Download or read book Seismic Traveltime Inversion in Three dimensional Heterogeneous Media written by Christopher Jude Finn and published by . This book was released on 1990 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The measured traveltimes of specular reflection events are inverted to obtain a low spatial frequency, three-dimensional model of the reflector geometry and the compressional wave propagation speed. B-spline functions are used to describe the shapes of the interfaces and the lateral variations in velocity. The inversion is performed by optimizing a maximum likelihood criterion using a Newton based iteration. Model updates are obtained by iterative forward modeling and solution of the linearized equation set derived from the maximum likelihood criterion. In the forward problem, the ray tracing equations are solved as a two point boundary value problem with appropriate internal boundary conditions at velocity discontinuities. Analytic expressions for the Frechet derivatives necessary to obtain the model updates are given. Conventional methods are compared to the traveltime inversion technique using synthetic examples. For a relatively simple earth model containing only moderate lateral velocity variations hyperbolic moveout analysis followed by a Dix inversion produces a biased estimate of the velocity and depth. This is a consequence of the simplifying assumptions of the method. In this case, the more general traveltime analysis provides a better result. This is also true for a more complex earth model containing lateral velocity variations and interfaces with large dips and curvatures where the conventional methods fail badly. Picked traveltimes are used as the data in the inversion although the use of the data semblance or the stack power along the predicted traveltime trajectory is also explored. These criterion are shown to be more nonlinear than the least-squares data residual measure. Thus, it is difficult to converge to a global minimum using these criterion and more accurate initial guesses are necessary. An application of the traveltime inversion technique to a 3D marine data set is presented. In this application the effects of the seismic source and the recording system on the measured traveltimes are estimated. The time delay between the first break and the main pulse of the minimum phase source wavelet and the effect of the ghost reflections from the free surface are compensated for in the prediction of the measured traveltimes
Download or read book Seismic Ray Theory written by V. Cerveny and published by Cambridge University Press. This book was released on 2001-07-02 with total page 723 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive treatment of the seismic ray method; an invaluable advanced textbook and reference volume.
Download or read book Computation of multivalued traveltimes in three dimensional heterogeneous media written by Radu Aurel Coman and published by . This book was released on 2003 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Seismic Traveltime Inversion written by Sergeĭ Vasilʹevich Golʹdin and published by . This book was released on 1986 with total page 392 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Full 3D Seismic Waveform Inversion written by Po Chen and published by Springer. This book was released on 2015-09-10 with total page 543 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book introduces a methodology for solving the seismic inverse problem using purely numerical solutions built on 3D wave equations and which is free of the approximations or simplifications that are common in classical seismic inversion methodologies and therefore applicable to arbitrary 3D geological media and seismic source models. Source codes provided allow readers to experiment with the calculations demonstrated and also explore their own applications.
Download or read book Monitoring the Comprehensive Nuclear Test Ban Treaty Surface Waves written by Anatoli L. Levshin and published by Springer Science & Business Media. This book was released on 2001-09-01 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt: On September 1996, the United Nations General Assembly adopted the Comprehensive Nuclear-Test-Ban Treaty (CTBT), prohibiting nuclear explosions worldwide, in all environments. The treaty calls for a global verification system, including a network of 321 monitoring stations distributed around the globe, a data communications network, an international data center (IDC), and on-site inspections to verify compliance. Seismic methods play the lead role in monitoring the CTBT. This volume concentrates on the measurement and use of surface waves in monitoring the CTBT. Surface waves have three principal applications in CTBT monitoring: to help discriminate nuclear explosions from other sources of seismic energy, to provide mathematical characterizations of the seismic energy that emanates from seismic sources, and to be used as data in inversion for the seismic velocity structure of the crust and uppermost mantle for locating small seismic events regionally. The papers in this volume fall into two general categories: the development and/or application of methods to summarize information in surface waves, and the use of these summaries to advance the art of surface-wave identification, measurement, and source characterization. These papers cut across essentially all of the major applications of surface waves to monitoring the CTBT. This volume therefore provides a general introduction to the state of research in this area and should be useful as a guide for further exploration.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1991 with total page 910 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Three dimensional Tomographic Inversion of Combined Reflection and Refraction Seismic Travel time Data written by James William Douglas Hobro and published by . This book was released on 2000 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Seismic Motion Lithospheric Structures Earthquake and Volcanic Sources written by Yehuda Ben-Zion and published by Birkhäuser. This book was released on 2012-12-06 with total page 369 pages. Available in PDF, EPUB and Kindle. Book excerpt: Geophysicists use seismic signals to image structures in the Earth's interior, to understand the mechanics of earthquake and volcanic sources, and to estimate their associated hazards. Keiiti Aki developed pioneering quantitative methods for extracting useful information from various portions of observed seismograms and applied these methods to many problems in the above fields. This volume honors Aki's contributions with review papers and results from recent applications by his former students and scientific associates pertaining to topics spawned by his work. Discussed subjects include analytical and numerical techniques for calculating dynamic rupture and radiated seismic waves, stochastic models used in engineering seismology, earthquake and volcanic source processes, seismic tomography, properties of lithospheric structures, analysis of scattered waves, and more. The volume will be useful to students and professional geophysicists alike.
