Characteristics of ocean bottom roughness for several seamounts derived from multibeam bathymetric data

Multibeam bathymetric systems offer to revolutionize our understanding of the ocean bottom and its major structural features by providing highly detailed measurements of the bottom. Further, multibeam measurements yield bottom depth as a function of both spatial coordinates (i.e. along-track and across-track). The depth resolution is sufficiently fine that conventional contour charts would never incorporate all the information available in the multibeam data. As an alternative to such deterministic presentations, it can be suggested that statistical characterizations be developed for topographic variability at horizontal scales which are small in comparison to the overall dimensions of the feature of interest. We here discuss the study of rough topography on several seamounts by means of multibeam bathymetry. The bottom topography is analyzed in terms of numerous samples of1600 m \times 1600m extent. A primary quantity of interest is the rms value of the residual topography. The pattern of variability for the rms values is described for several seamounts and shown to have certain overall similarities.