Upscaling Simple Models for Energetic Shelf Sediment Transport.

摘要

In the context of EuroSTRATAFORM, the long-term goal of this and a closely related project ( The Role of Negative Buoyancy in the Morphodynamics of River Dominated Shelves: A Global Synthesis ) is to contribute toward simultaneously understanding (i) short term oceanic processes that erode, transport and deposit sediment in the margin system and (ii) the creation of the preserved stratigraphic architecture, seafloor morphology and sediment facies on continental margins. In order for models at such disparate time-scales to interact, they must communicate through expressions which upscale the underlying physical processes. Under Modeling Task D5, the EuroSTRATAFORM white paper specifically states: Coherent techniques will be developed for upscaling individual processes/events into long-term stratigraphic-architecture and seascape-evolution models. Another conclusion common to recent ONR Coastal Geosciences programs is recognition of the dominant role played by episodic, high energy events in driving both sediment transport and bed formation. During STRATAFORM, the majority of across-shelf sediment flux was found to be associated with a few major flood and storm events occurring over just one or two weeks every few years. In its section on modeling, the EuroSTRATAFORM white paper similarly states, Of special concern will be important events of strata formation (e.g., debris flows, extreme floods) that are difficult to observe. Thus another long-term goal of both this upscaling project and its allied global synthesis project is to specifically understand the role of energetic sediment transport in depositing sediment on margins and shaping morphology.