Buried in water, burdened by nature-Resilience carried the Iron Age people through Fimbulvinter.

Markku Oinonen,Jukka Palo,Kristiina Mannermaa,Samuli Helama,Laura Arppe,Antti Sajantila,Maria Lahtinen,Heli Huhtamaa,Kati Salo,Hervé Bocherens,Teija Alenius,Heli Etu-Sihvola,Anna Wessman,Päivi Onkamo,Santeri Vanhanen,Tarja Sundell

doi:10.1371/journal.pone.0231787

Abstract

Levänluhta is a unique archaeological site with the remains of nearly a hundred Iron Age individuals found from a water burial in Ostrobothnia, Finland. The strongest climatic downturn of the Common Era, resembling the great Fimbulvinter in Norse mythology, hit these people during the 6th century AD. This study establishes chronological, dietary, and livelihood synthesis on this population based on stable carbon and nitrogen isotopic and radiocarbon analyses on human remains, supported by multidisciplinary evidence. Extraordinarily broad stable isotopic distribution is observed, indicating three subgroups with distinct dietary habits spanning four centuries. This emphasizes the versatile livelihoods practiced at this boundary of marine, freshwater, and terrestrial ecosystems. While the impact of the prolonged cold darkness of the 6th century was devastating for European communities relying on cultivation, the broad range of livelihoods provided resilience for the Levänluhta people to overcome the abrupt climatic decline.

Highlights

Mediterranean historical sources identify a mystery cloud obstructing the Sun at AD 536/537 [1]
Broad carbon (C) and nitrogen (N) isotopic ratio distribution is observed in the human bone collagen of the Levanluhta individuals (Table 1, Fig 2, Table D in S4 Appendix)
A chronological, dietary and livelihood synthesis is established based on radiocarbon and stable isotopic studies of human bone remains on the Iron Age population excavated from the unique spring burial of Levanluhta

Summary

Introduction

Mediterranean historical sources identify a mystery cloud obstructing the Sun at AD 536/537 [1]. The year without the Sun is observed in tree rings as a negative growth anomaly throughout the Northern Hemisphere (NH)[2]. An even larger tree-growth decline is observed during the AD 540s, and discussion of the anomaly has evolved from a single mystery cloud to a decade-scale climatic catastrophe as a result of multiple volcanic eruptions of AD 536–550. Buried in water, burdened by nature—Resilience carried the Iron Age people through Fimbulvinter data collection and analysis, decision to publish, or preparation of the manuscript

Methods

Results

Discussion

Conclusion