Seabed Dynamics in the Adriatic Sea and Western Gulf of Lions

摘要

The ultimate objective of this research program is to obtain a predictive understanding of the physical and biological processes responsible for the formation, alteration and preservation of sedimentary strata on continental margins. The general approach is to use focused field observations and measurements to develop and test hypotheses. During the past triennium this project has transitioned between analyses of data collected in the Adriatic Sea during FY01-03, conducting fieldwork in the Gulf of Lions (GOL) in FY05, and completing overall analyses from both locations in FY06. The Adriatic research has had two broad objectives. First, we are testing the idea that river-ocean coherence has a first-order impact on the initial distribution and character of strata in the coastal ocean. In particular, we hypothesize that moderate sized rivers (e.g., Po, approximately 105 km2), in which discharge peaks are decoupled from oceanic conditions, produce thick beds that have large horizontal continuity and significant vertical (i.e., temporal) variation in physical properties. In contrast, small rivers (e.g., Apennine rivers, Eel, approximately 104 km2) produce thin beds, which due to subsequent bioturbation have low horizontal continuity and little vertical variability. Second, we are exploring the idea that large-scale spatial variability in sediment erodibility may control accumulation rate patterns that have been observed in the western Adriatic (Po River to Gargano peninsula).