Shipboard low frequency sound speed measurements in the New England Mud Patch

Muddy ocean bottoms have been shown to be acoustically softer than the water column, presenting challenges in resolving inverse problems such as in remote parameter sensing and target detection. In addition, the acoustic properties of mud are less adequately understood compared to sandy sediments. As part of the Sediment Characterization Experiment, a survey cruise was conducted in August 2015 in the New England Mud Patch, in order to further study the acoustic properties of mud. 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. Samples were extracted from within the multicores and transferred to a resonator tube, where shipboard low frequency laboratory measurements of sound speed were performed. Before discarding the sample, it was perturbed and allowed to settle in the resonator over a period of two days, during which low frequency sound speed measurements were taken. Experimental ...