Deep Structures of the Circumpolar Arctic

The deep model of the Earth’s crust and upper mantle of the Arctic basin is represented by a series of velocity sections along the DSS profiles and a set of maps showing the thickness of the sedimentary cover, the thickness of the Earth’s crust as a whole and the distribution of the continental and oceanic types of the Earth’s crust in the Circumpolar Arctic. Crustal Thickness Map is based on results of deep seismic studies and gravity field anomalies in the Circumpolar Arctic. Over 300 profiles of total length of about 140,000 km and equations of correlation, which link the depth of the Moho discontinuity occurrence with Bouguer anomalies and the topography, were used for the map compilation. Correlation sketch map of crustal types, which differ in velocity and density parameters, structure, and total crust thickness, has been compiled based on the data of deep seismic studies on continents and in oceans. The sketch map of crustal types distribution, which was compiled based on seismic profiles in the Arctic, demonstrates the position of the oceanic and continental crust in the structures of the Circumpolar Arctic. Summary geotransect is composed of DSS seismic line fragments and supplemented with density modelling. The geotransect demonstrates structure of the Earth’s crust and upper mantle along the line 7600 km long, which crosses the continental crust of the East European Platform, Barents-Kara shelf seas, Eurasian Basin oceanic crust, reduced crust of the Central Arctic Submarine Elevations, shelf seas of Eurasia passive margin, and crust of the Chukotka-Kolyma folded area.