River Ocean Interactions and Deltaic Systems

Rivers supply water, sediment and nutrients to the oceans, and they have done so over millions of years. Accumulations of these materials are where we find oil and gas to power our societies, and river deltas are some of the most fertile areas of the Earth and home for millions of people. The processes affecting river-ocean interaction are numerous and complex, including fluvial discharge, tidal flows, storm surges and wave conditions. Our lab group has studied these systems for decades, and research on various aspects will continue into the future. Example publications:

Walsh, J.P., Corbett, D.R., Ogston, A.S., Nittrouer, C., Kuehl, S.A., Allison, M.A., and S.L.
Goodbred Jr. 2013. Shelf and slope sedimentation associated with large deltaic systems.
Editors: T.S. Bianchi, M.A. Allison, and W. Cai, In: Biogeochemical Dynamics at Major
River-Coastal Interfaces: Linkages with Global Change. Cambridge University Press, New
York, NY, 704 pgs.

Walsh, J.P. and C.A. Nittrouer. 2009. Towards an Understanding of Fine-grained River
Sediment Dispersal on Continental Margins. Marine Geology, 263: 34-45.

Corbett, D.R., Dail, M.D, McKee, B.A., 2007. High frequency time-series of the dynamic
sedimentation processes on the western shelf of the Mississippi River delta. Continental
Shelf Research, 27, 1600-1615.

Walsh, J. P., C. R. Alexander, T. Gerber, A R. Orpin, and B. W. Sumners. 2007. Demise of a
submarine canyon? Evidence for highstand infilling on the Waipaoa River continental
margin, New Zealand, Geophysical Research Letters, 34: L20606, doi:10.1029/2007GL031142.

Dail, M.D., Corbett, D.R., Walsh, J.P., 2007. Assessing the Importance of a Major Hurricane on
Continental Margin Sedimentation in the Mississippi Delta Region. Continental Shelf
Research, 27, 1857-1874.

Example Research Project

Impacts of Hurricane Katrina (2005) on the Mississippi River Delta

In the wake of Hurricanes Katrina and Rita, the damage on land is dramatic. Few consider the impacts such events may have upon our oceans. CP researchers, Walsh and Corbett, evaluated the effects of Hurricane Katrina on the ocean floor in the Gulf region.

As part of a National Science Foundation grant, nine ECU Geology and Coastal Resources Management faculty members and students arrived in Louisiana two days after Hurricane Rita made landfall to study how the two hurricanes shifted sediments, nutrients and chemicals in the Mississippi and Atchafalaya deltas. The data has provided new insights into seabed disturbance that has important implications for geochemical and biological processes. Also, observations will help with future evaluations of where to place

On a 10 days research cruise, CSI and ECU scientist worked aboard the research vessel Cape Hatteras. The scientists demonstrated that major weather events like Hurricane Katrina have a disproportionate role in the destabilization and redistribution of sediments and chemicals in the coastal waters of Louisiana. The study focused on how sediments move within the deltaic system in short amounts of time. The movement and/or storage of sediments and nutrients – such as carbon and oxygen – along continental margins can have several effects on the environment, including the cycling of carbon dioxide between the ocean and atmosphere.

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Research team aboard the R/V Cape Hatteras. After a successful cruise in the Gulf of Mexico, the group prepares for departure.