In Iceland, in 939 CE, the sky suddenly went dark and the Earth began to glow a hideous orange.
The locals – so recent to the land that they still told fresh tales of their parents and grandparents arriving from Norway fewer than 70 years earlier – had no idea why or how their country roared and flared and then, in weeks, grew cold and hazy.
Within a couple of decades, however, the poets and philosophers among them had worked it out: the old Norse gods were dead and a new singular deity had arisen.
That’s the theory put forward by a team of researchers led by geographer Clive Oppenheimer from the University of Cambridge in the UK, which for the first time pinpoints the date of a massive volcanic eruption and the advent of one of Iceland’s most influential epic poems, or sagas.
In a paper published in the journal Climatic Change, Oppenheimer and colleagues report using ice core data from Greenland to pinpoint the date of the eruption of Iceland’s Eldgjá volcano.
The eruption and its widespread after-effects are mentioned in several early literature sources from Ireland, Germany, Egypt and even China, but such is the nature of early Medieval documents – often surviving in copied versions, or fragments – that precise dating is impossible. By assessing sulfur concentrations in core samples, the scientists pinpointed the initial eruption to the northern spring of 939 CE and established that it continued, perhaps sporadically, until the autumn of 940.
Severe winters caused by the massive clouds of particles thrown up by the violent eruption went on for many years, causing ongoing suffering and hardship.
“Human suffering in the wake of Eldgjá was widespread,” says co-author Tim Newfield. “From northern Europe to northern China, people experienced long, hard winters and severe spring-summer drought.
“Locust infestations and livestock mortalities occurred. Famine did not set in everywhere, but in the early 940s we read of starvation and vast mortality in parts of Germany, Iraq and China.”
Nowhere, of course, was more terribly affected than Iceland itself. The colony was young, and no doubt hit by famine and the loss of land only recently occupied. Yet no unambiguous direct references, if there ever were any, have survived in the local literature.
When reportage is absent, however, allegory fills the void. Oppenheimer and his team point to an influential and apocalyptic Icelandic epic poem, called Voluspá – The Prophecy of the Seeress – which has been dated to at least as far back as 961CE.
The saga tells the story of a prophetess who was raised by the great god Odin from the dead. The prophetess tells of the death of the pagan pantheon and its replacement by a new solo deity.
The language of the saga, Oppenheimer and colleagues argue, suggests that the writer (or writers) were strongly influenced by earlier eye-witness accounts of the volcanic eruption.