Download or read book Ultrasonic Physical Modeling of Seismic Wave Propagation from Graben Like Structures written by M. S. Vassiliou and published by . This book was released on 1987 with total page 51 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report describes ultrasonic experiments intended to help clarify the problem of seismic wave propagation in cases where sources are excited in a graben-like structure with significantly different material properties from those of the surrounding propagation medium. Ultrasonic waves are produced using a breaking pencil lead as a source (step unloading of the surface) and a true-displacement conical transducer as a receiver. We have made measurements by exciting the source on the half space (made of fine grained gabbro, with V sub p = 6.2 km/s) and within two graben-like structures: a cylindrical plug graben of 13 mm diameter and 2 mm depth; and a scale model (1 mm = 1 km) of Yucca Flat. In the case of cylindrical graben, the presence of a source region with significantly slower velocities than the surrounding region appears to lead to a more complex signal, with more ringing than would be apparant if there were no such region. The presence of such a source appears to result in a relative amplification of the high frequency part (200-400 KHz) of the signal. If we scale the results so that they correspond to a cylindrical basin roughly the size of Yucca Flat, this means that frequencies analogous to 3-10 s in the Earth appear to be amplified relative to lower frequencies. Experiments on the scale model of Yucca Flat yield, in general, less dramatic results. The loss of symmetry apparently leads to less opportunity for focussing, and amplifications are not as great. Waveforms do not vary as much azimuthally in character or shape as they do in the cylindrical case, nor do they vary as much with source position within the graben.

Download or read book Ultrasonic Physical Modeling of Seismic Wave Propagation from a Graben like Structure written by M. S. Vassiliou and published by . This book was released on 1986 with total page 27 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Ultrasonic Physical Modeling of Seismic Wave Propagation from a Graben Like Structure A Preliminary Report written by M. S. Vassiliou and published by . This book was released on 1986 with total page 33 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ultrasonic experiments help clarify the problem of seismic wave propagation in cases where sources are excited in a region with significantly different properties from those of the surrounding propagation medium. Such a case exists, for example, when nuclear explosions are detonated at Yucca Flat. Ultrasonic waves are produced using a breaking pencil lead as a source (step unloading of the surface), and a true displacement conical transducer as a receiver. Measurements are made setting the source off on the half space (made of fine grained gabbro, with Vp=6.2 km/s), and with a cylindrical graben of 13mm diameter and 2mm depth. The graben was filled with either crystal wax (Vp=2.407) or HPAL3 (an aluminum filled resin with Vp=3.287). Rayleigh waves for frequency 100 KHz in the model are roughly analogous to 20 s in the Earth. The presence of a source region with significantly slower velocities than the surrounding region appears to lead to more complex signal, with more ringing than would be apparent if there were no such source region. The presence of such a source region appears to result in a relative amplification of the high frequency part of the signal. The frequencies analogous to 3 or 4 s in the Earth appear to be amplified relative to lower frequencies. Although the pencil lead source used in this study is not exactly similar to an explosion, this result may still be significant. When the source is set off in the garben in an off center position, a radiation pattern is established, with amplitude varying by a factor of 2 or more. Material effects appear to be accentuated when the source is excited off center.

Download or read book Seismic Physical Modeling Applied in Ultrasonic Nondestructive Testing and Seismic Wave Propagation written by 曾柏諺 and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1988 with total page 964 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.

Download or read book Energy Research Abstracts written by and published by . This book was released on 1987 with total page 532 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Government Reports Announcements Index written by and published by . This book was released on 1988 with total page 1226 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Technical Reports Awareness Circular TRAC written by and published by . This book was released on 1987-05 with total page 764 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Government Reports Annual Index written by and published by . This book was released on 1988 with total page 1080 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Seismic Wave Propagation and Scattering in the Heterogeneous Earth written by Haruo Sato and published by Springer. This book was released on 1998 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt: Focusing on recent developments in the area of seismic wave propagation and scattering, this text combines information from numerous sources to present a coherent introduction to the theory of scattering in acoustic and elastic materials. With the emphasis firmly on the lithosphere, the book includes analyses of observations using the theoretical methods developed. Written for advanced undergraduates and beginning graduates of geophysics and planetary sciences, this is also of interest to civil engineers, seismologists, acoustical engineers, and others interested in wave propagation through inhomogeneous elastic media.

