Surface waves form the longest and strongest portion of a seismic record excited by explosions and shallow earthquakes. Traversing areas with diverse geologic structures, they 'absorb' information on the properties of these areas which is best retlected in dispersion, the dependence of velocity on frequency. The other prop erties of these waves - polarization, frequency content, attenuation, azimuthal variation of the amplitude and phase - arc also controlled by the medium between the source and the recording station; some of these are affected by the properties of the source itself and by the conditions around it. In recent years surface wave seismology has become an indispensable part of seismological practice. The maximum amplitude in the surface wave train of virtually every earthquake or major explosion is being measured and used by all national and international seismological surveys in the determination of the most important energy parameter of a seismic source, namely, the magnitude M,. The relationship between M, and the body wave magnitude fI1t, is routinely employed in identification of underground nuclear explosions. Surface waves of hundreds of earthquakes recorded every year are being analysed to estimate the seismic moment tensor of earthquake sources, to determine the periods of free oscillations of the Earth, to construct regional dispersion curves from which in turn the crustal and upper mantle structure in various areas is derived, and to evaluate the dissipative parameters of the mantle material.

The past few decades have witnessed the growth of the Earth Sciences in the pursuit of knowledge and understanding of the planet that we live on. This development addresses the challenging endeavor to enrich human lives with the bounties of Nature as well as to preserve the planet for the generations to come. Solid Earth Geophysics aspires to define and quantify the internal structure and processes of the Earth in terms of the principles of physics and forms the intrinsic framework, which other allied disciplines utilize for more specific investigations. The first edition of the Encyclopedia of Solid Earth Geophysics was published in 1989 by Van Nostrand Reinhold publishing company. More than two decades later, this new volume, edited by Prof. Harsh K. Gupta, represents a thoroughly revised and expanded reference work. It brings together more than 200 articles covering established and new concepts of Geophysics across the various sub-disciplines such as Gravity, Geodesy, Geomagnetism, Seismology, Seismics, Deep Earth Processes, Plate Tectonics, Thermal Domains, Computational Methods, etc. in a systematic and consistent format and standard. It is an authoritative and current reference source with extraordinary width of scope. It draws its unique strength from the expert contributions of editors and authors across the globe. It is designed to serve as a valuable and cherished source of information for current and future generations of professionals.

Seismic waves – generated both by natural earthquakes and by man-made sources – have produced an enormous amount of information about the Earth's interior. In classical seismology, the Earth is modeled as a sequence of uniform horizontal layers (or sperical shells) having different elastic properties and one determines these properties from travel times and dispersion of seismic waves. The Earth, however, is not made of horizontally uniform layers, and classic seismic methods can take large-scale inhomogeneities into account. Smaller-scale irregularities, on the other hand, require other methods. Observations of continuous wave trains that follow classic direct S waves, known as coda waves, have shown that there are heterogeneities of random size scattered randomly throughout the layers of the classic seismic model. This book focuses on recent developments in the area of seismic wave propagation and scattering through the randomly heterogeneous structure of the Earth, with emphasis on the lithosphere. The presentation combines information from many sources to present a coherent introduction to the theory of scattering in acoustic and elastic materials and includes analyses of observations using the theoretical methods developed.

Methods in Computational Physics, Volume 11: Seismology: Surface Waves and Earth Oscillations is a five-chapter text that deals with the computational analysis of surface waves and the eigenvibrations of the Earth. Chapter 1 describes the advances in the numerical modeling of geological structures where the appropriate partial differential equations with boundary conditions for heterogeneous materials are solved using an intricate finite difference scheme. Chapter 2 presents the computer techniques of processing seismograms to obtain information on the dispersion of seismic surface waves, while Chapter 3 explains the fast algorithms for computation of eigenvalues in surface wave and terrestrial eigenvibration problems. Chapter 4 presents a competing method, much used in structural engineering and soil mechanics. Chapter 5 is devoted to the propagation of surface waves in layered media, which indicate that density and elasticity vary only in the vertical direction. This chapter also provides the fundamentals and numerical aspects of the theory of seismic surface waves. This book is an invaluable source for seismologists, earthquake engineers, and graduate students.

The efficient mining of hard coal in deep coal mines using highly mechanized longwall techniques requires information on the geological structure ahead of the operating face. Even minor tectonic faults with throws of only a few metres mean a loss in productivity, as they present severe working problems for underground mining equipment. Because investment costs to install a mechanized face are high, "insurance" in the form of spare capacity by both machine shifts or spare faces is uneconomic. Thus, to reduce mining costs it is essential to delineate the geology prior to mining. Today, the only effective geophysical tool to detect and to map minor faults in front of the coal cutter is in-seam seismics using channel, or so called seam waves. The techniques are well established and successfully applied for more than two decades. In-Seam Seismics covers the entire range of elementary and advanced topics in mathematics, physics and data processing of dispersive channel waves. The results of analogue and numerical modelling provide a thorough understanding of transmission, reflection, recording and interpretation of seam waves and coal seam disturbances. Fire damp proof instrumentation, target orientated underground layouts, processing and interpretation of real data impart the state-of-the-art of in-seam seismics. Selected and well-rounded case histories complete the presentation of in-seam seismics. They can help the mining engineer to come to a decision to plan and to apply in-seam seismics in case of underground mining problems. A clear text, only formulae which are necessary, many carefully designed figures, an extended list of references and a lucid index make it easy for the reader to get acquainted with seam waves or to promote the technique of in-seam seismics.

An Introduction to Seismology, Earthquakes and Earth Structures is an introduction to seismology and its role in the earth sciences, and is written for advanced undergraduate and beginning graduate students. The fundamentals of seismic wave propagation are developed using a physical approach and then applied to show how refraction, reflection, and teleseismic techniques are used to study the structure and thus the composition and evolution of the earth. The book shows how seismic waves are used to study earthquakes and are integrated with other data to investigate the plate tectonic processes that cause earthquakes. Figures, examples, problems, and computer exercises teach students about seismology in a creative and intuitive manner. Necessary mathematical tools including vector and tensor analysis, matrix algebra, Fourier analysis, statistics of errors, signal processing, and data inversion are introduced with many relevant examples. The text also addresses the fundamentals of seismometry and applications of seismology to societal issues. Special attention is paid to help students visualize connections between different topics and view seismology as an integrated science. An Introduction to Seismology, Earthquakes, and Earth Structure gives an excellent overview for students of geophysics and tectonics, and provides a strong foundation for further studies in seismology. Multidisciplinary examples throughout the text - catering to students in varied disciplines (geology, mineralogy, petrology, physics, etc.). Most up to date book on the market - includes recent seismic events such as the 1999 Earthquakes in Turkey, Greece, and Taiwan). Chapter outlines - each chapter begins with an outline and a list of learning objectives to help students focus and study. Essential math review - an entire section reviews the essential math needed to understand seismology. This can be covered in class or left to students to review as needed. End of chapter problem sets - homework problems that cover the material presented in the chapter. Solutions to all odd numbered problem sets are listed in the back so that students can track their progress. Extensive References - classic references and more current references are listed at the end of each chapter. A set of instructor's resources containing downloadable versions of all the figures in the book, errata and answers to homework problems is available at: http://levee.wustl.edu/seismology/book/. Also available on this website are PowerPoint lecture slides corresponding to the first 5 chapters of the book.

The special issue contains contributions presented at the international workshop Seismic waves in laterally inhomo- geneous 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.