The Eldgjá eruption and the Christianisation of Iceland

A series of Earth-shattering volcanic eruptions in Iceland during the Middle Ages may have spurred the people living there to turn away from their pagan gods and convert to Christianity, a new study finds.

The discovery came about thanks to precise dating of the volcanic eruptions, which spewed lava about two generations before the Icelandic people changed religions.

codex_regius_of_eddaic_poems
Codex Regius

But why would volcanic eruptions turn people toward monotheism? The answer has to do with the “Vǫluspá,” a prominent medieval poem that predicted a fiery eruption would help lead to the downfall of the pagan gods, the researchers said.

Historians have long known that the Vikings and Celts settled Iceland in about A.D. 874, but they were less certain about the date of the Eldgjá lava flood, the largest eruption to hit Iceland in the past few millennia. Knowing this date is crucial, because it can tell scientists whether the eruption — a colossal event that unleashed about 4.8 cubic miles (20 cubic kilometers) of lava onto Greenland — impacted the settlement there, the researchers said.

To investigate, the researchers examined ice core records. Their results showed that the eruption took place less than 100 years after people settled the island. The volcano began gushing lava in the spring of A.D. 939 and lasted, at least episodically, until the autumn of 940, the researchers said.

10584_2018_2171_Fig1_HTML
a) Locations of Eldgjá, the NEEM drill site and medieval documentary evidence referenced in the text covering 939–942 CE. b) Section of the 75-km-long Eldgjá eruption fissure at Ófærufoss. c) The Codex Regius; finger points to beginning of stanza 57 of Vǫluspá

“This places the eruption squarely within the experience of the first two or three generations of Iceland’s settlers,” study lead researcher Clive Oppenheimer, a professor of volcanology at the University of Cambridge, in England, said in a statement. “Some of the first wave of migrants to Iceland, brought over as children, may well have witnessed the eruption.”

The finding matches medieval chronicles from Ireland, Germany and Italy that noted the spread of a haze in 939. Moreover, the tree-ring data revealed that in A.D. 940, the Northern Hemisphere had one of its coldest summers in the previous 1,500 years — a cold shift consistent with the release of large amounts of volcanic sulfur into the atmosphere, the researchers said.

“In 940, summer cooling was most pronounced in Central Europe, Scandinavia, the Canadian Rockies, Alaska and Central Asia, with summer average temperatures 2 degrees Celsius [3.6 degrees Fahrenheit] lower,” co-researcher Markus Stoffel, a professor in the Department of Earth Sciences at the University of Geneva in Switzerland, said in the statement.

Suffering followed, with hard winters and drought in the spring and summer. Locusts invaded, and livestock died. “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,” said study co-researcher Tim Newfield, an environmental historian at Georgetown University, in Washington, D.C.

However, no texts from that period survive from Iceland, the volcano’s homeland.

A mere two generations after the Eldgjá eruption, in about A.D. 1000, the people of Iceland formally converted to Christianity. And it likely had to do with the “Vǫluspá,” the researchers said.

The “Vǫluspá” was written after the eruptions, in about A.D. 961. It describes how an eruption and meteorological events would mark the end of the pagan gods, who would be replaced by one, singular god, the researchers said.

Part of the poem explains how “the sun starts to turn black, land sinks into sea; the bright stars scatter from the sky … flame flies high against heaven itself,” according to a translation.

Considering Eldgjá’s eruptions date to before the poem was written, Icelanders who experienced the fiery spectacle likely looked back at the events and wrote the poem, “with the purpose of stimulating Iceland’s Christianization over the latter half of the 10th century,” the researchers wrote in the study, published online in the journal Climate Change.

SOURCE.

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What wiped out almost a third of Londoners in 1258?

From The Guardian:

When archaeologists discovered thousands of medieval skeletons in a mass burial pit in east London in the 1990s, they assumed they were 14th-century victims of the Black Death or the Great Famine of 1315-17. Now they have been astonished by a more explosive explanation – a cataclysmic volcano that had erupted a century earlier, thousands of miles away in the tropics, and wrought havoc on medieval Britons.

Spitalfields Market in east London where 10,500 medieval skeletons were found.

Scientific evidence – including radiocarbon dating of the bones and geological data from across the globe – shows for the first time that mass fatalities in the 13th century were caused by one of the largest volcanic eruptions of the past 10,000 years.

