HR: 0800h
AN: T41E-1259    [Abstracts]
TI: DHOFAR Seismic Experiment: First results to understand the breakup processes in a passive margin context
AU: * tiberi, c
EM: christel.tiberi@lgs.jussieu.fr
AF: Laboratoire de tectonique CNRS UMR7072 UPMC, 4 place jussieu, Paris cedex 05, 75252 France
AU: Leroy, S
EM: sylvie.leroy@lgs.jussieu.fr
AF: Laboratoire de tectonique CNRS UMR7072 UPMC, 4 place jussieu, Paris cedex 05, 75252 France
AU: d'Acremont, E
EM: dacremont@obs-vlfr.fr
AF: Laboratoire de tectonique CNRS UMR7072 UPMC, 4 place jussieu, Paris cedex 05, 75252 France
AU: Pointu, A
EM: agnes.pointu@lgs.jussieu.fr
AF: Laboratoire de tectonique CNRS UMR7072 UPMC, 4 place jussieu, Paris cedex 05, 75252 France
AU: Ebinger, C
EM: c.ebinger@gl.rhul.ac.uk
AF: Royal Holloway University of London, geology Dept., Queen's building, Egham, TW20 0EX United Kingdom
AU: Brisbourne, A
EM: amb27@leicester.ac.uk
AF: SEIS-UK, University of Leicester University road, Leicester, LE1 7RH United Kingdom
AU: Denton, P
EM: pdt@leicester.ac.uk
AF: SEIS-UK, University of Leicester University road, Leicester, LE1 7RH United Kingdom
AU: Al-Lazki, A
EM: lazki@squ.edu.om
AF: Earthquake Monitoring Center, SQU, P.O. Box 36, Muscat, 123 Oman
AU: Al-Azri, H
EM: dgml@mocioman.gov.om
AF: Directorate of minerals, P.O. Box 550, Muscat, 113 Oman
AU: Bin Monshir Bahlaf, S
EM: saeedmon88@hotmail.com
AF: Directorate of minerals, P.O. Box 550, Muscat, 113 Oman
AU: Brunet, C
EM: christophe.brunet@lgs.jussieu.fr
AF: Laboratoire de tectonique CNRS UMR7072 UPMC, 4 place jussieu, Paris cedex 05, 75252 France
AU: Famin, V
EM: vincent.famin@lgs.jussieu.fr
AF: Laboratoire de tectonique CNRS UMR7072 UPMC, 4 place jussieu, Paris cedex 05, 75252 France
AU: Labrousse, L
EM: loic.labrousse@lgs.jussieu.fr
AF: Laboratoire de tectonique CNRS UMR7072 UPMC, 4 place jussieu, Paris cedex 05, 75252 France
AB: The process of strain localisation preceding the onset of seafloor spreading is still poorly understood, though extensively studied. The reason is the differences in lithospheric properties, proximity to hot spot(s) and melt generation and extraction that lead to a variety of structural styles with major differences. The eastern Gulf of Aden represents a natural laboratory to study passive continental margins for many reasons: post-rift sedimentary strata are relatively thin, both onshore and nearshore structures are well-exposed, and conjugate margins can be precisely reconstructed. A first cruise (ENCENS-SHEBA), in 2000, has established the structural and geophysical framework using bathymetric swath mapping and underway geophysics. Later on, the Dhofar seismic experiment consisted in the deployment of a network of 11 broadband seismic stations from March 2003 to March 2004 on the northern margin, in the Dhofar area, southern Oman. This experiment was dedicated to the detailed study of the crust and upper mantle beneath the northern passive margin. CMG40TD 3-components seismometers from SEIS-UK network were used. We have recorded hundreds of teleseismic events with a good azimuthal coverage. Three main studies are then attempted. First, a teleseismic image of the first 200 km depth will be established using the P- and PKP-phases. This will allow a 3D representation of crustal and upper mantle velocity structures. We present here the preliminary results from the study of the traveltime residuals. The image resolution shall be enhanced by combining gravity data. Second, a receiver function analysis will locally determine the depth of the main interfaces (eg, Moho boundary). Finally, events recorded within the 1000-6000 km distance range will improve the regional S-wave velocity structure in this area and will help to locate the main regional wide structures related to this extended area.
DE: 7294 Instruments and techniques
DE: 8105 Continental margins and sedimentary basins
DE: 8122 Dynamics, gravity and tectonics
DE: 7203 Body wave propagation
DE: 7218 Lithosphere and upper mantle
SC: Tectonophysics [T]
MN: 2004 AGU Fall Meeting