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The Waipaoa River Sedimentary System in New Zealand, a focus site of the MARGINS Source-to-Sink program, contains both a terrestrial and marine component. Poverty Bay serves as the interface between the fluvial and oceanic portions of this dispersal system. This study used a three-dimensional hydrodynamic and sediment-transport numerical model, the Regional Ocean Modeling System (ROMS), coupled to the Simulated WAves Nearshore (SWAN) wave model to investigate sediment-transport dynamics within Poverty Bay and the mechanisms by which sediment travels from the Waipaoa River to the continental shelf. Two sets of model calculations were analyzed; the first represented a winter storm season, January–September, 2006; and the second an approximately 40 year recurrence interval storm that occurred on 21–23 October 2005. Model results indicated that hydrodynamics and sediment-transport pathways within Poverty Bay differed during wet storms that included river runoff and locally generated waves, compared to dry storms driven by oceanic swell. During wet storms the model estimated significant deposition within Poverty Bay, although much of the discharged sediment was exported from the Bay during the discharge pulse. Later resuspension events generated by Southern Ocean swell reworked and modified the initial deposit, providing subsequent pulses of sediment from the Bay to the continental shelf. In this manner, transit through Poverty Bay modified the input fluvial signal, so that the sediment characteristics and timing of export to the continental shelf differed from the Waipaoa River discharge. Sensitivity studies showed that feedback mechanisms between sediment-transport, currents, and waves were important within the model calculations. [ABSTRACT FROM AUTHOR]

While the role of shore-parallel transport is extensively documented, its contribution to source-to-sink and provenance studies is often overshadowed by tectonic variations, sediment influx, and sea-level change. To isolate the sedimentary contribution of shore-parallel transport, this study examines the central Levant continental margin (easternmost Mediterranean), where the other three factors are well constrained. New high-resolution multibeam and seismic reflection data collected in a dedicated cruise aboard the RV Bat Galim are used for analyzing current-indicating morphologies formed since the Last Glacial Maximum (LGM). Results show six different current indicators, which attest to the ongoing shore-parallel Levant Jet System (LJS) flow. Throughout the post-LGM transgression and coastal retreat, the LJS shifted landward to flow over the submerged shelf and upper slope. This shift, along with periodic/seasonal alterations in the flow intensity, regulated the sediment transport, distribution and erosion, along and across the margin, during the lowstand, transgression, and highstand conditions. This case study emphasizes the central role of shore-parallel currents in regulating the sedimentary budget. It provides a reference case for continental margins where the shore-parallel role is obscured by more dominant tectonic-eustatic-sedimentation factors. • New high-resolution multibeam and Chirp data from the central Levant continental margin (easternmost Mediterranean). • The tectonic, eustatic, and sedimentation factors are well constrained in the study area. • The study examines the shore-parallel sediment transport role in shelf build-up. • Shore-parallel currents regulate sediment transport, distribution, and erosion, along and across the margin. [ABSTRACT FROM AUTHOR]