Structure and density configuration of Germany’s subsurface: 3-D-Deutschland, an updated three-dimensional lithospheric-scale model

With this study we revise and improve the three-dimensional lithospheric-scale structural and density model of Germany (3-D-D). Major shortcomings of this model resulted from joining three regional 3-D models that were poorly covered by data at their margins. Merging into a larger model revealed structural inconsistencies in these “marginal” domains. In order to resolve discrepancies between the units in a more consistent way we integrate newly available data from seismic reprocessing, tomography, and use 3-D gravity modelling to improve the fit between the modelled and observed gravity. The recently initiated reprocessing of the DEKORP seismic profiles, for example, in the region of the Rhine Graben by the federal geological survey of Hesse (Bär et al. in prep.), indicate that previous assumptions on sediment thickness in certain regions, as well crustal structure and Moho depth need to be revised. We integrate this new structural information together with density variations derived from mantle seismic tomography (CSEM Europe, Fichtner et al., 2018; LSP_Eucrust1.0, Lu et al. 2018) and analyse the updated density distribution against the more detailed Bouguer gravity anomaly map of Germany (Skiba, 2011). The update of the 3-D-D model is important for ongoing research in seismic hazard assessment in that it serves as a basis for thermal and rheological modelling helping to relate observed seismicity with spatial variations in strength. The model provides a data-consistent background for regional studies on sustainable use of geothermal energy and on the suitability of sites for the underground storage of radioactive waste or of CO2.