Marine seismic investigations in the Baltic Sea with RV Maria S. Merian
Report of the project:
In the course of RV Maria S. Merian expedition MSM52 BGR acquired high resolution multi-channel seismic data in the Baltic Sea within the framework of the project BalTec (coordinator Prof. Hübscher/University of Hamburg). The seismic measurements were supplemented by wide angle seismics, gravity, bathymetry and sediment echosoundings.
These new seismic profiles reveal high depth penetration and a unique vertical resolution of the acquired seismic profiles imaging the Palaeozoic up to Quaternary strata and the tectonic inventory of the southern Baltic Sea. Several profiles across the Tornquist Fan up to the Baltic Shield east of Gotland image deeper parts of the continental crust. Previous studies were either focussed on imaging of deeper crustal parts and the Moho or they image the Mesozoic strata of the basin infill. Compared to these older data the new data are characterized by good depth penetration of several kilometers and optimum vertical resolution. This allows for the interpretation of both top and base of the Zechstein salt for larger areas in the German Baltic Sea sector.
North of Rügen the data cover a gap between two previous surveys which were conducted between 1975 and 1987 (GO Petrobaltik). This dataset was used within the framework of a previous BGR project (SASO – 1997) to derive a structural atlas for the southern Baltic Sea. The new seismic profiles connect to several wells in the survey area to allow for stratigraphic calibration and implementation of previous interpretations.
The recently acquired data are of great value in the process to derive a subsurface model for the North German Basin and to extend it into the area of the Baltic Sea. Additionally, the data allow for better resolution of Palaeozoic and Neogene subsurface structures east of Rügen Island and to close still existing stratigraphic interpretation gaps. Sediment echosounding data with a depth penetration of about 100 m additionally image the youngest sediments of near surface structures with high resolution. Combining this with the seismic data imaging deeper structures of the basin allows studying both the influence of reactivated deep reaching palaeozoic fault systems on neotectonic structures and possible fluid migration pathways within research projects at the University of Hamburg.
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Partner: University of Hamburg
Literature:
Ahlrichs, N., Hübscher, C., Noack, V., Schnabel, M., Damm, V. and Krawczyk, C.M., 2020. Structural Evolution at the Northeast North German Basin Margin: From Initial Triassic Salt Movement to Late Cretaceous-Cenozoic Remobilization. Tectonics 39, e2019TC005927, doi:10.1029/2019TC005927
Schnabel, M., Noack, V., Ahlrichs, N. and Hübscher, C., 2021. A comprehensive model of seismic velocities for the Bay of Mecklenburg (Baltic Sea) at the North German Basin margin: implications for basin development. Geo-Marine Letters 41, 20, doi:10.1007/s00367-021-00692-w
Warwel, A., Hübscher, C., Ahlrichs, N. and Schnabel, M., 2022. New insights into tunnel valley locations and Cenozoic exhumation in the southwestern Baltic Sea based on Machine Learning aided seismic refraction tomography. Marine Geophysical Research 43, 35, doi:10.1007/s11001-022-09492-y