Rewriting the history books: Why the Vikings left Greenland

The abandonment of successful settlements in southern Greenland in the early 15th century is one of the great mysteries of medieval history. The colonies were unsustainable because of the Little Ice Age's colder temperatures. New research led by the University of Massachusetts Amherst and published recently in Science Advances upends that old theory. It wasn't dropping temperatures that helped drive the Norse out of Greenland.

The Eastern Settlement of the Norse was a place where they cleared the land of shrubs and planted grass for their livestock. The population of the Eastern Settlement peaked at around 2000 people, but fell quickly. For decades, anthropologists, historians and scientists have believed that the demise of the Eastern Settlement was due to the Little Ice Age, a period of extremely cold weather in the North Atlantic.

Raymond Bradley, the University distinguished Professor of geosciences at the University of Massachusetts-Amherst and one of the paper's co- authors, points out that before this study, there was no data from the actual site of the Viking settlements. The ice core data that previous studies had used to reconstruct historical temperatures was taken from a location that was over 1,000 kilometers to the north and over 2,000 meters higher in elevation. The results were surprising when they did.

Bradley and his colleagues traveled to a lake called Lake 578, which is close to a large group of farms in the Eastern Settlement. They spent three years gathering samples from the lake, which was a continuous record for the past 2,000 years.

If you have a complete enough record, you can link the changing structures of the lipids to changing temperature. A second marker, derived from the waxy coating on plant leaves, can be used to determine the rates at which the grasses and other livestock-sustaining plants lost water due to evaporation. It's an indicator of how dry the conditions were.

While the temperature barely changed over the course of the Norse settlement of southern Greenland, it became steadily drier over time.

In a good year, the animals were often so weak that they had to be carried to the fields after the snow melted. The consequences of a dry spell would have been severe. The Eastern Settlement may be unsustainable due to an extended dry spell and other economic and social pressures.

Scientists at Smith College and the University at Buffalo contributed to the research which was supported by the National Science Foundation, the Geological Society of America, and the Swiss National Science Foundation.

More information: Boyang Zhao et al, Prolonged Drying Trend Coincident with the Demise of Norse Settlement in Southern Greenland, Science Advances (2022). DOI: 10.1126/sciadv.abm4346. www.science.org/doi/10.1126/sciadv.abm4346 Journal information: Science Advances Citation: Rewriting the history books: Why the Vikings left Greenland (2022, March 23) retrieved 23 March 2022 from https://phys.org/news/2022-03-rewriting-history-vikings-left-greenland.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.