Human Saga

Eldgjá Eruption in Iceland

939-940 CE·Environment & climate·Europe (Iceland)·
939-940 CEDate
Environment & climateCategory
23Empires active
Date
939-940 CE
Category
Environment & climate
Region
Europe (Iceland)
Era
Post-Classical / Medieval
Significance

The Eldgjá eruption, which began in the spring of 939 CE and continued at least episodically until the autumn of 940 CE, was the largest effusive (lava-producing) volcanic eruption on Earth in the last few millennia.

Issuing from a roughly 75-kilometre volcanic fissure system in southern Iceland, it discharged on the order of 18 to 20 cubic kilometres of basaltic lava and released approximately 200 million tonnes of sulphur dioxide into the atmosphere. The resulting sulphate veil drove pronounced Northern Hemisphere summer cooling of around 0.7 to 1.5 °C in 940 CE, and contemporary chronicles from Ireland, Germany, Italy, and elsewhere recorded a blood-red sun, dimmed skies, and a persistent haze. Severe winters and failed harvests between 939 and 942 CE triggered famine and hardship across Europe, the Middle East, and China. Within Iceland the eruption buried and depopulated wide tracts of the recently settled south, and scholars have argued that its apocalyptic imagery, preserved in the Old Norse poem Vǫluspá, was later invoked to encourage the island's conversion to Christianity around 999/1000 CE.

See the world map in 939-940 CE →More environment & climateThe Post-Classical / Medieval era

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Empires active in 939-940 CE

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A New Green History of the World

Clive Ponting

The classic accessible account of how environment and climate have shaped human history.

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