Water masses and suspended matter circulation on the French Guiana continental shelf

This paper discusses the Amazonian solid and liquid fluxes along the coast of French Guiana. The seasonal hydrology and meteorology shows that suspended matter is locally limited to the zone of bank migration in a nepheloid layer. There is more turbidity on the bank as a result of resuspension of significant amounts of particles. The suspended load on the shelf is subject to the circulation of water masses: at the surface the Guiana Current and at the bottom tidal currents (inner shelf) and local counter current (outer shelf). The path of the currents emphasizes that the low amount of suspended matter observed offshore do not influence the build up of the mud prism, which is due to coastal transport. The energy flux and the volume of sediments transported in the banks has been calculated and the results are comparable to those obtained in Guiana and Suriname. However, variable coastal morphology induces differences in energy fluxes. As a result, some areas undergo both erosion and sedimentation.