Environment in stone chamber of an unexcavated tumulus and preservation of buried relics: Part 1. Environmental monitoring for simulated tumulus

Abstract

Japan has many unexcavated tumuli, most of which were buried along with artifacts of precious cultural heritage. For such a tumulus, it is essential to understand how changes in its exterior environment affect its interior environment, and how those interior changes affect the deterioration of the relics buried in the stone chamber. In this study, an underground space was constructed in the forest of the Katsura Campus of Kyoto University to simulate the environment of an unexcavated tumulus, and long-term monitoring was implemented in the simulated stone chamber, including the temperature, humidity, water potential, wetness, and oxygen and carbon dioxide concentrations, along with metal corrosion tests. This article is focused on environmental monitoring, and the results demonstrate that the simulated tumulus has the general characteristics of the hygrothermal environments of an unexcavated tumulus that has small temperature fluctuation and near-saturation humidity. The ceiling of the simulated chamber condensed significantly from October to April, which is related to the variations of the ceiling and floor temperatures. Also, the wetness of the walls in the simulated chamber was affected by rainfall. The oxygen concentration in the simulated stone chamber varied in the range of 13%–19% in 2015, and the variation of carbon dioxide concentration in the simulated stone chamber was contrary to the oxygen concentration and varied in the range of 3%–9% in 2016. The oxygen concentration in the stone chamber was similar to that in the surrounding soil that decreased at times of rainfall, contrary to the fluctuations in the soil water content.

Spatial and temporal changes in microclimate affect disease distribution in two ancient tombs of Southern Tang Dynasty

“…Murals in tombs and caves are important cultural heritages that record civilizations and provide evidence for exploring the history of different eras and regions [ 1 , 2 ]. Deeply buried underground, tombs often exhibit unique environmental characteristics, such as stable temperature, high relative humidity, and a lack of ventilation and light inside the tombs, which is cut off from the exterior world before excavation [ [3] , [4] , [5] ]. After excavation, tombs undergo substantial environmental changes [ [6] , [7] , [8] , [9] ], such as drastic fluctuations in temperature and humidity.…”