Tuesday, August 27, 2013

Local and Global Impacts of the 1783-84 Laki Eruption in Iceland

Part of the Laki fissure system in Iceland that erupted from June 1783 until February 1784 in one of the largest eruptions in recorded history. Image: Ulrich Latzenhofer / Fotopedia.

Distribution of the 1783-4 Laki haze across the northern hemisphere. Image: Thordarsson and Self (2003)

Saturday marks the 230th anniversary of the famed Laki (or Skaftár Fires) eruption in Iceland — one of the largest volcanic eruptions in recorded history. It wasn’t a enormous explosion like many people associate with giant eruptions, nothing like Tambora or Krakatau. However, it did have a profound impact on people living around the entire Northern Hemisphere for years afterwards, although the direct impact the eruption had on the Earth’s climate is still a widely debated and researched topic. In honor of this anniversary, I thought I’d try to give a brief primer on the eruption and why it is such an important eruption, both in terms of Icelandic volcanism and its global impact.



In 1783, the Laki Volcano in Iceland exploded. Around 10,000 Icelanders were killed—almost one-fifth of the country’s population. Up to 60 percent of livestock was destroyed and entire regions of the country laid to waste—but the volcano’s effects weren’t confined to this one island. For six months the volcano pumped out more sulphur dioxide than has ever been released into the atmosphere in modern history. And that cloud of sulphur would have catastrophic consequences across the Northern Hemisphere.

That summer, Europe was plagued by disaster. A thick fog settled in the West, dense and poisonous. Crops shriveled and died, gigantic hailstones came crashing to Earth, and an intense, suffocating heat sparked apocalyptic thunderstorms. The naturalist Gilbert White described the haze as being “unlike anything known within the memory of man.” According to his account:

“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. At the same 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 . . . the country people began to look with a superstitious awe, at the red, louring aspect of the sun.”

For people across Europe and North America, it seemed like the end times had come. When the fog finally dissipated and winter came, it brought little relief. The ground froze, temperatures plummeted to the lowest in 250 years and 8,000 people froze to death in the UK alone. In New Orleans, the Mississippi was said to have turned to solid ice. When spring came, the thaw triggered deadly flash floods, and the USA became engulfed in howling snowstorms. Back in Europe, the economy ground to a halt while famines in Egypt caused food prices to shoot up—perhaps indirectly causing the 1789 French Revolution.

Today, the Laki Haze is all but forgotten—everywhere except Iceland, where the combined effects are known as “the hardship of the fog.” In an age where minor hurricanes and unseasonal snowfall are routinely described as signs of an impending climate apocalypse, perhaps we should all spare a thought for the 30,000 Europeans who died during that harrowing summer—when it seemed like Mother Nature had finally turned.

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