Geomagnetism

by Basavaiah, Nathani

• ISBN13: 9789400704022
• ISBN10: 940070402X
• Format: Hardcover
• Copyright: 2011-03-15
• Publisher: Springer Verlag

Summary

With the awareness that the Earth has a magnetic field, its mathematical description, discovery of remanent magnetisation in rocks and discovery of the periodic reversals of the geomagnetic field polarity, geomagnetism within geophysics became an interesting field of study. This is primarily due to advances in measurement technology and improved understanding of the magnetic field and its fluctuations in the geospace. Several important aspects of solid Earth geomagnetism are elaborated in the book. The first six chapters cover the basics of magnetism, magnetic minerals, biomagnetics, instrumentation and the behavior of geomagnetic field, while the rest of the book is devoted to practical applications with carefully selected examples and illustrations. Well-written and easy to read, the book vividly describes modern techniques in the subject matter covered, adequately supported by graphical explanations for complex mathematical concepts.

Author Biography

Dr. Nathani Basavaiah is a well known geophysicist in India with significant contributions in the field of Environmental Magnetism. His pioneering works on satellite-based geopotential field anomalies, applied rock magnetism as well as environmental magnetism, brought him many laurels including the British Council Fellowship (1994-95), European Research Fellowship (1999) and Alexander von Humboldt Research Fellowship (1998-2000). He is a visiting scientist at the University of Tbingen and also worked at the GeoForschungsZentrum, Potsdam, Germany. He is currently engaged in studies on climate change, environmental pollution and palaeoclimate reconstruction. His studies are based on multi-proxy evidences from sediment cores from lakes, deserts, loess, and offshore zones. He has established a well-equipped state-of-the-art Environmental Magnetism Laboratory and trained many students and scientists in this modern technology. Dr. Basavaiah has published more than 45 scientific publications and edited a special volume on 'Environmental Magnetism and Palaeomonsoons' prior to writing this textbook. At present, he is Professor and Head of the Environmental Magnetism Group at the Indian Institute of Geomagnetism (IIG), India.

Table of Contents

Foreword	p. v
Preface	p. vii
Abbreviations	p. xv
The Historical Development of (Geo)Magnetism	p. 1
Global Scene	p. 1
Fundamental Similarity between Electricity and Magnetism	p. 10
Historical Perspective: National Scene against Global Backdrop	p. 14
Geomagnetic Field Elements and Their Measurements	p. 16
Internal Magnetic Field	p. 24
Interior of the Earth and Physical Properties	p. 25
Earth Structure and Its Major Divisions	p. 31
Magnetism in Matter and Magnetic Properties	p. 37
Curie and Neel Temperature	p. 42
Rock Forming Magnetic Minerals and Rock Magnetism	p. 43
Hysteresis Loop	p. 58
Magnetic Materials, Domain States and Grain Sizes	p. 59
Genesis of Earth's Magnetic Field and Its Dynamo Effect	p. 66
Wegener and Continental Drift	p. 69
Palaeomagnetism: An Indirect Measurement of Past Geomagnetic Field	p. 71
Mechanism of Magnetic Banding	p. 76
Plate Tectonics and Seismotectonics	p. 79
Magnetic Field that Extends into Space	p. 87
Structure of the Earth's Atmosphere: Traditional View	p. 89
Structure of the Sun: Association of Sunspots with Terrestrial Phenomena	p. 94
Structure of Magnetosphere	p. 105
Sources of Electric Fields	p. 107
Radio Waves: Scintillation	p. 110
Technique of Magnetic Measurements	p. 115
Magnetometery for Geomagnetic Observatories	p. 117
Magnetic Survey Instruments: Fluxgate and Induction Magnetometers	p. 125
Laboratory Magnetic Instruments	p. 131
Magnetic Observatories and Data Analysis	p. 142
Measurement and Data	p. 146
Geomagnetism and Secular Variation	p. 150
Causes of Geomagnetic Field Variation: External Origin	p. 154
Equatorial Enhancement and Geomagnetic Field Variations	p. 159
Geomagnetic Storms and the Magnetosphere	p. 167
Solid Earth Geomagnetism	p. 174
Geopotential Field Anomaly Studies	p. 177
Satellite Measurements of Earth's Gravity Field	p. 179
Satellite Measurements of the Earth's Magnetic Field	p. 187
Air-borne Magnetic Surveys	p. 199
National Ground Magnetic Surveys	p. 208
Ground Magnetic Surveys	p. 210
Electromagnetic (EM) Induction Methods	p. 222
Basic Method of EM Induction	p. 223
Geomagnetic Depth Sounding (GDS)	p. 226
Methodology, Objectives of GDS Technique	p. 226
Acquisition, Analysis and Presentation of GDS Data	p. 227
Data Processing Techniques	p. 228
GDS Field Surveys	p. 230
Magnetic Variation Mapping Examples	p. 231
Ocean Bottom Magnetometer Studies	p. 235
OBM Field Examples	p. 235
Magnetotelluric Surveys	p. 236
Methodology, Data Acquisition and Time Series Processing	p. 237
Principle of MT Method and Its Utility	p. 241
Applications of MT in Geophysical Prospecting	p. 242
Earthquakes: Causatives and Measurements	p. 249
Major Earthquakes of the World and India	p. 252
Himalayan Tectonics and Its Effect on Peninsula	p. 254
Seismic Zonation Maps and Seimic Hazards	p. 259
Geophysical Studies in Seismically Active Regions	p. 261
Co-Seismic Investigations-Magnetic and Electrical Rock Properties	p. 264
Predicting Earthquakes	p. 265
Earthquake Precursory Changes	p. 266
Earthquake Precursory Case Histories	p. 268
Palaeosiesmology: Quasi-Empirical Earthquake Prediction Technique	p. 274
GPS Measurements and Geodynamics	p. 277
Observational Procedure	p. 279
Methodology, Data Acquisition and Analysis	p. 280
GPS: Repeat Campaigns, Permanent Sites and Case Studies	p. 282
Experimental Geomagnetism	p. 291
Palaeomagnetism and Geomagnetic Field in Geological Past	p. 292
Palaeolatitude, Pole Position, Apparent Polar Wander Path	p. 304
Magnetochronology	p. 309
Implications of Palaeomagnetic Results	p. 316
Environmental Geomagnetism	p. 321
Environmental Geomagnetism vs. Palaeomagnetism	p. 322
Environmental Magnetism: Objectives and Evolution	p. 323
Primary Magnetic Measurements-Magnetic Properties	p. 334
Secondary Magnetic Parameters: Interparametric Ratios	p. 348
Magnetic Studies, Complex Issues	p. 351
Environmental Magnetism-Its Application to the Indian Depositional Settings	p. 354
Magnetic Susceptibility and Depositional Environments	p. 356
Magnetomineralogical S-ratio and Palaeoclimate in Sediments	p. 373
Future Studies	p. 376
Upper Atmosphere Studies	p. 387
Space Weather Effects	p. 398
Ionospheric Electrodynamics: Short Period Fluctuations	p. 406
Equatorial-Latitude Electrodynamical Coupling and Atmospheric Structure	p. 414
Antarctic Magnetic Data	p. 419
Usefulness of Geomagnetic Research	p. 423
Observatories and Data Analysis	p. 424
Solid Earth Geomagnetism	p. 427
Upper Atmospheric Studies	p. 437
Perspective	p. 449
Solid Earth Geomagnetism	p. 452
Current Trends/Geomagnetism	p. 458
Select Bibliography	p. 460
Index	p. 477
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