Dynamic processes of the benthic boundary layer in the subaqueous yellow river delta, China

Abstract

The benthic, or bottom, boundary layer (BBL) is the region of the ocean adjacent to the ocean floor. The complex dynamic process of the BBL is closely related to seabed stability and geological hazards. In this study, the subaqueous Yellow River delta, where submarine landslide and erosion occur frequently, was chosen to conduct in situ observations. Hydrodynamic data, including wave and current parameters, and seawater turbidity, was observed using a tripod observation system. Besides, the excess pore water pressure was observed simultaneously below the seabed surface at depths of 30 and 60 cm. Data analysis showed that wave-induced shear stress can lead to the slight seabed erosion, while waveinduced pore water accumulation inside the seabed can greatly contribute to the severe seabed erosion.