Laki

F2

One of the Laki crater

Western Laki crater row

The Lakagígarbdep2

The Laki craters ( Isl Lakagígar ) are in the south of Iceland near the eruptive fissure Eldgjá. The craters range is attributed to the volcanic system of Grímsvötn. This is due, among other things, that the 1783 Grímsvötn erupted simultaneously with the Lakikratern ( From August 1783, with interruptions until the year 1785 ).

• 3.3.1 1783
• 3.3.2 1784

• 3.4.1 Contemporary illustration and discussion

• 6.1 photos
• 6.2 Consequences of the Laki eruptions
• 6.3 Scientific Articles
• 6.4 Other

Description of the Environment

Between the glacier fields of Mýrdalsjökull and Vatnajökull extends to 50 km in length, the so-called " strip of land " with numerous oriented from southwest to northeast columns.

The area, which includes the Eldgjá belongs, is known for some of the most violent volcanic eruptions in Iceland. Therefore, these districts were called in the vernacular also eldhéröð - dt the fire districts.

The crater row

It is about 130 to 140 cinder cones, welding cinder cones and two tuff cones that extend over about 25 km southwest-northeast direction and the orientation parallel to the grave breach of the eastern volcanic zone in Iceland about.

The crater row was during a series of eruptions in the 18th century, which lasted from 1783 to 1784. Further eruptions from the crater row it has not been given.

The outbreak of 1783-1784: Móðuharðindin

The concept Móðuharðindin

Móðuharðindin (Icelandic for example: Not with the fog ) was a natural disaster that occurred in the years 1783 to 1784 in Iceland. This was caused by the eruption of the volcano Lakagígar who had even affect the global climate. Isl Moda in German means moisture, mist, fog ..

The eruption of the volcano column of Lakagígar (German Lakikrater ), the number of earthquakes were preceded, began on June 8, 1783 and lasted until February 7, 1784th He is regarded as one of the largest volcanic eruptions documented in historical times. The eruption devastated a significant part of southern Iceland and had an impact primarily on Iceland, but also to the entire global climate. Because of the volcanic winter caused thereby led to crop failures and mass extinctions worldwide.

Impact in Iceland

Effusive eruption phases

At the outbreak of 1783/84 a total of about 14.7 km ³ basaltic lava was ejected from a total of about 130 craters, which covered an area of 600 km ². This is the second largest in historical time in Iceland Lavamenge ejected after the Eldgjá. In addition, explosive eruptions at 0.9 km ³ tephra were ejected in addition, what the eruption at VEI 4 rank.

The effusive phase began on the first breakout, on Pentecost Sunday, June 8, 1783, with about 1000 m high lava pillars. The river Skaftá, usually s flow up to 100 m³ / water through the, dried on June 11 due to evaporation completely out. The following day, flowed under a lot of noise lava down the river basins in an amount equivalent to the normal volume of flow of the river. This lava flow did not break down during the next 45 days. When he finally came to a stop, he had a length of 27 km, filled the 100 m deep gorge of the river up to the top and 17 farms and their land covers.

Another very extensive lava flow began in early August to flow and followed the valley of the river Hverfisfljót. The lava flows are called YTRA - Eldhraun and Eystra - Eldhraun.

The fire sermons

Fame of the pastor Jón Steingrímsson from Kirkjubæjarklaustur because of its so-called " fire sermons ." While the congregation was gathered in the church, stopped the lava flow just before the church. The pastor was in 1788 along with detailed reports out about the disaster under the title Eldrit directed against the lava flow " fire sermons " ( eldmessa ). They serve the science, even volcanology, as an important source.

A chapel in Kirkjubæjarklaustur reminded of him.

Gas and ash clouds

By the ejected ash clouds it came to the darkening of the atmosphere and to a marked drop in temperature in Iceland and much of the world. The summers of 1783 to 1785 were unusually short. The country was under the aerosolized veil of a toxic volcanic gases (especially sulfur dioxide) and fluoride - containing particles enriched vapor cloud. From the Icelandic term was coined: " Nebelnot ".

The immense amount of 120 million tons emitted sulfur dioxide reacted with the water droplets of clouds to sulfurous acid and sulfuric acid.

Degassing of fluorine in Iceland

When the eruptions ceased in February 1784, the Laki crater had cast 8 million tons of fluorine; this highly toxic gas was raining mixed with ashes on the ground. It came as a result to the death of vegetation in certain parts of Iceland and over several years in severe crop failures. A large part of the Icelandic livestock of sheep (80 %), cows and horses (50%) perished or had to be slaughtered. A famine was the result, the teeth of the people fell out. About a quarter of the Icelandic population by then about 50 000 died by the beginning of 1785 the consequences of the natural disaster.

Global impacts

1783

In Western Europe, the outbreak had also made. The 120 million tons of sulfur dioxide, which had been thrown into the atmosphere had produced in conjunction with water particles twice the amount of toxic fumes which now migrated with the jet stream to the east and moved circularly over Northern Europe and particularly France and the British Isles. The sulphurous mist was interpreted as the amount of smoke or "dry fog " and was on June 10, over mountains, on the 16th of June, Prague, on 17 June, Berlin, June 18, via Paris, on June 20 via Le Havre and on June 22 across the UK. The sulfuric acid -loaded lungs and resulted in farm workers to a higher death rate (Region Chartres and the UK). Ships sailing from North America to Europe, almost collided with others because of the fog over the Atlantic visibility significantly restricted. Malta was covered on June 20 of such a dense fog that the sun was no longer visible. In England and Finland, there was ash rain. From all over Europe there are numerous reports that mention an unusually foggy climate. As of September 1783, there were heavy rains and storms.

1784

This was followed by a very cold winter of 1783 / 84th In the UK, around 8,000 people died more than in a normal winter. To the east of the United States of America, the average winter temperatures were 4.8 degrees Celsius below the 225 - year mean. The entire northern hemisphere cooled by an average of 1.5 degrees Celsius. The natural scientist Benjamin Franklin said in 1784 the assumption that " a constant fog over all Europe and large parts of North America have placed ". In the spring of 1784 there was heavy flooding caused by melting water.

These eruptions are therefore among the most serious consequences of the past 2,000 years.

Scientific debate on the eruption of Laki

Contemporary illustration and discussion

The outbreaks are a total of unusually well documented. Particularly revealing are the reports of the above- mentioned priest Jón Steingrímsson, " Eldrit " ("A complete description of the SIDA Fires ", 1788).

About the origin of the phenomenon by a broad discussion developed. Many scientists brought it with the earthquake in southern Italy in context, which had been triggered by fermentation or by electrical fire inside the earth. This is the event in the context of the then current debate regarding the origin of the rocks among scientists and interested laymen of the Enlightenment, which split off in different directions, depending on whether they were among the Neptunists, such as Goethe, or the Plutonists, also Vulcanists mentioned.