Predicting the loss of organic archaeological deposits at a regional scale in Greenland

Jørgen Hollesen,Andreas Westergaard-Nielsen,Jakob Abermann,Rasmus Fenger-Nielsen,Bo Elberling,Henning Matthiesen

doi:10.1038/s41598-019-45200-4

Jørgen Hollesen, Andreas Westergaard-Nielsen + Show 4 more

Open Access

https://doi.org/10.1038/s41598-019-45200-4

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Abstract

Across the Arctic, microbial degradation is actively destroying irreplaceable cultural and environmental records that have been preserved within archaeological deposits for millennia. Because it is not possible to survey the many sites in this remote part of the world, new methods are urgently needed to detect and assess the potential degradation. Here, we investigate organic deposits at seven archaeological sites located along the dominating west-east climatic gradient in West Greenland. We show that, regardless of age, depositional history and environmental conditions, all organic deposits are highly vulnerable to degradation. A state-of-the-art model that simulates the effect of future climate change on degradation indicates that 30–70% of the archaeological fraction of organic carbon (OC) could disappear within the next 80 years. This range reflects the variation within the climatic gradient and the future climate scenario applied (RCP 4.5 and RCP 8.5). All archaeological deposits are expected to experience a substantial loss, but the most rapid degradation seems to occur in the continental inland areas of the region, dominated by dry and warm summers. This suggests that organic remains from the Norse Viking Age settlers are especially under threat in the coming years.

Highlights

Archaeological sites in the Arctic contain extraordinarily well-preserved organic deposits that provide unique evidence of past humans[1,2,3,4] and the ecosystems in which they lived[5,6,7,8]
Based on results from previous degradation studies of organic archaeological materials[10,13,15], we focus on the oxic degradation of organic deposits that contain important residues of human subsistence and in which various types of artefacts are embedded
The seven archaeological sites are located along a transect stretching from the sea in the West and approx. 120 km inland towards the Inland Ice Sheet to the East (Fig. 1)

Summary

Introduction

Archaeological sites in the Arctic contain extraordinarily well-preserved organic deposits that provide unique evidence of past humans[1,2,3,4] and the ecosystems in which they lived[5,6,7,8]. We investigate the physical and chemical properties of seven different organic archaeological deposits in the Nuuk region in Southwest Greenland and use the results to develop a model setup that can be used to predict current and future soil temperatures, water content and loss of OC.

Results

Conclusion