Why did the Norse abandon their farms on Greenland? At https://phys.org/news/2022-03-rewriting-history-vikings-left-greenland.html … which is derived from
www.science.org/doi/10.1126/sciadv.abm4346 … Norse farmers arrived in Greenland during the Medieval Warm Period, turning up in the late 10th century AD. Their farms were abandoned in the early 15th century – and survived for a little over 400 years. The usual view is that the onset of cold weather in the first stages of the Little Ice Age made the colonies untenable. This idea ignores the fact the Norse managed to survive in Iceland, where an expansion of sea ice became a huge problem as far as contact with the mother country was concerned. Hence, the abandonment of the Greenland farms has been something of a mystery. Or open to speculation. The new research seems to be much in the same mode, making assumptions on evidence that might not be as damning as it is presented. A lake in southern Greenland provided a sediment core that provides information on aspects of the climate through Norse occupation. The sediment core goes back 2000 years, all the way to the Roman Warm Period. What they found is that the weather became drier. This is thought to have made it difficult to overwinter farm animals, leaving them weak. On the other hand, there is an elephant in the room. The 14th century outbreak of the Black Death. What with young people going back to the motherland, or Iceland, and a percentage of deaths via the plague, one can see how a small rural population would have dwindled, the survivors eventually leaving for good. The jury is still out on this one.
At https://phys.org/news/2022-03-rapid-glacial-advance-reconstructed-norse.html … we have a different piece of research on the Norse in Greenland. It is derived from a study published in the journal Geology , and plots glacial advances during the Norse occupation of Greenland. The rate of advance was surprising, we are told, as fast as modern glacial retreat. This informed a great deal of actual fieldwork – on foot to remote sites. During the Medieval Warm Period, there was a river running along the valley chosen for the research. It deposited sediment directly from the glacier in the upper valley into the lower valley, where the farms were situated, and eventually, into the fjord at the juncture of the valley. During the 12th and 13th centuries the glacier began to advance, at the rate of 115 metres annually. This is comparable to glacial retreat over recent years. The glacier reached its maximum as late as 1760, during the back end of the Little Ice Age. It then began to retreat as the northern hemisphere began to warm up. Since 1760 it has retreated 23 km.
The upshot is that the Norse still lived in Greenland while the glaciers advanced, as the Medieval Warm Period gradually came to an end. The farmers still carried on even though the glacier advance to within 5 km of the farm furthest from the sea. Glaciers were of course advancing in both Iceland and the mother country, Norway and Sweden, at the same time. Not so dramatically as on Greenland but it was not a phenomenon unknown to the Norse. Nowadays, there are a lot of icebergs in the fjord and coastal zone as the river meets the sea but back in the 12th and 13th centuries the glacial advance meant that water was being locked up as ice and not released as icebergs. The fjord would have been quite different from what it is nowadays. The mystery remains.