Preliminary characterization of surficial sediment acoustic properties and infauna in the New England Mud Patch

Abstract

Biology is prevalent on and within many ocean bottom sediments. Organisms can include animals dwelling at or near the water-sediment interface or infauna living within surficial sediments. Bioturbation from burrowing, tube building, or other activities can have physical effects on the sediment acoustic properties. As part of the Sediment Characterization Experiment, a survey cruise was conducted in August 2015 in the New England Mud Patch, a region in the Atlantic continental shelf characterized by a layer of mud up to 12 meters thick overlying a sandy subbottom. In addition to gravity coring operations to determine the properties of the mud layer, box cores and multicores were collected to examine the surficial sediment properties. Infauna were prevalent in the interfacial sediment samples and were collected and characterized for body size, hardness, and potential for bioturbation. Shipboard measurements of shear and compressional waves were performed on the box core samples using time-of-flight measurements. Preliminary results from the infauna analysis and the shipboard acoustic measurements are presented.