Applying 3D stratigraphic reconstruction to a large rescue archaeology site. A case study of the medieval and early modern submarine topography in Oslo, Norway

The site B8b in Oslo, Norway, measured over 10,000 cubic metres and was excavated by the Norwegian Maritime Museum (NMM) and the Norwegian Institute for Cultural Heritage Research (NIKU) in 2022–2023. This paper presents the workflow for the 3D reconstruction of the stratigraphic phases on NMM's part of the site. The challenges that come with 3D reconstructing a site of this size are discussed and compared to other sites where 3D stratigraphic reconstruction has been attempted. For this study, solid meshes of the stratigraphy were created in Blender, then integrated with other excavation data in ArcGIS PRO. The 3D dataset of the stratigraphy was subsequently used for analysing the inclination of the former seafloor and the relationship between the site's stratigraphy and finds such as a late medieval boat wreck.