Effects of marine channel morphology on sediment depositional characteristics

Abstract

[Author's Abstract] Understanding how the shape of marine channels controls the patter of sediment deposited within them can help explain the relationship between seafloor channels and terrestrial rivers. Also, marine channels carry carbon and nitrogen, as well as other nutrients and pollutants, from the land to the deep ocean and are very important for understanding earth's chemical and physical cycles. This study used a seafloor sonar survey in combination with three sediment cores taken off the tip of the Baja Peninsula. The bathymetry from the survey was analyzed to determine how much each channel meandered (sinuosity), how steep the bottom of each channel was (slope), and how much area in the channel was available for flow. Cores were analyzed to determine the size of particles and how fast they are deposited within each channel. Differences in these characteristics were compared across the three channels studied. Sinuosity appears to be the direct control on sediment characteristics, and slope does not appear to have any effect.