Electromagnetism and the Earth's Interior

PrefaceChapter 1. Introductory RemarksChapter 2. Main Magnetic Field of the Earth World's Distribution of the Geomagnetic Field Elements of the Geomagnetic Field Magnetic Charts Spherical Harmonic Analysis of the Main Field Dipole Field Eccentric DipoleChapter 3. Theory of Steady Dynamo Theories of the Origin of the Earth's Magnetism Permanent Magnetization Free Decay of Electric Current Gyromagnetic Effect Rotating Electric Charge Electromagnetic Induction by Magnetic Storms Thermoelectric Effect Hall Effect Compression Effect Rotation of a Massive Body Twisted-Kink Theory Basic Idea of the Dynamo Equations for a Homogeneous Dynamo Physical Discussions Relating to the Homogeneous Dynamo Convection Current and Magnetic Lines of Force Bullard Process Feedback Mechanism Proposed by Bullard Eigen-Value Problem Additional Discussion Inglis Model Visual Aid by Inglis Equations for the Inglis Model Non-Dimensional form of the Equations Steady-State Solution Steady State of a Model of Manageable Size in a Laboratory Inglis Model with the Size of the Earth's Core Backus and Herzenberg Dynamos Lowes and Wilkinson's ExperimentChapter 4. Stability of the Dipole Field Fundamental Equations for Small M.H.D. Disturbances Given to a Conducting Fluid Body M.H.D. Oscillation of a Perfectly Conducting Fluid Sphere Placed in a Uniform Magnetic Field Effect of the Coriolis Force Stability of the Earth's DynamoChapter 5. Theory of Non-Steady Dynamo Finite-Amplitude Oscillation of a Disk Dynamo Oscillation of a System of Disk Dynamo Disk Dynamo with a Heat Engine Time-Dependent Behaviour of the Inglis ModelChapter 6. Geomagnetic Secular Variation Secular Variation as Observed by Instruments Analysis of the Secular Variation Decrease in the Dipole Moment Secular Variation During Historical and Geological Times Reversal of the Geomagnetic Dipole Evidence from Palaeomagnetic Studies Field Intensity During a Reversal Westward Drift of the Geomagnetic Field Non-Drifting Secular Variation Drift of the Eccentric Dipole Fluctuation in the Length of Day and Geomagnetic Secular VariationChapter 7. Theory of Secular Variation Core—Mantle Coupling and the Westward Drift Rigid-Sphere Model Diffusion of Toroidal Field Mechanical Couple Exerted to the Mantle Time-Dependent Core—Mantle Coupling Oscillation of the Quadrupole Field in Relation to the Northward Shift Growth and Decay of Non-Drifting Field Rigid-Rotator Model Poloidal Fields Associated with Uplifting of Toroidal Field by Convective MotionChapter 8. Electromagnetic Induction within the Earth by Daily Variation Analysis of Solar Daily Variation (Sq) Analysis of Lunar Daily Variation (L) Numerical Method for Calculating a Magnetic Potential Method of Graphical Integration Method of Residuals Surface Integral Method for the Analysis of a PotentialChapter 9. Theory of Electromagnetic Induction in a Spherical Body Fundamental Equations in a Non-Uniform Conductor Conductors with Spherical Symmetry Uniform Sphere Model Non-Uniform Sphere Model when σ=σ0ß-l Spherical Shell Use of High-Speed ComputerChapter 10. Electromagnetic Induction by Various Variations Sudden Storm Commencement (s.s.c.) Storm Main Phase (Dst) Geomagnetic Bay Solar Flare Effect (s.f.e.) Auroral Jet Other VariationsChapter 11. Theory of Electromagnetic Induction in an Earth Having a Plane Surface Fundamental Equations Elementary Solutions Elementary Solutions of the First Type Elementary Solutions of the Second Type Indeterminate Case for Induction by a Uniform Field Relation Between External and Internal Parts of the Geomagnetic Field Over a Plane Earth Line of Magnetic Dipoles Over a Uniform Earth—a Two-Dimensional ProblemChapter 12. Theory of Electromagnetic Induction in a Thin Sheet of Conductor General Equations Plane Sheet Fundamental Characteristics of Electromagnetic Induction in a Uniform Plane Sheet Electromagnetic Induction in a Uniform Plane Sheet by a Magnetic Dipole Non-Uniform Plane Sheet Over a Uniform Semi-Infinite Conductor Anisotropic Plane Sheet Over a Uniform Semi-Infinite Conductor Spherical Sheet Uniform Spherical Sheet Non-Uniform or Anisotropic Spherical Sheets Hemispherical Sheet Electromagnetic Coupling Between a Hemispherical Sheet and an Underlying Conductor Hemispherical Ocean and Sq Induction in a Disk Use of Relaxation Method Two-Dimensional Problem Axisymmetric Problem Hole-in-a-Plate Problem Model ExperimentChapter 13. Theory of Electromagnetic Induction in a Cylinder: Two-Dimensional Problems Circular Cylinder Electromagnetic Coupling Between a Circular Cylinder and an Underlying Layer Elliptic Cylinder Small Flattening and Moderate Conductivity Thin Elliptic Cylinder Highly Conducting Elliptic CylinderChapter 14. Shielding Effect of the Mantle and Secular Variation Plane Slab Model Time-Dependent Dipole at the Core—Mantle BoundaryChapter 15. Overall Distribution of the Electrical Conductivity in the Mantle Conductivity Distribution as Inferred from Geomagnetic Variations Arising from External Sources Uniform Core Model Second Approximation of the Conductivity Distribution Results from Secular Variation Overall Distribution of the Conductivity Conduction Mechanism Geophysical Significance of the Conductivity Distribution Temperature Distribution in the Mantle Derived from the Conductivity Distribution Olivine—Spinel Transition in the Upper MantleChapter 16. Electrical Conductivity in the Core Physical State in the Core Geophysical DiscussionsChapter 17. Possible Effect of the Ocean on Geomagnetic Variations Time Constant of an Ocean Observation on a Floating Ice Station Edge Effect at the Margin of an Ocean Observation on IslandsChapter 18. Earth-Currents and Magneto-Tellurics Earth-Current Observation Electric and Magnetic Fields at the Surface of a Uniform Plane Earth Earth-Currents in a Layered Earth Anisotropy of Earth-Currents Magneto-Telluric Method and its Limitations Magneto-Telluric Techniques Comment on the Plane-Wave Assumption Limitations of Magneto-Telluric MethodChapter 19. Conductivity Anomaly in the Crust and Mantle Anomalies of Geomagnetic Variations in Japan Central Japan Anomaly for Geomagnetic Bay and Similar Variation Anomaly of s.s.c. Anomaly of s.f.e. Anomaly of Sq. Anomaly of Dst Possible Cause of the Anomalies of Geomagnetic Variations in Japan Anomalies in Europe Northern Germany Anomaly Göttingen Anomaly Ponza—Capri Anomaly Czechoslovakian, Hungarian and Rumanian Anomalies Anomalies in Canada Alert Anomaly Mould Bay Anomaly Anomalies in U.S.A. Californian coast Anomaly Sierra Anomaly Texas Anomaly Anomalies in Australia Geophysical Significance of the Conductivity Anomalies in the Crust and MantleReferencesAuthor IndexSubject Index