We come back to the departure of the Vikings from Greenland: they would have fled not because of the cold, but because of a sudden rise in sea level.
Mathilde Fontez, editor-in-chief of the scientific magazine Epsiloonspeaks to us today of the Vikings: we know that they populated Greenland from the 10th to the 15th century, but the reasons for their departure remained mysterious.
franceinfo: Researchers conclude that the Vikings would have fled Greenland because of a rise in sea level?
Mathilde Fontez: Yes, many causes are mentioned to explain this disappearance of the Vikings: social unrest, economic disruption. And especially the arrival of the Little Ice Age (between the beginning of the 14th and the end of the 19th century), which would have changed the climate – it is often said that Greenland was green, before being covered in ice.
So everything is probably somewhat true, but by precisely studying the behavior of Greenland’s glaciers at this time, with simulations, Harvard researchers found the trigger. Yes, it is a rise in sea level: a local rise in water of more than 3 meters which would be responsible for the exodus of the Vikings.
The cooling of PLittle Ice Age did he create this rising water?
Yes, it’s counter-intuitive, we are more used to warming raising sea levels and cooling lowering them. But that’s what the researchers show. Glaciers have grown, especially the South Greenland Glacier, and they have caused land subsidence. The very important layer of ice also influenced, by gravity, the water level, and created this elevation, over 2000 km.
The researchers estimate that the coastline has retreated several hundred meters. Between the years 1000 and 1450, the Viking colonies would therefore have lost 200 km² of land. And that was probably kind of a big straw too much for this society: the floods brought them to a tipping point.
Why had this phenomenon been ignored until then?
Most of the studies on the disappearance of the Vikings were rather based on archaeological data, which leave room for several interpretations. Moreover, some support this rise in sea level: for example, archaeologists have found drowned ruins, and traces of attempts by the Vikings to adapt their agriculture to the loss of their land.
It is above all the model used by the researchers that makes the difference: no one had previously analyzed the evolution of the glaciers and the geophysics of the places, with this level of detail.