Deep seismic investigations in the Barents and Kara Seas

Combined reflection (CDP) and refraction/wide-angle reflection (DSS) studies were carried out along the 2-AR profile from the center of the Barents Sea across the Novaya Zemlya Island and the Kara Sea. A dense system of observations with intervals between the bottom stations of 10 km enables to determine detailed velocity models of the crust and uppermost mantle and to value of roles of CDP and DSS surveys in the studies. They are used also for a comparison between possibilities and limitations of different methods of the DSS data interpretation (1D solution, tomographic modeling, the Moho imaging and ray-tracing). The studies show the continental crust with average thickness of 35–37 km in the sea areas and of 40–45 km beneath the Novaya Zemlya. In the deep basins filled with 7–14 km thick sediments, the crystalline crust is reduced with the Moho rising. The crustal structure is complicated by fault zones which divide the crust in blocks with different tectonic regimes. The largest fault of listric form crosses the whole crust between the Novaya Zemlya and the South-Kara basin. Several rift grabens and faults are revealed in the basin basement. This confirms the idea that the basin formation started from narrow rift grabens. Beneath the Moho several inclined boundaries are traced down a depth of 60 km.