MURI Towards an integrative understanding of near-surface seabed structure and stability in the deep sea

Abstract

Approved for Public ReleaseNaval and engineering applications in the deep sea are expanding, especially in the seabed surface layer, e.g., use of smaller, unmanned submersibles for surveying strategically important areas; deployment, anchoring, and retrieval of instrumentation; burial of deep-sea cables; leveraging sediment redox conditions to power equipment. These applications require an improved, integrative understanding of the seabed that includes short-term changes driven by biological and hydrodynamic processes, aswell as tools for remote sensing of seabed properties. 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. In testing this hypothesis, we will explore the spatial and temporal variability and relationships among these properties subject to forcing from bottom currents within a highly productiveregion of the ocean, the central California continental margin. This region experiences seasonal and interannual variability in organic matter and sediment deposition to the seabed and spatial variability in the infaunal community influenced by water depth, bottom water oxygen, and lateral transport. We plan to combineseasonal sampling of geological, geotechnical, geoacoustic, biological, and biogeochemical properties along a depth gradient from continental slope to abyssal plain with high-temporal-resolution sampling of the bottom boundary layer and seabed surface. Our results will provide insight on the patterns of seabed structure and stability and the mechanisms driving those patterns, and will improveour ability to predict and remotely detect related changes in deep sea sediments.

Document Details

Document Type
DoD Grant Award
Publication Date
Nov 08, 2024
Source ID
N000142412559

Entities

People

  • Gabriel R. Venegas

Organizations

  • Office of Naval Research
  • United States Navy
  • University System of New Hampshire

Tags

Fields of Study

  • Environmental science

Readers

  • Coastal Oceanography
  • Geotechnical Engineering.

Technology Areas

  • Autonomy