There are no written records that explain why the Vikings left or became extinct. But a new simulation of the coast of Greenland reveals that when the ice sheet that covers most of the island began to expand around that time, sea levels rose dramatically. the researchers report on 15 December at the fall meeting of the American Geophysical Union in New Orleans.
These shifting coasts would have inundated grazing areas and farmland and could have contributed to the end of the Nordic way of life in Greenland, says Marisa Borreggine, a geophysicist at Harvard University.
Greenland was first colonized by the Vikings in 985 by a group of settlers on 14 ships led by Erik the Red, banished from neighboring Iceland for manslaughter. Erik and his followers settled in southern Greenland, where they and their descendants hunted seals, grazed cattle, built churches, and traded walrus ivory with European continentals.
The settlers arrived during the so-called medieval warm period, when conditions in Europe and Greenland were tempered for a handful of centuries. But by 1350, the climate had begun to deteriorate with the onset of the Little Ice Age, a period of regional cooling that lasted well into the 19th century.
Researchers have long speculated that a rapidly changing climate could have dealt a severe blow to Greenland’s Norse society. The island has likely gotten much colder over the past 100 years of Norse occupation, says paleoclimatologist Boyang Zhao of Brown University in Providence, RI, who was not involved in the new research. Lower temperatures could have made farming and livestock farming more difficult, he says.
For the Vikings only escape remained
These lower temperatures would have had another impact on Greenland: the constant expansion of the island’s ice sheet, Borreggine and colleagues say. Although sea level rise usually goes hand in hand with it ice melting, the oceans do not rise and fall uniformly in every place, says Borreggine. Around Greenland, sea level tends to rise as the ice sheet grows.
This is for two main reasons: First, the ice is heavy. The sheer weight of the ice sheet pushes down the earth it rests on, meaning that as the ice sheet grows, more land is submerged. The second is gravity. Being huge, the ice sheets exert a certain gravitational pull on nearby water.
This causes the seawater around Greenland to tilt upward towards the ice, which means that the water closest to the coast is higher than the water in the open ocean. As the ice sheet grows, this attraction becomes even stronger and the sea level near the coast rises further.
By simulating the impact of the weight of the ice and its tug on the waters of Greenland, Borreggine and their colleagues found that sea levels rose enough to flood the coast by hundreds of meters in some areas. Between the arrival of the Vikings and their departure, there was “A rather intense coastal flood, such that some pieces of land that were connected to each other were no longer connected”, they say.
Today, some Viking sites are being flooded due to the general global sea level rise due to climate change, which is only marginally offset around Greenland by the melting of the ice sheet. Something similar may have happened in the 14th and 15th centuries, destroying the land the Norwegians relied on for agriculture and grazing, Borreggine says.
“Previous theories as to why the Vikings left really focused on the idea that they all died because it was so cold and they were too stupid to fit in,” says Borreggine. But they say archaeological excavations have revealed a much more nuanced story, showing that the Norwegians of Greenland have changed their way of life by relying more and more on seafood in the last century of their occupation.
But learning to adapt may have been too difficult in the face of an increasingly rugged landscape. The idea that sea-level rise may have been one of these challenges has merits, says Zhao, noting that the reasons why the Vikings disappeared from Greenland have vanished.
With climate change, for example, these people may also have found themselves increasingly cut off from trade routes as the season of thick sea ice extended. And by the mid-14th century, the Black Death was spreading across Europe, cutting down on the largest Viking market. for walrus ivory.
“The Norwegians have come and gone”, says Zhao. “But there are still a lot of unresolved questions,” including exactly why they left, he says.
The last written record of this company is a letter describing a marriage in 1408. A few years later, that couple moved to Iceland and started farming. The reason the couple chose to leave is lost in history, but as new research suggests, sea level rise it may have been part of the equation.
#Vikings #fled #Greenland #escape #rising #seas