The Impact of Climate Change on an Archaeological Site in the Arctic

Climate change may accelerate the degradation of archaeological sites in the Arctic and lead to a loss of important historical information. This study assesses the current preservation conditions and the processes controlling the physical and chemical stability of the Qajaa kitchen midden in western Greenland. Currently, the site is well protected by low ground temperatures, permafrost and a high water/ice content, keeping the deposits anoxic. Based on 5 years of monitoring data, degradation experiments and model simulation, our results suggest that the combined effects of permafrost thaw, thermal and hydrological erosion and oxygen exposure may lead to substantial loss of archaeological evidence before the end of the 21st century.     

Degradation of Archaeological Wood Under Freezing and Thawing Conditions—Effects of Permafrost and Climate Change

The degradation of archaeological wood at freezing and thawing temperatures is studied at the site of Qajaa in West Greenland through a combination of environmental monitoring, measurement of oxygen consumption and microscopy of wood samples. Permanently frozen wood is still very well preserved after 2–4000 years, while wood samples that thaw every summer show attack by soft rot and an average density loss of 0.1 g cm^–3 (corresponding to 25% of the dry mass) over the past 27 years. Future increases in temperature may increase the decay rate significantly (Q₁₀ = 4.2 at 0–10°C) but the effects on site depend on local hydrology.     

The Future Preservation of a Permanently Frozen Kitchen Midden in Western Greenland

Abstract

Archaeological materials may be extraordinarily well preserved in Arctic areas, where permanently frozen conditions in the ground slow down the decay of materials such as wood, bone, ?esh, hair, and DNA. However, the mean annual air temperature in the Arctic is expected to increase by between 2·5 to 7·5°C by the end of the twenty-?rst century. This may have a signi?cant warming effect on the soil and could lead to permafrost thaw and degradation of currently frozen archaeological remains. Here we present a four-year monitoring and research project taking place at Qajaa in the Disko Bay area in West Greenland. Qajaa is a large kitchen midden, containing frozen remains from 4000 years of inhabitation, from when the ?rst Palaeo-Eskimos entered Greenland, until the site was abandoned in the eighteenth century. The purpose of the project is to investigate current preservation conditions through ?eld and laboratory measurements and to evaluate possible threats to the future preservation.

Preliminary results show that the archaeological material at Qajaa is still very well preserved, but some microbial decay is observed in the exposed wooden artefacts that thaw every summer. Maximum temperatures are above 0°C in the upper 40–50 cm of the midden and between 0 and ?2°C down to 3 m depth. Thereby the permafrost may be vulnerable to quite small increases in air temperatures. Laboratory measurements show that the decay of the archaeological wood in the midden is temperature-dependent, with rates increasing 11–12% every time the soil temperature increases 1°C. Moreover, the soil organic material produces heat when decomposed, which could have an additional warming effect on the midden. At the moment the water or ice content within the midden is high, limiting the subsurface oxygen availability. Threats to the future preservation are related to further thawing followed by drainage, increased oxygen availability, microbial decay of the organic material, and heat production.     

URBANIZATION IN THE USSR: PROBLEMS OF SPATIAL DIFFERENTIATION

The process of formation of settlement systems “in the USSR is conceptualized as proceeding at eight levels of a hierarchy corresponding to the system of economic regions, from a national system down to rayon-level systems. An important element in the present process of urbanization is the formation of urban agglomerations. The fact that these urban entities still lack juridical or even statistical status deprives urban and economic planners of a valuable data base for planning purposes so that the agglomerations often evolve in undesirable, uncoordinated ways. Greater attention needs to be given to the study of the internal structure of urban entities, a field neglected by Soviet population geographers. An undesirable tendency in Soviet agglomerations is to aim at continuously built-up territory, thus converting agglomerations into traditional compact cities, instead of making provision for open spaces for use in agriculture and forestry, recreation and communications.