The proposed work will focus on the continental slope of the MARGINS' Source-to-Sink focus site offshore Waipaoa with three broad questions in mind: 1) whether the main depocenter has changed during the late Holocene; 2) are sediment gravity flows a significant mode of dispersal, and thus do tectonic features on the margin serve as conduits; and 3) does active intra-slope sediment redistribution overwhelm the large terrestrial input signals. The project will conduct a Chirp seismic survey and obtain cores, augmented by existing multibeam data. Sediment accumulation and mixing rates will be studied with short half-life radio-nucleides. Tephra layers may also provide critical chronology.
