Volume 24, Nº 3 (2024)

The 85∘E Ridge associated by the free-air gravity low into a meridional orientation. However, there are two gravity lows south between of 4∘N and 3∘S the nature of which remains a subject of discussion. This article presents the results of density and magnetic modeling based on the data of the expedition SO258/2 with RV Sonne. An analysis of the modeling results with seismic data showed that the nature of gravity lows is associated with the process of serpentinization, and these lows are not a continuation of the 85∘E Ridge.

The height of sea waves is one of the most important characteristics describing the wave climate of the ocean. At the present, the main radar for remote measurement of wave heights is an altimeter. Measurements are performed at the vertical sounding (incidence angle equal to zero). The Brown model was developed to describe the waveform of the reflected impulse at the vertical sounding. There is no theoretical model for the case of oblique sounding. In the Kirchhoff approximation, the theoretical task about waveform of the reflected impulse at oblique sounding was considered. In the result of the investigation, the analytical formula for the waveform of the reflected impulse for oblique sounding at the small incidence angles (< 12◦) for a microwave radar with a narrow antenna beam was obtained. The waveform of the reflected impulse depends on the width of antenna beam, incidence angle, impulse duration, significant wave height (SWH), altitude of the radar, mean square slopes of large-scale, in comparison with radar wavelength, sea waves. It is shown that possibility exist to retrieve SWH using waveform the reflected impulse at the oblique sounding.

For the Middle Urals and adjacent territories of the East European and West Siberian platforms within geographic coordinates from 56∘ to 60∘ northern latitude and from 54∘ to 66∘ east longitude, the structural features of the anomalous magnetic and gravitational fields were studied and maps of separated anomalies were constructed for three layers of the Earth's crust. Using original parallel algorithms for solving forward and inverse problems of gravimetry and magnetometry, a density model of the lithosphere and sources of magnetic anomalies in the Earth's crust were constructed. The results of modeling the sources of magnetic anomalies in the Earth's crust are compared with the density model in order to study the differences in the deep structure of the western and eastern sectors of the Ural fold system, as well as the zones of junction of the Paleozoic Uralian orogen with the ancient East European and Epi-Gercinian West Siberian platforms.

This article describes a new, efficient, and quick method for conducting field measurements to create a three-dimensional model of ice formations. The method involves the use of a total station geodetic instrument, a powerful LOZA georadar, and an unmanned aerial vehicle with a camera. The technique is especially useful for measuring unstable ice formations with horizontal dimensions ranging from 50 to 300 meters. Examples of applying this method during winter fieldwork on the Sakhalin Island's eastern shelf in 2019 are provided.

The results of a comprehensive analysis of fault tectonics of the Kola Peninsula, carried out on a regional scale, are considered. Based on a digital relief model, generalized for various scale levels, lineaments were identified manually and automatically. The results obtained in combination with literature data made it possible to carry out tectonophysical reconstructions using the Hancock model. Based on the results of these reconstructions, the proposed areas of tectonic structures were identified that had the greatest hydraulic activity at the time of the introduction of mafic-ultrabasic massifs and dike complexes of pegmatite belts, which are associated with ore deposits of scarce types of strategic minerals of the Kola Peninsula (copper, nickel, chromium, rare metals, etc.) The areas were identified, promising for the discovery of new ore objects.

The article presents the results of comparative analysis of the main geourbanistic processes in the North-Eastern Caucasus. Modern concepts and approaches in the works of Russian and foreign researchers to the functional zoning of urban areas as the most important tool for their regulation and management are revealed. The period 1986–2023 reveals a significant increase in the area of built-up territories in large cities. The most active rates of construction occurred in Makhachkala and Grozny. In the larger cities considered in the article, the last decade has seen an increase in the area of residential and public-business zones. The current structure of land funds in Makhachkala and Nazran is dominated by agricultural land, while Grozny also has a high share of residential area. It is shown that the areas of recreational zones in the cities under study are insufficient both to meet the recreational needs of residents and for the development of tourism. It is proved that it is necessary to increase the area of recreational zones at the expense of agricultural land, and in Grozny also by reducing the industrial-engineering zone. Assessment of the areas of urban forested territories and their cartographic visualization revealed an insufficient level of greening and uneven distribution of forest areas. Very low level of greening was found in Nazran (less than 1%) and Makhachkala (6%). Taking into account the identified features and trends in the ratio of functional zones in large cities of the North-Eastern Caucasus, recommendations are given to optimize functional zoning by regulating the ratio of functional zones, green spaces, including vertical landscaping, introduction of elements of creative linguistic landscapes. Special attention is paid to providing a diversity of recreational areas.