Bedform-velocity matrix: The estimation of bottom current velocity from bedform observations

Abstract

A wide variety of bedforms, both depositional and erosional in origin, has been recognized on the deep seafloor and attributed to the influence of bottom currents. These range in scale from those visible in bottom photographs (centimeter to decimeter), to those recorded with seafloor bathymetric imaging (meter to kilometer). In many cases it has been possible to provide some quaication of substrate grain size and flow velocity responsible for each bedform type. We have synthesized both our own and published data in order to present a bedform-velocity matrix, which facilitates the estimation of bottom current velocity based on bedform type. Despite imperfections, we believe this to be a valuable model for assessing strength and variability of bottom currents that can have a significant influence on the siting of submarine cables, pipelines, and other seafloor installations.