DURIP Deep-Sea Multi-Coring System for Investigation of Coupled Benthic Boundary Layer Processes and Supporting Unified Seabed Model Development
Abstract
The deep-sea benthic boundary layer is a highly complex system with coupled hydrodynamic, geological, biological, and chemical processes. Transport, bioturbation, and biogeochemical processes can influence sediment geotechnical properties, such as porosity, grainsize, permeability, and viscoelasticity, and their effects contribute to spatiotemporal variability in seabed geoacoustic properties, such as sediment sound speed and attenuation, bulk and interface shear wave propagation, and seabed acoustic reflectivity, which can have impacts on sonar-based sensing of the seabed. To investigate how benthic processes couple to deep seabed spatiotemporal acoustic variability, a new instrument is proposed. The multi-sensor instrument will consist of a deep-sea-ready multi-corer outfitted with two sets of compressional and shear wave probes, which will allow for direct measurement of seabed compressional and shear speed and attenuation along with simultaneous collection of cores for analysisof infauna community structure and sediment geotechnicaland geochemical properties. Additional probes inserted into the seabed will acquire profiles of sediment temperature and conductivity. The measurement system will also be outfitted with high-accuracy oceanographic instrumentation for characterizing bottom water temperature, conductivity, dissolved oxygen, pH, and turbidity, as well as a high-resolution imaging system. Finally, the Acoustic Coring System, a gravity corer-based instrument, will be upgraded to sample deeper into the sediment, providing complementary measurements of the upper 3 to 6 meters of the seabed. Both systems will be capable of ocean depths up to 6000 m. The proposed instrumentation will provide detailed in situ observations to directly investigate coupling between seabed transport, macro- and micro-biological, chemical, and thermal phenomena with geotechnical and geoacoustic properties. Such observations are needed to establish and test future unified predictive seabed models. Finally, the proposed system will support education and training of future scientists and engineers in the ocean acoustics field.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Nov 08, 2024
- Source ID
- N000142412587
Entities
People
- Kevin M. Lee
Organizations
- Office of Naval Research
- United States Navy
- University of Texas at Austin