Laki: The Eruption That Changed History

In the summer of 1783, the earth in southern Iceland tore open. It wasn’t a single mountain exploding; it was the ground itself unzipping. A fissure 25 kilometers (15.5 miles) long opened up, vomiting fountains of fire 1,400 meters into the air. This was the beginning of the Laki eruption (known in Iceland as the Skaftáreldar or “Fires of the Skaftá”).

For eight months, this tear in the planet poured out lava. But it was not the lava that made Laki one of the most deadly events in human history. It was the gas. The eruption released a toxic cloud of sulfur and fluorine that enveloped the Northern Hemisphere, altering the global climate, causing mass starvation, and helping to trigger the socio-political collapse that led to the French Revolution. Laki is a grim reminder that volcanoes do not just reshape landscapes; they reshape civilizations.

Geologic Anatomy: The Lakagígar Fissure

Laki is not a cone volcano like Fuji or Etna. It is a fissure system.

• The Grímsvötn Connection: Laki is actually part of the larger volcanic system centered on the subglacial Grímsvötn volcano. The tension from the diverging North American and Eurasian tectonic plates tore the crust, allowing basaltic magma to surge to the surface.
• The Craters: Today, the site is known as Lakagígar (The Craters of Laki). It consists of a row of over 135 crater cones stretching across the Highlands.
• Scale: The eruption produced an estimated 14.7 cubic kilometers of lava. To visualize this: it is enough lava to bury the entire island of Manhattan under a layer of rock 250 meters (820 feet) thick. It remains the largest basaltic lava flow witnessed in recorded history.

The Fire Priest and the Miracle

The eruption began on June 8, 1783, Pentecost Sunday.

• Jón Steingrímsson: The most famous figure of this catastrophe is the Reverend Jón Steingrímsson. As the lava flows advanced toward the town of Kirkjubæjarklaustur, swallowing farms and churches, the terrified residents gathered in the wooden church for what they thought would be their last service.
• The Fire Sermon: Reverend Jón delivered his legendary Eldmessan (“Fire Sermon”). With the roar of the volcano drowning out his voice and the heat of the lava scorching the church walls, he prayed for deliverance.
• The Miracle: Miraculously, the lava flow stopped just meters from the church door. It split and flowed around the town. While geologists explain this by the local topography (the flow hit a narrowing in the river gorge that acted as a dam), to the Icelanders, it was divine intervention. Jón’s written accounts remain the most detailed scientific observation of the event.

Móðuharðindin: The Mist Hardships

In Iceland, the aftermath is known as Móðuharðindin (“The Mist Hardships”). It was an apocalypse.

• The Poison: The volcano released 8 million tons of fluorine. This heavy, toxic gas settled on the grass and fields.
• Skeletal Fluorosis: Livestock that grazed on the contaminated grass developed fluorosis. Their bones softened and grew massive, painful outgrowths. Their teeth turned black and fell out. They could not eat or walk.
• The Toll:
  • Livestock: About 80% of the sheep, 50% of the cattle, and 50% of the horses in Iceland died.
  • Humans: Without livestock, the primary food source was gone. Famine swept the island. Coupled with smallpox, it killed approximately 10,000 people—more than 20% of the entire Icelandic population. The Danish King even considered evacuating the remaining survivors to Denmark, leaving Iceland uninhabited.

The Laki Haze: Europe chokes

The disaster did not stop at Iceland’s shores.

• The Aerosol Cloud: The eruption pumped 120 million tons of sulfur dioxide into the upper troposphere and lower stratosphere. This reacted with water vapor to form distinct layers of sulfuric acid aerosols.
• The Dry Fog: A strange, dry, blueish fog settled over Europe. It did not disperse with the wind. The sun appeared blood-red at noon.
• Respiratory Crisis: In Britain, France, and the Netherlands, people began to die. The acid fog burned the lungs. Parish records in England show a massive spike in deaths during the summer of 1783, primarily among outdoor laborers who breathed the “Laki Haze.”
• Benjamin Franklin: In Paris, the American diplomat and scientist Benjamin Franklin was one of the first to connect the “dry fog” to the volcanic activity in Iceland, writing a prescient paper on the subject.

