Recovery of the Historical Polish Marine Gravity Data for the Baltic Sea

Modern marine gravity surveys are very costly and time-consuming. In the 1960s to 1980s, many marine gravity measurements were carried out in the southern and eastern Baltic Sea, mainly with the support of the research infrastructure of the Soviet Union. During the period of independence from the Soviet Union and transformation of the political system, much of these older data remain forgotten or not fully used. Now, it is scientifically and economically justified to reactivate these historical data so that they can supplement the modern surveys. This study presents the historical Polish marine gravity data, which were measured during four campaigns: Zaria, Jan Turlejski, Petrobaltic, and Ustka-Rozewie in 1971–1981 in the southern Baltic Sea. The datasets were transformed to modern geodetic and gravity reference frames, taking into account the available documentation. Next, a simple procedure was proposed for the determination of grid resolution, and the gridded 1′×1′ free-air and Bouguer anomalies were calculated for each survey. The resulting gridded anomalies were validated by three global geopotential models: EGM2008, EIGEN6c4, and GECO. Additionally, depths measured during the survey were validated using the ETOPO 2022 bathymetric model.