FN Archimer Export Format PT J TI Fluid seepage in relation to seabed deformation on the central Nile Deep-Sea Fan, part 2: evidence from multibeam and sidescan imagery BT AF PRAEG, Daniel KETZER, Joao Marcelo AUGUSTIN, Adolfo Herbert MIGEON, SEBASTIEN CERAMICOLA, Silvia DANO, Alexandre DUCASSOU, Emmanuelle DUPRE, Stephanie MASCLE, Jean RODRIGUES, Luiz Frederico AS 1:1;2:2;3:2;4:3;5:1;6:3;7:5;8:6;9:4;10:2; FF 1:;2:;3:;4:;5:;6:;7:;8:PDG-REM-GM-LGG;9:;10:; C1 OGS (Istituto Nazionale di Oceanografia e di Geofisica Sperimentale), Borgo Grotta Gigante 42c, 34010, Trieste, Italy 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 Géoazur, UMR7329, UNS-UPMC-CNRS-OCA, Rue Albert Einstein, 06560, Valbonne, France Université Bordeaux 1, UMR5805 EPOC, Avenue des facultés, 33405, Talence, France IFREMER, Technopôle Brest-Iroise, 29280, Plouzané, France Géoazur, UMR7329, UNS-UPMC-CNRS-OCA, Porte de la Darse, Villefranche-sur-Mer, France C2 OGS, ITALY CEPAC, BRAZIL UNIV NICE, FRANCE UNIV BORDEAUX, FRANCE IFREMER, FRANCE UNIV NICE, FRANCE SI AUTRE BREST SE AUTRE PDG-REM-GM-LGG IN WOS Ifremer jusqu'en 2018 copubli-france copubli-europe copubli-univ-france copubli-int-hors-europe copubli-sud TC 8 UR https://archimer.ifremer.fr/doc/00158/26956/25251.pdf LA English DT Article CR APINIL APINIL LEG1 APINIL LEG2 APINIL LEG3 BO Le Suroît DE ;Slope undulations;Fluid seeps;Backscatter;Carbonates;Pipes;Faults AB 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. PY 2014 SO Advances in Natural and Technological Hazards Research SN 1878-9897 PU Springer Int Publishing Ag VL 37 UT 000339716900013 BP 141 EP 150 DI 10.1007/978-3-319-00972-8_13 ID 26956 ER EF