Fine Sediment Dynamics
Analyzed storm-driven dispersal of fluvial fine sediment on a low-energy inner shelf and its influence on an offshore sand shoal, using in-situ measurements and satellite imagery.
The Challenge
The Louisiana coast is a low-energy, microtidal shelf whose sediment is predominantly fine (silt/clay) due to influx from the Mississippi and Atchafalaya rivers. It was unclear why and how this fine sediment persists on an otherwise sandy shoal, how its dynamics differ from sand, and whether it would affect future sand-mining operations there.
The Approach
Analyzed prolonged in-situ measurements and satellite imagery across winter storms and tropical cyclones to characterize storm-driven sediment resuspension and offshore advection pathways.
The Result
Published in Regional Studies in Marine Science (Kobashi & Jose, 2019) — found storm-driven advection transports resuspended fine sediment from the bay to the inner shelf and shoal regardless of storm type, with the dispersal mechanism varying by storm type, intensity, and track.
Thumbnail: Sediment in the Gulf of Mexico, MODIS/Aqua — public domain (NASA Earth Observatory, Norman Kuring/MODIS Ocean Team).