Title

T.S. SAKULINA (Sevmorgeo), S.N. KASHUBIN, O.V. PETROV (VSEGEI), A.F. MOROZOV (Rosnedra), N.A. KRUPNOVA, N.T. DERGUNOV, A.V. RAZMATOVA, S.N. TABYRTCA (Sevmorgeo), T.V. KASHUBINA, T.M. YAVAROVA (VSEGEI)

Deep structure of the Earth´s crust and the upper mantle of the North Chukchi Basin of the DSS Dream-­line Profile

Deep seismic sounding (DSS) studies with ocean bottom seismometers were conducted by FGU NPP Sevmorgeo for the British Petroleum in 2009. DSS Dream­line Profile having the length of 925 km is located in the East Siberian and Chukchi seas along the North Chukchi Basin. Vp and Vp/Vs velocity models of the Earth’s crust and uppermost mantle of the North Chukchi Basin were constructed using seismic data of these studies and fund data of the multichannel seismic (MCS) profiles RU2-­1350, CMP-­2 and ARS10Z01, partly coinciding with the direction of the DSS Dream­-line Profile. Crustal cross­section consists of sedimentary cover (Vp=1.6–1.9 km/s at the top to 4.8–5.6 km/s at the bottom, Vp/Vs from 1.9 to 2.4); intermediate (metasedimentary) complex (Vp 4.6–6.0 km/s, Vp/Vs=1.8–1.9); the upper crystalline crust (Vp 6.0–6.4 km/s, Vp/Vs 1.73–1.75); lower crystalline crust (Vp 6.6–7.2 km/s, Vp/Vs=1.73–1.74); uppermost mantle (Vp 8.0–8.1 km/s). The average thickness of the Earth’s crust along the Dream-­line Profile is about 28–30 km, and a significant part (7–16 km) corresponds to the sedimentary cover. Such velocity parameters and thickness of the North Chukchi Basin crust are typical of the continental crust of deep depressions.
Keywords: deep seismic sounding, North Chukchi Basin, converted waves, ray­tracing modeling, the Earth’s crust of the deep basins.