Laki

Iceland sits where two pieces of the Earth's outer shell pull apart.

Hot rock rises there and makes volcanoes.

Iceland sits on the Mid-Atlantic Ridge, where the Eurasian and North American plates move apart and new crust forms. It grows by about two centimeters a year, one centimeter to the east and one to the west. It also sits on a hot spot, where hot rock rises from deep inside the Earth.

Laki belongs to the Grímsvötn volcanic system, which Kleemann calls Iceland's most productive. The mountain Laki itself, in the middle of the fissure, did not erupt in 1783.

Iceland formed over the past 24 million years at a diverging plate boundary on the Mid-Atlantic Ridge, perched on both the Eurasian and North American plates, and above a mantle plume (hot spot). It grows about 2 cm a year.

The Laki Fissure lies in the Grímsvötn system, Iceland's most productive volcanic system, fed by a central volcano beneath the Vatnajökull ice sheet and averaging one eruption every 2-7 years. Mount Laki, a mountain of volcanic origin in the middle of the fissure, did not itself erupt in 1783.

In 1783, lava poured out of the crack for eight months.

The lava flowed down river beds toward the coast.

The eruption began on 8 June 1783 and lasted until 7 February 1784. It came in ten episodes, each starting with strong earthquakes and explosions that opened a new part of the fissure.

It produced 14.7 cubic kilometers of lava, which flowed downhill along the beds of glacial rivers, mainly the Skaftá, and covered 599 square kilometers. People in the area were able to leave before the lava arrived, and its gas drifted to Europe as a dry, sulfur-smelling fog.

The 1783-1784 eruption (Icelandic name Skaftáreldar) comprised ten eruptive episodes, each beginning with strong earthquakes and explosive activity that opened a new fissure segment. It produced 14.7 km³ of lava covering 599 km², which traveled from about 600 m down to the coastal plains mainly via the beds of two glacial rivers, including the Skaftá.

Icelanders evacuated before the lava arrived; the gas, carried by the jet stream, appeared in Europe as a sulfuric-smelling dry fog. Such flood-lava events recur every 300-1,000 years (Kleemann).

Today, green moss grows on the old lava.

If you step on it, it turns brown and dies.

Today a very delicate moss grows on the Laki lava field, painting the hills light green. Because of the high altitude and northern latitude, it is very sensitive and takes decades to grow.

If someone steps on it, the moss turns brown and dies. Warning signs teach visitors about it, and volunteers have built wooden paths for people to walk on.

On the Skaftáreldahraun, the Laki lava field, a very delicate moss paints the hills a lush light green. At this altitude and latitude it is very sensitive and takes decades to grow; stepped on, it turns brown and dies.

Warning signs educate visitors, and volunteer conservationists have built wooden paths. Kleemann notes that some tourists leave litter behind or leave the designated pathways.

Stay on the paths so the moss can live.

Near volcanoes, always listen to the local officials.

Laki is part of Vatnajökull National Park, set up in 2008. Reaching it from the village of Kirkjubæjarklaustur takes about eight hours there and back on a four-wheel-drive bus, over bumpy dirt roads and through rivers. Stay on the wooden paths and take your litter home.

Iceland watches its volcanoes closely. The US Centers for Disease Control and Prevention (CDC) says to follow local officials' advice, and to keep breathing protection and goggles in an emergency kit, because volcanic ash can harm your lungs.

Vatnajökull National Park, established in 2008, now incorporates the Laki Fissure; the round trip from Kirkjubæjarklaustur, 50 km away, takes about eight hours by four-wheel-drive bus on F-roads, fording several rivers (Kleemann).

Iceland monitors its volcanoes and warns people to evacuate when an eruption is imminent. The CDC advises following local officials on preparation and evacuation, with respiratory protection and goggles in an emergency kit, since ash can harm the respiratory tract.