Measurements of Scholte and Stoneley waves in the seabed

Abstract

As a part of the Seabed Characterization Experiment carried out in May 2022 in the New England Mud Patch, Scholte and Stoneley waves in the seabed were generated by the interface wave sediment profiler (iWaSP), a piezoelectric bender beam transducer. The iWaSP was deployed four times during in May. These waves were received at ranges of 40–100 m by bottom-mounted ocean bottom recorders (OBXs) each equipped with a three-axis geophone and hydrophone. Miller et al. (2023) found the speeds of these interface waves to range from 39 to 133 m/s in the first of the four deployments. This paper described the results of the following three deployments. Following the classification suggested by Wilson (P. Wilson, personal communication, July 15, 2023), the layers consist at least four distinguishable sediment layers. The upper-most is a relatively thin, fluid-like layer (1) of mud. Below that lies more rigid mud (2). Below the mud is a sand layer (3) with a thickness of 10 m. Finally, there lies a half-space layer (4) with a higher density and faster compressional and shear speeds. We conclude that the Scholte waves traveled on the 1–2 interface and the Stoneley waves propagated on the 2–3 interface. [Work supported by ONR Code 322OA.]