Such was the size of the eruption that its sulphurous gases would have released a stratospheric aerosol veil or dry fog that blocked out sunlight, altered atmospheric circulation patterns and cooled the Earth’s surface. It caused crops to wither, bringing famine, pestilence and death.

The Icelandic volcano of 2010, which spewed out ash which disrupted flights for a few days, was miniscule in comparison.

Mass deaths required capacious burial pits, as recorded in contemporary accounts. In 1258, a monk reported: “The north wind prevailed for several months… scarcely a small rare flower or shooting germ appeared, whence the hope of harvest was uncertain… Innumerable multitudes of poor people died, and their bodies were found lying all about swollen from want… Nor did those who had homes dare to harbour the sick and dying, for fear of infection… The pestilence was immense – insufferable; it attacked the poor particularly. In London alone 15,000 of the poor perished; in England and elsewhere thousands died.”

There does not seem to have been any explanation at the time; it was probably assumed to be a punishment from God. London’s population at the time was around 50,000, so the loss of 15,000 would have radically changed the city.

Surprisingly, perhaps, the volcano’s exact location has yet to be established. Mexico, Ecuador and Indonesia are the most likely areas, according to volcanologists, who found evidence in ice cores from the northern hemisphere and Antarctic and within a thick layer of ash from Lake Malawi sediments. The ice core sulphate concentration shows that it was up to eight times higher than Indonesia’s Krakatoa eruption of 1883, one of the most catastrophic in history.

Some 10,500 medieval skeletons were found at Spitalfields market, the site of the Augustinian priory and hospital of St Mary Spital, and the remains suggest there may have been as many as 18,000. The excavation between 1991 and 2007 by the Museum of London Archaeology (Mola) was the largest ever archaeological investigation in the capital. It was a member of that team, osteologist Don Walker, who discovered the link with a volcano. The findings will be revealed in Mola’s report, to be published on Monday.

“That was a eureka moment,” he told the Observer. “These people living in medieval London would have had no idea that this global event – one of the largest volcanic eruptions of the Holocene, which is the last 10,000 years, and certainly the largest of the last millennium – was causing the problems.”

He now believes that mass burials in medieval pits across Britain and Europe might also have been caused by the same disaster.

When the skeletons were found, he said: “People immediately thought Black Death, or battle graves, but there wasn’t enough evidence of injuries.” Radiocarbon dating revealed dates around 1250. “So we thought ‘what could it be’?”

Delving into documentary evidence he found references in 1257-58 to “heavy rains” and “a failure of the crops; …a famine ensued… many thousand persons perished”. Specific diseases of malnutrition – scurvy and rickets – were also found among some skeletons, although malnutrition would not have been the sole cause of death during famine. Many would have suffered hunger-induced diseases, such as dysentery, and diseases which are more a product of social disruption caused by famine, such as typhoid fever.

In exploring the cause of such devastation, he discovered that volcanologists had been trying to locate the site of this massive volcano. He said: “What is new is linking the cause of the deaths of so many thousands to this volcano. No-one has linked it to archaeological evidence – and specifically to these mass burial pits. Documentary evidence is not necessarily reliable, whereas now we’ve got physical evidence.”

Mass burial pit in east London – next to Spitalfields Market

Volcanologist Bill McGuire, author of Waking the Giant, on how climate triggers earthquakes, tsunamis and volcanoes, said: “Volcanoes have a very long reach because they can impact climate…They don’t just affect people nearby.”
He cited an Icelandic eruption in 1783 which produced a sulphurous cloud that hung over Europe for nearly a year, affecting air quality and causing thousands of deaths.

The 13th-century eruption was far bigger, he said. “This was the biggest eruption in historic times. It may have brought the temperatures down by 4°c, a huge amount. Because it was somewhere in the tropics it meant that the winds of both hemispheres were able to carry these gases right across the planet. If you have a volcanic eruption at high latitudes, then the gases will stay in the northern hemisphere. But if you have an equatorial or tropical eruption that’s big enough, then the sulphur gases can spread into both hemispheres and really encircle the whole planet in a sulphurous veil.”

McGuire is Professor of Geophysical and Climate Hazards at University College London. Asked whether another such volcanic eruption is due, he said: “It’s been pretty quiet for a while. I’m looking forward to something big.” Only a volcanologist would take that view.