Download or read book Acoustical Properties of Sediments written by and published by . This book was released on 1982 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt: The work consisted of (1) final development of the ARL:UT profilometer recorder and transducer to enable the in situ measurement of compressional wave, shear wave, acoustic impedance, and static shear strength of ocean bottom sediments during geophysical coring, and (2) laboratory acoustical measurements on artificial sediments to test predictions of the Hovem model when the pore fluid viscosity is varied. The new profilometer recorder and transducer are described in detail as well as the microcomputer band playback system. Data obtained from the laboratory measurements are displayed.
Download or read book Acoustical and Engineering Properties of Sediments written by Donald J. Shirley and published by . This book was released on 1975 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt: As part of a program of in situ acoustical measurements in ocean sediments, an experimental investigation was started in order to examine the feasibility of measuring shear wave speed, shear wave attenuation, and bulk density by using instruments similar to the compressional wave profilometer developed previously. Measurements were made of the shear wave speed and attenuation in high porosity koalinite clay as the clay consolidated over a period of time. Experimential and theoretical investigation of the measurement of bulk density by acoustical means indicates that the radiation impedance of a driven piezoelectric ceramic transducer can be determined by measuring the electrical input to the transducer. Preliminary measurements of these parameters are reported. As an adjunct to the other measurements, physical properties of the sediments used in the laboratory measurements were determined and are reported.
Download or read book Physics of Sound in Marine Sediments written by Lloyd Hampton and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 568 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Acoustic Properties of Sediments at Weapons Test Ranges of the Naval Undersea Warfare Engineering Station Keyport Washington written by and published by . This book was released on 1979 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt: Estimates are made of sound absorption and sound speed characteristics of sediments at the Dabob Bay and Keyport Shallow Water ranges operated by the Naval Undersea Warfare Engineering Station using empirical models developed by Hamilton and mean grain size and porosity data measured in samples collected by the authors. Data reported by earlier investigators permit estimates to be made also for sediments at the Nanoose and Jervis Inlet ranges. The purpose is to provide information which can be used in the design and evaluation of acoustic imaging devices which maybe able to ease the problems of locating and recovery of torpedoes which became buried in the sediments. Field and laboratory procedures are described. Also reported are the results of measured sound speeds in a number of the gravity core samples The most common surficial sediment is a soft, saturated silty-clay mud. For such sediments the sound absorption coefficient alpha in dB per meter should be given approximately by alpha = 0.1 where F is the sound frequency in kHz. It is concluded that sound absorption in these sediments, although not small, should not preclude the short range use of an acoustic imaging system operating at moderate frequencies. The possibility and the consequences of the existence of of gassy sediments is discussed.
Download or read book Acoustics of the Seabed as a Poroelastic Medium written by Nicholas P. Chotiros and published by Springer. This book was released on 2017-03-20 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Acoustic Properties of Sediments written by Loyd Hampton and published by . This book was released on 1967 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Sediment Acoustics written by Robert D. Stoll and published by Springer. This book was released on 1989-12-15 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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."
Download or read book Acoustic and Related Properties of the Sea Floor written by Edwin Lee Hamilton and published by . This book was released on 1975 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: The general objectives of this investigation were to determine and study those characteristics of the sea floor that affect sound propagation and the prediction of sonar performance; to support underwater acoustics' experiments and theory by furnishing information on the mass physical properties of sediments and rocks in the form of geoacoustic models of the sea floor; and to develop models of the sea floor which include gradients of sound velocity and attenuation, density, and elastic properties. Specifically, the minor objectives were to revise and review earlier work on the relations between frequency and attenuation of compressional (sound) waves in marine sediments and on the relations between attenuation and sediment porosity. The major objectives were to determine and predict variations of the attenuation of sound waves with depth in the sea floor.
Download or read book Sediment Characterization Using in Situ Measurements of Acoustic Properties written by Justin Thomas Dubin and published by . This book was released on 2018 with total page 238 pages. Available in PDF, EPUB and Kindle. Book excerpt: Three related studies associated with the acoustics of marine sediments were performed and described here. The first study was a direct exploration of the microscopic properties of marine sediment collected in the field. High-resolution images, acquired through scanning electron microscopy, are presented alongside sediment analysis and in situ sound speed data in order to better understand the affect microscopic geometries have on acoustic propagation in naturally occurring marine sediment. This microscopy work is followed by a description of the apparatus, methodology, and results from a field experiment conducted in a shallow water seagrass-bearing environment in which the acoustic properties of both the seagrass canopy and underlying sediment were measured in situ. The results are compared to predictions from several effective medium models to help explain the observed propagation behavior. The final study in this thesis describes acoustic directivity characterization for the compressional wave transducer probes used to collect in situ data presented in the previous studies as well as for a re-designed pair of prototype probes. These laboratory measurements are compared to both analytical and finite element models.
Download or read book Measurement and Correlation of Acoustic Reflection and Sediment Properties Off Panama City Florida written by E. G. McLeroy and published by . This book was released on 1972 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt: Continuous fathometer echo measurements were made along a 1200-mile track in the Gulf of Mexico off Panama City, Florida. Bottom samples were taken at 160 locations in the 3500 square mile test area. The amplitude and length of the echoes at the 160 locations were compared with results of the laboratory measurements of various sediment parameters. The echo parameters are readily correlatable with sediment water content, porosity, and the fraction of silt- and clay-sized particles. The length of the echo is suggested as a good indicator of the grain size fraction. (Author).
Download or read book Acoustical Properties of Laboratory and in Situ Sediments written by P. J. Vidmar and published by . This book was released on 1983 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Deep Sea Sediments written by Anton L. Inderbitzen and published by Springer. This book was released on 1974-06 with total page 520 pages. Available in PDF, EPUB and Kindle. Book excerpt: As part of its continuing program to stimulate superior basic research in the marine environment, the Office of Naval Research, Ocean Science and Technology Division, sponsored a series of closed seminar-workshops in 1972-1973. Each seminar focused upon one re search area of marine geology which is relatively new and in need of a critical evaluation and accelerated support. The subjects areas chosen for the seminars were: 1. natural gases in marine sediments and their mode of distribution, 2. nephelometry and the optical properties of ocean waters, 3. physical and engineering properties of deep-sea sediments, and 4. physics of sound in marine sediments. The objectives of each seminar-workshop were to bring into sharper focus the state-of-the-science within each subject area, to effect some degree of coordination among the investigators working within each of these areas and to provide the Ocean Science and Technology Division guidance for national program support. This volume.contains most of the papers presented at the semi nar on the physical and engineering properties of deep-sea sediments. The seminar was held at Airlie House, Airlie, Virginia on April 24- 27, 1973 and was organized and chaired by A. Inderbitzen. The at tendees were invited from among the leading investigators in this field from both the engineering and scientific disciplines. Each attendee was requested to prepare a paper within his area of spe ciality.
Download or read book The Acoustic Properties of Marine Sediments written by C. McCann and published by . This book was released on 1990 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Physical and Acoustical Properties of Surface Sediment from Venezuela Basin A Data Report written by K. Briggs and published by . This book was released on 1984 with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt: Physical and acoustic properties of surface sediments collected with a 0.25 sq.m box core were measured from 45 stations in the Venezuela Basin. Samples were collected from three locations representing different sedimentary provinces in addition to transects between the locations. Location 1 (15 deg 07'N, 69 deg 22'W) was on the eastern slope of the Beata Ridge in 3950 m water depth. Sediments were pelagic foraminifera ooze. Location 2 (13 deg 45'N, 67 deg 45'W) was in the central Venezuela Basin in 5050 m water depth. Sediments consisted of interbedded turbidite and pelagic sediments. Location 3 (13 deg 30'N, 64 deg 45'W) was on the western flank of the Aves Ridge in 3500 m water depth. Sediments were predominantly hemipelagic in origin. In this report we present the entire data set in table form. Methods of collection and subsequent laboratory and computational analysis are presented in detail. The data presented here will be the subject of more detailed analysis in future publications.
Download or read book Relationships Among Sediment Physical and Acoustic Properties in Siliciclastic and Calcareous Sediments written by and published by . This book was released on 2003 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since the early 1980s, the authors have collected nearly 800 cores at 69 shallow-water sites around the world (12 calcareous and 57 siliciclastic sites). Siliciclastic sites ranged from soft mud through coarse sand and calcareous sites consisted of molluskan shells, shell hash, carbonate reef debris, and calcareous particles formed by chemical precipitation. The cores were carefully collected by divers from shallow water or sub-sampled from box core samples retrieved from deeper waters. For most sediment samples compressional wave speed and attenuation (at 400 kHz) were measured at 1 cm intervals and sediment physical properties (porosity, bulk density, grain density, and grain size distribution) were determined from 2- cm-thick sections from the same core. Data are typically restricted to the upper 30 cm of sediment. Based on the nearly 4500 common data points resulting from core measurements (3922 siliciclastic and 621 calcareous) regressions were determined among sediment physical and acoustic properties.
Download or read book Acoustic and Other Physical Properties of Shallow water Sediments Off San Diego written by E. L. Hamilton and published by . This book was released on 1956* with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Measurement of the Acoustic Properties of Sea floor Sediments from M V Whitethorn written by Peter G. Simpkin and published by . This book was released on 1974 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:
