HR: 16:00h
AN: NS14A-01    [Abstracts]
TI: The Potential for use of 3D-Seismic Data in Glacial Geological Studies With Examples From the Norwegian Shelf
AU: * Ottesen, D
EM: dag.ottesen@ngu.no
AF: Geological Survey of Norway, Leiv Eirikssons vei 39, Trondheim, 7041, Norway
AU: Rise, L
EM: leif.rise@ngu.no
AF: Geological Survey of Norway, Leiv Eirikssons vei 39, Trondheim, 7041, Norway
AU: Andersen, E
EM: espen.sletten.andersen@hydro.com
AF: Norsk Hydro ASA, Oslo, Oslo, 0246, Norway
AU: Dowdeswell, J
EM: jd16@cam.ac.uk
AF: Scott Polar Research Institute, University of Cambridge, Lensfield Road, Cambridge, CB2 1ER, United Kingdom
AB: The Norwegian shelf is probably the best investigated glaciated margin in the world. This is mainly due to an extensive exploration by the hydrocarbon industry, which has generated a huge data base comprising 2D and 3D seismic lines, detailed bathymetry, exploration wells and geotechnical borings. A large part of the Norwegian shelf is covered by 3D seismics, and these data have a great potential for use in glacial geological studies. The spacing between the seismic lines in 3D-seismic cubes is generally 12.5 m, and the vertical resolution is 4 ms (c. 3 m) providing excellent data coverage. All types of cross-sections and time-slices can be performed and visualised, giving a good overview of the whole seismic cube in three dimensions. The mapping of deeply buried surfaces several hundred metres below the present sea floor has given us evidence of glacial influence such as glacial lineations and iceberg ploughmarks far back in time. Late Tertiary uplift of Scandinavia and several tens of glaciations have denuded the inner shelf and corresponding land areas (the western part of the mountain range) an average of 450 m. The Naust Formation (< 2.8 million years) comprising all the glacial sediments of the mid-Norwegian shelf is more than 1000 m thick over large areas of the outer shelf. The large volume of the Naust Formation has raised the question of how these sediments were eroded and transported onto the shelf during such a short time. Mapping by 3D seismics has revealed glacial influence up to 2 million years back in time and has given some clues to these processes.
DE: 0726 Ice sheets
DE: 0730 Ice streams
DE: 3002 Continental shelf and slope processes (4219)
DE: 3025 Marine seismics (0935, 7294)
DE: 3094 Instruments and techniques
SC: Near-Surface Geophysics [NS]
MN: 2007 Fall Meeting