Fluid seepage in relation to seabed deformation on the central Nile Deep-Sea Fan, part 2: evidence from multibeam and sidescan imagery
| Type | Article | ||||||||||||
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| Date | 2014 | ||||||||||||
| Language | English | ||||||||||||
| Other localization | http://link.springer.com/chapter/10.1007/978-3-319-00972-8_13# | ||||||||||||
| Author(s) | Praeg Daniel1, Ketzer Joao Marcelo2, Augustin Adolfo Herbert2, Migeon Sebastien3, Ceramicola Silvia1, Dano Alexandre3, Ducassou Emmanuelle5, Dupre Stephanie 6, Mascle Jean4, Rodrigues Luiz Frederico2 |
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| Affiliation(s) | 1 : OGS (Istituto Nazionale di Oceanografia e di Geofisica Sperimentale), Borgo Grotta Gigante 42c, 34010, Trieste, Italy 2 : 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 3 : Géoazur, UMR7329, UNS-UPMC-CNRS-OCA, Rue Albert Einstein, 06560, Valbonne, France 4 : Université Bordeaux 1, UMR5805 EPOC, Avenue des facultés, 33405, Talence, France 5 : IFREMER, Technopôle Brest-Iroise, 29280, Plouzané, France 6 : Géoazur, UMR7329, UNS-UPMC-CNRS-OCA, Porte de la Darse, Villefranche-sur-Mer, France |
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| Source | Advances in Natural and Technological Hazards Research (1878-9897) (Springer Int Publishing Ag), 2014 , Vol. 37 , P. 141-150 | ||||||||||||
| DOI | 10.1007/978-3-319-00972-8_13 | ||||||||||||
| WOS© Times Cited | 8 | ||||||||||||
| 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. 2014. ISBN: 978-3-319-00971-1 (Print) 978-3-319-00972-8 (Online) | ||||||||||||
| Keyword(s) | Slope undulations, Fluid seeps, Backscatter, Carbonates, Pipes, Faults | ||||||||||||
| Abstract | On the central Nile deep-sea fan, stratified sediments overlying mass-transport deposits (MTDs) are deformed into slope-parallel seabed undulations associated with fluid seepage. The western part of this system, in water depths of 1,950–2,250 m, is examined using multi-frequency data from hull-mounted and deep-towed swath/profiling systems. Sub-bottom profiles show sub-vertical fluid pipes that terminate both at and below seabed, and gas signatures along fault planes bounding the undulations. Fluid seepage is recorded by high- to intermediate-backscatter patches (HBPs, IBPs) that differ in appearance on multibeam imagery (30 kHz, ≤3 m penetration) and sidescan swaths (170/190 kHz, <0.1 m penetration). Comparison of the two suggests a distinction of (a) buried carbonates (0.1–3 m), (b) broad near-seabed (<0.1 m) carbonate pavements elongate along the undulations, (c) sub-circular areas of seabed seepage up to 300 m across. Four of the latter have narrower gas flares at their edges rising 400–800 m above seabed. These results are consistent with an evolving system of narrow fluid conduits that support the growth and burial of carbonate pavements, shifting over millennial timescales along linear zones parallel to fault planes rooted in MTDs. Sediment deformation above MTDs is inferred to provide pathways for fluid escape, but migration of gas-rich fluids from depth is likely to have facilitated slope destabilisation. | ||||||||||||
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