Detailed Structure of Buried Glacial Landforms Revealed by High-resolution 3D Seismic Data in the SW Barents Sea
B. Bellwald, S. Planke, S. Polteau, N. Lebedeva-Ivanova, A. Hafeez, J.I. Faleide and R. Myklebust
Event name: 80th EAGE Conference and Exhibition 2018
Session: Near Surface - Shallow Marine Geophysics
Publication date: 11 June 2018
Info: Extended abstract, PDF ( 778.44Kb )
Price: € 20
Glacial landforms identified in seismic 3D and multibeam data of the Barents Sea have improved the knowledge about past glaciations and associated geohazards. High-resolution P-Cable 3D seismic data were acquired in this area with an inline separation of 6 m, a source frequency range of 5-350 Hz and an source-receiver offset range of 120-160 m. Seabed images derived from the P-Cable data show an increased resolution and sharpness compared to images from conventional 3D seismic and multibeam echosounder data. High-resolution images of the buried Upper Regional Unconformity (URU) were derived from the P-Cable data, revealing previously unrecognized structures such as hill-hole pairs and rhombohedral and transverse ridges. These observations indicate different subglacial thermal regimes, the presence of permafrost, and a strong link with variations in the underlying geology. No reflections are imaged within the intraglacial sediment package in the conventional seismic data. However, reflections interpreted as the top of a shear margin moraine, shear planes, mass transport deposits, and soft beds are visible in the P-Cable data. Meter-scale glacial landforms and layers identified in the P-Cable cubes comprise new information about glacier dynamics, fluid flow, and faults, which are valuable for geotechnical and geohazard evaluations of offshore infrastructure.