Gravity Interpretation


Book Description

Gravity interpretation involves inversion of data into models, but it is more. Gravity interpretation is used in a “holistic” sense going beyond “inversion”. Inversion is like optimization within certain a priori assumptions, i.e., all anticipated models lie in a limited domain of the a priori errors. No source should exist outside the anticipated model volume, but that is never literally true. Interpretation goes beyond by taking “outside” possibilities into account in the widest sense. Any neglected possibility carries the danger of seriously affecting the interpretation. Gravity interpretation pertains to wider questions such as the shape of the Earth, the nature of the continental and oceanic crust, isostasy, forces and stresses, geol- ical structure, nding useful resources, climate change, etc. Interpretation is often used synonymously with modelling and inversion of observations toward models. Interpretation places the inversion results into the wider geological or economic context and into the framework of science and humanity. Models play a central role in science. They are images of phenomena of the physical world, for example, scale images or metaphors, enabling the human mind to describe observations and re- tionships by abstract mathematical means. Models served orientation and survival in a complex, partly invisible physical and social environment.




Gravity and Magnetic Exploration


Book Description

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.




Acquisition and Analysis of Terrestrial Gravity Data


Book Description

A one-stop manual for graduate students and professionals, combining introductory gravity survey procedures with full explanations of analysis techniques.







The Utility of Regional Gravity and Magnetic Anomaly Maps


Book Description

The subjects of the papers that make up the volume vary from the preparation of national maps to examples of the many uses of regional maps. The anomalities that are discussed range in areal dimension from hundreds of kilometers to tons of meters. The majority of the papers illustrate the utility of the maps in mapping structures and lithologic variations wirhin the continenetal crust, the configuration of the crystalline basements rocks, zones of crustal weakness, distribution of extrusive and intrusive igneous rocks and the geometry of sedimentary basins. Most cases are drawn from the United States and Canada, but examples from Europe, Africa, South America and Asia are included.




Practical and Theoretical Aspects of Geological Interpretation of Gravitational, Magnetic and Electric Fields


Book Description

This volume offers an overview of the state-of-the-art theoretical and practical approaches currently used for geophysical data interpretation. It includes new methods and techniques for solving data processing problems, and an analysis of geopotential fields by international researchers. It discusses topics such as: 1. Theoretical issues of interpretation of gravitational, magnetic and electric fields, including general methods of interpreting potential fields and other geophysical data. 2. Modern algorithms and computer technologies for interpretating geophysical fields. 3. The study of Earth deep structure using terrestrial and satellite potential field anomalies. 4. Geological interpretation of gravitational, magnetic and electric fields. This proceedings book is of interest to all geophysical researchers.




Applied Geophysics


Book Description

This is the completely revised and updated version of the popular and highly regarded textbook, Applied Geophysics. It describes the physical methods involved in exploration for hydrocarbons and minerals, which include gravity, magnetic, seismic, electrical, electromagnetic, radioactivity, and well-logging methods. All aspects of these methods are described, including basic theory, field equipment, techniques of data acquisition, data processing and interpretation, with the objective of locating commercial deposits of minerals, oil, and gas and determining their extent. In the fourteen years or so since the first edition of Applied Geophysics, many changes have taken place in this field, mainly as the result of new techniques, better instrumentation, and increased use of computers in the field and in the interpretation of data. The authors describe these changes in considerable detail, including improved methods of solving the inverse problem, specialized seismic methods, magnetotellurics as a practical exploration method, time-domain electromagnetic methods, increased use of gamma-ray spectrometers, and improved well-logging methods and interpretation.




Analysis of the Gravity Field


Book Description

This textbook presents a comprehensive treatment of the theory and implementation of inverse methods in the analysis and interpretation of Earth’s gravity field. By restricting their consideration to a local rather than global level, the authors focus on the use of observations and data that are more sensitive to local mass anomalies. All necessary theoretical aspects are reformulated in terms of a Euclidean framework so that less complex tools from mathematical analysis can be utilized. Divided into three parts, the text begins with a review of basic mathematical properties of gravitation, computing gravity from mass distributions, and relevant methods from Fourier analysis. In the second part of the text, the Earth’s gravity field and its properties are introduced, and the preprocessing and processing of gravity data are explored. Finally, elementary inverse theory is discussed, after which the general inversion problem is considered via application of both the Tikhonov deterministic approach and a stochastic MCMC model. Throughout, examples and exercises are provided to both clarify material and to illustrate real-word applications for readers. Analysis of the Gravity Field: Direct and Inverse Problems is carefully written to be accessible to both mathematicians and geophysicists without sacrificing mathematical rigor. Readers should have a familiarity with the basics of mathematical analysis, as well as some knowledge of statistics and probability theory. Detailed proofs of more advanced results are relegated to appendices so that readers can concentrate on solution algorithms.




Potential Theory in Gravity and Magnetic Applications


Book Description

This text bridges the gap between the classic texts on potential theory and modern books on applied geophysics. It opens with an introduction to potential theory, emphasising those aspects particularly important to earth scientists, such as Laplace's equation, Newtonian potential, magnetic and electrostatic fields, and conduction of heat. The theory is then applied to the interpretation of gravity and magnetic anomalies, drawing on examples from modern geophysical literature. Topics explored include regional and global fields, forward modeling, inverse methods, depth-to-source estimation, ideal bodies, analytical continuation, and spectral analysis. The book includes numerous exercises and a variety of computer subroutines written in FORTRAN. Graduate students and researchers in geophysics will find this book essential.




Advanced Methods for Interpreting Geological and Geophysical Data


Book Description

The introduction and application of advanced geological and geophysical methods can solve many problems related to geoscience. This Research Topic gives a thorough treatment of the interpretation of geological and geophysical data through advanced techniques and integrated approaches. It aims to create a more reliable integration of various geological and geophysical data in an exploration and new findings context weighing the strengths and limitations of the various methods in order to develop geophysical and geological models. It will also focus on the interpretation techniques for evaluating structural and sedimentological (stratigraphical) processes with applications within resource exploration, geohazards, seismology, seabed ecology and global climate.