Geoelectromagnetic Investigation of the Earth’s Crust and Mantle
Geoelectromagnetic Investigation of the Earth’s Crust and Mantle

Author: I.I. Rokityansky

Publisher: Springer Science & Business Media

Published: 2012-12-06

Total Pages: 394

ISBN-13: 3642618014

DOWNLOAD EBOOK

Electrical conductivity is a parameter which characterizes composition and physical state of the Earth's interior. Studies of the state equations of solids at high temperature and pressure indicate that there is a close relation be tween the electrical conductivity of rocks and temperature. Therefore, measurements of deep conductivity can provide knowledge of the present state and temperature of the Earth's crust and upper mantle matter. Infor mation about the temperature of the Earth's interior in the remote past is derived from heat flow data. Experimental investigation of water-containing rocks has revealed a pronounced increase of electrical conductivity in the temperature range D from 500 to 700 DC which may be attributed to the beginning of fractional melting. Hence, anomalies of electrical conductivity may be helpful in identitying zones of melting and dehydration. The studies of these zones are perspective in the scientific research of the mobile areas of the Earth's crust and upper mantle where tectonic movements, processes ofthe region al metamorphism and of forming mineral deposits are most intensive. Thus, in the whole set of research on physics of the Earth the studies of electrical conductivity of deep-seated rocks appear, beyond doubt, very important.

Induction Soundings of the Earth's Mantle
Induction Soundings of the Earth's Mantle

Author: Vladimir Semenov

Publisher: Springer

Published: 2017-07-27

Total Pages: 114

ISBN-13: 3319537954

DOWNLOAD EBOOK

At the heart of this book is the generalized theoretical approach that is applied to investigate the geoelectrical structure of the Earth’s mantle. It also analyzes the results of regional and global induction sounding of the Earth’s mantle and compares them with the results obtained by other geophysical methods. The generalized theoretical approach employs the Induction Law as a basis for identifying extended relations between magnetic field components, including their plane divergence, impedances and spatial derivatives. The estimations of impedance values and spatial derivatives are performed using the theory of stochastic processes. The book also considers the external sources of magnetic fields used for sounding the Earths mantle from the modern theory perspective, as well as the problem of coincidence of magneto-variation and magnetotelluric methods. Further, it discusses secular variations in the Earth’s resistance caused by non-induction sources, factors that are correlated with the number of earthquakes in the region and shifted in time with global indexes. It is a valuable resource for scientists applying deep induction soundings or interested in the structures of and processes in the Earth’s interior.

Electromagnetism and the Earth's Interior
Electromagnetism and the Earth's Interior

Author: Tsuneji Rikitake

Publisher: Elsevier

Published: 2012-12-02

Total Pages: 321

ISBN-13: 0323162509

DOWNLOAD EBOOK

Electromagnetism and the Earth's Interior reviews the earth's magnetic fields in terms of physical processes that are occurring in the earth's interior. The book describes the distribution of the earth's magnetic field in terms of declination, horizontal intensity, and vertical intensity. The dynamo theory concerns the self-exciting electric generation in the interior of the earth, and can account for any geomagnetic secular variation. A workable laboratory model—a dynamo mechanism of Lowes and Wilkinson (1963) has a significant role on the dynamo theory for the model actually demonstrated Herzenberg's proof that was developed mathematically. The text also describes various aspects of long-term geomagnetic variations, such as the decrease in the dipole moment, the reversal of the geomagnetic field, the drift of eccentric dipole, the fluctuation in the length of day, and the geomagnetic secular variation. The book also investigates the possible effects of the ocean on geomagnetic variations. The characteristics of transient geomagnetic variations on islands can point to a possible special underground structure. The book is suitable for geologists, astrophysicists, seismologists, and students of the natural sciences.