Inverse modeling of post Last Glacial Maximum transgressive sedimentation using 2D-SedFlux: Application to the northern Adriatic Sea

Abstract A coupled simulation of the hydrologic model HydroTrend and the stratigraphic model 2D-SedFlux is applied to transgressive deposits in the north Adriatic Sea area over the last 21,000 years. Synthetic sediment discharge from the Po River, which increases more than 70% during late Pleistocene compared to those during Holocene due to glacier melt and enlarged drainage area, is employed in the simulation of sediment deposition by the process based, forward model, 2D-SedFlux . Paleo-morphology is reconstructed in a pseudo-inverse manner by comparing the predicted deposit distribution and the modern morphology. Accommodation for thick, prograding deposits in the modern Po delta and the Po lowstand delta are created by drawing back the modern bathymetric profile. The bathymetric profile is then adjusted for aggradational deposits. These sequential simulations produced a likely profile of the paleo-morphology, which had accommodation matching with the sediment supply. Evaluation of effects of waves, however, suggested that the predicted rate of sediment input was too low to produce a prograding delta. A good match with the observation of the modern Po delta was achieved when further adjustments in basin width was properly made.