Ebook: Shear Waves in Marine Sediments

Shear waves and closely related interface waves (Rayleigh, Stoneley and Scholte) play an important role in many areas of engineering, geophysics and underwater acoustics. In some cases interest is focused on large-amplitude waves of low frequency such as those associ­ ated with earthquakes and nuclear explosions; in other cases low amplitude waves, which have often travelled great distances through the sediment, are of interest. Both low and high frequency shear and interface waves are often used for seafloor probing and sediment characterization. As a result of the wide spectrum of different interests, different disciplines have developed lines of research and a literature particularly suited to their own problems. For example water-column acousticians view the seafloor sediment as the lower boundary of their domain and are interested in shear and interface waves in the near bottom sediments mainly from the standpoint of how they influence absorption and reflection at this boundary. On the other hand, geophysicists seeking deep oil deposits are interested in the maximum penetration into the sediments and the tell-tale characteristics of the seismic waves that have encountered potential oil or gas bearing strata. In another area, geotechnical engineers use shear and interface waves to study soil properties necessary for the design and the siting of seafloor structures.

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Content:
Front Matter....Pages i-xv
Front Matter....Pages 1-1
Shear Waves in Marine Sediments — Bridging the Gap from Theory to Field Applications....Pages 3-12
Surface Waves in Poro-Viscoelastic Marine Sediments....Pages 13-20
An Investigation of Causality for Biot Models by Using Kramers-Kr?nig Relations....Pages 21-28
Soil Properties for Shear Wave Propagation....Pages 29-39
The Relevance of Shear Waves for Structural Subsurface Investigations....Pages 41-49
Experimental Investigation of Seismic Surface Waves in the Seafloor....Pages 51-58
Laboratory Studies on Pulsed Leaky Rayleigh Wave Components in a Water Layer Over a Solid Bottom....Pages 59-66
Assessment of Shear Strength of the Sea Bottom from Shear Wave Velocity Measurements on Box Cores and In-situ....Pages 67-74
Numerical Modelling and Laboratory Experiments on Underwater Sound Propagation Over a Shear Supporting Bottom....Pages 75-81
A Review of Laboratory Shear Wave Techniques and Attenuation Measurements with Particular Reference to the Resonant Column....Pages 83-93
Relationship Between Acoustic and Mechanical Properties of Two Marine Clays....Pages 95-102
A Laboratory Method to Investigate Shear Waves in a Soft Soil Consolidating Under Self Weight....Pages 103-110
Laboratory Measurements of Acoustic Properties of Periplatform Carbonate Sediments....Pages 111-120
Comparison of Measured Compressional and Shear Wave Velocity Values with Predictions from Biot Theory....Pages 121-130
Wave Velocities in Sediments....Pages 131-140
Shear Wave Attenuation in Unconsolidated Laboratory Sediments....Pages 141-147
Shear Wave Velocities of Glacio-Marine Sediments: Barents Sea....Pages 149-156
Rock Acoustics: Relevance of the Porous Viscoelastic Model....Pages 157-166
Influence of Stress State and Stress History on Acoustic Wave Propagation in Sedimentary Rocks....Pages 167-174
Front Matter....Pages 175-175
A Summary of DREA Observations of Interface Waves at the Seabed....Pages 177-184
Front Matter....Pages 175-175
Observations of the Relative Contributions of Waterborne and Sediment Paths to the Received Acoustic Signal....Pages 185-193
Shear-Wave Anisotropy in Marine Sediments Around Britain from Surface Sources....Pages 195-202
Refraction Measurement of Shear Wave Anisotropy in Shallow Marine Sediments and Implications for Reflection Processing....Pages 203-212
Spatial Variability in Ground Motion: Effects of Material Heterogeneity in Seafloor Sediments....Pages 213-219
Implications of Deep-Water Seismometer Array Measurements for Scholte Wave Propagation....Pages 221-230
