Exactly a thousand years ago, in 1021, Vikings apparently lived in North America. This is based on a detailed analysis of wooden remains that an international group of researchers is now presenting in the current issue of the journal Nature. The finds are the oldest dated evidence that people came to America from Europe. When determining the age of the pieces of wood, the researchers working with Michael Dee from the University of Groningen rely on traces of a violent solar storm that had occurred a few years earlier.
It has been known for some time that Columbus was not the first European to reach the American continent.
Last but not least, the Sagas, Old Norse stories from the Middle Ages, describe in detail how the Vikings had sailed across the Atlantic with their longships hundreds of years earlier.
But these stories, initially passed down orally, have long been dismissed as myths and fairy tales - also because they contain many contradicting and fantastic elements.
Traces of metal blades
It was not until the discovery of the archaeological site of L'Anse aux Meadows in 1961 on the northern tip of Newfoundland that the Icelandic legends became historical sources.
The exact age of the settlement could not yet be determined, as well as the exact time of the arrival of the Vikings on the American continent.
Three inconspicuous pieces of wood from different trees that were found in L'Anse aux Meadows have now been dated more precisely by the researchers.
The scientists are certain that the wooden artefacts can be assigned to the northern European seafarers - not only because of their place of discovery, but also because they clearly showed signs of processing from metal blades - a material that was not made by the local population at the time.
In answering the question of when the pieces of wood in question were processed, the scientists were helped by radiocarbon dating, which was carried out both at the University of Groningen and at the Curt Engelhorn Center in Mannheim for archaeometry.
And a cosmic event, from the year 992 AD. At that time a massive solar storm occurred, which produced a clear radio carbon signal in the tree rings in the following years.
A new brand for transatlantic contacts
“The clear increase in radiocarbon production between 992 and 993 AD was noted in tree ring archives around the world,” explains research director Dee.
That signal was shown in each of the three wooden objects examined 29 growth rings in front of the bark edge.
"The fact that we found the signal of the solar storm there allows us to conclude that the cutting activity took place in 1021 AD," says Margot Kuitems of the University of Groningen.
The analysis thus sets a new marker for the arrival of Europeans on the American continent, according to the study's authors.
In addition, the potential value of cosmic radiation events - such as the strong solar storm here - shows itself as reference points for the future dating of artifacts and environmental events.
It remains unclear how many expeditions the Vikings made to America and how long they stayed on the continent. Nor is it known so far about the influence of the Viking residences on the natives and on the environment. The Icelandic sagas suggest that the Vikings entered into a cultural exchange with the indigenous peoples of North America, the scientists write. "If these encounters did actually take place, they could have had unintended consequences, such as the transmission of pathogens, the introduction of alien animal and plant species, or even the exchange of human genetic information."
However, recent data from the North Greenland population showed no evidence of the latter.
The authors conclude: “How the year 1021 AD relates to the transatlantic activities of the Vikings as a whole is the subject of future research.
Nonetheless, our results provide a chronological anchor for further investigation into the consequences of their westernmost expansion. "