Chapter 1. General Introduction
1.1 Introduction
1.2 Preliminaries on Electromagnetic Waves and Their Application in Geophysical Investigation
1.3 Geomagnetic Field
1.3.1 Magnetic Field of Internal Origin
1.3.1.1 Dipole Field of Internal Origin
1.3.1.2 Nondipole Field of Internal Origin
1.3.1.3 Inclination and Declination of the Magnetic Field
1.3.2 Nondipole Time Varying Magnetic Field of External Origin
1.4 Solar Radiation
1.5 Solar Energy
1.6 Sun Spot Cycle
1.7 Solar Quiet Day (Sa) Variations
1.8 L. Variations
1.9 Equatorial Electrojet (EEJ) and Polar Electrojet (PEJ)
1.10 Solar Flare Effects (SFE)
1.11 Magnetic Storms and Substorms
1.12 D, Dst, Ds Variations
1.13 Bay Type Variations
1.14 Interaction Between the Sun and the Earth
1.15 Magnetosphere
1.16 Cosmic Rays
1.17 Van Allen Radiation Belt
1.18 Ionosphere
1.19 Ring Current
1.20 Magnetotail
1.21 Geomagnetic Field Variations
1.22 Classifications and Causes of the Different Pulsations and Micropulsations
1.22.1 Classification by Jacobs and Sinno (1960)
1.22.2 Classification by Madam Troitskaya (1962)
1.22.3 Classification by Benioff (1960)
1.22.4 Classification by Tepley and Wentworth (1962)
1.22.5 Classification by Vladimirov and Kleimenova (1962)
1.23 High Frequency Natural Electromagnetic Signals, Sferics
1.24 Earth's Natural Electromagnetic Fields as a Subject
1.24.1 Electrotelluric Method (T)
1.24.2 Magnetotelluric Methods (MT)
1.24.3 Geomagnetic Depth Sounding (GDS)
1.24.4 Magnetometer Array Studies (MA)
1.24.5 Magnetovariational Sounding (MVS)
1.24.6 Audiofrequency Magnetotelluric Method (AMT)
1.24.7 Sea Floor Magnetotelluric Method (SFMT)
1.24.8 Marine Magnetotellurics (MMT)
1.24.9 Audiofrequency Magnetic Method (AFMAG)
1.25 Controlled Sources
1.25.1 Controlled Source Audiofrequency Magnetotellurics (CSAMT)
1.25.2 Controlled Source Marine Electromagnetics (CSEM)
1.25.3 Long Offset Electromagnetic Transient (LOTEM)
1.25.4 Radio Magnetotellurics (RMT)
1.26 Coverage of This Book
1.27 References
Chapter 2. Electrical Conduction Through Rocks
2.1 Introduction
2.2 Electrical Conductivity
2.2.1 Expression of Electrical Conductivity for an Homogeneous and Isotropic Medium due to a Point Source of Current
2.2.2 Specific Resistivity or Conductivity
2.2.3 Ohm's Law
2.3 Electrical Permittivity and Displacement Current
2.3.1 Dielectric Constant
2.3.2 Electric Displacement and Displacement Vector D
2.3.3 Tensor Electrical Permittivity
2.4 Magnetic Induction and Magnetic Permeability
2.4.1 Magnetic Induction
2.4.2 Magnetic Permeability
2.5 Principal Methods of Electrical Conduction
2.5.1 Electronic Conduction (Conduction Through Metals)
2.5.2 Conduction of Current Through Semiconductors
2.5.3 Conduction of Current Through Solid Electrolytes
2.5.4 Conduction of Current Through Electrical Displacement
2.5.5 Electrolytic or Ionic Conduction
2.6 Factors Which Control the Electrical Conductivity of the Earth
2.6.1 Porosity of Rocks
2.6.2 Conductivity of Pore Fluids
2.6.3 Size and Shape of Pore Spaces
2.6.4 Conductivity of Mineral Inclusions
2.6.5 Size and Shape of Mineral Grains
2.6.6 Temperature
2.6.7 Frequency of Excitation Current