Shear Wave Velocity Structure from Interface Waves at Two Deep Water Sites in the Pacific Ocean....Pages 231-238
The Effects of Shear Velocity Structure on Seafloor Noise....Pages 239-245
Concurrent Observations of Directional Spectra of Ocean Surface Waves and Microseisms from an Ocean Subbottom Seismometer (OSS) Array....Pages 247-256
Wave Propagation in a Borehole....Pages 257-265
Application of Shear Wave Measurements in Boreholes....Pages 267-274
Experience with the Seismic Cone Penetrometer in Offshore Site Investigations....Pages 275-282
Comparison of Techniques for Shear Wave Velocity and Attenuation Measurements....Pages 283-294
Shear Wave Velocity Gradients in Near-Surface Marine Sediment....Pages 295-304
ISSAMS: An In Situ Sediment Acoustic Measurement System....Pages 305-312
Small-Scale In Situ Measurements of S-H Velocity in Surficial Sedimentary Deposits: Localised Textural and Biological Controls....Pages 313-320
In Situ Measurements of Shear-Wave Velocity in Ocean Sediments....Pages 321-328
Seafloor Shear Wave Velocity Data Acquisition: Procedures and Pitfalls....Pages 329-336
Mapping of the Sea Bed Via In Situ Shear Wave (SH) Velocities....Pages 337-343
Observations of Split Shear-Waves from Young Ocean Crust....Pages 345-352
Estimation of Shear-Wave Speed in Ocean-Bottom Sediments by Comparing Oblique-angle Reflectivity Measurements with Normal Incidence Data....Pages 353-360
Front Matter....Pages 175-175
Constraints on Shear Velocities in Deep-Ocean Sediments as Determined from Deep-Tow Multichannel Seismic Data....Pages 361-368
Changes in P and S Velocities Caused by Subduction Related Sediment Accretion Off Washington/Oregon....Pages 369-378
Compressional and Shear Wave Velocities in the Upper Crust....Pages 379-386
Sedimentary Shear Modulus and Shear Speed Profiles from a Gravity Wave Inversion....Pages 387-394
Measurements of Compressional Wave and Shear Wave Speeds, Attenuation, Permeability, and Porosity in Marine Sediments....Pages 395-402
Sea-Bed Shear Moduli from Measurements of Tidally Induced Pore Pressures....Pages 403-410
Front Matter....Pages 411-418
Excess Attenuation in Low-Frequency Shallow-Water Acoustics: A Shear Wave Effect?....Pages 419-419
Sensitivity of Bottom Loss to Attenuation and Shear Conversion....Pages 421-430
The Effect of Shear Wave Attenuation on Acoustic Bottom Loss Resonance in Marine Sediments....Pages 431-438
The Influence of Sediment Rigidity on the Plane-Wave Reflection Coefficient....Pages 439-446
Shear Wave Conversion Due to Subbottom Facets....Pages 447-454
A Seismo-Acoustic Finite Element Model for Underwater Acoustic Propagation....Pages 455-462
Finite Difference Modelling of Shear Waves....Pages 463-470
A Stable Higher-Order Elastic Parabolic Equation with Application to Scholte Wave Propagation....Pages 471-478
ELASTIC_PE: A Parabolic Approximation for Propagation Modelling of Shear Wave Effects in Sediment Layers....Pages 479-486
Computation of Shear Waves by Integral Equations Methods in Stratified Media....Pages 487-494
Normal Modes Identification in Shallow Water Using Spectral Analysis: Theory and Experiments....Pages 495-502
Estimation of Geoacoustic Properties by Inversion of Acoustic Field Data....Pages 503-509
A Fast Simulated Annealing Algorithm for the Inversion of Marine Sediment Seismo-Acoustic Parameters....Pages 511-520
Front Matter....Pages 521-528
Determination of the Sediment Shear Speed Profiles from Phase and Group Velocity Dispersion Data of SH Wave....Pages 419-419
Measurement of the Elastic Properties of the Ocean Bottom by Inversion of Reflection Amplitude Data....Pages 529-536
Surface Wave Inversion for Shear Wave Velocity....Pages 537-544
Determination of Shear Velocity Profiles by Inversion of Interface Wave Data....Pages 545-556
Using Synthetic Seismograms to Determine Shear Wave Velocities in Sediments from Ocean Bottom Seismometer Refraction Observations....Pages 557-565
Analytical Investigation of Seismic Surface Waves in the Seafloor....Pages 567-574
Back Matter....Pages 575-582
....Pages 583-593