CA Seabed 3

Our interdisciplinary team proposes to test the overarching hypothesis that organic matter input to the deep sea drives biological processes that modify geotechnical and geoacoustic properties of the surface layer of sediments. We will explore the spatial and temporal variability and relationships among these properties in the central California slope. This region experiences seasonal and interannual variability in organic matter deposition to the seabed and spatial variability in the infaunal community. We plan to combine seasonal sampling of geological, geotechnical, geoacoustic, biological, and biogeochemical properties along a spatial gradient with high temporal resolution sampling of the bottom boundary layer and seabed surface. Our results will provide insight on the patterns of seabed properties and the mechanisms driving those patterns and will improve our ability to predict and remotely detect changes in deep sea sediments. In this project we aim to use cutting-edge abyssal direct observing and remote sensing techniques including dense thermistor moorings, dye releases, acoustic reflection and scattering measurements, direct turbulence measuring autonomous floats, direct measurements of sediment load, particle size and settling velocity distribution, and bioacoustics in order to synthesize a complete interdisciplinary picture of the deep sea benthic boundary layer.