Benthic Boundary Layer

The benthic boundary layer is the near-bed water layer where friction with the sea floor controls the flow, spanning the viscous sublayer at the bed up through the logarithmic layer where velocity rises with the log of height above bottom. Its thickness ranges from centimeters to tens of meters depending on current strength and stratification. The layer sets the bottom stress that mobilizes sediment, so it governs erosion, deposition, and bedform growth, and it hosts a turbid nepheloid layer of resuspended material. Friction velocity and bed roughness, derived from the log-law profile, are the parameters that link current speed to sediment transport.