Vikings abandoned the Greenland settlement due to sea-level rise, finds study

During this period, up to 75 percent of the Viking settlement was found to be within a thousand meters of the flooding area. 

The region's changing landscape would have made it difficult for Vikings to survive. Previous research estimated the factors that contributed to their departure, such as "social unrest, economic turmoil, political issues, and environmental change."

"Alongside these other challenges. This likely led "to a tipping point before they abandoned the settlement," said Marisa J. Borreggine, lead author of the study, in a statement.

Underlying factors contributed to this sea-level rise

The departure of the Vikings coincided with the start of the Little Ice Age. The authors emphasize that while this period would indicate ice growth, the opposite was occurring at Greenland's Eastern Settlement.

The study looked at past geomorphological and paleoclimate data, as well as ice-sheet growth modeling. This contributed to the conclusion about sea-level rise.

“There's already a background trend of sea-level rise upon Viking arrival in the Eastern Settlement. It's been rising for a few thousand years. But there's also a local effect: Crustal subsidence, or the sinking of land, and the gravitational pull of water toward the growing ice sheet," the statement explained.

The researchers concluded that the sea level rose due to various factors such as gravity and the sinking of Greenland's land mass. All of these factors contributed to the settlement's vulnerability to flooding.

The study has been reported in the journal Proceedings of the National Academy of Sciences (PNAS).

Study abstract:

The first records of Greenland Vikings date to 985 CE. Archaeological evidence yields insight into how Vikings lived, yet drivers of their disappearance in the 15th century remain enigmatic. Research suggests a combination of environmental and socioeconomic factors, and the climatic shift from the Medieval Warm Period (~900 to 1250 CE) to the Little Ice Age (~1250 to 1900 CE) may have forced them to abandon Greenland. Glacial geomorphology and paleoclimate research suggest that the Southern Greenland Ice Sheet readvanced during Viking occupation, peaking in the Little Ice Age. Counterintuitively, the readvance caused sea-level rise near the ice margin due to increased gravitational attraction toward the ice sheet and crustal subsidence. We estimate ice growth in Southwestern Greenland using geomorphological indicators and lake core data from previous literature. We calculate the effect of ice growth on regional sea level by applying our ice history to a geophysical model of sea level with a resolution of ~1 km across Southwestern Greenland and compare the results to archaeological evidence. The results indicate that sea level rose up to ~3.3 m outside the glaciation zone during Viking settlement, producing shoreline retreat of hundreds of meters.