HR: 1340h
AN: OS23C-1322    [Abstracts]
TI: Process Based Long Term Simulation of Shelf Stratigraphy Evolution
AU: * Das, H S
EM: himangshu_das@urscorp.com
AF: URS Corporation, 3676 Hartsfield Road, Tallahassee, FL 32303 United States
AU: Reed, C W
EM: chris_reed@urscorp.com
AF: URS Corporation, 3676 Hartsfield Road, Tallahassee, FL 32303 United States
AU: Niedoroda, A W
EM: alan_niedoroda@urscorp.com
AF: URS Corporation, 3676 Hartsfield Road, Tallahassee, FL 32303 United States
AB: The Adriatic Sea has been the location of several extensive data collection programs over the past three years. The EuroStrataform and ComDelta have been supported by the U.S. Office of Naval Research (EuroStrataform) and the European Union respectively and have focused on problems of marine sedimentation and stratigraphy. The National Oceanographic Partnership Program (NOPP) has acquired and collected a wealth of hydrographic and circulation data. In addition, a number of sophisticated numerical models have been applied to physical oceanographic and marine geological investigations. The overall effort has been to develop a very rich data set concentrated within the Adriatic Sea. The existence of these data and model results has allowed us to develop and test models that relate the formation of sedimentary strata on the Italian Adriatic shelf to basic factors such as sediment supply and wind and wave forcing. The model framework follows this development from the supply of sediment to the coastal systems by the Po River and other small rivers draining the eastern slopes of the coastal Appenine Mountains to the ultimate burial of sediment beneath the zone of storm reworking. A major step has been the nesting of a detailed shelf sediment dynamics model (M3D) into the regional ROMS circulation model that has been modified at WHOI to include marine sediment transport processes. The ROMS model has been configured to extend over the entire Adriatic. The M3D model covers a subregion (100 km x 120 km) of the central Italian shelf with a more detailed grid resolution. This model also tracks the time-varying bed composition and the formation of the near-bed shelf stratigraphy. The ROMS model provides the regional circulation patterns for time periods on the order of months. These data are used as boundary conditions in the M3D model. Because the detailed M3D model is directed at representing the long term sedimentation patterns that result in the formation of shelf strata it has been necessary to develop methods to extend the relatively short time series from the ROMS model (months) to representations of processes with much longer durations (decades). Long term wind records have been analyzed to develop statistical characterizations of Scirocco and Bora wind events. The events captured during the measurement period have been compared to these long term statistics and routines have been developed to scale and extend the boundary forcing of the M3D model accordingly. Although these procedures are inherently stochastic, they provide the fundamental outline of how detailed hydrodynamic and sediment-dynamic models can be employed to simulate the development of near-bed shelf stratigraphy over geologically relevant (centuries to millennia) time intervals.
DE: 4556 Sea level variations
DE: 4558 Sediment transport
DE: 3022 Marine sediments--processes and transport
DE: 3210 Modeling
SC: Ocean Sciences [OS]
MN: 2004 AGU Fall Meeting