Recognition of strong (М ≥ 6½) earthquake-prone areas in California has been performed using the modified version (FCAZm) of the original algorithmic system FCAZ (Formalized Clustering And Zoning). This system is the part of the Discrete Mathematical Analysis (DMA) – the original approach towards analysis of geological and geophysical discrete data, which was developed in the Geophysical Center of RAS. The recognition objects used by the system are represented solely by information on the earthquake epicenters. For the territory of California, the earthquake epicenters with M ≥ 3.0 were selected. Highly-seismic FCAZm-zones, recognized in California, agree well with the location of earthquake epicenters with М ≥ 6½. The epicenters of practically all strong earthquakes fall within the FCAZm-zones. The veracity of the recognized zones was confirmed by results of the control experiments «individual seismic history» and «complete seismic history». The FCAZm-zones have been compared with the ones earlier recognized by the classical EPA-method (1976) and by the initial version of the FCAZ system (2014). It was revealed that within California the area of the FCAZm-zones is twice smaller than the area of the EPA-zones. In addition, the FCAZm-zones better agree with the М ≥ 6½-earthquake epicenters than the EPA-zones. The results of this research allow to suggest the high veracity of the interpretation of FCAZm-zones as the strong earthquake-prone areas in California. The FCAZm-zones agree well with the classical EPA-zones and improve them, and make them clearer.
Application of GIS technologies
The algorithm of geoinformation modeling of assessment of suitability degree of sandstone dumps revegetation is developed. The algorithm is implemented for the territory of the coal mine, located in the south of Kemerovo Oblast. The combinations of conditions of the soil catena zones, the aspect and the slope determined by topography, are used as indicators of suitability degree. By means of GIS the space structure of habitats is defined and the map of suitability degree of dump habitats and surrounding area is constructed. Comparison of design data with the data of field geobotanical studies and results of the NDVI analysis, has yielded similar results. Therefore, the possibility of using geoinformation modeling for optimization of works in biological recultivation of coal dumps areas is shown.
Landslides are a complex phenomenon that is now widely spread all over the world and damages not only the economies of individual countries and regions, but also leads to human casualties. Conducting spatial regional analysis of landslide susceptibility can become a basis for making managerial decisions, helping the population, planners and engineers to reduce the consequences, losses and damage caused by modern or future manifestations of landslides. In the article methodical approaches to the spatial analysis of landslide susceptibility with the help of GIS are considered. The author gives the main terminology of this approach, the general scheme of its implementation, a detailed mathematical analysis apparatus and recommendations for its implementation. The author also gives recommendations on the choice of factors affecting the landslides for their use in spatial regional analysis.
Modeling geo objects and geo-processes
The article considers a number of factors that are not taken into account in interpretation the magnetic data, which often significantly reduces the degree of its reliability. It was proposed to apply the method of analytical continuation of the magnetic field downwards, developed by the author, to overcome the difficulties of solving the inverse problem (IP).
Digital elevation models (DEMs), including bathymetric models, are an essential component of geographic information systems (GIS) database for many purposes. GIS make it possible to create multiple layers characterizing different features of sea bottom and applying powerful tools of spatial data analysis and GIS mapping for practical purposes in marine geology and geomorphology, and also in cartography, palaeogeography, geoecology, hydroacoustics, etc. Digital elevation models of Barents and White seas are created from nautical charts of different scales. Isobaths (depth contours) on these charts were drawn manually from geologic, geomorphologic, and supplementary information (most recent at the time of map creation); theoretical views on landform genesis, its structural belonging, palaeogeographic conditions and recent development features were also taken into account. Digitized depth contours were interpolated to the medium-resolution (100-200 m) gridded DEM. The original interpolation algorithm, proposed by authors, was used; this algorithm processes contours as vector objects, which allows to preserve all shape features delineated by initial isobaths. Comparison of DEM elevation with echo sounding data shows good similarity between elevation values.
Different aspects of seismic information processing procedures have a significant impact on the structure of geological models created in geoinformation systems. In the paper, systems of linear equations and their solutions under construction in problems of seismic signal correction, in particular, arrival times and amplitudes, are studied. In the construction of solutions, two approaches were considered: the iterative process of sequential refinement of factor estimates and the application of heuristic conditions that ensure the uniqueness and stability of the solution. It is shown that the iterative process, based on the separate estimation of factors, leads to the appearance of long period spatial components, determined by the ratio of the length of the seismic streamer to the total length of the observation profile. The components are a consequence of the applied process of factors estimation process, and the reason for their appearance is due to the weak coupling of the zero-manifold vectors of the corresponded linear operator on different parts of the profile. To eliminate such components, large volumes of a priori data are required. Otherwise, the subsequent construction of geomodels will absorb these distortions. An alternative way that eliminates the appearance of such components is to consider all observations and use special conditions that allow us to link different parts of the profile and significantly reduce the amount of necessary a priori information required to determine an unambiguous solution to the problem.
Investigation of Danube River delta changes for 2002-2016 and comparison with delta dynamics at precede decades has been made. Study results has shown that Danube delta prolongs its protruding, its area increase for 11,6 km2; growth of delta sea edge is 11,91 km2, and erosion 10,31 km2. Increase of delta area is concentrate in Kilia part of delta, because the Kilia branch provide with the most part of sediment run off; delta part between Sulina and St/Georg branches is exposed by erosion. Temp of delta growth in comparison with 1972-2002 period has increased twice, and temp of erosion decreased twice. High resolution satellite images show that previous delta geosystems – reed plavni –begin intensive using. Meliorated territories turned into agricultural fields, rice plantations are created, fish farms, plantations for reed growth and cutting, for forest growth were appeared. All of them are shown at the map of natural and anthropogenic geosystems, compiled for the first time.