Abstract

Over the past few years, studies on the cycling of organic matter in river dominated ocean margins have revealed novel results that challenge established views regarding the importance of land-derived organic carbon in these environments. The goal of this talk is to present case studies that highlight new insights on what factors control the fluxes and fates of terrigenous organic carbon in the ocean margins. Particular emphasis will be given to the nature/composition of the organic matter exported by rivers and the effect it has in the ultimate fate of the material once it enters the ocean. In addition, I will focus part of the talk on the role that particle dispersion processes play in the transformations of terrigenous (and marine) organic matter prior to its sequestration in margin sediments.

Some recent papers my group has published on the subject:

Goņi M. A., Yunker, M. B., Macdonald, R. W., and Eglinton, T. I. (2005) The supply and preservation of ancient and modern components of organic carbon in the Canadian Beaufort Shelf of the Arctic Ocean . Marine Chemistry 93, 53-73.

Gordon E. S. and Goņi M. A. (2004) Controls on the distribution and accumulation of terrigenous organic matter in sediments from the Mississippi and Atchafalaya River Margin. Marine Chemistry 92 , 331- 35 2.

Goņi M. A., Teixeira M. J., Perkey D. W. (2003) Sources and distribution of organic matter in a river-dominated estuary ( Winyah Bay , South Carolina , USA ). Estuarine, Coastal and Shelf Sciences 57, 1023-1048.

Torres R., Mwamba M. J., and Goņi M. A. (2003) Properties of intertidal marsh sediment mobilized by rainfall. Limnology and Oceanography48, 1245-1253.

Biographical Sketch

Miguel Goni received his Ph.D. in Chemical Oceanography from the University of Washington (1992). Following a post-doctoral research appointment at the Woods Hole Oceanographic Institution, he joined the Department of Geological Sciences at the University of South Carolina in 1995. In the summer of 2005, he will join the College of Ocean and Atmospheric Sciences at Oregon State University as an Associate Professor. Dr. Goni's broad scientific interest is the cycling of organic matter in coastal environments using a variety of analytical tools including organic biomarkers and stable isotopes. His studies have ranged from coastal upwelling systems such as the Gulf of California and the Cariaco Basin to river dominated margins in the Gulf of Mexico, Beaufort Sea, Gulf of Papua and estuaries in the Southeast U.S. His recent efforts are focused in understanding how physical, biological and geological mechanisms affect and control the fate of organic matter in continental margins.

Light refreshments are served in the Interaction Area (4th floor of the Oceanography/Physics Building) at 4:00 p.m.

All seminars begin at 3:00 p.m. and are held in room 200 of the Oceanography/Physics building.