Suspended Particulate Matter Transport through the Vema Channel

Sixteen-month time-series measurements of water velocity and light scattering were coupled with hydrographic and suspended particulate matter sections to determine the flux and the variability in flux of suspended particulate matter through the Vema Channel. The northward flux of SPM through the Vema Channel ranged from 3 to 10.5 × 104 g s 1 with a mean of 6.5 × 104 g s 1. The largest fluxes were measured in the deepest and eastern portions of the channel with maximum fluxes of suspended particulate matter at specific sites being roughly two to four times the mean flux. Some of the suspended particulate matter in the channel may be eroded from the channel itself by the swift currents or eddy-like features, however, the known manganese encrustation and hard floor of the channel suggest that the deep channel floor is not a likely source of sediment. A primary source of the suspended particulate matter in the channel may be the sediment drifts in the Argentine Basin with their associated high standing crops of resuspended particulate matter. This resuspended material would then be transported by the Antarctic Bottom Water into and through the Vema Channel into the Brazil Basin. The northward flux of suspended particulate matter through the Vema Channel is presently a significant, but not dominant, influence on sedimentation in the Brazil Basin.