caa a22 4500 477047955 CHVBK 20180405111335.0 cr unu---uuuuu 170330e19961001xx s 000 0 eng 10.1007/BF01089694 doi (NATIONALLICENCE)springer-10.1007/BF01089694 Modelling shear waves in OBS data from the Vøring basin (Northern Norway) by 2-D ray-tracing [Elektronische Daten] [P. Digranes, R. Mjelde, S. Kodaira, H. Shimamura, T. Kanazawa, H. Shiobara, E. Berg] Three component recordings from an array of five ocean bottom seismographs in the northwestern part of the Vøring basin have been used to obtain a 2-D shear-wave (S-wave) velocity-depth model. The shear waves are identified by means of travel-time differences compared to the compressional (P) waves, and by analyzing their particle motions. The model has been obtained by kinematic (travel-time) ray-tracing modelling of the OBS horizontal components. The shear-wave modelling indicates that mode conversions occur at several high velocity interfaces (sills) in the 4-10 km depth range, previously defined by a compressional-wave velocity-depth model using the same data set. An averageV p /V s ratio of 2.1 is inferred for the layers above the uppermost sill, indicative of both poorly consolidated sediments and a low sand/shale ratio. A significant decrease in theV p /V s ratio (1.7) below the first sill may in part be atributed to well consolidated sediments, and to a change in lithology to more sandy sediments. This layer is interpreted to lie within the lower Cretaceous sequence. At 5-10 km depthV p /V s ratios of 1.85 indicate a lower sand/shale ratio consistent with the expected lithologies. The averageV p /V s ratio inferred for the crust is 1.75, which is consistent with values obtained north of Vøring, in the Lofoten area. An eastward thinning of the crystalline basement is supported by the shear-wave modelling. Birkhäuser Verlag, 1996 Vøring basin nationallicence 3C OBS data nationallicence shear waves nationallicence Digranes P. Institute of Solid Earth Physics, University of Bergen, Allegt. 41, 5007, Bergen, Norway aut Mjelde R. Institute of Solid Earth Physics, University of Bergen, Allegt. 41, 5007, Bergen, Norway aut Kodaira S. Laboratory for Ocean Bottom Seismology, Hokkaido University, 060, Sapporo, Japan aut Shimamura H. Laboratory for Ocean Bottom Seismology, Hokkaido University, 060, Sapporo, Japan aut Kanazawa T. Earthquake Research Institute, Tokyo University, Yayoi 1-1-1 Bunkyo-ku, 113, Tokyo, Japan aut Shiobara H. Earthquake Research Institute, Tokyo University, Yayoi 1-1-1 Bunkyo-ku, 113, Tokyo, Japan aut Berg E. Statoil R&D, Postuttak, 7004, Trondheim, Norway aut pure and applied geophysics Birkhäuser-Verlag 147/4(1996-10-01), 611-629 0033-4553 147:4<611 1996 147 24 https://doi.org/10.1007/BF01089694 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF01089694 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Digranes P. Institute of Solid Earth Physics, University of Bergen, Allegt. 41, 5007, Bergen, Norway aut NATIONALLICENCE 700 1- Mjelde R. Institute of Solid Earth Physics, University of Bergen, Allegt. 41, 5007, Bergen, Norway aut NATIONALLICENCE 700 1- Kodaira S. Laboratory for Ocean Bottom Seismology, Hokkaido University, 060, Sapporo, Japan aut NATIONALLICENCE 700 1- Shimamura H. Laboratory for Ocean Bottom Seismology, Hokkaido University, 060, Sapporo, Japan aut NATIONALLICENCE 700 1- Kanazawa T. Earthquake Research Institute, Tokyo University, Yayoi 1-1-1 Bunkyo-ku, 113, Tokyo, Japan aut NATIONALLICENCE 700 1- Shiobara H. Earthquake Research Institute, Tokyo University, Yayoi 1-1-1 Bunkyo-ku, 113, Tokyo, Japan aut NATIONALLICENCE 700 1- Berg E. Statoil R&D, Postuttak, 7004, Trondheim, Norway aut NATIONALLICENCE 773 0- pure and applied geophysics Birkhäuser-Verlag 147/4(1996-10-01), 611-629 0033-4553 147:4<611 1996 147 24 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer