Shear Waves in Marine Sediments

Shear Waves in Marine Sediments PDF Author: J.M Hovem
Publisher: Springer Science & Business Media
ISBN: 9401135681
Category : Science
Languages : en
Pages : 593

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Book Description
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.

Shear Waves in Marine Sediments

Shear Waves in Marine Sediments PDF Author: J.M Hovem
Publisher: Springer Science & Business Media
ISBN: 9401135681
Category : Science
Languages : en
Pages : 593

Get Book

Book Description
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.

In Situ Determinations of the Velocities of Compressional and Shear Waves in Marine Sediments from a Research Submersible

In Situ Determinations of the Velocities of Compressional and Shear Waves in Marine Sediments from a Research Submersible PDF Author:
Publisher:
ISBN:
Category : Marine sediments
Languages : en
Pages : 30

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Book Description
In situ measurements were made of the velocity and attenuation of compressional waves and of velocities of Stoneley waves (from which shear-wave velocities were computed) at six stations in the sea floor off San Diego, California. Water depths ranged from 20 to 1130 meters, and sediment types ranged from medium sand to clayey silt. Sediment densities, porosities, and grain sizes were measured in samples taken at each station. The unique data obtained allowed tentative evaluations of models and equations, and computation of constants, for elastic and viscoelastic saturated, porous media. (Author).

Sound Velocity, Elasticity, and Related Properties of Marine Sediments, North Pacific

Sound Velocity, Elasticity, and Related Properties of Marine Sediments, North Pacific PDF Author: Edwin Lee Hamilton
Publisher:
ISBN:
Category : Marine sediments
Languages : en
Pages : 234

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Book Description


Physics of Sound in Marine Sediments

Physics of Sound in Marine Sediments PDF Author: Lloyd Hampton
Publisher: Springer Science & Business Media
ISBN: 1468408380
Category : Science
Languages : en
Pages : 568

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Book Description
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.

Interactions Between Macro- and Microorganisms in Marine Sediments

Interactions Between Macro- and Microorganisms in Marine Sediments PDF Author:
Publisher: American Geophysical Union
ISBN: 087590274X
Category : Science
Languages : en
Pages : 391

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Book Description
Marine sediments support complex interactions between macro-and microorganisms that have global implications for carbon and nutrient cycles. What is the state of the science on such interactions from coastal and estuarine environments to the deep sea? How does such knowledge effect environmental management? And what does future research hold in store for scientists, engineers, resource managers, and educators?Interactions between Macro- and Microorganisms in Marine Sediments responds to these questions, and more, by focusing on:? Interactions between plants, microorganisms, and marine sediment? Interactions between animals, microorganisms, and marine sediment? Interactions between macro- and microorganisms and the structuring of benthic communities? Impact of macrobenthic activity on microbially-mediated geochemical cycles in sediments? Conceptual and numeric models of diagenesis that incorporate interactions between macro- and microorganismsHere is an authoritative overview of the research, experimentation and modeling approaches now in use in our rapidly evolving understanding of life in marine sediments.

Ocean Seismo-Acoustics

Ocean Seismo-Acoustics PDF Author: T. Akal
Publisher: Springer Science & Business Media
ISBN: 1461322014
Category : Science
Languages : en
Pages : 898

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Book Description
Seafloor investigation has long been a feature of not only seismology but also of acoustics. Indeed it was acoustics that produced depth sounders, giving us the first capability of producing both global and local maps of the seafloor. Subsequently, better instrumentation and techniques led to a clearer, more quantitative picture of the seabed itself, which stimulated new hypotheses such as seafloor spreading through the availability of more reliable data on sediment thickness over ocean basins and other bottom features. Geologists and geophysicists have used both acoustic and seismic methods to study the seabed by considering the propagation of signals arising from both natural seismic events and man-made impulsive sources. Although significant advances have been made in instrumentation, such as long towed geophysical arrays, ai r guns and ocean bot tom seismometers, the pic ture of the seafloor is still far from complete. Underwater acoustics concerns itself today with the phenomena of propagation and noise at frequencies and ranges that require an understanding of acoustic interaction at both of its boundaries, the sea surface and seafloor, over depths ranging from tens to thousands of meters. Much of the earlier higher frequency (>1 kHz) work included the characterization of the seafloor in regimes of reflection coefficients which were empirically derived from surveys. The results of these studies met with only limited success, confined as they were to those areas where survey data existed and lacking a physical understanding of the processes of reflection and scattering.

Sediment Acoustics

Sediment Acoustics PDF Author: Robert D. Stoll
Publisher: Springer
ISBN:
Category : Science
Languages : en
Pages : 172

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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."

Microstructure of Fine-Grained Sediments

Microstructure of Fine-Grained Sediments PDF Author: Richard Harold Bennett
Publisher: Springer Science & Business Media
ISBN: 9780387973395
Category : Science
Languages : en
Pages : 614

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Book Description
Knowledge of basic clay microstructure is fundamental to an understanding of the physical, chemical, and mechanical properties of fine-grained sediments and rocks. This compilation of fifty-nine peer-reviewed papers examines clay microstructure in detail with comprehensive sections focusing on microstructure signatures, environmental processes, modeling, measurement techniques, and future research recommendations. Many of these topics are discussed in light of geological and engineering applications, such as hazardous waste disposal, construction techniques, and drilling programs. The field of clay microstructure is developing rapidly. The concepts, observations, and principles presented in this book will help stimulate new thought and be a "spring board" for exciting new research.

Mechanics of Coastal Sediment Transport

Mechanics of Coastal Sediment Transport PDF Author: J?rgen Freds?e
Publisher: World Scientific
ISBN: 9789810208400
Category : Science
Languages : en
Pages : 406

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Book Description
This book treats the subject of sediment transport in the marine environment, covering transport of non-cohesive sediment by waves and current in- and outside the surf zone. It can be read independently, but a background in hydraulics and basic wave mechanics is required. It is intended for M.Sc. and Ph.D. students. The primary aim of the book is to describe the physical processes of sediment transport and how to represent them in mathematical models. It does not present a large number of different formulae for the sediment transport rates under various conditions. The book can be divided in two main parts; in the first, the relevant hydrodynamic theory is described; in the second, sediment transport and morphological development are treated. The hydrodynamic part contains a review of elementary theory for water waves, chapters on the turbulent wave boundary layer and the turbulent interaction between waves and currents, and finally, surf zone hydrodynamics and wave driven currents. The part on sediment transport introduces the basic concepts (critical bed shear stress, bed load, suspended load and sheet layer, near-bed concentration, effect of sloping bed); it treats suspended sediment in waves and current and in the surf zone, and current and wave-generated bed forms. Finally, the modelling of cross-shore and long-shore sediment transport is described together with the development, of coastal profiles and coastlines.

Atlas of Structural Geological Interpretation from Seismic Images

Atlas of Structural Geological Interpretation from Seismic Images PDF Author: Achyuta Ayan Misra
Publisher: John Wiley & Sons
ISBN: 111915832X
Category : Science
Languages : en
Pages : 287

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Book Description
This comprehensive book deals primarily with reflection seismic data in the hydrocarbon industry. It brings together seismic examples from North and South America, Africa, Europe, Asia and Australia and features contributions from eleven international authors who are experts in their field. It provides structural geological examples with full-color illustrations and explanations so that students and industry professionals can get a better understanding of what they are being taught. It also shows seismic images in black and white print and covers compression related structures. Representing a compilation of examples for different types of geological structures, Atlas of Structural Geological Interpretation from Seismic Images is a quick guide to finding analogous structures. It provides extensive coverage of seismic expression of different geological structures, faults, folds, mobile substrates (shale and salt), tectonic and regional structures, and common pitfalls in interpretation. The book also includes an un-interpreted seismic section for every interpreted section so that readers can feel free to draw their own conclusion as per their conceptualization. Provides authoritative source of methodologies for seismic interpretation Indicates sources of uncertainty and give alternative interpretations Directly benefits those working in petroleum industries Includes case studies from a variety of tectonic regimes Atlas of Structural Geological Interpretation from Seismic Images is primarily designed for graduate students in Earth Sciences, researchers, and new entrants in industry who are interested in seismic interpretation.