Download or read book Numerical Modeling of Seismic Wave Propagation written by K. R. Kelly and published by SEG Books. This book was released on 1990 with total page 540 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Seismological Research Letters written by and published by . This book was released on 1987 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Numerical Modeling of Seismic Wave Propagation written by Johan O. A. Robertsson and published by SEG Books. This book was released on 2012 with total page 115 pages. Available in PDF, EPUB and Kindle. Book excerpt: The decades following SEG's 1990 volume on numerical modeling showed a step change in the application and use of full wave equation modeling methods enabled by the increase in computational power. Full waveform inversion, reverse time migration, and 3D elastic finite-difference synthetic data generation are examples. A searchable CD is included.

Download or read book Seismic Wave Propagation in Non Homogeneous Elastic Media by Boundary Elements written by George D. Manolis and published by Springer. This book was released on 2016-09-23 with total page 301 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses on the mathematical potential and computational efficiency of the Boundary Element Method (BEM) for modeling seismic wave propagation in either continuous or discrete inhomogeneous elastic/viscoelastic, isotropic/anisotropic media containing multiple cavities, cracks, inclusions and surface topography. BEM models may take into account the entire seismic wave path from the seismic source through the geological deposits all the way up to the local site under consideration. The general presentation of the theoretical basis of elastodynamics for inhomogeneous and heterogeneous continua in the first part is followed by the analytical derivation of fundamental solutions and Green's functions for the governing field equations by the usage of Fourier and Radon transforms. The numerical implementation of the BEM is for antiplane in the second part as well as for plane strain boundary value problems in the third part. Verification studies and parametric analysis appear throughout the book, as do both recent references and seminal ones from the past. Since the background of the authors is in solid mechanics and mathematical physics, the presented BEM formulations are valid for many areas such as civil engineering, geophysics, material science and all others concerning elastic wave propagation through inhomogeneous and heterogeneous media. The material presented in this book is suitable for self-study. The book is written at a level suitable for advanced undergraduates or beginning graduate students in solid mechanics, computational mechanics and fracture mechanics.

Download or read book Seismic Waves in Laterally Inhomogeneous Media Part II written by Ivan Psencik and published by Birkhäuser. This book was released on 2012-12-06 with total page 386 pages. Available in PDF, EPUB and Kindle. Book excerpt: The special issue contains contributions presented at the international workshop Seismic waves in laterally inhomogeneous media IV, which was held at the Castle of Trest, Czech Republic, May 22-27, 1995. The workshop, which was attended by about 100 seismologists from more than 10 countries, was devoted mainly to the current state of theoretical and computational means of study of seismic wave propagation in complex structures. The special issue can be of interest for theoretical, global and explorational seismologists. The first part contains papers dealing with the study and the use of various methods of solving forward and inverse problems in complicated structures. Among other methods, discrete-wave number method, the finite-difference method, the edge-wave supperposition method and the ray method are studied and used. Most papers contained in the second part are related to the ray method. The most important topics are two-point ray tracing, grid calculations of travel times and amplitudes and seismic wave propagation in anisotropic media.

Download or read book Seismic Wave Propagation in Real Media written by and published by . This book was released on 1969 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Seismic Wave Propagation in Stratified Media written by Brian Leslie Norman Kennett and published by . This book was released on 2009 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt: Seismic Wave Propagation in Stratified Media presents a systematic treatment of the interaction of seismic waves with Earth structure. The theoretical development is physically based and is closely tied to the nature of the seismograms observed across a wide range of distance scales - from a few kilometres as in shallow reflection work for geophysical prospecting, to many thousands of kilometres for major earthquakes. A unified framework is presented for all classes of seismic phenomena, for both body waves and surface waves. Since its first publication in 1983 this book has been an important resource for understanding the way in which seismic waves can be understood in terms of reflection and transmission properties of Earth models, and how complete theoretical seismograms can be calculated. The methods allow the development of specific approximations that allow concentration on different seismic arrivals and hence provide a direct tie to seismic observations.