Geophysical study of the Earthʼs crust (Northern regions of Russia and the Arctic sea shelf)

Abstract

Research subject. The results of the geological and geophysical study of the Earth’s crust on the territory of two regions are presented: the northwestern part of the East European Platform and the adjacent water area, as well as the waters of the East Siberian, Chukchi Seas and the Russian eastern sector of the Arctic Ocean, including the Lomonosov ridge and the Mendeleev–Alpha rise. The research is focused on mapping the Moho, the thickness and type of the Earth's crust necessary to substantiate the outer boundary of the continental shelf.Materials and methods. The authors’ original materials obtained during the processing of gravimetry and magnetometry data in the VECTOR system were used. Based on the relationship between gravity anomalies and density variations of rocks, the shape, size of the studied objects, and their deep mutual position are characterized.Results. The constructed schemes and profiles of the deep structure of the Earth's crust, obtained using the VECTOR method, were tested using the European Moho global seismic model. The positive forms of the Moho section and the raised parts of the shelf surface correspond to the positive anomalies of the transformed gravitational field. The spread of the structure of the field of continental anomalies in the Pevek–Anadyr area to the marine part of the territory under consideration can indirectly confirm the belonging of the Lomonosov Cr., the Mendeleev and Alpha ridges to the continental type of crust.Conclusion. Global, i.e., related to the territory of the globe, three-dimensional models of Moho allow us to expand and deepen the amount of knowledge about the features of the shelf structure. Geopotential fields in the VECTOR system display the tectonics of the studied environment systematically and comprehensively compared to is representation according to the scheme of profile seismic studies.