Detailed composition and physical properties analyses of surficial and sub-surface fined-grained sediments from the Continental Shelf and Upper Slope Sediments Offshore Southern New England, USA

Abstract

In recent years, detailed geological characterization of the seafloor and shallow sub-surface on the northern U.S. Atlantic margin have been an important component of multi-disciplinary ocean acoustics and environmental sensing projects to support experiment planning and inform geoacoustic models of sound propagation. Comprehensive surficial sediment and core sampling across shallow continental shelf, shelf-edge, and upper continental slope sites offshore southern New England provide the opportunity to evaluate the importance of many sediment characteristics that impact sound propagation through the seabed. Beginning in the mid-shelf New England Mud Patch and continuing into deeper water, we have begun to develop a detailed understanding of the composition and physical properties of the shallow sediment column record using a combination of surficial and sub-surface sediment sampling tools, coupled with an extensive suite of discrete laboratory analyses. Quantitative data on sediment density, porosity, mineral and biogenic composition, and grain size distribution provides both valuable input parameters for geoacoustic models and helps establish a framework for interpreting independently derived measurements and modeling results. The physical, biological, and other environmental sediment characteristics can be integrated with existing geological assessments of the region and used to investigate ocean and sub-surface acoustic propagation. [Work supported by the Office of Naval Research.]