Electromagnetic exploration is one of the earliest and most widely used geophysical exploration techniques. Electromagnetic methods, such as magnetotelluric (MT), audio magnetotelluric (AMT), transient electromagnetic method (TEM), and controlled source electromagnetic method (CSEM), have made a great contribution to industrialization and urbanization by discovering underground deposits of various resources. Driven by the latest progress in electronics and intelligent algorithms, electromagnetic exploration is developing at a high speed. Many challenges faced by traditional geophysical methods are now solvable. Emerging sensing technology and signal processing technology greatly improves the accuracy of electromagnetic methods in many applications. At the same time, such technologies promoted the development of new geophysical theories and methods.

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.

Foundations of Geophysical Electromagnetic Theory and Methods, Second Edition, builds on the strength of the first edition to offer a systematic exposition of geophysical electromagnetic theory and methods. This new edition highlights progress made over the last decade, with a special focus on recent advances in marine and airborne electromagnetic methods. Also included are recent case histories on practical applications in tectonic studies, mineral exploration, environmental studies and off-shore hydrocarbon exploration. The book is ideal for geoscientists working in all areas of geophysics, including exploration geophysics and applied physics, as well as graduate students and researchers working in the field of electromagnetic theory and methods. - Presents theoretical and methodological foundations of geophysical field theory - Synthesizes fundamental theory and the most recent achievements of electromagnetic (EM) geophysical methods in the framework of a unified systematic exposition - Offers a unique breadth and completeness in providing a general picture of the current state-of-the-art in EM geophysical technology - Discusses practical aspects of EM exploration for mineral and energy resources

This book deals primarily with the aspects of advances in near surface geophysical data modeling, different interpretation techniques, new ideas and an integrated study to delineate the subsurface structures. It also involves the practical application of different geophysical methods to delineate the subsurface structures associated with mineral, groundwater exploration, subsurface contamination, hot springs, coal fire etc. This book is specifically aimed with the state-of-art information regarding research advances and new developments in these areas of study, coupled to extensive modeling and field investigations obtained from around the world. It is extremely enlightening for the research workers, scientists, faculty members and students, in Applied Geophysics, Near Surface Geophysics, Potential Field, Electrical and Electromagnetic Methods, Mathematical Modeling Techniques in Earth Sciences, as well as Environmental Geophysics.

In this book the author presents the state-of-the-art electromagnetic (EM)theories and methods employed in EM geophysical exploration.The book brings together the fundamental theory of EM fields and the practicalaspects of EM exploration for mineral and energy resources.This text is unique in its breadth and completeness in providing anoverview of EM geophysical exploration technology. The book is divided into four parts covering the foundations of EMfield theory and its applications, and emerging geophysical methods.Part I is an introduction to the field theory required for baselineunderstanding. Part II is an overview of all the basic elements ofgeophysical EM theory, from Maxwell's fundamental equations to modernmethods of modeling the EM field in complex 3-D geoelectrical formations. Part III deals with the regularized solution of ill-posedinverse electromagnetic problems, the multidimensional migration and imaging ofelectromagnetic data, and general interpretation techniques. Part IV describes major geophysical electromagnetic methods—direct current (DC), induced polarization (IP), magnetotelluric(MT), and controlled-source electromagnetic (CSEM) methods—and covers different applications of EM methods in exploration geophysics, includingminerals and HC exploration, environmental study, and crustal study. - Presents theoretical and methodological findings, as well as examples of applications of recently developed algorithms and software in solving practical problems - Describes the practical importance of electromagnetic data through enabling discussions on a construction of a closed technological cycle, processing, analysis and three-dimensional interpretation - Updates current findings in the field, especially with MT, magnetovariational and seismo-electrical methods and the practice of 3D interpretations

The magnetotelluric method is a technique for imaging the electrical conductivity and structure of the Earth, from the near surface down to the 410 km transition zone and beyond. This book forms the first comprehensive overview of magnetotellurics, from the salient physics and its mathematical representation to practical implementation in the field, data processing, modeling and geological interpretation. Electromagnetic induction in 1-D, 2-D and 3-D media is explored, building from first principles, and with thorough coverage of the practical techniques of time series processing, distortion, numerical modeling and inversion. The fundamental principles are illustrated with a series of case histories describing geological applications. Technical issues, instrumentation and field practices are described for both land and marine surveys. This book provides a rigorous introduction to magnetotellurics for academic researchers and advanced students, and will be of interest to industrial practitioners and geoscientists wanting to incorporate rock conductivity into their interpretations.

The propagation of waves along and across the boundary between two media with different characteristic velocities is much more complicated when the source is on or near the boundary than when it is far away and the incident waves are plane. Examples of waves generated by localized sources near a boundary are the electromagnetic waves from the currents in a dipole on the surface of the earth and the seismic waves from a slip event in a fault in the earth's crust like the San Andreas fault in California. Both involve a type of surface wave that is called a lateral wave in electro magnetics and a head wave in seismology. Since the two are analogous and the latter is more easily visualized, it is conveniently used here to introduce and describe this important type of surface wave using the data of Y. Ben Zion and P. Malin ("San Andreas Fault Zone Head Waves Near Parkfield, CA," Science 251, 1592-1594, 29 March 1991).

An introduction to the theory and practical application of CSEM methods to explore whether subsurface structures contain hydrocarbons.

Active geophysical monitoring is an important new method for studying time-evolving structures and states in the tectonically active Earth's lithosphere. It is based on repeated time-lapse observations and interpretation of rock-induced changes in geophysical fields periodically excited by controlled sources. In this book, the results of strategic systematic development and the application of new technologies for active geophysical monitoring are presented. The authors demonstrate that active monitoring may drastically change solid Earth geophysics, through the acquisition of substantially new information, based on high accuracy and real-time observations. Active monitoring also provides new means for disaster mitigation, in conjunction with substantial international and interdisciplinary cooperation. - Introduction of a new concept - Most experienced authors in the field - Comprehensiveness