This research monograph presents all the branches of geophysics based on natural electromagnetic fields and their associated subjects. Meant for postgraduate and research level courses, it includes research guidance and collection of magnetotelluric data in some parts of Eastern India and their qualitative and quantitative interpretation. Specific topics highlighted include (i) Electrotellurics, (ii) Magnetotellurics, (iii) Geomagnetic Depth Sounding and Magnetometer Array Studies, (iv) Audio Frequency Magnetotellurics and Magnetic Methods, (v) Marine Magnetotelluric and Marine Controlled Source Electromagnetic Methods, (vi) Electrical Conductivity of Rocks and Minerals and (vii) Mathematical Modelling and Some Topics on Inversion needed for Interpretation of Geoelectrical Data.

This volume combines review and solicited contributions, related to scientific studies of Division I of IAGA presented at its Scientific Assembly in Sopron in 2009. The book is aimed at intermediate to advanced readers dealing with the Earth’s magnetic field generation, its historical records in rocks and geological formations - including links to geodynamics and magnetic dating, with magnetic carriers in earth materials, electromagnetic induction and conductivity studies of the Earth interior with environmental applications of rock magnetism and electromagnetism. The aim of the book is to provide an overview of recent advances and future challenges in these particular fields of research.

The report presents a self-contained exposition of ground wave propagation over a smooth inhomogeneous earth model. A factorization procedure is used to obtain an exact solution for a two-dimensional cylindrical model which may have any number of homogeneous sections. It is demonstrated that under most conditions in practice, the solution for the mode conversion coefficients can be simplified to a form which was derived earlier by an application of the compensation theorem. Formulas are given which permit the refinement of earlier approximate calculations if such accuracy is required in future engineering developments such as precise navigation systems. (Author).

The study presents the 3D electromagnetic model of layered isotropic and anisotropic media using an induction logging tool. This tool utilizes the electromagnetic wave frequency domain (EWFD) interface with Maxwell's equations. The study shows the effect of conductivity and depth for determining the electric field among single and multiple-layered formations. An induction logging tool operates deep inside the earth surface to measure earth formations and yields real-time formation parameters related to the layer of the earth as a function of depth. COMSOL Multiphysics software designs the induction logging tool, complex voltages are obtained from the 3D COMSOL model for the different layered formation, and MATLAB calculates attenuation and phase shifts. The induction tool is applied to both normal and horizontal directions in the formation to obtain electric fields and complex voltages. The method has an advantage of operating under complicated scenarios including one-, two- and three-layers without knowing the detailed properties.

Principles of Electromagnetic Methods in Surface Geophysics contains information about the theory of electromagnetic fields in a conducting media. It describes the theoretical and physical principles of the main geophysical methods using electromagnetic fields, including frequency and transient soundings, electromagnetic profiling, and magnetotelluric soundings. Special attention is paid to models and signal processing methods used in modern exploration geophysics for groundwater, mineral and hydrocarbon exploration. Offers an integrated approach to the description of electromagnetic geophysical fields used for surface geophysical surveys Provides a clear introduction to the physical background of electromagnetic methods and their application Rounds off the treatment of the main geophysical methods: gravity, magnetic seismic, electric and electromagnetic methods