Regarding the Bottom Nepheloid Layer in the Kane Gap

The first evidence of the existence of a bottom nepheloid layer in the Kane Gap (Central East Atlantic) was obtained from acoustic backscattering data. It was located within the transformed Antarctic Bottom Water and was 150 m thick. The high velocities of bottom currents in the Gap suggest the permanence of the bottom nepheloid layer. The detailed structure of the vertical distribution of Antarctic Bottom Water tracers – oxygen and mineral silicate– has been revealed. Large biomineral aggregates (~40 μm) were found in the bottom suspended matter of the Kane Gap. They form in the highly productive North African upwelling area and are rapidly deposited to the ocean bottom layer due to ballasting of gel-like phytoplankton products by dense mineral particles from the Sahara Desert. Surface and bottom currents carry the suspended sediment aggregates to Kane Gap.