Climate Chaos and the French Revolution

The climatic impact was global and severe, rippling out from Iceland to touch every continent.

• The Cooling: The sulfuric aerosols reflected sunlight back into space, causing a significant drop in global temperatures. This “volcanic winter” lasted for several years.
• The Winter of Hell: The winter of 1783-1784 was one of the coldest on record in North America and Europe. The Mississippi river froze at New Orleans. Ice floes were reported in the Gulf of Mexico. Chesapeake Bay froze over, trapping ships.
• Monsoon Failure: The cooling of the Northern Hemisphere disrupted the thermal contrast that drives the African and Indian Monsoons. This led to severe droughts in the Nile basin and failed harvests in India, causing famine that killed hundreds of thousands, though the connection to Iceland was unknown at the time.
• The Revolution: In France, the peasantry was already suffering under high taxes. The years of famine and high bread prices caused by the Laki climate anomaly pushed the population to the breaking point. The “Great Fear” and the bread riots of 1789 can be partly traced back to the meteorological chaos unleashed by a fissure in Iceland six years earlier. It is a butterfly effect: a volcano erupts in the Arctic, and a King loses his head in Paris.

Logistics: Driving the F206 to Hell

Visiting Laki is an adventure that requires preparation. It is not a day trip for the casual tourist.

• The Vehicle: You absolutely need a 4x4 vehicle with good ground clearance. Small SUVs (like a RAV4) might struggle; a Land Rover or modified Super Jeep is recommended.
• The Road: The F206 (Lakagígar road) is rough, rocky, and unpaved. It takes about 3-4 hours one way from the Ring Road (Route 1) to reach the Laki parking area.
• River Crossings: There are unbridged river crossings. The depth depends on the rain and glacial melt. Rental car insurance in Iceland typically does not cover water damage. If you drown the engine, you pay for the whole car.
• Ranger Station: There is a ranger station at the site with toilets and information. The wardens offer guided walks during the summer. Listen to them; they know the dangers of the terrain.
• Leave No Trace: Driving off-road is strictly illegal in Iceland. The tire tracks can last for decades in the fragile moss. Stay on the marked trail or face massive fines.

The Landscape Today

Visiting Lakagígar today is a journey into an alien world.

• The Moss: The irony of Laki is that the agent of death (the lava) is now the foundation of fragile life. The expansive lava fields (Eldhraun) are blanketed in a thick, spongy layer of grey-green moss (Racomitrium).
• Fragility: This moss is incredibly fragile. It takes decades to grow. Walking on the moss is strictly forbidden, as a single footprint can scar the landscape for a lifetime.
• Accessibility: Laki is located in the Highlands. It is only accessible by 4x4 vehicles (Super Jeeps) during the short summer months (July-August) via the rugged F206 mountain road.
• The View: Hiking up the Laki mountain (the highest peak in the crater row, 818m) offers a staggering view. You can see the line of craters stretching to the horizon like a scar on the earth, a silent testament to the violence of the past.
• Photography: The contrast between the black lava, the neon-green moss, and the blue sky is a photographer’s dream. The best light is often in the late afternoon when the shadows lengthen, emphasizing the dramatic texture of the craters. Bring a wide-angle lens to capture the scale of the fissure, but also a macro lens for the intricate details of the moss.

Science: The Laki Basalt

Scientific study of Laki changed volcanology.

• Flood Basalts: It provided the modern model for understanding flood basalts—massive, high-volume eruptions that have caused mass extinctions in the geological past (like the Siberian Traps).
• Atmospheric Chemistry: It helped scientists model the concept of “volcanic winter,” which was crucial later for understanding the risks of nuclear winter and geoengineering.

Conclusion: A Warning from the Past

Laki is not dead; it is merely sleeping. The system erupted again in 2011 (at Grímsvötn) and is showing signs of unrest. In a modern world dependent on air travel and just-in-time supply chains, a repeat of the 1783 Laki eruption would be a global catastrophe of unimaginable scale. It serves as a beautiful, moss-covered monument to the fragility of our civilization in the face of the planet’s raw power.