HR: 1340h
AN: OS33B-0590    [Abstracts]
TI: Multi-Scale Analysis of Morphological Parameters on the Modern Congo Deep-Sea Channel
AU: * Turakiewicz, G
EM: tuka@dstu.univ-montp2.fr
AF: UMR 5573 - DL - Equipe Bassins, Univ. de Montpellier 2, CC 60 Place EugŠne Bataillon, Montpellier, 34095 France
AU: Lopez, M
EM: lopez@dstu.univ-montp2.fr
AF: UMR 5573 - DL - Equipe Bassins, Univ. de Montpellier 2, CC 60 Place EugŠne Bataillon, Montpellier, 34095 France
AU: Lucazeau, F
EM: lucazeau@ipgp.jussieu.fr
AF: UMR 7097 - IPGP - G‚osciences Marines, 4, Place Jussieu, Paris, 75252 France
AU: Gaillot, P
EM: philippe.gaillot@univ-pau.fr
AF: FRE 2639 Imagerie G‚ophysique, UPPA, Avenue de l'Universit‚, Pau, 64013 France
AU: Gerard, J
EM: Jean.gerard@total.com
AF: Total - EP - I.S.S. Clas, C.S.T.J.F. - Avenue LARRIBAU, Pau, 64018 France
AB: The overreaching motivation for this study is to improve understanding of underwater sedimentological processes that govern construction and organisation of siliciclastic deposits on abyssal plains. These processes have been poorly constrained so far, due to a lack of modern high-resolution bathymetric, seismic, and lithological data. Recent advances in the resolution of subsurface imagery now reveal the existence of large river-fed submarine fans which reach 10 km in thickness and extend more than 1000 km in length (e.g. Amazon, Mississippi, Indus, Congo systems). These huge sedimentary units result from the development of highly meandering channel-levee systems that spread out across the seafloor. Relationships between the different morphological parameters extracted from bathymetric data also improved the channel-levee growth models. In Congo basin, multibeam bathymetry and high resolution 2D seismic acquired during the ZAIANGO project (Total - Ifremer cooperation) have covered almost the entire fan surface, from the shelf to the deep basin and have provided better constraints on the fan architecture and morphology. Using multi-scale wavelet analysis, we show that the morphological parameters (levees and channel width and depth, longitudinal channel profile .) clearly record the successive phases of channel development and bifurcation. Hydrodynamic-related parameters (wavelength, sinuosity, gradient, width and depth of channel) reveal a periodic evolution linked to the dynamic of turbidity currents. Recurrent changes in the channel slope (wavelength = 200 km) are interpreted as the result of periodic variations of the stream power along channel.
DE: 9800 GENERAL OR MISCELLANEOUS
SC: Ocean Sciences [OS]
MN: 2004 AGU Fall Meeting