Vikings abandoned Greenland centuries ago in the face of rising sea levels, new study suggests
Viking settlers occupied parts of Greenland from approximately 985 to 1450, farming and building communities before mysteriously disappearing.Why they left has been a mystery, but a new piece of paper suggests that a surprising factor may be at play: rising sea levels.
“The narrative has shifted from the idea that the Vikings simply failed to adapt to their environment to an argument that they faced a myriad of challenges,” said Marisa J. Borreggine, a Harvard graduate student in the study, just published in the journal Proceedings of the National Academy of Sciences of the United States of America.
The departure of the Vikings coincided with the beginning of the Little Ice Age, when temperatures in many parts of the world dropped dramatically over the course of centuries and the mass of ice sheets increased. While it seemed likely that increased cooling and freezing would lower sea levels, it had the opposite effect in Greenland.
Rising sea levels off the coast of Greenland may have driven Viking settlers away. Today, sea levels are actually falling as the Greenland ice sheet melts. (Margie Turrin/Lamont-Doherty Earth Observatory)
During the Little Ice Age, as the Greenland ice sheet grew, this led to a phenomenon known as Glacier Balance Adjustment, in which the enormous weight of the newly added ice pushes down on the land below. At the same time, the mass of all this new ice increases Greenland’s gravitational pull on the surrounding waters of the North Atlantic. Both factors contribute to coastal sea level rise.
Borreggine’s group looked at Viking eastern settlements from about 1000 to 1450, analyzing the impact on known Viking settlements. During this period, the researchers found that the settlers experienced up to 3.3 meters of sea-level rise throughout their occupation—two to six times the rate of sea-level rise caused by modern humans elsewhere. Noting the partially submerged ruins of Viking storehouses and other sites, the group found that 75 percent of known Viking sites lie within 1,000 meters of flood zones.
“Not only is the ground being pushed down, but the sea is also rising,” Borreggine said. “It’s a double whammy.”
“We focus on [were] Previously unaccounted for environmental changes have been linked to the development of glaciers near Viking settlements,” said study co-authors Evelyn PowellPostdoctoral Research Fellow, Columbia University Lamont-Doherty Earth Observatory“Overall, this study is an inspiring example of the interdisciplinary work that exists at the intersection of geophysical modelling, climate science, and the study of the human condition.”
This 1876 sketch shows a partially submerged Viking site built in the 14th century in the eastern Greenland settlement of Igalikö.
The effects of rising sea levels were also reflected in the changing eating habits of the Vikings. As sea levels rise, they switch from agricultural products to more ocean-based foods, perhaps because their fields are flooded or permanently submerged by rising salt water.
The new study adds to a long-running debate about what prompted Viking migration to Greenland, and their subsequent exodus.this includes A 2015 study Researcher Nicolás Young, from Lamont-Doherty, disputes the prevailing claim that the initial settlement was spurred by an unusually warm period preceding the Little Ice Age known as the Medieval Warm Period. In this region, the Medieval Warm Period actually wasn’t that warm, Young claims.
Today, sea levels are actually falling as the Greenland ice sheet melts in a rapidly warming climate. according to ongoing research By another group at Lamont-Doherty, this happens fairly quickly, adding an inch a year. This presented new challenges for residents: modern coastal settlements without access depend on the often already shallow inlets, straits and shorelines for travel and fishing. That means some communities could be in trouble.
Borreggine notes similarities and one major difference between the Viking Age and modern times. “The Vikings really had no choice,” Borreggine said. “They can’t stop the Little Ice Age. We can work to slow climate change. The Vikings are stuck in it.”
Adapted from a press release from Harvard University.
