Structure and sediment distribution in the western Bering Sea

摘要: Abstract Eleven seismic reflection profiles across Shirshov Ridge and the adjacent deep-water sedimentary basins (Komandorsky Aleutian Basins) are presented to illustrate sediment distribution in western Bering Sea. A prominent reflecting horizon, Reflector P (Middle—Late Miocene age), is observed throughout both Komandorsky Basins at an approximate subbottom depth of 1 km. This reflector also present, places, on flanks along crest Ridge. The thickness sediments beneath significantly different within two abyssal basins. In Basin, total acoustic basement (basalt?) about 4 km, while Basin 2 Ridge, a Cenozoic volcanic feature that separates Basins, asymmetric bathymetric ridge characterized by thick its eastern flank steep scarps side. southern portion has more structural relief includes several deep, sediment-filled summit. Velocity data from sonobuoy measurements indicate average compressional wave velocity 5.90 km/sec. value considerably larger than velocities measured for northwestern (about 5.00 km/sec) central (5.40–5.57 km/sec). low-velocity may be volcaniclastic or other indurated overlying true basaltic basement. refracting horizon with similar (4.6–5.0 as dips steeply Siberian continental margin, reaching maximum 8 welt base margin result loading tectonic depression prior Late time.