Quantification and Visualization of In Situ Degradation at the World Heritage Site Bryggen in Bergen, Norway

Abstract

Environmental monitoring at the World Heritage Site of Bryggen in Bergen, Norway, has shown damaging settling rates caused by degradation of underlying archaeological deposits. Measurements of piezometric head, oxygen, and soil moisture content, as well as chemical analyses of water and soil samples are key elements of the environmental monitoring.

Groundwater monitoring and geochemical analyses reveal a complex and dynamic flow through the natural and anthropogenic stratigraphy. The preservation conditions within the organic archaeological deposits are strongly correlated with oxygen and soil moisture content, that are controlled by the groundwater flow conditions at the site. To quantify decay rates, it is thus essential to understand the wider hydrogeological context of the site. This paper presents recent advancements in quantifying decay rates in the saturated zone at Bryggen. The paper also shows that 3D geo-archaeological modelling can contribute to preservation management by visually combining results of geological, archaeological, geochemical, and hydrological investigations. This opens up for improved multidisciplinary understanding of preservation potential, thereby contributing to an improved protection of archaeological deposits in situ.

Keywords:

• in situ preservation
• groundwater
• geochemistry
• modelling
• monitoring
• visualization

The monitoring work at Bryggen is financed by the Directorate for Cultural Heritage in Norway, Riksantikvaren. This paper is part of a research programme on groundwater and cultural heritage. Contributions and comments of two anonymous reviewers are highly appreciated.

Additional information

Notes on contributors

Johannes de Beer

Johannes de Beer is hydrogeologist and team leader for Groundwater and Urban Geology at the Geological Survey of Norway in Trondheim. He has many years’ experience in urban groundwater management and modelling. His current research is focused on hydrogeological site characterization and risk-assessment of organic cultural deposits in urban areas.

Correspondence to: Johannes de Beer, Geological Survey of Norway (NGU), Leiv Eirikssons vei 39, PO Box 6315 Sluppen, 7491 Trondheim, Norway. Email: hans. [email protected]

Henning Matthiesen

Henning Matthiesen is senior researcher at the National Museum of Denmark. His research focuses on in situ preservation of archaeological remains. He has a background in chemistry and environmental monitoring.

Correspondence to: Henning Matthiesen, National Museum of Denmark, IC Modewegsvej 1, 2800 Kgs. Lyngby, Denmark.

Ann Christensson

Ann Christensson is senior advisor at the Directorate for Cultural Heritage in Norway and has a background in archaeology from the University of Bergen. She wrote her theses on material from excavations in Bergen, amongst them several from Bryggen and the surrounding area. She has for the last ten years been leading the monitoring programme for the archaeological deposits in Project Bryggen.

Correspondence to: Ann Christensson, Directorate for Cultural Heritage, Dronningensgate 13, Pb. 8196 Dep., 0034 Oslo, Norway.