Scaling response of a canyon-incised shelf break

Abstract

[Author's Abstract] The continental shelf break is a global, large-scale geologic structure which separates continents from the deep sea. Along the shelf break many finer-scale features can be recognized, such as canyons and slope faces. As depth measurements are represented more frequently in space (finer resolution), and as the area of observation becomes smaller (smaller extent), even finer-scaled features of the seafloor are exposed. At the finest scales of observation, small universal variations such as fine ridges and valleys create a rough seafloor that is indistinguishable from seafloor elsewhere in the ocean. Using multibeam sonar data of the continental shelf break off the southwest coast of Baja, Mexico, I compared seafloor roughness between a canyon and slope face at different resolutions and distances from the line which separates the shelf and slope. Regions above the canyon and slope face were found to be very similar at all resolutions, while roughness within the canyon varied from that of the slope face. The inherent difference between the canyon and slope face was best observed at a 20-40 meter resolution at distances greater than 250 meters. As well as giving insight into structures which define the shelf break, results of this study can act as a guide for designing future studies on the continental shelf break.