FN Archimer Export Format
PT J
TI The influence of Congo River discharges in the surface and deep layers of the Gulf of Guinea
BT 
AF VANGRIESHEIM, Annick
   PIERRE, C
   AMINOT, Alain
   METZL, N
   BAURAND, F
   CAPRAIS, Jean-Claude
AS 1:1;2:2;3:1;4:2;5:3;6:1;
FF 1:PDG-DOP-DCB-EEP-LEP;2:;3:PDG-DOP-DCB-DYNECO-PELAGOS;4:;5:;6:PDG-DOP-DCB-EEP-LEP;
C1 IFREMER, DEEP LEP, F-29280 Plouzane, France.
   Univ Paris 06, LOCEAN, F-75252 Paris 05, France.
   Ctr IRD Bretagne, F-29280 Plouzane, France.
C2 IFREMER, FRANCE
   UNIV PARIS 06, FRANCE
   IRD, FRANCE
SI BREST
SE PDG-DOP-DCB-EEP-LEP
   PDG-DOP-DCB-DYNECO-PELAGOS
IN WOS Ifremer jusqu'en 2018
   copubli-france
   copubli-p187
   copubli-univ-france
IF 1.965
TC 29
TU Centre national de la recherche scientifique
   Institut de recherche pour le développement
   Muséum national d'histoire naturelle
   Université Pierre et Marie Curie
UR https://archimer.ifremer.fr/doc/2009/publication-6737.pdf
LA English
DT Article
CR BIOZAIRE 1
   BIOZAIRE 2
   BIOZAIRE 3
   BIOZRECUP
   BIOZRECUP2
BO Unknown
   Anchored Buoy
   Beautemps-Beaupré
DE ;DIC;Stable isotopes;Nutrient anomaly;Oxygen anomaly;Congo canyon;Gulf of Guinea
AB The main feature of the Congo-Angola margin in the Gulf of Guinea is the Congo (ex-Zaire) deep-sea fan composed of a submarine canyon directly connected to the Congo River, a channel and a [sediment] lobe area. During the multi-disciplinary programme called BIOZAIRE conducted by Ifremer from 2000 to 2005, two CTD-O2 sections with discrete water column samples were performed (BIOZAIRE3 cruise: 2003-2004) to study the influence of the Congo River discharges, both in the surface layer and in the deep and near-bottom layers. The surface layer water is greatly diluted with river water that has a heavy particle load. The deep layer is affected by episodic turbidity currents that flow in the deep Congo channel and reach deep areas far from the coast. Previous studies revealed deep anomalies in oxygen (deficit) and nutrient (excess) concentrations at not, vert, similar4000 m depth and assumed that they resulted from mineralisation of the particulate organic matter from the Congo River. The BIOZAIRE3 sections were designed to explore these phenomena in more detail near the Congo channel. Oxygen and nutrients were measured as well as additional parameters, including stable isotopes of oxygen and carbon, dissolved inorganic carbon and pH. For the surface layer, the effect of the Congo River was studied with reference to salinity. Deviations from the theoretical dilution of various inorganic solutes suggested the occurrence of mineralisation and consumption processes. For the deep layer, the network of CTD-O2 stations gave a more detailed description of the deep anomalies than in previous studies. From the east-west section, anomalies appeared on the bottom at 4000 m depth and became slightly shallower when they spread to the west. They were also present north and south on the bottom along the 4000 m isobath. In these deep waters, the decrease in the o13C values of dissolved inorganic carbon confirmed that the mineralisation of organic matter plays a role in generating these anomalies. The location of the origin of this deep anomaly is debated. Here, arguments are given in favour of mineralisation of the particulate organic matter input that overflows from the Congo channel at not, vert, similar4000 m depth during turbidity current events. Other authors suggest that this input comes from downslope particle transport. Anomalies of the same origin, but weaker, also occurred deeper on the Congo lobe, where the Congo channel ends, but with a significant pH decrease on the bottom which was not seen at 4000 m depth.
PY 2009
PD NOV
SO Deep Sea Research Part II: Topical Studies in Oceanography
SN 0967-0645
PU Elsevier
VL 56
IS 23
UT 000272366000004
BP 2183
EP 2196
DI 10.1016/j.dsr2.2009.04.002
ID 6737
ER

EF