Fluid Seepage in Relation to Seabed Deformation on the Central Nile Deep-Sea Fan, Part 1: Evidence from Sidescan Sonar Data

Type Article
Date 2014
Language English
Author(s) Dano Alexandre1, Praeg Daniel2, Migeon Sebastien1, Augustin Jean-Marie3, Ceramicola Silvia2, Ketzer Joao Marcelo4, Augustin Adolfo Herbert4, Ducassou Emmanuelle5, Mascle Jean6
Affiliation(s) 1 : Géoazur, UMR7329, UNS-UPMC-CNRS-OCA, Rue Albert Einstein, 06560, Valbonne, France
2 : OGS (Istituto Nazionale di Oceanografia e di Geofisica Sperimentale), Borgo Grotta Gigante 42c, 34010, Trieste, Italy
3 : IFREMER, Technopôle Brest-Iroise, Plouzané, France
4 : Center of Excellence in Research and Innovation in Petroleum, Mineral Resources and Carbon Storage (CEPAC), Pontifical University of Rio Grande do Sul (PUCRS), Av. Ipiranga 6681, Prédio 96J, CEP 90619-900, Porto Alegre, RS, Brazil
5 : Université Bordeaux 1, UMR5805 EPOC, Avenue des facultés, 33405, Talence, France
6 : Géoazur, UMR7329, UNS-UPMC-CNRS-OCA, Porte de la Darse, Villefranche-sur-Mer, France
Meeting 6th International Symposium on Submarine Mass Movements and Their Consequences, Kiel, GERMANY, SEP, 2013
Source Advances in Natural and Technological Hazards Research (1878-9897) (Springer Int Publishing Ag), 2014 , Vol. 37 , P. 129-139
DOI 10.1007/978-3-319-00972-8_12
WOS© Times Cited 2
Note In : Submarine Mass Movements and Their Consequences. 6th International Symposium Editors: Sebastian Krastel, Jan-Hinrich Behrmann, David Völker, Michael Stipp, Christian Berndt, Roger Urgeles, Jason Chaytor, Katrin Huhn, Michael Strasser, Carl Bonnevie Harbitz. Vol.37. Chapitre 12. 2014 ISBN: 978-3-319-00971-1 (Print) 978-3-319-00972-8 (Online)
Keyword(s) Fluid seepage, Sediment deformation, Backscatter, Gas flares
Abstract The central Nile Deep-Sea Fan contains a broad area of seabed destabilisation in association with fluid seepage: slope-parallel sediment undulations are associated with multibeam high-backscatter patches (HBPs) related to authigenic carbonates. During the 2011 APINIL campaign, a deep-towed sidescan and profiling system (SAR) was used to acquire high-resolution data along three transects across water depths of 1,700-2,650 m. Three seabed domains are distinguished, all developed within stratified sediments overlying mass-transport deposits (MTDs). Upslope of the undulations (<1,950 m), sidescan HBPs record focused fluid seepage via seabed cracks. In the western area of undulations, sidescan HBPs are distinct from intermediate-backscatter patches (IBPs) that extend up to 850 m parallel to the undulations, mainly along their downslope flanks; some contain sub-circular HBPs up to 300 m wide, three associated with smaller (<10 m) hydroacoustic gas flares. Focused fluid seeps are inferred to have shifted over time to form elongate carbonate pavements, preferentially along the footwalls of faults beneath the undulations that provide pathways for fluid flow. In contrast, in the eastern area of undulations, sidescan imagery reveal only slope-transverse furrows formed by turbulent flows, interpreted to indicate that fossil carbonates sampled during submersible operations have been exhumed by erosion.
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Dano Alexandre, Praeg Daniel, Migeon Sebastien, Augustin Jean-Marie, Ceramicola Silvia, Ketzer Joao Marcelo, Augustin Adolfo Herbert, Ducassou Emmanuelle, Mascle Jean (2014). Fluid Seepage in Relation to Seabed Deformation on the Central Nile Deep-Sea Fan, Part 1: Evidence from Sidescan Sonar Data. Advances in Natural and Technological Hazards Research, 37, 129-139. Publisher's official version : https://doi.org/10.1007/978-3-319-00972-8_12 , Open Access version : https://archimer.ifremer.fr/doc/00226/33752/