Physics of Sound in Marine Sediments

ISBN-13: 9781468408409 / Angielski / Miękka / 2012 / 569 str.

Lloyd Hampton

Opis

The phenomenon of sound transmissions through marine sediments is of extreme interest to both the United States civilian and Navy research communities. Both communities have conducted research within the field of this phenomenon approaching it from different perspectives. The academic research community has approached it as a technique for studying sedimentary and crustal structures of the ocean basins. The Navy research community has approached it as an additional variable in the predictability of sound trans- mission through oceanic waters. In order to join these diverse talents, with the principal aim of bringing into sharp focus the state-of-the-science in the problems relating to the behavior of sound in marine sediments, the Office of Naval Research organized and sponsored an invited symposium on this subject. The papers published in this volume are the results of this symposium and mark the frontiers in the state-of-the-art. The symposia series were based on five research areas identified by ONR as being particularly suitable for critical review and for the appraisal of future research trends. These areas include: 1. Physics of Sound in Marine Sediments, 2. Physical and Engineering Properties of Deep-Sea Sediments, 3. The Role of Bottom Currents in Sea Floor Geological Processes, 4. Nephelometry and the Optical Properties of the Ocean I'laters, S. Natural Gases in Marine Sediments and Their Mode of Distribution. These five areas also form some of the research priorities of the ONR program in Marine Geology and Geophysics.

Spis treści

I. Theory.- A. Derivation.- A Review of the Derivations of the Formulas for the Acoustical Properties of Liquid-Solid Mixtures.- Acoustic Waves in Saturated Sediments.- B. Interpretation.- Acoustic and Mechanical Loading of Marine Sediments.- Influence of Anisotropy and Soil Structure on Elastic Properties of Sediments.- The Seismic Wide Angle Reflection Method in the Study of Ocean Sediment Velocity Structure.- Sonobuoy Measurements in Thin Layers.- II. Applications.- The Interaction of Underwater Acoustics and Marine Geophysics.- Underwater Sound Transmission Through the Ocean Floor.- Geoacoustic Models of the Sea Floor.- Sound Propagation Calculations Using Bottom Reflection Functions.- III. Measurement Techniques.- Nonlinear Acoustics and Its Role in the Sedimentary Geophysics of the Sea.- Near-Bottom Acoustic Observations of Abyssal Topography and Reflectivity.- Remote Sediment Classification Potential of Reflected Acoustic Signals.- Measurement of Viscoelastic Properties of Sediments Using a Torsionally Vibrating Probe.- A Method for Measuring In Situ Acoustic Properties During Sediment Coring.- IV. Measurement Results.- Acoustic Estimates of the Topography and Roughness Spectrum of the Sea Floor Southwest of Iberian Peninsula.- Acoustical Characteristics of the Sea Floor: Experimental Techniques and Some Examples from the Mediterranean Sea.- Statistical Correlation of Physical Properties and Sound Velocity in Sediments.- Preliminary Study of Global Sediment Sound Velocities from Sonobuoy Data.- Measurements of Reflectivity by Explosive Signals.