Suchergebnisse

The logical foundations of different interpretations of the fundamental "hydrosphere" concept, widely used in the Earth sciences, are discussed. Five principal interpretations of the hydrosphere notion were identified: the World Ocean; the World Ocean and all surface land waters; all surface and ground waters on the Earth; all surface and ground waters, as well as waters of the atmosphere, including atmospheric moisture; all forms of water present on the planet. Based on the concept of the phase-shell structure of the Earth, it is logically most reasonable to define the hydrosphere as a shell of the Earth, which embraces all water bodies located between the atmosphere and the lithosphere (the World Ocean, lakes, rivers, swamps, temporary and permanent snow and ice cover). The hydrosphere does not include water vapor in the atmosphere and groundwater, which are components of other geospheres, i.e. the atmosphere and the lithosphere, respectively.

Based on the potentiometric measurements average fluorine concentrations for different phases of the hydrological regime were determined in water samples taken in 2018-2020 in the outlet of the Ob River: 0,103 mg/L in the winter low-water period, 0,079 mg/L in the spring - summer flood, and 0,095 mg/L in the summer - autumn low-water period. The present-day weighted average concentration of fluorine in the Ob River water (0,086 mg/L) closely corresponds to the values measured in 1954-1956 and 1976-1980 (0,090 and 0,084 mg/L, respectively), therefore the fluorine content of 0,08-0,09 mg/L could be taken as a natural background.

New data on the fluorine content in North Atlantic waters was obtained by the method of direct potenti-ometry with a fluoride ion-selective electrode. The measured fluorine concentration was equal to 1,27 0,03 mg/kg at F/Cl mass ratio of (6,59 0,11) · 10-5, which closely corresponds to the normal fluorine content in seawater. The totality of available data on the F/Cl ratio in different areas of the World Ocean suggests rather low variability of the fluorine content in seawater salts.