (3) quakes with a deeper focus in the Godabunga area between the first two clusters. One possible interpretation of this pattern is that a cryptodome – an underground lava dome – is active beneath this area. The presence of viscous rhyolitic lava beneath Katla and Eyjafjallajökull makes for potentially explosive eruptive activity, if an eruption occurs.
PDF Cited Abstract
I would also like to point out that if we by an active volcano even mean a volcano that is likely to erupt some time again most of the Icelandic fissure volcanoes such as Laki can be left out as active because seldom during the whole postglacial time it has happened that a fissure has erupted more than once. Hekla is the main exception from this rule in Iceland.
Be it as it may with the number of active volcanoes in Iceland.
What we can tell with certainty is, that during the last two centuries
or so we have had an eruption on average every fifth to sixth year.
And it is also an established fact that many eruptions in Iceland in
Historical time have wrought great havoc and some of them resulted
in most disastrous catastrophes such as the Helda initial eruption in
1104, the initial eruption of OrsefajSkull in 18622 the Kafla eruption
Geology.com
Researchers in a NASA/NSF/NOAA funded study have identified connections between high latitude volcanic eruptions and periods of low water flow in African rivers. Using computer models they linked Iceland's Laki Volcanic Event (a series of about ten eruptions that occurred between June 1783 and February 1784) to the lowest water levels in the Nile River in a historical record dating back to 622 AD.
Using computer models developed by NASA they found that the Laki Volcanic Event altered surface temperature patterns that produced extremely low levels of rainfall across much of Africa. The initial atmospheric response to the eruption was a decline in global temperatures. This temperature decline produced a reduced temperature difference between land and ocean. Without that temperature contrast, onshore winds weakened and the delivery of moisture and rainfall from the ocean was severely reduced.
Originally posted by thoughtsfull
reply to post by segurelha
Tis rather disconcerting that this thing has come along right now... I appears almost as if the deck is being stacked against mankind.
Originally posted by DaddyBare
Originally posted by thoughtsfull
reply to post by segurelha
Tis rather disconcerting that this thing has come along right now... I appears almost as if the deck is being stacked against mankind.
You said it brother!
Funny how this little news blurb might just turn out to be the most important post to ever grace ATS.... or the entire world for that matter
RSOE AlertMap
An earthquake swarm began under Eyjafjoll volcano in January 2010. There was a 40 mm inflation of the volcano. At the beginning of March 2010 over 3000 earthquakes were measured in a 24 hour period, with a maximum at magnitude 3.1. The last eruptions at Eyjafjoll volcano were in 1821-23. The subglacial Esjufjöll volcano at the SE part of the Vatnajökull icecap, north of Öraefajökull volcano, consists of the Snaehetta central volcano and a large caldera. Most of the volcano, including the 40 sq km caldera, is covered by the icecap, but parts of the SE flank are exposed in NW-SE-trending ridges. Most of the exposed rocks are mildly alkaline basalts, but small amounts of rhyolitic rocks are also present. A large jökulhlaup that came down the Jokulsa a Breidamerkursandi along the coast SE of Vatnajökull in the beginning of September 1927 was accompanied by a sulfur stench, and on one occasion, ash fall on the Breidamerkurjökull considered to have possibly originated from Esjufjöll. Although Holocene eruptions have not been confirmed from Esjufjöll, earthquake swarms that could indicate magma movements were detected in October, 2002.
