Acoustics of in Situ and Laboratory Sediments


Book Description

During the period 1 January to 31 December, 1977, work under Contract N00014-76-C-0117 consisted of three parts: (1) in situ determination of compressional wave speed in ocean sediments using the ARL:UT profilometer; (2) development of transducers to measure shear wave and acoustic impedance parameters of sediments both in situ and in the laboratory; and (3) laboratory measurement of shear wave and compressional wave parameters of real and artificial sediments. Data obtained for the three parts of the program are reported.




Laboratory and in Situ Sediment Acoustics


Book Description

During this reporting period, research was directed towards measuring sediment acoustic parameters in situ. Four field trips were made to use the ARL profilometer to make in situ sound speed measurements. Laboratory work continued to add the capability of measuring shear wave speed and acoustic impedance to the existing profilometer. Shear wave and compressional wave data measured in laboratory sediments are reported.




Acoustical Properties of Laboratory and in Situ Sediments


Book Description

This report summarizes work done during the period 1 August 1975-30 June 1983. Major accomplishments include: Development and use of instrumentation to perform in situ measurements of acoustical parameters of marine sediments, measurement of shear and compressional wave parameters of laboratory sediments, development of theoretical descriptions of acoustic propagation in sediments, and laboratory experiments to test various theoretical models of propagation in sediments.










Strength Testing of Marine Sediments


Book Description

Philadelphia, PA : ASTM, 1985.




Sediment Acoustics


Book Description

Sediment Acoustics describes the development of a mathematical model to be used to predict the propagation characteristics of acoustic waves in marine sediments. The model is based on the classical theory of Maurice Biot. Over the past 20 years, R.D. Stoll has published many technical papers covering various stages of development and different applications of Biot's theory. This work is summarized in one reference volume for the first time and presents enough introductory material so that researchers and students may use the model without extensive literature searches. Scientists working in the areas of acoustical oceanography, marine seismology, and ocean engineering will find this monograph useful in predicting the wave velocity and attenuation of seafloor sediments based on the geology of an area and such measurable physical properties as porosity and geostatic stress. A simple, interactive computer program is given as an aid in calculating velocity and attenuation, and a number of examples from recent field experiments are presented so that the predictions of the model may be compared with the "ground truth."




Acoustics of the Seabed as a Poroelastic Medium


Book Description

This book presents a concise description of the acoustics of ocean sediment acoustics, including the latest developments that address the discrepancies between theoretical models and experimental measurements. This work should be of interest to ocean acoustic engineers and physicists, as well as graduate students and course instructors. The seabed is neither a liquid nor a solid, but a fluid saturated porous material that obeys the wave equations of a poroelastic medium, which are significantly more complicated than the equations of either a liquid or a solid. This volume presents a model of seabed acoustics with input parameters that allow the model to cover a wide range of sediment types. The author includes example reflection and transmission curves which may be used as typical for a range of sediment types. The contents of this book will allow the reader to understand the physical processes involved in the reflection, propagation, and attenuation of sound and shear waves in ocean sediments and to model the acoustic properties for a wide range of applications.




Laboratory and Field Studies of Sediment Acoustics


Book Description

Work under Contract consisted of three parts: (1) redesign and updating of the ARL:UT profilometer system used to measure in situ sound velocities of ocean bottom sediments, (2) development of transducers to measure shear wave and acoustic impedance parameters of sediments, and (3) laboratory measurements to develop and confirm theoretical models for acoustic propagation in sediments. Data obtained for the three parts of the program are reported.




Sediment Acoustics


Book Description

During the period 1 January - 31 December 1979, work under Contract N00014-76-C-0117 consisted of three parts: (1) use of the profilometer system to obtain in situ compressional wave data and to test in situ shear wave transducers, (2) development of theoretical models for acoustic propagation in sediments, and (3) laboratory measurements of compressional wave and shear wave parameters in laboratory sediments. Data obtained for the three parts of the program are reported. (Author).