The welcome accorded to the first two editions of this book has been most encouraging. The object of the third edition continues to be to give a brief but "fairly comprehensive survey of the methods of applied geophysics including some of the modern interpretation techniques. The general approach and plan of the previous editions are preserved, but in bringing the book up to date some changes have been made to which I would like to draw the reader's special attention. SI units are strictly adhered to except in six illustrative figures reproduced from older literature and left intact to save some extensive redraughting. Following the recommendation of the International Union of Geodesy and Geophysics, the magnetic field measured in geophysical work is labelled here as flux density (tesla). Consequently, the symbols H, Z and T commonly used in geomagnetic work should stand for flux density. In the Max wellian theory of electromagnetism the symbol H stands, by convention, for a magnetizing force (A m -1) and a discerning reader will at once sense a source of confusion. This source of confusion is avoided in the present edition by B , B and B instead of H, Z and T. The employing the symbols b z t latter ~et is employed for the corresponding magnetizing forces of the earth's field. I hope this notation will gain general acceptance because it so easily dispenses with an ambiguity that otherwise tends to lead to unnecessary confusion of units and dimensions in geomagnetism.

Principles of Geophysics is an essential, comprehensive resource for researchers and students, emphasizing both the physical basis and practical uses of geophysical methods. In addition, it covers the fundamentals of exploration and the global aspects of geophysics. The authors cover geophysics across a broad spectrum--from basic concepts to advanced mathematical formulae--thereby helping readers from diverse backgrounds to understand the structures, processes and applications of geophysics. Worked examples and a detailed index of equations, symbols and mathematical concepts aid in comprehension and make the book an excellent reference. Chapters are organized into topical self-contained units to suit a diverse readership. The chapters proceed from background theory to rigorous analysis, gradually escalating in mathematical complexity. This format enables the reader to develop either a qualitative understanding of only the material and/or to follow the calculations. The text contains over 200 illustrations.

This second edition of Fundamentals of Geophysics has been completely revised and updated, and is the ideal geophysics textbook for undergraduate students of geoscience with an introductory level of knowledge in physics and mathematics. It gives a comprehensive treatment of the fundamental principles of each major branch of geophysics, and presents geophysics within the wider context of plate tectonics, geodynamics and planetary science. Basic principles are explained with the aid of numerous figures and step-by-step mathematical treatments, and important geophysical results are illustrated with examples from the scientific literature. Text-boxes are used for auxiliary explanations and to handle topics of interest for more advanced students. This new edition also includes review questions at the end of each chapter to help assess the reader's understanding of the topics covered and quantitative exercises for more thorough evaluation. Solutions to the exercises and electronic copies of the figures are available at www.cambridge.org/9780521859028.

For a thorough comprehension of the field of geophysics, we need to understand its origins. Basic Geophysics by Enders Robinson and Dean Clark takes us on a journey that demonstrates how the achievements of our predecessors have paved the way for our modern science. From the ancient Greeks through the Enlightenment to the greats of the contemporary age, the reasoning behind basic principles is explored and clarified. With that foundation, several advanced topics are examined, including: the 3D wave equation; ray tracing and seismic modeling; reflection, refraction, and diffraction; and WKBJ migration. The successful integration of the historical narrative alongside practical analysis of relevant principles makes this book an excellent resource for both novices and professionals, and all readers will gain insight and appreciation for the seismic theory that underlies modern exploration seismology.

This combination of textbook and reference manual provides a comprehensive account of gravity and magnetic methods for exploring the subsurface using surface, marine, airborne and satellite measurements. It describes key current topics and techniques, physical properties of rocks and other Earth materials, and digital data analysis methods used to process and interpret anomalies for subsurface information. Each chapter starts with an overview and concludes by listing key concepts to consolidate new learning. An accompanying website presents problem sets and interactive computer-based exercises, providing hands-on experience of processing, modeling and interpreting data. A comprehensive online suite of full-color case histories illustrates the practical utility of modern gravity and magnetic surveys. This is an ideal text for advanced undergraduate and graduate courses and reference text for research academics and professional geophysicists. It is a valuable resource for all those interested in petroleum, engineering, mineral, environmental, geological and archeological exploration of the lithosphere.

As a slag heap, the result of strip mining, creeps closer to his house in the Ohio hills, fifteen-year-old M. C. is torn between trying to get his family away and fighting for the home they love.