FN Archimer Export Format
PT J
TI The influence of bottom currents on the Zambezi Valley morphology (Mozambique Channel, SW Indian Ocean): In situ current observations and hydrodynamic modelling
BT 
AF MIRAMONTES, Elda
   Penven, Pierrick
   Fierens, Ruth
   Droz, Laurence
   Toucanne, Samuel
   Jorry, Stephan
   Jouet, Gwenael
   Pastor, Lucie
   SILVA JACINTO, Ricardo
   Gaillot, Arnaud
   Giraudeau, Jacques
   Raisson, François
AS 1:1;2:2;3:1;4:1;5:3;6:3;7:3;8:4;9:3;10:3;11:5;12:6;
FF 1:;2:;3:;4:;5:PDG-REM-GM-LGS;6:PDG-REM-GM-LGS;7:PDG-REM-GM-LGS;8:PDG-REM-EEP-LEP;9:PDG-REM-GM-LGS;10:PDG-REM-GM-CTDI;11:;12:;
C1 UMR 6538 CNRS-UBO, IUEM, Laboratoire Géosciences Océan, 29280 Plouzané, France
   UMR 6523 CNRS, IFREMER, IRD, UBO, Laboratoire d'Océanographie Physique et Spatiale, Plouzané 29280, France
   IFREMER, Géosciences Marines, Centre de Brest, 29280 Plouzané, France
   IFREMER, Laboratoire Environnement Profond, Centre de Brest, 29280 Plouzané, France
   EPOC, UMR 5805, Université de Bordeaux, CNRS, 33615, Pessac CEDEX, France
   TOTAL, R&D Frontier Exploration program, 64000 Pau, France
C2 CNRS, FRANCE
   IRD, FRANCE
   IFREMER, FRANCE
   IFREMER, FRANCE
   UNIV BORDEAUX, FRANCE
   TOTAL, FRANCE
SI BREST
SE PDG-REM-GM-LGS
   PDG-REM-EEP-LEP
   PDG-REM-GM-CTDI
UM LOPS
   LGO
IN WOS Ifremer UPR
   WOS Cotutelle UMR
   copubli-france
   copubli-p187
   copubli-univ-france
IF 3.04
TC 41
UR https://archimer.ifremer.fr/doc/00476/58743/61269.pdf
LA English
DT Article
CR GEBCO 2005 LEG 1
   GEBCO 2005 LEG 2
   GEBCO 2006 LEG 1
   GEBCO 2006 LEG 2
   PAMELA-MOZ01
   PAMELA-MOZ02
   PAMELA-MOZ04
   PAMELA-MOZ08
   PTOLEMEE
BO Beautemps-Beaupré
   L'Atalante
   Pourquoi pas ?
   Antea
DE ;Contourite;Turbidity current;Mixed system;Oceanic circulation;Mooring;ADCP;ROMS model;Bedform
AB Mixed turbidite-contourite systems can be found in oceans where bottom currents and turbidity currents interact. The Zambezi turbidite system, located in the Mozambique Channel (SW Indian Ocean), is one of the largest sedimentary systems in the world in length and area of the related catchments. The oceanic circulation in the Mozambique Channel is intense and complex, dominated by eddies flowing southwards and deep currents flowing northwards along the Mozambican margin. Current measurements obtained from moorings at 3400–4050 m water depth in the Zambezi and Tsiribihina valleys show periods of intense currents at the seafloor with peaks of 40–50 cm s−1 that last up to one month and are not related to turbidity currents. These strong bottom-current events are correlated with a change in current direction and an increase in temperature. The periods of current intensification may be related to eddies, since they present similar frequencies (around 7 per year). Moreover, modelling results show that during periods of intense deep circulation an anticyclonic eddy is present between the Mozambican slope and the centre of the Mozambique Channel, which may block the northward transport of the deep water mass and thus enhance the southward transport along the western slope of Madagascar. According to our hydrodynamic modelling of the circulation near the seafloor, intense currents are often present along the Zambezi Valley, especially along the valley flanks. Multi-channel seismic reflection data show that the Zambezi turbidite system does not show the typical characteristics of turbidite systems, being dominated by erosional processes, which mainly affect the valley flanks. Levees associated with the valley are absent in the main axis of the system. The effect of bottom currents on sedimentation in the basin is evidenced by the low sedimentation rates that witness winnowing in the basin, the presence of contouritic sand in the Zambezi Valley flanks and the abundance of current-related bedforms observed in multibeam bathymetry and seismic data. The intense oceanic processes observed in the Mozambique Channel may transport a large part of the fine sediment out of the basin and erode the seafloor even at great depths. Therefore, the Zambezi turbidite system could at present be considered as a mixed turbidite-contourite system, with important implications for source-to-sink studies. 
PY 2019
PD APR
SO Marine Geology
SN 0025-3227
PU Elsevier BV
VL 410
UT 000460716000005
BP 42
EP 55
DI 10.1016/j.margeo.2019.01.002
ID 58743
ER

EF