Download or read book Full Seismic Waveform Modelling and Inversion written by Andreas Fichtner and published by Springer Science & Business Media. This book was released on 2010-11-16 with total page 352 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent progress in numerical methods and computer science allows us today to simulate the propagation of seismic waves through realistically heterogeneous Earth models with unprecedented accuracy. Full waveform tomography is a tomographic technique that takes advantage of numerical solutions of the elastic wave equation. The accuracy of the numerical solutions and the exploitation of complete waveform information result in tomographic images that are both more realistic and better resolved. This book develops and describes state of the art methodologies covering all aspects of full waveform tomography including methods for the numerical solution of the elastic wave equation, the adjoint method, the design of objective functionals and optimisation schemes. It provides a variety of case studies on all scales from local to global based on a large number of examples involving real data. It is a comprehensive reference on full waveform tomography for advanced students, researchers and professionals.
Download or read book Geophysical Data Analysis Discrete Inverse Theory written by William Menke and published by Academic Press. This book was released on 2012-12-02 with total page 273 pages. Available in PDF, EPUB and Kindle. Book excerpt: Geophysical Data Analysis: Discrete Inverse Theory is an introductory text focusing on discrete inverse theory that is concerned with parameters that either are truly discrete or can be adequately approximated as discrete. Organized into 12 chapters, the book’s opening chapters provide a general background of inverse problems and their corresponding solution, as well as some of the basic concepts from probability theory that are applied throughout the text. Chapters 3-7 discuss the solution of the canonical inverse problem, that is, the linear problem with Gaussian statistics, and discussions on problems that are non-Gaussian and nonlinear are covered in Chapters 8 and 9. Chapters 10-12 present examples of the use of inverse theory and a discussion on the numerical algorithms that must be employed to solve inverse problems on a computer. This book is of value to graduate students and many college seniors in the applied sciences.
Download or read book Inversion of Traveltime Data for Seismic Velocity Structure in Three Dimensions written by Joyce Chee Wu and published by . This book was released on 1977 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Seismic Tomography written by H.M. Iyer and published by Springer Science & Business Media. This book was released on 1993-05-31 with total page 890 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a systematic review of tomographic applications in seismology and the future directions. Theories and case histories are discussed by the international authors, drawing on their own practical experiences with global and local case histories.
Download or read book Seismic Inversion written by Gerard T. Schuster and published by SEG Books. This book was released on 2017-07-01 with total page 377 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book describes the theory and practice of inverting seismic data for the subsurface rock properties of the earth. The primary application is for inverting reflection and/or transmission data from engineering or exploration surveys, but the methods described also can be used for earthquake studies. Seismic Inversion will be of benefit to scientists and advanced students in engineering, earth sciences, and physics. It is desirable that the reader has some familiarity with certain aspects of numerical computation, such as finite-difference solutions to partial differential equations, numerical linear algebra, and the basic physics of wave propagation. For those not familiar with the terminology and methods of seismic exploration, a brief introduction is provided. To truly understand the nuances of seismic inversion, we have to actively practice what we preach (or teach). Therefore, computational labs are provided for most of the chapters, and some field data labs are given as well.
Download or read book Inverse Problem Theory and Methods for Model Parameter Estimation written by Albert Tarantola and published by SIAM. This book was released on 2005-01-01 with total page 349 pages. Available in PDF, EPUB and Kindle. Book excerpt: While the prediction of observations is a forward problem, the use of actual observations to infer the properties of a model is an inverse problem. Inverse problems are difficult because they may not have a unique solution. The description of uncertainties plays a central role in the theory, which is based on probability theory. This book proposes a general approach that is valid for linear as well as for nonlinear problems. The philosophy is essentially probabilistic and allows the reader to understand the basic difficulties appearing in the resolution of inverse problems. The book attempts to explain how a method of acquisition of information can be applied to actual real-world problems, and many of the arguments are heuristic.
Download or read book Three dimensional Inversion of P wave Travel Time Residuals and Other Related Studies at the Upper Michigan Northern Wisconsin Seismic Network written by Mark A. Feighner and published by . This book was released on 1983 with total page 374 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Interpretation of Three Dimensional Seismic Data Seventh Edition written by Alistair R. Brown and published by AAPG. This book was released on 2011-08-20 with total page 664 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hardcover plus DVD
