Bottom Sediments of the Caspian Sea as an Indicator of Changes in Its Water Regime

Qualitative changes in the Caspian Sea water regime for the last 20–25 kyr are analyzed based on studying the particle-size distribution, the composition of clay minerals, the mineral composition of the coarse clastic fraction, and the magnetic susceptibility of deep-sea bottom sediments.     

On the use of unmanned aerial vehicles for high-precision measurements of the Earth’s magnetic field

A brief account of the evolution of Russian airborne geomagnetics is given. It is shown that the development of aeromagnetic systems based on unmanned aerial vehicles (UAVs) is of great interest. This paper presents theoretical and experimental data that concern the development of the optimal UAV layout in order to create a UAV-based aeromagnetic survey system using a new-generation optically pumped quantum rubidium aeromagnetometer. The new UAV-based aeromagnetic system is planned for use for high-precision aeromagnetic surveying at low altitude (30 m and more) for geological, engineering, and environmental applications.     

Magnetic Susceptibility of Deep-Water Sediments of the South and Middle Caspian Sea

The dependence of magnetic susceptibility () of bottom sediments from the Caspian Sea on the composition of magnetoactive minerals contained in the heavy subfraction of fine-grained sand (0.125–0.100 mm) was established. Changes in the curve shape and value reflect a pulsating pattern of the input different (in magnetic properties) magmatic and metamorphic clastic minerals into sediments, as well as different intensities of the formation of authigenic magnetoactive iron sulfides under conditions of the multiple alternation of transgressive and regressive phases in marine basins. Values of and shapes of curves for the studied sedimentary sequences show that sediments in the South and Middle Caspian basins are characterized by different specific features.