2.6.8 Ductility and Degree of Partial Melt in Rocks
2.6.9 Electrical Conductivity of Different Types of Rocks
2.6.10 Chemical Activity and Oxygen Fugacity
2.6.11 Dependence of Electrical Conductivity on Pressure
2.6.12 Dependence of Electrical Conductivity on Volatiles
2.6.13 Major Geological Zones of Weaknesses
2.7 Piejoelectric Effect
2.8 Hall Effect
2.9 Maxwells Geoelectrical Conductivity Model
2.9.1 Soft Rock
2.9.2 Hard Rock
2.9.3 Ellipsoidal Grains
2.9.4 Alternating Current Conduction
2.10 Resisitivities of Metallic Rocks and Minerals
2.11 Semiconducting Minerals
2.12 Order of Electrical Conductivity of Some Common Metallic Ores
2.13 Some Common Geological Good and Bad Conductors
2.14 References
Chapter 3. Signal Processing
3.1 Introduction
3.2 Selection of Block Size
3.3 Manual Editing of Time Series
3.4 Moving Average Algorithm
3.5 Trend Elimination
3.6 Fourier Series
3.7 Complex Fourier Series
3.8 Fourier Series for Discrete Time Period Signal
3.9 Integral Transforms
3.10 Fourier Transforms
3.11 Sinc Function
3.12 Two Dimensional Fourier Transform
3.13 Aperiodic Function and Fourier Integral
3.14 Discrete Fourier Transform
3.15 Fast Fourier Transform
3.16 Dirac Delta Function
3.17 Shanons Sampling Theorem
3.18 Linear Filter
3.19 Pulse Response of a Linear Filter
3.20 Convolution
3.21 Z. Transform
3.22 Filters and Windows
3.23 Cross Correlation and Autocorrelation
3.23.1 Cross Correlation
3.23.2 Autocorrelation
3.23.3 Properties of Auto and Cross Correlation
3.24 Autopower and Cross Power Spectrum
3.24.1 Energy Density Spectrum of a Periodic Signal
3.24.2 Power Density Spectrum of a Periodic Signal
3.24.3 Auto Power Spectra
3.24.4 Cross Power Spectra
3.25 Noise
3.26 Robust Processing
3.26.1 Introduction
3.26.2 Outliers
3.26.3 Breakdown Point
3.26.4 Median
3.26.5 Norm
3.26.6 Nongaussian Distribution
3.26.7 Seigel's Repeated Median Estimator
3.26.8 M-Estimator
3.26.9 Field Results
3.27 References
Chapter 4. Electrotellurics
4.1 Introduction
4.2 Basics of Electrotellurics
4.3 Comparison of Electrotelluric and Magnetotelluric Frequencies
4.4 Nature of Telluric Field
4.5 Electrotelluric Method
4.6 Potential Measuring Probes
4.6.1 Electrode Potential
4.6.2 Non Polarisable Electrodes
4.7 Field Recording
4.8 Relative Ellipse
4.8.1 Interconnection Between Base and Mobile Station Vectors
4.8.2 Time Domain Analysis
4.8.3 Electrotelluric Data Analysis
4.9 Triangle Method
4.10 Polygon Method
4.11 Discussion
4.12 Amplitude Ratio Method
4.13 Album of Theoretical Electrotelluric Profile Curves
4.13.1 Telluric Field over a Vertical Fault
4.13.2 Telluric Field over a Basement Asymmetric Anticlinal Structure
4.13.3 Telluric Field over Horst Type of Structure
4.13.4 Telluric Field over a Graben Type of Structure
4.13.5 Telluric Field and its Gradient over a Step Fault
4.14 Analytical Continuation of Telluric Field Data
4.15 Absolute Ellipse Method
4.15.1 Absolute Ellipses
4.15.2 Field Plotting of Absolute Ellipse
4.15.3 Model Tank Experiment for Generation of Absolute Ellipse
4.15.4 Model Tank Generated Absolute Ellipse and the Variation of the Ellipse Parameter due to Simulated Geological Inho
