HR: 0830h
AN: OS51C-0866    [PDF]
TI: A High-Resolution Deep-Towed Seismic Survey in the Mound Region Along the Continental Slope off Nicaragua
AU: * Breitzke, M
EM: mbreitzke@geomar.de
AF: GEOMAR Research Centre for Marine Geosciences, Wischhofstrasse 1 - 3, Kiel, D-24148 Germany
AU: * Breitzke, M
EM: mbreitzke@geomar.de
AF: SFB-574, Wischhofstrasse 1 - 3, Kiel, D-24148 Germany
AU: Bialas, J
AF: GEOMAR Research Centre for Marine Geosciences, Wischhofstrasse 1 - 3, Kiel, D-24148 Germany
AU: Bialas, J
AF: SFB-574, Wischhofstrasse 1 - 3, Kiel, D-24148 Germany
AU: Buerk, D
AF: SFB-574, Wischhofstrasse 1 - 3, Kiel, D-24148 Germany
AU: Fekete, N
AF: SFB-574, Wischhofstrasse 1 - 3, Kiel, D-24148 Germany
AU: Flueh, E
AF: GEOMAR Research Centre for Marine Geosciences, Wischhofstrasse 1 - 3, Kiel, D-24148 Germany
AU: Flueh, E
AF: SFB-574, Wischhofstrasse 1 - 3, Kiel, D-24148 Germany
AU: Klaeschen, D
AF: GEOMAR Research Centre for Marine Geosciences, Wischhofstrasse 1 - 3, Kiel, D-24148 Germany
AU: Klaeschen, D
AF: SFB-574, Wischhofstrasse 1 - 3, Kiel, D-24148 Germany
AU: Klaucke, I
AF: SFB-574, Wischhofstrasse 1 - 3, Kiel, D-24148 Germany
AU: Papenberg, C
AF: GEOMAR Research Centre for Marine Geosciences, Wischhofstrasse 1 - 3, Kiel, D-24148 Germany
AU: Ranero, C
AF: GEOMAR Research Centre for Marine Geosciences, Wischhofstrasse 1 - 3, Kiel, D-24148 Germany
AU: Ranero, C
AF: SFB-574, Wischhofstrasse 1 - 3, Kiel, D-24148 Germany
AU: SO173-1 Working Group, .
AF: GEOMAR Research Centre for Marine Geosciences, Wischhofstrasse 1 - 3, Kiel, D-24148 Germany
AU: SO173-1 Working Group, .
AF: SFB-574, Wischhofstrasse 1 - 3, Kiel, D-24148 Germany
AB: In July 2003 RV SONNE conducted the SUBDUCTION II cruise SO173-1 offshore Costa Rica and Nicaragua. During this cruise the GEOMAR deep-towed multichannel seismic streamer was used along several profiles to study mound structures and fluid escape features at the continental margin of Middle America. Besides revisiting locations off Costa Rica a new survey area was investigated offshore Nicaragua. According to earlier recorded multibeam bathymetry several mound structures of unknown size were expected within this area. A set of 13 parallel profiles covered an area of approximately 700 km$^{2}$ in water depths between 1000 m and 2300 m. Both bathymetry and seismic lines showed that the continental margin off Nicaragua is dominated by deeply incised canyons and numerous mound structures as well as slides at the lower slope. The two most prominent mounds "Nica-1" and "Nica-2" are located at the uppermost continental slope. The larger one rises about 300 m above the surrounding sea floor. Well stratified sedimentary layers of about 250 - 300 m thickness in the deep towed seismic sections are based by a band of strong reflections throughout the entire area. They seem to form the recent base for the deeply incised canyons, which at some locations have stopped some meters above and at other locations have cut into this high reflectivity band, but none of them cut through this reflection band. Underneath occurs a less reflective zone in which a BSR is visible in most parts of the survey area. This BSR varies in strength along the profile lines and appears to be discontinuous in parts. Preliminary single-fold seismogram sections additionally indicate local interruptions of the BSR underneath mound structures. Further data will proof if the BSR can be followed underneath the mounds. An overview of the data and first results will be presented.
UR: http://www.geomar.de
DE: 0930 Oceanic structures
DE: 0935 Seismic methods (3025)
DE: 3022 Marine sediments--processes and transport
DE: 3025 Marine seismics (0935)
DE: 3094 Instruments and techniques
SC: Ocean Sciences [OS]
MN: 2003 Fall Meeting