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This paper presents field results and analysis of iceberg towing experiments performed in the Barents and Kara Sea in 2016-2017. For the first time ever in the industry, this research was based on a complex study of the icebergs origin and properties. For that purpose prior to the trials outlet glaciers of Novaya Zemlya, Franz Josef Land and Severnaya Zemlya were examined with airborne radar that allowed to measure their thickness and to build 3D models. Satellite remote sensing data were used to derive glacier fronts position, ice surface flow velocity, changes of glacier margins, and parameters of iceberg distribution. The data on the flow rates of the main glaciers were compared with the satellite beacons equipped with GPS (ARGOS) installed on several glaciers. Empirical relationships were derived to determine the mass and geometry of icebergs based on instrumental measurements and airborne data in the Barents and Kara seas. All this information was used to estimate iceberg towing possibilities in different conditions, analyze obtained data and deeper understand the process. Influence of oscillations during the towing process was studied. For a wide range of towing speeds, drag force coefficients were determined for icebergs of various sizes and shapes. Experimental iceberg towing operations performed in ice fields during the early stages of ice formation are described. These works were conducted in October 2017 in the Kara sea. Limitations of iceberg towing under different ice conditions are determined and discussed. Technological features of towing operations within negative air temperatures and the presence of sea ice are also highlighted.

The FSBI AARI is the leading State Scientific Center of Russia, which is involved in studying the natural environment of the Polar Regions and its impact on human activity for over a century. In the last 30 years, the new sphere of activity, dealing with the specialized metocean (including ice) surveys for the purpose of Arctic Offshore Development was successfully developed here. For the most important Arctic Offshore projects the full set of these specialized studies was conducted by the Institution. The paper gives an overview of AARI’s scientific and applied scope and tasks, a general chronology of the surveys on the Russian Arctic Shelf since 1990-s, a description of the main study methods, and an overview of the main results of studies for the last ten years (2012-2021). It is demonstrated that the role of detailed ice and metocean surveys is often determinative in sense of design and construction of Arctic Offshore objects.

Liquid–liquid equilibria in the H2O–HNO3–Eu­(NO3)3–Gd­(NO3)3–tributyl phosphate (TBP) system and in two H2O–HNO3–Ln­(NO3)3–TBP (Ln = Eu, Gd) subsystems have been investigated at 298.15 K in a wide range of nitric acid and rare earth elements (REEs) concentrations. The total compositions of the extraction systems and the content of REEs and nitric acid in equilibrium phases are presented. Densities of solutions in two subsystems have been measured. The distribution coefficients of REEs and nitric acid and the separation factor of REEs in equilibrium phases have been determined. The obtained experimental data can be further used for thermodynamic modeling of systems that are promising for the extraction separation of REEs.

Activity of water in aqueous solutions containing sulfuric acid and uranyl sulfate has been determined at 298.15, 310.65, and 323.15 K by means of the apparatus AQUALAB 4TE. The data obtained, along with literature information about activity of water and solid–liquid equilibria in the H2O–UO2SO4 and H2O–H2SO4–UO2SO4 systems, were used to develop a thermodynamic model of the ternary system mentioned. The resulting model, employing Pitzer–Simonson–Clegg (PSC) equations to represent the properties of a liquid phase, is valid within a wide range of temperatures and concentrations. Apart from introducing novel experimental data and a thermodynamic model, the reported study discusses advantages and disadvantages of the PSC-based thermodynamic descriptions of the H2O–H2SO4 subsystem presented in the literature.